title: Non-ionizing radiation

text: In addition to the well-known effect of non-ionizing ultraviolet light causing skin cancer, non-ionizing radiation can produce non-mutagenic effects such as inciting thermal energy in biological tissue that can lead to burns. In 2011, the International Agency for Research on Cancer (IARC) from the World Health Organization (WHO) released a statement adding RF electromagnetic fields (including microwave and millimetre waves) to their list of things which are possibly carcinogenic to humans.


title: Non-ionizing radiation

text: In terms of potential biological effects, the non-ionizing portion of the spectrum can be subdivided into:


title: Non-ionizing radiation

text: The above effects have only been shown to be due to heating effects. At low power levels where there is no heating effect, the risk of cancer is not significant.


title: Non-ionizing radiation

text: The International Agency for Research on Cancer recently stated that there could be some risk from non-ionizing radiation to humans. But a subsequent study reported that the basis of the IARC evaluation was not consistent with observed incidence trends. This and other reports suggest that there is virtually no way that results on which the IARC based its conclusions are correct.


title: Non-ionizing radiation

text: Ultraviolet light can cause burns to skin and cataracts to the eyes. Ultraviolet is classified into near, medium and far UV according to energy, where near and medium ultraviolet are technically non-ionizing, but where all UV wavelengths can cause photochemical reactions that to some extent mimic ionization (including DNA damage and carcinogenesis). UV radiation above 10 eV (wavelength shorter than 125 nm) is considered ionizing. However, the rest of the UV spectrum from 3.1 eV (400 nm) to 10 eV, although technically non-ionizing, can produce photochemical reactions that are damaging to molecules by means other than simple heat. Since these reactions are often very similar to those caused by ionizing radiation, often the entire UV spectrum is considered to be equivalent to ionization radiation in its interaction with many systems (including biological systems).


title: Non-ionizing radiation

text: For example, ultraviolet light, even in the non-ionizing range, can produce free radicals that induce cellular damage, and can be carcinogenic. Photochemistry such as pyrimidine dimer formation in DNA can happen through most of the UV band, including much of the band that is formally non-ionizing. Ultraviolet light induces melanin production from melanocyte cells to cause sun tanning of skin. Vitamin D is produced on the skin by a radical reaction initiated by UV radiation.


title: Non-ionizing radiation

text: Plastic (polycarbonate) sunglasses generally absorb UV radiation. UV overexposure to the eyes causes snow blindness, common to areas with reflective surfaces, such as snow or water.


title: Non-ionizing radiation

text: Light, or visible light, is the very narrow range of electromagnetic radiation that is visible to the human eye (about 400–700 nm), or up to 380–750 nm. More broadly, physicists refer to light as electromagnetic radiation of all wavelengths, whether visible or not.


title: Non-ionizing radiation

text: Infrared (IR) light is electromagnetic radiation with a wavelength between 0.7 and 300 micrometers, which equates to a frequency range between approximately 1 and 430 THz. IR wavelengths are longer than that of visible light, but shorter than that of terahertz radiation microwaves. Bright sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation.


title: Non-ionizing radiation

text: Microwaves are electromagnetic waves with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz. This broad definition includes both UHF and EHF (millimeter waves), and various sources use different boundaries. In all cases, microwave includes the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3mm). Applications include cellphone (mobile) telephones, radars, airport scanners, microwave ovens, earth remote sensing satellites, and radio and satellite communications.


title: Non-ionizing radiation

text: Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may cover a part of the Earth very consistently, shorter waves can reflect off the ionosphere and travel around the world, and much shorter wavelengths bend or reflect very little and travel on a line of sight.


title: Non-ionizing radiation

text: Very low frequency or VLF is the range of RF of 3 to 30 kHz. Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals are used, such as for radio navigation. Also known as the myriametre band or myriametre wave as the wavelengths range from ten to one myriametre (an obsolete metric unit equal to 10 kilometres).


title: Non-ionizing radiation

text: Extremely low frequency (ELF) is the range of radiation frequencies from 300 Hz to 3 kHz. In atmosphere science, an alternative definition is usually given, from 3 Hz to 3 kHz. In the related magnetosphere science, the lower frequency electromagnetic oscillations (pulsations occurring below ~3 Hz) are considered to be in the ULF range, which is thus also defined differently from the ITU Radio Bands.


title: Non-ionizing radiation

text: Thermal radiation, a common synonym for infrared when it occurs at temperatures commonly encountered on Earth, is the process by which the surface of an object radiates its thermal energy in the form of electromagnetic waves. Infrared radiation that one can feel emanating from a household heater, infra-red heat lamp, or kitchen oven are examples of thermal radiation, as is the IR and visible light emitted by a glowing incandescent light bulb (not hot enough to emit the blue high frequencies and therefore appearing yellowish; fluorescent lamps are not thermal and can appear bluer). Thermal radiation is generated when the energy from the movement of charged particles within molecules is converted to the radiant energy of electromagnetic waves. The emitted wave frequency of the thermal radiation is a probability distribution depending only on temperature, and for a black body is given by Planck's law of radiation. Wien's displacement law gives the most likely frequency of the emitted radiation, and the Stefan–Boltzmann law gives the heat intensity (power emitted per area).


title: Non-ionizing radiation

text: Parts of the electromagnetic spectrum of thermal radiation may be ionizing, if the object emitting the radiation is hot enough (has a high enough temperature). A common example of such radiation is sunlight, which is thermal radiation from the Sun's photosphere and which contains enough ultraviolet light to cause ionization in many molecules and atoms. An extreme example is the flash from the detonation of a nuclear weapon, which emits a large number of ionizing X-rays purely as a product of heating the atmosphere around the bomb to extremely high temperatures.


title: Non-ionizing radiation

text: As noted above, even low-frequency thermal radiation may cause temperature-ionization whenever it deposits sufficient thermal energy to raises temperatures to a high enough level. Common examples of this are the ionization (plasma) seen in common flames, and the molecular changes caused by the "browning" in food-cooking, which is a chemical process that begins with a large component of ionization.


title: Non-ionizing radiation

text: "Black-body radiation" is radiation from an idealized radiator that emits at any temperature the maximum possible amount of radiation at any given wavelength. A black body will also absorb the maximum possible incident radiation at any given wavelength. The radiation emitted covers the entire electromagnetic spectrum and the intensity (power/unit-area) at a given frequency is dictated by Planck's law of radiation. A black body at temperatures at or below room temperature would thus appear absolutely black as it would not reflect any light. Theoretically a black body emits electromagnetic radiation over the entire spectrum from very low frequency radio waves to X-rays. The frequency at which the black-body radiation is at maximum is given by Wien's displacement law.


title: Ernst L. Freud

text: Ernst L. Freud (6 April 1892 – 7 April 1970) was an Austrian architect and the fourth child of Austrian psychoanalyst Sigmund Freud and his German-born wife Martha Bernays. In honour of his wife, Ernst Freud added the initial L. to his name when he married in early 1920, making the middle initial stand for Lucie and not Ludwig as is often assumed.


title: Ernst L. Freud

text: Freud was born in Vienna. In 1920, he established his practice in Berlin, where a large number of his clients were doctors. The majority of his commissions were for houses and consulting rooms and he worked in an Art Deco style but by 1930 had begun to work in a modern style showing the influence of Mies van der Rohe. Examples of this include a cigarette factory in Berlin and a house for Dr. Frank in Geltow near Potsdam. Dr. Frank was a manager of Deutsche Bank until he was forced to give up his position in 1933 and into exile in 1938.


title: Ernst L. Freud

text: In 1933, with the rise to power of the Nazis, Ernst Freud left Berlin for London where he settled in St. John's Wood. He secured a number of commissions for private houses and blocks of flats around Hampstead including the notable Frognal Close in 1938, Belvedere Court, Lyttelton Road and a consulting room for Melanie Klein. Ernst Freud, his wife and children were naturalised British subjects at the end of August 1939.


title: Ernst L. Freud

text: In 1938, Ernst Freud's parents and younger sister Anna Freud joined the family in London and moved into a house in Hampstead that Ernst remodelled including the creation of a glazed garden room. The house today is the Freud Museum. After Sigmund Freud's death in 1939, Ernst Freud organised the funeral arrangements at the Golders Green Crematorium, with "Harrods" as funeral directors. Ernst Freud also later designed the marble plinth on which Sigmund Freud's urn was placed.


title: Ernst L. Freud

text: For the last three years of his life, following a heart attack that forced his retirement as an architect, Freud devoted his time to editing his father's correspondence, a project that had long been his spare‐time occupation. He was the editor of "Letters of Sigmund Freud", published in New York in 1960, and he was co-editor of "Psychoanalysis and Faith The Letters of Sigmund Freud and Oskar Pfister", published in New York in 1964.


title: Ernst L. Freud

text: Freud married Lucie Brasch, daughter of Joseph Brasch, a wealthy Berlin corn merchant. Lucie had studied classical philology in Berlin and Munich, as well as art history with Heinrich Wölfflin in Munich. To honour his wife, Ernst Freud added the middle initial L, for Lucie, to his name.


title: Ernst L. Freud

text: Ernst and Lucie had three sons: Stephen Gabriel Freud (1921–2015), an ironmonger; the painter Lucian Freud (1922–2011), who was named after his mother; and the politician and broadcaster Clement Freud (1924–2009).


title: Ernst L. Freud

text: Clement Freud wrote a memoir in which, according to journalist Harriet Lane, "there are a few moments when indignation or irritation surge to the surface. In conversation, he is prepared to go further. In the book, for instance, he fudges his parents' non-appearance at his 1950 church wedding to actress Jill Raymond (who now runs two theatre companies in Suffolk). My interpretation had been that they had not been invited. But he corrects me on this. They were asked but chose, as atheists, not to attend."


title: Demand forecasting

text: Demand forecasting is known as the process of making future estimations in relation to customer demand over a specific period. Generally, demand forecasting will consider historical data and other analytical information to produce the most accurate predictions. More specifically, the methods of demand forecasting entails using predictive analytics of historical data to understand and predict customer demand in order to understand key economic conditions and assist in making crucial supply decisions to optimise business profitability. Demand forecasting methods are divided into two major categories, qualitative and quantitative methods. Qualitative methods are based on expert opinion and information gathered from the field. It is mostly used in situations when there is minimal data available to analyse. For example, when a business or product is newly being introduced to the market. Quantitative methods however, use data, and analytical tools in order to create predictions. Demand forecasting may be used in production planning, inventory management, and at times in assessing future capacity requirements, or in making decisions on whether to enter a new market.


title: Demand forecasting

text: Demand forecasting plays an important role for businesses in different industries, particularly in reducing risk in business activities. However, it is known to be a challenge that companies face due to the intricacies of analysis, specifically quantitative analysis. Yet, understanding customer needs is an indispensable part of any industry, so that business plans can be implemented more efficiently and can more appropriately respond to market needs. If businesses begin to master the concept of demand forecasting, it can result in several benefits. These include, but are not limited to, waste reduction, more optimal allocation of resources and potentially dramatic increases in sales and revenue.


title: Demand forecasting

text: There are various statistical and econometric analyses used to forecast demand. Forecasting demand can be broken down into seven stage process, the seven stages are described as:


title: Demand forecasting

text: The first step to forecast demand is to determine a set of objectives or information to derive different business strategies (find journal). These objectives are based on a set of hypotheses which usually come from a mixture of economic theory or previous empirical studies. For example, a manager may wish to find what the optimal price and production amount would be for a new product, based on how demand elasticity affected past company sales.


title: Demand forecasting

text: There are many different econometric models which differ depending on the analysis that managers wish to perform. The type of model that is chosen to forecast demand depends on many different aspects such as the type of data obtained or the number of observations, etc. In this stage it is important to define the type of variables that will be used to forecast demand. Regression analysis is the main statistical method for forecasting. There are many different types of regression analysis but fundamentally, they provide an analysis of how one or multiple variables affect the dependent variable being measured. An example of a model for forecasting demand is M.Roodman’s (1986) demand forecasting regression model for measuring the seasonality affects on a data point being measured. The model was based on a linear regression model, and is used to measure linear trends based on seasonal cycles and their affects on demand ie. the seasonal demand for a product based on sales in summer and winter.


title: Demand forecasting

text: Where formula_2 is the dependent variable, formula_3 is the intercept, formula_4 is the slope coefficient, formula_5 is the independent variable and is the error term.


title: Demand forecasting

text: formula_7 is defined as the set of all  - indices for quarter . The process that generates the data for all periods  that fall in quarter  is given by:


title: Demand forecasting

text: Once the type of model is specified in stage 2, the data and the method of collecting data must be specified. The model must be specified first in order to determine the variables which need to be collected. Conversely, when deciding on the desired forecasting model, the available data or methods to collect data needs to be considered in order to formulate the correct model. Time series data and cross section data are the different collection methods that can be used. Time series data are based on historical observations taken sequentially in time. These observations are used to derive relevant statistics, characteristics, and insight from the data. The data points that may be collected using time series data may be sales, prices, manufacturing costs and their corresponding time intervals i.e., weekly, monthly, quarterly, annually or any other regular interval.  Cross section data refers to data collected on a single entity at different periods of time. Cross sectional data used in demand forecasting usually depicts a data point gathered from an individual, firm, industry or an area. For example, sales for Firm A during quarter 1. This type of data encapsulates a variety of data points which resulted in the final data point. The subset of data points may not be observable or feasible to determine but can be practical method for adding precision to the demand forecast model. The source for the data can be found via the firm’s records, commercial or private agencies or official sources.


title: Demand forecasting

text: Once the model and data are obtained then computing the values to determine the affects the independent variables have on the dependant variable in focus. Using the linear regression model as an example of estimating parameters, the following steps are taken:


title: Demand forecasting

text: The first step is to find the line that minimizes the sum of the squares of the difference between the observed values of the dependent variable and the fitted values from the line. This is expressed as formula_12 which minimizes formula_13 and formula_14 fitted value from the regression line.


title: Demand forecasting

text: formula_3 and formula_4 also need to be represented to fine the intercept and slope of the line. The method of determining formula_3 and formula_4 is to use partial differentiation withe respect to both formula_3 and formula_4 by setting both expressions equal to zero and solving them simultaneously. The method for omitting these variables are described below:


title: Demand forecasting

text: Calculating demand forecast accuracy is the process of determining the accuracy of forecasts made regarding customer demand for a product. Understanding and predicting customer demand is vital to manufacturers and distributors to avoid stock-outs and maintain adequate inventory levels. While forecasts are never perfect, they are necessary to prepare for actual demand. In order to maintain an optimized inventory and effective supply chain, accurate demand forecasts are imperative.


title: Demand forecasting

text: Forecast accuracy in the supply chain is typically measured using the Mean Absolute Percent Error or MAPE. Statistically MAPE is defined as the average of percentage errors.


title: Demand forecasting

text: Most practitioners, however, define and use the MAPE as the Mean Absolute Deviation divided by Average Sales, which is just a volume weighted MAPE, also referred to as the MAD/Mean ratio. This is the same as dividing the sum of the absolute deviations by the total sales of all products. This calculation formula_22, where is the actual value and the forecast, is also known as WAPE, Weighted Absolute Percent Error.


title: Demand forecasting

text: formula_23. The advantage of this measure is that could weight errors, so you can define how to weight for your relevant business, ex gross profit or ABC. The only problem is that for seasonal products you will create an undefined result when sales = 0 and that is not symmetrical, that means that you can be much more inaccurate if sales are higher than if they are lower than the forecast. So sMAPE is also used to correct this, it is known as symmetric Mean Absolute Percentage Error.


title: Demand forecasting

text: Last but not least, for intermittent demand patterns none of the above are really useful. So you can consider MASE (Mean Absolute Scaled Error) as a good KPI to use in those situations, the problem is that is not as intuitive as the ones mentioned before. Another metric to consider, especially when there are intermittent or lumpy demand patterns at hand, is SPEC (Stock-keeping-oriented Prediction Error Costs). The idea behind this metric is to compare predicted demand and actual demand by computing theoretical incurred costs over the forecast horizon. It assumes, that predicted demand higher than actual demand results in stock-keeping costs, whereas predicted demand lower than actual demand results in opportunity costs. SPEC takes into account temporal shifts (prediction before or after actual demand) or cost-related aspects and allows comparisons between demand forecasts based on business aspects as well.


title: Demand forecasting

text: The forecast error needs to be calculated using actual sales as a base. There are several forms of forecast error calculation methods used, namely Mean Percent Error, Root Mean Squared Error, Tracking Signal and Forecast Bias.


title: Demand forecasting

text: Once the model has been determined, the model is used to test the theory or hypothesis stated in the first stage. The results should describe what is trying to be achieved and determine if the theory or hypothesis is true or false. In relation to the example provided in the first stage, the model should show the relationship between demand elasticity of the market and the correlation it has to past company sales. This should enable managers to make an informed decisions regarding the optimal price and production amount for the new product.


title: Demand forecasting

text: The final step is to then forecast demand based on the data set and model created. In order to forecast demand, estimations of a chosen variable are used to see the affects it has on demand. Regarding estimating the chosen variable, a regression model can be used or both qualitative and quantitative assessments can be implemented. Examples of qualitative and quantitative assessments are:


title: Mesquite, Nevada

text: Mesquite is a city in Clark County, Nevada, United States adjacent to the Arizona state line and northeast of Las Vegas on Interstate 15. As of the 2020 census, the city had a population of 20,471. The city is located in the Virgin River valley adjacent to the Virgin Mountains in the northeastern part of the Mojave Desert. It is home to a growing retirement community, as well as several casino resorts and golf courses.


title: Mesquite, Nevada

text: Mesquite was settled by Mormon pioneers in 1880, who called it "Mesquite Flat". The community was finally established on the third attempt after having been flooded out from the waters of the Virgin River. The name was later shortened to Mesquite, and the city was incorporated 1984. The community was named for the mesquite timber near the original town site. Mesquite, like nearby Bunkerville, had its origins in farming. The Peppermill Mesquite casino, which opened in the 1970s, drove Mesquite's diversified economy. The city incorporated in 1984 and established a master development plan during the early 1990s. In the mid-1990s, more casinos opened. By 2006, Mesquite was one of the fastest-growing small towns in the United States, though the late-2000s recession led to the closure of the Oasis (formerly the Peppermill) casino.


title: Mesquite, Nevada

text: Mesquite occupies the northeast corner of Clark County. The eastern border of the city is the Arizona state line. The city is in the Virgin River valley, occupying the northern side of the river. The city lies adjacent to the Virgin Mountains in the northeastern Mojave Desert near the southern mouth of the Virgin River Gorge.


title: Mesquite, Nevada

text: Interstate 15 passes through the city, leading southwest to downtown Las Vegas and northeast to St. George, Utah. Nevada State Route 170 leads south from the center of town, crossing the Virgin River into the unincorporated community of Bunkerville before looping back to I-15 at the western city limits of Mesquite.


title: Mesquite, Nevada

text: According to the U.S. Census Bureau, the city of Mesquite has a total area of , of which is land and , or 1.40%, is water.


title: Mesquite, Nevada

text: As of the census of 2010, there were 15,276 people, 8,911 houses, 6,378 Houses occupied, and 4,444 families residing in the city. The population density was 613.3 per square mile (236.8/km) in the year 2000. There were 4,442 housing units at an average density of 290.1 per square mile (112.0/km). The racial makeup of the city was 80.30% White, 1.27% Asian, 0.98% Native American, 0.65% African American, 0.07% Pacific Islander, 14.56% from other races, and 2.17% from two or more races. Hispanic or Latino of any race were 24.75% of the population. There were 3,498 households, out of which 28.7% had children under the age of 18 living with them, 62.8% were married couples living together, 7.2% had a female householder with no husband present, and 26.5% were non-families. Of all households, 20.4% were made up of individuals, and 7.4% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.08.


title: Mesquite, Nevada

text: In the city, the population was spread out, with 25.6% under the age of 18, 7.7% from 18 to 24, 22.8% from 25 to 44, 27.3% from 45 to 64, and 16.6% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 103.8 males. For every 100 females age 18 and over, there were 104.0 males. The median income for a household in the city was $40,392, and the median income for a family was $42,941. Males had a median income of $27,083 versus $24,402 for females. The per capita income for the city was $20,191. About 6.2% of families and 10.2% of the population were below the poverty line, including 18.3% of those under age 18 and 6.0% of those age 65 or over.


title: Mesquite, Nevada

text: The city of Mesquite is a part of the Clark County School District. There are four public schools in the valley.


title: Mesquite, Nevada

text: Located within the Mojave Desert, Mesquite experiences a desert climate with a large degree of diurnal temperature variation. Roughly 500 ft lower than Las Vegas, Mesquite is typically about 3 degrees Fahrenheit hotter than Las Vegas. Unlike Las Vegas, Mesquite lacks an urban heat island. This makes low temperatures noticeably more comfortable in the summer, but means Winter nights are colder.


title: Mesquite, Nevada

text: Like other weather stations in the Mojave and Sonoran desert, the annual temperature cycle is asymmetric, with a seasonal lag of roughly 1 month in summer, and a seasonal lead in winter. The hottest time of the year on average is July 21, with an average high of 106 and low of 72. Conversely, the normal high temp drops to the lowest value of the year, 57 degrees, and low of 28 on December 16, approximately 6 days before the winter solstice. This seasonal lag in summer and seasonal lead in winter can be found in other climate stations in the same region.


title: Mesquite, Nevada

text: In 1987, the Virgin Valley's first newspaper, "The Desert Echo", began distribution out of a local home on Riverside Road. "The Desert Valley Times" emerged by 1995, and "The Desert Echo" merged with "The Desert Valley Times" in 1998. Around 2000/2001, St. George–based "The Spectrum" (a Gannett newspaper) bought and distributed "The Desert Valley Times".


title: Mesquite, Nevada

text: Mesquite is home to several casinos, including the Virgin River Casino, CasaBlanca, Eureka, and Stateline Casino and Motel. The city also includes Rising Star Sports Ranch, a non-gaming hotel and sports facility. The Virgin Valley Heritage Museum has exhibits about area pioneers and local history. The museum building, built in 1940, is listed in the National Register of Historic Places. Mesquite is a stopping point for those traveling along I-15 between Salt Lake City, Las Vegas, and Los Angeles. Mesquite is also a destination for year-round golf, with over nine public courses in the warm desert climate, it draws golfers from all over. Mesquite Airport provides facilities for general aviation and skydiving. It previously hosted the annual RE/MAX World Long Drive Championship until 2015.


title: Marvelous (company)

text: The announcement of merging Marvelous Entertainment Inc., AQ Interactive, Inc., Liveware Inc. in to Marvelous AQL Inc. on October 1, 2011 was originally proposed by Marvelous Entertainment Inc., and went effective on May 10, 2011. The plan would make Marvelous Entertainment Inc. the sole surviving entity after the merger, with Marvelous Entertainment Inc. renamed to Marvelous AQL Inc. on merger day.


title: Marvelous (company)

text: On December 22, 2011, MarvelousAQL Inc. announced the establishment of the overseas business department, with investment from Checkpoint Studios Inc., replacing the global strategy room, which dissolved on January 1, 2012.


title: Marvelous (company)

text: On October 25, 2012, MarvelousAQL Inc. announced its stock listing on the first section of the Tokyo Stock Exchange, effective on November 1, 2012.


title: Marvelous (company)

text: On January 1, 2013, MarvelousAQL Inc. established the amusement business division. The company's digital contents business division and amusement contents development division were moved into amusement business division, and was renamed as amusement development division.


title: Marvelous (company)

text: On March 13, 2015, it was announced that Marvelous would acquire mobile gaming company G-Mode. This includes Data East IPs that G-Mode bought in 2004.


title: Access-control list

text: In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. Each entry in a typical ACL specifies a subject and an operation. For instance, if a file object has an ACL that contains , this would give Alice permission to read and write the file and give Bob permission only to read it.


title: Access-control list

text: Many kinds of operating systems implement ACLs or have a historical implementation; the first implementation of ACLs was in the filesystem of Multics in 1965.


title: Access-control list

text: A filesystem ACL is a data structure (usually a table) containing entries that specify individual user or group rights to specific system objects such as programs, processes, or files. These entries are known as access-control entries (ACEs) in the Microsoft Windows NT, OpenVMS, and Unix-like operating systems such as Linux, macOS, and Solaris. Each accessible object contains an identifier to its ACL. The privileges or permissions determine specific access rights, such as whether a user can read from, write to, or execute an object. In some implementations, an ACE can control whether or not a user, or group of users, may alter the ACL on an object.


title: Access-control list

text: One of the first operating systems to provide filesystem ACLs was Multics. PRIMOS featured ACLs at least as early as 1984.


title: Access-control list

text: In the 1990s the ACL and RBAC models were extensively tested and used to administer file permissions.


title: Access-control list

text: POSIX 1003.1e/1003.2c working group made an effort to standardize ACLs, resulting in what is now known as "POSIX.1e ACL" or simply "POSIX ACL". The POSIX.1e/POSIX.2c drafts were withdrawn in 1997 due to participants losing interest for funding the project and turning to more powerful alternatives such as NFSv4 ACL. , no live sources of the draft could be found on the Internet, but it can still be found in the Internet Archive.


title: Access-control list

text: Most of the Unix and Unix-like operating systems (e.g. Linux since 2.5.46 or November 2002, FreeBSD, or Solaris) support POSIX.1e ACLs (not necessarily draft 17). ACLs are usually stored in the extended attributes of a file on these systems.


title: Access-control list

text: NFSv4 ACLs are much more powerful than POSIX draft ACLs. Unlike draft POSIX ACLs, NFSv4 ACLs are defined by an actually published standard, as part of the Network File System.


title: Access-control list

text: NFSv4 ACLs are supported by many Unix and Unix-like operating systems. Examples include AIX, FreeBSD, Mac OS X beginning with version 10.4 ("Tiger"), or Solaris with ZFS filesystem, support NFSv4 ACLs, which are part of the NFSv4 standard. There are two experimental implementations of NFSv4 ACLs for Linux: NFSv4 ACLs support for Ext3 filesystem and the more recent Richacls, which brings NFSv4 ACLs support for Ext4 filesystem. As with POSIX ACLs, NFSv4 ACLs are usually stored as extended attributes on Unix-like systems.


title: Access-control list

text: NFSv4 ACLs are organized nearly identically to the Windows NT ACLs used in NTFS. NFSv4.1 ACLs are a superset of both NT ACLs and POSIX draft ACLs. Samba supports saving the NT ACLs of SMB-shared files in many ways, one of which is as NFSv4-encoded ACLs.


title: Access-control list

text: Microsoft's Active Directory service implements an LDAP server that store and disseminate configuration information about users and computers in a domain. Active Directory extends the LDAP specification by adding the same type of access-control list mechanism as Windows NT uses for the NTFS filesystem. Windows 2000 then extended the syntax for access-control entries such that they could not only grant or deny access to entire LDAP objects, but also to individual attributes within these objects.


title: Access-control list

text: On some types of proprietary computer hardware (in particular, routers and switches), an access-control list provides rules that are applied to port numbers or IP addresses that are available on a host or other layer 3, each with a list of hosts and/or networks permitted to use the service. Although it is additionally possible to configure access-control lists based on network domain names, this is a questionable idea because individual TCP, UDP, and ICMP headers do not contain domain names. Consequently, the device enforcing the access-control list must separately resolve names to numeric addresses. This presents an additional attack surface for an attacker who is seeking to compromise security of the system which the access-control list is protecting. Both individual servers and routers can have network ACLs. Access-control lists can generally be configured to control both inbound and outbound traffic, and in this context they are similar to firewalls. Like firewalls, ACLs could be subject to security regulations and standards such as PCI DSS.


title: Access-control list

text: ACL algorithms have been ported to SQL and to relational database systems. Many "modern" (2000s and 2010s) SQL-based systems, like enterprise resource planning and content management systems, have used ACL models in their administration modules.


title: Access-control list

text: The main alternative to the ACL model is the role-based access-control (RBAC) model. A "minimal RBAC model", "RBACm", can be compared with an ACL mechanism, "ACLg", where only groups are permitted as entries in the ACL. Barkley (1997) showed that "RBACm" and "ACLg" are equivalent.


title: Access-control list

text: In modern SQL implementations, ACLs also manage groups and inheritance in a hierarchy of groups. So "modern ACLs" can express all that RBAC express and are notably powerful (compared to "old ACLs") in their ability to express access-control policy in terms of the way in which administrators view organizations.


title: Sam Vaknin

text: Shmuel "Sam" Vaknin (born April 21, 1961) is an Israeli writer and professor of psychology. He is the author of "Malignant Self Love: Narcissism Revisited" (1999), was the last editor-in-chief of the now-defunct political news website Global Politician, and runs a private website about narcissistic personality disorder (NPD). He has also postulated a theory on chronons and time asymmetry.


title: Sam Vaknin

text: Vaknin was born in Kiryat Yam, Israel, the eldest of five children born to Sephardi Jewish immigrants. Vaknin's mother was from Turkey, and his father, a construction worker, was from Morocco. He describes a difficult childhood, in which he writes that his parents "were ill-equipped to deal with normal children, let alone the gifted".


title: Sam Vaknin

text: He left home to serve in the Israel Defense Forces from 1979 to 1982 in training and education units. Between 1980 and 1983 he founded a chain of computerized information kiosks in Tel Aviv, and in 1982 worked for the Nessim D. Gaon Group in Geneva, Paris, and New York City.


title: Sam Vaknin

text: In the mid-1980s, he became aware of difficulties in his relationship with his fiancée, and that he had mood swings. In 1985 he sought help from a psychiatrist, who diagnosed him with narcissistic personality disorder (NPD). Vaknin did not accept the diagnosis at the time.


title: Sam Vaknin

text: From 1986 to 1987 he was the general manager of IPE Ltd. in London. He moved back to Israel, where he became director of an Israeli investment firm, Mikbatz Teshua. He was also president of the Israeli chapter of the Unification Church's Professors for World Peace Academy.


title: Sam Vaknin

text: In Israel in 1995 he was found guilty on three counts of securities fraud along with two other men, Nissim Avioz and Dov Landau. He was sentenced to 18 months' imprisonment and fined 50,000 shekels (about $14,000), while the company was fined 100,000 shekels. In 1996, as a condition of parole, he agreed to a mental health evaluation, which noted various personality disorders. According to Vaknin, "I was borderline, schizoid, but the most dominant was NPD," and on this occasion he accepted the diagnosis, because, he wrote, "it was a relief to know what I had."


title: Sam Vaknin

text: Vaknin moved to Skopje, Macedonia, where he married Macedonian Lidija Rangelovska. They set up Narcissus Publications in 1997, which publishes Vaknin's work. Between 2001 and 2003, Vaknin was a Senior Business Correspondent for United Press International. He has also written for "Central Europe Review" about political issues in the Balkans, as well as for the "Middle East Times". Until a few weeks before the September 2002 Macedonian election, he served as an adviser to Macedonia's Ministry of Finance. He writes regularly for other publications, such as the International Analyst Network, and the online "American Chronicle".


title: Sam Vaknin

text: Vaknin is visiting professor at Southern Federal University in Rostov Oblast, Russia in 2017–22 holding a course of lectures there on personality theory in psychology. He is also a professor of finance and a professor of psychology in the Centre for International Advanced and Professional Studies (CIAPS) in Nigeria.


title: Sam Vaknin

text: A model of quantised time was proposed by Vaknin in his 1982 Ph.D. dissertation, titled "Time Asymmetry Revisited". The dissertation was published by Pacific Western University (California). The dissertation submitted postulates the existence of a particle (chronon). In the proposed theory, time is the result of the interaction of chronons, very much as other forces in nature are the result of other particle interactions. Vaknin postulates the existence of various time quarks (up, down, colors, etc.) whose properties cancel each other and thus the arrow of time is derived (time asymmetry). The postulated particle (chronon) is not only an ideal clock, but also mediates time itself (analogous to the relationship between the Higgs boson and mass). In other words, what we call "time" is the interaction between chronons in a field. Chronons exchange between them a particle and thereby exert a force. "Events" are perturbations in the Time Field and they are distinct from chronon interactions. Chronon interactions (particle exchanges) in the Time Field generate "time" and "time asymmetry" as we observe them.


title: Sam Vaknin

text: Vaknin has a prolific online presence, writing on narcissism and psychopathy. His views have been solicited by the media.


title: Sam Vaknin

text: In his view, narcissists have lost their "true self", the core of their personality, which has been replaced by delusions of grandeur, a "false self". Therefore, he believes, they cannot be healed, because they do not exist as real persons, only as reflections: "The False Self replaces the narcissist's True Self and is intended to shield him from hurt and narcissistic injury by self-imputing omnipotence… The narcissist pretends that his False Self is real and demands that others affirm this confabulation," meanwhile keeping his real-life imperfect true self under wraps. Vaknin extends the concept of narcissistic supply, and introduces concepts such as primary and secondary narcissistic supply. He distinguishes between cerebral and somatic narcissists; the former generate their narcissistic supply by applying their minds, the latter their bodies. He considers himself a cerebral narcissist. He calls narcissistic co-dependents "inverted narcissists." "[They] provide the narcissist with an obsequious, unthreatening audience… the perfect backdrop." He believes that disproportionate numbers of pathological narcissists are at work in the most influential reaches of society, such as medicine, finance and politics.


title: Sam Vaknin

text: Vaknin developed a new treatment modality for narcissism and depression, dubbed "Cold Therapy". It is based on recasting pathological narcissism as a form of CPTSD (Complex Post-traumatic Stress Disorder) and arrested development which result in an addictive personality with a dysfunctional attachment style. The therapy uses re-traumatization and a form of reframing.


title: Sam Vaknin

text: In 2007, Vaknin appeared in the episode "Egomania" of the British Channel 4 documentary series "Mania".


title: Sam Vaknin

text: In 2009, he was the subject of an Australian documentary film, "I, Psychopath", directed by Ian Walker. In the film, Vaknin underwent a psychological evaluation in which he met the criteria for psychopathy according to the Hare Psychopathy Checklist, but did not meet the criteria for narcissism.


title: Sam Vaknin

text: In 2016, Vaknin appeared in the documentary "How Narcissists Took Over the World" produced by Vice Media.


title: Sam Vaknin

text: In 2019, Vaknin appeared in the online documentary "Plugged-in: The True Toxicity of Social Media Revealed" produced by Richard Grannon.


title: German rearmament

text: German rearmament ("Aufrüstung", ) was a policy and practice of rearmament carried out in Germany during the interwar period (1918–1939), in violation of the Treaty of Versailles which required German disarmament after WWI to prevent Germany from starting another war. It began on a small, secret, and informal basis shortly after the treaty was signed, but it was openly and massively expanded after the Nazi Party came to power in 1933.


title: German rearmament

text: Despite its scale, German re-armament remained a largely covert operation, carried out using front organizations such as glider clubs for training pilots and sporting clubs, and Nazi SA militia groups for teaching infantry combat techniques. Front companies like MEFO were set up to finance the rearmament by placing massive orders with Krupp, Siemens, Gutehofnungshütte, and Rheinmetall for weapons forbidden by the Treaty of Versailles.


title: German rearmament

text: Carl von Ossietzky exposed the reality of the German rearmament in 1931 and his disclosures won him the 1935 Nobel Peace Prize but he was imprisoned and tortured by the Nazis, dying of tuberculosis in 1938. Von Ossietzky's disclosures also triggered the re-armament policy in Great Britain, which escalated after Adolf Hitler withdrew Germany from the League of Nations and the World Disarmament Conference in 1933.


title: German rearmament

text: Despite notable warnings by von Ossietzky, Winston Churchill and others, successive governments across Europe failed to effectively recognize, cooperate, and respond to the potential danger posed by Germany's re-armament. Outside of Germany, a global disarmament movement was popular after World War I and Europe's democracies continued to elect governments that supported disarmament even as Germany pursued re-armament. By the late 1930s, the German military was easily capable of overwhelming its neighbors and the rapidly successful German conquests of Poland, Denmark, Norway, the Netherlands, Belgium, Luxembourg, and France proved just how poorly prepared Germany's neighbors were to defend themselves.


title: German rearmament

text: Germany's post-1918 rearmament began at the time of the Weimar Republic, when the Chancellor of Germany Hermann Müller, who belonged to the Social Democratic Party (SPD), passed cabinet laws that allowed secret and illegal rearmament efforts. During its early years (1918–1933), the rearmament was relatively small, secret, and supported by a cross-section of Germans motivated by a mixture of patriotism-based nationalism and economics-based nationalism. The latter motive viewed the Treaty of Versailles, which was ostensibly about war reparations and peace enforcement. France wanted to make sure Germany would never again be a military threat. However, in the mid-1930s Britain and France would decline to fight another war to enforce the Versailles Treaty, thus bringing the treaty's effects to an end.


title: German rearmament

text: An example of the Weimar clandestine rearmament measures was the training and equipping of police forces in a way that made them not just paramilitary in organizational culture (which most police forces are, to one degree or another) but also well prepared to rapidly augment the military as military reserve forces, which the treaty did not allow. Another example was that the government tolerated that various Weimar paramilitary groups armed themselves to a dangerous degree. Their force grew enough to potentially threaten the state, but this was tolerated because the state hoped to use such militias as military reserve forces with which to rearm the Reichswehr in the future. Thus various "Freikorps", "Der Stahlhelm", the "Reichsbanner", the Nazi SA, the Nazi SS, and the Ruhr Red Army grew from street gangs into private armies. For example, by 1931 Werner von Blomberg was using the SA in preparation for border defense in East Prussia.


title: German rearmament

text: Another aspect of Weimar era rearmament was massive investment in dual use technologies and fields of military technology which hadn't been mentioned in the Versailles treaty such as rocketry. Walter Dornberger was tasked with developing liquid fuel rockets for military purposes in 1930 and would become involved in the V2 rocket program later. The Deutsche Luft Hansa was never anywhere near profitability and aviation played only a minuscule role in the transportation of either passengers or cargo, but the planes it employed were very similar to then current military models and its existence allowed the growth of the domestic airplane building industry and the training of pilots, both of which could be converted to military use in circumvention of the prohibition of Germany maintaining an Air Force as lined out in the Versailles treaty.


title: German rearmament

text: One of the reasons why this militarization of society was difficult to prevent relates to the distinction between the government executive and the legislature. The democratically elected government, being composed of groups of people, inevitably reflected the factional strife and cultural militarism among the populace. But the German Revolution of 1918–19 had not truly settled what the nature of the German state ought to be; Weimar Germany after its revolution was not very far from civil war—the different factions all hoped to transform the German state into the one that they thought it should be (which would require violent suppression of the other factions), and they expected their private armies to merge into the state's army (the Reichswehr) if they could manage to come to power. During the Republic's era of democracy, they all participated in the democratic definition of coming to power (winning votes), but many of them, on all sides, planned to abolish or diminish democracy in the future, if they could first get into position to do so.


title: German rearmament

text: During the Weimar era, there was extensive economic interaction between Germany and the Soviet Union, and a component of German re-armament was covertly holding military training exercises in the Soviet Union to hide their extent from other countries. Germany–Soviet Union relations of the interwar period were complex, as bellicosity and cooperation coexisted in tortuous combinations.


title: German rearmament

text: After the Nazi takeover of power in January 1933, the Nazis pursued a greatly enlarged and more aggressive version of rearmament. During its struggle for power, the 'National Socialist party' (NSDAP) promised to recover Germany's lost national pride. It proposed military rearmament claiming that the Treaty of Versailles and the acquiescence of the Weimar Republic were an embarrassment for all Germans. The rearmament became the topmost priority of the German government. Hitler would then spearhead one of the greatest expansions of industrial production Germany had ever seen.


title: German rearmament

text: Third Reich Interior Minister Wilhelm Frick, one of the most influential Nazi figures of the time, and Hjalmar Schacht, who (while never a member of the NSDAP) was an initially sympathetic economist, introduced a wide variety of schemes in order to tackle the effects that the Great Depression had on Germany, were the main key players of German rearmament policies (see Reichsbank § Nazi period).


title: German rearmament

text: Dummy companies like MEFO were set up to finance the rearmament; MEFO obtained the large amount of money needed for the effort through the Mefo bills, a certain series of Promissory notes issued by the Government of Nazi Germany.


title: German rearmament

text: Covert organizations like the Deutsche Verkehrsfliegerschule were established under a civilian guise in order to train pilots for the future Luftwaffe. Although available statistics do not include non-citizens or women, the massive Nazi re-armament policy almost led to full employment during the 1930s. The re-armament began a sudden change in fortune for many factories in Germany. Many industries were taken out of a deep crisis that had been induced by the Great Depression.


title: German rearmament

text: The creation of Mefo bills was the first fiscal step that Germany took on the road to rearmament. The Versailles Treaty prohibited the German government from rearming. Therefore, to rearm to the capacity that Hitler was trying to attain, the Reichsbank would have to extend the German government an almost unlimited amount of credit towards the rearmament program while hiding the accumulation of Government debt from the international community. Contrary to this goal, the then Reichsbank President Hans Luther would only extend credit of one-hundred million Reichsmarks to rearmament, so to work around this, Hitler replaced Luther with Hjalmar Schacht. Schacht turned Luther’s “employment creation bills” program into a system that would allow the German government to receive an unlimited amount of credit to put towards their program. Schacht created the "Metallurgische Forschungs-G.m.b.H", a shell company that would issue short-term treasury notes, which would “function as a concealed form of money.” The company would sell over 12 billion Reichsmarks worth of Mefo-bills by 1938, money which would all go to fund rearmament. Since Schacht’s company did not function and instead just worked as a front for government-issued debt, this allowed the Nazi Regime to conceal their rearmament funding from the international community. Without the creation of the Mefo program, the international community would have been immediately alarmed at the raising of funds by Nazi Germany, and the rearmament program would be threatened by external intervention.


title: German rearmament

text: In another instance of money market fraud, one can examine Schacht’s manipulation of the American international exchange system, which provided Germany an arbitrage opportunity allowing them to fund their rearmament program. After attaining the position of Reichsbank President in 1933, Schacht told the American Government that the German corporations, government, and municipalities would be unable to pay their interest payments to American bondholders on American denominated debt. The cancellation of interest payments was due to the lack of foreign exchange that Germany claimed they had in their treasury. Although German exchange resources had been depleted during the great depression, the German government was not short enough on foreign exchange to completely stop paying bond coupon payments. Instead, the German government wanted to use the foreign exchange to pay for rearmament and fund its activities abroad, an example being the support of Konrad Henlein and the Sudeten German Party In doing this, Schacht realized an arbitrage opportunity. In defaulting on their debt, the Germans would subsequently decrease the value of the debt on the American markets, where they could then go and repurchase the bonds with the “allegedly nonexistent foreign exchange at a fraction of their face value.” The debt purchaser could then sell the bond back to the issuer and exchange it for the American dollar-denominated debt for Reichsmarks. The German government could then take the foreign exchange that they had received and pay for their rearmament program, an example being purchasing American plane parts with the US dollars they accumulated from this program. Schacht took the program even further; he would allow German exporters to use a portion of their foreign exchange reserves to purchase the debt. They would then turn around and sell the debt back to the debtors for Reichsmarks, subsidizing exports at the expense of the bondholder while allowing German debtors to repurchase their debt at a large discount. The American bondholder would risk the value of the bond dropping significantly, or they could resell to the German exporters. Schacht’s plan allowed the Nazi Regime to make a foreign exchange that they could use for rearmament and support their propaganda efforts abroad.


title: German rearmament

text: By 1935, Hitler was open about rejecting the military restrictions set forth by the Treaty of Versailles. Rearmament was announced on 16 March, as was the reintroduction of conscription.


title: German rearmament

text: Some large industrial companies, which had until then specialized in certain traditional products began to diversify and introduce innovative ideas in their production pattern. Shipyards, for example, created branches that began to design and build aircraft. Thus, the German re-armament provided an opportunity for advanced, and sometimes revolutionary, technological improvements, especially in the field of aeronautics.


title: German rearmament

text: Work by labour historians has determined that many German workers in the 1930s identified passionately with the weapons they were building. While this was in part due to the high status of the skilled work required in the armaments industries, it was also to do with the weapons themselves - they were assertions of national strength, the common property of the German nation. Adam Tooze noted in 2008 that an instruction manual given to tank crews during the war made clear this connection:


title: German rearmament

text: For every shell you fire, your father has paid 100 Reichsmarks in taxes, your mother has worked for a week in the factory ... The Tiger costs all told 800,000 Reichsmarks and 300,000 hours of labour. Thirty thousand people had to give an entire week's wages, 6,000 people worked for a week so that you can have a Tiger. Men of the Tiger, they all work for you. Think what you have in your hands!


title: German rearmament

text: The Spanish Civil War (1936–1939) would provide an ideal testing ground for the proficiency of the new weapons produced by the German factories during the re-armament years. Many aeronautical bombing techniques (i.e. dive bombing) were tested by the Condor Legion German expeditionary forces against the Republican Government on Spanish soil with the permission of Generalísimo Francisco Franco. Hitler insisted, however, that his long-term designs were peaceful, a strategy labelled as "Blumenkrieg" ("Flower War").


title: German rearmament

text: Re-armament in the 1930s saw the development of different theories of how to prepare the German economy for total war. The first amongst these was 'defence in depth' which was put forward by Georg Thomas. He suggested that the German economy needed to achieve Autarky (or self-sufficiency) and one of the main proponents behind this was I.G. Farben. Hitler never put his full support behind Autarky and aimed for the development of 'defence in breadth' which espoused the development of the armed forces in all areas and was not concerned with preparing the German war economy.


title: German rearmament

text: The re-armament program quickly increased the size of the German officer corps, and organizing the growing army would be their primary task until the beginning of World War II on September 1, 1939. Count Johann von Kielmansegg (1906–2006) later said that the very involved process of outfitting 36 divisions kept him and his colleagues from reflecting on larger issues.


title: German rearmament

text: In any event, Hitler could boast on 26 September 1938 in the Berlin Sportpalast that after giving orders to rearm the Wehrmacht he could "openly admit: we rearmed to an extent the like of which the world has not yet seen".


title: German rearmament

text: Since World War II, both academics and laypeople have discussed the extent to which German re-armament was an open secret among national governments. The failure of Allied national governments to confront and intercede earlier in Germany is often discussed in the context of the appeasement policies of the 1930s. A central question is whether the Allies should have drawn "a line in the sand" earlier than September 1939, which might have resulted in a less devastating war and perhaps a prevention of the Holocaust. However, it is also possible that anything that caused Hitler not to overreach as soon and as far as he did would only have condemned Europe to a more slowly growing Nazi empire, leaving plenty of time for a Holocaust later, and a successful German nuclear weapons program, safely behind a Nazi version of an iron curtain. George F. Kennan stated: "Unquestionably, such a policy might have enforced a greater circumspection on the Nazi regime and caused it to proceed more slowly with the actualization of its timetable. From this standpoint, firmness at the time of the reoccupation of the Rhineland (7 March 1936) would probably have yielded even better results than firmness at the time of Munich".


title: German rearmament

text: Some 150 American corporations took part in German re-armament, supplying German companies with everything from raw materials to technology and patent knowledge. This took place through a complex network of business interests, joint ventures, cooperation agreements, and cross-ownership between American and German corporations and their subsidiaries. Resources supplied to German companies (some of which were MEFO front companies established by the German state) by American corporations included: synthetic rubber production technology (DuPont and Standard Oil of New Jersey), communication equipment (ITT), computing and tabulation machines (IBM), aviation technology (which was used to develop the Junkers Ju 87 bomber), fuel (Standard Oil of New Jersey and Standard Oil of California), military vehicles (Ford and General Motors), funding (through investment, brokering services, and loans by banks like the Union Banking Corporation), collaboration agreements, production facilities and raw materials. DuPont owned stocks in IG Farben and Degussa AG, who controlled Degesch, the producer of Zyklon B.


title: German rearmament

text: This involvement was motivated not only by financial gain, but in some cases by ideology as well. Irénée du Pont, director and former president of DuPont, was a supporter of Nazi racial theory and a proponent of eugenics.


title: Duchess Helene in Bavaria

text: Helene Caroline Therese (4 April 1834 16 May 1890), nicknamed Néné, was the Hereditary Princess of Thurn and Taxis as the wife of Maximilian Anton Lamoral. She was a Duchess in Bavaria by birth as the daughter of Duke Maximilian Joseph and Princess Ludovika. She was temporarily the head of the Thurn and Taxis family.


title: Duchess Helene in Bavaria

text: Helene’s maternal aunt, Princess Sophie of Bavaria, saw Helene as a good marriage candidate for her son, the future Austrian emperor Franz Josef, and in 1853, Helene, her mother, and her younger sister Elisabeth visited him in Bad Ischl. It was already presumed that Franz Josef would marry Helene, and when he decided to marry Elisabeth instead, Helene was distraught.


title: Duchess Helene in Bavaria

text: In 1858, Helene married Maximilian Anton, Hereditary Prince of Thurn and Taxis. After nearly nine years of marriage, Maximillian died due to a chronic kidney disease, leaving the Thrun and Taxis throne into the hands of Helene until their son reached majority.


title: Duchess Helene in Bavaria

text: Helene Caroline Therese was the third child and eldest daughter of Maximilian Joseph, Duke in Bavaria and Princess Ludovika of Bavaria. She was nicknamed “Néné”.


title: Duchess Helene in Bavaria

text: As a child, Helene and her siblings enjoyed a more carefree and informal upbringing than what was customary for royal children at the time. Their family home during winter was in Munich and Possenhofen Castle on Lake Starnberg during summer.


title: Duchess Helene in Bavaria

text: Helene was unusually pious, and would have fit into the Habsburg court well. She had one quality, though, that would not have been accepted: she was habitually unpunctual, and often missed trains and appointments.


title: Duchess Helene in Bavaria

text: In 1853 Helene traveled with her mother, Ludovika, and her younger sister Elisabeth to the resort of Bad Ischl, Upper Austria, with the hopes that she would become the bride of her cousin Franz Josef, then the Emperor of Austria. He decided that he preferred Elisabeth instead, and a wedding between Helene and the emperor was not cemented.


title: Duchess Helene in Bavaria

text: After the failed engagement, Helene began to suffer from melancholia. Her mother soon became concerned that Helene would take the veil and join a convent. Helene had almost come to terms with remaining single. At 22 years old she was considered to be an "old maid", but her mother arranged for her to meet the wealthy Maximilian Anton Lamoral, Hereditary Prince of Thurn and Taxis. Duke Maximillian Joseph in Bavaria, Helene's father, invited the Thurn and Taxis family to the Possenhofen Castle for a hunting party, at which Prince Maximilian was introduced to Helene.


title: Duchess Helene in Bavaria

text: While the prince was vacationing at Possenhofen, he brought his marriage plans to his parents, who immediately agreed. The only difficulty involved was that although the Thurn and Taxis family were counted among the richest in the land, they were not considered social equals for a princess of royal blood and a member of the House of Wittelsbach. Because of this, King Maximilian II of Bavaria, who was also a cousin of Helene, did not at first agree to a marriage between the two, but through Elisabeth's influence on the king, the marriage took place nevertheless.


title: Duchess Helene in Bavaria

text: The wedding ceremony was held on 24 August 1858 at Possenhofen Castle. To mark the occasion, the in-laws gave the bride a necklace worth 160,000 Gulden. In spite of the earlier objections to the match, Helene is considered to have had the only happy marriage among the five Wittelsbach sisters.


title: Duchess Helene in Bavaria

text: The first child, a daughter, who they named Louisa, was born in 1859, followed by a second daughter, Elisabeth, in 1860. Shortly after the birth of her second child she traveled to Corfu to visit her sister Elisabeth, who was very ill. She returned by way of Vienna, where she reported to Franz Josef on the poor state of his wife.


title: Duchess Helene in Bavaria

text: Helene gave birth to the much-desired son in 1862, named Maximilian Maria, and in 1867 she gave birth to another son named Albert.


title: Duchess Helene in Bavaria

text: Even though the couple had a happy marriage, it was overshadowed by the severe illness of her husband, who had chronic kidney disease. Neither a course of treatment in Karlsbad nor the best doctors could save him. He died in 1867 at only 35 years of age.


title: Duchess Helene in Bavaria

text: Helene took her mind off her sorrows with charitable activities, and received the guardianship of her children from the Austrian emperor. Her father-in-law began to include her in the business affairs of the House of Thurn and Taxis, seeing in her a support and successor. In this way she became the head of the family until her oldest son reached his majority.


title: Duchess Helene in Bavaria

text: In 1883, her son, Maximilian, took over the leadership of the family business, he soon fell ill. His heart had been weakened by scarlet fever in childhood, and he suffered from severe heart spasms. In 1885, he died of a pulmonary embolism. This left Helene the family head again, until 1888 when her son Albert reached his majority and took over the family businesses. Helene then retired and dedicated herself to her religious devotions.


title: Rebecca Nurse

text: Rebecca Nurse (February 13, 1621 – July 19, 1692) was a woman who was accused of witchcraft and executed by hanging in New England during the Salem Witch Trials of 1692. She was fully exonerated fewer than twenty years later.


title: Rebecca Nurse

text: She was the wife of Francis Nurse, had several children and grandchildren, and was a well-respected member of the community. She was tried and convicted in the spring and summer of 1692 and executed on July 19.


title: Rebecca Nurse

text: This occurred during a time when parts of the government and people of the Province of Massachusetts Bay were seized with witch-phobia. Her married sisters Mary Eastey and Sarah Cloyce were also accused. Mary was convicted and executed, but Sarah managed to survive.


title: Rebecca Nurse

text: The daughter of William (c. 1598–1672) and Joanna a Towne (c. 1595/99–1682) (née Blessing), Rebecca Nurse was born in Great Yarmouth, England in 1621. Born February 13, 1621, her baptism is recorded as February 21, 1621. Her family emigrated to the Massachusetts Bay Colony, settling in Salem, although most of the Towne family would eventually move inland to Topsfield. Rebecca had three sisters, Susan (baptized October 26, 1625; died July 29, 1630), Mary (baptized August 24, 1634; executed 1692) and Sarah. She also had three brothers, Edmund (baptized June 1628), Jacob (baptized March 11, 1631 or 1632) and Joseph (born c. 1639).


title: Rebecca Nurse

text: Sometime around 1644, she married Francis Nurse (or Nourse; 1618–1695), who was also born in England. Her husband was a "tray maker" by trade, who likely made many other wooden household items. Due to the rarity of such household goods, such artisans were esteemed. They raised their family in Salem village (modern day Danvers, Massachusetts). The couple had eight children: four daughters and four sons. Their names were John Nurse (born 1645), Rebecca Nurse (born 1647), Samuel Nurse (born 1649), Elizabeth Nurse (born 1655 or 1656), Mary Nurse (born 1657 – 28 June 1749), Francis Nurse (born 1660 or 1661), Sarah Nurse (born 1662) and Benjamin Nurse (born in 1665 or 1666). In 1672, Francis Nurse served as Salem's Constable. It was later written that Rebecca had "acquired a reputation for exemplary piety that was virtually unchallenged in the community," making her one of the "unlikely" persons to be accused of witchcraft.


title: Rebecca Nurse

text: In 1678 they were offered the opportunity to lease-to-own a farm in the rural village area of Salem (today Danvers, Massachusetts), originally a part of a grant given to Townsend Bishop in 1636. This farm still exists, and is today preserved as the Rebecca Nurse Homestead. Rebecca and Francis frequented the Salem Village meeting house and Francis was quite active in the community becoming well respected in Salem Village; he was often asked to serve as mediator to help settle matters. The Nurses officially remained members to the Salem Towne church until their deaths, despite being very active within the village community. In 1699 the Nurses' children were able to officially purchase the farm outright and remained for multiple generations.


title: Rebecca Nurse

text: On March 23, 1692, a warrant was issued for her arrest based upon accusations made by Edward and John Putnam. Upon hearing of the accusations, the frail 71-year-old Nurse, often described as an invalid, said, "I am innocent as the child unborn, but surely, what sin hath God found out in me unrepented of, that He should lay such an affliction on me in my old age."


title: Rebecca Nurse

text: A public outcry greeted the accusations made against her, as she was considered to be a woman of very pious character, who lived in amity with her neighbours, and had a reputation for benevolence as well as piety: even her neighbor Sarah Holton, who had accused Rebecca of acting quite unreasonably in a quarrel over some trespassing pigs, later changed her mind and spoke in Rebecca's defence. Thirty-nine of the most prominent members of the community signed a petition on Nurse's behalf. At age 71, she was one of the oldest accused. The examining magistrates, John Hathorne and Jonathan Corwin, who normally regarded the guilt of the accused as self-evident, took a notably different attitude in Rebecca's case, as they also did in the case of her sister Mary Eastey. They told Rebecca openly that if she was innocent, they prayed that God would show her innocence, for "it is a sad thing to see church members accused". Hathorne was no doubt influenced by the fact that his sister Elizabeth Porter was a close friend of Rebecca, and one of her staunchest defenders.


title: Rebecca Nurse

text: Her trial began on June 30, 1692. In accordance with the procedures at the time, Mrs. Nurse, like others accused of witchcraft, represented herself since she was not allowed to have a lawyer. By dint of her respectability, many members of the community testified on her behalf, including her family members. Often the "afflicted" would break into fits and claim Nurse was tormenting them. Such so-called "spectral evidence" was allowed into the trial to show that Satan was afflicting others in the community at the behest of the accused. In response to their outbursts Nurse stated, "I have got nobody to look to but God."


title: Rebecca Nurse

text: In the end, the jury ruled Nurse not guilty. Due to the public outcry and renewed fits and spasms by the "afflicted", the judges reviewed her case with the jury. One particular point was emphasized, and the jury requested a second chance of deliberation (a legal practice used in those days). The jury asked Rebecca to explain her remark that another accused witch, Deliverance Hobbs, was "of her company", the implication being that they had both signed a pact with the Devil. Fatally, Rebecca, who was hard of hearing, did not hear the question: she later explained to her children that she was referring to this woman as a fellow "accused" witch. However the jury had changed their verdict and sentenced Nurse to death on July 19, 1692. In view of the urgent pleas of her family, and the abundant evidence of her good character, including a moving letter from the foreman of Nurse's jury, the Governor of Massachusetts, Sir William Phips, granted a reprieve, only for it to later be rescinded.


title: Rebecca Nurse

text: Many people described Nurse as "the woman of self-dignity", due to her collected behavior on the gallows. As was the custom, after she was hanged, her body was buried in a shallow grave near the execution spot. They were considered unfit for a Christian burial in a churchyard. According to oral tradition, Nurse's family secretly returned after dark and dug up her body, which they interred properly on their family homestead. Although her exact resting place has never been confirmed her descendants erected a tall granite memorial in the family plot in 1885 at the Rebecca Nurse Homestead cemetery in Danvers (formerly Salem Village), Massachusetts. The inscription on the monument reads:


title: Rebecca Nurse

text: In 1706, her accuser, Ann Putnam, Jr., gave a public church confession upon entering the Salem Village congregation. She expressed great remorse for her role against Rebecca and her two sisters, Mary Eastey and Sarah Cloyce, in particular:


title: Rebecca Nurse

text: "I desire to be humbled before God for that sad and humbling providence that befell my father's family in the year about '92; that I, then being in my childhood, should, by such a providence of God, be made an instrument for the accusing of several persons of a grievous crime, whereby their lives were taken away from them, whom now I have just grounds and good reason to believe they were innocent persons; and that it was a great delusion of Satan that deceived me in that sad time, whereby I justly fear I have been instrumental, with others, though ignorantly and unwittingly, to bring upon myself and this land the guilt of innocent blood; though what was said or done by me against any person I can truly and uprightly say, before God and man, I did it not out of any anger, malice, or ill-will to any person, for I had no such thing against one of them; but what I did was ignorantly, being deluded by Satan. And particularly, as I was a chief instrument of accusing of Goodwife Nurse and her two sisters, I desire to lie in the dust, and to be humbled for it, in that I was a cause, with others, of so sad a calamity to them and their families; for which cause I desire to lie in the dust, and earnestly beg forgiveness of God, and from all those unto whom I have given just cause of sorrow and offense, whose relations were taken away or accused."


title: Rebecca Nurse

text: The Nurse family accepted Ann's apology and were reconciled with her: by contrast, they never forgave Samuel Parris, the village minister, whom they held personally to blame for their bereavement – "none can know what we suffered by the loss of such a mother" – and they did not rest until Parris was removed from office in 1697. In 1711, her children petitioned the government for a reversal of attainer and were granted compensation for Rebecca's wrongful death. In 1712, the Salem Towne church reversed the verdict of excommunication it had passed on her: "that it be no longer a reproach to her memory or an occasion of grief to her children".


title: Rebecca Nurse

text: In 1892, the community erected a second monument recognizing the 40 neighbors, led by Israel and Elizabeth (Hathorne) Porter, who took the risk of publicly supporting Nurse by signing a petition to the court on her behalf in 1692. One signer was General Israel Putnam's father.


title: Rebecca Nurse

text: The Nurse family remained in the home for many generations. Eventually the Nurse family homestead was sold to Phineas Putnam, a cousin of Rebecca's great-great grandson Benjamin, in 1784. The Putnam family remained until about 1905. By 1909 the farm was saved by volunteers and turned into a historic house museum that includes the original house and cemetery, on 27 of the original of land.


title: Rebecca Nurse

text: In 2021, the 400th anniversary of Nurse's birth, the first full biography of her life was published, Daniel A. Gagnon's "A Salem Witch: The Trial, Execution, and Exoneration of Rebecca Nurse".


title: Rebecca Nurse

text: Nurse's trial was featured in an episode of the CBS radio program "CBS Is There," which aired on July 28, 1947.


title: Rebecca Nurse

text: Rebecca Nurse is a central character in Arthur Miller's play "The Crucible." In the original Broadway production in 1953 she was played by Jean Adair, who died shortly afterwards. This work was adapted for films in 1957 and 1996; Nurse was portrayed by actresses Marguerite Coutan-Lambert and Elizabeth Lawrence, respectively. In the first and much acclaimed television adaption by the BBC in 1980 she was played by Ann Dyson.


title: Rebecca Nurse

text: She is likewise a major character in Robert Ward’s Pulitzer Prize-winning operatic adaptation of Miller's play.


title: Rebecca Nurse

text: She inspired other dramatic treatments of the Salem Witch Trials. The PBS film "Three Sovereigns For Sarah" features Vanessa Redgrave as one of Rebecca Nurse's sisters, Sarah Cloyce; although accused, she escaped execution. The film depicts Nurse and her family members as the main characters. Rebecca was portrayed by actress Shirley MacLaine in the 2002 CBS miniseries, "Salem Witch Trials". Nurse was the subject of "Lectures on Witchcraft" by Charles W. Upham. She is also mentioned in passing in Robin Cook's suspense novel "Acceptable Risk." A fictional character believes her to be pious and registers surprise when seeing Nurse on her way to her execution.. Nurse can also be found as a supporting character in Katherine Howe's historical fiction, The Physick Book of Deliverance Dane. In Howe's novel, Nurse is used as a character foil for the main character, Deliverance Dane. Rebecca's main appearances and dialogue can be found during the scenes of the sentencing and execution of those accused of witchcraft.


title: Rebecca Nurse

text: Rebecca Nurse is the ancestor of several notable people, including Mitt Romney, Zach Braff, and Lucille Ball.


title: Rebecca Nurse

text: Gagnon, Daniel A., "A Salem Witch: The Trial, Execution, and Exoneration of Rebecca Nurse". Yardley, PA: Westholme, 2021.


title: Rebecca Nurse

text: Upham, Charles (1980). "Salem Witchcraft." New York: Frederick Ungar Publishing Co., 2 vv., v. 1 p. 80, v. 2 pp. 56–71, 111, 136, 268, 270–89, 290, 292, 480, 483.


title: Texture mapping

text: Texture mapping is a method for mapping a texture on a computer-generated graphic. Texture here can be high frequency detail, surface texture, or color.


title: Texture mapping

text: Texture mapping originally referred to diffuse mapping, a method that simply mapped pixels from a texture to a 3D surface ("wrapping" the image around the object). In recent decades, the advent of multi-pass rendering, multitexturing, mipmaps, and more complex mappings such as height mapping, bump mapping, normal mapping, displacement mapping, reflection mapping, specular mapping, occlusion mapping, and many other variations on the technique (controlled by a materials system) have made it possible to simulate near-photorealism in real time by vastly reducing the number of polygons and lighting calculations needed to construct a realistic and functional 3D scene.


title: Texture mapping

text: A is an image applied (mapped) to the surface of a shape or polygon. This may be a bitmap image or a procedural texture. They may be stored in common image file formats, referenced by 3d model formats or material definitions, and assembled into resource bundles.


title: Texture mapping

text: They may have 1-3 dimensions, although 2 dimensions are most common for visible surfaces. For use with modern hardware, texture map data may be stored in swizzled or tiled orderings to improve cache coherency. Rendering APIs typically manage texture map resources (which may be located in device memory) as buffers or surfaces, and may allow 'render to texture' for additional effects such as post processing or environment mapping.


title: Texture mapping

text: They usually contain RGB color data (either stored as direct color, compressed formats, or indexed color), and sometimes an additional channel for alpha blending (RGBA) especially for billboards and "decal" overlay textures. It is possible to use the alpha channel (which may be convenient to store in formats parsed by hardware) for other uses such as specularity.


title: Texture mapping

text: Multiple texture maps (or channels) may be combined for control over specularity, normals, displacement, or subsurface scattering e.g. for skin rendering.


title: Texture mapping

text: Multiple texture images may be combined in texture atlases or array textures to reduce state changes for modern hardware. (They may be considered a modern evolution of tile map graphics). Modern hardware often supports cube map textures with multiple faces for environment mapping.


title: Texture mapping

text: Texture maps may be acquired by scanning/digital photography, designed in image manipulation software such as GIMP, Photoshop, or painted onto 3D surfaces directly in a 3D paint tool such as Mudbox or zbrush.


title: Texture mapping

text: This process is akin to applying patterned paper to a plain white box. Every vertex in a polygon is assigned a texture coordinate (which in the 2d case is also known as UV coordinates).


title: Texture mapping

text: This may be done through explicit assignment of vertex attributes, manually edited in a 3D modelling package through UV unwrapping tools. It is also possible to associate a procedural transformation from 3d space to texture space with the material. This might be accomplished via planar projection or, alternatively, cylindrical or spherical mapping. More complex mappings may consider the distance along a surface to minimize distortion.


title: Texture mapping

text: These coordinates are interpolated across the faces of polygons to sample the texture map during rendering.


title: Texture mapping

text: Textures may be repeated or mirrored to extend a finite rectangular bitmap over a larger area, or they may have a one-to-one unique "injective" mapping from every piece of a surface (which is important for render mapping and light mapping, also known as baking).


title: Texture mapping

text: Texture mapping maps the model surface (or screen space during rasterization) into texture space; in this space, the texture map is visible in its undistorted form. UV unwrapping tools typically provide a view in texture space for manual editing of texture coordinates. Some rendering techniques such as subsurface scattering may be performed approximately by texture-space operations.


title: Texture mapping

text: Multitexturing is the use of more than one texture at a time on a polygon. For instance, a light map texture may be used to light a surface as an alternative to recalculating that lighting every time the surface is rendered. Microtextures or detail textures are used to add higher frequency details, and dirt maps may add weathering and variation; this can greatly reduce the apparent periodicity of repeating textures. Modern graphics may use more than 10 layers, which are combined using shaders, for greater fidelity. Another multitexture technique is bump mapping, which allows a texture to directly control the facing direction of a surface for the purposes of its lighting calculations; it can give a very good appearance of a complex surface (such as tree bark or rough concrete) that takes on lighting detail in addition to the usual detailed coloring. Bump mapping has become popular in recent video games, as graphics hardware has become powerful enough to accommodate it in real-time.


title: Texture mapping

text: The way that samples (e.g. when viewed as pixels on the screen) are calculated from the texels (texture pixels) is governed by texture filtering. The cheapest method is to use the nearest-neighbour interpolation, but bilinear interpolation or trilinear interpolation between mipmaps are two commonly used alternatives which reduce aliasing or jaggies. In the event of a texture coordinate being outside the texture, it is either clamped or wrapped. Anisotropic filtering better eliminates directional artefacts when viewing textures from oblique viewing angles.


title: Texture mapping

text: Texture streaming is a means of using data streams for textures, where each texture is available in two or more different resolutions, as to determine which texture should be loaded into memory and used based on draw distance from the viewer and how much memory is available for textures. Texture streaming allows for rendering engine to use low resolution textures for objects far away from the viewer's camera, and resolve those into more detailed textures, read from a data source, as the point of view nears the objects.


title: Texture mapping

text: As an optimization, it is possible to render detail from a complex, high-resolution model or expensive process (such as global illumination) into a surface texture (possibly on a low-resolution model). "Baking" is also known as render mapping. This technique is most commonly used for light maps, but may also be used to generate normal maps and displacement maps. Some computer games (e.g. Messiah) have used this technique. The original Quake software engine used on-the-fly baking to combine light maps and colour maps ("surface caching").


title: Texture mapping

text: Baking can be used as a form of level of detail generation, where a complex scene with many different elements and materials may be approximated by a "single" element with a "single" texture, which is then algorithmically reduced for lower rendering cost and fewer drawcalls. It is also used to take high-detail models from 3D sculpting software and point cloud scanning and approximate them with meshes more suitable for realtime rendering.


title: Texture mapping

text: Various techniques have evolved in software and hardware implementations. Each offers different trade-offs in precision, versatility and performance.


title: Texture mapping

text: Some hardware systems e.g. Sega Saturn and the NV1 traverse texture coordinates directly, interpolating the projected position in screen space through texture space and splatting the texels into a frame buffer. (in the case of the NV1, quadratic interpolation was used allowing curved rendering). Sega provided tools for baking suitable per-quad texture tiles from UV mapped models.


title: Texture mapping

text: Forward texture mapping may also sometimes produce more natural looking results than affine texture mapping if the primitives are aligned with prominent texture directions (e.g. road markings or layers of bricks). This provides a limited form of perspective correction. However, perspective distortion is still visible for primitives near the camera (e.g. the Saturn port of "Sega Rally" exhibited texture-squashing artifacts as nearby polygons were near clipped without UV coordinates).


title: Texture mapping

text: This technique is not used in modern hardware because UV coordinates have proved more versatile for modelling and more consistent for clipping.


title: Texture mapping

text: Most approaches use inverse texture mapping, which traverses the rendering primitives in screen space whilst interpolating texture coordinates for sampling. This interpolation may be "affine" or "perspective correct". One advantage is that each output pixel is guaranteed to only be traversed once; generally the source texture map data is stored in some lower bit-depth or compressed form whilst the frame buffer uses a higher bit-depth. Another is greater versatility for UV mapping. A texture cache becomes important for buffering reads, since the memory access pattern in texture space is more complex.


title: Texture mapping

text: Affine texture mapping linearly interpolates texture coordinates across a surface, and so is the fastest form of texture mapping. Some software and hardware (such as the original PlayStation) project vertices in 3D space onto the screen during rendering and linearly interpolate the texture coordinates "in screen space" between them ("inverse texture mapping"). This may be done by incrementing fixed point UV coordinates, or by an incremental error algorithm akin to Bresenham's line algorithm.


title: Texture mapping

text: In contrast to perpendicular polygons, this leads to noticeable distortion with perspective transformations (see figure: the checker box texture appears bent), especially as primitives near the camera. Such distortion may be reduced with the subdivision of the polygon into smaller ones.


title: Texture mapping

text: Perspective correct texturing accounts for the vertices' positions in 3D space, rather than simply interpolating coordinates in 2D screen space. This achieves the correct visual effect but it is more expensive to calculate.


title: Texture mapping

text: To perform perspective correction of the texture coordinates formula_1 and formula_2, with formula_3 being the depth component from the viewer's point of view, we can take advantage of the fact that the values formula_4, formula_5, and formula_6 are linear in screen space across the surface being textured. In contrast, the original formula_3, formula_1 and formula_2, before the division, are not linear across the surface in screen space. We can therefore linearly interpolate these reciprocals across the surface, computing corrected values at each pixel, to result in a perspective correct texture mapping.


title: Texture mapping

text: To do this, we first calculate the reciprocals at each vertex of our geometry (3 points for a triangle). For vertex formula_10 we have formula_11. Then, we linearly interpolate these reciprocals between the formula_10 vertices (e.g., using Barycentric Coordinates), resulting in interpolated values across the surface. At a given point, this yields the interpolated formula_13, and formula_14. Note that this formula_13 cannot be yet used as our texture coordinates as our division by formula_3 altered their coordinate system.


title: Texture mapping

text: To correct back to the formula_17 space we first calculate the corrected formula_3 by again taking the reciprocal formula_19. Then we use this to correct our formula_13: formula_21 and formula_22.


title: Texture mapping

text: This correction makes it so that in parts of the polygon that are closer to the viewer the difference from pixel to pixel between texture coordinates is smaller (stretching the texture wider) and in parts that are farther away this difference is larger (compressing the texture).


title: Texture mapping

text: Various techniques have evolved for rendering texture mapped geometry into images with different quality/precision tradeoffs, which can be applied to both software and hardware.


title: Texture mapping

text: Classic software texture mappers generally did only simple mapping with at most one lighting effect (typically applied through a lookup table), and the perspective correctness was about 16 times more expensive.


title: Texture mapping

text: The "Doom engine" restricted the world to vertical walls and horizontal floors/ceilings, with a camera that could only rotate about the vertical axis. This meant the walls would be a constant depth coordinate along a vertical line and the floors/ceilings would have a constant depth along a horizontal line. A fast affine mapping could be used along those lines because it would be correct. Some later renderers of this era simulated a small amount of camera pitch with shearing which allowed the appearance of greater freedom whilst using the same rendering technique.


title: Texture mapping

text: Some engines were able to render texture mapped Heightmaps (e.g. Nova Logic's Voxel Space, and the engine for Outcast) via Bresenham-like incremental algorithms, producing the appearance of a texture mapped landscape without the use of traditional geometric primitives.


title: Texture mapping

text: Every triangle can be further subdivided into groups of about 16 pixels in order to achieve two goals. First, keeping the arithmetic mill busy at all times. Second, producing faster arithmetic results.


title: Texture mapping

text: For perspective texture mapping without hardware support, a triangle is broken down into smaller triangles for rendering and affine mapping is used on them. The reason this technique works is that the distortion of affine mapping becomes much less noticeable on smaller polygons. The Sony PlayStation made extensive use of this because it only supported affine mapping in hardware but had a relatively high triangle throughput compared to its peers.


title: Texture mapping

text: Software renderers generally preferred screen subdivision because it has less overhead. Additionally, they try to do linear interpolation along a line of pixels to simplify the set-up (compared to 2d affine interpolation) and thus again the overhead (also affine texture-mapping does not fit into the low number of registers of the x86 CPU; the 68000 or any RISC is much more suited).


title: Texture mapping

text: A different approach was taken for "Quake", which would calculate perspective correct coordinates only once every 16 pixels of a scanline and linearly interpolate between them, effectively running at the speed of linear interpolation because the perspective correct calculation runs in parallel on the co-processor. The polygons are rendered independently, hence it may be possible to switch between spans and columns or diagonal directions depending on the orientation of the polygon normal to achieve a more constant z but the effort seems not to be worth it.


title: Texture mapping

text: Another technique was approximating the perspective with a faster calculation, such as a polynomial. Still another technique uses 1/z value of the last two drawn pixels to linearly extrapolate the next value. The division is then done starting from those values so that only a small remainder has to be divided but the amount of bookkeeping makes this method too slow on most systems.


title: Texture mapping

text: Finally, the Build engine extended the constant distance trick used for Doom by finding the line of constant distance for arbitrary polygons and rendering along it.


title: Texture mapping

text: Texture mapping hardware was originally developed for simulation (e.g. as implemented in the Evans and Sutherland ESIG image generators), and professional graphics workstations such as Silicon Graphics, broadcast digital video effects machines such as the Ampex ADO and later appeared in Arcade cabinets, consumer video game consoles, and PC video cards in the mid 1990s. In flight simulation, texture mapping provided important motion cues.


title: Texture mapping

text: Modern graphics processing units (GPUs) provide specialised fixed function units called "texture samplers", or "texture mapping units", to perform texture mapping, usually with trilinear filtering or better multi-tap anisotropic filtering and hardware for decoding specific formats such as DXTn. As of 2016, texture mapping hardware is ubiquitous as most SOCs contain a suitable GPU.


title: Texture mapping

text: Some hardware combines texture mapping with hidden-surface determination in tile based deferred rendering or scanline rendering; such systems only fetch the visible texels at the expense of using greater workspace for transformed vertices. Most systems have settled on the Z-buffering approach, which can still reduce the texture mapping workload with front-to-back sorting.


title: Texture mapping

text: Beyond 3D rendering, the availability of texture mapping hardware has inspired its use for accelerating other tasks:


title: Texture mapping

text: It is possible to use texture mapping hardware to accelerate both the reconstruction of voxel data sets from tomographic scans, and to visualize the results


title: Texture mapping

text: Many user interfaces use texture mapping to accelerate animated transitions of screen elements, e.g. Exposé in Mac OS X.


title: Jaya Ahsan

text: Jaya Maswood (born 1 July), commonly known as Jaya Ahsan, is a Bangladeshi actress and producer. Starting her career as a model and, later, as a television actress, she currently works mostly in Bangladeshi and Indian Bengali films. She won Bangladesh National Film Award for Best Actress five times for her performances in the films "Guerrilla" (2011), "Chorabali" (2012), "Zero Degree" (2015), "Debi" (2018) and "" (2021). At the Madrid International Film Festival 2020, she won Filmfare Awards Bangla in 2017, 2021 & 2022 and Zee Cine awards in 2018.


title: Jaya Ahsan

text: Ahsan was born to A. S. Maswood (d. 2012) and Rehana Maswood in Dhaka, Bangladesh. She has a younger sister and brother. Along with her formal education, she took a diploma course in Rabindra Sangeet and training in classical music. She first appeared on television when she performed in the teledrama "Panchami". She modeled for a calendar which caught the eye of Afzal Hossain, who later offered her work on a promotional advertisement for the soft drink Coca-Cola. Afterwards, she left modeling and continued with her studies. She joined the newspaper "Bhorer Kagoj", a national daily. After a brief stint at a children's school, she returned to modelling. Thereafter, she worked in Giasuddin Selim's "Shongshoy". She also practices crafting and painting, which she demonstrated in art house productions like "Enechhi Shurjer Hashi".


title: Jaya Ahsan

text: Ahsan first appeared on television in an ad for Coca-Cola in 1997. She debuted her acting career on television through the drama "Panchomi", written by Shahidul Haque Khan.