Item Number – SCP-063 Object Class – SAFE Special Containment Procedures – SCP-063 is to be kept at all times within Dr. R. R. Personal Bathroom, located within the personnel quarters upon Site-19. Object is to be used as designed at least once in a 24-hour period, or the object will begin to emit an unknown specialized radiation that results in objects and material within a 0.6-meter or 2-foot radius being slowly warped and eventually disintegrating into a fine dust. Radiation's effect on living test subjects has not been monitored. Description – SCP-063 appears to be an average pale blue toothbrush. Stenciled along the side of the object are the words, the world's best toothbrush, sick. The word toothbrush is spelled incorrectly, though whether this was accidental or a purposeful action by the creators of the object is unknown. SCP-063 displays the ability to effortlessly cleave through any and all dead or inorganic matter, the focal point of this ability being the bristles. However, matter touched by the bristles is not separated, such as by way of a knife, but completely expunged from existence, leaving no trace whatsoever. This mode of operation is reminiscent of SCP-2207, suggesting that two anomalies share a connection, or were created by the same entity or entities. Additionally, subjects who have used SCP-063 have claimed that the experience left their teeth feeling remarkably clean. In spite of its extraordinary abilities, lab analysis has discerned that SCP-063 is completely made of common plastic. Addendum – SCP-063 was originally found in St. Petersburg, on the person of a thief working in the area using SCP-063's abilities to crack safes. When questioned about the object, subject professed ignorance, claiming that he simply found the object one day.  His reason for doing this is, as of yet, unknown. Item Number – SCP-091 Object Class – Safe Special Containment Procedures – SCP-091 is to be stored in a standard containment locker at Site B. When SCP-091 is not being tested, it is to be placed under combination lock. Since SCP-091 has shown no signs of resistance to tearing or damage greater than that of normal cardboard, great care should be taken when transporting it to and from testing sites. During testing, no one other than the subject should view SCP-091. Though suspected of having seen SCP-091 or to be administered Class B amnestics immediately, and all personal recordings or images in the possession of the subject, both print and digital, are to be destroyed to prevent recurrence. Description – SCP-091 is a Scotty's brand tissue box, currently empty. Immediately upon observing SCP-091, viewers report an overwhelming sense of nostalgia. Those affected begin reminiscing about times they were near SCP-091, major events that occurred while it was present, or people in places that somehow relate to it. SCP-091 was originally recorded as an anomalous item and sent to Reliquary Site 44 until one of the members of the recovery team, Assistant Researcher, while viewing a recording of her wedding from 1991, noted SCP-091 in the background of the film and noted a strong flood of nostalgic memories attached to it, including memories of SCP-091 at the wedding itself, memories of SCP-091 at the reception, memories of SCP-091 during the honeymoon. A further interview with Assistant Researcher Wrozeck's ex-husband demonstrated that he too remembered SCP-091 in all those places and situations, again noting strong feelings of nostalgia and fondness for it. Further investigation found that several people who attended the wedding remember SCP-091 being there and the emotional effect. Others were asked to describe the wedding itself without being informed of SCP-091. In these cases, they described the scene without including SCP-091 until they were questioned about it directly. At that time, they immediately underwent the same previously observed effect. Continue testing under other situations has continued to produce similar results. Administration of amnestics has proven ineffective at stopping the effect if the subject is allowed to view an image or recording of SCP-091. Of note is the fact that in each recorded instance of SCP-091, the box pictured is full of tissues. Item number SCP-101 Object Class Euclid Special Containment Procedures SCP-101 is currently stored in the Subbasement 02 of Site-19 inside of a standard fireproof document lock box within a reinforced concrete room of standard facility size. Said room has been fitted externally with a standard double-door airlock and internally fitted with appropriate safety response equipment as well as biological response equipment. Only personnel of level three are permitted to enter the SCP-101 holding room. Personnel of level two or lower are permitted to interact with SCP-101 only with directives from level three or higher personnel or with standing directives. The airlock for SCP-101 is set to a standard ten minute cycle, during which standard screening scans for biological or environmental hazards will be made. SCP-101 is under standing directives for use during 0600 hours. Outside of the airlock of the holding room for SCP-101, two level two guards are to be posted at all times with overlapping shifts. Description SCP-101 appears as a satchel or bag of intermittent size with observations ranging from an opening of 15 centimeters in diameter to 70 centimeters in diameter. The depth of the container has varied with no standard mean of equality to the relative diameter. The primary feature of SCP-101 is what appears to be a semi-humanoid mouth contained within the opening of the bag with a mean standard of 31 centimeters of depth into the container without more than two standard deviations of variance regardless of the apparent external depth of the container. The mouth consists of 32 teeth of an off-white hue, all of equal shape and size, consisting solely of incisors of approximately 10 centimeters in length. It has been observed, albeit not measured with accuracy, that within the mouth there is a tongue of indeterminate length with observations ranging from 50 centimeters to 3.5 meters. The mouth appears wet and spongy. However, all attempts at removal of possible fluids have resulted in failure with damage to the instruments and harm to the personnel. The current decision is that SCP-101 may be part of a larger entity of extra-dimensional origin. SCP-101 is not externally mobile. However, internal movements within the container can affect minor movements of the exterior of the container that consists of SCP-101's covering. It is understood that due to the nature of the size and probabilities of the container and object within, the object is of extra-dimensional interaction if not origin. SCP-101 has exhibited polymorphic abilities as well as a low level of sentience. The photo on file depicts the item as it was discovered in 1979 in a remote area of the Cascade Mountains in the Pacific Northwest of the United States. Found along with SCP-101 was the decayed remains of a human, clad in a weathered black suit, seated upon an also weathered parachute, missing the right arm up to the joint of the shoulder, which appeared to have bite marks through the remaining bones, assumed to have been inflicted by SCP-101. Speculation as to the identity of this deceased individual has led researchers to the conclusion that this was one DB Cooper, remains removed for the purposes of concealing the existence of SCP-101. SCP-101 has since changed appearance and shape with the apparent end of enticing a subject into reaching within the container. These appearances have ranged from money satchels, to deli boxes, to crispy cream containers, to candy bags, all of which have an external appearance that is indistinguishable from that of the real containers. It has been proposed by Dr. Pruett that SCP-101 is semi-sentient in its attempts to lower subjects in. At the recommendation of data expunged, SCP-101 is currently in use as a means of refuse disposal for Site-19. SCP-101 has not shown adverse reactions to having foreign matter introduced to it, including but not limited to paper product, sewage, cafeteria refuse, metals, polymers, oils, and other products which are not consumable by any known biological entity. Addendum 1 So far, SCP-101 has not exhibited any abnormal behaviors from the standards observed, nor has SCP-101 emitted any substances, either foreign, extra-dimensional, or abnormal. However, it is the concern of Dr. Pruett that SCP-101 may produce an emission in the future. Addendum 2 Further examination under the direction of Dr. Pruett has determined that SCP-101 is ideal for the disposal of hazardous wastes and byproducts of other SCP-related projects. Said doctor is noted as being opposed to this measure. However, 05-1 has given authorization for the project to continue. Item Number SCP-109 Object Class Euclid Special Containment Procedures SCP-109 is currently located in non-critical storage unit 7 and requires no active monitoring. It should not be removed from the unit except to be transported to a research facility, and then only by personnel with level 3 security clearance or higher. When replacing SCP-109, personnel should ensure that it is firmly closed and that it is placed on the molded pedestal in the upright position. Description SCP-109 is a standard issue United States Army canteen, circa 1899, made of a tin alloy and fitted with a heavy cotton cover and a black leather strap. When opened, the item is seen to be nearly full of water. A seemingly unlimited amount of water can be removed from the container without changing the water level or the item's mass, which remains a constant 3.16 kilograms. Probes of the interior of the container reported an estimated volume of 2.8 liters and a shape consistent with the outside. The water in SCP-109 is of a slightly blue-gray tint, with concentrations of 20 ppm of tin and 170 ppm of other electrolytes. The water remains at a constant temperature of 19 degrees Celsius, but can be heated or cooled when moved to another container. Addendum 109-1 Upon the item's delivery to Site-19, it was given the Object Class of SAFE. As tests were conducted on the item, uncertainty surrounding test results prompted General Warrant to upgrade the Object Class to Euclid. Addendum 109-2 Recently, a request was filed and granted by Dr. Warrant for permission to water an okra plant growing in his office with SCP-109. Staff should be notified that said Dr. uses SCP-109 for this purpose for a small time every Friday. Addendum 109-3 It has come to my attention that new Class D personnel are often dared to empty the bottle. Guards are reminded that they are to discourage such activity and inform them that SCP-109 is bottomless. Chanting Chug, repeatedly, is considered unprofessional. Dr. Klein Additional information Due to the range of tests conducted on SCP-109, this section has been provided to present test results in chronological order. Dates have been withheld for confidentiality. Test-1 Subjects imbibed water from SCP-109 reported that it was very refreshing and, despite the metal content, very tasty. Urine samples from subjects were normal. Test-2 Follow-up tests to Test-1 had subjects dehydrate themselves for one full day before imbibing water from SCP-109. Test remains unfinished as subjects were unable to provide urine samples. Test-3 Subject bathed in water from SCP-109. Subject reported increased energy and a much improved complexion following the bath. Test-4 Streptococcus bacteria cultured in water from SCP-109 thrived and multiplied quickly. Water from SCP-109 administered to subjects suffering from Streptococcal infection killed nearly all bacteria and produced a full recovery within 24 hours. Test-5 Blood substitute created using water from SCP-109, given in transfusion to pedestrian hit by a drunk driver. Subjects showed no maligned symptoms from the transfusion and made a full recovery. Subjects physical therapy concluded six weeks early. Test-6 Water from SCP-109 administered to various plant organisms, all of which remained very healthy and showed no maligned symptoms. One proposition for a test which has been discussed for some time has been one involving a combination of SCP-109 and SCP-402. Due to the risk of losing one or both items or creating a hazardous situation, this test has never been conducted. Test-7 SCP-115 Object Class Safe Special Containment Procedures SCP-115-1 is to be stored in the Secure Vehicle Storage Facility, in SITEMENT, where access is restricted unless accompanied by level 3 personnel or higher. SCP-115-2 is currently being kept in a secure drawer of Dr. Wildman's desk and is not to be used without his explicit approval. Many site staff using SCP-115-2 must return it in a timely manner or face punitive measures. No other special containment procedures are required. Description SCP-115-1 is a toy dump truck, with no identifying markers or labels to identify its original manufacturer. However, unlike regular toy dump trucks, SCP-115-1 weighs as much as the actual vehicle it represents, roughly 90 tons. It is currently unknown how the vehicle weighs this much, as analysis of SCP-115-1's composition reveals that it is made of the same commercial plastic commonly found in similar cheap quality toys. SCP-115-1 is also capable of motorized movement and can function exactly like a normal dump truck, accepting the fact that it is several magnitudes smaller. It is controllable by SCP-115-2, which resembles a heavily modified RC car controller. SCP-115-2 can control SCP-115-1's movements, despite the fact that SCP-115-1 lacks any kind of radio receiver or mechanical parts. SCP-115-2 does not work with any other radio-controlled device, but otherwise functions exactly like a mundane radio controller, even requiring batteries to function properly. Testing has shown that in addition to its abnormal weight, SCP-115-1 also has a similar carrying capacity as its larger counterparts, being able to carry her toe roughly 120 tons of cargo. In addition, SCP-115-1 also apparently needs diesel fuel to run properly. There is a small port in its left side that allows fueling, though it stores and consumes as much fuel as a regular dump truck. How it consumes the diesel fuel, as well as where it is stored are issues currently under study. SCP-115-1 was originally found in a construction site in Riga, where workers attempted to move it, but found the task impossible due to the fact that SCP-115-1 weighs 90 tons. They were forced to use heavy machinery to finally move SCP-115-1 off the construction site and to a nearby town, where it became a local curiosity. Foundation agents discovered SCP-115-1 and found SCP-115-2 at the same construction site. Class A amnestics were distributed among the townspeople in order to cover up SCP-115-1's existence. To anybody using SCP-115-1 for testing, I would like to remind you about Newton's laws. Driving SCP-115-1 recklessly at high speeds is inviting disaster, and we've already had to deal with several destroyed walls and equipment due to improper handling. Dr. Item Number SCP-119 Object Class Euclid Special Containment Procedures SCP-119 is to remain open and unplugged at all times except during testing. The door to the room in which SCP-119 resides is to be locked for all periods, except during experimentation, with the entry codes given only to authorized research and security personnel. An industrial-grade disinfectant will be available nearby at all times, and the inside of SCP-119 is to be heavily disinfected before any testing. The contents of SCP-119 are to be monitored through the viewing window and SCP-119 at all times during testing, and will be stopped immediately should the contents become hostile or otherwise damaging to SCP-119. Description SCP-119 is a Panasonic Microwave Oven. It was initially discovered by an agent who had bought it from a liquidation sale of the assets from Valley Vineyards. It is believed that Valley Vineyards was using the anomalous properties of SCP-119 to rapidly age its products and create expensive vintages. Records show that said company was making under-the-table sales of vintages, dated as far back as 19... many years before the company's inception in 2005. These sales are what led to the lawsuits accusing the company of falsifying product information and other forms of fraud, which eventually caused Valley Vineyards to declare bankruptcy. SCP-119 appears to be a standard model of microwave in all respects, except that the Magnetron unit does not produce microwave radiation. Instead, the magnetron emits a previously unknown type of radiation that accelerates time. The amount of time accelerated is based on the time input given at the start in the power level setting. The time input allows for three digits and there are five power level settings. On power level one, the number of seconds input equals the number of seconds experienced within the microwave. Therefore, an input of 30 seconds would cause the microwave to run for 30 seconds, at the end of which the object will have aged 30 seconds. Each subsequent power level one past one causes an exponential increase in the acceleration of time. At power level two with an input of 30 seconds, the microwave will run for 30 seconds, and the contents will have aged 900 seconds, 15 minutes, or 30 times 30 seconds. At power level five, with an input of 999 seconds, the microwave will run for 999 seconds, and the contents will have aged 31,529,964 years. Experimentation with the other buttons on the microwave have not resulted in any anomalous properties, although they do still function as would be expected from a normal microwave. The minute plus button, for example, adds 60 seconds, and the defrost function prompts the user to open the door and flip the contents periodically. Pressing the minute plus button during operation, however, does not recalculate the adjusted time acceleration, merely causing the contents to age at the pre-calculated rate for another 60 seconds. For example, power level two for 30 seconds would age for 900 seconds, 15 minutes. Input of minute plus would result in the microwave running for 90 seconds, and aging the contents 2,700 seconds, 45 minutes, or 3 times 30 instead of aging the contents for 8100 seconds, 135 minutes, or 90 times 90. SCP-119 can be dismantled, and replacement parts can be substituted for every component except the magnetron. When placing the magnetron in any other microwave, including duplicates of the same model, the magnetron continues to exhibit time acceleration. However, replicating the effects of anything above power level two have failed in every model, except the original microwave in which the magnetron was found. Although SCP-119, like all standard microwave models, will normally only function when the door is closed, during deconstruction it was determined that disabling the closing mechanism allows the device to work while open. Subsequent testing determined that the radiation emitted from SCP-119 has a fallout pattern very similar to the microwave radiation it replaced. However, further experiments operating SCP-119 while open now require the approval of a clearance level 4 personnel. Addendum After subsequent testing, it has been determined that the accelerated time experienced within SCP-119 is not accelerated from the perspective of those being affected, instead causing the occupants to perceive that they are simply staying inside of the microwave for the adjusted duration. Should living creatures be exposed to SCP-119 for extended durations, they could quite quickly die of starvation, as they will require as much sleep and food as they would outside of SCP-119. Therefore, further experimentation with living beings now requires the approval of a clearance level 4 personnel. Furthermore, due to the possibility of microorganisms undergoing accelerated evolution within SCP-119, industrial grade disinfectant has now been added to the containment procedure for SCP-119. Test log for SCP-119. Contents Cup of lukewarm coffee Time input 60 seconds Power level 1 Test results Agent attempted to reheat his coffee. Microwave activated and ran for one minute. Coffee was still cool upon removal. Contents Cup of lukewarm coffee Time input 60 seconds Power level 4 Test results Agent increased power level, assuming the first setting was too weak. Microwave activated and ran for one minute. Upon opening the door, Agent discovered his coffee had grown a thick layer of mold and scum, consistent with the amount that would be expected from leaving a cup of coffee out for five months. At this point, the Agent brought the microwave to the attention of the Foundation. Contents Stopwatch Time input 30 seconds Power level 1, 2, 3, 4, and 5 Test results Series of tests conducted to determine effects of various power levels on time fluctuation. Resulting time on stopwatch was 30 seconds, 15 minutes, 7 hours and 30 minutes, and 99 hours, 99 minutes and 99 seconds. There was no result for the last test, as the battery had died. Subsequent test using a more powerful stopwatch with a larger display resulted in nine days, nine hours, and 281 days and six hours for the last two settings. Contents Rattus norvegicus common lab rat Time input 60 power level 4 Test results Testing had expected the subject to age five months. Upon starting the timer, subject became a blur, barely visible in its rapid movement around the container. At three seconds, subject ceased all movement. At five seconds, subject began rotting rapidly. Testing was halted at 10 seconds, and SCP-119 is cleaned of excrement and remains of subject. Cause of death was determined to be dehydration. Contents Rattus norvegicus common lab rat Small cage with lining External automatic food and water dispenser Filled with five months of food and water Attached to tubes routed through air vent Time input 60 power level 4 Test results Upon starting the timer, subject became a blur, rapidly moving throughout its cage. Both the food and water supplies drained from their containers rapidly. At 60 seconds, subject was found to be dirty due to its uncleaned cage, but otherwise fine. SCP-119 cleaned Examination revealed subject to being poor health due to its living conditions in the uncleaned cage, but with no abnormalities. Contents One liter of water in a shallow glass bowl Temperature in room containing SCP-119 lowered to one degree Celsius Time input 600 power level 5 Test results Time inside SCP-119 intended to be approximately 24.7 years with an initial input of 60 seconds. Test intended to determine the difference of atmosphere and heat transfer between the inside and outside of SCP-119, as demonstrated by the evaporation of water at near freezing temperatures. The research assistant entering the time added an extra zero, which would bring the total time up to 2,465,753 years, or over 4,000 years a second. Upon pressing start, an immense amount of air began to cycle through the vent. The assistant immediately recognized his mistake and opened the door to stop the timer, at which point a wave of bluish spores emitted from SCP-119 and onto the assistant. The assistant began to choke and quickly asphyxiated. Subsequent testing on atmospheric conditions revealed low oxygen and high carbon dioxide levels, as well as elevated levels of sulfur. The spores were found to be an unknown Xerophilic species of mold. Within SCP-119 was a dense ecosystem of molds and tardigrades, water bears, along with numerous other unknown species, some of which do not neatly fit within existing categories. The entire ecosystem has created a balanced atmosphere and seems to have stemmed from the original contents of the water, air, and the assistant. In light of this test, containment procedures have been updated to include industrial disinfectant, contents, none. Door is removed from microwave for the duration of this experiment. SCP-119 placed in the middle of a large Faraday cage room with freshly painted floor, using paint that changes colors as it dries. Time input, 30, power level, 3, test results. SCP-119 remotely activated, and all testing observed remotely. Result in paint pattern demonstrated the fall off of radiation from the microwave. The paint closest to the front of the door demonstrating 8 hours of drying, and the furthest section of the floor behind the microwave demonstrated closer to 2 hours of drying. Contents, none. Door is removed from microwave for the duration of this experiment. SCP-119 is placed in the middle of a large Faraday cage room with dried paint. Lightweight floating debris and dust is released into the room through a vent. Time input, 30, power level, 3, test results. SCP-119 is remotely activated, and all testing observed remotely. A pattern of complex air currents reflecting the pattern left by the paint emerges, as individual particles float between stronger and weaker radiation. The radiation did not actually apply any force to the particles, but rather affected their momentum in relation to each other, eventually evolving into a detectable air current pattern. Contents, SCP-442. Time input, 90, power level, 5, test results. SCP-442 continued to keep the correct time during the entire duration, showing 1 minute and 30 seconds of time passing over the course of the experiment. Contents, SCP-289. Time input, 90, power level, 5, test results. None. Permission to carry out experiment denied. Not funny. Do we really need to explain why that is a bad idea? You already know exactly what that would do. 05. Contents, Bottle of Macallan 12-Year Scotch. Time input, 60, power level, 5, test results. During previous tests, researchers had been joking that they should nuke themselves a drink, and one researcher retrieved a bottle of Macallan from his quarters. The 12-year vintage is relatively inexpensive to obtain, but the 25- and 30-year vintages are considered by some to be the best of all scotch commercially available. Upon completion of tests, bottle was effectively a 37-year vintage. Intention of tests had been to consume during subsequent tests, but at this point the intent had been heard by a superior, who allowed the researchers to keep the bottle as long as they waited until off-duty to consume it. Subsequent testing determined that the results of this experiment were delicious. Dr. Grant. It would seem Dr. Grant is a rather poor whiskey connoisseur, as whiskey does not age outside of the barrel. Your delicious experiment resulted in a 37-year-old bottle of 12-year aged scotch. Well done. Dr. Darrell. I stand by my initial assessment. Delicious. Dr. Grant. Item Number SCP-145 Object Class Euclid Special Containment Procedures SCP-145 is to remain inside its room at all times, in a 0.5 meter by 0.5 meter by 0.5 meter plexiglass container, unless being studied. Room is to be thoroughly sound-proofed and securely locked when studies of SCP-145 are not in progress. Under no circumstances shall any personnel come into physical contact with SCP-145 without being accompanied and constantly observed by one or more other personnel, unless conducting testing with proper authorization. Any personnel showing signs of intense psychological trauma must be immediately escorted out of the containment area. Depending on the level of trauma of affected personnel, they may be required to submit to consultation with an approved psychiatrist for no less than two weeks. Description SCP-145 appears to be a standard 2002 model cordless telephone handset of Alcatel brand on its standard-issue charging base. The charging base appears defaced. All jack inputs are sealed with resin glue and the power input to the device has been gouged out with an unknown sharp tool. Serial number and production date are unavailable, as all labels and stickers have been ripped off or defaced. The phone rings constantly, whether it is on the base or not, regardless of the lack of power source. Tests have shown that the battery is removable and disassembly of the base has not shown any effect on the hand unit. The hand unit itself has had all of the seams sealed, preventing conventional disassembly. When answered, a female voice speaks on the phone in a voice that shows high levels of stress. This voice varies from conversation to conversation, but in all cases, the voice expresses extreme panic and proceeds to plead with the listener for assistance, as she describes instances of torture conducted on unknown victims. In the background, the listener will hear sounds of violence and expressions of pain and anguish. Audio analysis has so far indicated several individual voices over disparate calls. The methods of torture implied thus far, judging from the phrases and reactions of those speaking at the time of contact, have included branding, electrocution, laceration, sexual assault, data expunged, and dismemberment. The callers appear to be non-automated and entirely sentient. Attempts to trace the call are tracked down the location of the tortured callers have proven unsuccessful thus far. Attempts to block the signal of the phone with the use of a Faraday cage have also been unsuccessful. Research is conducted in teams of at least three, one Class D staff, one Class 2 slash 145 audio technician, and one Class 3 security staff, with only Class D staff permitted to have direct auditory contact with SCP-145's transmissions. Testing has shown that in 100% of cases, a subject answering SCP-145 without live supervision will vanish without any indications of transportation methods. Video recording devices do not show the method of transport. The subject will be present in one frame and absent in the next. In case of disappearance, the phone will simply fall to the floor. The phone does not appear to have sustained damage from any of these falls thus far. Subsequent communication with the object has revealed that vanished subjects join the group of torture victims. Testing log. Testing procedure. All tests will be conducted with D-Class personnel. Any issued equipment for the test must be recorded in the log. The D-Class personnel will then be ordered to pick up the phone. After disappearance of initial test subject, the above standard research team will answer the phone and record any observations. Test 145A. Date. Undisclosed. Subject. D-1453749 issued one GPS locator device. Testing to attempt to ascertain the location described at the other end of the line. Result. GPS rendered non-functional after disappearance of D-Class personnel. On following interaction with SCP-145, audio technician identifies voice of D-1453749 as joined other victims. Test 145B. Date. Undisclosed. Subject. D-1454751 issued one GPS locator device. One six-inch standard-issue military combat knife. Second attempt to ascertain the location described at the other end of the line. Self-defense option provided to subject. Result. GPS rendered non-functional after disappearance of D-Class personnel. On following interaction with SCP-145, female voice indicates continued stress and states, oh god he's cutting him. He's cutting off data expunged. Audio technician then identifies voice of D-1454751 as joined other victims. Test 145C. Date. Undisclosed. Subject. D-1455319 issued one 9mm semi-automatic pistol. One Kevlar vest. Subject compelled to pick up phone. Attempt to determine interactivity of location. Determine if any self-defense method is possible. Result. On following interaction with SCP-145, gunshots are heard. Then data expunged. Female voice resumes. States data expunged. And additional gunshots are heard. Audio technician identifies D-1455319 exclamations of pain after each gunshot. Test 145D. Date. Undisclosed. Subject. D-1456842 issued one kilogram of C-4 explosive. Concealed in supply kit. Explosive attached to remote trigger with 30 second delay. Triggered before interaction with SCP-145. Attempt to determine any possible level of interaction or destruction of location. Result. Data expunged. Resulted in several members of Foundation personnel missing. Including Dr. R- And all researchers associated with data expunged. Breaches of SCP security at sight. Further testing of this nature suspended at this time. I don't know who thought this might be a good idea. I know sometimes we let sympathy get the better of us. But this attempt to bring relief to SCP-145's victims just cost the Foundation a lot of money and resources. Dr. R- Item number. SCP-154. Object class. Euclid. Special containment procedures. SCP-154 is to be kept within Weapon Locker 8. In armed research Site 47. Personnel wishing to research or use item must submit the required request forms. Anyone attempting to remove the item without clearance or from outside the facility is to be terminated on site. Description. SCP-154 is a pair of simple bronze bracelets.  Spectrograph analysis has proven that the item is composed entirely of copper, 85%, tin, 11%, arsenic, 3% and traces of other slight impurities. Less than 1%. When both bracelets are worn on the same arm and the wearer concentrates on them with arms extended in a depiction of a traditional knocked bowstring pose. Achieved by having the arm with the bracelets completely extended in front of one's self with the opposing arm extended up to the elbow of the fully extended arm. A large indistinct incorporeal bow will form in the extended hand and both bracelets will glow slightly. From that point onwards SCP-154 can be treated as a bow until the pose or concentration is broken which results in the bracelets reverting to normal. There is no actual bowstring but completing the motion of pulling it achieves the same effect. When the bowstring is pulled and released the bones of the arm will be forcibly ejected from the extended limb traveling in a straight path at speeds recorded over 300 meters per second. The missing bones and resulting damage to the arm are quickly regenerated and the weapon is capable of being fired again within minutes. Tests using subjects possessing multiple arms and hands such as SCP-1884-B have demonstrated the ability to fire SCP-154 several times with the bones of different arms being used with each successive firing. The regeneration implemented by the item is limited only affecting the damage inflicted by the weapon itself. This regeneration seems to be in automatic action and will continue in almost all situations. Both firing the weapon and the resulting regeneration are understandably painful and participants which have used the item once are generally disinclined to repeat usage. However, there have been found to be some occasional abnormalities regarding the regeneration. Most often this manifests simply as minor mutations of the original subject such as changes in size, pigmentation, and structure of the original organelles. These are an uncommon occurrence capable of happening during any use of the weapon, though generally tend to occur during repeat usage. There are more drastic abnormalities, though these are much rarer and coincide with highly frequent use. These mutations can range from anything such as the growth of extra joints and digits in the affected arm to a complete change of the chemical or physical structure of the limb. One test subject unknowingly had the bone matter within his arm converted into an unstable explosive compound, only discovering the fact when it detonated, causing two fatalities and three casualties. Another had the entire bone and musculature structure morphed into fully functional serpentine physiology. Item number SCP-160 Object Class Euclid Special Containment Procedures SCP-160 is kept in a secure biocontainment chamber at Scythe SCP-160 is to be fed live prey in the form of a rabbit or other animal of similar mass once per week, with feeding to be performed via automated delivery system only. Experimentation with SCP-160 may only be performed with prior permission from at least two level three personnel, and any personnel entering the chamber must wear an armored suit at all times. Description SCP-160 appears to be a quadraflyer unmanned aerial vehicle or UAV with a diameter of approximately 1.1 meters at its widest point, similar to the model manufactured by the corporation. It is devoid of any identifying marks or manufacturing labels, though visual inspection of SCP-160 has revealed signs of scratches and other superficial damage, indicating that prior identifying labels may have been removed. SCP-160 operates continuously and completely autonomous from any identified control source, and exhibits behavior similar to that of predatory birds. It will actively hunt prey such as rodents and other small animals, and upon locating such prey, dive down at high speed and impale its prey with what appears to be a metallic proboscis. Analysis of its prey shows that it then injects a highly caustic substance that liquefies the internal organs and extracts the resulting slurry. SCP-160 will generally avoid humans and larger animals, but has been recorded using its proboscis in self-defense. Injuries inflicted by SCP-160 are extremely painful and can cause death via liquefaction of vital organs or internal bleeding. Further research on SCP-160 is underway, but has proven difficult due to SCP-160's continuous operation. Tranquilizer darts are ineffective, as SCP-160 appears to be entirely composed of non-biological components, and requests to attempt a low-intensity electromagnetic pulse to disable it have been rejected due to possible unforeseen damage. SCP-160 was discovered by Foundation agents in 2000 following multiple reports of household pets from the town of Data Expunged, disappearing and subsequently being found dead under unusual circumstances. SCP-160 was quickly identified and lured into a transport vehicle by a containment team and subsequently taken to site. A search of the area turned up several desiccated small animals, including house cats, rabbits, wild rodents, and miniature dogs. Item number SCP-161, Object Class, Euclid. Special containment procedures. All three instances of SCP-161 are to be kept in separate containers in containment locker 34 Zeta. Each container is to be triple locked, with all nine keys to go to separate members of the senior staff. Once every three months, each individual instance of SCP-161 is to be removed from containment. Current scheduling allows for only one instance to be removed in any given month. When removing SCP-161, the remover is required to not be a member of senior staff. However, they are to be accompanied by the three members of senior staff with the keys, at all times that SCP-161 is out of containment. The remover is to be dressed in a full environmental suit, with extra reinforcement around the wrist joints, to avoid contact. The senior staff accompanying the remover are to be dressed similarly. Before removal, a cell is to be set up for activation of SCP-161. Two D-class will need to be requisitioned. One D-class is to be strapped into a chair, immobilized, their left arm at a right angle to their body. It is imperative that their wrist be locked in, so that they cannot turn their hand or move the angle of SCP-161. The second D-class is to be strapped to the wall directly in front of the first D-class's hand. When removed, SCP-161 is to be immediately moved to the prepared room. SCP-161 is to be placed into the locked hand of the immobilized D-class. Once the D-class has activated SCP-161 once, it is to be removed from them and returned to containment. Both Class D are then to be returned to general populace, but are never to be assigned together. Description There are currently three copies of SCP-161 in Foundation Control. SCP-161 appears to be a brightly colored plastic child's pinwheel, with a The Factory stamp on the back. SCP-161 only displays its unique properties when held in the bare hand of a human being. Approximately three to seven seconds after grasping SCP-161, the holder will find himself made aware of how to activate the device. From this point on, the holder is completely convinced that SCP-161 is capable of emitting energy pulses of varying strength. This conviction only affects the bearer, as no one else can see these pulses, nor do they appear to do any actual damage. However, anything the wielder destroys with these energy pulses becomes no longer capable of affecting the wielder, even when no longer in contact with SCP-161. Walls affected by the energy pulse can be walked through by the wielder, and living beings so affected not only cannot touch the user, but anything wielded by said beings will be unable to touch the user of SCP-161 as well. A minor side effect causes the wielder of SCP-161 to develop megalomania and delusions of grandeur. Addendum 1. Original procedures altered when a security guard with no prior knowledge of SCP-161 broke into the containment locker and began using it freely. After security contained the breach, researchers discovered that if SCP-161 were not used occasionally, the artifact would begin to radiate a telepathic lure. The lure would affect those with low self-esteem and willpower and call them to SCP-161. At that point, they would take the artifact in hand and begin to use it as described. Addendum 2. A junior researcher attempting to cultivate the approval of senior staff noticed an unusual trend in beings and objects supposedly destroyed by SCP-161. Investigation into beings affected by SCP-161 before containment revealed all of them had committed suicide, many within a year of being affected. A review of objects affected by SCP-161 showed that, while many were still standing, most had fallen apart, and those still together showed signs of decay many years in advance of where they should be. A review of researchers who had been affected by SCP-161 revealed that over 50% of them had since died. Of those that remained, interviews consistently contained the idea that life just wasn't fun anymore. As of this finding, SCP-161 is now exclusively to be used on Class Ds and never near support walls. Use of SCP-161's effect for the acquisition of SCP objects that create an environment hostile to terrestrial life, including SCP-2933, has been proposed by several research staff. Final approval pending. Approval denied. Item number SCP-168. Object Class. Safe. Special Containment Procedures. SCP-168 is to remain in Observation Room 221D of Sector 28. It should be propped at the full angle that its casing allows, facing the unshuttered window provided. The entrance is to remain locked, with entrance available by request. Based on prior research, it is not to be used as a normal calculator would. Discussion with SCP-168 is encouraged, but is to be limited to a maximum of one hour per day. No exceptions. Description. Found resting on a desk during clearance of the condemned elementary school building in 1991, SCP-168 is a Hewlett Packard brand graphing calculator. Model number HP-28C. Upon initial inspection, it was discovered that the name Eric was carved into the inside of the removable casing. However, upon inputting a simple equation, six divided by three, and pressing the equals button, the screen of the device went blank for three minutes and 34 seconds, after which the alternate key function engaged, displaying the message. What time is it? Though not altogether mobile, SCP-168 has displayed signs of action when personnel are not present. It also possesses both vision and hearing, though how these processes work is currently unknown. This evidence has led to petitioning to upgrade the object to Euclid Class, justifying more secure arrangements for containment. Document number 168-1 Interview E-12. Recorded log of dialogue between SCP-168 and Dr. Howard, dated January 14th, 2008. Replies from SCP-168 are to remain capitalized to indicate non-vocal communication and preserve authenticity. SCP-168 is also incapable of forming punctuation marks, safer period, comma, and question mark. Begin log. Dr. Howard, can you hear me? SCP-168? Yes. Dr. Howard, do you have a name? SCP-168. Calculator? Dr. Howard, may I call you 168? SCP-168, I don't see why not. Dr. Howard, good. How long have you been alive, 168? SCP-168, what is alive? Dr. Howard, being able to think. SCP-168, oh. SCP-168 pauses for approximately two minutes. SCP-168, 12 years, three months, 12 days, 8 minutes, 32 seconds. Dr. Howard, why did that take so long? SCP-168, no one's ever asked. Dr. Howard, moving on. There is a name carved into your casing. Who is Eric? SCP-168. Eric was nice. I liked Eric. Where has he gone? Dr. Howard, I don't know where he has gone, 168.  I hope he remembers to come back for me again. Dr. Howard, was Eric your owner? SCP-168, Eric was nice. Dr. Howard, alright. Do you function as a calculator should, 168? SCP-168, I should hope so. Dr. Howard, may I try using you to calculate an equation? Something like 2 plus 2. SCP-168, yes. Dr. Howard enters 2 plus 2 and hits the enter key. The answer 4 appears on SCP-168's screen instantaneously. Dr. Howard, may I try another one without telling you what it is first? SCP-168, yes. Dr. Howard enters 264 divided by 8 and hits the enter key. The answer 33 appears on SCP-168's screen after 12 seconds. Dr. Howard, why did that take so long, 168? SCP-168, long division is hard. Dr. Howard, I think that's enough for today. I'll talk to you again tomorrow, 168. SCP-168, wait. It's dark in here. Can you open the window? Dr. Howard, there is no window in this room, 168. SCP-168, can I have another room with a window in it? Dr. Howard, I'm afraid not. SCP-168, no fair. End log. Document 168-2, report E-18. Upon entering storage room 185D to continue testing with SCP-168, on the morning of January 15th, 2008, I discovered the only table in the room upended, with SCP-168 resting next to it, in an upright position. It's screen red. How do you like that?  Attempts to communicate with SCP-168 after that point were ignored. I suggest that we move it to room 221D, if we want to get anything actually useful out of it. Dr. Howard. Item number, SCP-170, Object Class. Safe. Special containment procedures. SCP-170 presents no danger, and as such can be contained safely in any secure storage locker. However, due to the potential misuse of the substance, as well as the limited quantity of SCP-170 available, no personnel may remove it from storage without prior approval from Dr. Description. SCP-170 appears to be a standard tube of superglue, in a yellow tube 13cm long. There is no manufacturer information or any other text on the outside of the container, apart from the word superglue printed in bold letters on the front. Whenever any amount of the substance is applied to solid material, and that solid is put in contact with any surface, both objects lose molecular cohesion in the area surrounding the contact points, allowing one to be pushed through the other. The effect lasts only moments, however. Within a third of a second of the two surfaces making contact, the ability of each to pass through the other is nullified, leaving both permanently bonded together. SCP-170 was seized, in a raid on an illegal laboratory in in 19 the unusual properties of SCP-170 were unknown, until a standard test on all seized materials was performed on it. A laboratory technician used a pipette to extract a small amount of SCP-170 for analysis. Upon attempting to dispense the substance onto a slide, the pipette immediately passed straight through the slide, which was on a mount. Further tests were run upon the pipette slide, and it was discovered that they were bonded on the molecular level. Upon hearing of this, SCP personnel were dispatched to confiscate all seized materials. Notable tests, test 04, test materials, one heavy duty chain, weights of various sizes. Procedure. A small amount of SCP-170 was applied to the last link of the chain, which was then bonded to the reinforced ceiling of containment area 17F. Weights of various sizes were then hung on the chain to determine the structural falling point of the bond. Results. After approximately 9 metric tons were suspended, the chain finally snapped, but not at the bond point. It snapped at the ninth link from the bottom. All links apart from the one embedded in the ceiling were tested, and showed signs of distortion and stretching. However, the bond point in the ceiling showed no sign of weakness, or separation of chain and ceiling. Test 07, test materials, two identical cubes of 24 karat gold, as close to 100% pure as possible. Procedure. Using robotic arms to ensure perfect alignment, cube 1, the cube with SCP-170 applied, was pushed completely through cube 2, leaving what appeared to be one gold cube equal in size to either of the original cubes. Results. Upon examination of the sole remaining cube, it was found to have a density of 38.6 grams per centimeter cubed, which is precisely twice the density of gold. Even melting the sample did nothing to change this, as the resulting liquid gold also had the same density. This implies that the substances don't displace each other. Every atom is accounted for. Analysis of the atoms has proven that they are regular gold atoms, implying that they don't undergo nuclear fusion to accomplish this increase in density. The atoms are simply packed into a smaller space than the laws of physics would seem to allow. In light of this experiment, Dr. Ruhn has requested permission to use SCP-170 to glue two pieces of uranium together to make a more fissile sample. Due to the obvious safety concerns this poses, this request was denied. Test 12. Test materials. One D-class personnel. One wooden desk. Procedure. First test using live biological subjects. D-class personnel had a small amount of SCP-170 applied to his right index finger and was instructed to poke the desk. Results. Subjects' fingers sank into the desk up to the first knuckle, despite obvious panic. The subject reported no pain, discomfort, or sensation below the bond point. However, his finger quickly began swelling and turned purple, as his circulatory system continued pumping blood to an area that could no longer return it. Finger was amputated between the first and second knuckle. Test 19. Test materials. One Pratt and Whitney F-100 jet engine. The reinforced ceiling of containment area 19B. Procedure. SCP-170 was applied to the jet engine mountings, which were quickly pushed 3.2 cm, or approximately 1.25 inches, into the ceiling of the chamber. After connecting an appropriate fuel supply and control system, the jet engine was fired. Results. The engine was run continuously at high speed for 40 minutes, while cameras monitored the join point for any signs of stress. While small cracks appeared in the concrete around the join point, there were no indications of any possible structural failures or separation of the two materials, even under a force of 120,000 Newtons.


So, the next topic is about the packet switching system. So, this is I will continue from wherever I left last time. So, we want to implement a packet switch and one of the possible options which I thought of is going to have a we will going to have a cross bar. Cross bar will have certain number of inputs and will have certain number of outputs usually they will be same in number. And we are going to assume that packets are coming on each one of these lines and they are all synchronized in time. So, these are these are the packets which have arrived on each one of these. There may be situations that there is no packet on certain line that is also possible. So, what happens? The first slot will come then second slot, third slot that is the input which is coming in inside the switch. We have a interface card setting on each one of these ports. These interface cards will read the packet at least the packet header. Usually every packet will have a header as I have told earlier. So, this is when this access is time. So, it will always will be received first. There is a possibility of a trailer, but we are not bothered about the trailer part. This is not a store in forward. So, we will not do CRC checking in this case. So, if there is a errors happen, this may be misrouted. There is a possibility of even doing CRC checking, but then whole packet has to be received first here. CRC has to be verified and then only the routing will happen. So, there is going to be one slot delay which will happen at interface board in that case. So, usually delay will be for reading of this only header part and then there is some processing time, worst case processing time. This much delay will be required. So, we have to introduce that delay here. I am showing it by loop. This can be a kind of a memory which you can put, but it is going to have a still more a better time granularity or it can be a delay line. It is going to be a fiber optic system. It is going to be easily a delay line. Now, all these interface information, this will be always after the interface card once the header has been analyzed, has been read out. So, these are all through the interface thing. Delay part, that is where the packet will come. Now, this has to all come to the central control processor. This control processor will then decide after doing appropriate computation that which cross points have to be activated. So, these are the cross points. So, cross points will be chosen like this. So, this is going to now do a what is called row and column control thing for this. So, they will be activating just before the slot arrives. So, usually there will be a guard bend time between two packets. So, packet actually is not going to fill up the complete slot. It is going to be only part of it, because you require a guard bend time for the activation of cross point and then another time, guard bend time for again what is called releasing of the cross point and setting up of a new cross point. Guard bend, you call it a GU, because it is in temporal space, it is not in frequency space. In FDM for example, if you have spectrum of various frequency, frequency division multiplexed signals, you always keep some gaps where there is no cross torque. This is also known as guard bend. In fact, this term because this is a frequency bend. So, guard bend looks like, but in time there is nothing like a bend actually. That is a guard time, but you can also call it guard bend time. So, you require a gap between them. That has to be kept when you are designing the system, but usually whenever you do analysis, we assume all these operations can be done at almost infinite space. So, you need not actually have a guard bend. On paper, it is fine theoretically, but in real life, you need to have it actually. That will depend on your circuitry, the time which is required here. What is going to be tolerance is in activating and deactivating the cross points. Remember activation also means you have to first of all do the row and then column and row has to go down and column has to be kept up for one slot period when the cross point is active and column has to go down. So, these just take time. They cannot happen instantaneously. So, as for this, now this packet will be passed down to the output and this scheme is going to work fine so far. Each packet is going to have a separate destination. No two packets will have the same destination. If this condition somehow can be satisfied, then this is going to work fine. This switch is going to work fine. And if you can, this is what is known as, this is a basic simple switch actually, but real life the switch will not work this way. There is always a possibility because the packets which are arriving are coming at there independently at each input port. So, there is a possibility that you will have more than one packet coming in and they want to go to the same destination. In that situation, what has to be done? So, one possibility is that in this kind of scenario is basically what will happen is, if there these two wants to go to for example, this for remaining of them, unique combinations are actually ok. For all of them, they will they are not having any conflict with anybody they are going through. Only these two want to go here, but I cannot pass, I cannot keep these two on. In row, I can actually have multiple cross point active, but not in the column. So, when you have multiple cross point active, this way it is a multicasting. So, since this cannot be done, so what you will do is only one packet will be allowed to go through. Second one will be actually in this case has to be sent to the blank one or you do not activate that cross point actually. So, second one will be read out, but it will not be going anywhere.  It cannot pass through the switch it is lost. So, that could be one strategy. So, we will actually essentially make an estimate of the throughput, maximum throughput which can be achieved in such a scenario ok. How to choose a vector packet? You have to decide an algorithm. If you say I am going to give one a higher priority and two a lower priority, always choose the one. First and drop the two. If all ports are having equal priority, choose anything randomly and let it go. If packets are lost is the higher layer which will take care of it. They have to keep track of the packet loss, I have to do a retransmission. There will be some data link control or flow control mechanism which will be sitting in there. Window flow control will be there which will take care of the retransmission. That is one reason why the packet can get lost. Now, there can be an alternative strategy. We can say, now before actually going to the alternative strategy, I can just quickly make an estimate of what will be the throughput for this particular thing. So, a packet is going to be there on a line is with probability p. So, that is the loading factor basically, utilization factor of every line, every input line. It will have a packet with probability p and there are n lines, n by n which I am assuming. So, this can go to any one of these packet with any one of these lines with equal probability. Usually what will happen again there is a input one and output one are connected to the same node. These are given direction line, but actual links are bi direction. So, it will not be choosing at least the output one. It will always be choosing out of the remaining n minus 1. So, you will have with p this power n minus 1 probability, the packet will be choosing any one of these which actually implies that. Now, if you look at n output, p is the probability that packet is there and then with equal probability it is going to be directed to have any of the outgoing ports except the outgoing port corresponding to itself. Each line, each input line is always paired with an output line because both pair will be connected to a node or another switch always. So, do not send a packet to yourself actually in the loop that is not possible. That I am actually precluding from possibility. So, take an output. So, how many packets will be directed to probability that i packets will be directed to it, I have to estimate that. So, from here you can give the simple combinatorics actually from there you can get it. So, probability that a packet from a line will come to this is given by p divided by n minus 1. It can receive only packets from all other lines except a line which corresponds to itself. This is the same situation you discussed earlier that if 1 is talking to then 2 is also talking to 1. Yes, means you will never send a packet to yourself. But in such a switching we will discover that cross bar when you discuss. Means we never do a looping. So, there I am sending a packet to you are sending it to me that is a different situation. You are sending a packet that may come through a different route all together to me. Each packet is going independently, but when I send a packet to a switch it should not be sent to an outgoing port which is again back connected to me. So, my packet itself will come back to me. In that scenario your voice was not coming back to you it was other persons voice which was coming to you. So, this actually means that i packets will be coming to this particular node in one single slot will be directed what is the probability of that actually. So, that probability will be p divided by n minus 1. So, from remain from out of the n minus 1 possible input i of them will direct it to me this is with this probability. The remaining one of them will not directed to me is this probability n minus 1 minus i and this will happen in combinations of n minus 1 c i. So, that will be this probability of receiving i packets. So, even if you receive anything which is when you will receive no packet in a slot when i is equal to 0. If you receive i is equal to 1 or i is equal to 2 i is equal to 3 you will always get only one packet remaining will be dropped. So, if I sum up all the probabilities which goes from p 1 1 packet received 2 till p n minus 1 I will always get one packet this is a probability of achieving getting at least one packet at the outgoing port. So, outgoing line will have in a time slot with this probability 1 packet there. So, that will be the throughput actually and this is nothing but 1 minus p 0. So, what is p 0 from here we can estimate this will be n minus 1 c 0 this will be nothing but 1. So, I can remove this this is 0. So, this will be 1. So, this is 1 minus p divided n minus 1 n minus 1 under full load condition actually in every slot there is a packet the packets are coming all the time p is equal to 1 then we will make an estimate from there. So, that will be the maximum throughput. So, I can divide by this by p minus p n minus p and this will be nothing but in this in limit when n goes to infinity this will become e raise power minus p. So, I want 1 minus p 0 to be estimated. So, 1 minus e raise power minus p is what is going to be a throughput S per line throughput per line will be this much. So, this will get a maximum value when p is maximum that is a negative term actually remember. So, I have to minimize on that since the exponent is negative. So, I have to maximize over p. So, p gets a maximum value which is. So, from here actually you can plot how the throughput increases with p and this will achieve you can plot this S this is the throughput per line as p goes from 0 to 1. So, e raise power minus p is this. So, this value is 1 over e. So, this is what will be the curve for S. So, when p is 1. So, initially throughput will increase as probability increases but then when p goes to 1 it means full loading condition at the input put that value it is 1 over 1 by e which is going to be I think 0.532. I think this value is 0.532 or something. But this is what you will get as a maximum. So far this policy is fine but I need to improve because there is a maximum throughput limit and I will also have a loss even if p is equal to 1 roughly about more than 40 percent the packet will actually be lost this is not a good switch in that sense. Ideally if I actually have even under high load conditions low load conditions it is fine but under high load conditions I ideally would like to have something which we which is almost 95 percent or 96 percent probability and as less number of packet should be dropped as possible then of course we will be interested in what will be the delay in the packet being transmitted out. So, now let us look at the strategy for buffering.  We have taken at the input and we have assumed fixed slots at all the inputs are synchronized and I am actually neglecting all the delay and everything I am assuming that header can be processed control processor can process almost at infinite speed and can apply the control action. In real life there will be some amount of delay after this header has been detected there will be some guard band which has to be provided between two packet two consecutive packets and two consecutive slots. So, that this action of setting up everything can actually take place packet will only be transmitted when the cross point is connected not when it is under the process of connection. So, based on this various cross points are set and you get the output that was the first thing which we did. Secondly, I thought let me do a very simple analysis there is no buffering here packet just keep on coming whatever comes in the slots we just transmit if there is more than one packet trying to go to one single output we have no option, but to allow only one and rest everything will be dropped. I am not worried about I am actually taking randomly any packet will be selected in going out, but there can be a priority disciplines where you can say if the one and two are going to content packet from one will be given priority and it will go out packet from two will not go out because I remember I have not still estimated the probability that your packet will be lost I am only worried about the throughput part throughput is how many packet per unit slots are going out from an outgoing port. So, whatever is true for one port has to be true for any other port. So, under that assumption then we estimated what is going to the probability of having a packet here from an incoming line. So, the probability p the packets will be there in this slot this will be directed to remaining n minus one with probability one over n minus one equally likely chance uniform routing. There is one doubt. So, the probability of p should be 1 by n because equal probability n lines are there. So, it will be 1 by n or p 1 p by n. p is a arrival probability of having a packet on one single line each line is independent. If you want all the lines to have a packet that probability will be p rest over n only one packet one line has the packet that probability is p all other lines does not have 1 minus p rest over n minus 1. So, in general I packets will be present here that probability will be given by p rest over i and because they can be in any order any combinatorial. So, it is n c i n 1 minus t n minus i that is a probability that i packets will be there in a slot at all the inputs of a switch. So, t is a probability of having a packet on one line the same probability exists for second line also third line also. The case which you are taking it will be 1 by n there is only one packet which is going to come it has to go on any one of these lines then it will become 1 by n, but we are not all inputs are independent they are not dependent on each other. So, once we get a probability that this guy will get a packet from one line say this one. So, that probability is p divided by n minus 1 the input which is corresponding to this output port I am not bothered about that anyway when I take limit n goes to infinity that n minus 1 does not matter you can actually observe that I have used that thing. So, getting i packets from various combinations directed to only this port this probability has to be that i packets have been directed out of n minus 1 which could have come to this port the one which is coming at the corresponding input port corresponding to this output will never come to this. So, that I have excluded. So, n minus 1 c i this is a probability it is been directed here i of them remaining what will happen they have not come to you. So, it has to be 1 minus p by n minus 1 the remaining step simple binomial thing and then of course, we say let us find out what is a probability that no packet will come to me because either you find out each one of them in sum all these or you do 1 minus of p 0 both are actually same. So, we have found out p 0. So, when you put i is equal to 0 this will become 1 this term goes away 1 minus p by n minus 1 will become this I have multiplied divided by in the exponent by minus p and when I take a limit n goes to infinity or n minus 1 goes to infinity this will become nothing but exponential. So, it becomes exponential sorry this limit actually should be put here you will get e raise power minus p. So, what is a probability you will get at least 1 packet remaining will be drop diamond bother, but I will have 1 packet in that slot. So, if I have 1000 packets how many packets will come. So, this will be 1 minus p 0 multiplied by 1000 those many packets per unit slot will be going out. So, I have put that value it becomes 1 minus e raise power minus p of course, e raise power minus p will be shown by the line which is decaying and the growing line is what will be your throughput 1 minus of that. So, as p increases your throughput will increase, but it will saturate it cannot never be higher than this when p is 1 which is 1 over 1 minus e 1 minus 1 over e I think it will be 0.58 or something it must be around that value I think. So, you can compute that and then verify. So, that is a quite large number of packets will not pass through even when p is 1, p is 1 is saturation case when every input is going to have a new incoming packet in every time slot. That is what is p is equal to 1 packet is under full load and the complete saturation you will saturate to this 40 percent of packets will be lost. So, this which we will be happy, but we are going to have very high loss rate I have to minimize on this loss rate that is a question how to do it. So, we have to solve this particular problem. So, I have now moved from simple cross bar which was a circuit switch element that is why we have learnt it and we have converted into a packet switch, but my throughput performance is limited I have to now move one step ahead further improve the performance. Now, how we will improve the performance? So, what we can do? We can do buffering some kind of buffering can be done. So, let us see if we can do the buffering, but we have to do the buffering now question is this some people can say what I can do is I have this cross bar now I am cross bar output. So, I am showing on this side and this side not in the bottom. So, where I should put the buffer. So, there are four lines for example, this four by four where I should put the buffer I cannot insert a buffer inside a cross bar is up now cross bar is a cross point in every slot. I just snap certain cross points and this snap cross points sets will keep on changing in every time slot. So, we have to put the buffer can I put it at the output no we cannot do that. Because there will be only one packet coming at output and that anyway you will always have a chance to translate. So, this buffer will always remain empty packet comes it goes out packets are being lost here because the contingency is happening here. So, common sense will tell I think I can have the buffering here I need not have buffer at the output, but once you do this now if that packets are coming and they are being read out synchronously from the buffer any packet is of fixed length again that is assumption here. Now, there are two packets at the head of the line this is known as line this is head of the line is the first position in the queue and they both want to go to same outgoing port. So, what I will do is I will just read one of the packets and this packet will go out this one this packet I will not read this will remain in the buffer these packets will be read because they are not contending. So, they will be clear, but in the next time slot this is empty. So, new packet will come. So, a new packet will be coming here next time slot a new packet will come this will be in the back next time slot this packet will come a new packet will come again if there is a contention between this packet and this there can be many things which can happen. So, contention will always be looked into only in the this front packets the back packets we are not bothered as of now. So, again if there is a contention I will choose the maximum number of packets which can be transmitted and then of course, once you have decided on that maximum number of packets which need to be transmitted some packets which are cannot go through because there is a contention they will again be buffered. So, this buffer can keep on filling and keep on going out depending on this. Now, there is a problem actually in this case there can be a scenario there are variations on this now. I can have a case like this if I look at the front of the packets this is a current situation for example, this is a current situation there are two packets buffered here one here one here one here and if I allow only the packets which are at the head end there might be contention between these two if there is a contention I may allow this one. So, there are two packets in the buffer, but if I take this combination this one there is no contention all four of them can be transmitted simultaneously because there is no contention among that pair, but since I am using first in first out discipline here all the queues I will not be able to transmit this packet even when this could have been adjusted actually this would have improved the throughput. Now, this kind of blocking this is blocking is not because of switch this blocking is happening because of the queue somebody is there ahead of you sitting and he does not want to go through in this particular slot you could have gone, but you are not actually allowed to go this is known as head of the line blocking h o l. So, this is a one variant of buffering this will certainly improve, but this has head of the line blocking problem. So, next variation of this is you are going to have a situation where these buffers are not managed as single queue they can always be managed as a hybrid multiple queue for each input port I can have 1 2 3 depending on because they are end ports this is known as a kind of a different structure. So, packets which are coming in are buffered into multiple buffer corresponding to each output. So, this one at each input port you will have this particular scenario. So, there is no head of the line there is no first in first out for each output you maintain a separate queue. So, earlier you are having n queue now each queue consist of n queue. So, you require n square queue that is the only thing n into n minus 1 queue is technically will be required this guy will be maintaining a queue for all outgoing ports except the output port which is for which corresponds to itself. So, n minus 1 queue is here n minus 1 here n minus 1 here n minus 1 here. So, n into n minus 1 queue will be maintained. Advantage is that when you look at the slot you will now choose the combination in such a way. So, because for example, there was a contention here, but I can then look at the queue number 2 and there is no contention I can always find out a combination such that the maximum number of packets which can go to the outgoing port that is a maximal match problem actually. So, if you do not do maximal match you might have less number of packets possible actually. So, by just choosing appropriate combinations you choose any one of these. So, one of these n minus 1 has to be chosen in each input port. You choose such that the maximum number of mapping can happen to the outgoing ports. So, in every slot you are maximizing on the throughput. So, once you do that then you will achieve the maximum throughput actually and out of the line blocking can be taken care of, but you have to additionally now implement multiple queues and a separate algorithm has to be implemented inside the switch. Sir, here whenever a new packet comes it will go to each one of the n queues in maximum. No, if packet will come only at one port. So, it is directed to only one of the n outgoing ports it will go in that particular queue. Sir, then who decides in which queue you will queue? A priority is a problem here see question is you do not know that when there is no conflict for example, which one of the natural thing technically you should always go for first in first out. So, this kind of queue actually is not required you can the better strategy will be only thing it is slightly complicated to manage, but this way if you manage it is far simpler. But how many interface ports will have this switch? Only one interface one interface is there one packet will come and it will be directed to one of the ports. So, single buffer I am now strating into n buffers. So, one queue I am strating into multiple queues. In this multiple buffers if it is using round robin laying then we actually it is. So, there is a complication I should actually always the delay is the issue. One of the important thing is not only I should maximize the throughput I should also minimize on the delay of transfer. The problem is you get a packet for this particular thing it went to packet number 2 then the next one the packet number 1 has come. Now, only for packet on the only for output 1 the packets are keep on coming in and if by your strategy you are always choosing one this guy will keep permitting indefinitely your first in first out this one will not be maintained. First in first out you are going to have keep on this line if this out of the line blocking will happen. This is true the second packet is in first line packet has come and second line there is a contention. Again the first line you have given the priority to first line not second line. No, you choose randomly between them. You can choose randomly or first time has been given the second time you will start from the second one and third time you will start you can do around robin. Otherwise there will be a start. Because they are also maintaining queue. If first and second was contending first one was given last time last slot the priority this slot if there is another contention I will start from 2 for giving the priority. So, next time I will start from 3. So, I will keep on doing round robin that is also possible. Well there are various possibilities in the switch it is not that it is very simple trivial thing and there is only one possible solution. I am saying that at each input port there are n buffers. When a packet arrives there is one packet arriving in a slot depending on the outgoing port I will put it in one of these tubes. For output port there is a tube. So, n square complexity will be there for number of tubes. And then it is like I have to now map on to 1, 2 n possible outgoing things I found out 1 can be mapped here. Then 2 can be mapped here. So, I have to find out maximum maximum number of packets can be transferred in a slot that is a maximum match problem. The complexity of the switch as a whole will increase in this such a case. Yeah complexity of processing is increasing. Because you need a algorithm. There is something called buffer complexity which also comes into picture for the same throughput performance. So, it is not same as circuit switching because of this. Circuit switching you are only worried about computational complexity is one thing. If you have to do rearrangements or try to find out a path and second thing is number of cross points. A number of cross point complexity is not the issue. Mostly it is the processing which is the problem. A size gross processing complexity will increase. In this case again I think it will increase quite fast actually it is not desirable. Ideally I want everything to be O n or even lower than that. Every kind of complexity should be this or lower than this. The tendency of the switch is always going to have something O n square. You usually will not find anything greater than O n square complexity. That will be rare phenomena. If that is there I think that is a really bad design. So, you will usually are going to have something in between this. Something in between this is O n log 2 n. You have seen all this I think already. Remember you have got all this stuff. O n log 2 n square kind of thing. There are many combinations which exist in between these ranges. If you can get something better than this, wonderful. If you can get O log 2 n that is still better because that is better than this O n. So, all kind of computational complexity time required to make the decision, the delay part, the throughput performance, the switch cross points which are required. As n grows what happens to that and that is what is complexity. So, this has to be somewhere in between this and closer to this I think it is acceptable. If it can be even lower than this, it is still better. Yeah, it has to be 1 to n minus 1 actually. One of them will not be used. One will be different. If it is a height slot, height input port, then the height buffer will not is not required. You will not be buffering for yourself. You will never have any package directed to yourself. Now, I can further improve. This was one possibility to remove the head of the line blocking. So, usually and of course, there is a maximal match issue. That is another complication. So, people thought of an output queued switch, but we know that output queued switch is going to be difficult to implement. So, how that can be done? It is not that it cannot be. It can be done. What you do is you have 4 ports, one packet coming in every slot per line. So, there are 4 packets coming in. In one time slot, if somehow, because technically it is like a memory which is there, one packet being coming in is stored. While reading out the packet, if I read it at 4 times faster speed, so switch internally is working at not at the line rate, but 4 times the line rate. I am taking an extreme case. So, line rate internally or internally speed is 4 times. In this case, then all 4 packets I can read. I can analyze their header and all 4 of them can be pushed out to an outgoing port in one time slot. So, you will get all 4 packets here, but in one time slot, the line rates are assumed to be same on both sides. Only one packet can go out on the line. What you will do with the remaining 3? You can put a buffer here. So, all 4 packets will be queued up here. Remaining buffers will remain empty. Remaining buffers will remain empty actually in this case. Now, this speed up of 4 times allows this thing to happen, but who said the speed up always has to be of 1 or 4? I can have a speed up of 2 also who stops? So, if I have a speed up factor of 2, what will happen? So far, 2 packets are contending. I can push both of them to an outgoing port. The moment they are 3 which are contending, I cannot do that. One of them have to be dropped. So, 2 of them will be pushed out. One of them will be dropped. Again, some policy decision has to be there regarding this mechanism. Now, this I am now moving to a hybrid approach. If I want to even forget this particular loss, I can also have an input buffering. So, I can even have buffers here. So, when the speed of factor k, so the maximum value of k is always greater than or equal to 1 or less than equal to n, where n is number of ports. Actually, n minus 1 is good enough again. I have written n, but n minus 1 is good enough. And if I am using somewhere k which is not n, n which is greater than 1, I also require input buffers. If I want a lossless packet, there is no loss which is happening inside the switch. So, this is a hybrid configuration. Here, the input side is a normal FIFO. The input side can be a normal FIFO or can be this kind of system. So, there are various combinations now which have come because of in this hybrid thing. So, in this hybrid combination, there will be no loss. Is there a T? There is no loss. When all buffers are full, then what you will do? Like this have to be lost in that case. See, if you are having infinite buffers, there need not be any loss. But, there is a fundamental principle that when lambda over mu which is rho for a cube. This is the mu is the rate, lambda is the rival rate. What we call rho 1 minus rho is what is the average two length l bar. This actually explodes and goes to infinity when rho goes to 1. You require infinite buffer. So, if your buffer is only limited to some value, this is the maximum throughput which can maximum load which can be taken up. That is the average value, remember. So, statistically because this is an average, for this rho this is the average value. So, statistically there can be u which can exceed that average value. And if you are having a buffer only till this average value, like it will be dropped in that case. So, actually average buffer capacity which is going to be there is going to be lower. So, there is a probability distribution which happens for the q occupancy. So, next step I think after the examination we will look into the performance of the input q system when head of the line blocking actually happens. With that and if I remove the head of the line blocking, then what happens that we have already done 1 over 1 minus e. So, I will compare the situation for head of the line blocking and without head of when I am actually dropping the packet if there is a contention. These two scenarios and we will also analyze the output q system and delay is also for that. k is the speed of texture. k is equal to 1 was taken here when we did that full throughput analysis. k is the internal speed of texture. k actually means in one slot I can read two packets and push it to an outgoing buffer. If k is n, I can read all k and packets and they all can be read out to a single outgoing port. k means k time first and we are reading and k time first and we are writing also. Switches internal is working k times at higher speed then the line rates. See line rates are same, line rates are some r packets per slot is a 1 packet per slot. My switch can internally handle k packets per slot. We cannot break it, like reading is something different speed and writing is at this some things are different. They are at different. But both are same. Clear. Clear. How come this and this, the line rates are going to be same on this. If you want to do that you can do that. Then you certainly require a buffer. You cannot work without buffers. You are reading a packet. A packet is being pushed inside in one slot time slot. Here you might be reading out a packet in two time slots. That is the case you shall look. That is possible but I think that is really never used. An input or an output pair. Port pair is always related to a common entity on the other end. Within two for example switching nodes this output is connected to this input and this output is connected to this input. There is always a pair. There is always a bidirectional line. I am showing unidirectional incoming and unidirectional outgoing port on the left and right side but that is fine. But as far as actual systems are concerned they are always a pair. They cannot be unidirectional. With that I think I close today and we will move ahead from here for the analysis part.


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How strict is strict enough? Can only a strict parent be a good parent? Those who are strict but loving are known as authoritative, but those who are strict, controlling, cold, and emotionless are known as authoritarian. Even if it seems like extreme parenting is necessary to teach children discipline, research shows that it actually creates the complete opposite effect. Children raised by very strict parents grow up with all kinds of different struggles with their thoughts, emotions, and behavior. Do you suffer the side effects? If you're not sure what the side effects are, here are six common ones. Number one, the inner critic. You don't study enough. Your room is not clean enough. Does it sound familiar? If you had strict parents, you're probably used to all kinds of critique. Growing up, you might have felt like you never did anything right. Maybe you felt constant fear of being criticized and felt like no matter what you do, you'd never be good enough. These feelings nurtured your inner critic and made it grow alongside you. So today, you might criticize yourself constantly. Maybe you keep bringing yourself down, apologizing for doing things wrong or warning everyone that you'll probably do it wrong. You become quick to point out your flaws before anyone else. This becomes a strategy to protect yourself in hopes that if I criticize myself first, no one else can. Unfortunately, this can often backfire, because your own thoughts can be even more harsh than your parents were. Number two, the bad person. Are you afraid to show your true self to others because you're scared of rejection? This lack of self-esteem and self-confidence is another common side effect of strict parenting. If your parents always had high expectations, you may have set those same expectations for yourself. And as time went on, maybe you internalized those expectations as a part of you. Now, you may feel like your worth as a person depends completely on your results. So, if you fail to meet those high expectations, you may feel like you're bad in nature. Some who were raised in a strict home describe this as feeling like they're fundamentally bad if they don't succeed in following the rules or living up to unrealistic standards. Three, the art of lying. While you were growing up, did your parents always forbid you from doing anything fun? Maybe you weren't allowed to go out with friends or have sleepovers. Most of the time, you did follow the rules blindly, but maybe you snuck out every now and then. Strict parents often expect obedience and respect for authority. They believe they're raising honest and respectful people, but in response to all these strict measures, children learn to act sneaky and become excellent liars. From an early age, it becomes important to learn how to hide secrets and tell a few white lies every now and then.  So now, coming up with a convincing lie is a matter of seconds. Number four, the rules. I can't wait until I get out of here. I can't wait to live however I want without any rules.  Do you feel like you have a need for rules and structure? One example of this need could be functioning in social settings. For example, you may feel a bit more comfortable at work or school. And that's because you know the rules. You know how you're supposed to behave and what's expected of you. But when you're at a party, you're not so sure anymore. What do you talk about? How do you act? In these situations, the rules and structure are not clear. For some adults that grew up with strict parents, this can become a challenge and they might feel lost without the guidance. Number five, the rebel. I'm helping you get disciplined.  Strict parents often justify themselves by thinking their parenting methods would make you a polite and disciplined person. But studies have shown that harsh parenting actually produces kids with behavioral problems. They might have learned to become more rebellious, angry, impulsive. And aggressive when things don't go their way. Also, they're more likely to engage in risky behavior, such as running away or experimenting with drugs. It might be because you want to compensate for the lost time. To some people, it may feel like finally being released to freedom after feeling like a prisoner their entire life. And number six, the sadness. Unfortunately, strict parenting can have serious side effects on your mental health as well. Studies show that kids raised in a strict household tend to be unhappy and show more depressive symptoms. Do you feel sad or anxious as a result of your upbringing? If you often feel hopeless, tired, bored, and if you feel like you don't enjoy things that you used to, you may be suffering from depression. On top of increasing your chances of developing mental illness, strict parenting increases the risk of suicide. Research has shown that in some countries, such as Hong Kong and Australia, kids raised in strict households are more prone to suicidal attempts or ideation. Please remember, if you or someone you know shows signs or symptoms of suicidal ideation, please contact a mental health professional or visit the link for international suicide hotlines in the description box below. Growing up this way may have left you feeling hurt and confused. And unfortunately, it takes some time to recover from the lack of love and abundance of harsh rules. A good way to start that journey would be to acknowledge that you shouldn't feel guilty or ashamed. Accept yourself for who you are, even if you sometimes make mistakes. The mistakes are what make you human, even if your parents never realized that. Do you relate to the points mentioned in this video? What are some other side effects of strict parenting that you have noticed? If you found this video helpful, remember to share with anyone who may benefit from it. Looking forward to seeing any thoughts or suggestions you might have as well in the comments down below. Thanks so much for watching and see you next time.


Everybody forced here ripping two boxes of 2023 top sterling baseball hobby for John a appreciate the order John Let's pull you a cut auto bat knob all the above. Let's do it. Let's do it. Never watched us. I don't Proceeds and performers and rookie of the year award winners Scott Sterling 19 of 25 dual relic auto Greg Maddox Professor right Greg Maddox 19 at 25 dual relic auto Cubs Jersey and rookie of the year award winners each year. Oh One of one jumbo letter patch the sea From each year.  That's what we like to see right there See, let's see another each row jumbo letter patch right here. Let's see the age Let's see the age 2020s MLB all stars of World Series champions. I don't think he's either of those I don't think I don't think it's gonna be in one of these Is it Marlon's each row?  It is I Was wondering because it looked like at first it looks like Mariners because that's silver trim. No, that is Marlon's 2020s all serves here didn't even notice that good catch for show. Hey, oh Tani dual relic auto 12 of 25 Well, John, I'd say you killed it so far got one more hit to each row and Otani. That's uh, that's a pretty good day right there And World Series champs on this one Al Ripken jr. Dual relic auto 18 of 25 Good one to end it as well Hey, John appreciate the order as always man. We'll get him out to you