Ever heard the old phrase strike when the iron is hot? Well, it's never been hotter than now. All this month at Appalachian Wireless, you can get the Samsung GS6 or the GS6 Edge for just one penny when you set up for service. The Galaxy S6, normally $49.99, now just a penny. The Galaxy S6 Edge, normally $99.99, now just a penny. Strike now while supplies last. Better service, bigger savings. Serving you for the last 25 years at Appalachian Wireless. It's time for Mountain Music, presented by Mountain Music Exchange, the heart of music in the mountains. Welcome to another edition of Mountain Music. This week down at Mountain Music Exchange, we've got Prestonburg native Josh Hicks. Take a listen. Features in the summertime, apples in the fall. If I can't have the girl I love, I don't want none at all. Shady Grove, my little love. Shady Grove, I know. Shady Grove, my little love. I'm bound for Shady Grove. Josh can remember having the desire to play guitar from a very young age, and not only was his family a great musical influence on him, but a local entertainer from a local opera house as well. I remember when I was around 12, my father always had a guitar around the house and I always wanted to play. I remember taking curtain rods and playing when I was young, and a gentleman from the Kentucky Opera came around and said that he could teach us any string instrument we wanted in school. So I took my father's guitar out there and never really looked back. I wish I had banjo strings, gold and twine. Every tune I play on it, I wish that girl was mine. Josh says there's nothing that makes him feel the way he does when he's playing.  It's always been a big topic of discussion at the house with my parents, my family. A lot of them was musically inclined. I just feel comfortable when I have a guitar in my hand. I always have music changes the way I feel. Music is just a big part of my life, I guess you could say. There's a reason a 300-year-old folk song never dies. People like Josh and others keep them alive by continuing to play them and pass them on to the next generation. Old folk song called Shady Grove. I found it, Jerry Garcia, which is a great influence of mine. He did a lot of bluegrass and folk music and he had an album in the 90s with David Grisman and they did a version of it and it always stuck out to him for some reason. They did a whole album of nothing but 1700, 1800 folk songs and it always really stuck out to him for some reason.


Love playing racing games on your PC or gaming console? Well, there are tons of racing games for Android that you can enjoy anywhere even without the internet. Hello everyone, welcome to Sistvig, this is Shivani and in today's video we will talk about the best offline racing games for Android that you can get easily. These racing games not only provide tons of fun and challenge to players, but some of them also offer an optional multiplayer mode so you can race alongside your friends. But before we proceed, we want to tell you about a way to ensure smooth game performance on a low-spec smartphone. Cleaner for Android apps remove all junk and clutter from your smartphone and boost RAM speed by clearing out unnecessary background apps. Not only this, but the specialized game speedup module adds a literal boost to your game performance. So before you start playing the games in our list, download and install Cleaner for Android for non-stop gaming action. Please find the link in the description box below. So let's get on with our list. 1. Asphalt 8 Airball With its amazing high-performing machines from cars to bike, you can have the best gaming experience. Take any of your favorite on a globed tour of speed and hit the ramps beyond limits. 2. Asphalt Extreme An off-road racer from GameLog follows no rules and offers a variety of vehicles to ride. There's plenty of racing tracks to choose from in this game, ranging from canyons to sandhills. 3. CSR Racing 2 With CSR Racing 2, you can experience the real racing, race with customized cars against players from all across the world. Buy cars and upgrades and play plenty of races. 4. Drag Racing This offline driving game for Android lets you customize and upgrade your car as and how you want. Apart from online play, this game also allows multiplayer gaming. Users can also choose from turns of licensed cars for unlocking. 5. Racing Fever Racing Fever is not only a game. It's instead an addiction for archived racing fans. This is listed among the best driving games and involves a lot of risk to earn coins. To ensure your safety and survival, always keep your car in the middle of the road. Keep yourself entertained even in the low connectivity areas with these Android racing games. Pick the best offline racing game for you and start playing. Hope you liked our video. If yes, then give us a big thumbs up and for regular updates, press the bell icon.


Let's get going. Today is October 26th, 2022, I'm James Pepper, the chair of the Remind Canada's control board. It's one o'clock and I call this meeting to order. Reminder, our staff is organizing a live Q&A session focused on testing, inventory tracking and product registration. The date for that is November 21st at 7 p.m. We do these after hours to hopefully increase participation by people that work during the day or can't attend our meetings during the day. The link to join will be posted on our website. Please bring all your questions about testing, inventory tracking and product registration to that session and we will do our best to get answers to you. So there's a number of new retailers on the list for this week. I just want to keep on mentioning every week that every product that is being sold to the public has to be registered and approved by the CCB. The product registration form in the payment portal is available on our website under ccb.vermont.gov. I know that product registration is new for everyone, but it is a critical step to ensure that everything that's available to consumers is compliant with our testing protocols, our approved ingredients list, our labeling, advertising and packaging regulations. We're getting through these as quickly as possible. The best thing that you can do to speed things up is to make sure that you are submitting everything that is required for each registration. There is an introductory instructions that you get when you initiate a product registration that tells you exactly what you need to submit for each product type. A link to the packaging that you're going to be using is also very helpful in us being able to process these quickly. We also cannot approve a product registration application until the applicant has paid the $50 registration fee. That link is also available right in the same spot as our product registration. If you have any questions, if you have a pending application, if you have questions about it, you can email us. There's an email specific to product registration that goes right to the team that's approving those. It's ccb.products.vermont.gov. When it comes to packaging, another important thing I just have to keep repeating is that all cannabis products, edibles, tinctures, oils, THC-infused beverages, dipped pre-rolls, et cetera, anything that's not flour has to be in child-resistant packaging. This is not just child-resistance. One time, the package needs to maintain child-resistance for the number of servings contained in the package. If it's a beverage that contains 50 milligrams of THC, that is 10, 5-milligram servings. The cap has to be capable of being re-closed and maintain its child-resistance at least 10 times. The child-resistant packaging also has to be the primary packaging for the product. Putting an edible in a non-child-resistant packaging and enclosing it in a secondary child-resistant package does not meet the federal definition of child-resistance. We do have a lesser packaging standard for cannabis flour, but even that package needs to deter children under 5 from opening the package in a reasonable amount of time. We have a very helpful one-pager that summarizes these points. It's available on our guidance page under packaging materials guidance. None of this should come as a surprise. Every other state requires certified child-resistant packaging for all cannabis and cannabis products. This is a federal government requires it for any potentially harmful household products. There is a register that is maintained by the Consumer Product Safety Commission that has a list of every approved certified child-resistant packaging product. Of course, the only monkey wrench that's specific to Vermont is that in order to achieve child-resistance, most product-packaging manufacturers rely on plastic, which we're trying to avoid in Vermont. We recognize the hardship that this ban on plastic creates when it comes specifically to these child-resistant packaging requirements. To date, we've granted a number of product-specific waivers, which allowed the use of a limited amount of plastic packaging when it was necessary to achieve child-resistance for very specific cannabis product types. We have a team here that's looking through all of our outstanding waiver requests. They made some significant decisions in this past week. Kyle, I was hoping I could turn things over to you to update people on those decisions that were made. All right, before I do that, we only want to see your cannabis products in child-resistant packaging. Sorry, I had to do it. So, our team did make a number of decisions. There are still some outstanding, but out of a lot of these denials, we did decide to move forward with two categorical waivers, and they are good for one year. This will be up on our website later today, if not by the end of the week. One is for plastic or rubber push buttons for cannabis products only to achieve child-resistance. The other is specific for liquids, and so you can use a plastic child-resistant cap for liquids. If we see any child-resistant caps that are not part of the stuff we've already approved on anything other than liquids, we will have compliance issues. But if you're making a liquid that needs to, as the chairman said, needs to be open and closed multiple times, we understand that there's not really a company out there that's making lids for liquids in a sustainable fashion at this time. So for one year, if you're making a liquid, no matter if your size is 28-400, 22-400, 18-400, for liquids only, you can use those products as part of your packaging. So those are the two waivers that will be up on our website later today. There could be a number of denials filling out as well, and we're still considering a handful of the 80-some-odd waiver requests that we've received to date. Great. Thanks for that. And if there's any questions, please contact us. We would love to answer your questions before we have to pull a product off the shelf because it has plastic packaging. So other than those comments, we just have to approve the minutes from our last meeting. I was on October 19th, 2022. Is there a motion? So moved. Seconded. All in favor? Aye. All right. All right. Brynn, I'll turn things over to you. I'll be in corny. I need to be a dead. OK. So jumping right into your adult use and medical cannabis register for this week, starting with the medical cannabis program. Our numbers this week are about half of what they were last week. We've had a little bit of a slowdown with respect to renewal applications and new patient applications. Medical staff are still processing applications received within the last 30 days. Moving on to our adult use license applications. These are numbers as of yesterday. We have about 47 new applications that have come in in the last seven days. Again, most of those are for employee ID cards. Staff have issued about 10 new and 11 new employee ID cards in the last week. And you can see that you've got 10. 10 applications that are pending your review this week. Several of them are retailers. And I have some detail for you this week about who is in the queue. So the numbers here, so this is a little map of the state on the right here with a dropped pin for every retailer that has been licensed already or that is up for approval this week or is really anywhere in the queue as of October 18th. So I think that there are two additional in the queue that are not captured in this map or in this table here. But to be clear, these are all retailers that are anywhere in the queue, including those that have been issued. And these little drop pins are not exact locations. They're just dropped in the town in which the applicant is indicating their retail shop will be located. So the table here shows the breakdown of where all of these potential and existing retailers will be. The total right now is 47. I do think that, like I said, there are two more in the queue. But obviously, the vast majority are proposed to be or are in Burlington. So for the board's consideration. Can you leave this up for just a second? You know, we mentioned at a meeting, I don't know, last week or the week before that we don't have any intention of closing the retail application window. And I actually, when I look at the map, it looks like a pretty decent distribution. However, it is concerning to me that there are nine in Burlington. You know, Burlington, I don't think if this were liquor and lottery, they would not grant nine liquor store licenses to one town, even if it was Burlington. And so I just, I think if we can keep this map relatively up to date each week on our website, anyone who's thinking about getting a retail license should really consider what the population base is, what the customer base is, and how they intend to kind of compete with, you know, if you're thinking about Burlington, nine other locations that are kind of in a very small radius. So we can do that. And we can give some more detail about where that is on the website. But by the end of the week, we should be able to have this map up. And the table needed weekly as we get our new application numbers in. So we'll move on now to the staff recommendations for a license. So as always, this is pushing through all of our applicants that staff has determined to be appropriate for a license given that they've met all the requirements in statute and rule. So for this week, we have Taconic Chronic, applying for an outdoor tier one cultivation license, Vermont Organic Health and Beauty Solutions applying for a tier one manufacturing license, Clovis LLC applying for a mixed tier two cultivation license, Brass Queen applying for a retailer license, Zen Barn Ventures, another retail license, The High Country Retail Applicant, A&R Cannabis applying for a tier two manufacturing license, Magic Man applying for a retail license, higher elevation retail license, and Vermont Kind LLC applying for a tier three manufacturing license. That is your list for this week. Here is our license amendment list. We've got one new amendment in the queue. And then this page is your social equity numbers. So we have from last week, we have an additional four social equity applicants that are moving through the queue. And we have two recommendations for social equity status approval this week. We have submission number 1653, who we are recommending that the board approve social equity status for this applicant since they meet the definition of a social equity individual applicant as defined in board rule. And submission number 1212, recommending social equity status for this applicant since they meet the criteria for a social equity business applicant. And that is your list for this week. Great. Any questions for Bryn? Nope. Nope. All right. Is there a motion to approve the staff recommendations? I move that the board accept each of the recommendations as presented to us in this meeting. All in favor? Aye. Aye. All right. Well, I think the last thing is public comment. We'll do this the same way we always do. If you join via the link and would like to make a public comment, please raise your virtual hand and start with those. And then afterwards, if you join via phone, we'll move to you and you can hit star six on you yourself. They're all stunned by your singing. You know, do a verse if we want. All right. Anyone via the link? And if not, we'll just move to anyone who joined via phone. Again, it's star six. If you want to unmute yourself to make a public comment, I will close the public comment window. Looks like we got one. Eli. Thank you very much. I just wanted to note the testing log jam. I know we've got some other labs in process. And just on the ground, that's a huge challenge for all of us producers. We can't do anything without COAs. So I just wanted to throw some gentle encouragement. I know everybody is working hard over there, but getting through this testing log jam is really an issue for us on the ground. So thank you very much for whatever we can do. Yeah, thanks, Eli. Any other comments? I will close the public comment window. I think we have Steve Hill is on the verge of being licensed if not today or sometime this week. That's one more. I know that's not enough. We are working with other facilities to get them up and running. I think they're licensed, but not yet open. Is that right? Or have not begun testing? So they have conditional approval. That's right. I'm not yet licensed. My understanding from where they are in the process is that they will be ready for your approval next week to begin operating. All right. Well, any other final comments? I'm blouses. I will adjourn the meeting. Thank you.


I am Prasanth Vishwanath Dinshati, Assistant Professor, Department of Civil Engineering from Vuljan Institute of Technology, Solapur. So, today I am here to explain you about the influence line diagram for a shear force at a given section of a girder. The learning outcome of today's lecture is students will be able to study the effect of moving load on shear force of structural member, they will be able to construct influence line for shear force and they can calculate the shear force for the system of loads. Influence line diagram for shear force function, so it is a curve or a graph that represents a function like the shear force at a section of a structure for various position of unit load on the span of the structure is called influence line diagram for that given function. Influence lines are very important in the design of structures subjected to a greater live loads. With influence line it is easy to determine the location of the live load which will cause great test influence on the structure for a given function. Moving or live load moving load are the loads applied to a structure with the points of application including their magnitude can vary as a function of position on the structure including their magnitude means the magnitude of the moving loads are also variable. Shear force at a given section using ILD for the moving loads. Can you define a shear force here, pause the video and try to write answer on a paper. Shear force it is the algebraic sum of vertical forces at any section of a beam to the right or left of the section is known as shear force. It is also called as unbalanced vertical force. Shear force diagram is one which shows variation of shear force along the length of the beam. Static shear force diagram so static shear force how we define so here beam is there and a point load is applied here so to draw a static shear force so we have to consider the sign convention though the left of the section upward it will be positive and right of the section downward will be positive. So now here I have taken the reactions here WB by L and WA by L so when I consider a shear force on the left of this section W so I will get this only one force that is reaction and that is upward means it is positive in nature so I have drawn here WB by L and it is constant up to this point load and when I have to consider the shear force at this side so I am considering the right side of the section so only one force is there that is reaction that is WA by L so it is upward but our sign convention is right of the section downward is positive here upward means I have to show it negative so I am drawing here in the lower side so WA by L and it is constant up to this point load when I join this I will get a shear force diagram. This shear force diagram is for static loading condition now shear force diagram at a section for a moving unit load so when a unit load moves from A to B what will be the shear force diagram let the unit load moves from the span A to B and D be the section where we have to find out the shear force now this AD portion is having length A and DB portion is having length B when the unit load is between A and D now here the unit load is between A and D so here may be the unit load the shear force at D section so shear force at D section what it will be so I will consider the right side of the section so right side of the section only I am having one reaction that is upward reaction but right side of the section so downward is positive upward is negative so it is VB reaction so I am drawing this reaction downwards so we know that VB varies from 0 to 1 as the load moves from A to B so this I have explained the how to find out the influence line diagram for the reaction in the previous video so kindly watch that previous video for the reaction of ILD now so I have drawn here 0 to 1 in the negative side so as long as the unit load is between A and D so my shear force at D will be minus VB now when the unit load comes beyond point D when the unit load moves and it is between D and B section now I will consider the shear force to the left of this section so to the left of this section I am having only one reaction that is RA or VA so shear force at D is plus VA because now left of the section upward is positive so here again we know that VA varies from 0 to 1 as load moves from A to B so as it is positive I am drawing it upwards so this will be the ILD for reaction VA now this both the part the part of the influence line diagram between VB A and D is negative and the part of the influence line diagram for VA between D and B is positive so here both will constitute the influence line diagram for the shear force at section D now here I am drawing the section so this left side will constitute a negative and this right side will constitute the positive value for the shear force at this section D now we will determine a shear force at a section for a given system of load so now the shear force is again can be found out by multiplying intensity of load into the ordinate of the influence line diagram corresponding to the position of the load now these are the load and I have to find out the shear force at this section D so as explained earlier so we have to draw this ILD for VB in the negative direction and VA for the for in the positive direction and here I am sex drawing a section line here so at this point so from this point D of onwards it is having positive value and this is having a negative value so now I have to take this corresponding ordinate for this load for the 7 kilo Newton what will be this ordinate so I can easily find out this by using similarity triangle so this will be 1 by 6 and this will be 5 by 12 so now I have to multiply this shear force at D will be 7 into this ordinate so as it is in the negative portion I will have a negative sign here minus 1 by 6 plus 6 into this again negative ordinate minus 5 by 12 plus 5 into this ordinate it's positive that is 5 into 1 third so I will get the shear force at section D as minus 2 kilo Newton now to determine the maximum positive shear force at a section D 4 meter from left end for a 2 wheel loads any wheel load can lead the other so here the 2 wheel loads are passing which are having a fixed distance 2 meter from the distance between them so now what will be the position so when you will get the maximum positive shear force so for that I have constructed this ILD so this ILD for VB is negative ILD for VA is positive so now observing this diagram so what I understand is for that maximum positive shear force I should have both the wheel loads on the this portion that is in between D and B so now the heavier load should be just right side of the point D but for calculation we can take it exactly on the top of the point D so now I have to take this ordinate and this ordinate as both these are in the positive area so this 20 into 3 4 plus 8 into 5 8 so it will give you 20 kilo Newton positive shear force now to determine the maximum negative shear force at a section D for the same load case that is having 2 wheel loads and at a distance of 4 meter from the left end so what I have to do again you observe this influence line diagram so this portion is giving a negative value this portion is giving a positive value so for maximum negative shear force your wheel load should be in the portion AD and the maximum or the heavier load should be exactly near the point D or just left of the point D but for calculation you have to take exactly at point D so therefore maximum negative shear force at D is 20 into this negative ordinate minus 1 4 plus 8 into this ordinate minus 1 8 so that will give you minus 6 kilo Newton now to determine the shear force at a section D for a given system of load that is UDL so shear force again here we can find it by multiplying intensity of load into area of influence line diagram between the UDL so now here I have drawn the section so this part will give you positive portion this will be having negative portion so again I will take this ordinate for the starting of UDL and end of UDL so this shaded area will give you the area of influence line diagram multiplied by load intensity so here again this is a triple ZL so area you can calculate by one half sum of parallel side into height so this will give you positive value this will give negative value so solving this I will get minus point 57 kilo Newton now for the positive shear force what position should be there therefore so seeing this ILD so I should be placing the UDL on the right portion so here again I am having the right portion so this area into the intensity will give you positive shear force that is plus 8.57 kilo Newton and for maximum negative for the same case so I should place this UDL to the left of the section as this gives the negative value into this area into intensity I will get the negative minus 5.14 kilo Newton these are my references thank you thank you for watching my video


the fifth lecture on simple linear regression. The content of today's lecture is you know we will be talking about confidence interval for the regression coefficient beta 1 and then we will be talking about interval estimation of the mean response and finally, we will be talking about prediction of new observations for a given value of regression variable x equal to x naught. So, before I start talking on interval estimation on interval estimation for beta 1, I want to just recall the important parameter I talked about in the last class that coefficient of determination that is r square coefficient of determination which is defined by r square denoted by r square r square is equal to ss regression by ss t. So, this one is basically this r square it measures the proportion of variability in the data or in the response variable that is explained by the model or that is explained by the regressor variable. For example, if we consider the Disney toy example there r square is equal to ss regression was 4.9 and ss t is 6. So, this is equal to 0.82. So, the meaning of this one is that 82 percent of the total variability in the response variable or the total variability in sales amount is explained by the amount of money spent on advertisement. Well, we know that the range for r square is from 0 to 1. We discussed when r square is equal to 1. Let me consider the case r square equal to 0. Well, so r square is equal to 0. Well, so r square can also be written as 1 minus ss residual by ss t. So, this quantity is going to be equal to 0 if ss residual by ss t if this ratio value is equal to 1. That means r square is equal to 0 when ss residual is equal to ss t. So, what is ss residual? ss residual is summation y i minus y bar sorry y i minus y i hat square which is equal to summation y i minus y bar square i is from 1 to n. So, these two quantity are equal when y i hat is equal to y bar. So, basically if the fitted model is y hat equal to y bar then r square value is equal to 0. That means this fitted model it does not depend on the regressor variable. Well, so the situation I mean suppose we have some data and we have a set of observations i y i and the fitted model is this one which is y hat equal to y bar. That means the significance of this one is that x y this way is that there is no relationship between the response variable and the regressor variable. I mean this will happen y hat equal to y bar will happen when there is no relationship between y and x. Also in other way you can think about I mean this will happen when beta 1 is equal to 0.  So, this will be equal to 0 when beta 1 is equal to 0. Well, so next we move to for the confidence interval for beta 1. Well, so our model is y equal to beta naught plus beta 1 x plus epsilon. So, this is called the intercept and this is beta 1 is basically the slope and we know that the least least square estimator of beta 1 is beta 1 hat which is equal to s x y by s x x. So, this estimator is the result of least square estimate and this is in fact more precisely this is called the point estimation of beta 1. So, the concept of interval estimation is that you know instead of giving a point estimate of some population parameter the interval estimation gives an interval such that the probability that the population parameter will lie in that interval with high probability that means may be the with probability 0.95 or 99. So, the technique to get you know the interval estimation is that you find first you find the point estimate or you find the point estimator of the population parameter and then you find the sampling distribution of the point estimator. Well, so here the beta 1 is equal to s x y by s x x we need to find the sampling distribution of beta 1 hat. We know that beta 1 hat is an unbiased estimator of beta 1. So, this is that means beta 1 hat is equal to beta 1 and also we know that the variance of beta 1 hat is equal to sigma square by s x x and also we have proved in previous lecture that you know this beta 1 hat this one is basically it is a linear combination of random variables y i and we have assumed that y i's are normally distributed. So, any linear combination of normal variable also follows normal distribution. So, beta 1 hat we know that beta 1 hat follows beta 1 hat follows normal distribution with mean beta 1 and variance sigma square by s x x right. Well, from here we can say that beta 1 hat minus beta 1 by sigma square s x x root of this follows normal 0 1. Well, but the situation is that you know most of the cases sigma square is not known then we replace sigma square by its unbiased estimator that is m s residual. So, if we replace m s residual if we replace sigma square by m s residual then this random variable beta 1 hat minus beta 1 by m s residual by s x x this follows t distribution with degree of freedom n minus 2. Now, so what we got is that we got that beta 1 hat minus beta 1 by m s residuals by s x x this follows t distribution which is degree of freedom n minus 2 and let me call this equal to t. Now, we need to have a confidence interval for beta 1 well suppose this is the t distribution. Now, we will take two points this point is t alpha by 2 n minus 2 the meaning of this one is that t greater than this one and the probability of this this area I mean this portion is alpha by 2. So, from here and this point is this point is minus t alpha by 2 in minus 2. Now, beta 1 hat minus beta 1 by m s residual by s x x we can say that this t this is basically the t. So, t is in this interval t alpha by 2 n minus 2 greater than t alpha by 2 n minus 2 with probability 1 minus alpha. So, to make this probability high we have to choose alpha accordingly if for example, if if we want to make this probability say 0.95 then then we have to choose alpha equal to 0.05. So, from here we get the confidence interval for for beta 1. So, we say that 100 into 1 minus alpha percent that means the if we choose alpha equal to 0.05 this quantity is going to be 95 percent confidence interval for for beta 1 is obtained from here simply algebra write beta. So, the range of beta 1 is is beta 1 hat plus t alpha by 2 n minus 2 root over m s residual by s x x and the lower bound is beta 1 hat minus t alpha by 2 n minus 2 m s residual by s x x. So, this one is this one is basically you know 95 percent confidence interval for beta 1 the meaning the in other word we can say that the that the population parameter beta 1 which is basically the slope for the simple linear regression model. This will lie in this interval with probability 0.95. Let me explain this one in the toy example in the Disney toy example. So, what we got is that the upper bound was beta 1 hat plus t alpha by 2 n minus 2 root over m s residual by s x x this is the upper bound for beta 1 and the lower bound is beta 1 hat minus t alpha by 2 n minus 2 m s residual by s x x. So, for the Disney toy example beta 1 hat is equal to 0.7 and there we have 5 data points. So, we will choose alpha equal to 0.05 to make you know probability 0.95. So, t 0.0253 is you see the value of this one from from the statistical table. This one is equal to 3.182. So, what we only need to compute this quantity root over of root over of m s residual by s x x. So, what we have to do is we have to compute this is equal to 0.367 s x x is 10 and you know it is not difficult to now check that the beta 1 will lie in the interval 1.3 0.1. And beta 1 will lie in the interval 0.1 to 1.3 with probability this probability is equal to 0.95. So, this is what the interval estimation is and you know instead of giving one estimate of a population parameter here we give an interval and the use of this interval is that we can say that the population parameter will lie in this interval with high probability that is 0.95. So, next we move to interval estimation of mean response that is E y mean response or expected response for given x equal to x naught. Well, once you have the fitted model you know one important application of regression model is to estimate the expected response for a given value of the regressor variable and also the another important problem for the regression model another important application of the regression model is that prediction of new observation corresponds to a given value of response variable given value of regression variable x. So, first we will talk about the estimation of in fact the interval estimation of the expected response or mean response at some for a given value of the regressor variable x. So, here we want to find interval estimation mean response that is or expected response for x equal to x naught. So, this looks like you know like conditional expectation, but basically what I want to mean by this notation is that I want to estimate the expected response value for given x equal to x naught. That means at x naught point of the response of the regressor variable I want to find the expected response. Well, if you recall the model simple linear regression model y equal to beta naught plus beta 1 x plus epsilon. So, the expected response y at the point x equal to x naught this quantity is 0. It is equal to beta naught plus beta 1. So, we want to find an estimator of this quantity beta naught plus beta 1 x not only I mean we are not looking for the point estimation of this expected response, we are looking for an interval estimation of this expected response at the point x equal to x naught. Well, so again you know we have to start from the point estimation of I mean one estimator of this expected response. We know that an unbiased estimator this expected response y given x equal to x naught is let me denote this estimator by this expected response hat equal to beta naught hat plus beta 1 hat so I should put x naught here. We want to find interval estimation of this expected response at the point x equal to x naught. So, this is an unbiased estimator of the expected response. Well, this is an unbiased estimator of the expected response. Well, it is very easy to prove that this is an unbiased estimator because both beta naught and beta 1 they are unbiased estimator of beta naught and beta 1 respectively. Now, we need to find the sampling distribution of this quantity or this random variable I should say. Well, to get that I need to find the variance of this estimator the variance of beta naught hat plus beta 1 hat x naught hat plus beta 1 hat x naught is equal to variance of variance of y bar plus beta 1 hat x naught minus x bar. What I did here is that I just I have replaced we know that beta 1 hat is equal to y bar minus beta 1 hat x bar. So, I have replaced beta naught hat by this quantity. Now, variance of this one is equal to variance of y bar plus variance of beta 1 hat x naught minus x bar plus beta 1 hat x naught minus twice covariance of y bar beta 1 hat x naught minus x bar right. And it is not difficult to prove that this quantity this covariance term is equal to equal to 0. Now, what I want to do is that I want to write down the variance of beta 1 hat plus beta 1 beta naught hat plus beta 1 hat x naught is equal to is equal to basically variance of y bar which is sigma square by n plus variance of this quantity which is which is x naught minus x bar whole square into sigma square by s x x. Well, so I have replaced beta 1 hat x naught finally, the variance of this quantity is equal to sigma square into 1 by n plus x naught minus x bar whole square by s x x right. So, again you know the same argument beta 1 sorry beta naught hat is a linear combination of y i's beta 1 hat is also a linear combination of y i's. So, since the since y i's follows normal distribution. So, you can we can say that beta naught hat plus beta 1 hat x naught which is linear combination of random variables that also follows normal distribution. So, beta naught hat or we can say that the estimator of y given x equal to x naught this estimator follows normal distribution with mean beta naught plus beta 1 x naught and variance sigma square by 1 by n minus x bar whole square. So, this is x naught minus x bar whole square by s x x and from here from here now the sampling see sigma square is is not known. So, we replace sigma square by m s residual. So, what we got finally, is that this estimator y given x equal to x naught minus x bar whole square minus you know this this one is basically response expected response at the point x equal to x naught by by root of by root of you know m s residual. I am just replacing sigma square by m s residual into 1 by n plus x naught by n plus x naught by n plus x naught by minus x bar by s x x this follows t distribution with with degree of freedom n minus 2. So, we want to find a confidence interval for this expected response at the point x equal to x naught. Now, we have an estimator for this one and we we have the sampling distribution this is called the sampling distribution of this estimator sampling distribution of estimator and from here from here we we we get the 95 percent confidence interval for the expected response and that is given by that is given by well let me write 100 into 1 minus alpha percent confidence interval on expected response at the point x equal to x naught is is e of given I am writing just x naught this is in between e of y given x naught estimator plus t alpha by 2 n minus 2 and then x naught by n minus 2 and then x naught and then that and that here you have root of this quantity m s residual into 1 by n plus x naught minus x bar whole square by s x x and similarly the lower bound is y given x naught this quantity minus t alpha by 2 n minus 2 m s residual 1 by n plus x naught minus x bar s x x and similarly the lower bound is y given x naught this quantity minus t alpha by 2 n minus 2 m s residual 1 by n plus x naught minus x bar s x x. So, this is the this is the confidence interval for this one and this confidence interval is is minimum you know this is this confidence interval is is minimum at x equal to x naught and this widens as and this widens as x naught minus x bar s x bar s x bar s x bar minus x bar the absolute value of this one increases well I mean this looks bit abstract let me give one example for this one you know again you consider the consider the toy example Disney toy example and here what you do is that estimate the estimate means say sales amount when advertisement cost is say 4 dollar at the 0.05 level. So, you know you find out all these things well let me just compute the upper bound for this one. The upper bound is e y given x naught estimate of this one plus t alpha by 2 n minus 2 into m s residual 1 by n plus x naught minus x bar s x bar s x bar s x bar s x bar s x bar whole square by s x x.  So, we know the value of this one this one is basically minus 0.1 plus beta 1 hat is 0.7 and x naught is 4. So, this one is equal to 2.7. Now, we know that this quantity is since in the Disney toy example n equal to 5. So, this one is basically t 0.25 minus 3 which is equal to 3.182. Now, we need to compute this term here what we have is that we know m s residual is 0.367 n is 5 plus x naught is given 4 and you can check that you go you see the Disney toy data. You can check that x bar is equal to 3. So, this is 4 minus 3 square by 10 and this will come out to be 0.367 into 0.667. So, this is the value 0.3 which is equal to 0.3182 into 0.33. Well, so the upper bound is going to be for this quantity expected response at the point 4 is going to be 3.75 and lower bound is obtained by just replacing this plus sign by minus. This will give you 2.7 minus this quantity 3.182 into 0.33. So, this will be 1.65 and the probability that the expected response when the cost on advertisement is equal to 4 the expected response will be lie in this interval with probability 0.95 and you can go back to the you can see the original data there you will see that the actual response value is equal to 2 corresponds to x equal to 4. So, this is how we know we give confidence interval for some population parameter and here the population parameter is beta naught plus beta 1 x naught and we have given 95 percent confidence interval for that population parameter which is here it is basically the expected response at some value of for a given value of x equal to x naught. Well, so another important application of this regression model is to predict the new observation this one is a little difficult you know there is a slight difference between the expected response and what I am going to do now this says that you know next let me let me explain the things we are going to predict new observation predict prediction of new observation well what I want to do is that you know we want to predict new observation say why not corresponds to corresponds to a specific value of regressor a x equal to the difference between the previous one and this one is that in the previous problem we want to expect it response and here we want to predict the observation at the point x equal to x. So, the difference between you know the previous and this one is that see why not is nothing, but why not is nothing, but it is a new observation given the data we have the we have fitted the model and now using that fitted model we want to predict the response value at a new point. So, we want to predict why not which is basically beta naught plus beta 1 x naught plus epsilon we want to predict this one and the previous problem was we wanted to predict or we wanted to estimate expected response at x equal to x naught which is equal to beta naught plus beta 1 x naught. So, here we want to estimate why not which is equal to this quantity and in the previous example we wanted to estimate expected response which is equal to this quantity well now again if x equal to x naught then you know beta naught hat plus beta 1 hat x naught is we want to predict why not. So, we will start from this point estimator well now we define random variable psi which is equal to this is bit tricky which is equal to why not minus why not hat my why not hat is nothing, but this quantity this is equal to this is basically why not hat. Now you can check that it is not difficult to check that expected value of this new random variable psi is equal to 0 and the variance of this new random variable psi is equal to variance of why not minus why not hat which is equal to the variance of see why not hat this why not hat is this quantity beta naught hat plus beta 1 hat x naught. So, the whole thing it is a function of y 1 y 2 y n the given observation, but why not is a new observation and this one is independent of y 1 y 2 y n. So, why not hat basically involves y 1 y 2 y n and why not is a independent observation. So, that is why we can write the variance of this quantity is equal to variance of why not plus variance of why not hat. Now the variance of y 1 y 2 y n is equal to y not hat we know because just now we have computed the variance of this quantity it is not difficult to check and variance of why not is equal to sigma square. So, variance of why not hat so variance of psi is going to be variance of well sigma square plus variance of why not hat which is equal to sigma square plus sigma square by 1 by n this one we just we have proved that this is equal to x naught minus x bar whole square by sigma square x x because why not hat is nothing, but this one is nothing, but beta naught hat plus beta 1 hat x naught. So, this is sigma square into 1 plus 1 by n plus x naught minus x bar whole square by sigma sorry this is s x x this is s x x well and we know that the sampling distribution of psi psi minus expectation of psi is equal to 0 by beta naught. So, variance of psi this follows normal distribution, but now if you replace in the variance of psi this sigma square by m s residual then this is going to follow t distribution with degree of freedom n minus. So, from here we get 100 into 1 minus alpha percent minus 1 minus we call it prediction interval prediction interval for why not is why not lies between not hat plus t alpha by 2 n minus 2 into the whole thing m s residual into 1 plus 1 by n plus x minus x naught x naught x bar whole square by s x x. So, this one is the upper bound for why not and the lower bound is why not hat this plus will be just replaced by minus. So, this is t alpha by 2 n minus 2 by into m s residual 1 plus 1 by n and this quantity plus x naught minus x bar whole square by s x x. I hope you can understand because basically this quantity is nothing but this one only the sigma square has been replaced by m s residual. So, this is the you know 95 percent if you put alpha i call to 0.05 then the probability that the future observation and then the at x equal to x naught will lie in this interval with probability 1 minus alpha that is basically 0.95 and here you know of course, this interval is minimum when x equal to at the point x equal to x naught and this interval is always wider than the interval given for the expected response at the point x equal to x naught. So, here this is all for today and this is perhaps you know this is my last class on simple linear regression and next in the next lecture we will be talking about multiple linear regression. Thank you.


The Fish FAD program of the Food and Agriculture Organization of the United Nations is working to improve access to tuna and pelagic fishes by promoting domestic anchored FAD programs in the Pacific Islands region. This video will demonstrate outboard motor troubleshooting techniques for small scale fishers that can help improve productivity and safety at sea. The two-stroke outboard motor is by far the most popular and common engine used by small scale fishers around the world. This training video aims to provide information on troubleshooting and maintenance to help improve safety at sea for small scale fishers. Before you go to sea, ensure you have your engine tied to the boat with a safety rope in case the engine may come loose during operation in various sea conditions. Also, ensure your engine is running well. Listen to the engine to hear if there is any strange sound. Your engine must be running correctly and must clearly show the water pumping out from the engine's water cooling system. Pictured here is the minimum tool kit that should be carried by any small scale fishing craft going to sea for daily fishing trips. Note the essential open end ring spanners, Phillips and slot drive screwdrivers, spark plug spanner and spare spark plugs, rope for emergency engine start, pliers and vice grips, and spare fuel hose fitting. The fuel tank providing fuel to the engine is the first step approach if you experience issues with your engine. The fuel hose needs to be connected to the fuel tank with the fuel hand pump arrow pointed in the direction of the engine. Often, as fuel tanks are extensively used, the barbed fittings on the fuel tank can become damaged. This can then damage the rubber seal on the fuel hose fitting and allow air leakage and therefore limited supply of fuel being able to reach the engine. This is why we should always carry a spare fuel hose fitting in the tools and spares kit. In an emergency situation, we can remove the fuel hose fitting and insert the fuel hose directly into the fuel tank. As the fuel hose is regularly removed from the engine, when we go to reconnect at the beginning of a fishing trip, sometimes there can be an air lock in the fuel hose. We should remove the fitting from the engine and then place it on just halfway to allow air and fuel to flow and ensure all air is removed from the fuel hose. Now we remove the engine cover to demonstrate where the electrical system begins. As we pull the starter cord, the flywheel turns around which provides power to the small alternator under the top flywheel and this alternator provides the power required to run the engine. So the alternator provides power to the power pack which then provides power to the coil which then provides power to the spark plugs. This is the electrical system and in this video, we will demonstrate possible solutions to engine failure at sea and help you return home to your family. With two-stroke outboard motors, issues most commonly encountered will be water and fuel or issues with the electrical system. We will start with the fuel system. Note that fuel used today has additives that absorb moisture. This can result in water in the fuel. Also, fuel suppliers can often have issues with their fuel supply storage during periods of excessive rain. We will first troubleshoot issues with fuel. First, we will drain the fuel filter. So remove the fuel hoses into and out of the fuel filter. The fuel filter being plastic is often able to be removed with a rag. Another way can be to tie a small rope around the filter and twist the rope tight to achieve enough grip to unthread the plastic filter housing, unscrewing clockwise. Now we have drained all the fuel in the filter. Often you will see water in the bottom. Note there is a small wire mesh strainer up and under the fuel filter top fitting. Now we will drain all the fuel in the carburetor by loosening the screw at the very base of the carburetor. You do not need to remove this screw, just undo slightly. We also clean the wire mesh strainer at the top of the fuel filter top section. We then ensure we have the rubber O-ring washer on top of the fuel filter bowl and we reconnect, threading it counterclockwise. Remember to hand tighten only. Now we reconnect the fuel line hose into the filter coming from the fuel tank and out of the filter going to the carburetor. Now we hand pump fresh clean fuel into the fuel system of the engine. Notice the clean fuel now draining from the drain screw at the bottom of the carburetor. Now we tighten the drain screw bottom of the carburetor, not too tight. And now we should have resolved the problem of water in the fuel system. The fuel pump is a very reliable part of the fuel system. It will not normally fail completely. And in an emergency, you can hold the fuel tank above the engine and hand pump the fuel hose from tank to engine to supplement the fuel pump and get home. If the pull cord rope breaks, we need to remove the top cover to access the flywheel for emergency start. Remove the bolts and top cover to access the flywheel. Here we use some rope tied in a figure eight knot on the end and this is placed into one of two locations on top of the emergency rope attachment fitting. Then we are ready to pull start the motor. Now we will demonstrate the correct troubleshooting of the electrical system. First start with the minor components. Never jump ahead to a more complicated part of the electrical system. Therefore, the first step is to examine the spark plugs. Here we are checking if we can see spark when pulling the hand crank rope. Using insulated pliers hold the spark end close to some metal component and see if you see spark when the starter is pulled. We did not see spark previously so now we remove the spark plug rubber boots to go directly to the wire end feeding into the spark plug rubber boots. Now repeat the process. With insulated pliers hold the end of the wire to some metal and watch for spark as the engine starter is pulled. If you do not see spark, we will then start to clean other electrical connections. First disconnect this male and female connector. Now use sandpaper or the edge of your knife to clean the metal connection fittings. We reconnect these male and female plugs and we move next to the coil. We remove the coil which has an earth wire connected. We will clean all these metal joining faces. The earth wire cable lug needs to be well cleaned to ensure the coil achieves good earth connection to the motor block. Now we will check the power pack forward side that comes down from the alternator under the flywheel. We disconnect the plug, remove the yellow fitting so that we can place our tester probes down into the metal connection points. We place our tester probes black to the earth and red to the incoming power wire from the alternator. If we pull start the motor we can see if there is power coming from the alternator under the flywheel. Now we remove the top cover of the motor which has the hand start pull cord rope assembly. We are holding the wire that comes down from the alternator and into the power pack. If we use the tester and find no power is being generated when we pull the starter cord rope then we will have to remove the flywheel with a puller. There are different types of pullers. When the flywheel is removed we then see the alternator. This is where the electrical system begins. The flywheel rotates around the alternator to generate power then feeds to the power pack. The power pack feeds the ignition coil and this feeds the power to the spark plugs. We should always start from the simple side of the system. Start with the spark plugs and then work your way to the ignition coil. Then to the power pack and only then to the alternator on top of the engine. We remove the stainless steel split clip from the shaft castle nut. We undo the castle nut and now as we remove the propeller we must be very careful to note exactly how the different washers are placed on the shaft. This is very important. As we remove the propeller we then remove the last washer. It is critical to get this washer correct and to ensure all washers are noted in exact order as you remove and then replace back in same locations as the propeller is fitted back into place. The castle nut is tightened, not too tight and the castle end aligned with the hole through the shaft for the split pin which ensures the castle nut and propeller cannot come off during use. Here you can see the correct placement of the split pin through the shaft and castle nut end. We undo the lower screw in the outboard leg. Now we undo the upper screw in the outboard leg which allows air to enter and oil to drain from the gearbox. Note the milky color which shows some water is entering the system. Also note that both top and bottom screws have a red fiber seal washer. These must be used to ensure the gearbox oil system is well sealed. We now fill the gearbox with oil using a special squeeze bottle. As we squeeze the oil in the bottom it will then fill the gearbox and come out the top. While we hold the pressure with the squeeze bottle in the bottom we then place the upper screw with the red fiber washer in the top and tighten tight. We then remove the bottle and quickly place the bottom screw with the red fiber washer into the bottom of the gearbox and again tighten tight. We remove the anode at the base of the outboard leg. This provides access to the one bolt inside. Then we have four additional bolts to remove. Two on each side for the outboard leg. Now we undo the gear shaft joint and at this point we can pull down and remove the bottom leg of the engine. With the leg removed we have access to the four bolts that hold the water pump and peller housing. We take the top cover off and this gives us access to the water pump and peller. This impeller is replaced as it is worn and we noted that the engine is not pumping water correctly. Note that there is a keyway on the shaft inside the impeller. Here we have 15 horsepower and 8 horsepower outboard motors. We can note that everything we have outlined in this training video guide is the same across all two stroke motors. Other outboard engine repairs not covered in this video guide need to be taken to an outboard motor repair workshop that has specialized tools required.


Achieving decent living conditions and well-being for all remains the biggest challenge for humanity. This is why we do what we do. We are the United Nations University World Institute for Development Economics Research. Are you a new wider? For more than 30 years we have generated ideas that support sustainable and equitable development. Part of the United Nations and based in Helsinki, we are a global think tank that provides a forum for original research and policy discussion. Our work currently focuses on three core development challenges – transformation, inclusion and sustainability. These interact differently in specific country contexts. To create ideas on how best to address these challenges, we bring together local researchers with international experts. Jointly we assess available options and help design effective policies. This is how we work. With a global network of researchers and leading institutions from all around the world, it is the power of the network that gives you a new wider credibility as a quality source of knowledge on development. In the Growth and Poverty project, for example, we brought together an interdisciplinary team of international and local researchers to assess recent trends in poverty and growth in sub-Saharan Africa. A striking diversity of experiences emerged. Monetary indicators improved in many countries. Others are yet to succeed in channeling the benefits of growth to the poor. Some even failed to grow. Simultaneously, a large majority of countries have made impressive progress in non-monetary indicators such as infant mortality rates and school enrollments. These analyses are feeding into government policies addressing the challenges of inclusive growth and poverty reduction in Africa. To be useful, new knowledge is shared and discussed at all levels, amongst researchers, policymakers and practitioners. To illustrate, in wider development conferences, senior and junior researchers share common platforms with policymakers. Conferences also connect developing country researchers to international debates and provide you and your wider with a global voice. All this research and analysis is freely available on our website. You can also find databases as well as short briefings and blogs on key findings. Become part of our global network. Join us in creating and sharing knowledge for development.


All right, so really glad to be back here first off. Doing an in-person presentation, in-person conferences has been so long, and it's one of those things I never thought I'd miss until it was taken away. So I'm just really glad to be here. I'm actually going to take off the mask for a bit. A lot easier to talk. And I'm happy to be here talking about this subject, managing Kubernetes webhooks. Webhooks have been kind of a thorn on my side. I'm sure a lot of others manage them in Kubernetes. Comes with a lot of challenges, and we've been able to use Spire to make the webhook process a lot easier. So I'm Faisal Lemon. I'm a software engineer at F5 Networks. Previously, I worked at Nginx, and Nginx was acquired by F5. Nginx, of course, is the open source web server load balancer solution that a lot of you guys are familiar with. And I'm sure are using in your deployments. The picture there, of course, is my daughter, Salma, and our cat, Marley. We just recently adopted her about six months ago.  She likes jumping on shoulders, so we think she was a parrot in the previous life. So the agenda for today is I'm just going to talk a little bit about the challenges of webhooks, just to set the table. So then digging into how we use Spire to solve those challenges, and then some Q&A as well after that. So let's go ahead and dig into it. So a little bit of refresher on the webhook side. So first off, what is a webhook? So in the world of Kubernetes, a webhook is a callback. And it runs before Kubernetes objects are created, updated, deleted. So any sort of modification of the Kubernetes state, a webhook runs. And then once that webhook runs, you have the opportunity to do something. And so what is that something that you can do? And they typically fall to these two buckets, the two types of webhooks. The first one I have listed here is a validating webhook. And that is used to, as it says, just validate configurations and make sure that they are OK. There's nothing weird in them. There's nothing that's illegal or something you don't want, some state you don't want. A very common use case of the validating webhook is in the custom resource definition, or CRD.  And there's custom rules as to what's acceptable and what's not acceptable. And so you use validating webhook. You have the opportunity to reject and valid configs. A good example in the KubeBuilder book is that they go through how to create a CRD for cron jobs. And so the validating webhook they have there will reject invalid cron configs. A second type of webhook is a mutating webhook. So if you use service meshes like Istio or others, they typically deploy some sort of mutating webhook to modify the pod to inject the side card there. And so that's the mutating webhook and the other comment. So what makes webhook so challenging? And I think the first one really is that you have to provide a certificate, a key, as well as a root CA certificate. So you have to provide all three of these pieces of information, two Kubernetes, and they all have to be kept up-to-date, kept fresh, rotated. And it's up to the operator to do that. The certificate and key have to be saved on disk, which is another challenge. KubeBuilder is more in-memory certificates. The webhook system still requires certificates to be on disk, and that's another challenge, another step in the process. And if anyone knows how to do webhooks without storing stuff on disks, I would love to hear how you accomplish that. And then the root CA certificate has to be provided into a Kubernetes object, the validating webhook or the mutating webhook configuration, in the CA bundle field. And you have to keep that up-to-date. So sample configuration here is just a validating webhook configuration. It has some sort of name. And then you see the CA bundle there field. That's the base 64 encoded root CA certificate. But so is the operator of a webhook. It's your responsibility to keep that up. So how do you manage webhooks currently within Kubernetes? There's a couple of different options. You can use a long-lived certificate. It's a very easy way of getting around the problem. You just have it expire far in the future. We're guilty of doing this as well internally. Not the best way to do it, but it does work. The challenge there is manually, you have to rotate it manually. But if you keep the expiration date, like in the year 3000, probably not a big problem there. But the biggest problem, of course, is that if those certificates leak, it's a security liability. How do you evoke it? So typically, you don't want long-lived certificates. The standard solution that people use for managing Kubernetes webhooks is CertManager. If you follow the CoupBuilder book and the steps they put in there, they have a section on CertManager and how to use CertManager to manage Kubernetes webhooks. It does the auto-rotation for you, which is great. The problem with CertManager, I think, is that it has a lot of overlap with Spire, the most kind of certificate management solutions and deploying both. I think it has a lot of overlap. It has a lot of operational overhead. And for us, it was out of scope just because the only gap that we had with Spire was the webhook, and we didn't want to deploy CertManager. Just purely for the webhook use case, it's a lot of a new tool to learn, new logs. And so we wanted to avoid going down that path. And so the solution that we came up with in working with the Spire team, the contributors and maintainers, is to use Spire to manage certificates. And the solution that we have on Spire is based a lot on how CertManager does it as well. So moving forward, how do we actually use Spire to manage those certificates? There's three basic steps that we need to do, and we'll go through them in detail. The first is that we need to keep that root CA certificate fresh within the validating webhook, mutating webhook configuration, the CA bundled fields. We have to have a way of rotating and retaining that field. And then, of course, we need to create an entry on the Spire server for the actual webhook pod. The server that's going to be servicing the webhook needs the certificate. In order to get that certificate, it first needs the entry. And then on that pod, we need to actually save that certificate and key to disk. So those are the three logistical steps. And just to note that this requires Spire 12.2 or later. That's the release of Spire that we got these changed. The first part of the solution is keeping the CA bundle fresh. This is actually one of the easier parts of it. And the way we do that is using the CA's bundle Notifier plugin. And so if you're not familiar with this plugin, what it does is it takes this Spire root CA certificate and pushes it into a config map, which then you can use to bootstrap your Spire agent. So if you're not using this plugin, you should be. And so what we've done is extend this plugin to also, in addition to pushing the root CA certificate to a config map, we push that root CA certificate also to the webhook configuration. And so the configuration is webhook label, and then the name of the label that you want to use. And then what Spire server is going to do is it's going to filter on that label and pods, or sorry, not pods, webhook configurations with that label. I'm in it. Spire will manage the CA bundle field. So the first box there shows a Spire configuration. So you just specify the actual label you want to use. And then the second box, with the actual webhook, you put in the label field whatever label you specified. In this case, just spiffio slash webhook. Cole and true. And then if that is there, when you deploy the validating webhook configuration, you just keep that CA bundle field clear. And then once it's deployed, we have a watcher on the Spire server. It filters on that label. So anything with that label, Spire is going to push the root CA certificate into the CA bundle field. It rotates and manages it for you. So whenever the root CA certificate is about to expire, it goes through all the validating webhooks, mutating webhooks that have that label set and rotates the CA bundle for you. And on startup, if you deploy the validating webhook first, once Spire server starts up, it gets a list of everything that has that label set and populates that. So all you really need to do is just really deploy your webhook with that specific label and then Spire server the rest for you. So that's step one. And so that manages the root CA field within the webhook configuration. The next thing we need to do is create an entry on the Spire server. There's two ways you can do that. You can just do it manually. You can go onto the Spire server CLI and just do the create entry as you normally would. The only thing you need to pay attention to is a dash dash DNS. So you need to create a DNS name in this specific format, the name of the service that you've deployed along with the webhook.namespace that it lives in.svc. The Kubernetes API server expects that DNS name to be in the certificate. Other than that, whatever you create your entry can be whatever you normally create, whether it's pod name, pod UID, whatever it is that you need, so as long as the pod is associated with that entry. You can also use the Kubernetes workload registrar. That automatically will also add that DNS name that's required to the certificate for you. The CRD version of it has that configuration enabled by default, so if you deploy that, then your pod that services the webhook comes up that will get the certificate with the correct DNS names in it. So now you've created the entry. The most complex part of the whole solution is saving the certificate and key to disk. So there's a lot of code here. The first thing to keep in mind, though, is this is just based on the Ghost50 example, the watcher example, sorry, and the Ghost50 v2 directory. So what you're doing here is we're creating a watcher that watches for new certificates using the Ghost50 client, and then when the new certificate comes in, we save it to disk. So the first thing to pay attention to here is the imports. I have an import in my private GitHub, or not private public GitHub, that just has some routines, two routines to save to disk. If you don't want to import yet another library, you can just go there and just copy those routines. That's not a lot of code. But in case I'm moving forward, we create the Ghost50 client, as you normally would, in this first step here. Let me show up. It's OK. So that first block there. And then the second block there, we started using the Go function. So that starts the Ghost50 client. And then after we start the Ghost50 client, we wait for certificates to be on disk. We have to have a barrier there, because if we try to start the webhook server without the certificates in the disk, it throws out an error, and then crashes and goes into that restart loop. So you have to make sure the certificates are there on disk. And so I have that in my GitHub. There's a little library function that just waits for the certificate disk. The wait for certificates to dysfunction just waits about three minutes. And after three minutes, it times out and gives you an error. And then if the certificates are there, of course, it works. So that starts up the Ghost50 client. The thing to keep out for, one more thing to keep out for, is this X5 and I in watcher field. So we're passing the directory that we're saving the certificates to. To the next part of this slide, which is the watcher struct. And so if you're familiar with the Ghost50 client, what happens is that every time that there's a new certificate, this on context X5 and I in context update gets called. And so what we're going to do is when that gets called, all we do is just write the actual svid out to disk. And so that's also just kind of encapsulated in this library function. But it just takes, extracts the default svid and then just saves it to disk in the directory you specify. The file names are static, cls.ct, cls.key, because every webhook API that I've seen in Kubernetes just requires it to be on those files. And the only configurability you have is the actual. So you just pass in the directory and then we save it here to those file names in the webhook server. So you do it. And then once that's all set up, that whole system will then just keep refreshing the certificates on disk for you. And then you start your webhook server normally either using the control runtime APIs or whatever other webhook setup that you do. Looking forward, I think we need a better way to save certificates to disk. The save to disk case, I think, is a little complex one. There's different ways to do it. I think two options here is just having Ghost50 directly save the certificates to disk. If it can't do that, then just have export some utilities that I have in my GitHub just have those in the Ghost50 library so that the user can just save the disk. Another option that I think would be much more clean and nicely integrated is just to have Spire save the certain key to a Kubernetes secret object. And your pod mounts that secret object, volume mounts it, and then the certificates will live on disk because that's how the secrets are mapped. So I'd work out nicely, and that would also parallel what the cert manager does. Cert manager saves the key and disk into a certificate CRD, which is basically a secret object. So it'd be a nice, nice parallel there. Also great is API service CI bundle. So we extended the plugin from webhooks to API services. So if you're not familiar with API services, it's used to extend the Kubernetes API server with custom API endpoints. We use this in our product to have some custom metrics endpoints, but nonetheless, it has also a CA bundle field to use for the Kubernetes API server to use. And so we added some functionality there using the API service label config to the same plugin. And then you just deploy your API service with that label and then Spire will manage those certificates for you as well. API services are nice because they don't require certs and keys to be on disk. So you can use a GoSpiffy, TLS peer functionality. I'm not worrying about saving stuff to disk. If there's any other Kubernetes objects anyone knows about that have a CA bundle that needs to be rotated, let myself know or open a ticket. We could take a look into that and see if we can add functionality there as well. And so where all this is coming from is our nginx service mesh. That's what we're working on at F5. So we embed Spire and deploy it as part of the service mesh, deploy the Spire server, the agent, and then we use Spire to manage all aspects of identity, MTLS, webhook certificates, API service certificates, secure NATs for communication, secure communication, sorry, secure control plane communication. We secure through NATs using certificates provided by Spire. So we built our service mesh using Spire as a first class citizen and all of identity and security through Spire. So that's my talk for today. So let me know if you have any questions. Well, I've got one. You mentioned on the last slide that the nginx service mesh is a Spire for all of its identities.  Good question, no, we don't run Cert Manager. And yeah, it was turning out that the only thing that we needed Cert Manager for was that webhook certificate. And yeah, I'm working and getting the stuff attributed to the Spire code base. We just use Spire for. Amazing. Now there's a question over there. Questions. Just a simple one, which is, have you done any scale testing with using Spire for doing the CA rotation or creating the CA? So questions, have we done any scale testing? No, what kind of scale are you looking at? I'm just wondering based off the way you say it behaves where when Spire comes up, it then generates CA bundles. I'm wondering how many of those can you do before you get to that three minute. Also the three minute timeout is for just when Spire delivers the certificate to the workload.  I mean, that hasn't been a problem for us. The testing that we did was just to see that we put like a short lifetime on the CA bundle and then to make sure that it keeps rotating. But we haven't done a whole lot of testing if we have like 5,000 webhooks or anything like that. We haven't tested it at that scale. That's a good, definitely a good suggestion, something we should look into. Shameless plug on that. On Thursday, I'll be giving a session with another community member on scaling Spire to one million. And they're running Kubernetes. So if you have questions like this, I highly recommend you attend that session. Great question then. Any others online or in person? Let me go ahead and say no. If any questions come in on the platform after the fact, we'll just drop them in slack. Thank you again, Faisalas was awesome.


Item number SCP-324 Object Class Safe Special Containment Procedures While SCP-324 does not require efforts beyond basic botanical maintenance to thrive, access to its products are to be strictly controlled to prevent theft and possible uncontrolled cultivation. SCP-324 is to be contained within a secure solarium or equivalent agricultural facility in a minimum of 5 cubic meters of soil. Soil should be maintained at a consistent pH of between 4 and 4.5 with a minimum 12% humus or similar organic compound component to topsoil. A misting system or other remote means of watering should be implemented to minimize the number of staff with access to SCP-324. SCP-324 is currently held at Site-23, Solarium-16, Bay 194, under these conditions. As on-site staff already have access to specialized botanical testing equipment and methodologies via the containment of SCP-38. Transfer of SCP-324 to another facility is subject to Level 4 approval. Products of SCP-324, designated SCP-324-1, may be transferred between research staff as necessary with Level 3 approval. To maintain SCP-324 is the only mature specimen during initial research. Attempts to cultivate further specimens from SCP-324-1 off-site are currently suspended. Description SCP-324 is a small evergreen shrub currently 1.4 meters in height and possessing a complex root system that extends approximately 2.5 meters below the soil. Leaves are lancelate, ranging between 4 and 6 cm in width. During the flowering phase, SCP-324 produces small 14 to 22 mm white flowers with 9 petals. Berries produced by SCP-324 are designated SCP-324-1 and appear pinkish-white in color with diameters between 9 and 14 mm. Berries are edible, with flavor reported as tart and mildly sweet. SCP-324's flowering and berry producing phase are apparently only initiated by the introduction of a deceased mammal of at least 25 kg into its soil. The mammal must be within range of SCP-324's root system and been deceased no longer than 3 days at the time of its first contact with SCP-324. If these conditions are met, the flowering phase will begin within 16 hours of introduction, with mature flowers in SCP-324-1 appearing within 75 hours. When eaten, each individual sample of SCP-324-1 will produce a vivid sensory experience, enacting a seemingly random memory of the deceased mammal's life in the consumer of SCP-324-1. In tests with human cadavers buried in SCP-324's soil, consumers of SCP-324-1 report clear oral and visual impressions, including specific locations, conversations, and individuals. The consumer of SCP-324-1 appears to experience the deceased's memory, as if it were one of their own, but recognizes it as a product of another mind. In tests featuring animal cadavers, consumers of SCP-324-1 report an overwhelming jumble of sensory input, devoid of the usual narrative context produced by human thought. Each experience lasts between 2 and 4 minutes before it subsides. If multiple samples of SCP-324-1 are ingested at one time, memories experienced proceed one at a time, each with the same 2 to 4 minute window. SCP-324 produces SCP-324-1 for approximately one week, regardless of the type or mass of the deceased mammal introduced into its soil. After this period has elapsed, all samples of SCP-324-1 wither and become inert, until another deceased mammal is accessed by the root system. Animals incapable of creating memories or lacking memories of their own, such as subjects of SCP-909, likewise produce inert samples of SCP-324-1. Discovery SCP-324 was discovered in a small cemetery, specializing in natural, coffinless and non-preservational burial in rural, county, New Hampshire. The groundskeeper, a Mr. Declan, would regularly transplant SCP-324 to the graves of the newly deceased and invite surviving family members to partake of SCP-324-1 for a substantial fee. The scheme was discovered inadvertently, when Agent- attended services at the cemetery for his deceased relative. Upon a demonstration of SCP-324-1's effects, Agent- immediately took both Mr. Declan, assigned D-Class and SCP-324 into Foundation custody. Mr. Declan claimed the shrub had been on the grounds when they were purchased in 19- and knew nothing further of its origins. Addendum Experiment logs 324-42.4 through 324-45.2 SCP-324-1 consumer Male D-Class Number 67531 Age 56 Soil input Human Female Aged 34 at TOD Deceased two days Experience report D-67531 placid for duration of experience Recounts an afternoon picnic from the perspective of a small female child, including impressions of flying a kite and eating a celery stalk with peanut butter and raisins. SCP-324-1 consumer Female D-Class Number 58563 Age 34 Soil input Chimpanzee Female Aged 44 at TOD Deceased three days Experience report D-58563 thrashes wildly for the duration of the experience, making gestures as if to ward off an attacker. Recounts impression of being assaulted by multiple individuals, uttering high-pitched squeals. SCP-3241 consumer Male D-Class Number 69965 Age 22 Soil input Human Female Aged 93 at TOD Deceased two days Experience report D-69965 uncooperative Restraints employed D-69965 force-fed SCP-3241 Continues thrashing for 43 seconds before abruptly relaxing. Eyes glazed for duration of experience. D-69965 drools slightly. Recounts staring out a window from a wheelchair at a busy urban street, sprinklers occasionally splashing the window. SCP-3241 consumer Female D-Class Number 39395 Age 42 Soil input Dolphin Male Aged 19 at TOD Deceased one day Experience report D-39395 holds breath for a duration of experience, passes out at 97 seconds. Revived Recounts impressions of swimming, darkness, pressure. Claims to distinctly recall speaking to another individual, but cannot remember content of conversation. Lesson complete. If you missed the previous orientation, go watch SCP-323 Wendigo Skull right now. Or for the complete course, watch this playlist.


What's going on everyone? Sam here with late in sports cards ripping one box of 22 Fanini honors football first off the line photo for Dylan out. So good luck here Dylan. That's so it's so funny because it's so random. That's like the best part. It's just you just got caught in the cross wire or something like that. I just uh god I don't know. Interesting. Hello. Hello. Hello there. I'm liking what I'm seeing here. I can't see it. Well I don't like that. I hate it. There's Jameson Williams to 75. J-mo. That's not Jersey number. No that is Jersey number. Nice. 18 of 75. There you go Dylan. And Purple Matt Stafford uh five of 12 to me. Excited to take that in Shry Donald. We've got a one of one Baker Mayfield on the iMac RPA for the Browns. Is your buyback nice one there again. That is one of one. I can't even I'm trying to find where they like stamped out the oh there it is. There's where they put honors on because they stamp every honors card with like an honor stamp so you can't just like take like a random card and put one of one and put it into a case. That makes sense. Yeah so I always try to look where they because I guess the serial number was up there. That's cool. And then we've got how about a Joe burrow. Three of five. Boom let's go Dylan. That's awesome dude. Big Joey B. There we go. My arch nemesis. But that is awesome. Big time burrow for you buddy. Let's go. Congrats Dylan. That'll do it for your break man. We'll get on right out to you.