Minusta on keskusteltu, että sieltä on tärkeää sääntä, johon on tärkeää assoissani, jossa sääntä on tärkeää assoissani. Joten järjestöä, että se on tosiaan järjestö, joka on tärkeää y-varmia, joten on tärkeää assoissani. Minä katsomaan esi-elmää 500-lipuksiä. Silloin varoittamme mennä koko ajan, ja mennään esim. Let's assume now that we want to make the claim that naming a woman as a CEO causes profitability to increase. So we can attribute this profitability difference to the women CEOs. Now why would this kind of causal claims be important? There are two reasons. First of all, causal claims allow us to make policy recommendations. For example, if we can make a valid causal claim, then we can make claims that we should increase the women CEOs. So with the more women CEOs we can make that kind of recommendations. Another important reason for making causal claims is that if we don't make a causal claim, then someone else will interpret our results causally. So when this difference was published originally in 2005, there were many discussions online on various newspapers and whether we should, based on this result, nominate more women as CEOs. Even let's take another example, there's a report that women-led companies are more profitable, it's not a unique observation to this particular study. Here's a report by Mackinsey. They showed that there's a difference between men and women-led companies. So women-led companies are more profitable and then they say that while this profitability difference doesn't allow us to make a causal claim, they nevertheless think that there should be a policy recommendation, that we have more women on boards or as CEOs. So what do you make of that? When someone reads that kind of claim that we can't make a causal claim, but nevertheless we think that there could be a good thing about more women-led companies, of course people will interpret that in order to improve your financial performance, nominate women to a CEO position. So people will make causal interpretations of your data. So you have to either make the interpretation yourself to guarantee that it's valid or you have to explicitly cause that it's not a causal relationship and you should refrain from making any policy implications like the Mackinsey people did. So how do we make a causal claim then? We have identified that there is a difference of 4.7% point and let's say that we have some way identified that that can be by chance only. So there is a consistent association that women-led companies are more profitable than men-led companies. How do we know that it's a causal effect? We have to ask the question of why is there a difference? We need different explanations to rule out, different theories to rule out alternative explanations. There is a reason for the correlation in the data, we just have to discover what is the reason. So is it the reason because women-led companies are more profitable than because of the CEO gender? Or is there some other reason that certain companies tend to be led by women and certain companies tend to be more profitable? To do that we need a theory. So the theory was a set of connected propositions or claims that explain what happens, how, when and why. So the important part in this example is that why are the return on assets between the men and women-led companies different? We need to have that white question. And a big part of doing quantitative research is to think what kind of rival or alternative explanations we have for our data. We have, for example, these explanations. We could say that women as a CEO causes firm performance, the first explanation, but it's not a direct effect. Rather it's that women facilitate top management team work and better top management team work lead to firm performance. Or it could be that smaller companies are more profitable and smaller companies are more likely to hire women. That would be an example of a spurious relationship. Or certain industries are more profitable, certain industries are more likely to hire women. For example, if we look at return on assets, mining industry, they have large assets. So the return on assets in that industry is pretty low compared to the mean of all industries. Then mining companies are more likely to be run by men than women. So that would be a reason to suspect that there's a spurious correlation. Or it could be a reverse causation. So we could say that because a company is profitable, they can afford to hire women. Or it could be that the women are better CEOs and that influences company performance. Why this kind of argument makes sense is because women are still discriminated against in CEO decisions. Only 22 out of 500 companies were led by a woman. That means that the last woman or the worst woman who gets to be a CEO in that sample is likely to be a lot better CEO than the last man. Because there are so many more men in the sample. So that would be that it's not actually that the women are better. Or there's something about being a woman that causes the company to be better. But it's a selection effect. So that's also a plausible alternative explanation. Then we need to consider which ones of these are the most relevant. Because we need to collect additional data. We need to have the variable for the CEO gender. We need to have the variable for the profitability. And then what else? We need to collect data to rule out these alternative explanations. And we would at least need the industries because that's easy to get. We would need the company sizes that's easy to get as well. These are top management team performance. That's more difficult to get. Skills more difficult to get. So it's a trade off of what is easily available and what we actually need. Then we start ruling out these alternative explanations. So we have to consider now three conditions for causality. And we can make a causal claim by showing that there is a statistical association between the cause X and the effect Y. That's the first step. The association may not be a correlation. It could be some other kind of association. But there must be an association. If cause and effect don't depend on one another, we can't make a causal claim. Then we would have to show that there is a direction of influence so that the X, the cause always comes before the Y, the effect and not the other way around. And then we have elimination of rival explanations. So how do we rule out the possibility of this correlation being an industry effect that influences the CEO selection decisions and also influences profitability? How do we know that it's not a firm size effect? There's a very simple strategy for ruling out the direction. And that is we just measure the cause before the effect. If we measure the CEO gender now and profitability the next year, it's implausible to say that profitability in the future caused the company to choose a women's CEO now. Of course there could be some profitability expectations that influence that, but that's a different thing. So we measure the cause before the effect. Elimination of the rival explanation is the hard part. We have two empirical strategies for that. And one is randomized assignment and do an experiment. In this case, we would take the 500 companies randomly assigned a randomly chosen finished man to half of the companies randomly assigned randomly chosen finished women to another half of the companies see which half is more profitable two years from now. That's of course impractical to do, but that's the experimental way. We manipulate the independent variable and then we observe the dependent variable after a delay. In practice, in business research, we do static system modeling or controlling for alternative explanations. We say that the company profitability is a function of a CEO gender plus some other things that could correlate with CEO gender. And then we test which one of those is the strongest predictor of performance taking the other plausible explanations into consideration.


Ladies and gentlemen, the story you are about to hear is true. The names were changed to protect the innocent. Dragnet is brought to you by Chesterfield. Made by Liggett and Myers. First, major tobacco company to bring you a complete line of quality cigarettes.  You're assigned to forgery division shoplifting detail. An organized gang of thieves has started operating in your city. In spite of the precautions taken, the thieves are still working. Your job? Stop them. Today's Chesterfield is the best cigarette ever made. It's the cigarette tested and approved by 30 years of scientific tobacco research. The cigarette proved highest in quality, low in nicotine, best for you.  If all adds up to Chesterfield's world famous slogan, they satisfy. Buy Chesterfield today, regular or king size. Just light up, relax, and enjoy America's most popular two-way cigarette. Chesterfield, they satisfy millions. Dragnet, the documented drama of an actual crime. In the next 30 minutes in cooperation with the Los Angeles Police Department, you will travel step-by-step on the side of the law through an actual case transcribed from official police files. From beginning to end, from crime to punishment, Dragnet is the story of your police force in action. It was Monday, September 20th. It was cold in Los Angeles. We were working the day watch out of forgery division, shoplift detail. My partner's Frank Smith, the boss of Chief Detective Stad Brown. My name's Friday. We were on our way out from the office, and it was 9.45 a.m. when we got to the eighth floor of the Whitfield Department Store. Security office. Yes, sir, can I help you? We'd like to see Mr. Dunlop. I believe he's expecting you. Your name? Joe Friday. Oh, yes. You want to go right in. Thank you. Thanks, Frank. The store here? Yes, go right in. Come on in. Hi, Jerry. You know Frank, don't you? Sure. How's it going? Hi, Jerry.  Thank you. I'll have the girls set up. Okay. Yes, sir? You want to have Miss Evans set up, please? Miss Evans, yes, sir. I'd like to ask you guys a favor. What's that, Jerry? For it to get things this whole thing is her fault. I'd appreciate it if you could take it easy on her. We'll do our best. Sure. What'd they get away with this time? Oh, here's a list. Thank you. Here's a copy for you, Frank. Oh, thanks. You got any idea when they were in? It's hard to tell for sure. We're open Friday night, and then Saturday's a pretty rough day. It wasn't until after closing we found it. I figured they either moved in late Friday night or early Saturday morning. Miss Evans' girl discovered the theft, did she? No, no, she didn't know anything about it. The stock clerk found it. He was running through the inventory to replace the coats and suits. Notice there were several that couldn't be accounted for. He called me. Evans' girl's in the department. I talked to her this morning. It looks like she waited on the pair. Is she able to come up with any kind of description? Yeah, I think she'll be able to help us. Oh, excuse me. Yes? Miss Evans is here. Will you send her in, please? Yes, sir. Come in. You wanted to see me, Mr. Dunner? Yes. Would you come in, please? Yes, sir. Oh, Miss Evans, this is Sergeant Friday and Officer Smith. They're from the police department. How do you do, Miss? Hello. I don't know why you want to see me, Mr. Dunner. I told you I didn't know anything about them. I told you. You've got to believe me. I didn't have anything to do with them. I never saw them before.  Thank you. Now, the officers are here to just talk to you. They want to ask you a couple of questions. There's nothing wrong. You mean I'm not going to lose my job? No. Really? You're not going to fire me? We never even considered it. I don't know how to thank you. My first job, and they have a thing like this happen. Sure. Appreciate it. Anything you want to know, I'll tell you. You just ask. I'll tell you. All right, Miss Evans. Have you any idea who might have stolen the merchandise? Well, didn't you tell them what I said, Mr. Dunner? Well, I thought it would be better if they heard from you. Oh, I see. Well, I think I know who they were. I've tried to remember all the people I waited on, everyone. There's only two that stand out, like they were different. How do you mean different, Miss? Well, they didn't seem like the other customers. You know, like they really wanted to buy something. They just wanted to look around. I could tell they didn't really want to take anything with them. We had a course on that in school. I had to tell if a customer really wanted to buy. Mm-hmm. That was one of the class problems, to sell a customer who didn't really want to buy anything. Yes, ma'am. About these people, what was it they did that makes you think they might have been the shoplifters? Well, first, the way they talked. I was trying to weigh on other people at the same time, and they kept me showing them all kinds of things. It took me almost a half an hour to clean up after they left. There were two people, is that right? Yeah, a man and a woman. Can he give us a description of them? I told Mr. Dunner all about it. You want me to go over again? I've got it, Joe. I'll try for you now. All right, fine. You want me to talk again? Well, we'll check it with you. Yes, ma'am. What kind of things these people want to see, ma'am? Just about everything at the counter. They had me some mixed up. I didn't know what to do. I told you I was trying to weigh on another customer. A woman who wanted to buy a suit, I kept trying to take care of her. She finally left. These two were causing so much trouble. Every time I left them, I couldn't even take care of the woman. She got mad and left. I don't really blame her. You know, Mr. Dunner, there really should be more people up there. Only three girls, and when we get busy, they're just on enough to go around. Lots of customers walk out. Mm-hmm. Well, we'll see what we can do. Lots of times they walk out without buying something, because there isn't anybody to help them. Mm-hmm. That's a woman who walked out. Could you describe her for us? You bet. She was real nice. Had a lot of patience. Kept waiting for me to go back and take care of the troublemakers. Never said a word. When can you tell us what she looked like? Well, I'd say she's about 35. It's hard to say for sure. She took real good care of herself. You know, her all nice and good makeup. Not cheap like. Nice hands and a manicure. Was she carrying any packages when she came in? Do you remember? Mm-hmm. Gee, I gotta think about that. I don't think so. Oh, you know, a couple of paper bags like from the Notions Department. Maybe face cream or clown. Things like that. No large boxes? No. I don't see why you're so interested in her. The other two were the ones who caused the trouble. They're the ones who must have taken things. Why are you asking about the lady? How was she dressed, do you remember? Oh, just beautiful. She had on a gray suit with large lapels. Kind of peplum that came out like this. Rhinestone buttons. Beautifully good taste. She wearing a coat? Mm-hmm. Had a stand-up collar, a real full skirt, tight bodice. Where was she looking at the suits? Over by the counter.  She knew what she wanted, looked at the material, the way they were made. She'd bought if I could just spend a little time with her. She liked the merchandise, liked everything I showed her. Mm-hmm. How many things did you take off the racks for? I guess she looked at a dozen styles.  That seemed to be all she was interested in. You don't think she had anything to do with the stealing, though, do you? Well, it looks like she was the one who did the actual taking of the merchandise. The other two were there to keep you busy. I can't believe that. She was so nice. Never seemed to get upset, even when I couldn't spend more time with her. Real nice. Couldn't get upset at all when she couldn't find what she wanted. I'm afraid you're wrong here. Hmm? She found it. We continue to interrogate the witness. We got complete descriptions of the trio, their physical appearance and their method of operation matched those of the gang Frank and I had been looking for for the past six weeks. Alice Evans was shown mugged shots of known shoplifters, but she was not able to give us an identification. We made arrangements for her to come down to the office and check additional mug files. The average citizen looks at shoplifting as a petty nuisance, which businessmen are expected to endure. This is not entirely true. Shoplifting is big business. Last year, hundreds of thousands of dollars worth of merchandise was stolen from stores in the Los Angeles area alone. Most of the goods stolen by organized gangs is sold to fences for final disposal. During the course of our investigation, we'd been working with Stores Protective Association incorporating all of the security officers in the larger businesses. M.O. bulletins had been gotten out on the gangs' activities and what we'd been able to find out there were three people working as a unit, two women and a man. The three suspects would enter a store and split up. One of the women would pretend to be looking at merchandise while the other two suspects would engage the clerk in conversation, in that way keeping her away from the first member of the trio. The articles stolen were almost always either coats or suits and we noticed that one line of merchandise seemed to attract the criminals more than others. Monday, 3.46 p.m. Frank and I went down to a second-hand clothing store on Fifth Street to talk to the owner. You're right way there. Toby? Yeah. Hi, fellas. What's going on? Oh, we got some things we want to talk to you about, Toby. Sure, just having a cup of coffee in the back.  Fine, thank you. In here? Yeah, sit down. Get yourself together. Thanks. Anything special? No, we're just fishing, Toby. Thought you might be able to come up with a little something for us, maybe. And here you go. Do you want some sugar? No, no, thanks. Don't use it. Just doing part of your work here. All right. Yeah, buy sheets. Want to get in the mail tonight. Well, we don't want to keep you, Toby. Yeah, no trouble, Sergeant. Max, get a little tired anyway. Just stop and have a cigarette. How's business? Pretty good. Keep it up. Now, what can I do for you? You got anything on a boosting gang working around? Nothing more than usual. Why? Well, we got a bunch that's giving us a little trouble. We're trying to come up with something a little hang together on them. Two men and a woman? Yeah, you got anything on them? No, no, no. I'm just eating. Rumbled around about the three of them. That's about it. I had them all right. I called you sooner. Where's the information coming from? You know how it is, Sergeant. You hear something here, something else there.  Yeah, I know. You got any idea where the stuff is being sold? Same answer. Rumble's got it that all the loot's being shipped out of town. Some to back east, some goes up north. I got a piece the other day that some is going to Mexico. Mexico, huh? Yeah, most of it's ending up in the east, though. You know any reason they'd be hitting at all? What's that? The gang's laying it out around town that they'll pay up to 25 bucks for a suit. You know, going price is around five, maybe six and a half. Figures that if you can do better with one line, that's what you're going to boost. Why's the price gone up? Yeah, the only way I can figure it is that they're worth more in the market. Anybody approached you? If they had, you'd have been called right away. You know that. You got any idea where you might be able to pick up anything on the trail? Not right out, but I'll tell you a man's a gun. He sets up the deals, makes a shipment. How do you get in the stuff out, Toby? Do you know? Pick up the kid and offer him a trip. Ask him to deliver a suitcase. Works out good for him. Carrier doesn't know who he's working for. Can't lead the cops back to the operation. About the only way I can figure it. You saying none of the stolen stuff showing up down here? Nothing so far. Well, thanks a lot, Toby. If you hear anything, we'd sure appreciate a call. Sure thing. Real good coffee, Toby. Instant. Coffee by? Habit, I guess. Well, thanks again. We won't keep you, Toby. Oh, hang on a minute. All right. Yes, sir. What can I do for you? Buy used clothes. Yes, sir. What have you got yourself? That's in the car. I just want to be sure you're buying stuff. Well, bring it in. We'll take a look at it. Okay, Toby. We'll see you later, huh? Right, Sergeant. Give me a call. Right. I'll be right back. Excuse me. What do you think of that, Sergeant? Sure in a hurry, isn't he? Yeah. Right up there. Hey! Hold it up there. Huh? What do you want? It's nothing. Didn't you hear me? I asked you to wait back there. Well, sure I heard you. I didn't know you were talking to me. What do you want? Police officer. I want to step over the car. I want to ask you a couple of questions. Well, I haven't done anything. You didn't say you did. Well, why do you want to talk to me? What do you want me to come up with? Come on, let's go. All right. I'm making a mistake. I haven't done anything. Mm-hmm. Got the wrong man. You've got no reason to talk to me. All right. Get in. What are you doing? You won't find anything. I don't know what you guys are after. I haven't done anything. Take your wallet out. Why? Take it out. Here. Take the money out of it. You always carry that much money, do you? No, not always. I know. You keep the money in your hand. Give me the wallet. Here you are. Is your true name? Hmm? Kenneth Elgin Norris. Is your right name? Yeah. You live here now, do you? No, not now. Where do you live? I got a room over on the 7th. You want me to run a make on it? Yeah, will you? Here. One K-80 to control one. One K-80 to control one. Control one to one K-80. Go ahead. Check for one. Kenneth Elgin Norris. That's N-O-R-R-I-S. Male white American. 26 years. 5 feet 10 and 3 quarters. 168 pounds. Black hair, brown eyes. K-M-A-367. One K-80, Roger. Stand by. What's all that about? Checking to see if you're one of them, please. Oh. You ever been in trouble? Me with the cops? That's right. No, never. What's all that about? Checking to see if you're one of them, please. Oh. You ever been in trouble? Me with the cops? No, never. Why'd you leave the clothing store in such a hurry? I remember I had a meeting guy. I remember I was late. Who's the guy? A friend of mine. You wouldn't know. Well, try us. It's a guy named Arthur. I don't know his last name. Where were you going to meet him? A bar down the street. What about the clothes you wanted to sell? What about it? Where are they? I don't know. Well, you went in to sell something that you didn't have. Is that it? Well, I was going to pick him up from Arthur. You don't know his last name? No. How come you were going to sell the clothes? Huh? Why were you going to sell the clothes? That's a silly question. I think because I needed the money.  Well, I got to leave town. I'm selling all my stuff. I thought Ted, the clothes belong to this Arthur guy. Well, they do. But I'm going to sell them for him. He said he'd give me a piece of the profit. Why doesn't he sell them himself? Well, I don't know. You better ask him. We'll try to. I'll get the rest of the stuff out of your pocket. Come on, everything.  You know that, don't you? A real big mistake. Well, if we're wrong, we'll tell you. Yeah. Here it is. Comb, change, cigarettes, and a lighter. That's all there is. You sure? Well, why would I lie? Turn your pockets inside out. What? Turn them inside out. All right. All of them. The other one, too. Told you, I gave everything I had. There isn't anything else. What's that? Huh? Move your foot. What's this? Looks like a key. What's it for? Well, I don't know. It isn't mine. Maybe it belongs to Arthur. It could be. It isn't mine. Looks like a check locker key, doesn't it? Might be. I never saw it before. Came out of your pocket, didn't it? No, it didn't. Must have been on the floor all the time. It isn't mine. Thought you said you'd never been in trouble. I made a mistake. Looks like you made more than one, doesn't it? What? Maybe you were wrong about the locker key. I told you. I never saw it before. I'm sure. You want to sit with them, Frank? Yeah. I'll get to a phone. All right. It's just a key. What is that proof? I don't know. Let's find out what it opens. We got the location of the locker.  The locks on the case had been broken. And inside, we found 11 women's suits of the same type that had been stolen from the Los Angeles stores. All identifying labels had been removed, but we were able to find the tag issued by the National Recovery Board inside the seams of the suits. We got in touch with their Los Angeles office, and they told us that the serial number had been issued to a San Francisco company. On the way back to the city hall, we stopped and searched the suspect's room thoroughly, but we found nothing. When we got to the squad room, Frank went to the business office to arrange a phone call to San Francisco, and I took the suspect to the interrogation room. 6, 20 p.m. You guys got to believe me. That stuff's not mine. I don't know where it came from. Where'd you get the key? I never saw it before. That's kind of hard to buy. I don't care if you want it or not. That's the way it is. Tell us a little more about this, Arthur, will you? I told you everything I know. Where'd you meet him? In a bar down on Maine. I told you that before. Now, what's the matter? Don't you believe me? You're making it tough to believe. I'm telling you the truth. Where'd the suits come from? I don't know. All right, here. Take another look at them. It might help you remember, huh? They went to the suitcase when Arthur gave them to me. That's all I know. Where'd he get them? I don't know. He steal them? Well, I don't know. He told us before he wanted you to sell them, didn't he? Well, he did. Where were you going to make the payoff after they were sold? He said he'd get in touch with them. Where? Around. He said he'd find me.  That's right. When? Sometime. He didn't name a date? No. He just said he'd look me up. How many times have you been arrested? You got the record? Why are you asking me? He wants you to tell us. I don't know. I forget. We'll take a guess. A few times. Five? You got the record? When's the last time he checked with your parole officer? I forget. No, I didn't know until I heard on the radio. You had no idea, huh? No. You went up for burglary, is that right? Yeah, they sent me up to the joint. You know you're going back, don't you? Yeah, I guess. It's not going to look good to have another charge marked on you. What do you mean? Burglary. Why'd you dig that one up? These suits, if you can't explain them, it isn't going to look too good, is it? Look, I told you Arthur gave them to me. And he said he'd get in touch with you. Yeah, that's right. Sure. Come up with the answers, yeah? Says he doesn't know them. Yeah? Maybe we can help, hmm? Just got through talking with a Georgia writer up north. Yeah. He checked the records. Code numbers from the shipment to the Whitfield department store. Looks like the bunch we're after. Now, who's Arthur? You mean the suits were stolen? You called it. Who's Arthur? Look, I don't want to go back to the joint on a beef like this. We don't decide that. But if I help you guys, you'll take care of me. You'll talk to my parole officer. I can't make any deals with you. Yeah, but I don't want to fall this way. That's up to you, mister. You're sitting in the middle. Now, which way do you want to go? Nobody can help you but yourself.  Might be the way you figured it. What's the matter? Doesn't Arthur like you? Okay, I'll go the route, ma'am. I'll tell you where to find him. You are listening to Dragnet, the authentic story of your police force in action. You hear it everywhere. Chester Fields for me. Here's how lovely New York model and television star Roxanne puts it. I started smoking Chester Fields about the time I got into show business. Yes, it's Chester Fields for me. I like the regular size. Now let's hear from the man who owns and runs the store club, Sherman Billingsley. You know it's my privilege to be a host over 4,000 very nice people every day. And most all of them smoke Chester Fields. As a matter of fact, our records show that Chester Fields is our largest seller, 3 to 1. And it's Chester Fields for me. I like them king-sized. Either way you like them. Chester Fields regular, Chester Fields king-sized.  Always say, Chester Fields for me. We called a stenographer and Kenneth Norris gave us a complete statement. He said that he'd been approached by a man that he knew only as Arthur and asked to carry a suitcase to St. Louis. Once there, a man would have him paid at the airport and take the valise from him. In return for this service, the suspect was to be paid $100 and his expenses. Norris explained that he decided he could do better by selling the contents of the suitcase himself. This information was forwarded to the St. Louis Police Department. We got a complete description of the man he knew as Arthur and had the suspect checked through the mug books but he wasn't able to make an identification. We got in touch with his parole officer and told him that we had Norris in custody. We asked that we be allowed to detain him for a few days. The following morning we met with Chief of Detective Stad Brown and Captain Welsh. We decided that Norris would take us to the bar where he'd met the thief and he'd point him out. Norris would then be brought back to the main jail and booked and I would try to establish myself with this Arthur. In that way, we would have a better chance of building a case that we could take to court and apprehending the entire shoplifting gang. On Wednesday morning, September 22, Norris, Frank and I drove over to Main Street. We checked the bar but the suspect wasn't there. We waited in our car which was parked down the street. Arthur failed to arrive. He didn't show up at the bar on Thursday or Friday. Saturday, 12.40 p.m. Norris pointed down the street. There, that's him just going in the place. Fell in the gray suit there? Yeah, that's him. You sure? I got no reason to lie, have I? All right, Frank. You want to take Norris back to the office, I'll go on in. Okay, I'll be right back. All right. Sergeant? Yeah. I'll give you something for free. Yeah, what's that? Take it easy with Arthur. Don't press. How do you mean that? He's a pretty rough guy. That's all. Yeah, I hear he carries a gun. He'll out of trouble if he's got it with him. Not unless he tries to use it. I left Frank at the curb and walked into the bar. I saw the man that we knew was Arthur sitting at the rear of the place. I took a seat near the front door in order to cup of coffee. In a few minutes I walked back toward Arthur. Something you want? Yeah, I wondered if I could have one of your cigarettes there. There's a machine up front. If I had the price, I'd have bought a pack coming in. All right. Here. Got a match? How you fix for a breath? Look, I just asked you for a cigarette if you don't want to give me one. Say so and I'll shove off. Never mind. Here's your match. Thank you. Hey, you. Yeah?  All the way. Just getting town this morning. Where from? Up north. Up down. Look, mister, here's your cigarette bag. Give me one of these. Doesn't entail you about my life story. You hungry? I haven't eaten for two days. Here. Thanks. Appreciate this. How long are you going to be in town? Well, it depends on how things work out. You got a job? I'm going to look. What do you do? Whatever pays. Tell you what? Well? I got some friends around town. Might be able to use you. Check with me in a couple of days. Might be able to do something for you. How do I get in touch with you? Meet me here. I tagged the place a couple of times a week. Just to ask if Arthur's around. What's your name? That's what I'm using this season. If you look me up, kid, we'll work something out. Yeah, I'm sure we will. I sat and talked to Arthur for another half hour. During that time, he wouldn't tell me his last name, and I had no way of finding out anything more about him. At 1210, I saw Frank drive by the front door. That was the signal that the crew of detectives were standing by to follow the suspect. I left the bar and walked down Main Street up to 7th. Frank was waiting for me. We drove back to the city hall and discussed what had happened with Chief Brown and Captain Welsh. During the next three days, Arthur was kept under constant surveillance. He didn't drive an automobile. He contacted no one. We were able to learn a considerable amount about the man. Although he didn't try to make contact with any other members of the gang, it was obvious that he was the prime fence and that he was directing the operation. Wednesday afternoon, I walked into the bar on Main Street. Arthur wasn't there, but the bartender said that he was expecting him. I waited. At 647 p.m., the suspect entered the place. He took a seat at the rear of the bar and motioned me back. Hi, I've been looking for you. You're all right. Yeah.  I can sure use a touch. You like to travel? What? I think you might have something for it. You've got to go out of town, though. For dough? I wouldn't ask you any other way. Well, what do I have to do? A friend of mine has a suitcase he wants delivered to a party in Chicago. Why didn't he send it by mail? He doesn't want it to go that way. He wants it delivered personally. Well, what's it pay? All your expenses, $100. What's in the suitcase? It isn't any of your business. What happens if I get picked up? I don't even know I'm not carrying anything hot. You've got to take my word for it, James. All right. Who do I deliver the suitcase to? I'll meet you in the morning. I'll give you the bag then. You've got your 10 o'clock plane. When you land at Chicago, go to the coffee shop. You'll be paged. Meet the man and give him the suitcase. Well, I know if it's the right guy. We'll give you the name.  All right. Where do I meet you? Be out in front of this place at 8 in the morning. I'll pick you up. Just one more thing. How about the money? You won't need any going back. When you turn over the suitcase to my friend, he'll give you the 100. You already have your ticket. All right. Sounds okay. Not as permanent as I'd like.  We'll be able to do more business. I'll meet you here then at 8 in the morning. Is that right? Right. Be on time. I don't want you to miss that plane. That depends on this deal. I don't want anything to go wrong. Now, don't worry. What? I left the bar and met Frank. We stood with the front of the place and at 9.56 p.m. the suspect came out. He called a cab and we followed him. He went out to the apartment where we knew he lived. Frank and I waited out front. At 11.20, a car pulled up in front of the place and three people got out. They matched the description of the thieves and our shoplifting operation. They were carrying a large suitcase. We waited for 10 minutes and then Frank and I went up to Arthur's apartment. Number 408. Uh-huh. Down this way. Uh-huh. I'll get the door. Wait a minute. All right. What are you doing here? What's this all about, all right? Police officers, you're under arrest. Stand still. A cop, a lousy cop. I should have known. I thought I could trust you. I thought you were honest. Tell you, sure pick him a cop for a message, you boy. You're real smart. I thought I could depend on him. I thought he was honest. You don't know what the word means. How about it, mister? Huh? Do you? Story you've just heard is true. The names were changed to protect the innocent. On January 18th, trial was held in Department 97, Superior Court of the State of California, in and for the county of Los Angeles. In a moment, the results of that trial. Now, here is our star, Jack Webb. Thank you, George Fenerman. You know, the Chesterfield you smoked today is the best cigarette ever made and best for you. Now, that's a fact. And to my way of thinking, it's the very reason for you to change to Chesterfield. Try them either way, regular or king size. If you try them, I think you'll say with all of us, Chesterfield's for me. Arthur Nelson Thompson, Samuel Donald Hickock, Georgia Baxter Nielsen, and Dorothy Marie Simpson were tried and convicted of burglary in the second degree, 14 counts. They received sentence as prescribed by law. Burglary in the second degree is punishable by imprisonment in the state penitentiary for a period not less than one, nor more than 15 years. Ladies and gentlemen, we'd like to thank the editors of Cosmopolitan Magazine for this month's pictorial feature on Jack Webb and Dragnet. Cosmopolitan, the May issue, on your newsstands tomorrow. You have just heard Dragnet, a series of authentic cases from official files. Technical advice comes from the office of Chief of Police W.H. Parker, Los Angeles Police Department. Technical advisors, Captain Jack Donahoe, Sergeant Marty Wynn, Sergeant Vance Precher. Heard tonight were Ben Alexander, Jack Krushan, Alice Bacchus, Ralph Mooney, Herb Ellis. Script by John Robinson. Music by Walter Schumann. Hell, give me speaking. Watch an entirely different Dragnet case history each week on your local NBC television station. Please check your newspapers for the day and time. Chesterfield has brought you Dragnet, transcribed from Los Angeles. Filter, cigarette smokers. Here is headline news. Nationwide demand for L and M filters drops price. Now you save up to four cents a pack, 40 cents a carton. Now everyone can afford America's highest quality and best filter tip cigarette. Remember only L and M's have the miracle filter tip containing alpha cellulose. You get much more flavor, much less nicotine. Buy L and M filters, the distinctive monogram cigarette at the new low price. L and M filters. Here are crime and Peter Chambers following John Cameron Swayze on the NBC Radio Network.


now have to answer that question as to, you know, whose name, you know, Peter and John ministered to this lame man. So Peter and John, they are bold enough, Peter being filled with the Holy Spirit, answers that question and tells them that they did it in the name of Jesus. So next, what happens from verse 13? I hope you're able to track with me. I'm reading some of these scriptures, you know, so that it'll be easier for you to understand. If I just narrate the story, you might miss out on some keywords there and all, but I hope it's not confusing. Is it okay? Okay. All right. So the best thing to do is to have the Bible open in front of you as I talk and look at the Bible. That is what is going to, you know, be the best way. But if you're just listening, I think that also should be fine, because I'm reading out some of the scriptures here. So yes, I'm at verse 13 of Acts chapter 4. So you can imagine the scene with me. Here are these leaders and they are, like they are just, you know, blown away by the answer of Peter and John. They would have wanted them to, you know, be covered Lee and try to, you know, cover up some matters and, you know, come across as really fearful, but they were bold enough. And they said they ministered in the name of Jesus. So when the authorities observed this, scriptures say, when they saw the boldness of Peter and John, and you see how they're able to process it, these guys are so bold. How could they be so bold? And Luke goes on to write and perceive that they were uneducated and untrained men. Okay. Standing up in front of a learned audience, boldness comes when you have done this many times before, you've been trained, you probably educated, but these guys had none of that and the panel knew it. So they knew that the caliber of these men is they are untrained, they are uneducated. So what is the reason? They marveled, it says, look at them and they marveled and they realized that they had been with Jesus. So you see, they're already witnesses of the life and the ministry of the Lord Jesus and they knew, you know, what kind of a man he was and looking at Peter and John and their boldness they were immediately able to make the connector.  So they're just like Jesus. They had been with Jesus and that boldness rubs off on his disciples. Wow, what a wonderful testimony, isn't it? That somebody looks at us and they look at our, you know, life, they hear our testimony, they hear what we have to say and they are marveled. They say, how come this person has this wisdom or has this boldness and they come to the conclusion they had been with Jesus? Okay, so it really challenges us in our walk with the Lord and, you know, let's pray that we can be witnesses of this kind where people will immediately know that these people have been with Jesus. Okay, verse 14, seeing the man who had been healed, standing with them, they could say nothing against it. See, I've been saying that the miracle speaks for itself in many ways. So how can the authorities do, you know, any further? They are interrogating, intimidating, all that they're trying their tactics, but there is nothing solid that they can convict these men with. What will they convict them with? Peter also said, we did a good deed.  What are you saying? Is that why we are under trial? So the authorities knew all this, that they really had no grasp on, you know, any solid point. So now what to do? They're stuck. The authorities are stuck. They can't do anything. So finally, what conclusion can they come to verse 15? But when they had commanded them to go aside out of the council, they comfort among themselves. Okay, this is panic mode, crisis mode. They may be influential people, but they comfort together. So you can imagine, okay, you can imagine. Here's the room and the whole trial is going on. And the authorities feel stuck. So they tell Peter and John, can you go out for a few minutes? I don't know, we have to talk. And then you can see what this Peter and John have gone out. They're like, okay, now what to do? What is the best thing to do? So they're having like a conversation among themselves to manage the situation. So they comfort among themselves, saying, what shall we do to these men? For indeed, that a notable miracle has been done through them is evident. So they are affirming. It's a real miracle to all who dwell in Jerusalem and we cannot deny it. How real is it? Everybody in Jerusalem knows this man. And now they can see he's walking. They can't do anything. Okay, it's out of our hand next 17. But so that it spreads no further among the people, let us severely threaten them that from now on, they speak to no man in this name. So this is the best they could do. They were like, we have no proper evidence. Our tactics of intimidation is not working on these men. Okay, let's do this. Let us threaten them. And we will instruct them. I will tell them, you should never again speak in this name. You do what you want. But we don't want to find you anywhere speaking in the name of Jesus. So they thought this is the best solution for now. We'll see how it goes. Okay, so they came to this conclusion. What happens next? They called them and they commanded them not to speak at all, not teach in the name of Jesus.  Okay, that's what they told them, the disciples. Can the disciples obey? Now, what do we do when the authorities tell us not to fulfill the great commission, talk in the name of Jesus? What do we do when we encounter such situations? Let's see the example of Peter and John. Peter and John 1st 19, they say, they answered them, whether it is a right in the sight of God to listen to you more than to God, you judge. So obviously, they are not succumbing to the pressure and they are not willing to give up and say that, okay, fine, we will stop preaching in the name of Jesus. Oh, we are so scared. What will happen to us? No, but they knew that the God they served is greater, just like Jesus. It's like they tried to contain one Jesus, but now you have many others just like Jesus and they're not able to control what's going on and the boldness remains. So Peter and John, they say, we're sorry, we cannot do what you're asking us to do. We have to stand up for what we believe. We are witnesses of the Lord Jesus. So they counter question them. Okay, you asked us all these questions and now you're commanding us not to preach in the name of Jesus. Here's our counter question, whether it is right in the sight of God to listen to you more than to God, you judge, you decide. How can this is the same God you claim to worship? And we are following that God and you're asking us to stop. So it's not fair. That's the point they were trying to make. So verse 20, for we cannot but speak the things which we have seen and heard. So they are simply saying, we will be witnesses. You can't stop it. Whatever we know till now, whatever we have seen till now, we are going to continue to share it and you can't stop us. Okay, so they told, come under the pressure. So at times when authorities ask us to do things which will make us go against what God has spoken. Or let me put it this way, against worshiping God. Yes, there are some, a few things which, you know, if we are told, okay, don't worship in this space or don't make too much noise or don't fight. You understandable, very reasonable requests. You can follow those things. But if it comes to a place where like in the case of Daniel, he's told, oh, you need to bow down. You cannot worship your God. You have to bow down to, at that point it was the idol of the book of Nazareth. He says, no, I'm sorry, I can't do it. So right now, the disciples are doing the same thing. They're saying, we cannot but speak of the things which we have heard and we have seen. So we will continue to be witnesses. So they tell them boldly and verse 18, okay, we've already done verse 18, verse 21. So when they had further threatened them, so further threatened means it's been a hard time for Peter and John. They have been threatened earlier. They have been threatened prior to this. So they continue to face opposition through this entire trial and the authorities are clearly instructing them. They're commanding them. Don't speak. Just don't speak in the name of Jesus and they let them go, finding no way to punish them because of the people since they all glorified God for what had been done. I know that your batch has completed the course on keys to supernatural ministry and how over there we said, why is the supernatural important? Because it turns the hearts of the people towards God. So notice here, even the authorities recognize that the people are glorifying God because of what had happened. So when miracles take place, when supernatural things take place, what is the outcome of that glory to God? So we must pray and ask God that all these things happen in our midst today. So they are commanded, they are threatened and they are let go. Okay, so yes, again, there's that explanation that it was a notable miracle for the man who was over 40 years old on whom this miracle of healing had been performed. Okay, now let's see what kind of reaction Peter and John would have. Something has completely changed in the dynamics. They are so bold compared to the times of the trial of Jesus. So Peter and John, they are let go. They went to their own companions. Again, it's so beautiful. See, when we are going through a time of persecution, a time of opposition, these are all not things that we can face alone. Okay, so thank God, because the word of God talks about the church, it talks about community, it talks about coedonia, the fellowship of believers and Peter and John had such a fellowship.  These are the believers. Are the believers who are in the upper room? They are the believers who accepted Christ on the day of Pentecost and we don't know. As the ministry is going on, we are only hearing about the ministry of Peter and John. There were other apostles, there were other believers. They would have gone and spoken to people. So there could be others as well.  But the message is spreading in Jerusalem. These folks, Peter and John had their own companions. So they had that gathering that I was mentioning about for those 3000 people plus 120 at least. So they come back to some of these people, they come back to companions and do what they shared. They unburdened their hearts. They told that they reported all that the chief priests and the elders had said to them. It would have been a painful experience but thank God, that was the fellowship of the believers. They came back and they were able to share, they were able to report. Look, all this has happened. Why? Why do you think it would have been helpful to share? For several reasons. One is they would have found comfort in those companions. They would have just been able to release the, if at all, atmosphere or anxiety, whatever they were carrying and they could rely on the prayers of the others. So while there are some in the forefront facing the fire, there are others in the background upholding these men in prayer. They are also battling in the spiritual realm when times of opposition come and times of persecution come. So that is the beauty of this. So they go back to their own companions and they report. So we can expect probably this companion, this group of believers will get scared. They will be disturbed and they might come to the conclusion that, or they might try to convince Peter and John, what have you done? You should have just said, okay, we will no longer preach in the name of Jesus. We will preach in some places, but they don't notice us. So they could have given such advice also, but that was not the case. Verse 24, what happens when they heard that, they heard the report, they raised, they raised just all these people, the fellowship of believers, including Peter and John, it says, raised their voice to God. So prayer is rising up. So moments of great opposition, there is a need for prayer and even prayer in groups and communities, it says, they raised their voice. Isn't that interesting? They raised their voices. That would probably be like Acts 2, when they were all gathered and they were all praying together. So there would have been, I mean, there was a sound and people gathered because of lots of voices. But in this case, Acts 4, they raised their voice, one voice. So one voice, we can understand it in several ways. Maybe one person prayed aloud, but the hearts of the others was very much in line with that one person. And so the voice of that one person is the voice of every person gathered in that meeting. So it just goes to say there was unity of heart. Remember, we said that was one of the beautiful features of the early church, the oneness, the unity of their hearts. And you see that even at a time like this in difficulty. So they have one voice to God or together they are asking God, the same things. It's not like some believers have a few points which are pulling in the opposite direction of the points of other believers. Unity of thought, unity of mind, unity of heart. So they cry out to God and it also adds as if one voice was not enough. Luke adds, he says, with one accord, one voice to God and with one accord. That's a beautiful fellowship, oneness of heart. They call out to God. Okay, so what could their prayer be now? Let's see. They are saying, so whoever prayed on their behalf, Lord, you are God who made heaven and earth and the sea and all that is in them. So they are beginning by affirming the nature of God, the capacity of God, the greatness of God, the majesty of God. So no, they just getting perspective.  We worship the God who has created the heavens and the earth and they're affirming that and by the mouth of your servant David have said, the quoting from Psalm 2, why did the nations rage and the people plot vain things, the kings of the earth took their stand and the rulers were gathered together against the Lord and against his Christ. So the opposition reminds them of what the psalmist wrote. Why did the nations rage? So why did opposition rise up against who? Notice again, they are not saying that, at least in the beginning, they're not saying that we have encountered opposition. But the context here is, this is a plot against you, oh God, against the Christ. So just give me a moment here. I would like to pause and also just reconnect my system here. It's sort of losing the power. So I'll just reconnect it and be back with you in a minute. Okay, my apologies. Let's go back. Yeah, so I was saying that they did not take the opposition as just opposition that came against them. But they understood that this was a spiritual opposition, just the way the opposition came against Jesus today when they are ministering in the name of Jesus, they're also facing opposition. And remember Jesus said that when he taught his people, he said, if they did not spare the leader, the master, how would they spare the followers? So it was happening. Everything that Jesus talked about was actually beginning to manifest in the lives of his followers. So let's go forward verse 27. Truly against your holy servant Jesus, whom you anointed, both Herod and Pontus Pilate, with the Gentiles and the people of Israel, were gathered together to do whatever your hand and your purpose determined before to be done. So basically they're stating facts, whatever happened in the life of Jesus, his trial. But they also say that God, your purposes were accomplished anyway, no matter what man tries to do, God is powerful enough to accomplish his own purposes. And verse 29, knowing all this, knowing that God is mighty, knowing that this kind of opposition had come against Christ and as followers of Christ, they're facing the same thing. Jesus went through it, they're asking for God's intervention. What do they ask for? Are they asking God protectors, God put us in a new city or harm the rulers? Sometimes we hear prayers like that. Yes, be led by the Holy Spirit. We're not saying every time somebody is facing persecution, you have to pray only like this. No, you pray as the Holy Spirit leads you, but this prayer is very encouraging to us because what they ask verse 29, they say, now Lord, look on their threats and grant to your servants that with all boldness they may speak your word. So as boldness throughout this passage filled with the Holy Spirit, Peter says to them and now again in prayer, in unity, they are telling God, God, whatever boldness we had till now, let it continue and give us Lord, give us all boldness, they say, that give us meaning the apostles in this case because at that point they were the primary leaders of the church. So they were the ones who would stir things for all the believers. So they're asking, the people are also praying for these apostles and in this case, more specifically Peter and John and they're saying, God, give them the boldness, give them that they may speak your word, nobody can stop. The word of the living God of heaven and earth, let nothing intimidate us, help us to keep doing what you have called us to do. So I'm just reminded at this point, there are many stories that we can talk about, but I'm reminded of the story of Richard Wumber and those of you who have read and I probably have quoted, talked about him earlier in God's underground. He said story of a Christian who was put in the communist prison for his faith, but it's beautiful because once he got saved, he developed the habit of memorizing scripture and in the prison, he was so moved by the power of God or the spirit of God to continue to share Christ and you see how difficult it is to share Christ in the prison. You're in your own cell, how can you even talk about Jesus to someone else, but the beauty was he had scriptures inside him, so in the prison, they say more scored and some such things where you can communicate with tapping. So he would do things like that to share the gospel. Can you imagine, you don't expect somebody who is persecuted, being persecuted to be bold enough to continue sharing the gospel, but somehow we see when people are standing up for Christ in the right way, sincerely and opposition comes, nothing can intimidate, nothing can stop the work of God and the book of Acts is a great example of how persecution, it's just starting by the way as we go into the coming chapters, there'll be more persecution, pretty scary stuff, but did that stop the gospel? No, did that stop the saving of souls and people being added to the kingdom of God? No, it only multiplied, it continues to multiply, so that thing can stop the purpose of God and that's what they prayed also in this prayer, they said, God, you're not afraid, they tried to crucify you, they tried to stop your process, but yeah, they tried to stop your purpose, but nothing stopped Jesus, your purpose was anyway fulfilled, even through us, your purpose will be fulfilled. So what do they ask for? They say, God, you know all the threats, grant us all boldness, especially the leaders so that they may speak your word. Can we pray like this for people we know who are facing persecution right now? Yes, we can pray for our brothers and sisters and say, God, you give them your word, boldness to speak your word in the very circumstances where they are at. Second thing which they're asking was 30, they're saying by stretching out your hand to heal and that signs and wonders may be done through the name of your holy servant Jesus. Okay, again marvelous, one miracle which took place, you're in trouble, we're already in trial Peter and John, but what are the people asking for? They're saying, God, do more. Hello, wasn't this enough? We've already faced the fire, no, because they also had this boldness that nobody can stop God. Let them try, let them try all they want. We have a mandate, we are witnesses with power for the gospel, we are witnesses with power about the resurrection of Christ. So let them do what they want to do, we've got to do what we've got to do. So they are bold, they're asking for the word to go out and the miracles too, we continue among their midst. So how does God respond? We pray, sometimes there are physical manifestations where we can say, I felt peace, I felt the warmth of God on my body, I felt like a cool breeze, something tangible that we can point to and say, I know God answered my prayer. Not always though, we don't have such things happening all the time. In this time when the believer spread something tangible to place, verse 31 it says, and when they have prayed, a place where they were assembled together was shaken and they were all filled with the Holy Spirit and they spoke the word of God with boldness. So somehow, you know, God thought it fit to give them these physical manifestations of his presence. Earlier we said a sound from heaven rushing mighty wind. So it was evident, hey, God is here, God is ministering to you guys again when they are in this place physically, the place where they were was shaken. Some translations, they kind of point to an earthquake. So an earthquake took place. As if to tell them, I heard your prayer. So don't ask me why earthquake, why not rain, I have no idea. God just wanted a way in which he wanted to show that I'm with you. And I've heard your prayer.   So their prayer is answered in a way right at that moment. They are speaking God's word with boldness. It doesn't feel like they lost their mandate or their agenda or their great commission despite the opposition.  So notice baptism in the Holy Spirit for the first time happened on the day of Pentecost. So we also stated being born again is a separate experience from being baptized in the Holy Spirit. And all believers in the book of Acts, you will see first they accept Christ, next they will be led into baptism in whatever baptism in the Holy Spirit once. So once it happens. But that is just the beginning.  So baptism in the Holy Spirit, the initiation of it is, you could say, yes, I'm baptized in the Holy Spirit that speaks of that first experience which you've had, I've had. But that's not all. There can be multiple and repeated fillings in the Holy Spirit, which you and I can have. So don't stop at the day of Pentecost. Time and again, day in and day out, no wonder Paul later wrote, he said, you know, walk in the Spirit, be filled with the Spirit, okay, bear the fruit of the Spirit. So we can have these multiple fillings of the Holy Spirit resulting in what? Resulting in, as we've seen, boldness, science, miracles, wonders, wisdom of God, the fruit, the nature of God being seen through us like Jesus, becoming more like Jesus. So the point I'm making is we have to desire filling of the Holy Spirit. Don't be satisfied. Oh, on the first time when I was baptized in the Holy Spirit, you know, I've spoken tons like this and this happened, that happened. Wonderful. That was just the beginning. So we need to continually be filled in the Holy Spirit. And that is what we see in the lives of the apostles and believers, the Book of Acts. And I want to invite you to that, continually be filled, be filled. How is it possible to be filled, filled all the time? There are so many people and multiple fillings of the Holy Spirit. Won't Holy Spirit God be exhausted? No, we're talking about the infinite God, the Old Testament we read about him, the everlasting God. He's infinite, so infinity. And the Holy Spirit, I'm not sure if I gave you that analogy, but if you look at an ocean, when you take a drop, you can't dip with the ocean. Okay, all of us take drops, you just can't dip with the ocean. It's that big. So in the same way, we can keep receiving, keep receiving, be put the limit on God. So desire, desire, multiple infillings of the Holy Spirit and it will produce all of what we have seen and the Spirit of God, we can't box them up. There are so many other things that we can do in and through our lives as well, but just be open to the feelings of the Holy Spirit. Okay, let's move on. Verse 32, it's talking about the community of believers. What a beautiful community that in a troubled time, they could support one another, they could pray with one another. Beautiful, isn't it? Also, I don't want us to get stuck in the acts community. It's always, you take the good, leave the bad. Okay, so is this a loving fellowship? Is this a beautiful fellowship? Is it a fellowship that, you know, reveals God to the world? Very true, but you see, there are people at the end of the day, there is flaw in every community. So we will begin to see and talk about the flaws which this early church community also had. But at this point, what is being described as all positive, it's all great. So thank God for that verse 32. Now, the multitude of those who believe that of one heart and one soul, neither did anyone say that any of the things he possessed was his own. But they had all things in common, right? So going back to acts two, we've already talked about the context, we've already talked about the fact that it's a growing church, you know, growing set of leaders, they're making decisions for the church, they're establishing the organization, they are, you know, planning the resources, the finances, all that is happening. It's a growing church just to birth recently. So that is the reason why all the sharing was necessary. So what have we told you, anyone, neither did anyone say that any of the things he possessed was his own, but they, they had all things in common. Okay, so what does it show? Very selfless. Okay, very selfless. They were caring about each other. Verse 32. They were caring, they were united verse 33. And with great power, the apostles gave witness to the resurrection of the Lord Jesus, and great grace was upon them all. Okay. Features, features of the church unity, sacrificial love, you may call it third one, supernatural. Supernatural to the extent, right, that they're able to give witness for Christ. So if we can imagine a local church in a city or in a particular place, we would look at them and say, Oh, these people are also so loving, you know, they love one another, we can observe that they're united. And you could also say that there's something supernatural going on there. Whatever they do, you can see the power of God. For such was their witness, great grace was upon them. And here I told us the leadership is evolving. So currently, the apostles are the, you know, in the center. So the apostles, the great power, the apostles gave witness to the resurrection of the Lord Jesus. Maybe they had more opportunities than the others, but they were able to demonstrate the supernatural. Okay. That was 34. Nor was there anyone among them who lacked for all who were possessors of lands or houses sold them and brought the proceeds of the things that were sold. Okay. So again, that selfless way of giving is continuing. People are even selling what they have and giving to those who don't have. So you see there that nobody is lacking. Okay, nobody is lacking. In Psalm 132, what promises, he says, my house, Zion, the church is called as Zion there. That provision will be in Zion. And at this time, you can see the fulfillment of that. Nobody lacked anything, look, right? So there was provision for all the believers. And let's remember it was all voluntary. You don't really see that, you know, the apostles are telling people, you have to do like this, you have to sell the things. No, it was all voluntary. And I think Sister Rupa pointed it out also in our earlier class. So it was voluntary. And verse 35, so they sold all the things. And what are they doing? Laid them at the apostles feet and they distributed to each one as anyone had need. So voluntarily, they are bringing the resources to the apostles. So there is a system. Okay, somehow it seems like that, that they would give the resources to the apostles. The leadership would make decisions on how, where, when these resources need to be sent. So, but at the end of the day, nobody is lacking anything. That's 36. We have the introduction of notable personality, who will later on become quite popular in the Book of Fats. So, Joseph, who was also named Barnabas by the apostles. So what is the meaning of his name? Barnabas means son of encouragement. A Levite of the country of Cyprus, having land, sold it and brought the money and laid it at the apostles feet. So we are told about this good man who was a Levite. So he comes from a good land as well. He's wealthy. So again, think about the nature of the church of Jerusalem. There are poor people and also very rich people. Okay, so some have enough and they are able to sell it and give to the others. They are poor but they are receiving. So there's humility on both sides. You need humility to give, you need humility to even receive. So it's a very humble church. They are caring for each other. So in this manner, possessions are being supplied and it's a voluntary act where people are not being forced joyfully. They are making this decision. So let me just pause here. We completed Acts chapter 4. We can come back and pick up from Acts chapter 5. At this point, if there are things that you wanted to ask, you could please do that or just share your thoughts, anything that touched you, anything you found interesting in our discussion so far. So it could only mean two things. Something that you grasped which you're wondering about or you're completely blank, have nothing to wonder. Hi Pastor. Yes, hi Tisha. No, I am Claire. Thank you. It is very enlightening how the apostles that they thought about honor of a man, pretty much just paraphrasing in my word, men of integrity, set aside to look about the widows, to care about dealing about food but they did not stop per it was essential. But at the same time, they were not distracted by the needs and the needs of the people were the same. And when you look at it today, how people sometimes become so selfish. Oh, it's my, my, my. It's all about me, my money, my this. And they don't remember that. It's the Almighty God that gives you the power to get wealth as he says in church of anime. And you forget. He gives you the wisdom, knowledge, and the strength to work it. But yet still you cannot share with somebody. I was sharing with somebody and it brought me to, to this scripture came back to me acts and it's not the first I've done the studies on it. But it came back to me and always stood out like a sore thumb so to speak. That the person said to me, it's not my fault people are poor. I don't see why I should give them my money. And it really struck me. I'm like, wow, why, why would you think that way? You know, people, they were the babes that are always bit of poor. And they, they is not that you're saying your should squander your money, but some, they generally need help. And to see the need that we should help wherever we can, in the book of acts, these are exemplary men, you know, doing this work and still in prayer, right? And taking care of the church and the widows and looking out for the little ones, so to speak, because whatsoever we do to the least, you know, Jesus, they're still following Jesus's plan. Jesus always look out. He always feeding people. He's always looking out. No matter how weary he is, you saw when gender Baptist died and he went in the boat to console himself, then look after he was moved by the multitude came, not just one person. The multitude came and he fed them just the same and prayed for them. He was moved, but he had come, the Bible said he had compassion on them. So it's the same compassion we should have on the God's people. So I like the book of acts and I like what is showing us so we can still, in essence, practice that today. Do not forego it, practice it. Just as a person is important, just like how you talk about the supernatural, it is important too, but don't forget, there are needs to do that needs to be met. That's my tip. Thank you. Thank you, Tasha. Thank you for sharing your thoughts. And yes, it is a giving community and very relevant to their times. Of course, I pointed out that Paul does talk about taking responsibility for yourself and managing your resources yourself, but that's, you know, in that context, but right now people, as you said, they need help and the community was compassionate enough and it's beautiful. So, oh, we've already had a lot of times say I saw your hand raised and it's, you know, 1050. So if you don't mind, we could take up your question in the next class. We'll just pray and close. So I want to request someone please to pray that God will continue to, you know, enlighten us through the book of Acts. Father, we thank you for the studies. We thank you that we're here to learn and apply. Father, whatever this mighty book to our lives when the exemplary beavers of the apostles that have gone before us, the foreigners of the faith. Father, thank you so much and the work that the Holy Spirit has done and is still doing, the wind that is blowing, but I pray the same wind and the fire of Pentecost to locate us. I pray Lord God for a mighty outpouring upon each and every one of our lives that we will be moved by compassion and not only for our own needs, but in needs of the people. Lord, for prayer, for Lord, for physical food, for encouragement, for spiritual enrichment and uplifting. We thank you for healing and for deliverance. Lord, we pray that miracles and signs and wonders will follow us like God follows their apostles. In the mighty name of Jesus continue to pour out an APC and the administrative Lord and pastor Nancy. Thank you Lord for doing the work Lord. Thank you so much for giving them up in prayer for this course and this semester in Jesus name. Amen. Amen. Amen. Thank you. Thank you Tisha. Thank you everyone. Always appreciate your patient listening. I mean I pray that it will make a difference and that God will impart his word into each of you. Okay, so God bless and we shall meet again next week. See you then. Bye for now. Alright Tisha. Bye. Bye. Thank you. Thank you.


Thank you. I, I wish to start by apologizing for not being there, but thanks for arranging this room webinar so allowing me to talk to you. So, since there was enough information about me during the introduction. I'll just gonna move on to the talk, and the talk will be mainly on for location in power systems. So before I start, I'd like to acknowledge the sponsors of this work. I mean, mainly it was jointly sponsored by Department of Energy and National Science Foundation. And we did the work on this for school we are see that we are part of current. And I'd like to acknowledge the contributions of students when you think and Arthur Morko. So with that, we move on to the outline so I, I'd like to even though probably you all know what the full location problem is I'd like to just briefly describe it. And, and then talk about the formulation of that's proposed solution. And then I'll talk a bit about the implementation of that solution and some of the issues, and then show some examples using typical power systems under faults. And then summarize the contributions and tight answers if you have any questions after that. So, so the fault location problem is is an age old problem. It's not a new problem and it's essentially was down to catching and locating short circuits occurring in power systems. And these short circuits occur due to unexpected, but most of the time natural causes like lightning striking a line or a tree branch falling on a conductor. Or sometimes vegetation growing and reaching out to the to the height of the overhead lines and touching them, things like that so they cannot be always avoided. And when they happen, they trip the circuit breakers and take out the entire transmission lines out of service. And as a result, you know, they need to be dealt with located and repaired and so forth. So the problem is some of these lines are as I'm showing here in this diagram it's essentially the power system. Systems can be thought of as a graph where the nodes are the substations and and the branches are either the transmission lines or the transformers. And some of these lines may be really long in the order of hundreds of kilometers. So therefore if there's a fault, and even if the fault is cleared by the relays. It's important to know the exact location of the fault so that the crew can can go and attend the fault and the terrain may be rough, especially in rough weather in the middle of snowstorms and this and that. And so, so it's important to locate the fault as close as possible. So, so it's actually a two step process. The first thing is to identify the line which is faulted. And then once we know that then we would like to also know exactly where the fault is along that line. So we need to know the distance from one of the terminals of the line to the fault point. So I'm showing on this diagram or circles with the letter P, and they represent phasor measurement units. You are probably familiar with this but just to clarify phasor measurement units are these devices. Sample use high frequency sampling a sample voltages or currents. And, and they time stamp these samples using GPS. No matter where they are, they are synchronized with respect to each other to the GPS system and using these samples, they do a FFT and produce a phasor representing the voltage at that point where the measurement is taken. And they provide these phasor measurements, quite high rate, typically anywhere from 30 to 60 times a second. So they can provide these phases quite accurately and in a synchronized fashion. So, so the systems power systems are equipped with these PMUs. But not necessarily at all the buses at all the substations as shown here they may be located at a certain percentage of the substations in the system. Okay, so, so again the motivation even though I went through this, obviously public safety is one, we need to locate the fault fast, and also we wish to minimize the service interruption, because anytime you have a fault. And some of the customers may suffer because of that. And also, there is a cost associated with the reduced transmission capacity, and sometimes associated with that reduced security margin. This is related to the stability of the system either voltage or the angle stability, maybe reduce the margin for that. So, as I said this is a very old problem. It has been studied in the past. And by many people, and the solutions offered can be sort of categorized under three categories. Obviously, I mean you can probably group them in different ways but this is one way. You can look at it. One is those techniques which use the power frequency in other words you filter out the higher frequencies and you try to capture the 60 hertz signals. And there, you're having the voltage and the current captured, you try to find the effective impedance, looking into the line and there's a fault this impedance certainly becomes much smaller. And based on that, you try to estimate the location of the fault. There's also this category of methods which rely on traveling ways because anytime there's a fault, the fault generates or initiates a traveling way, a signal travels both ways. And if you have a way of capturing the wave front of this traveling way, and since these are synchronized sensors capturing it, you can capture the arrival times in a synchronized fashion. And based on that, you can triangulate and try to determine the location of the fault. This requires high frequency sampling because you need to capture this very fast traveling wave, which means that you probably cannot use the conventional instrument transformers like the current transformers and power transformers, including cut-offs around, you know, 5000, 5 kilohertz range. So you probably need to use one of those, you know, optical instrument transformers, optical CTs or PPs. So that is some additional complication here for implementing these methods. And then there's the whole group of methods which rely on AI and machine learning and so forth. And they try to use either, you know, the history, the recorded history or simulated fault scenarios to train. And then hopefully get a successful prediction when they actually measure the voltage and the current during the fault. So the method or the approach I will be talking about is probably can be classified as in the first category, but with a different sort of tilt in the sense that we are assuming that the system is not observable. In other words, we don't have enough PMUs or measuring instruments or sensors that will allow us to capture what's happening at the terminals of the fault of the line by these PMUs. So, so we assume that the phaser measurement units are installed only at a very small percentage of the system buses which represent the substations. And we also assume that we know the network topology and line models and so forth pre-fault before the fault occurred. So under this assumption, the question is can, can a fault on any line be located, and its fault type can be identified because we are also interested in identifying what kind of fault it was, whether it was three phase to ground fault or phase to phase fault, a phase to phase to ground fault, single phase to ground fault and so forth. So, so this is the question we wish to answer. So, so we start out to formulate this problem we start out by looking at the pre-fault network. Let's just write the network equations, admittance matrix times the bus voltages equating to the net injected currents. And here I'm showing just any, any branch in the line connecting buses K and M. And the corresponding rows columns in admittance matrix are highlighted there, and the pre-fault voltage multiplied by that and gives you the pre-fault net injected current vector. So, so then if we consider, if you consider a fault along that line KM line at the point F, which is an unknown point obviously, and consider a fault current and unknown fault current IF. That can be sort of incorporated into the network equations by augmenting the equations by one row column adding this fictitious bus F where this unknown fault is occurring. And we have this equation, and here we are also doing a difference equation instead of just writing the equation after the fault, we are writing the equation in such a way that we subtract the post fault network equations from the pre-fault network equations. So as a result, if you look at the equation here, you will see that we are calling this vector now delta V indicating that this is the difference between the post fault values minus the pre-fault values at each of those buses. And assuming that this fault occurs all of a sudden, so we approximate the changes in the net injected currents at every bus with zero because typically loads and generation, they don't really change that fast. In the instantaneous, the only change we expect of course is this fault current, which is the reason why the system is changed. So, given this equation, we can apply a reduction, a chron reduction, and get this equation. The interesting thing is, when we do that, we get our original admittance matrix back without any changes, and then of course here we have the changed values, the difference values in the bus voltages. And on the right hand side, because of the sparse connections of this fictitious point F to K and M, we will only see changes brought to entries in rho K and rho M in the current injection vector. So as a result, we have this picture where the right hand side current vector is empty completely other than those two entries corresponding to the terminals of the faulted branch. And then the voltage solution is essentially the changes at each and every bus voltage in the system. So, at this point, you can also think about it like this, we have the actual system with the faulted line, the fault current injection somewhere along the line, unknown point along the line. And the voltages have changed as a result of this fault by delta D, delta VK, delta M amount at each end, as well as everywhere else in the system. And then we can replace this picture by a picture where there is no fault so the line is not faulted, but we have these fictitious equivalent injected currents representing exactly the same operating condition created by the fault. So these two are equivalent and we tend to now use the bottom equivalent picture for the reasons we will see. So, so not only that we get this nice equation where y bus remains the same and there are only two non zeros on the right hand side vector. But also, these values, even though we don't know them, these are unknown values, but if we, we know what these values are that that those values can actually be used to determine the distance from the two terminals from terminal M and from terminal K. You can actually calculate the percentage length to the fault by using these two expressions and these are straightforward to derive from the prong reduction process. So if we knew these virtual or sort of equivalent injected currents, then we could have easily found the location of the fault using these expressions. So, so then the question is, how does it work? Does it really work before we try to formulate a solution? I'd like to show you an example just to show you how this thing works. So this is a very simple, small example, but it's interesting because this is a distribution system model and it contains not only three phase branches, but it also contains two phase, single phase branches. So it's a mixed three phase system having some branches, three phase, some branches, two phase, some branches, single phase. And similarly, the laws may be single phase, three phase or two phase. So it's a mixed system of lines in a distribution system. In this system, we simulate a fault along this branch or line section connecting bus two to bus five, and we do it in such a way that the fault occurs exactly one fourth of the line length from bus two. So, so by doing that, and if you simulate the fault, and we actually, we actually check how these virtual or equivalent injections looks like. And in this case, by the way, the fault is a phase to phase phase a phase B to ground fault. So this is the type of fault we are simulating along this line. So for this case, if you look at the results, you will see that we see all zeros as estimated as the entries in the current vector, except for the two ends, and the two ends only the two phases are significant. Because those are the phases which are folded like phase C doesn't show up as a virtual injection. And not only that if you look at the ratio here you see that it's one to three indicating that one part is three and the other part is one, which is exactly how we actually calculate based on these injections, the location of the fault the percentage starting from one end, going to the other. So this is just an example to illustrate or to verify this formulation. And now, if, obviously, this is a very simple approach, if we had a chance to measure the pre fault and the post fault voltages at all buses, that means if we have access to delta V. And it would have been a trivial process, we could have just measured these multiplied by the matrix, and that would have given us the two non zero entries in delta I, and from there we could just move forward and located the fault. However, unfortunately, we don't have PMUs at every bus, or we don't have enough PMUs to make the system fully observable so that we have access to those values in the voltage vector delta V. So, so what we can do is we can take the inverse of the admittance matrix, which we call Z, Z bus here, and rewrite this equation in the reverse order, and then assume that only a portion of the voltage buses are have PMUs, so we only have access to a small percentage of these voltage differences, measurements, and the rest of them we don't know. So that will partition the equation like this, and, and then we can look at it, essentially like this we are carving out a portion of Z bus, based on the available set of voltage measurements, and we are having this equation, which is a sort of rectangular coefficient matrix times delta I equals delta Dr, which is a, which is a, an undetermined set of equations. So that that that gives us this picture. In this picture, obviously, we are stuck, and we need to figure out a way to solve this equation. And the nice thing is that even though this is an undetermined set of equation, we already know that the solution is a sparse vector, there are only a few non zeros in it.  So we exploit that. And obviously, this is an old problems, nothing new, and it has been looked at earlier. So for this kind of undetermined set of equations, where you have a smaller number of equations than the number of unknowns. But you know that the unknown vector contains only few non zeros, even though you don't know where they are, which ones are those you know that there are a few. So, so this kind of sparse problems are dealt with earlier. And interestingly, of course, the group who dealt with it and came up with this nice solution is actually from there from your institution and statistics. I'm Shirani and his co workers, they have worked on this problem and produced some nice tools to use for these types of problems. And one of them is based on this last so the known as the least absolute thing which and selection operator, and using that optimization solvents optimization problem. They can actually find a solution to this under determined but sparse set of equations. So, so in our case, the sparse set of equations are given like this, unfortunately, this is a complex phaser equation. These are complex matrix, these are phasers these are complex numbers so we split them and turn the equation to a much larger dimension but real problem like this, the real and imaginary parts of the currents and so forth. It's a simple conversion and then apply the last so approach and and solve it this way. So, so it seems like this is a nice solution, and that will give us some usable results. There are a few caveats. So, one of them is that, as you know, I mean the systems power systems are protected by fast relaying action that are released, and they respond to fault currents, and based on the setting of these they can, you know, clear the fault, depending on how fast they operate it can take one or two cycles or more, but they don't certainly allow the fault to remain and to reach the post fault steady state value. And this is precisely what we are using because we need the post fault steady state value in order to use those pre fault and post fault steady state difference equations. So therefore, we wanted to make sure that we actually have access to those values and turns out that if you capture the voltage transients. And you can, because the PM use internally they have access to high frequency sampling of signals. So if you have access to those voltage transients during the initial few cycles, they can be used to predict the post fault state voltage phases. And one way and probably not the only way but the one way to do that is using chronic analysis. So here, throwing an example of that so this is the fault duration and then here default is cleared. So it doesn't allow this to continue and settle in a post fault steady state, which would have been like this if you allowed it to settle. And this is precisely what we want to use in the formulation so therefore what we need is to be able to use this window here when the fault is still on and there's a transient going on use that transient data to capture it, and to use that with some manipulation using the pro analysis and estimate the state long term steady state behavior of the signal. And indeed, you can do it. And here I'm showing one example of that here there's the fault. And the fault is cleared right there. And from then on, if you use the front analysis and do the prediction. The yellow signal is 100 times magnified version of the prediction error, and the blue and the red lines show the estimated and the measured signals, which are fairly, fairly close. And then of course you can predict in the end the steady state post fault steady state value based on this prediction. So that's, that's one issue that to be resolved. And based on that, we have looked at an example here this is a an example system with 118 sort of substations models and the three phase system for each and every one of these are three phase lines, the loads are three phase and so forth. And did test several different scenarios here. For instance, in this scenario we are looking at the three phase to ground fault occurring at 20% of the line. This line connecting bus 50 and 57 and looking at the currents, estimated by last hope, you notice that they are not strictly zero, there are certainly large ones that appear here. And those actually correspond to indeed bus 50 and bus 57 phases ABC, as shown here, but in order to sort of filter them out, we are using a threshold as you can see we put a threshold here, and we sort of throw out anything below the threshold, and just consider the ones about to find these virtual currents. And based on those and based on the expressions I showed earlier, using the ratios, we can actually estimate the publication fairly closely you know it's supposed to be 20% and 80% and the numbers we get for different phases for this case. You can also do a different kind of fault where there's fault between two phases face to face fault, and it's happening at 5% of the line length of line 101 to 102. Here as you can see since this is a face to face fault the number of non zeros we expect in the current vector are smaller. In this case, only two on each end 101 and 102. Again, we are using the threshold here. And, and we get the results which are again approximate but close this is 4.8 instead of five. This is 3.9 instead of five and this is 95 20 instead of 95 and this is 96 10 instead of 95%. Now, we were thinking about how to improve this a bit further. And then we said okay, we are identifying the faulted line based on this last algorithm. Why put all the burden on last so why not, you know, help it to further improve the accuracy of destination. Essentially what we do is once we look at once we lock in on the faulted line, then we know that those are the faulted line corresponding columns in Z are so you can pull those and create an ordinary problem in this case because now we have every no which line is the faulted line. So using this kind of approach by just, you know, pulling the columns corresponding to the identified line. We can indeed, if you look at this case for instance, the ones that we looked at earlier. In this case, we ran into some non zeros which are not supposed to be there by using lasso, even though the rest were correct. And then doing the oil less, we can clean it out and then get these results as shown here. And, and then and then similarly, we can do it for another case shown here between 50 and 57. Again, there was an incorrect value appearing here, and we were able to clean it up by using the oil less approach here. So, I guess with that, I would like to conclude this is a way to locate faults. If you have a limited number of synchronized voltage phasor measurements in a given power grid. You can improve this by using some sort of a prediction algorithm, based on something like pro need to take the transient sample recordings and determining the possible steady state values that way, because those are not going to be captured in use since the relays are not going to allow you to keep the fault that long and active and live in the system. Now finally, once the faulted branches identified, you can further improve on the accuracy of the estimation by doing one last, you know, these squares estimation, and that will provide you with better estimates for the fault location. The main advantage of this, of course, will disappear as we have as we install more and more numbers of PM use in the system. So, this is sort of an intermediate solution until that happens. On the other hand, if this works quite well. And you might save on investing on extra PM use if you can do the job with fewer PM use, instead of installing a PM at every bus, then maybe it might be a good solution to save some money some funds. Investing in PM use. I have included some publications at the bottom here, which are related to the presentation to present it work. And then I have my URL here in case you need to contact me for any further questions other than those you already have now. So I'm ready to answer any questions if you have it. Thank you. Okay, shall I go ahead and start answering the questions from the chat. Yes. Yes, so there is a question let me repeat the question. How well does this method work on identifying and locating high impedance faults. Yeah, so high impedance faults probably will not be handled by this because of of their. I mean, the way they they present themselves. They contain a lot of jitter a lot of high frequency signals and typically those faults. Since they don't produce sufficiently high currents. They may go under the radar in this, in this particular approach because the approach sort of relies on on the fact that the current is significant and and so are the equivalent currents that that we use to represent it. So more than likely it will not be able to catch high impedance faults. Okay, so there's another question to ask related to the distribution system. So transmission is easy with the amount of data available have you smart meter voltage event measurements used. I think we haven't we this this these are the results that I'm showing are all simulated results using the systems that we use. We have not used an actual distribution system for this purpose but we have used the. The distribution subcommittee system that there are a number of systems that I can be distribution subcommittee put together as typical distribution systems. One has 123 buses three phase. We use those systems to test this, but not using actual fault data. So, yeah, so there's another question about how you choose the threshold for less of fault current results. And that was just by trial and error by looking at, of course, since we are simulating results we know which, which equivalent currents are supposed to be there, and comparing those values for the equivalent currents and the other parents, we came up with an appropriate threshold for a given system. And turns out that once for a given system you set this threshold for different faults for different scenarios that threshold pretty much holds true, as long as you are using the same system. So that may be system dependent configuration topology dependent, but that was mainly the reason why we wanted to find an improvement. And that's the reason why we went to that OLS augmentation, because this threshold may be a bit sort of subjective, this choice of that threshold. I don't see any others. I have one question. Yes. Yeah. In the event of a cycle. Someone tries to manipulate a new. How can I distinguish it is a cycle or a fourth. Yes. Well, yeah, I think I don't know actually we haven't looked at that, but the thing is, unless the cyber attack is sort of persistent, because it should coincide with the fault otherwise. This is there's no way to find to determine the fault ahead of time, the full time. This should be a persistent attack to the, to the PMU. And maybe there is a way to identify persistent attacks in general. But no, we haven't looked at what will happen in that case. The other question I have is, if you know the three parts of our gene. What was the minimum number of PMU data or where should they be placed. Is there a placement problem? Because you are trying to, you're trying to identify reports with minimal number of new mission. So, yeah, I guess this is the PMU placement problem.  Some of the last few papers showing how to choose the right locations for these sensors, so that, for instance, you make each and every branch identifiable, because this impedance bus matrix is actually notoriously conditioned. And, and, in fact, I'm not showing all the details but we are actually using a QR decomposition. So we're not directly using Z bus but we are using a QR decomposition. So, so there are some, some tools, mathematical tools to determine the locations where you should have those sensors, those PMUs, in order for you to be able to identify faults on each and every branch in the system. So, we have done some of it in the first students going new fans pieces that are some examples of that, showing how you can choose locations for PMUs so that you do have that guarantee, but unfortunately in the power systems area. This is very much topology dependent so it's there is no generic way to say like on only need a certain percentage of buses to be covered in order for this to happen for each system it turns out to be a different number, different location. Any more questions.