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  • [♪INTRO]

  • Let's be honest: No one really enjoys airport security.

  • It's annoying, it can take forever,

  • and it seems like the rules are always changing.

  • People tell pollsters that they'd fly more if security wasn't such a hassle,

  • but most people also say they're fine sacrificing some privacy for more security.

  • But those screening areas where no one knows what to do with their shoes

  • are only one small part of it all.

  • Every airport is an onion of security measures that all work together,

  • and those layers are constantly shifting and evolving.

  • Over the last 10 years or so, at least in the United States,

  • some of that evolution has been inspired by game theorists.

  • These researchers have been helping decide where security should be,

  • how much there should be, and how often it should change.

  • And one common response to all those questions has been: be random.

  • Game theory is a broad subject that sits in between math and economics.

  • It originally focused on how people play games, like the name suggests.

  • So a game theorist might work out when to bluff in poker,

  • or why your friend Camille always hoards sheep in Catan.

  • But while some researchers still do study actual games,

  • the field has expanded far beyond those early roots.

  • Plenty of today's game theorists are looking at other situations

  • where intelligent actors (like groups of people)

  • interact with each other and make decisions.

  • So things like soldiers making choices on the battlefield,

  • businesses competing against each other, or even election results.

  • Or Braess's Paradox from our video about reducing traffic.

  • That's straight out of game theory.

  • Adding more roads can make traffic worse, not better.

  • Because we all try to make our own trip faster,

  • which ends up making everyone's drive slower, including our own.

  • Governments and businesses also bring in game theorists

  • to help with crucial decisions or to build new systems.

  • Like, imagine that you run an international airport in a large city,

  • and you've stopped a few people

  • who were planning to attack the airport in the past.

  • So you want police watching for anything suspicious,

  • you want dogs sniffing for anything suspicious,

  • and you want security checking people's belongings

  • for anything suspicious.

  • But you only have a certain amount of money,

  • a certain number of officers and dogs,

  • and you don't want everyone to completely hate your airport

  • because security takes five hours.

  • So what do you do?

  • You call a game theorist.

  • At least, that's what they did in LA back in 2007.

  • Now, to be totally clear, whether security screenings and the TSA

  • are the most effective way to find or stop threats

  • is a completely different question

  • from the one these researchers are trying to answer.

  • So the goal, both for these researchers and in this video,

  • isn't to dig into the science or sociology of security protocols in general.

  • We're just going to explain where game theory has been implemented

  • at airports so far, and what the reported results and criticisms have been.

  • And this all really started at LAX, the Los Angeles International Airport.

  • The Los Angeles World Airport Police

  • wanted checkpoints along the roads to LAX,

  • but there weren't enough police to cover every entrance every day.

  • So LAX contacted a professor named Milind Tambe

  • and asked what they should do.

  • Together, they developed a computer program called ARMOR,

  • short for Assistant for Randomized Monitoring Over Routes.

  • It generates recommended security schedules for the airport.

  • ARMOR is based on a kind of game theory called Stackelberg game theory.

  • In Stackelberg games, one person makes a move while the second watches,

  • and then the second has to respond to their move.

  • The model is usually applied

  • to businesses competing against each other to sell something.

  • One business goes first and charges what they want for, say, a T-shirt.

  • Then other businesses have to respond and choose what they want to charge

  • for their own cool, nerdy T-shirts

  • so that people still want to buy them,

  • but they're not so cheap that the business loses money.

  • But since the first business knows

  • that others are going to respond to their initial decision,

  • that changes what the first business does at the beginning.

  • So before anyone does anything,

  • you end up with a sort of

  • they know that we know that they know that we know…” kind of situation.

  • Tambe and other researchers have realized

  • that Stackelberg games can also apply to security situations.

  • The first player is the airport, setting up their security in a certain way.

  • The second player is someone trying to attack the airport

  • or even just bring something dangerous through security.

  • Each player gets to see what the other does

  • attackers can go to the airport and look at the security,

  • and security can monitor attackers whenever they catch something.

  • So based on the optimal strategy in certain kinds of Stackelberg games,

  • Tambe and the rest of the researchers who were asked for input

  • said that the solution to LAX's problem was more randomness.

  • If they couldn't cover every entrance with police every single day,

  • they also shouldn't have a regular schedule for which ones are guarded.

  • Like, if the airport had 6 entrances,

  • you shouldn't have police checkpoints at entrances 1, 2, and 3 on Day 1,

  • then 2, 3, and 4 on Day 2, then 3, 4, and 5 on Day 3.

  • Because it's not too hard to figure out

  • that on Day 107, entrances 5, 6, and 1 will be covered,

  • and entrances 2, 3, and 4 won't be.

  • The same goes for paths taken by police dogs patrolling the airport.

  • If they regularly followed the same route,

  • you could predict where they'd be at a certain time of day.

  • In these non-random cases, with the right information, someone could

  • sneak through an unguarded door or know they won't run into a dog.

  • Even if the schedules seem complex

  • to someone who's not paying close attention,

  • if they have a structure, they can probably be exploited.

  • A key element of ARMOR is also that

  • humans shouldn't try to put randomness into the schedule ourselves.

  • That's not enough.

  • Because no matter howLOL SO RANDOMwe think we are,

  • humans just aren't good at producing or identifying random sequences.

  • Our brains just like patterns too much.

  • One of the simplest examples is that

  • if researchers have people imagine a coin flip,

  • about 80% will sayheadscame up.

  • Because when we talk about coin flips, we usually sayheadsfirst.

  • Seriously.

  • So instead, Tambe and the other researchers designed ARMOR to produce

  • a mathematically random schedule, without a discernible pattern in it.

  • The program was also flexible enough to adjust based on new information

  • or pressing security concerns.

  • Like, if a certain entrance will be way busier than usual one day,

  • you'd probably want more security there than usual.

  • After six months of ARMOR,

  • the airport police were very positive about the program.

  • A few potential threats, like cars carrying weapons,

  • were arrested by officers scheduled by ARMOR.

  • The new random schedule also reportedly made police seem more present

  • at the airport,

  • and the program reduced the scheduling work of the people in charge

  • letting them do other work, instead.

  • ARMOR was successful enough at LAX that soon,

  • Tambe was one of a number of researchers hired by the TSA

  • to apply game theory to airports across the US.

  • There are hundreds of airports nationwide, and they're all different.

  • Each one has its own baggage area and ticket counters

  • and terminals and security desks

  • so you can't have the exact same security strategy at each one.

  • For one thing, that would be super expensive.

  • The TSA's budget might be large, but it's not that large.

  • Plus, it's just not necessary.

  • Some airports are more threatened than others.

  • That doesn't mean the whole budget should just be thrown at large airports

  • like LAX, either, though.

  • Because leaving the rest without security is a… bad idea.

  • The team's first step was a program called IRIS,

  • which stands for Intelligent Randomization In Scheduling.

  • It adapted the kinds of Stackelberg games used for ARMOR to schedule

  • where Federal Air Marshals,

  • a kind of in-flight security and police force,

  • should be flying.

  • Then, they developed GUARDS:

  • Game-theoretic Unpredictable and Randomly Deployed Security.

  • Clearly, they really like a good acronym.

  • With GUARDS, they didn't just look at handling one thing at a time,

  • like which roads to secure or which Air Marshals to put onto which flights.

  • GUARDS is focused on the upper layer of organization:

  • Where and how the TSA should monitor each airport

  • so that they're all as safe as possible, without any predictable patterns.

  • This means that GUARDS also had to take different security measures

  • and types of attackers into account.

  • Someone aiming for the ticket window likely has different goals

  • and strategies than someone targeting the planes.

  • Since these game theory-based approaches seem to have been effective

  • so far, we'll probably keep seeing more of them.

  • But that doesn't mean they're perfect, either.

  • GUARDS isn't designed to handle all the nuances of the real world,

  • and it can't dictate how every nook and cranny of every airport

  • in the country should be run.

  • It's still just a computer program running with a set of variables,

  • and can't include every possible threat in its scheduling calculations.

  • And to schedule well, each threat that it does handle has to be rated

  • like, essentially on a scale of 0-10.

  • Which obviously has its problems and subjectivity.

  • But in 2011, GUARDS was submitted to the TSA to be tested

  • at an undisclosed airport.

  • And if it was successful,

  • the TSA planned to incorporate the program into their scheduling elsewhere.

  • Although since then, they've been pretty quiet about what happened.

  • Which isunderstandable.

  • That's a security measure too.

  • Game-theoretic approaches to security also don't stop at the airport.

  • Tambe and other researchers have branched out

  • and developed a program called PROTECT,

  • or Port Resilience Operational/Tactical Enforcement to Combat Terrorism.

  • And it helps protect the port of Boston.

  • Ports are huge, open spaces; they're dealing with boats

  • and they're not contained in the same way that airports are.

  • Which means that the techniques that worked in an airport

  • might not work in a port, and PROTECT accounts for that.

  • According to the researchers, it uses a more accurate model than ARMOR

  • or GUARDS for how people make decisions, and it includes more information

  • about which points are more important to watch than others.

  • After recent incidents, researchers have also proposed ways

  • to use game theory to protect public spaces during events.

  • But that's an even harder problem!

  • You have another big space, but it's crowded with people

  • and there are a near-infinite number of things that could happen.

  • They've even proposed using game theory to address something

  • that might seem completely unrelated: protecting animals from poaching.

  • Illegal poaching, fishing, and logging are huge environmental problems,

  • but they keep happening because it's impossible to watch everything at once.

  • By treating poachers like opponents in certain kinds of games,

  • and looking at where they've gone so far,

  • game theorists can try and predict where they'll strike next.

  • Plus, poaching, fishing, and logging are all much more common

  • than any other type of attack we've talked about so far.

  • That's not a good thing, but it does mean that after game theorists

  • have made predictions, it's easier to check what actually happened.

  • That lets them see whether their models do a better job of protecting

  • lives than what we're doing now, and update them to do better in the future.

  • So whether it's airports or wildlife preserves,

  • game theorists are out there trying to make the world better for us

  • and all of our sheep-hoarding, Catan-playing friends.

  • Thanks for watching this episode of SciShow!

  • If you want to learn more about game theory

  • and the science of decision making,

  • we have a whole video explaining some of the basics.

  • And if you want to keep up with all sorts of deep dives into science topics,

  • you can click subscribe.

  • [♪OUTRO]

[♪INTRO]

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B1 中級 美國腔

美国机场如何改善安全(How U.S. Airports Might Revamp Security... Using Game Theory)

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    joey joey 發佈於 2021 年 07 月 02 日
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