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Real secure building... You're right, you must've been a PITA student.
Hehe.
There's a similar trick for getting into the penthouse suite (literally, inside the penthouse suite itself) at the Time hotel on W 49th in Manhattan. No lockpicking required. Discovered that one back in 2010 or thereabouts when I was really bored one evening. Sadly, this was before I had a smartphone, so no pics, only memories.
I think I understand how Joe learns these "tricks".
He wanders around and tries doors that are otherwise not protected. When they are open, he enters under the presumption that if the door is open and unprotected physically or verbally, that it must be publically accessible. Permission by plausible deniability.
I think I understand how Joe learns these "tricks".
He wanders around and tries doors that are otherwise not protected. When they are open, he enters under the presumption that if the door is open and unprotected physically or verbally, that it must be publically accessible. Permission by plausible deniability.
Step 1: Carry something that makes you look either official or important. If wearing a name badge on a loop turn it around.
Step 2: If confronted, just say "I'm sorry I thought this was the way to...."
Step 3: Revert to step 1 and walk away in the other direction.
I think I understand how Joe learns these "tricks".
He wanders around and tries doors that are otherwise not protected. When they are open, he enters under the presumption that if the door is open and unprotected physically or verbally, that it must be publically accessible. Permission by plausible deniability.
Pretty much. I do make a point to be observant for signs, and will generally not trespass in areas so marked. But there's a lot of neat stuff out there that's still accessible.
I've found some cool spaces beneath libraries, in the Atlanta and Chicago airports, *especially* in the Charlotte airport (there's a large conference room with comfy chairs and a very nice bathroom where you can chill if you've got some time to kill after normal business hours at CLT), lots of attics on University campuses, and so on.
The only places I've tended to shy away from are things like Grand Central, where the soldiers carry selective-fire rifles and it's public knowledge that there are certain rooms where their orders say to shoot first.
Step 1: Carry something that makes you look either official or important. If wearing a name badge on a loop turn it around.
Step 2: If confronted, just say "I'm sorry I thought this was the way to...."
Step 3: Revert to step 1 and walk away in the other direction.
That works well in places where they expect managers / foremen / engineers to be. I explored damn near every inch of the Meyer Werft shipyards in Papenburg, Germany just by wearing a blue hardhat and walking around with a sense of purpose while carrying a torch and a clipboard. Nobody wants to talk to people carrying clipboards.
At that yard, workers wear yellow hats, execs wear white. Blue is for engineers, and engineers are assumed to have a reason and authorization to be wherever they are.
Even boarded a ship being constructed in the next drydock over from ours for a rival line (Aida) and walked all over it. Nobody ever said a thing to me besides guten morgen.
But, to be honest, I'm always a little more nervous when pulling that kind of stunt than when spelunking. Closest I ever came to getting caught was about 15 years ago in Mason, OH. Decided to enter (during late evening, not quite night) the main building of the former Voice of America Bethany complex, which had been shut down a few years prior. Got inside and noticed that it had apparently been given over to administrative offices for various city / county agencies. But it still had a lot of the original stuff that gave it a groovy cold-war vibe, like the huge map of the world with little light bulbs that showed the operating status of all of the repeaters and transmitters around the globe, above the big mahogany table with the heavy glass ashtrays.
Then I noticed the red light on the motion sensor.
I hauled *** out of there, and had just turned back out onto the main road about a quarter-mile before when the police car went screaming by my in the other direction. He couldn't have possibly seen me turn out of the long dirt road leading up to the building.
I never did notice whether there was a security camera that got a good look at me. Major lapse of situational-awareness on my part, and I've become a lot more careful since then.
I was caught in and thrown out of an unsecured secure area of infield turn 1at the Daytona International Speedway during the Rolex 24 last month. Security guy walking by did a double take and wanted a closer look at my badge. If I go back again I'll try to mimic the guys emptying the trash cans if I can find an empty can and a hand truck. If you are wheeling around a garbage can and wearing a safety vest you can go anywhere.
Pretty much. I do make a point to be observant for signs, and will generally not trespass in areas so marked. But there's a lot of neat stuff out there that's still accessible.
I've found some cool spaces beneath libraries, in the Atlanta and Chicago airports, *especially* in the Charlotte airport (there's a large conference room with comfy chairs and a very nice bathroom where you can chill if you've got some time to kill after normal business hours at CLT), lots of attics on University campuses, and so on.
The only places I've tended to shy away from are things like Grand Central, where the soldiers carry selective-fire rifles and it's public knowledge that there are certain rooms where their orders say to shoot first.
We need an MT.net TV thread with regularly scheduled episodes of Joe Perez Everything, Monk's Beverage Review, Samnavy Shooty Stuff, and Braineack's Cats.
Following up on my earlier elevator rant, seriously, is this so hard?
Lift Traffic Analysis: Formulae for the General Case
R D Peters BSc
Ove Arup & Partners, 13 Fitzroy Street, London W1P 6BQ, UK
Received 11 August 1989
Telephone +44 (0)1494 717821
Fax +44 (0)1494 716647
Email richard.peters@peters-research.com
Summary
Lift or elevator passenger traffic analysis is generally based on an up peak calculation. Various authors have considered other specific passenger flows for down peak, two-way and interfloor traffic. This paper gives formulae for the general case. The formulae are based on a Poisson approximation of passenger arrivals at a lift landing station. The probable number of stops and probable reversal floors are calculated, allowing the round-trip time, waiting interval and capacity factor to be determined. The number of calculations is such that a computer is needed to implement the formulae, though the final result may be checked by hand.
List of Symbols
µi Passenger arrival rate at floor i (person s-1)
dij Probability of the destination floor of a call from i being the jth floor
T Waiting interval (s)
N Number of floors
Pij(n) Probability of n passengers travelling from the ith to the jth floor in the time interval T
Pij Probability of no calls from the ith to the jth floors in the time interval T
pS1 Probability that a lift will stop at the lowest floor
pUSs, pUS3,...pUSN-1 Probability that the lift will stop at each of the intermediate floors on its' journey up
pSN Probability that the lift will stop at the highest floor, N
pDSN-1,...pDS 2 Probability that the lift will stop at each of the intermediate floors on its' journey down
S Probable number of stops
pHn Probability of nth floor being the highest reversal floor
pLn Probability of nth floor being the lowest reversal floor
H Highest reversal floor
L Lowest reversal floor
JWI(i,j) Journey waiting interval for passengers travelling from the ith to the jth floor(s)
T(n) Waiting interval, zone n
SPLIT (Q, i, j) Proportion of passengers travelling from the ith to the jth floor who are using lifts in zone Q
1 Introduction
Traditional up peak lift design calculations, though simple and effective, are not always applicable to today’s buildings which may have underground car parks, restaurant floors, etc. Various authors have considered two-way(1), down peak and interfloor traffic. This paper deals with the ‘general case’.
The following calculations are based on the fundamental design criterion for a lift system, the round trip time. Formulae are given for the probable number of stops a lift car makes during a round trip and the average highest and lowest reversal floors. Section 6 demonstrates how passenger traffic is split between different groups of lifts which may be of a different size, speed, etc., or which may not serve all the same floors.
As the formulae are completely general, it is possible to analyse any practical configuration of lifts (double decker lifts have not been considered, though the theory could be extended to consider these).
2 Poisson approximation
It is generally accepted that the arrival of passengers at a lift landing station is reasonably approximated by a Poisson process. This gives us the result:
When calculating probabilities, it is generally easier to calculate the probability of something not happening and then subtract this from 1 to arrive at the probability of the event happening . So, let
Pij = Pij(0)
which is the probability of no calls from the ith to the jth floor in the time interval T. From),
Pij= exp(-µi Tdij)
3 Probable number of stops
When calculating the probable number of stops, it is necessary to consider both the up and down journey of the lift, as a lift may stop at a floor twice during a single round trip.
The probability of the lift stopping at a floor is one minus the probability that there are no calls to or from that floor. This gives us the results:
(∏ is a mathematical symbol meaning multiply all the terms over this range.)
The total number of stops S is calculated by adding together all the terms:
4 Reversal floors
4.1 Reason for calculation
In an ‘average’ journey a lift, in many situations, is unlikely to reach the lowest or highest floor of the building. To make a more accurate calculation of the round-trip time, it is necessary to calculate the average lowest and highest reversal floors, L and H.
4.2 Highest reversal floor
The probability of the jth floor being the highest reversal floor is the product of the probability that there is a call from a lower floor to j or from j to a lower floor with the probability that there are no calls to or from floors above j:
A good check for this is that:
Given the probability of each floor being the highest reversal floor, the average highest reversal floor, H is simply:
4.3 Lowest reversal floor
Similarly, we can calculate the probability of the jth floor being the lowest reversal floor, which is the product of the probability that there is a call from a higher floor to j or from j to a higher floor with the probability that there are no calls to or from floors below j:
(13)
5 Implementing the formulae
In a traditional up-peak analysis, a capacity factor of say 80% is assumed and the round trip time and five minute ratio are calculated accordingly. In the general analysis, all the formulae are dependent and solving is only practical using a computer to iterate until a solution is reached.
Note that for a general analysis the capacity factor must be calculated and not assumed, as passengers may join or leave a lift at any floor. The ‘average number’ of passengers in the lift car at each stage of the lift’s journey must be assessed and the capacity factor calculated for where the lift is most full.
For example, at the ith floor, going up, the number of passengers entering the car is:
and the number leaving the car is:
6 Overlapping Zones
6.1 Definition
Lifts which serve the same floors and are of the same size, speed, capacity, etc. may be defned as being in a zone. If different zones do not serve the same floors, we can treat each as being independent, carrying out the calculations already given for each zone separately. However if a passenger could use lifts in either of the two or more zones to make his/her journey, we have ‘overlapping zones’ and need to split up the passenger traffic between the zones before doing the calculations.
6.2 Journey waiting interval
To calculate the split of passengers between zones, consider first the journey waiting interval, which is defined for each possible journey. Consider a passenger travelling from the i th to the j th floor. In time t, a lift serving zone 1 arrives at floor i t/T(1) times.
If both floors are also served by zone 2, then a lift arrives at floor i from zones 1 or 2 t/T(1)+t/T(2) times.
So the journey waiting interval is given by
Taking the general case, we get:
(16)
where {Z} = {all zones serving both the ith and the jth floor}
6.3 Split of passengers between zones
In time t, a lift from zone Q arrives at i t/T(Q) times; therefore
6.4 Implementing the formulae
The calculation for split requires another iteration as split and waiting intervals depend on each other. Again, the only practical way to implement the formulae is by using a computer, though the results may be checked by hand.
References
Strakosch G R Vertical Transportation: Elevators and Escalators 2nd edn (New York: John Wiley & Sons) (1983)
Alexandris N A Mean highest reversal floor and expected number of stops in lift-stairs service systems of multi-level buildings Applied Mathematical Modelling 10 139-143 (April 1986)
Barney G C and dos Santos S M Elevator Traffic Analysis Design and Control 2nd edn (London: Peter Peregrinus) (1985)
1) Report is bogus as it is written in Queen's English, rather than American.
2) Authors are wonderful because they showed both original publication date and the posted date. This is sorely lacking in much of Interweb information
3) Shows that such algorithms have been considered, and even written. However, we do not know if they have ever been implemented (apparently not in your apartment building).
4) Is the reason for (3) above laziness on the part of designers, or truly a wear-and-tear fear?
02-14-2017, 12:09 PM
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cheers.
