OpenLLM-France/wikimedia huggingface dataset:
# Fundamentals of Transportation/Shockwaves/Additional Problems
## Additional Questions

* What example or explanation can be given for shockwaves on freeways?
* Explain the 4 phases of traffic diagram and why each has the slope it has.
* How do microscopic and macroscopic models of traffic flow differ?
* Why does flow decrease in phase 3 of the traffic phase diagram?
* What types of events can create rolling roadblocks?
* How is speed calculated from a flow v. density diagram?
* What is a shockwave and how do you compute its speed?
* Can service rate decrease with increasing congestion?
* What factors affect the wave speed?
* What does the slope of the shockwave represent in the graph?
* Is it possible to increase the density of the queue and still have the shockwave going downstream? What would be a an example of this?
* Why is the bottleneck QK curve projected on the mainroad QB curve to find the speed?
* What is Greenshields model, does it accurately predict traffic flow?
* What is the phase in traffic flow, after density is at its max, called?
* What happens to speed when the density increases?
* What does the slope represent in a traffic phase diagram
* Give an example of density rising and speed dropping
* What is $v_{w}$ ?
* What does it mean when the flow rate begins to decrease in the traffic phase diagram?
* During the bottleneck phase, what happens to flow as density increases? (flow remains constant)
* How can you tell if the queue grows with or against traffic?
* Does the bottleneck always slow traffic?
* How can traffic avoid the bottleneck?
* How do incidents and rolling roadblocks affect shockwaves differently?
* How do speed, density, and flow change during the peak hour
* List six examples where gaps are important.
# Fundamentals of Transportation/Shockwaves/Problem

Flow on a road is $q_{1}=1800veh/hr/lane$, and the density of $k_{1}=14.4veh/km/lane$. To reduce speeding on a section of highway, a police cruiser decides to implement a rolling roadblock, and to travel in the left lane at the speed limit ($v_{2}=88km/hr$) for 10 km. No one dares pass. After the police cruiser joins, the platoon density increases to 20 veh/km/lane and flow drops. How many vehicles (per lane) will be in the platoon when the police car leaves the highway?
How long will it take for the queue to dissipate?
# Fundamentals of Transportation/Sight Distance/Homework
## Homework

* Name five principal characteristics of visual reception important in driving.
* You are shown an accident scene with a vehicle and a tree on uphill grade of 3%. The vehicle was estimated to hit the tree at 120 km*h$^{−1}$ . The average length of skid marks was 20 meters. You have found that a car traveling that section under similar weather conditions at 60 km*h$^{−1}$ can stop in 60 m. What was its initial speed?
* Draw a road's cross-section and label the elements.
* How do the calculations of stopping sight distance and passing sight distance differ?
* What is the recommended value used for perception reaction time according to AASHTO?
* What is a standard lane width used in new highway designs (to nearest foot or centimeter)?
# Fundamentals of Transportation/Shockwaves/Solution

Flow on a road is $q_{1}=1800veh/hr/lane$, and the density of $k_{1}=14.4veh/km/lane$. To reduce speeding on a section of highway, a police cruiser decides to implement a rolling roadblock, and to travel in the left lane at the speed limit ($v_{2}=88km/hr$) for 10 km. No one dares pass. After the police cruiser joins, the platoon density increases to 20 veh/km/lane and flow drops. How many vehicles (per lane) will be in the platoon when the police car leaves the highway?
How long will it take for the queue to dissipate?
Step 0
Solve for Unknowns:
Original speed
$v_{1}={\frac {q_{1}}{k_{1}}}={\frac {1800}{14.4}}=125km/h\,\!$
Flow after police cruiser joins
$q_{2}=k_{2}v_{2}=88*20=1760veh/h\,\!$
Step 1
Calculate the wave velocity:
$v_{w}={\frac {q_{2}-q_{1}}{k_{2}-k_{1}}}={\frac {1760-1800}{20-14.4}}=-7.14km/hr\,\!$
Step 2
Determine the growth rate of the platoon (relative speed)
$v_{r2}=v_{2}-v_{w}=88-(-7.14)=95.1km/hr\,\!$
Step 3
Determine the time spent by the police cruiser on the highway
$t=d/v=10km/88km/hr=0.11hr=6.8minutes\,\!$
Step 4
Calculate the Length of platoon (not a standing queue)
$L=vt=95.1km/hr*0.11hr=10.46km\,\!$
Step 5
What is the rate at which the queue grows, in units of vehicles per hour?
$\Delta {q}=q_{1}-k_{1}v_{w}=q_{2}-k_{2}v_{w}=1800-(14.4*-7.14)=1760-(20*-7.14)=1902veh/hr\,\!$
Step 6
The number of vehicles in platoon
$L_{p}k_{2}=10.46km*20veh/km=209.2vehicles\,\!$
OR
$\Delta {q}t=1902veh/hr*0.11hr=209.2veh\,\!$
How long will it take for the queue to dissipate?
(a) Where does the shockwave go after the police cruiser leaves? Just reverse everything?
${{v}_{w}}={\frac {{{q}_{2}}-{{q}_{1}}}{{{k}_{2}}-{{k}_{1}}}}={\frac {1800-1760}{14.4-20}}=-7.14km/hr$
Second wave never catches first.
(b) Return speed to 125, keep density @ 20? $q_{2}=20*125=2500\,\!$
${{v}_{w}}={\frac {{{q}_{2}}-{{q}_{1}}}{{{k}_{2}}-{{k}_{1}}}}={\frac {2500-1760}{20-20}}=\infty km/hr$
Second wave instantaneously catches first
(c) Return speed to 125, keep density @ halfway between 14.4 and 20? $q_{2}=20*125=2500\,\!$
${{v}_{w}}={\frac {{{q}_{2}}-{{q}_{1}}}{{{k}_{2}}-{{k}_{1}}}}={\frac {2150-1760}{17.2-20}}=139km/hr$
Second wave quickly catches first
${\begin{aligned}&139*t=7.14*\left(.11+t\right)\\&\left(139-7.14\right)t=7.14*11\\&t=0.006h=.35\min =21\sec \\\end{aligned}}$
(d) Drop upstream q,k to slow down formation curve.
${{v}_{w}}={\frac {{{q}_{2}}-{{q}_{1}}}{{{k}_{2}}-{{k}_{1}}}}={\frac {1780-1760}{14.24-20}}=-3.47km/hr$
Second wave eventually catches first
(e) If $q_{upstream}$ falls below downstream capacity, wave dissipates
${{v}_{w}}={\frac {{{q}_{2}}-{{q}_{1}}}{{{k}_{2}}-{{k}_{1}}}}={\frac {1250-1760}{10-20}}=+51km/hr$
Forward moving wave.
# Fundamentals of Transportation/Sight Distance/Problem

You see a body lying across the road and need to stop. If your vehicle was initially traveling at 100 km/h and skids to a stop on a 2.5% upgrade, taking 75 m to do so, what was the coefficient of friction on this surface?
# History of Islam/Modern period/Azerbaijan
## Azerbaijan

Following the politics of glasnost, initiated by the last General Secretary of the Communist Party of the Soviet Union, Mikhail Gorbachev, civil unrest and ethnic strife grew in various regions of the Soviet Union, starting with Nagorno-Karabakh, a region of Azerbaijan SSR. The disturbances in Azerbaijan, in response to Moscow's indifference to already heated conflict, resulted in calls for independence and secession from USSR, which subsequently culminated in the events of Black January in Baku. At this time, Ayaz Mutallibov was appointed as the First Secretary of the Azerbaijan Communist Party.
Later in 1990, the Supreme Council of Azerbaijan SSR dropped the Soviet Socialist words from the title, adopted the Declaration of Sovereignty of Azerbaijan Republic, a constituent member of Soviet Union, and restored the modified flag of Azerbaijan Democratic Republic as a state flag. In early 1991, the Supreme Council of Azerbaijan established the institute of presidency, and Ayaz Mutallibov was elected as the first president by the Council. On September 8, 1991, Ayaz Mutallibov was elected as president in nationwide elections, in which he was the only running candidate.
On October 18, 1991, Supreme Council of Azerbaijan adopted a Declaration of Independence, which was affirmed by a nationwide referendum in December 1991, when Soviet Union was officially dissolved. The early years of independence were overshadowed by the Nagorno-Karabakh War with neighboring Armenia. By the end of hostilities in 1994, Azerbaijan lost control of up to 16% of its internationally recognized territory including Nagorno-Karabakh itself.[15][16] In 1993, democratically elected president Abulfaz Elchibey was overthrown by a military insurrection led by Colonel Suret Huseynov, which resulted in the rise to power of the former leader of Soviet Azerbaijan, Heydar Aliyev. In 1994, Suret Huseynov, by that time a prime minister, attempted another military coup against Heydar Aliyev, though failed, was arrested and charged with treason. In 1995, another coup attempt against Aliyev, by the commander of the military police, Rovshan Javadov, was averted resulting in the killing of the latter and disbanding of Azerbaijan's military police.
Although during his presidency, Aliyev managed to cut down the country's unemployment, reined in the criminal groups, established the fundamental institutions of independent statehood, and brought stability, peace and major foreign investment, the country was tainted by rampant corruption in the governing bureaucracy. In October 1998, Aliyev was reelected for a second term. Despite the much improved economy, particularly with the exploitations of Azeri-Chirag-Guneshli oil field and Shah Deniz gas field, Aliyev's presidency became unpopular due to vote fraud, wide-spread corruption and objection to his autocratic regime. The same harsh criticism followed the elections of former Prime Minister Ilham Aliyev, the second leader of New Azerbaijan Party after the death of his father Heydar.
# History of Islam/Modern period/Brunei
## Brunei

In 1959, a new constitution was written declaring Brunei a self-governing state, while its foreign affairs, security, and defence remained the responsibility of the United Kingdom, now represented by a High Commissioner. An attempt in 1962 to introduce a partially elected legislative body with limited powers was abandoned after the opposition political party, Parti Rakyat Brunei, launched an armed uprising, which the government put down with the help of British forces. In the late 1950s and early 1960s, the government also resisted pressures to join neighbouring Sabah and Sarawak in the newly formed Malaysia. The Sultan eventually decided that Brunei would remain a separate state.
In 1967, Omar Ali Saifuddin abdicated in favour of his eldest son, Hassanal Bolkiah, who became the 29th ruler. The former Sultan remained as Defence Minister and assumed the royal title Seri Begawan. In 1970, the national capital, Brunei Town, was renamed Bandar Seri Begawan in his honour. The Seri Begawan died in 1986.
On January 4, 1979, Brunei and the United Kingdom signed a new treaty of friendship and cooperation. On January 1, 1984, Brunei Darussalam became a fully independent state.
# History of Islam/Modern period

Many people in Islamic countries also see a broader and positive role for Islam in Politics . Political Islam is powerful in all Muslim-majority countries. Islamic parties in Turkey, Pakistan and Algeria have taken power at local, provincial and even Federal level.
* Afghanistan
* Albania
* Algeria
* Azerbaijan
* Bahrain
* Bangladesh
* Bosnia and Herzegovina
* Burkina Faso
* Brunei
* Chad
* Comoros
* Djibouti
* Eritrea
* Egypt
* The Gambia
* Guinea
* Indonesia
* Pakistan
* Saudi Arabia
* Nuclear capabilities
* Conflicts with Israel
* Recent history
* Political Fault Lines
# History of Islam/Modern period/Bangladesh
## Bangladesh

The borders of the region that constitutes present day Bangladesh were established in the 1947 Partition of India when the region became the eastern wing of newly formed Pakistan. The pairing, based on their common religion (Islam), proved geographically awkward since an expanse of foreign Indian territory, 1 600 km (1 000 mi) wide, separated the two wings. Subjected to political and linguistic discrimination as well as economic neglect at the hands of West Pakistan, the Bengalis of East Pakistan declared independence in 1971. After a civil war, with help from India and the USSR, Bangladesh was born. In spite of its liberation narrative, Bangladesh's development has since been marred by political turmoil, with fourteen different heads of government and at least four military coups.
Bangladesh is among the most densely populated countries in the world. The population is generally poor, rural and Muslim. Geographically the country straddles the fertile Ganges-Brahmaputra Delta and is subject to annual monsoon floods and cyclones. The government is a secular parliamentary democracy which has been suspended under emergency law since January 2007. Bangladesh is a member of the Commonwealth of Nations, SAARC, BIMSTEC, the OIC and the D-8.
# GCSE Computer Science/Internet principles of operation

* Specification link
* Show understanding of the role of the browser and Internet server - 2016 CIE Syllabus p11
* Specification link
* Show understanding of what is meant by hypertext transfer protocol (http and https) and HTML - 2016 CIE Syllabus p11
* Specification link
* Distinguish between HTML structure and presentation - 2016 CIE Syllabus p11
* Specification link
* Show understanding of the concepts of MAC address, Internet Protocol (IP) address, Uniform Resource Locator (URL) and cookies - 2016 CIE Syllabus p11
# GCSE Computer Science/Fundamentals of computer systems

* Specification link
* Develop a mental model of a computer system
* Define a computer system
* Describe the importance of computer systems in the modern world
* Explain the need for reliability in computer systems
* Explain the need for professional standards
* Consider ethical, environmental and legal considerations when creating computer systems
* OCR Specification

## What is a computer?

You have probably had a lot of experience with computers. They are a type of machine or device which can be programmed. Computers range from the desktop or laptop you are probably reading this on, to a computer in a vending machine or supermarket checkout. Computers are everywhere in out modern life, and are incredibly important to the functioning of the modern world.
* Extension
* The first programmable computer was designed in 1837 by Charles Babbage and Ada Lovelace.
All computer systems work in a similar way. They have inputs, processes and outputs. Take making a phone call on a mobile phone as an example.
| Input | Process | Header text |
| User uses touchscreen to enter the number in | Phone makes contact with towers, and is connected to the other phone | Speaker outputs voice of other person |

## Reliability of computer systems

Considering that computers are currently used for so much in the modern world, keeping them running well and constantly is an important consideration. A Crittical system is one which needs to constantly be running, or else there is a risk of death, serious injury, or financial problems.
* Examples
* Why does a life support system need to be reliable? [3]
* In a question like this, you should look at the number of marks, and try to make roughly that number of developed points.
* A life support system is a particular type of critical system. A critical system is one which would cause death, serious injury or financial loss if switched off. In the case of a life support system, failure can cause death of the patient. If a life support system was not reliable, it could cause death of a patient. For this reason it will need to be reliable.
Other examples of critical systems include utilities, banking, emergency communications and air traffic control.
# GCSE Computer Science/High- and low-level languages
## High and Low Level Computer Languages

* Specification link
* Show understanding of the need for both high-level and low-level languages - 2016 CIE Syllabus p13

## Computer Language Translators
### Compilers and High Level Languages

* Specification link
* Show understanding of the need for compilers when translating programs written in a high-level language - 2016 CIE Syllabus p13

### Interpreters and Machine Code

* Specification link
* Show understanding of the use of interpreters with high-level language programs - 2016 CIE Syllabus p13

### Assemblers and Assembly Languages

* Specification link
* Show understanding of the need for for assemblers when translating programs written in assembly language - 2016 CIE Syllabus p13
Lain wants to build a computer game. She decides on using an assembly language as it would offer the best performance. Give an explanation as to why she should consider using a higher level language [2]
Answer:
High level languages are easier to code than low level languages (1 mark) They are closer to English and the same output can be achieved in fewer lines of code (1 mark)
Accept any valid explanations on the advantages of high level languages relating to the context(processor specific, performance inst needed, complex problem)
# GCSE Computer Science/Logic gates

Logic gates are the basic building blocks of any digital system. It is a circuit having one or more than one input and only one output. There are four main types of gate; NOT, AND, OR and XOR. There are also three gates which are the inverse of one of the main gates; NAND, NOR and XNOR. These inverse gates are the equivalent of the main gate type followed by a NOT.

## Truth Tables

* Specification link
* - Draw truth tables and recognise a logic gate from its truth table - Produce truth tables for given logic circuits - 2016 CIE Syllabus p12
A truth table shows all of the possible inputs and outputs for a logic circuit. The example below is for a NOT gate. It shows that if the input is a 1 then the output is a 0 and vice-versa.
| IN | OUT |
| 0 | 1 |
| 1 | 0 |

## Gate Types

* Specification link
* - Understand and define the functions of NOT, AND, OR, NAND, NOR and XOR (EOR) gates, including the binary output produced from all the possible binary inputs - Recognise and use ... standard symbols used to represent logic gates - 2016 CIE Syllabus p12

### NOT

A NOT gate will invert, or flip, any input. If the input is a 1 then it will output a 0 and vice-versa.
| A | Y |
| 0 | 1 |
| 1 | 0 |

### AND

An AND gate will return a 1 if, and only if, both of the inputs were a 1. If either, or both, inputs are a 0 then the output will also be 0.
| A | B | Y |
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |

### OR

An OR gate will return a 1 if either, or both, of the inputs are a 1. It will only return a 0 if both inputs were a 0.
| A | B | Y |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |

### XOR

The XOR gate will return a 1 if either, but not both, of the inputs are a 1. If both, or neither, input is a 1 then it will return 0.
| A | B | Y |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |

### NAND

The NAND gate is the opposite of an AND gate.
| A | B | Y |
| 0 | 0 | 1 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |

### NOR

The NOR gate is the same as an OR followed by a NOT, so is the inverse of an OR gate.
| A | B | Y |
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 0 |

### XNOR

The XNOR gate is the same as an XOR followed by a NOT, so is the inverse of an XOR gate.
| A | B | Y |
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |

## Logic Circuits

* Specification link
* - use logic gates to create electronic circuits - produce a logic circuit to solve a given problem or to implement a given written logic statement - 2016 CIE Syllabus p12
A logic circuit is an electronic circuit which includes one or more logic gates. Below is an example of a logic circuit together with its logic table:
| A | B | A AND B | A OR B | Q |
| 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 1 | 0 |
| 1 | 0 | 0 | 1 | 0 |
| 1 | 1 | 1 | 1 | 1 |
# Futurebasic/Language/Reference/log10
## Log10
### Syntax

commonLog# = LOG10(expr)

### Description

Returns the common logarithm of expr. the common logarithm uses "10" as its base. LOG10 always returns a double-precision result.

### See Also

LOG2
# Futurebasic/Language/Reference/machlg
## Syntax:

MACHLG {constant|variable}[,{constant|variable}...]

### Description

Instructions the compiler to insert MC680x0 machine language instructions into the compiled code at the current location; these instructions are executed when the program is run.
Each constant is treated as a 2-byte instruction, and is inserted directly into the code stream. Typically, you will express a constant as a 4-digit hexadecimal number. Each variable is translated into an instruction which loads the variable's address into register A0.
The MACHLG statement is valid only for a "cpu68K" compile, and you should use only MC680x0 machine language instructions in the argument list (not PPC instructions). FB generates an error if you attempt to use MACHLG in a program compiled with the "cpuPPC" or "cpuFAT" options. To get around this problem, you can put the MACHLG statement inside a "COMPILE LONG IF cpu68K" block; in that case, the MACHLG instruction will be ignored in a PPC compile.
Note: It's recommended that you use FutureBasic's "Inline Assembler" syntax rather than the MACHLG statement when you need to insert machine language instructions. Not only does this make your code easier to read, but it also allows you to insert PPC instructions as well as MC680x0 instructions.
See Also:
BEGINASSEM...ENDASSEM
# Futurebasic/Language/Reference/locate
## LOCATE
### Syntax

LOCATE h,v

### Description

This statement moves the pen position in the current output window to text column h and text row v, based on the current font family and font size. The pen's horizontal placement is based on an "average" character width; you can't count on this position to encompass exactly h characters unless you are using a mono-spaced font. LOCATE 0,0 places the pen at the upper-leftmost character position in the window.

### See Also

CSRLIN; POS
# Futurebasic/Language/Reference/lof
## LOF
### Syntax

numRecords = LOF(deviceID [,recordLength])

### Description

If deviceID is the ID number of an open file, LOF returns the total number of records in the file. If deviceID equals _modemPort or _printerPort (and the specified device is open), LOF returns the total number of records currently in the device's input buffer. If there is a "partial" record at the end of the file (or input buffer), it is included in the count.
The returned record count is based on the record length given in recordLength, if it's specified. If this parameter is omitted, LOF uses the record length that was specified in the OPEN statement when the file or the port was opened. If recordLength is omitted and no record length was specified in the OPEN statement, a default record length of 256 is used.
To determine the total number of bytes in the file or in the serial input buffer, use LOF(deviceID,1).

### See Also

RECORD; REC; LOC; OPEN
# Futurebasic/Language/Reference/log2
## LOG2
### Syntax

base2Log# = LOG2(expr)

### Description

Returns the base-2 logarithm of expr. LOG2 always returns a double-precision result.

### See Also

LOG10
# Futurebasic/Language/Reference/long fn
## LONG FN
### Syntax

LONG FN functionName [(arg1 [,arg2...])]  [statementBlock] END FN [= expr]

### Description

In FB, LONG FN is a synonym for LOCAL FN. Unlike FBII, variables created in a LONG FN are local.

### See Also

FN <userFunction>; LOCAL FN ;END FN