Notesale: Turn your study into money

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General Notes
9/08/16
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How does a CCTV system work?
Multiple cameras have cords that send moving images to monitors, which is stored on a disk drive
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How is data collected and stored and accessed?

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What are some of the advantages (and for whom?)
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It might
lead to over population of prisons, especially if you're in a really shady low-income country,
athough this might not happen
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6 The digital divide and equality of access
The growth of the use of IT systems has led to disparities in the use of, and access to, information
technologies
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This may lead to groups or individuals without access to IT being
disadvantaged
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17/08/18
Distributed Systems & Autonomous Agents
Comparison Table of Centralized vs Distributed
Centralized has one main source
Distributed they hae their own points of processing, share data but not programing and processing
resoources
Distributed
Software on a central system runs on a mainframe
In a distributed system, think about it as an autonomous agent that is sharing
Consists of autonomous gents that are acting as part of a large envneronemtn
Centralized

Distributed

Topic 7 Page 1

• One component with non-autonomous parts
Component shared by all users all the time
All resources abailable
Software runs in a single process

Single point of control
Single point of failure
Pros and Cons of distributed computing

Pros

Cons

Costs - cheaper than
running a supercomputer

Network Bandiwdth - bottlenecking can
happen if a lot fo data is being ransferred at
once

Perofrmance - if sufficient
computers are connected,
performance is far greater
than a supercomputer

Security - if a projcet has potentially
sensitive information included it can
potentially cause a security breahc

Reliability - if one or two
computers go offline it is
not going to have a huge
effect on the overall
processing of information
because all the other
comptuers are still online
and running the analysis

Softwware complexity - software has to be
written for the project and the sofware may
put peple off if it comes across too
complicated

Socalalbility - it is very easy
to increase the amount of
processing power due to
the nature of the software
Autonomous Agents
An autonomous agent is an inteilligent agent operating on an owner's behalvf but without any
interference of that ownership entity
It could be hardware or software that carries out some set of operaions on behalf of a user or
another program with some degree of independece or autonomoy that does what the user wants it
to do
e
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autonomous robots, computer viruses, artificial life
Features of an autonomos agent
Autonomy - agents activiate alone f roa atask and are not invoked
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Organised Notes

Specifically: automated doors, heating systems, taxi meters, elevators, washing machines, process control,
device drivers, GPS systems, traffic lights and other common devices
A control system is a device, or set of devices, that manages, commands, directs or regulates the behaviour
of other devices or systems
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Microprocessor is an integrated circuit that contains all the functions of a central processing unit of a
computer
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3 Evaluate different input
devices for the collection of data
in specified situations
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4 Explain the relationship
between a sensor, the processor
and an output transducer
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Digital data can then be processed by a
microprocessor, producing digital output
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5 Describe the role of
feedback in a control system
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6 Discuss the social impacts
and ethical considerations
associated with the use of
embedded systems
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Tagging Prisoners

Surveillance
CCTV (Closed Circuit Television)

Topic 7 Page 3

Range of Control Systems
A control system is one or more devices that guide other devices or systems
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Control systems are set up and then perform actions that they have to do, in an automatic manner
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Control systems are input, process, output systems
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Sensors measure the results of the action, and feedback is provided as input
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Interrupts are sent to the control system in order to indicate that the system needs to attend to the specific signal immediately
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Automatic Doors
A motion sensor is located at the top of the automatic doors, which allows the control system to become aware of motion
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After receiving feedback from the environment, the sensor forwards its signal to a
microprocessor and allows the control system to operate its actuators
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More advanced automatic doors
include photocell sensors that can tell if someone is at the door, so that the doors do not close on them
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Automatic doors adds to accessibility, as the elderly or disabled might find it difficult to open or close a
manual door
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Heating system
In any heating system, an initial temperature is given as the user input (e
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24°C)
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Sensors allow the control system to measure the temperature of the environment and determine what it needs to do to reach the desired
temperature
...
g
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Once the sensor temperature reaches the desired temper ature, the heater would
turn off
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Having a control system conserves energy and is more efficient than manually turning a heating system on and off
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On the other hand, in a manual system, every time the
temperature fell or rose above the desired temperature, there would be a greater waste of energy as the user has to manually turn the system on or off
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Seat sensors detect passengers in o rder to prevent passenger journeys
that don't require the taximeter
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Credit cards are supported, as well as radio communication and GPS
systems
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It relieves the driver from hassle that could distract them from driving
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The sys tem reads the desired destination from
the user and uses sensors to detect the current location, as well as the location of each floor
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There may also b e a load sensor that indicates how
full the car is
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A stop button is included to stop the el evator car from moving in emergency
situations
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Washing machines
In modern washing machines, sensors are used to determine and control the load size, water level, temperature, as well as the user interface
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It also is more environmentally friendly, since it con sumes less electricity and water
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If the door is opened before the
washing machine is finished or if the stop button is pressed, an interrupt signal is sent to the control system's processor, which requests its immediate attention
and stops the washing machine
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The purpose of process control is to maintain the output of a specific process within a
desired range
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Control systems allow for the automatic adjustments of a process in or der to achieve the desired value,
with minimal or no human interaction
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Device drivers
Device drivers are computer programs used to control a computer device of any kind, such as keyboards and printers
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Since drivers are develoed specifically for each device, they are hardwaredependent and operating-system specific, so that they are as efficient as possible
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Sensors are packed within these robots to provide "intelligent"
behaviour
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They can return to their
charging base whenever needed, and complete the cleaning afterwards
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Sensors can detect the material the robot is currently cleaning on and perform the
appropriate tasks needed for it (e
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appropriate cleaning)
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GPS Systems
GPS systems are required to work efficiently, precisely, and with no down time
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This system uses around 30 satellites in orbit around the Earth, as well as a number of extra satellites that are fail-safes
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It has a sensor that locates four or more GPS satellites, figures out its distance to each one,
calculates the time difference between the satellites and uses trilateration to deduce its location
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Traffic Lights
Traffic lights manage traffic, prevent accidents, and allow pedestrians to cross the roads
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Fixed time traffic lights are open loop control systems that do not receive any feedback from the environment to alter their performance
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Fixed time traffic lights can be implemen ted with an electro-mechanical
signal controller and does not need a computer system
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Dynamic control traffic lights can adapt their
settings appropriately, following some algorithm
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Their sensors can be embedded in to the surface of the road or
mounted on the traffic light itself
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Mounted
sensors are less expensive and can provide the same feedback
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A microprocessor
performs arithmetic and logic operations, as well as any other data operations necessary like a CPU
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Various types of microprocessors exist
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They are normally in larger systems
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Embedded controller or microcontrollers are usually stand-alone chips that may include the main elements of a larger system, such as RAM and ROM
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Control systems use microcontrollers to
function in an efficient and timely manner
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Graphics processing unit (GPU) are a special kind of microprocessor that includes hardware to allow for faster handling of graphics related mathematics
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Microprocessors process data much faster than a human and they react to changes in the input quickly
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They can operate throughout the year with little to no down time and in conditions that are
harsh or dangerous for humans
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Since microprocessors need power to operate, the system would not be
able to function if there was a power shortage
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A sensor converts continuous physical (analogue) quantities into discrete digital signals using an
analogue-to-digital converter (ADC)
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The input is processed, according to some algortihm, and the
output is returned
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(e
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a temperature of
18°C should not be measured as 19°C)
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(e
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a temperature sensor might be
accurate in the -30°C to 60°C range, but not accurate above and below the range)
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(e
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detecting temperature in increments of 0
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Sensors have two more characteristics that makes sure that their readings aren't useless
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g
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Secondly, the sensors should not influence the measured quantity in any way
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g
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Analogue to Digital Conversion
An ADC is used by every system that uses sensors to convert continuous analogue data to discrete digital signals handled by a microprocessor
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The data converted by the ADCs and handled by the microprocessor is actually a sample of the
actual physical quantity being measured
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Analogue data is continously changing data
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The
more samples you take the more accurate the digital representaton
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Sound engineers use a 44100Hz sample rate to digitise analogue sound
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Topic 7 Page 6

Different Input Devices
Sensors are important in control systems and act as input devices
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Sensors measure a physical
attribute and then transform it into an electrical signal
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Motion sensors detect moving objects and are used in security/alarm systems
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Vibration sensors detect vibrations and are place on surfaces that can vibrate
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Optical/Image sensors
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Infrared (IR) sensors are used to sense invisible radiant energy with longer wavelengths than those of visible light
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Pressure sensors detect pressure and are used in a variety of settings
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Temperature sensors detect temperature and are used in thermostats to control the temperature of a given setting
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They are used in cars to help drivers reverse or park
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Transducers convert one form of energy to another
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This conversion process
from one form of energy to another is called transduction
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Other devices can also be transducers
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Actuators are devices responsible for moving some kind of
mechanism
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The above diagram is how a control system works as an input, process and output device
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The sensor is a transducer, because it converts one form of energy to another
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After the processor does the necessary processing, it
outputs an electronic signal
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The actuator will convert the electrical signal into motion
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Topic 7 Page 8

Role of Feedback in a Control System
There are two types of control systems: Open loop systems and feedback systems
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A microwave will run for a set amount of time and switch off
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Feedback refers to the process where information about the result of an output, from a control system, is used as part of the new input to the
control system in order to determine the best course of action for the next output
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Feedback helps keep the system in a stable,
working state
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Overcrowding of correctional facilities impacts their ability to provie effective rehabiliation
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The
GPS allows correctional officers to monitor their location at all times
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Benefits:
• Reduces crime rates as offenders are less likely to reoffend
• Makes police officers solve crimes faster, which saves the time of court rooms and lawyers
• Saves prison cells and there is less need for creationg more correctional facilities
• Could improve rehiabilitation and reintegration of offenders, as they are leaving correctional facilities sooner
• Has multiple uses on people with memory loss and immigrants
Limitations:
• Might not be a severe enough punishment for the criminal
• Does not physically restrain offenders from commiting more crimes
• Needs a large task force of individuals that can monitor criminals and intervene when necessary
• Wearing the tag may add psychological pressure to the wearer

Surveillance, CCTV
CCTV cameras are everywhere, on highways and cities around the world
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People don't often notice their exitence
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Most forms of electronic surveillance systems are embedded control systems
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g
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Issues:
• Loss of privacy if an area has too many cameras
• Misuse of information gained from CCTV cameras
• Whether surveillance is actually effective in reducing crime
• Whether workplcaes should install surveillance to monitor their workers
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• Whether the right to privacy is more important than preventing potential crimes
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Everyday life is full of unexpected events, and so safety systems improve in order to anticipate them as
much as possible
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A warning light comes on and the elevator does not move until enough
people have left
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Topic 7 Page 10

ITGS Social & Ethical Issues
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Data may be
unreliable if it has been entered incorrectly or if it becomes outdated
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Integrity refers to safeguarding the accuracy and completeness of stored data
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Examples of data losing integrity are where information is duplicated in a relational database and only one copy is updated o r where data entries have been
maliciously altered
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2 Security
Security refers to the protection of hardware, software, machines and networks from unauthorized access
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The degree of security of information systems largely determines society’s confidence in the
information contained in the systems
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3 Privacy and anonymity
Privacy is the ability of individuals and groups to determine for themselves when, how and to what extent information about themselves is shared with others
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Conversely,
excessive privacy could also conceal the perpetrators of criminal, terrorist or computer hacking acts from law enforcement agencies
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4 Intellectual property
Intellectual property includes ideas, discoveries, writings, works of art, software, collections and presentations of data
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However, the easy and accurate duplication methods made available through IT can undermine such protection
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5 Authenticity
Authenticity means establishing a user’s identity beyond reasonable doubt
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A simple example of authentication is a user login to a network
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Disparities exist not only internationally between
countries, but also within countries between different socio-economic groups as well as within what may appear to be relatively homogenous groups
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For example, while telelearning may bring previously unavailable opportunities to everyone’s
doorstep, factors such as the cost and availability of hardware, software or access to the internet may create a “digital divide”
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7 Surveillance
Surveillance is the use of IT to monitor the actions of people
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It can be
used to support claims for promotion or to ensure that employees follow the organization’s internet policy appropriately
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8 Globalization and cultural diversity
Globalization means the diminishing importance of geographical, political, economic and cultural boundaries
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For example, any dramatic event anywhere in the world can be broadcast almost instantly by television or on the i nternet
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They can be developed
by governments, businesses, private groups or individuals
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For example, a school policy on the use of IT would consist of each user signing an acceptable use policy
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Many websites also require users to agree to
specific policies before allowing access to their services
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In general, policies can promote or restrict access, guide behaviour, require the fulfillment of certain conditions prior to or
during use, or need to be developed to address unforeseen issues such as cyber-bullying
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10 Standards and protocols
Standards and protocols are technical rules and conventions that enable compatibility and therefore facilitate communication or interoperability between different
IT systems and their components
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For example, the communication protocols used on
the internet, the ASCII representations for characters, or the design of the printer port on a personal computer are all governed by standards
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11 People and machines
The use of IT systems brings significant advantages, for instance in ease of use, being available 24/7, or through its use rather than exposing humans to a potentially
hazardous environment
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The ultimate fear of many people is that future systems will be programme d to make decisions that would be better
taken by humans, such as the decision to deploy nuclear weapons
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Digital citizenship permeates, in one way or another, all of the preceding social and ethical considerations
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Organised Notes
Centralised system is computing done at a central location, using terminals that are attached to a central
computer
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Distributed system is a system in which components located on networked computers communicate and
coordinate their actions by passing messages
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8 Outline the role of
autonomous agents acting
within a larger system
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Topic 7 Page 12

Centrally Controlled Systems vs Distributed Systems
A centrally controlled system is a system with a dedicated computer system that is responsible for all the necessary calculations, as well as anything else that
needs to be performed so that the control system can function
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Each system is self-sustaining for the most part
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• Easily expendible as self-sustained systems may be added or removed at any point in time without affecting the overall system
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Increases cost
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• Security can be an issue, since there are more systems to secure
Distributed systems require additional hardware that increases the cost of the whole system
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This means that the cost between each system may vary
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Topic 7 Page 13

Role of Autonomous Agents
Agents can be anything that can perceive its environment, through sensors, and act upon it, through effectors
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These
agents follow algorithms supplied by the owner to achieve a desired goal
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The environment within which agents operate plays a significant role in the design, implementation, and
effectiveness of the agents
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Characteristic

Description

Accessible/Inaccessible

Whether complete and accurate information of the environment is obtainable
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In a
deterministic enviroment, the next state of the environment is determined by its current state and the agent's action
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Episodic/Non-Episodic

Whether an agent's actions are divided into "episodes" or not
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Most real world environments are non-episodic, in that the agent's earlier action affect the future actions
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Most real world environments are dynamic, in that an
environment is independent of the agent and does not wait for an agent's action before it changes
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Most real world
environments fall under the continuous category

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