Black-box testing is a method of software testing that examines the functionality of an application based on the specifications.
White box testing is a testing technique, that examines the program structure and derives test data from the program logic/code
Black-box testing is a method of software testing that examines the functionality of an application based on the specifications.
White box testing is a testing technique, that examines the program structure and derives test data from the program logic/code
Abstract
Human–computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use. The field formally emerged out of computer science, cognitive psychology and industrial design through the 1960s, formulating guidelines for the development of interactive computer systems highlighting usability concerns for improved interfaces. Computing devices are becoming more prevalent and integrated into both our social and work spaces.HCI therefore plays an important role in ensuring that computer systems are not only functional but also respect the needs and capabilities of the humans that use them.
HCI encompasses not only ease of use but also new interaction techniques. It involves input and output devices and the interaction techniques that use them; presentation of information, control and monitoring of computer’s actions and the processes that developers follow when creating interfaces. In this seminar, emphasis is laid on the movement of a user’s eyes which can provide a convenient, natural, and high-bandwidth source of additional user input. Some of the human factors and technical considerations that arise in trying to use eye movements as an input medium and the first eye movement-based interaction techniques are discussed in this section.
AYUSHA PATNAIK,
SEM - 6th
TRIDENT ACADEMY OF TECHNOLOGY,
BBSR
Software Architecture for (Robot-Sense, Think and Act ). It is general architecture for mobile robots for performing tasks.
A Layered architecture, use to build standard software by integrating robot subsystems and user logic.
Block-box testing (or functional testing, or behavior testing) focuses on the functional requirements of the software.
Gray box testing is a combination of white and black box testing
Intro to AI STRIPS Planning & Applications in Video-games Lecture6-Part1Stavros Vassos
This is a short course that aims to provide an introduction to the techniques currently used for the decision making of non-player characters (NPCs) in commercial video games, and show how a simple deliberation technique from academic artificial intelligence research can be employed to advance the state-of-the art.
For more information and downloading the supplementary material please use the following links:
http://stavros.lostre.org/2012/05/19/video-games-sapienza-roma-2012/
http://tinyurl.com/AI-NPC-LaSapienza
Data Science - Part XIV - Genetic AlgorithmsDerek Kane
This lecture provides an overview on biological evolution and genetic algorithms in a machine learning context. We will start off by going through a broad overview of the biological evolutionary process and then explore how genetic algorithms can be developed that mimic these processes. We will dive into the types of problems that can be solved with genetic algorithms and then we will conclude with a series of practical examples in R which highlights the techniques: The Knapsack Problem, Feature Selection and OLS regression, and constrained optimizations.
Abstract
Human–computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use. The field formally emerged out of computer science, cognitive psychology and industrial design through the 1960s, formulating guidelines for the development of interactive computer systems highlighting usability concerns for improved interfaces. Computing devices are becoming more prevalent and integrated into both our social and work spaces.HCI therefore plays an important role in ensuring that computer systems are not only functional but also respect the needs and capabilities of the humans that use them.
HCI encompasses not only ease of use but also new interaction techniques. It involves input and output devices and the interaction techniques that use them; presentation of information, control and monitoring of computer’s actions and the processes that developers follow when creating interfaces. In this seminar, emphasis is laid on the movement of a user’s eyes which can provide a convenient, natural, and high-bandwidth source of additional user input. Some of the human factors and technical considerations that arise in trying to use eye movements as an input medium and the first eye movement-based interaction techniques are discussed in this section.
AYUSHA PATNAIK,
SEM - 6th
TRIDENT ACADEMY OF TECHNOLOGY,
BBSR
Software Architecture for (Robot-Sense, Think and Act ). It is general architecture for mobile robots for performing tasks.
A Layered architecture, use to build standard software by integrating robot subsystems and user logic.
Block-box testing (or functional testing, or behavior testing) focuses on the functional requirements of the software.
Gray box testing is a combination of white and black box testing
Intro to AI STRIPS Planning & Applications in Video-games Lecture6-Part1Stavros Vassos
This is a short course that aims to provide an introduction to the techniques currently used for the decision making of non-player characters (NPCs) in commercial video games, and show how a simple deliberation technique from academic artificial intelligence research can be employed to advance the state-of-the art.
For more information and downloading the supplementary material please use the following links:
http://stavros.lostre.org/2012/05/19/video-games-sapienza-roma-2012/
http://tinyurl.com/AI-NPC-LaSapienza
Data Science - Part XIV - Genetic AlgorithmsDerek Kane
This lecture provides an overview on biological evolution and genetic algorithms in a machine learning context. We will start off by going through a broad overview of the biological evolutionary process and then explore how genetic algorithms can be developed that mimic these processes. We will dive into the types of problems that can be solved with genetic algorithms and then we will conclude with a series of practical examples in R which highlights the techniques: The Knapsack Problem, Feature Selection and OLS regression, and constrained optimizations.
The GENETIC ALGORITHM is a model of machine learning which derives its behavior from a metaphor of the processes of EVOLUTION in nature. Genetic Algorithm (GA) is a search heuristic that mimics the process of natural selection. This heuristic (also sometimes called a metaheuristic) is routinely used to generate useful solutions to optimization and search problems.
The genetic algorithm is a mataheuristic method that uses the metaphor of the evolutionary process of living things, especially Darwin's theory of evolution. This persentation will discuss about the fundamental of Genetic Algorithm. Download this PPT and put in "Slide Persentation (F5)" to play the animation in it.
Genetics and the study of human genome is fascinating and has the potential to alter our understanding going back or forward.
Genetics will play a significant role -- atleast as impactful as internet and its effect will be lasting as the wheel. Revolutionary changes are afoot and the world as we know it is over. Much of it is driven by technology. This is a very high level intro to basics of genetics. Lots of reading, consulting genetic experts.
Sheet1Student Name ________________________________10-coin trialO.docxbjohn46
Sheet1Student Name ________________________________10-coin trialObservedExpectedOEO-E(O-E)2(O-E)2/EHeads?5000.0Tails?5000.00.0=Chi Square valueDetermination (select one):Data support that variance in your values is by chance alone (null hypothesis) ORData support that factor(s) other than chance are contributing the result (alternative hypothesis)50-coin trialObservedExpectedOEO-E(O-E)2(O-E)2/EHeads?25000.0Tails?25000.00.0=Chi Square valueDetermination (select one):Data support that variance in your values is by chance alone (null hypothesis) ORData support that factor(s) other than chance are contributing the result (alternative hypothesis)100-coin trialObservedExpectedOEO-E(O-E)2(O-E)2/EHeads?50000.0Tails?50000.00.0=Chi Square valueDetermination (select one):Data support that variance in your values is by chance alone (null hypothesis) ORData support that factor(s) other than chance are contributing the result (alternative hypothesis)
&CTable 1: Chi Square Statistic for Blood Types in Anthropology 201&R&D
&T
ETO&HTGT PLus HTGT&WOTChi-square for EasyToSee Islanders (Observed) and HardtoGetTo Islanders (Expected)OEO-E(O-E)2(O-E)2/EA+0?0.000.000.00A-0?0.000.000.00B+0?0.000.000.00B-0?0.000.000.00O+100?0.000.000.00O-0?0.000.000.00AB+0?0.000.000.00AB-0?0.000.000.000.00=Chi Square valueNote: Because all blood types, except for O+ are not present in the EasyToSee population, I used EasyToSee for observed, this avoids denominators of zeroNote: Be sure to use the actual number of persons and not the frequencies for each blood typeDetermination (select one):Data support that variance in your values is by chance alone (null hypothesis) ORData support that factor(s) other than chance are contributing the result (alternative hypothesis)Chi-square for HardtoGetTo Islanders (Observed) and WayOutThere Islanders (Expected)OEO-E(O-E)2(O-E)2/EA+?310.000.000.00A-?50.000.000.00B+?10.000.000.00B-?10.000.000.00O+?10.000.000.00O-?10.000.000.00AB+?430.000.000.00AB-?170.000.000.000.000=Chi Square valueDetermination (select one):Data support that variance in your values is by chance alone (null hypothesis) ORData support that factor(s) other than chance are contributing the result (alternative hypothesis)
&CTable 1: Chi Square Statistic for Blood Types in Anthropology 201&R&D
&T
ETS&WOTChi-square for EasyToSee Islanders (Observed) and WayOutThere Islanders (Expected)OEO-E(O-E)2(O-E)2/EA+031-31.00961.0031.00A-05-5.0025.005.00B+01-1.001.001.00B-01-1.001.001.00O+100199.009801.009801.00O-01-1.001.001.00AB+043-43.001849.0043.00AB-017-17.00289.0017.009900.00=Chi Square valueNote: Because all blood types, except for O+ are not present in the EasyToSee population, I used EasyToSee for observed, this avoids denominators of zeroNote: Be sure to use the actual number of persons and not the frequencies for each blood typeDetermination (select one):Data support that variance in your values is by chance alone (null hypothesis) ORData support that factor(s) othe.
1. What is your reaction to Kant applying his idea of a categorialBenitoSumpter862
1. What is your reaction to Kant applying his idea of a categorial imperative to international politics? In other words, do you think that a rational logic leads people to cooperate, knowing that we are all better off cooperating? Or does fear/insecurity, vanity, ambition, etc. lead actors to what could be argued an illogical path to conflict?
2. How well do you think Doyle’s Liberalist argument for a Kantian Internationalism holds up against the Realist logic of security-seeking States being in a perpetual state of competition and conflict—regardless of whether they are liberal, capitalist democracies or not?
3. Between Neo-Realism and Neo-Liberalism, which theory is better able to explain outcomes in international politics? Explain your answer.
Econometrics PS 1
Due: Feb 2
Complete the entire problems in each section as required. There are two sections!
Section 1: Probability theory: Expected Value and Lotteries (ONE QUESTION TOTAL)
We discussed how the sample mean can be skewed by an extreme value. In a sample of 100 people from Texas, if a multi-millionaire oil baron is randomly chosen for the sample, the mean income in the sample would be skewed higher than the median.
The sample mean is sometimes referred to as the expected value, written E[X] for the expected value of X. In probability theory the expected value is the sum of all potential outcomes, weighted by the probability/chance of the occurrence. For example, assume you are close friends with the oil baron. You need money for school, and as your friend he will agrees to give you one of two cars he never drives, which you will immediately sell for cash. He will flip a coin to determine which one, giving you a 50/50 chance of each. Let’s say one car is worth $12,000 and the other car is worth $118,000. The expected value is written E[X] = 0.5 × $12,000 + 0.5 × $118,000 = $65,000. Notice that this is also the average of the two values.
Question 1: Consider a random lottery, where 2,250 people enter their name (only once per-person) and a machine selects one winner at random. Each player has an equal chance of selection and the winning prize is $425,000.
a. Absent any costs associated with winning or playing the lottery, what is the expected value of entering the lottery one time?
b. Assume the winner must pay a 20% tax on lottery winnings. Further, the dealer wants to charge an entry fee. Exactly 2,250 people believe in luck and will play if the expected value of the gamble is greater than or equal to zero. What is the maximum entry fee the dealer can charge? Will the dealer make a profit?
c. What is the fundamental difference between the typical Powerball or Megamillions lottery and the one we established in our example above? Use two sentences or less to explain.
Section 2:Stata Exercises (FIVE QUESTIONS TOTAL)
For this section you will download data from this site: https://www.stata.com/texts/eacsap/
Connect to the virtual Stata console here: https://vcon.lib.uh.edu/ ...
1. What is your reaction to Kant applying his idea of a categorialSantosConleyha
1. What is your reaction to Kant applying his idea of a categorial imperative to international politics? In other words, do you think that a rational logic leads people to cooperate, knowing that we are all better off cooperating? Or does fear/insecurity, vanity, ambition, etc. lead actors to what could be argued an illogical path to conflict?
2. How well do you think Doyle’s Liberalist argument for a Kantian Internationalism holds up against the Realist logic of security-seeking States being in a perpetual state of competition and conflict—regardless of whether they are liberal, capitalist democracies or not?
3. Between Neo-Realism and Neo-Liberalism, which theory is better able to explain outcomes in international politics? Explain your answer.
Econometrics PS 1
Due: Feb 2
Complete the entire problems in each section as required. There are two sections!
Section 1: Probability theory: Expected Value and Lotteries (ONE QUESTION TOTAL)
We discussed how the sample mean can be skewed by an extreme value. In a sample of 100 people from Texas, if a multi-millionaire oil baron is randomly chosen for the sample, the mean income in the sample would be skewed higher than the median.
The sample mean is sometimes referred to as the expected value, written E[X] for the expected value of X. In probability theory the expected value is the sum of all potential outcomes, weighted by the probability/chance of the occurrence. For example, assume you are close friends with the oil baron. You need money for school, and as your friend he will agrees to give you one of two cars he never drives, which you will immediately sell for cash. He will flip a coin to determine which one, giving you a 50/50 chance of each. Let’s say one car is worth $12,000 and the other car is worth $118,000. The expected value is written E[X] = 0.5 × $12,000 + 0.5 × $118,000 = $65,000. Notice that this is also the average of the two values.
Question 1: Consider a random lottery, where 2,250 people enter their name (only once per-person) and a machine selects one winner at random. Each player has an equal chance of selection and the winning prize is $425,000.
a. Absent any costs associated with winning or playing the lottery, what is the expected value of entering the lottery one time?
b. Assume the winner must pay a 20% tax on lottery winnings. Further, the dealer wants to charge an entry fee. Exactly 2,250 people believe in luck and will play if the expected value of the gamble is greater than or equal to zero. What is the maximum entry fee the dealer can charge? Will the dealer make a profit?
c. What is the fundamental difference between the typical Powerball or Megamillions lottery and the one we established in our example above? Use two sentences or less to explain.
Section 2:Stata Exercises (FIVE QUESTIONS TOTAL)
For this section you will download data from this site: https://www.stata.com/texts/eacsap/
Connect to the virtual Stata console here: https://vcon.lib.uh.edu/ ...
An introduction to programming genetic algorithms, using the Travelling Salesman problem as an example. Lecture given as part of the Caltech-JPL Big Data Analytics online course.
Artificial Intelligence lecture notes. AI summarized notes for introduction to machine learning, symbol based and constructionist learning, also deep learning organized here for reading and may be for self-learning, I think.
Artificial Intelligence lecture notes. AI summarized notes on uncertainty and handling it through fuzzy logic, tipping problem scenarios are seen in it, for reading and may be for self-learning, I think.
Artificial Intelligence lecture notes. AI summarized notes for expert systems, inference mechanisms and so on, this is reading and may be for self-learning, I think.
Lec 3 knowledge acquisition representation and inferenceEyob Sisay
Artificial Intelligence lecture notes. AI summarized notes for knowledge reasoning and knowledge representation, its for you in order for reading and may be for self-learning, I think.
Artificial Intelligence lecture notes. AI summarized notes for heuristically informed searches and types of searches in ai ( ai search algorithms ) and machine learning as well, just for reading and may be for self-learning, I think.
Security and Privacy Challenges in Cloud Computing EnvironmentsEyob Sisay
Unique Security and Privacy Implications, Analyzing Route Security Properties and Open Areas for Research in Cloud Computing starting from its characteristics like: on-demand (it functions when needed), rapid elasticity (scaling up or down) and resource utilization enhances by automated resource allocation, load balancing, and metering tools.
A Survey on Wireless Mesh Networks (WMN)Eyob Sisay
The network architectures of WMNs, Critical factors influencing protocol design or its design factors and Open Areas for Research on WMNs are discussed in this slide.
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Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
2. 2
Evolution
Oversimplified description of how evolution works in biology:
Organisms (animals or plants) produce a number of offspring
which are almost, but not entirely, like themselves
Variation may be due to mutation (random changes)
Variation may be due to sexual reproduction (offspring have some
characteristics from each parent)
Some of these offspring may survive to produce offspring of their
own—some won’t
The “better adapted” offspring are more likely to survive
Over time, later generations become better and better adapted
Genetic algorithms use this same process to “evolve” better
programs
3. 3
Genotypes and phenotypes
Genes are the basic “instructions” for building an
organism
A chromosome is a sequence of genes
Biologists distinguish between an organism’s genotype
(the genes and chromosomes) and its phenotype (what
the organism actually is like)
Example: You might have genes to be tall, but never grow to
be tall for other reasons (such as poor diet)
Similarly, “genes” may describe a possible solution to a
problem, without actually being the solution
4. 4
The basic genetic algorithm
Start with a large “population” of randomly generated
“attempted solutions” to a problem
Repeatedly do the following:
Evaluate each of the attempted solutions
Keep a subset of these solutions (the “best” ones)
Use these solutions to generate a new population
Quit when you have a satisfactory solution (or you run out of time)
6. 6
A really simple example
Suppose your “organisms” are 32-bit computer words
You want a string in which all the bits are ones
Here’s how you can do it:
Create 100 randomly generated computer words
Repeatedly do the following:
Count the 1 bits in each word
Exit if any of the words have all 32 bits set to 1
Keep the ten words that have the most 1s (discard the rest)
From each word, generate 9 new words as follows:
Pick a random bit in the word and toggle (change) it
Note that this procedure does not guarantee that the next
“generation” will have more 1 bits, but it’s likely
7. 7
A more realistic example, part I
Suppose you have a large number of (x, y) data points
For example, (1.0, 4.1), (3.1, 9.5), (-5.2, 8.6), ...
You would like to fit a polynomial (of up to degree 5) through
these data points
That is, you want a formula y = ax5 + bx4 + cx3 + dx2 +ex + f that gives
you a reasonably good fit to the actual data
Here’s the usual way to compute goodness of fit:
Compute the sum of (actual y – predicted y)2 for all the data points
The lowest sum represents the best fit
There are some standard curve fitting techniques, but let’s assume
you don’t know about them
You can use a genetic algorithm to find a “pretty good” solution
8. 8
A more realistic example, part II
Your formula is y = ax5 + bx4 + cx3 + dx2 +ex + f
Your “genes” are a, b, c, d, e, and f
Your “chromosome” is the array [a, b, c, d, e, f]
Your evaluation function for one array is:
For every actual data point (x, y), ( red to mean “actual data”)
Compute ý = ax5 + bx4 + cx3 + dx2 +ex + f
Find the sum of (y – ý)2 over all x
The sum is your measure of “badness” (larger numbers are worse)
Example: For [0, 0, 0, 2, 3, 5] and the data points (1, 12) and (2, 22):
ý = 0x5 + 0x4 + 0x3 + 2x2 +3x + 5 is 2 + 3 + 5 = 10 when x is 1
ý = 0x5 + 0x4 + 0x3 + 2x2 +3x + 5 is 8 + 6 + 5 = 19 when x is 2
(12 – 10)2 + (22 – 19)2 = 22 + 32 = 13
If these are the only two data points, the “badness” of [0, 0, 0, 2, 3, 5] is 13
9. 9
A more realistic example, part III
Your algorithm might be as follows:
Create 100 six-element arrays of random numbers
Repeat 500 times (or any other number):
For each of the 100 arrays, compute its badness (using all data
points)
Keep the ten best arrays (discard the other 90)
From each array you keep, generate nine new arrays as
follows:
Pick a random element of the six
Pick a random floating-point number between 0.0 and 2.0
Multiply the random element of the array by the random
floating-point number
After all 500 trials, pick the best array as your final answer
10. 10
Asexual vs. sexual reproduction
In the examples so far,
Each “organism” (or “solution”) had only one parent
Reproduction was asexual (without sex)
The only way to introduce variation was through mutation
(random changes)
In sexual reproduction,
Each “organism” (or “solution”) has two parents
Assuming that each organism has just one chromosome, new
offspring are produced by forming a new chromosome from
parts of the chromosomes of each parent
11. 11
The really simple example again
Suppose your “organisms” are 32-bit computer words,
and you want a string in which all the bits are ones
Here’s how you can do it:
Create 100 randomly generated computer words
Repeatedly do the following:
Count the 1 bits in each word
Exit if any of the words have all 32 bits set to 1
Keep the ten words that have the most 1s (discard the rest)
From each word, generate 9 new words as follows:
Choose one of the other words
Take the first half of this word and combine it with the
second half of the other word
12. 12
The example continued
Half from one, half from the other:
0110 1001 0100 1110 1010 1101 1011 0101
1101 0100 0101 1010 1011 0100 1010 0101
0110 1001 0100 1110 1011 0100 1010 0101
Or we might choose “genes” (bits) randomly:
0110 1001 0100 1110 1010 1101 1011 0101
1101 0100 0101 1010 1011 0100 1010 0101
0100 0101 0100 1010 1010 1100 1011 0101
Or we might consider a “gene” to be a larger unit:
0110 1001 0100 1110 1010 1101 1011 0101
1101 0100 0101 1010 1011 0100 1010 0101
1101 1001 0101 1010 1010 1101 1010 0101
13. 13
Comparison of simple examples
In the simple example (trying to get all 1s):
The sexual (two-parent, no mutation) approach, if it succeeds,
is likely to succeed much faster
Because up to half of the bits change each time, not just one bit
However, with no mutation, it may not succeed at all
By pure bad luck, maybe none of the first (randomly generated) words
have (say) bit 17 set to 1
Then there is no way a 1 could ever occur in this position
Another problem is lack of genetic diversity
Maybe some of the first generation did have bit 17 set to 1, but
none of them were selected for the second generation
The best technique in general turns out to be sexual
reproduction with a small probability of mutation
14. 14
Curve fitting with sexual reproduction
Your formula is y = ax5 + bx4 + cx3 + dx2 +ex + f
Your “genes” are a, b, c, d, e, and f
Your “chromosome” is the array [a, b, c, d, e, f]
What’s the best way to combine two chromosomes into
one?
You could choose the first half of one and the second half of
the other: [a, b, c, d, e, f]
You could choose genes randomly: [a, b, c, d, e, f]
You could compute “gene averages:”
[(a+a)/2, (b+b)/2, (c+c)/2, (d+d)/2, (e+e)/2,(f+f)/2]
The last may be the best, though it is difficult to know of a good
biological analogy for it
15. Three main types of rules
The genetic algorithm uses three main types of
rules at each step to create the next generation
from the current population:
• Selection rules select the individuals, called parents, that
contribute to the population at the next generation.
• Crossover rules combine two parents to form children
for the next generation.
• Mutation rules apply random changes to individual
parents to form children.
15
16. 16
Directed evolution
Notice that, in the previous examples, we formed the
child organisms randomly
We did not try to choose the “best” genes from each parent
This is how natural (biological) evolution works
Biological evolution is not directed—there is no “goal”
Genetic algorithms use biology as inspiration, not as a set of
rules to be slavishly followed
For trying to get a word of all 1s, there is an obvious
measure of a “good” gene
But that’s mostly because it’s a silly example
It’s much harder to detect a “good gene” in the curve-fitting
problem, harder still in almost any “real use” of a genetic
algorithm
17. 17
Probabilistic matching
In previous examples, we chose the N “best” organisms
as parents for the next generation
A more common approach is to choose parents
randomly, based on their measure of goodness
Thus, an organism that is twice as “good” as another is likely
to have twice as many offspring
This has a couple of advantages:
The best organisms will contribute the most to the next
generation
Since every organism has some chance of being a parent, there
is somewhat less loss of genetic diversity
18. 18
Genetic programming
A string of bits could represent a program
If you want a program to do something, you might try to
evolve one
As a concrete example, suppose you want a program to
help you choose stocks in the stock market
There is a huge amount of data, going back many years
What data has the most predictive value?
What’s the best way to combine this data?
A genetic program is possible in theory, but it might
take millions of years to evolve into something useful
How can we improve this?
19. 19
Concluding remarks
Genetic algorithms are—
Fun! They are enjoyable to program and to work with
This is probably why they are a subject of active research
Mind-bogglingly slow—you don’t want to use them if you
have any alternatives
Good for a very few types of problems
Genetic algorithms can sometimes come up with a solution when you
can see no other way of tackling the problem