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GNU/Linux AI & Alife HOWTO
GNU/Linux AI & Alife HOWTO GNU/Linux AI & Alife HOWTO Table of Contents GNU/Linux AI & Alife HOWTO......................................................................................................................1 by John Eikenberry..................................................................................................................................1 1. Introduction..........................................................................................................................................1 2. Symbolic Systems (GOFAI)................................................................................................................1 3. Connectionism.....................................................................................................................................1 4. Evolutionary Computing......................................................................................................................1 5. Alife & Complex Systems...................................................................................................................1 6. Agents & Robotics...............................................................................................................................1 7. Statistical & Machine Learning...........................................................................................................2 8. Missing & Dead...................................................................................................................................2 1. Introduction.........................................................................................................................................2 -
The Origins of the Underline As Visual Representation of the Hyperlink on the Web: a Case Study in Skeuomorphism
The Origins of the Underline as Visual Representation of the Hyperlink on the Web: A Case Study in Skeuomorphism The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Romano, John J. 2016. The Origins of the Underline as Visual Representation of the Hyperlink on the Web: A Case Study in Skeuomorphism. Master's thesis, Harvard Extension School. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:33797379 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA The Origins of the Underline as Visual Representation of the Hyperlink on the Web: A Case Study in Skeuomorphism John J Romano A Thesis in the Field of Visual Arts for the Degree of Master of Liberal Arts in Extension Studies Harvard University November 2016 Abstract This thesis investigates the process by which the underline came to be used as the default signifier of hyperlinks on the World Wide Web. Created in 1990 by Tim Berners- Lee, the web quickly became the most used hypertext system in the world, and most browsers default to indicating hyperlinks with an underline. To answer the question of why the underline was chosen over competing demarcation techniques, the thesis applies the methods of history of technology and sociology of technology. Before the invention of the web, the underline–also known as the vinculum–was used in many contexts in writing systems; collecting entities together to form a whole and ascribing additional meaning to the content. -
TRABAJO DE DIPLOMA Título: Diseño De La Página Web De Antenas
FACULTAD DE INGENIERÍA ELÉCTRICA Departamento de Telecomunicaciones y Electrónica TRABAJO DE DIPLOMA Título: Diseño de la Página Web de Antenas Autor: Alaín Hidalgo Burgos Tutor: Dr. Roberto Jiménez Hernández Santa Clara 2006 “Año de la Revolución Energética en Cuba” Universidad Central “Marta Abreu” de Las Villas FACULTAD DE INGENIERÍA ELÉCTRICA Departamento de Telecomunicaciones y Electrónica TTRRAABBAAJJOO DDEE DDIIPPLLOOMMAA Diseño de la Página Web de Antenas Autor: Alaín Hidalgo Burgos e-mail: [email protected] Tutor: Dr. Roberto Jiménez Hernández Prof. Dpto. de Telecomunicaciones y electrónica Facultad de Ing. Eléctrica. UCLV. e-mail: [email protected] Santa Clara Curso 2005-2006 “Año de la Revolución Energética en Cuba” Hago constar que el presente trabajo de diploma fue realizado en la Universidad Central “Marta Abreu” de Las Villas como parte de la culminación de estudios de la especialidad de Ingeniería en Telecomunicaciones y Electrónica, autorizando a que el mismo sea utilizado por la Institución, para los fines que estime conveniente, tanto de forma parcial como total y que además no podrá ser presentado en eventos, ni publicados sin autorización de la Universidad. Firma del Autor Los abajo firmantes certificamos que el presente trabajo ha sido realizado según acuerdo de la dirección de nuestro centro y el mismo cumple con los requisitos que debe tener un trabajo de esta envergadura referido a la temática señalada. Firma del Tutor Firma del Jefe de Departamento donde se defiende el trabajo Firma del Responsable de Información Científico-Técnica PENSAMIENTO “El néctar de la victoria se bebe en la copa del sacrificio” DEDICATORIA Dedico este trabajo a mis padres, a mí hermana y a mi novia por ser las personas más hermosas que existen y a las cuales les debo todo. -
Just Another Perl Hack Neil Bowers1 Canon Research Centre Europe
Weblint: Just Another Perl Hack Neil Bowers1 Canon Research Centre Europe Abstract Weblint is a utility for checking the syntax and style of HTML pages. It was inspired by lint [15], which performs a similar function for C and C++ programmers. Weblint does not aspire to be a strict SGML validator, but to provide helpful comments for humans. The importance of quality assurance for web sites is introduced, and one particular area, validation of HTML, is described in more detail. The bulk of the paper is devoted to weblint: what it is, how it is used, and the design and implementation of the current development version. 1. Introduction The conclusion opens with a summary of the information and opinions given in this paper. A Web sites are becoming an increasingly critical part of selection of the lessons learned over the last four years how many companies do business. For many companies is given, followed by plans for the future, and related web sites are their business. It is therefore critical that ideas. owners of web sites perform regular testing and analysis, to ensure quality of service. 2. Web Site Quality Assurance There are many different checks and analyses which The following are some of the questions you should be you can run on a site. For example, how usable is your asking yourself if you have a web presence. I have site when accessed via a modem? An incomplete list of limited the list to those points which are relevant to similar analyses are given at the start of Section 2. -
CS101 Lecture 9
How do you copy/move/rename/remove files? How do you create a directory ? What is redirection and piping? Readings: See CCSO’s Unix pages and 9-2 cp option file1 file2 First Version cp file1 file2 file3 … dirname Second Version This is one version of the cp command. file2 is created and the contents of file1 are copied into file2. If file2 already exits, it This version copies the files file1, file2, file3,… into the directory will be replaced with a new one. dirname. where option is -i Protects you from overwriting an existing file by asking you for a yes or no before it copies a file with an existing name. -r Can be used to copy directories and all their contents into a new directory 9-3 9-4 cs101 jsmith cs101 jsmith pwd data data mp1 pwd mp1 {FILES: mp1_data.m, mp1.m } {FILES: mp1_data.m, mp1.m } Copy the file named mp1_data.m from the cs101/data Copy the file named mp1_data.m from the cs101/data directory into the pwd. directory into the mp1 directory. > cp ~cs101/data/mp1_data.m . > cp ~cs101/data/mp1_data.m mp1 The (.) dot means “here”, that is, your pwd. 9-5 The (.) dot means “here”, that is, your pwd. 9-6 Example: To create a new directory named “temp” and to copy mv option file1 file2 First Version the contents of an existing directory named mp1 into temp, This is one version of the mv command. file1 is renamed file2. where option is -i Protects you from overwriting an existing file by asking you > cp -r mp1 temp for a yes or no before it copies a file with an existing name. -
The Different Unix Contexts
The different Unix contexts • User-level • Kernel “top half” - System call, page fault handler, kernel-only process, etc. • Software interrupt • Device interrupt • Timer interrupt (hardclock) • Context switch code Transitions between contexts • User ! top half: syscall, page fault • User/top half ! device/timer interrupt: hardware • Top half ! user/context switch: return • Top half ! context switch: sleep • Context switch ! user/top half Top/bottom half synchronization • Top half kernel procedures can mask interrupts int x = splhigh (); /* ... */ splx (x); • splhigh disables all interrupts, but also splnet, splbio, splsoftnet, . • Masking interrupts in hardware can be expensive - Optimistic implementation – set mask flag on splhigh, check interrupted flag on splx Kernel Synchronization • Need to relinquish CPU when waiting for events - Disk read, network packet arrival, pipe write, signal, etc. • int tsleep(void *ident, int priority, ...); - Switches to another process - ident is arbitrary pointer—e.g., buffer address - priority is priority at which to run when woken up - PCATCH, if ORed into priority, means wake up on signal - Returns 0 if awakened, or ERESTART/EINTR on signal • int wakeup(void *ident); - Awakens all processes sleeping on ident - Restores SPL a time they went to sleep (so fine to sleep at splhigh) Process scheduling • Goal: High throughput - Minimize context switches to avoid wasting CPU, TLB misses, cache misses, even page faults. • Goal: Low latency - People typing at editors want fast response - Network services can be latency-bound, not CPU-bound • BSD time quantum: 1=10 sec (since ∼1980) - Empirically longest tolerable latency - Computers now faster, but job queues also shorter Scheduling algorithms • Round-robin • Priority scheduling • Shortest process next (if you can estimate it) • Fair-Share Schedule (try to be fair at level of users, not processes) Multilevel feeedback queues (BSD) • Every runnable proc. -
Formal Aspects of Mobile Code Security
FORMAL ASPECTS OF MOBILE CODE SECURITY RICHARD DREWS DEAN ADISSERTATION PRESENTED TO THE FACULTY OF PRINCETON UNIVERSITY IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY RECOMMENDED FOR ACCEPTANCE BY THE DEPARTMENT OF COMPUTER SCIENCE JANUARY 1999 c Copyright by Richard Drews Dean, 1998. All Rights Reserved Abstract We believe that formal methods of all kinds are critical to mobile code security, as one route to gaining the assurance level necessary for running potentially hos- tile code on a routine basis. We begin by examining Java, and understanding the weaknesses in its architecture, on both design and implementation levels. Iden- tifying dynamic linking as a key problem, we produce a formal model of linking, and prove desirable properties about our model. This investigation leads to a deep understanding of the underlying problem. Finally, we turn our attention to crypto- graphic hash functions, and their analysis with binary decision diagrams (BDDs). We show that three commonly used hash functions (MD4, MD5, and SHA-1) do not offer ideal strength against second preimages. The ability of a cryptographic hash function to resist the finding of second preimages is critical for its use in digi- tal signature schemes: a second preimage enables the forgery of digital signatures, which would undermine confidence in digitally signed mobile code. Our results show that modern theorem provers and BDD-based reasoning tools are effective for reasoning about some of the key problems facing mobile code security today. iii Acknowledgments My advisor, Andrew Appel, offered sure guidance through what turned out to be an exceptionally smooth journey through graduate school. -
Lecture 7 Network Management and Debugging
SYSTEM ADMINISTRATION MTAT.08.021 LECTURE 7 NETWORK MANAGEMENT AND DEBUGGING Prepared By: Amnir Hadachi and Artjom Lind University of Tartu, Institute of Computer Science [email protected] / [email protected] 1 LECTURE 7: NETWORK MGT AND DEBUGGING OUTLINE 1.Intro 2.Network Troubleshooting 3.Ping 4.SmokePing 5.Trace route 6.Network statistics 7.Inspection of live interface activity 8.Packet sniffers 9.Network management protocols 10.Network mapper 2 1. INTRO 3 LECTURE 7: NETWORK MGT AND DEBUGGING INTRO QUOTE: Networks has tendency to increase the number of interdependencies among machine; therefore, they tend to magnify problems. • Network management tasks: ✴ Fault detection for networks, gateways, and critical servers ✴ Schemes for notifying an administrator of problems ✴ General network monitoring, to balance load and plan expansion ✴ Documentation and visualization of the network ✴ Administration of network devices from a central site 4 LECTURE 7: NETWORK MGT AND DEBUGGING INTRO Network Size 160 120 80 40 Management Procedures 0 AUTOMATION ILLUSTRATION OF NETWORK GROWTH VS MGT PROCEDURES AUTOMATION 5 LECTURE 7: NETWORK MGT AND DEBUGGING INTRO • Network: • Subnets + Routers / switches Time to consider • Automating mgt tasks: • shell scripting source: http://www.eventhelix.com/RealtimeMantra/Networking/ip_routing.htm#.VvjkA2MQhIY • network mgt station 6 2. NETWORK TROUBLES HOOTING 7 LECTURE 7: NETWORK MGT AND DEBUGGING NETWORK TROUBLESHOOTING • Many tools are available for debugging • Debugging: • Low-level (e.g. TCP/IP layer) • high-level (e.g. DNS, NFS, and HTTP) • This section progress: ping trace route GENERAL ESSENTIAL TROUBLESHOOTING netstat TOOLS STRATEGY nmap tcpdump … 8 LECTURE 7: NETWORK MGT AND DEBUGGING NETWORK TROUBLESHOOTING • Before action, principle to consider: ✴ Make one change at a time ✴ Document the situation as it was before you got involved. -
Common Commands Cheat Sheet by Mmorykan Via Cheatography.Com/89673/Cs/20411
Common Commands Cheat Sheet by mmorykan via cheatography.com/89673/cs/20411/ Scripting Scripting (cont) GitHub bash filename - Runs script sleep value - Forces the script to wait value git clone <url > - Clones gitkeeper url Shebang - "# !bi n/b ash " - First line of bash seconds git add <fil ena me> - Adds the file to git script. Tells script what binary to use while [[ condition ]]; do stuff; done git commit - Commits all files to git ./file name - Also runs script if [[ condition ]]; do stuff; fi git push - Pushes all git files to host # - Creates a comment until [[ condition ]]; do stuff; done echo ${varia ble} - Prints variable words=" h ouse dogs telephone dog" - Package / Networking hello_int = 1 - Treats "1 " as a string Declares words array dnf upgrade - Updates system packages Use UPPERC ASE for constant variables for word in ${words} - traverses each dnf install - Installs package element in array Use lowerc ase _wi th_ und ers cores for dnf search - Searches for package for counter in {1..10} - Loops 10 times regular variables dnf remove - Removes package for ((;;)) - Is infinite for loop echo $(( ${hello _int} + 1 )) - Treats hello_int systemctl start - Starts systemd service as an integer and prints 2 break - exits loop body systemctl stop - Stops systemd service mktemp - Creates temporary random file for ((count er=1; counter -le 10; counter ++)) systemctl restart - Restarts systemd service test - Denoted by "[[ condition ]]" tests the - Loops 10 times systemctl reload - Reloads systemd service condition -
Yutaka Oiwa. "Implementation of a Fail-Safe ANSI C Compiler"
Implementation of a Fail-Safe ANSI C Compiler 安全な ANSI C コンパイラの実装手法 Doctoral Dissertation 博士論文 Yutaka Oiwa 大岩 寛 Submitted to Department of Computer Science, Graduate School of Information Science and Technology, The University of Tokyo on December 16, 2004 in partial fulfillment of the requirements for the degree of Doctor of Philosophy Abstract Programs written in the C language often suffer from nasty errors due to dangling pointers and buffer overflow. Such errors in Internet server programs are often ex- ploited by malicious attackers to “crack” an entire system, and this has become a problem affecting society as a whole. The root of these errors is usually corruption of on-memory data structures caused by out-of-bound array accesses. The C lan- guage does not provide any protection against such out-of-bound access, although recent languages such as Java, C#, Lisp and ML provide such protection. Never- theless, the C language itself should not be blamed for this shortcoming—it was designed to provide a replacement for assembly languages (i.e., to provide flexible direct memory access through a light-weight high-level language). In other words, lack of array boundary protection is “by design.” In addition, the C language was designed more than thirty years ago when there was not enough computer power to perform a memory boundary check for every memory access. The real prob- lem is the use of the C language for current casual programming, which does not usually require such direct memory accesses. We cannot realistically discard the C language right away, though, because there are many legacy programs written in the C language and many legacy programmers accustomed to the C language and its programming style. -
Bringing GNU Emacs to Native Code
Bringing GNU Emacs to Native Code Andrea Corallo Luca Nassi Nicola Manca [email protected] [email protected] [email protected] CNR-SPIN Genoa, Italy ABSTRACT such a long-standing project. Although this makes it didactic, some Emacs Lisp (Elisp) is the Lisp dialect used by the Emacs text editor limitations prevent the current implementation of Emacs Lisp to family. GNU Emacs can currently execute Elisp code either inter- be appealing for broader use. In this context, performance issues preted or byte-interpreted after it has been compiled to byte-code. represent the main bottleneck, which can be broken down in three In this work we discuss the implementation of an optimizing com- main sub-problems: piler approach for Elisp targeting native code. The native compiler • lack of true multi-threading support, employs the byte-compiler’s internal representation as input and • garbage collection speed, exploits libgccjit to achieve code generation using the GNU Com- • code execution speed. piler Collection (GCC) infrastructure. Generated executables are From now on we will focus on the last of these issues, which con- stored as binary files and can be loaded and unloaded dynamically. stitutes the topic of this work. Most of the functionality of the compiler is written in Elisp itself, The current implementation traditionally approaches the prob- including several optimization passes, paired with a C back-end lem of code execution speed in two ways: to interface with the GNU Emacs core and libgccjit. Though still a work in progress, our implementation is able to bootstrap a func- • Implementing a large number of performance-sensitive prim- tional Emacs and compile all lexically scoped Elisp files, including itive functions (also known as subr) in C. -
Unix/Linux Command Reference
Unix/Linux Command Reference .com File Commands System Info ls – directory listing date – show the current date and time ls -al – formatted listing with hidden files cal – show this month's calendar cd dir - change directory to dir uptime – show current uptime cd – change to home w – display who is online pwd – show current directory whoami – who you are logged in as mkdir dir – create a directory dir finger user – display information about user rm file – delete file uname -a – show kernel information rm -r dir – delete directory dir cat /proc/cpuinfo – cpu information rm -f file – force remove file cat /proc/meminfo – memory information rm -rf dir – force remove directory dir * man command – show the manual for command cp file1 file2 – copy file1 to file2 df – show disk usage cp -r dir1 dir2 – copy dir1 to dir2; create dir2 if it du – show directory space usage doesn't exist free – show memory and swap usage mv file1 file2 – rename or move file1 to file2 whereis app – show possible locations of app if file2 is an existing directory, moves file1 into which app – show which app will be run by default directory file2 ln -s file link – create symbolic link link to file Compression touch file – create or update file tar cf file.tar files – create a tar named cat > file – places standard input into file file.tar containing files more file – output the contents of file tar xf file.tar – extract the files from file.tar head file – output the first 10 lines of file tar czf file.tar.gz files – create a tar with tail file – output the last 10 lines