176,558 research outputs found

    Electronics and control technology

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    Until recently, there was no requirement to learn electronics and control technology in the New Zealand school curriculum. Apart from isolated pockets of teaching based on the enthusiasm of individual teachers, there is very little direct learning of electronics in New Zealand primary or secondary schools. The learning of electronics is located in tertiary vocational training programmes. Thus, few school students learn about electronics and few school teachers have experience in teaching it. Lack of experience with electronics (other than using its products) has contributed to a commonly held view of electronics as out of the control and intellectual grasp of the average person; the domain of the engineer, programmer and enthusiast with his or her special aptitude. This need not be true, but teachers' and parents' lack of experience with electronics is in danger of denying young learners access to the mainstream of modern technology

    Body language, security and e-commerce

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    Security is becoming an increasingly more important concern both at the desktop level and at the network level. This article discusses several approaches to authenticating individuals through the use of biometric devices. While libraries might not implement such devices, they may appear in the near future of desktop computing, particularly for access to institutional computers or for access to sensitive information. Other approaches to computer security focus on protecting the contents of electronic transmissions and verification of individual users. After a brief overview of encryption technologies, the article examines public-key cryptography which is getting a lot of attention in the business world in what is called public key infrastructure. It also examines other efforts, such as IBM’s Cryptolope, the Secure Sockets Layer of Web browsers, and Digital Certificates and Signatures. Secure electronic transmissions are an important condition for conducting business on the Net. These business transactions are not limited to purchase orders, invoices, and contracts. This could become an important tool for information vendors and publishers to control access to the electronic resources they license. As license negotiators and contract administrators, librarians need to be aware of what is happening in these new technologies and the impact that will have on their operations

    System for simultaneously loading program to master computer memory devices and corresponding slave computer memory devices

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    A bus programmable slave module card for use in a computer control system is disclosed which comprises a master computer and one or more slave computer modules interfacing by means of a bus. Each slave module includes its own microprocessor, memory, and control program for acting as a single loop controller. The slave card includes a plurality of memory means (S1, S2...) corresponding to a like plurality of memory devices (C1, C2...) in the master computer, for each slave memory means its own communication lines connectable through the bus with memory communication lines of an associated memory device in the master computer, and a one-way electronic door which is switchable to either a closed condition or a one-way open condition. With the door closed, communication lines between master computer memory (C1, C2...) and slave memory (S1, S2...) are blocked. In the one-way open condition invention, the memory communication lines or each slave memory means (S1, S2...) connect with the memory communication lines of its associated memory device (C1, C2...) in the master computer, and the memory devices (C1, C2...) of the master computer and slave card are electrically parallel such that information seen by the master's memory is also seen by the slave's memory. The slave card is also connectable to a switch for electronically removing the slave microprocessor from the system. With the master computer and the slave card in programming mode relationship, and the slave microprocessor electronically removed from the system, loading a program in the memory devices (C1, C2...) of the master accomplishes a parallel loading into the memory devices (S1, S2...) of the slave

    Data Acquisition and Control System of Hydroelectric Power Plant Using Internet Techniques

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    Vodní energie se nyní stala nejlepším zdrojem elektrické energie na zemi. Vyrábí se pomocí energie poskytované pohybem nebo pádem vody. Historie dokazuje, že náklady na tuto elektrickou energii zůstávají konstantní v průběhu celého roku. Vzhledem k mnoha výhodám, většina zemí nyní využívá vodní energie jako hlavní zdroj pro výrobu elektrické energie.Nejdůležitější výhodou je, že vodní energie je zelená energie, což znamená, že žádné vzdušné nebo vodní znečišťující látky nejsou vyráběny, také žádné skleníkové plyny jako oxid uhličitý nejsou vyráběny, což činí tento zdroj energie šetrný k životnímu prostředí. A tak brání nebezpečí globálního oteplování. Použití internetové techniky k ovladání několika vodních elektráren má velmi významné výhody, jako snížení provozních nákladů a flexibilitu uspokojení změny poptávky po energii na straně spotřeby. Také velmi efektivně čelí velkým narušením elektrické sítě, jako je například přidání nebo odebrání velké zátěže, a poruch. Na druhou stranu, systém získávání dat poskytuje velmi užitečné informace pro typické i vědecké analýzy, jako jsou ekonomické náklady, predikce poruchy systémů, predikce poptávky, plány údržby, systémů pro podporu rozhodování a mnoho dalších výhod. Tato práce popisuje všeobecný model, který může být použit k simulaci pro sběr dat a kontrolní systémy pro vodní elektrárny v prostředí Matlab / Simulink a TrueTime Simulink knihovnu. Uvažovaná elektrárna sestává z vodní turbíny připojené k synchronnímu generátoru s budicí soustavou, generátor je připojen k veřejné elektrické síti. Simulací vodní turbíny a synchronního generátoru lze provést pomocí různých simulačních nástrojů. V této práci je upřednostňován SIMULINK / MATLAB před jinými nástroji k modelování dynamik vodní turbíny a synchronního stroje. Program s prostředím MATLAB SIMULINK využívá k řešení schematický model vodní elektrárny sestavený ze základních funkčních bloků. Tento přístup je pedagogicky lepší než komplikované kódy jiných softwarových programů. Knihovna programu Simulink obsahuje funkční bloky, které mohou být spojovány, upravovány a modelovány. K vytvoření a simulování internetových a Real Time systémů je možné použít bud‘ knihovnu simulinku Real-Time nebo TRUETIME, v práci byla použita knihovna TRUETIME.Hydropower has now become the best source of electricity on earth. It is produced due to the energy provided by moving or falling water. History proves that the cost of this electricity remains constant over the year. Because of the many advantages, most of the countries now have hydropower as the source of major electricity producer. The most important advantage of hydropower is that it is green energy, which mean that no air or water pollutants are produced, also no greenhouse gases like carbon dioxide are produced which makes this source of energy environment-friendly. It prevents us from the danger of global warming. Using internet techniques to control several hydroelectric plants has very important advantages, as reducing operating costs and the flexibility of meeting changes of energy demand occurred in consumption side. Also it is very effective to confront large disturbances of electrical grid, such as adding or removing large loads, and faults. In the other hand, data acquisition systems provides very useful information for both typical and scientific analysis, such as economical costs reducing, fault prediction systems, demand prediction, maintenance schedules, decision support systems and many other benefits. This thesis describes a generalized model which can be used to simulate a data acquisition and control system of hydroelectric power plant using MATLAB/SIMULINK and TrueTime simulink library. The plant considered consists of hydro turbine connected to synchronous generator with excitation system, and the generator is connected to public grid. Simulation of hydro turbine and synchronous generator can be done using various simulation tools, In this work, SIMULINK/MATLAB is favored over other tools in modeling the dynamics of a hydro turbine and synchronous machine. The SIMULINK program in MATLAB is used to obtain a schematic model of the hydro plant by means of basic function blocks. This approach is pedagogically better than using a compilation of program code as in other software programs .The library of SIMULINK software programs includes function blocks which can be linked and edited to model. Either Simulink Real-Time library or TrueTime library can be used to build and simulate internet and real time systems, in this thesis the TrueTime library was used.

    Beginner's Guide for Cybercrime Investigators

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    In the real world there are people who enter the homes and steal everything they find valuable. In the virtual world there are individuals who penetrate computer systems and "steal" all your valuable data. Just as in the real world, there are uninvited guests and people feel happy when they steal or destroy someone else's property, the computer world could not be deprived of this unfortunate phenomenon. It is truly detestable the perfidy of these attacks. For if it can be observed immediately the apparent lack of box jewelry, penetration of an accounting server can be detected after a few months when all clients have given up the company services because of the stolen data came to competition and have helped it to make best deals. Cybercrime is a phenomenon of our time, often reflected in the media. Forensic investigation of computer systems has a number of features that differentiate it fundamentally from other types of investigations. The computer itself is the main source of information for the investigator. CONTENTS: Computing systems and storage media - Computing devices - - Peripheral devices - - External drives for media storage - Typology of data stored on specific supports – File systems - - Program that allows working with ” inactive” space - Information that can be obtained from the computing system environment Computer networks - Copper wire in computer networks - Optical fibers - Wireless LAN - Internet and Intranet Software and services - Client/server architecture - Protocols and Standards - Internet Services - - e-Mail - - - Spam - - HTTP - - Web address - URL - - Web browsers - - - Browser cookies - - Working with web pages - - - Choosing your favorite web pages - - - Keeping track of visited web pages - - - Saving web pages - - Proxy servers - - Privacy on the Internet - FTP - Instant Messaging - Peer-to-peer networks Vulnerabilities - The first attacks on the Internet - Cybercrime - - Typologies of cyber attackers - - - Classification of cyber attackers according to their skills and objectives - Classification of risks and incidents in cyberworld - - Classification as a list of terms - - List of categories - - Categories of results - - Empirical lists - Events, attacks and incidents - Online security events, actions, and targets - - Actions - - Targets - Attacks - - Tools - - Vulnerabilities - - Unauthorized results Cybercrime laws - The concept of "cybercrime" Investigations - Computer forensic investigations - Digital evidence - Digital sampling during investigations - The suspect - Witnesses in cybercrime - Transporting of samples in laboratory - Analysis of samples - Preparing team members - Computer tools Convention on Cybercrime - Preamble - Chapter I – Use of terms - Chapter II – Measures to be taken at the national level - - Section 1 – Substantive criminal law - - - Title 1 – Offences against the confidentiality, integrity and availability of computer data and systems - - - Title 2 – Computer-related offences - - - Title 3 – Content-related offences - - - Title 4 – Offences related to infringements of copyright and related rights - - - Title 5 – Ancillary liability and sanctions - - Section 2 – Procedural law - - - Title 1 – Common provisions - - - Title 2 – Expedited preservation of stored computer data - - - Title 3 – Production order - - - Title 4 – Search and seizure of stored computer data - - - Title 5 – Real-time collection of computer data - - Section 3 – Jurisdiction - Chapter III – International co-operation - - Section 1 – General principles - - - Title 1 – General principles relating to international co-operation - - - Title 2 – Principles relating to extradition - - - Title 3 – General principles relating to mutual assistance - - - Title 4 – Procedures pertaining to mutual assistance requests in the absence of applicable international agreements - - Section 2 – Specific provisions - - - Title 1 – Mutual assistance regarding provisional measures - - - Title 2 – Mutual assistance regarding investigative powers - - - Title 3 – 24/7 Network - Chapter IV – Final provisions Recommendation No. R (95) 13 - Appendix to Recommendation No. R (95) 13 - - I. Search and seizure - - II. Technical surveillance - - III. Obligations to co-operate with the investigating authorities - - IV. Electronic evidence - - V. Use of encryption - - VI. Research, statistics and training - - VII. International co-operation Rules for obtaining digital evidence by police officers Standards in the field of digital forensics Principles in digital evidence Procedures model for the forensic examination - Hard disk examination Code of Ethics Sources and references About - Nicolae Sfetcu - - By the same author - - Contact Publishing House - MultiMedia Publishin

    Real-time simulation clock

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    The invention is a clock for synchronizing operations within a high-speed, distributed data processing network. The clock is actually a distributed system comprising a central clock and multiple site clock interface units (SCIUs) which are connected by means of a fiber optic star network and which operate under control of separate clock software. The presently preferred embodiment is a part of the flight simulation system now in current use at the NASA Langley Research Center

    Focal Spot, Fall/Winter 1986

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    https://digitalcommons.wustl.edu/focal_spot_archives/1044/thumbnail.jp

    Cyber Insurance, Data Security, and Blockchain in the Wake of the Equifax Breach

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    Deep Space Network information system architecture study

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    The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control
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