In order to reduce the price for, and improve the performance of automatic control systems for magnetization of synchronus generators, the possibilities of using a PC based software PLC system, Programmable Logic Controller, has been investigated. The result is a system based on the CoDeSys software PLC with runtime environment from 3S-Software, communicating with external units via Modbus fieldbus. System price is reduced from ?5000 to ?2000 and system processing speed is reduced from 10 ms for a Siemens S7 PLC to 4 ms with the CoDeSys PLC system though unsolved problems with runtime seizure caused by improper settings in the PC BIOS..

Human-computer interaction is central for computer assisted development. The aim was to investigate the user experience of a new (U2) compared to an old (U1) computer system, within a cognitive psychology frame of reference. Six subjects, frequently using the system, participated in the study. It was shown that the new (U2) compared to the old system (U1) enhanced and supported more the users? system related procedures/tasks.

Attacker och intrång på webbservrar är idag vanligt förekommande. Webben gör det lätt för hackare, knäckare och andra inkräktare att hitta sårbara servrar, och det finns gott om tips att hämta för den som vill lära sig hur man gör intrång. Det finns ett flertal olika intrångsmetoder som utnyttjar olika typer av svagheter i datorsystemen. Denna uppsats inriktar sig på svagheter i webbplatsernas serverskriptsystem, dess skriptkod och konfiguration. Syftet är att undersöka huruvida intrång kan göras med endast en webbläsare via webbplatsens offentliga webbsidor. Genom att kombinera tre olika metoder - litteraturundersökning, en enkät och ett experiment - undersöker uppsatsen hur serverskriptintrång fungerar.

This report documents the process of designing a laboratory exercise in Fourier analysis at Vetenskapens Hus (House of Science) in Stockholm. The lab is designed for high school students studying science or technical education. It focuses on the physicalunderstanding and mathematical description of sound, in particular music. A model of such a lab is presented in this work; containing a review of the mathematical theory, summary of educational research in the field, descriptions of the design process and of the investigativework that led to the final result. The designed material for the lab includes developed computer programs, visit leader tutorial and description for teachers. .

The purpose with my degree project is to investigate the use of computers within the daily activity in three preschools and one preschool class. I have designed a survey that I distributed to the staff. The purpose of my work is to investigate how a number of preschool teachers and children in a few preschools and one preschool class in a medium-sized Swedish town are using the computer in their activities.My study shows that the computer is frequently used, both of the children and teachers, but also together. The children in my study are using the computer to play games, listen to music, and go into the websitewww.youtube.com, but also in order to write and count.  The teachers primarily use the computer to document, check their e-mail and listen to music.

The main purpose of this study is to investigate the unintentional learning that happens during the use of computer games. With the use of interviews with students in the ages 13-15 who all have played the game series Assassin?s Creed, and then compared them with students who does not play the game, we have been able to identify that some learning is taking place, but that the student?s attitude towards the subject, and their maturity, also is vital for the learning. Even tough, the students who didn?t really enjoy history as a subject showed better knowledge after playing the game, than the students who hadn?t played at all, which indicates that computer games can be a good source for learning.

Med denna uppsats vill vi (författarna) samla ihop 5 år av tankar, teorier och erfarenheter kring systemutveckling och lärande. Uppsatsen presenterar 8 projekt som är genomförda i Blekinge mellan 1995-1999. Med utgångspunkt i projekten behandlas en utvecklingsprocess för IT-system som är baserad på kreativitet och lärande miljöer. Särskilt lyfter uupsatsen fram behovet av att förändra processen för att möta slutanvändare av program och tjänster..

VD:n för spelindustrins intresseorganisation (Interactive Digital Software Association) förutspår i den årliga State of the Industry rapporten för åren 2000 ? 2001, att spelindustrin snart kan nå 70 procent av världens hushåll, vilket gör spelmaskinen, näst intill, lika vanlig som videon. I denna dag börjar många spelutbildningar växa fram i hela landet, så som i Karlshamn, Visby och Kramfors. Trots denna tillväxt finns det nästan ingen akademisk forskning i ämnet speldesign. Detta gör att hjulet i många fall tvingas återuppfinnas om och om igen. I detta kandidatarbete är huvuddiskussionen hur man designar ett spel innehållande både spelfrihet och en färdig berättelse, vilket är en konflikt i sig. Vi försöker identifiera kärnan av ett spels design genom att samarbeta med både användare och designers av digital underhållning och sätta detta i relation till de studier av spel vi gjort.

The Mission at ÅF Industry in Norrkoping was about optimizing bulk data handling while importing process tag types from their construction database into the Process Controlled System of type Siemens PCS7.I found three different methods to solve the task. Two of them were using different software from Siemens under the premise that the report from the database was corrected as needed. The third variant was manually creating the circuits. All methods worked out fine but there were times when one was better than another.To solve this task I had access to all software presented in chapter 2 ?Programvara? (=Software).

Most often when developing a new system there is a need get a functioning testtool up and running. Including time, cost and resources the solution isn?t always obvious, developing your own or buy one ?of the shelf?. The purpose of this thesis is to study how a general testtool for executing functional tests should be designed to be reusable, be based on recognized knowledge and be able to fast and simple be customized for different types of systems. Key functions from the litterature is presented and used in the design of a testtool prototype.

The development of software was considered until the beginning of the 1990th as a cathedral like product development in closed companies. This way of development changed in the last decade. Open source software (OSS) development challenged this consideration significantly. OSS is produced in co-operation by skilled people, distributed and used by many moral agents. The result, the software itself, can be studied and modified.

The emphasize of this study is to evaluate security issues for home users having a personal computer connected to the Internet. It focus on the usage of advantages and disadvantages when using a firewall while connected to the Internet. The hypothesis is that it gives a better protection to install and use a firewall compared not to do so, due to security flaws in the operating system. The prediction was tested on a home user's personal computer. The testwork was divided into two major tests, each of them performed with, respectively without, a firewall. These major tests were divided into five smaller semi­ tests. The first semi­test without a firewall suffered from a virus or worm attack resulting in loss of data and log files.

Dokumentet är ett resultat av studier gjorda under kursen Kandidatarbete I Datavetenskap. Arbetet utforskade, genom fallstudie, två egenskaper av distribuerade informationssystem och relation mellan dessa: säkerhet och prestanda. Målet med fallstudien har varit att belysa nackdelen med användning av Secure Socker Layer (SSL) dvs. dess effekt på hastigheten och fördelen med SSL, dvs. SSL:s roll i informationssäkerhetsarbetet. Arbetet visar hur prestanda i ett tillämpad distribuerat informationssystem kan påverkas av en SSL tillämpning.

This report is a part of the process of enhanced cooperation between fire rescue services in the region of North West Scania. The aim of the report is to study and analyze how the fire rescue service should be structured, in terms of rescue units and personnel, if no account is to be taking to the current organization. Two types of accident are considered in the report, traffic accidents and building fires. These are more affected by decreased response time than other accidents. Several suggested organizations are presented and they are evaluated with the computer program REP.

E-commerce is a conception who many are taking about nowadays. E-commerce is associate with computer based business and it?s a new way to do business on. Users and system connect up to each other for effective mediate and transfer information. Within e-commerce there?s a lot of ways to do business on and it can for example be between a business and a another business (B2B) or between business and consumer (B2C).In this degree report have I reached if small business will invest on e-commerce and if they will, how.