Thesis (Ph. D.)--Brigham Young University. Dept. of Instructional Psychology & Technology, 2003. / Includes bibliographical references (p. 205-210).

No description available.

Call number: LD2668 .T4 1985 R42 / Master of Science

Time-shared, virtual memory systems are very complex and changes in their performance may be caused by many factors - by variations in the workload as well as changes in system configuration. The evaluation of these systems can thus best be carried out by linking results obtained from a planned programme of measurements, taken on the system, to some model of it. Such a programme of measurements is best carried out under conditions in which all the parameters likely to affect the system's performance are reproducible, and under the control of the experimenter. In order that this be possible the workload used must be simulated and presented to the target system through some form of automatic workload driver. A case study of such a methodology is presented in which the system (in this case the Edinburgh Multi-Access System) is monitored during a controlled experiment (designed and analysed using standard techniques in common use in many other branches of experimental science) and the results so obtained used to calibrate and validate a simple simulation model of the system. This model is then used in further investigation of the effect of certain system parameters upon the system performance. The factors covered by this exercise include the effect of varying: main memory size, process loading algorithm and secondary memory characteristics.

published_or_final_version / Computer Science / Master / Master of Philosophy

The frequency spectrum allocated to cellular mobile telephone systems is very limited. Efficient channel assignment schemes can significantly increase the utilization of the available frequency channels. Virtually Fixed Channel Assignment (VFCA) is a dynamic channel assignment method. The idea behind it is simple: each cell is allocated a set of nominal channels. A call request generated in a cell is assigned a nominal channel if one is available. Otherwise, a channel from an adjacent cell is borrowed to serve this call as long as frequency interference constraints are satisfied. VFCA is a promising method because (i) it is efficient in channel assignment, and (ii) it is relatively easy to implement compared to other dynamic channel assignment methods. VFCA has been analyzed based primarily on simulation studies in the past twenty years. In this thesis, we focus our study on development of new channel borrowing strategies and analytical models for VFCA. The contribution of this work is summarized as follows. (1) Development of an queuing model for performance analysis of VFCA. This model may also be used to conduct sensitivity analysis on some system parameters when VFCA is used. (2) Proposed a new channel reservation scheme for handoffs. (In a cellular system, when a call using a channel crosses a cell boundary, it needs to be handed off to a new channel in the new cell. This is called a handoff.) An optimization model for this channel reservation scheme is developed. (3) Applied the fluid-flow approach to modeling an integrated mobile cellular system that uses VFCA to estimate the distribution of data queue length in a cell of the system. These results are useful in the design, performance analysis and optimization of VFCA schemes.

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Thesis (M.A.)--York University, 2005. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 63-68). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11830

Pierre Dersin, Alexander H. Levis. / Bibliography: leaves [5]-[6]. / "January 1984." Paper to be presented at the 9th IFAC World Congree, Budapest, Hungary, July 2-6, 1984. / AC01-77-ET29033

Thesis (MPhil)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Information System Success Evaluation has been a concept of interest to many organizations for decades now. The main motivation for this activity is usually from the financial view of things, that is, the main interest of an organization carrying out IS success evaluation is mainly to find out whether investing in such a system was a good business decision. This question is often answered by the realization of the direct and indirect benefits realized by deployment of using such a system. Like many organizations the government of Botswana has invested millions of Pula’s in the past number of years in acquiring and implementing different Information Systems in the various Ministries and Departments. One such system is the Vehicle Registration and Licensing System, which was deployed by the Department of Roads Transport and Safety of the Ministry of Works, Transport and Communication. After the VRLS implementation there has not been any formal scientific research or investigation conducted to find out the success of this Information System, especially with regards to the stakeholders who use this system for their daily jobs. This study therefore engaged in a task, which evaluated the success of the Vehicle Registration and Licensing System and answered the question of how effective the system is from the user’s point of view. A well-known Information System success evaluation model, known as the Delone and McLean IS evaluation model, was applied to test the hypothesis of this research. A structured questionnaire was used to collect the research data. The results were analyzed using a common research tool, the SPSS, including cross tabulation and chisquare tests. The findings of this study will further enrich the IS success evaluation Body of Knowledge on the key factors which can contribute to a successful or unsuccessful Information System acquisition investment. Furthermore, the researchers who will further look into this subject may find these findings very useful and also stimulating to do further research on this subject to unveil further evidence of the ingredients of an effective Information System investment which has been accepted by and accredited by its users. / AFRIKAANSE OPSOMMING: Inligtingstelselsuksesevaluering is ‘n konsep wat baie organisasies nou al vir dekades interesseer. Die motivering hiervoor is hoofsaaklik geleë in finansiële redes. Organisasies wil hiermee vasstel of dit ‘n goeie besigheidsbesluit was. Hierdie vraag word dan dikwels beantwoord deur die verkryging van direkte en indirekte voordele deur gebruik te maak van so ‘n stelsel. Soos baie organisasies het die regering van Botswana miljoene pula belê in die implementering van inligtingstelsels in verskeie staatsdepartemente. Die Voertuigregistrasie en Lisensiestelsel is ‘n voorbeeld hiervan wat deur die Departement van Padvervoer en -Veiligheid van die Ministerie van Werke, Vervoer en Kommunikasie ontplooi is. Geen formele wetenskaplike navorsing is geloods na afloop van die implementering van die stelsel nie, veral nie sedert die gebruik deur motoriste nie. Hierdie studie poog juis om die effektiwiteit van die stelsel te meet, veral vanuit die verbruiker se perspektief. Die Delone en Mclean Inligtingstelselevalueringsmodel word gebruik om die hipotese van die navorsing te toets. ‘n Gestruktureerde vraelys is opgestel om data te versamel. Die SPSS as ‘n algemene navorsingsinstrument is gebruik vir analise, asook vir kruistabulasie en chikwadraattoetse. Die bevindinge van die studie sal die korpus van kennis van inligtingstelselsuksesevaluering verryk ten opsigte van die sleutelfaktore wat kan bydra tot die sukses of nie-sukses van inligtingstelselimplementering. Verdere studie in hierdie betrokke gebied word deur die navorsing gestimuleer, om veral die effektiwiteit van Inligtingstelselbeleggings te bepaal.