Major Trends in Operating Systems Development

Operating systems have changed in nature in response to demands of users, and in response to advances in hardware and software technology. The purpose of this paper is to trace the development of major themes in operating system design from their beginnings through the present. This is not an exhaustive history of operating systems, but instead is intended to give the reader the flavor of the dif ferent periods in operating systems\u27 development. To this end, the paper will be organized by topic in approximate order of development. Each chapter will start with an introduction to the factors behind the rise of the period. This will be fol lowed by a survey of the state-of-the-art systems, and the conditions influencing them. The chapters close with a summation of the significant hardware and software contributions from the period

Mechanical Translation

Contains research objectives and reports on two research objectives.National Science Foundation (Grant GN-244

Neurology

Contains reports on nineteen research projects.United States Public Health Service (B-3055-3, B-3090-3, 38101-22)United States Navy, Office of Naval Research (Contract Nonr-1841(70))Unites States Air Force (AF33(616)-7588, AFAOSR 155-63)United States Army Chemical Corps (DA-18-108-405-Cml-942)National Institutes of Health (Grant MH-04734-03)National Aeronautics and Space Administration (Grant NsG-496

Early computing and data processing in Malta

Malta has been a heavy user of computers only since the 1980s, following the availability of the personal computer. Before that date, the diffusion of computers in Malta was slow. This paper describes the supply and application of computers from the late 1960s until the early 1980s. The state of computing and the slow take-up of computers is analysed and explained. The paper concludes with an explanation for 'fake off' in the 1980s.peer-reviewe

Resolving the Password Security Purgatory in the Contexts of Technology, Security and Human Factors

YesPasswords are the most popular and constitute the first line of defence in computer-based security systems; despite the existence of more attack-resistant authentication schemes. In order to enhance password security, it is imperative to strike a balance between having enough rules to maintain good security and not having too many rules that would compel users to take evasive actions which would, in turn, compromise security. It is noted that the human factor is the most critical element in the security system for at least three possible reasons; it is the weakest link, the only factor that exercises initiatives, as well as the factor that transcends all the other elements of the entire system. This illustrates the significance of social engineering in security designs, and the fact that security is indeed a function of both technology and human factors; bearing in mind the fact that there can be no technical hacking in vacuum. This paper examines the current divergence among security engineers as regards the rules governing best practices in the use of passwords: should they be written down or memorized; changed frequently or remain permanent? It also attempts to elucidate the facts surrounding some of the myths associated with computer security. This paper posits that destitution of requisite balance between the factors of technology and factors of humanity is responsible for the purgatory posture of password security related problems. It is thus recommended that, in the handling of password security issues, human factors should be given priority over technological factors. The paper proposes the use of the (k, n)-Threshold Scheme, such as the Shamir’s secret-sharing scheme, to enhance the security of the password repository. This presupposes an inclination towards writing down the password: after all, Diamond, Platinum, Gold and Silver are not memorised; they are stored.Petroleum Technology Development Fun

On Intelligent Mitigation of Process Starvation In Multilevel Feedback Queue Scheduling

CPU time-share process schedulers for computer operating systems have existed since Corbato published his paper on the Compatible Time Sharing System in 1962 [8]. With this new type of scheduler came the need to effectively divide CPU time between N processes, where N could be 2 or more processes. Modern time-sharing process schedulers which have been developed in the decades since have been designed to favor shorter, interactive processes over long-running processes, especially when incoming demand for CPU time exceeds supply and process starvation is inevitable. These schedulers, including Linux CFS, FreeBSD Ule, and the Solaris Fair Share Scheduler, are all effective at favoring interactive processes under starvation conditions. Sometimes it’s not desirable that long-running processes be sacrificed altogether, but none of these schedulers have safeguards under starvation conditions. This thesis revisits and extends the research conducted in [13], in which it was demonstrated that starvation of long-running processes could be safely and effectively mitigated without adversely affecting the performance of shorter, interactive processes. The questions this thesis will answer are: Can MLFQ-NS, proposed in [13], be compared to other modern process schedulers? Can MLFQ-NS be improved? To answer the first question, a scheduler must be found which is similar enough to MFLQ for a direct comparison. This will require a survey of current schedulers. To answer the second question, the research conducted in [13] must be duplicated MLFQ-NS to ascertain the following: How much diverted time is actually used? Why does MLFQ-NS become ineffective past a certain system-load threshold, i.e. stop real- locating time to long-runnning processes? In this research, the original work was duplicated in simulations to validate previous re- sults, and determine why MLFQ-NS became ineffective after incoming CPU time demand exceeds a threshold. Research was conducted in order to determine if starvation mitigation in MLFQ-NS could be compared to other process schedulers used in production, with the conclusion that recent emphasis on priority scheduling and heurstic interactivity determination makes such a comparison impossible. Research then continued with simulations in which MLFQ-NS was given different run- time arguments than original simulations. Investigations into those results led to an algorithmic modification to MLFQ-NS called MLFQ-IM and analysis of simulations of MLFQ-IM. Conclu- sions about the effectiveness of MLFQ-IM will be explored. Finally, ideas for future research are offered

Plasma physics modeling and the Cray-2 multiprocessor

The importance of computer modeling in the magnetic fusion energy research program is discussed. The need for the most advanced supercomputers is described. To meet the demand for more powerful scientific computers to solve larger and more complicated problems, the computer industry is developing multiprocessors. The role of the Cray-2 in plasma physics modeling is discussed with some examples. 28 refs., 2 figs., 1 tab