evaluation of operating system wikipedia

... been pointed out (in Chapter 1) that file systems are not considered part of the kernel. File systems are certainly part of the operating system but not part of the kernel. They are considered privileged ... in operating systems research these days. Most “new” systems look like Unix or Windows. Pike makes the point that the domination of these systems serves to reduce the level of innovation in operating ... proof of the correctness of the model for semaphores. The second kernel is of approximately the complexity of kernels such as those built by Digital Equipment for the excellent operating systems...

Ngày tải lên: 23/07/2014, 23:20

... N pgallocstart =0 The value of 0 is completely arbitrary, as is now explained. Some systems map a virtual copy of the operating system onto the vir- tual address space of each user space (and some ... determine a number of properties of CCS and CSP processes, including observational equivalence and bisimilarity. The propositions concerning equivalence of the various versions of the subsystem were ... between the component processes of the subsystem, not in the specification of the components. The processes to be modelled do not have properties suggestive of the use of the π-calculus (e.g., mobility),...

Ngày tải lên: 23/07/2014, 23:20

... comprising the system- call library all send and receive messages. Therefore, the rest of the proof must be in terms of the properties of the message-passing subsystem. The message-passing subsystem is ... of sharedpages(p)(sg), for some p and sg. Proof. Similar to the previous proof. ✷ Proposition 134. IsLockedPage iff lpno? is a locked page; that is, iff lpno? is an element of lockedpages. Proof. ... being “in core”, hence the name of the variable, incore.Thepagecount counts the number of pages in each segment of each process. There is an a priori limit to the number of pages in a segment and pagecount...

Ngày tải lên: 23/07/2014, 23:20

... message contains the identifier of the sending process. It also contains two natural numbers (elements of N). They denote the size of the data area and the size of the stack area that are, respectively, ... prove some fairly general properties of the message-passing system. Proposition 112. The message-passing mechanism is synchronous. Proof. By the predicates of SendMessage and RcvMessage. If the ... bound to the value of currentp by sched.CurrentProcess. ✷ Proposition 119. The receiver of a message is always the current process. Proof. By reasoning similar to the first paragraph of the previous...

Ngày tải lên: 23/07/2014, 23:20

... most significant aspect of this chapter’s model is that it acts as an existence proof. It is possible to define a formal model of an operating system kernel and to prove some of its properties. In ... of the current kernel. 5.2 Requirements The requirement is to model an operating system kernel that is based upon the exchange of messages between processes. The kernel should be an example of ... end of P  than P. 3. If the new value of p r is the same as the old one, one of the two previous conditions will hold. Proof. By Proposition 21. The interesting case is case 3, whose proof follows from...

Ngày tải lên: 23/07/2014, 23:20

... to determine all the children of a parent process. 4.8 General Results This final section contains the proof of a number of propositions that deal with properties of the kernel. The propositions ... an idea of some of the other things that might need to be handled during termination). If a process is on disk when it is terminated (say, because of system ter- mination or because of some error ... enabling it to be represented within the system. As part of this, a test (proctab.CanGenPId)ismadeastowhether the system has reached its maximum number of processes. The schema is com- plicated...

Ngày tải lên: 23/07/2014, 23:20

... descendant of the ancestor of the process just blocked. Proof. This requires the proof of the following lemma. Lemma 16. For any process, p, BlockProcessChildren implies that there are no children of ... closure of the childof relation; the complete set of descendants of a given process are represented by childof + (|{p?}|) for any process identifier p?. In BlockProcessChildren, ps is the set of descendants ... p, BlockProcessChildren ⇒ (∀ p 1 : APREF | childof (p 1 , p) ã p ran userqueue ) Proof. The predicate of BlockProcessChildren contains an instance of MakeUnready inside the scope of the universal quantifier. The...

Ngày tải lên: 23/07/2014, 23:20

Ngày tải lên: 23/07/2014, 23:20

Ngày tải lên: 23/07/2014, 23:20

Ngày tải lên: 23/07/2014, 23:20

Ngày tải lên: 11/08/2014, 16:22

... last 20 years operating systems and their environments have undergone dramatic expansion in size, scope and complexity. The Alto operating system [22], a workstation operating system of the early ... Proceedings of the 11th Operating Systems Principles, November, 1987 Abstract Mach is a multiprocessor operating system being implemented at Carnegie-Mellon University. An important component of the ... Schwans, K., and Vegdahl, S. StarOS, a Multiprocessor Operating System for the Support of Task Forces. In Proceedings of the 7th Symposium on Operating System Principles, pages 117-129. ACM, December,...

Ngày tải lên: 12/09/2012, 15:05

... Evaluation is implemented in 4 phases of investment process: Inception evaluation; Midterm evaluation; Completion evaluation; Impact evaluation or after project evaluation. Monitoring and Evaluation ... the system at the same point of time. - Ability of integrating into email system to destroy virus - Capacity of files, database and Operation System scan - Ability of integrating into Proxy system ... lack of good operation of monitoring and evaluation (M&E). In addition to that, one of the most important factors affecting effectiveness of M&E is the support of Information System...

Ngày tải lên: 18/04/2013, 16:01

... aspects of the various elements of the system [2].In general, the system is of two types (depending on the structure of the system) , a simple structure system and a complex structure system. ... subset of any given set of components which can cause system failure is known as a minimal cut set. A minimal cut set is a set of system components which, when failed, cause failure of the system ... Sulaimani-Erbil Electrical Power System Reliability Evaluation Fig.8 shows the single line diagram of the 132 kV systems for Sulaimani-Erbil electrical power system. For the purpose of reliability assessment,...

Ngày tải lên: 03/01/2014, 19:39

... chal- lenge is the evaluation: manual evaluation is a difficult, time-consuming process and not ap- plicable within efficient development of sys- tems. Automatic evaluation requires a cor- pus of questions ... the majority of cases (83% of the questions) one of the workers replied with the NoA, the ones that answered did agree up to a point: of all the answers, 72% were such that all of their sen- tences ... from which they could be extracted. One purpose of our project was to take part in the development of QA systems by providing the community with a new type of corpus. The cor- pus includes not only...

Ngày tải lên: 20/02/2014, 09:20

... describe the current stat~s of METAL, e~phasizing the results of the most recent post-edltors' evaluation, and will briefly indicate some future directions for the system. A 6-page German ... Bennett, "The LRC Machine Translation System: An Application of S~ate -of- the-Art Text and Natural Language Processing Techniques to the Translation of Technical Manuals, " Working Paper ... quality machine translation system, for market introduction in 1985. This paper wlll describe the curren~ statn/s o f METAL, including the results of the most recent evaluation, and will briefly...

Ngày tải lên: 01/04/2014, 00:20

... access to HIV services. Development of the referral system The process of designing the referral system was led by researchers from the Tanzanian National Institute of Med- ical Research, and included ... management of the referral system, liaison with stakeholders, and the data collection and analysis. He co-wrote the first draft of the manuscript. AW contributed to the design of the referral system, ... Central Page 1 of 9 (page number not for citation purposes) Journal of the International AIDS Society Open Access Research From HIV diagnosis to treatment: evaluation of a referral system to promote...

Ngày tải lên: 20/06/2014, 08:20

... performance evaluation process consists of the following steps. Some of the concepts of this and the next subsection have been reused and modified from the work in [13]: (1) selection of the evaluation ... precision of a single clock cycle. Cycle- accuracy guarantees that at any given clock cycle, the state of the simulated system model is identical w ith the state of the real system. System- level ... real-time embedded systems can be represented as discrete event systems and propose an automated method for verification of dense time properties of such systems. The model of computation (MoC)...

Ngày tải lên: 21/06/2014, 20:20

... (km) 2 4 6 8 10 12 14 16 18 20 22 24 Figure 14: UL CIR value of HAP system (CIR HT ) interfered by the terrestrial system. CDF of CIR H of different frequency reuse scheme in HAP cellular system 0 0.2 0.4 0.6 0.8 1 Pr (CIR ... Networking 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 CIR HT of HAP system interfered by terrestrial system (N = 4) −30 −20 −10 0 10 20 30 Distance from SPP of HAP (km) −30 −20 −10 0 10 20 30 Distance from SPP of HAP (km) 2 4 6 8 10 12 14 16 18 20 22 24 Figure ... Article Performance Evaluation of WiMAX Broadband from High Altitude Platform Cellular System and Terrestrial Coexistence Capability Z. Yang, A. Mohammed, and T. Hult School of Engineering, Blekinge Institute of...

Ngày tải lên: 21/06/2014, 23:20

Ngày tải lên: 09/08/2014, 02:21