Three fast mutual exclusion algorithms using read-modify-write and atomic read/write registers are presented in a sequence, with an improvement from one to the next. The last algorithm is shown to be optimal in minimizing the number of remote memory accesses required in a resource busy period. Remote memory access is the key factor of memory access bottleneck in large shared-memory multiprocess...

1. Overview Typically, a memory request from a processor may need to go through many intermediate interconnect routers, directory node, owner node, etc before it is finally serviced. Current multiprocessors do not give preference to any particular memory request. But certain memory requests are more critical to multiprocessor's performance than other requests [4][5]. Example: memory requests fr...

The aim of this work is to allocate the critical section to distributed processes organized by groups having distinct priorities. Affectation can be made inside a group when there are not requests from groups having a greater priority. This paper discusses some techniques to do this in relation to architecture and number of messages. If there are requests issued from distinct groups, there must...

In the group mutual exclusion problem, each critical section has a type or a group associated with it. Processes requesting critical sections belonging to the same group (that is, of the same type) may execute their critical sections concurrently. However, processes requesting critical sections belonging to different groups (that is, of different types) must execute their critical sections in a...

In an abstract argumentation framework, there are often multiple plausible ways to evaluate (or label) the status of each argument as accepted, rejected, or undecided. But often there exists a critical set of arguments whose status is sufficient to determine uniquely the status of every other argument. Once an agent has decided its position on a critical set of arguments, then essentially the e...

The WebQuest is a student-centered, inquiry-oriented and project-based approach for teaching and learning that students use Web resources to learn school topics. This article reports on the design, implementation and evaluation of a WebQuest teaching approach for chemistry classroom teaching in improving the critical thinking of high school students. A preand post-test design was used where 4-m...

With three or more cyclic processes competing for the critical section, however, there is a danger of individual starvation when the Pand V-operations are so-called ‘weakly implemented’. When the semaphore operations are weakly implemented and a V(m) is executed, which process is allowed to proceed is left undefined when two or more processes are blocked by P(m). .As a result, there is a danger...

This paper describes our experience of testing and debugging an optimizer using comparison checking. Although this study is based on Jaramillo et al.’s work, the experience will help those who test optimizers using this technique. In our implementation, important values during the execution of programs are output as a file trace before and after each optimization. Then a comparison phase checks...

Flaw tolerance refers to a state in which a pre-existing crack-like flaw does not propagate even as the material is stretched to failure near its theoretical strength. Such an optimal scenario can be achieved when the characteristic length scale is reduced to below a critical value. So far, the critical conditions to achieve flaw tolerance have been discussed mostly for homogeneous materials or...