Scalable shared memory LTL model checking

Recent development in computer hardware has brought more widespread emergence of shared memory, multi-core systems. These architectures offer opportunities to speed up various tasks—model checking and reachability analysis among others. In this paper, we present a design for a parallel shared memory LTL model checker that is based on a distributed memory algorithm. To improve the scalability of our tool, we have devised a number of implementation techniques which we present in this paper. We also report on a number of experiments we conducted to analyse the behaviour of our tool under different conditions using various models. We demonstrate that our tool exhibits significant speedup in comparison with sequential tools, which improves the workflow of verification in general.     

A rewriting logic approach to operational semantics

This paper shows how rewriting logic semantics (RLS) can be used as a computational logic framework for operational semantic definitions of programming languages. Several operational semantics styles are addressed: big-step and small-step structural operational semantics (SOS), modular SOS, reduction semantics with evaluation contexts, continuation-based semantics, and the chemical abstract machine. Each of these language definitional styles can be faithfully captured as an RLS theory, in the sense that there is a one-to-one correspondence between computational steps in the original language definition and computational steps in the corresponding RLS theory. A major goal of this paper is to show that RLS does not force or pre-impose any given language definitional style, and that its flexibility and ease of use makes RLS an appealing framework for exploring new definitional styles.     

An overview of the MOP runtime verification framework

This article gives an overview of the, monitoring oriented programming framework (MOP). In MOP, runtime monitoring is supported and encouraged as a fundamental principle for building reliable systems. Monitors are automatically synthesized from specified properties and are used in conjunction with the original system to check its dynamic behaviors. When a specification is violated or validated at runtime, user-defined actions will be triggered, which can be any code, such as information logging or runtime recovery. Two instances of MOP are presented: JavaMOP (for Java programs) and BusMOP (for monitoring PCI bus traffic). The architecture of MOP is discussed, and an explanation of parametric trace monitoring and its implementation is given. A comprehensive evaluation of JavaMOP attests to its efficiency, especially in comparison with similar systems. The implementation of BusMOP is discussed in detail. In general, BusMOP imposes no runtime overhead on the system it is monitoring.     

A 0.1-μm 1.8-V 256-Mb Phase-Change Random Access Memory (PRAM) With 66-MHz Synchronous Burst-Read Operation

A 256-Mb phase-change random access memory has been developed, featuring 66-MHz synchronous burst-read operation. Using a charge pump system, write performance was characterized at a low supply voltage of 1.8 V. Measured initial read access time and burst-read access time are 62 and 10 ns, respectively. The write throughput was 0.5 MB/s with internal times2 write and can be increased to ~2.67 MB/s with times16 write. Endurance and retention characteristics are measured to be 10⁷ cycles and ten years at 99 degC     

Design and implementation of a fault-tolerant magnetic bearing system for turbo-molecular vacuum pump

One of the obstacles for a magnetic bearing for use in a wide range of industrial applications is the failure modes associated with magnetic bearings, which are not expected for conventional passive bearings. These failure modes include electric power outage, power amplifier faults, position sensor faults, and the malfunction of controllers. Fault tolerant magnetic bearing systems have been proposed so that the system can operate in spite of some faults in the system. In this paper, we describe the design and implementation of a fault tolerant magnetic bearing system for a turbo-molecular vacuum pump. The system can cope with actuator/amplifier faults, as well as faults in position sensors, which are the two major fault modes in a magnetic bearing system.     

Statistical design of experiments of acid activation of smectite clay from Serbia and its bleaching capacity

BACKGROUND: Serbian smectite clay has been activated using a response surface method with central composite design. Because, among the criteria of an edible oil, colour is the most important factor in the commercial value of the oil, and since the colour is due to the presence of pigments such as β‐carotene in the crude oil, acid‐activated clay was used for decolourisation of soybean oil. RESULTS: The effects of five parameters, namely, temperature, time, acid strength, solid/liquid ratio and stirring speed, on the process of acid activation of the clay and its bleaching capacity were determined using a statistical model. The results indicated that all parameters were significant factors in the bleaching capacity of acid‐activated clay, and a quadratic polynomial equation for bleaching capacity was obtained by multiple regression analysis. The optimal bleaching capacity was estimated to be 96.61% for an experimental run under the following conditions: activation temperature 80 °C, HCl concentration 4.78 mol L^?1, stirring speed 450 rpm, solid/liquid ratio 1:4.5 and activation time 2.81 h. CONCLUSIONS: The central composite design, regression analysis and response surface method were effective in identifying the optimal conditions for bleaching capacity of acid‐activated smectite. Copyright © 2008 Society of Chemical Industry