Thermal Monitoring of Self-Checking Systems

With the increasing power density in integrated systems resulting from scaling down, the occurrence of field failures due to overheating has considerably increased. Faulty operation can be prevented by on-line temperature monitoring. This paper deals with questions of on-line temperature monitoring in safety-critical systems. First the possible temperature sensors are reviewed and basic principles of self-checking systems including such sensors are detailed, then a new temperature sensor cell with extremely good parameters designed especially for DfTT applications is presented. The basic questions of integrating thermal sensors into self-checking systems are also discussed.     

用于疏通油水井的脉冲放电技术

评价了各种不同的解堵技术，指出冲击波解堵是一种很有发展前途的技术。介绍了液中脉冲放电产生冲击波的基本原理，并由此研制出了一套井下脉冲放电油水井处理设备样机。通过现场试验，表明用冲击波疏通油井能较好地解除油井污染，提高采收率。     

浅谈试验室对混凝土拌合站的质量管理

从水泥、粗细集料、水、外加剂等方面阐述了试验室对拌合站所用原材料的质量控制，论述了试验室对拌合站计量设备的质量管理，并对拌合站混凝土的质量控制、混凝土试件制作等方面进行了介绍，以真正的管理好混凝土拌合站。     

可燃气体检测报警系统的分析和检修

分析可燃气体检测报警系统的组成和检修方法，并列举了根据故障现象进行分析和检修的实例。     

Current ISI and monitoring technologies in European energy industries

This paper reviews available information on the state of practice of inservice material property monitoring performed in European energy industries. Current practice includes a range of standard nondestructive testing and monitoring methods, improved remote sampling and surveillance specimen testing, and new monitoring techniques which are emerging from ongoing development programs. These new technologies include ultrasonic, positron annihilation, neutron diffraction, and magnetic techniques.     

The integral experiment on beryllium with D-T neutrons for verification of tritium breeding

A clean benchmark experiment on beryllium was performed with D-T neutrons at the FNS facility of the Japan Atomic Energy Agency. The main objective was to verify the integral data related to the tritium production on lithium isotopes. Tritium production rates, as well as activation reaction rates were measured inside the beryllium assembly that was shaped as a pseudo-cylindrical slab with an area-equivalent diameter of 628 mm and a thickness of 355 mm. Experimental results were analyzed with a three-dimensional Monte Carlo transport code MCNP-4C and FENDL/MC-2.0, JENDL-3.2/3.3 neutron transport libraries. Evaluation of reaction rates was based on the cross section data taken from the JENDL Dosimetry File and ENDF B-VI data libraries. Analysis shows that all calculation combinations (transport and activation cross section libraries) used for evaluation of reaction rates give data that is agreeable with measured values within 10%.     

A method for evaluating the mechanical performance of thin-walled titanium tubes

A method which was developed to compare the stress–strain properties of three types of thin-walled, commercially pure titanium tubes is presented. The tubes were of types intended for use in large heat-exchanger applications and were to be subjected to significant plastic deformation during subsequent assembly processes. It had been anticipated that small differences in chemical composition and tube-drawing treatment would produce quite different characteristics. It is known that the properties of titanium can exhibit considerable degrees of anisotropy, especially for wrought products; although axial properties of the materials could be evaluated using standard test equipment and procedures, a novel testing system had to be designed to allow the circumferential properties to be assessed. Significant differences between tube types were observed and anisotropic material behaviour was apparent.     

Diagnostic Data Compression Techniques for Embedded Memories with Built-In Self-Test

A system-on-chip (SOC) usually consists of many memory cores with different sizes and functionality, and they typically represent a significant portion of the SOC and therefore dominate its yield. Diagnostics for yield enhancement of the memory cores thus is a very important issue. In this paper we present two data compression techniques that can be used to speed up the transmission of diagnostic data from the embedded RAM built-in self-test (BIST) circuit that has diagnostic support to the external tester. The proposed syndrome-accumulation approach compresses the faulty-cell address and March syndrome to about 28% of the original size on average under the March-17N diagnostic test algorithm. The key component of the compressor is a novel syndrome-accumulation circuit, which can be realized by a content-addressable memory. Experimental results show that the area overhead is about 0.9% for a 1Mb SRAM with 164 faults. A tree-based compression technique for word-oriented memories is also presented. By using a simplified Huffman coding scheme and partitioning each 256-bit Hamming syndrome into fixed-size symbols, the average compression ratio (size of original data to that of compressed data) is about 10, assuming 16-bit symbols. Also, the additional hardware to implement the tree-based compressor is very small. The proposed compression techniques effectively reduce the memory diagnosis time as well as the tester storage requirement.     

Trace,failure and testing equivalences for communicating processes

A basic question in the theory of communicating processes is “When should two processes be considered equivalent?”. Attempts to answer this question have led to the concepts of observation equivalence, bisimulations, testing equivalence, failure equivalence, etc. The main point of this paper is to increase the understanding and motivation for two of these equivalences, namely failure and testing equivalences. The approach starts with the idea that the equivalence of processes should be reducible to the visible sequences of actions which a process performs in various contexts. This idea is implemented by a string-based semantic order for communicating processes where divergence is catastrophic. Under some assumptions about contexts, the resulting semantics is shown to be equivalent to theimproved failure semantics of Brookes and Roscoe⁽¹⁾ and also to themust testing-semantics of Hennessy and DeNicola.^(2–4) This characterization gives independent support for the appropriateness of failures and testing.     

Increasing testing productivity and software quality: A comparison of software testing methodologies within NASA

Pressure to compress the development life cycle and reduce the duration and resources committed to testing lead to experimentation in testing at the NASA Goddard Space Flight Centerís Software Engineering Laboratory. This study investigates the trend to reduce developer testing and increasingly rely upon inspection techniques and independent functional testing to shorten the development life cycle, improve testing productivity, and improve software quality.An approach is developed to conduct this comparison. In particular, the problem faced by software researchers, having a comprehensive characterization of software projects so similar types may be identified for comparative studies, is addressed using expert opinion.