Evaluation technology of VLSI reliability using hot carrierluminescence

An evaluation technology for VLSI reliability using hot carrier luminescence has been developed. Problems with conventional electrical methods have been solved by the analysis of weak luminescence emitted from operating devices. Two applications are described. First, for the gate oxide evaluation, it is found that the best stress condition is determined by monitoring uniform photon count distribution emitted from the gate capacitors. Second, a method is proposed to find the weakest transistor in an LSI circuit against hot-carrier-induced degradation by counting photon emissions. This method is applied to the analysis of SRAMs (static RAMs) when the transistors to be improved have been detected     

Osteoarthritis associated with mild chondrodysplasia in transgenic mice expressing alpha 1(IX) collagen chains with a central deletion

Type IX collagen, containing molecules of the three distinct polypeptides alpha 1(IX), alpha 2(IX), and alpha 3(IX), is an interesting hybrid extracellular matrix component in cartilage and eye tissues, with the properties of both a proteoglycan and a collagen. The alpha 1 (IX) chain has two forms, as a result of the tissue-specific utilization of two alternative promoters; the alpha 2(IX) chain carries a covalently attached glycosaminoglycan side chain. We have introduced a gene construct controlled by a tissue-specific promoter/enhancer and expressing a truncated alpha 1(IX) chain into mice. Examination of the offspring of two different founders revealed pathological changes similar to osteoarthritis in the articular cartilage of knee joints. In addition, mice homozygous for the transgene developed mild chondrodysplasia (i.e., mild dwarfism, anterior tonguing in the vertebral bodies, and ophthalmopathy). The relative ratio of transgene product to the endogenous alpha 1(IX) chain was approximately one in homozygotes and less than one in heterozygotes. Therefore, the phenotypic severity correlated well with the level of transgene expression. These findings suggest that mutations in type IX collagen genes may cause certain forms of osteoarthritis and chondrodysplasia in humans.     

Model evaluation of CO2 reduction technologies in the Asia-pacific region

Global warming is one of the most serious issues in today's world. Various innovative technologies have been proposed for the reduction of CO₂ emissions and the mitigation of global warming. They include (1) the WENET project, inaugurated in 1993 by the government of Japan, in which electricity produced by photovoltaic systems in vast areas such as the Sahara Desert, or by hydropower systems, is converted to hydrogen for transport to demand sites, and (2) Steinberg's Hydrocarb process, in which fossil fuels and biomass are coprocessed to produce carbon and methanol. While Japan is resource-poor, it is located relatively close to Southeast Asia and Australia, which are large regions with abundant solar energy. This paper describes an investigation of the prospects for the adoption of these innovative technologies by Japan and surrounding resource regions in the next 30 to 40 years. An optimizing energy model is developed for the purpose, and the simulation results provide several interesting suggestions regarding Japan's future strategy for combatting global warming.     

Studies on photodegradation of vitamin K1. I. Determination of vitamin K1 by gas-liquid chromatography (author''s transl)

Glucosyl sphingosine was isolated from the spleen of a patient with adult-type Gaucher's disease. The yield of purified glucosyl sphingosine was 9.3 nmoles/g wet tissue. The gas chromatography-chemical ionization mass spectrum of acetylated glucosyl sphingosine showed peaks due to the presence of ions formed by successive loss of acetic acid (mass 60) from the molecular ion (QM+, 714). Fragments from acetylated sugar, m/e 331, and from the sphingosine residue, m/e 306, were also detected. The GC-CI mass spectrum of the trimethylsilyl derivative of glucosyl sphingosine showed peaks due to the molecular ion (QM+, 822), ions from the sugar moiety (m/e 361, 271), and ions from the sphingosine base (m/e 264, 280). Fragmentation analysis of the purified sample by GC-EI and GC-CI mass spectrometry confirmed the structure glucopyranosyl(1 leads to 1)-1,3-dihydroxy-2-amino-4-octadecene.     

Perforation repair comparing mineral trioxide aggregate and amalgam using an anaerobic bacterial leakage model

The purpose of this study was to evaluate the ability of mineral trioxide aggregate (MTA) and amalgam to seal furcal perforations in extracted human molars using an anaerobic bacterial leakage model. Furcal perforations were made in 39 maxillary and mandibular human molars with a high-speed bur. These were randomly divided into two experimental groups of 18, with the remaining three teeth used as positive controls. Experimental group 1 was repaired with MTA and group 2 with amalgam. Three additional teeth without perforations served as negative controls. A dual chamber anaerobic bacterial leakage model was assembled. Brain heart infusion broth with yeast extract, hemin, menadione, and the chromogenic indicator bromcresol purple was used as the culture broth for Fusobacterium nucleatum. Eight of 18 amalgam samples leaked, whereas none of the 18 MTA samples leaked. MTA was significantly better than amalgam in preventing leakage of F. nucleatum past furcal perforation repairs.     

Robot language from the standpoint of FA system development—An outline of FA-BASIC

A new unified FA (Factory Automation) language has been developed. The language is suited for robot control, vision system control and programmable controller (PC) control and enables a unified means for programming. The language is called FA-BASIC and has common functions such as expression, control structure and input/output statement based on BASIC language.

FA-BASIC is composed of three subsystems: FA-BASIC/R for robot control, FA-BASIC/V for vision system control and FA-BASIC/C for PCs.

Many languages have been developed up to now, but most of them were aimed at single purposes. These single purpose languages were too limited when developing an integrated FA system, because several languages and different program-making methods must be mastered.

Using FA-BASIC, programming with mutual interconnections between robots, PCs and vision devices is done by the one common method.

In this paper, the basic design concept and functions of FA-BASIC will be presented, along with the features of FA-BASIC/R and on outline of a robot control system using a standard mechanism-independent intermediate language and standard fundamental modules. Also, for easy programming, an off-line programming system with graphical aids and a menu-selection method which require no special effort to master will be introduced as the only present-day universal robot programming method.     

Performance/Reliability Measures for Fault-Tolerant Computing Systems

Some fault-tolerant computing systems are discussed and existing reliability measures are explained. Some performance/reliability measures are introduced. Several systems are compared by using numerical examples with the new measures.     

s-Shaped Software Reliability Growth Models and Their Applications

The s-shaped growth curves of detected software errors can be observed in software testing. The delayed s-shaped and inflection s-shaped software reliability growth models based on a nonhomogeneous Poisson process are discussed. The software reliability growth types of the models are investigated in terms of the error detection rate per error. In addition, a viable method for the software quality assessment, which integrates the capture-recapture method and the models above, is discussed, and its application to actual test data is illustrated.