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Verification and test are critical phases in the development of any hardware or software system. This article focuses on black box testing of the control part of hardware and software systems. Black box testing involves specification, test generation, and fault coverage. Finite state machines (FSMs) are commonly used for specifying controllers. FSMs may have shortcomings in modeling complex systems. With the introduction of X-machines, complex systems can be modeled at higher levels of abstraction. An X-machine can be converted into an FSM while preserving the level of abstraction. The fault coverage of a test sequence for an FSM specification provides a confidence level. We propose a fault coverage metric for an FSM specification based on the transition fault model, and using this metric, we derive the coverage of a test sequence. The article also presents a method which generates short test sequences that meet a specific coverage level and then extends this metric to determine the coverage of a test sequence for an FSM driven by an FSM network. We applied our FSM verification technique to a real-life FSM, namely, the fibre channel arbitrated loop port state machine, used in the field of storage area networks.

The vapor-pressure data of iron was measured using the combination of a Knudsen effusion cell and a high-temperature, thermogravimetric balance. Most of the available vapor-pressure data for iron have been taken below 1600 K. In contrast, the current data have been collected from 1573 to 1973 K, and these values should help fill a void in the data near the melting point of iron. Although the measured vapor pressures have a similar temperature dependence as literature values of iron vapor-pressure data, the current data is consistently lower than these previous values by roughly a factor of 2.

AbstractThe alleviation of deformation of thin-walled shell structures by using piezoelectric ring stiffeners was demonstrated in the authors' previous work. The basic idea is to use piezoelectric ring stiffeners bonded to the surface of the shell to counteract the deformation caused by external loads such as gravity, internal pressure, and temperature change. The important issue of how to properly select control voltages within the piezoelectric ring stiffeners is discussed in this article. Instead of using a trial-and-error method, as in the past, here an optimal mechanism is used. By forcing the final deformation to approach a pre-specified deformation, the authors determine a set of optimal control voltages within the piezo-stiffeners. A thin-walled cylindrical shell, subject to its own weight, a non-uniform pressure distribution, and a high temperature increase were designed for computer simulation. Eighteen identical piezoelectric rings disposed along the length of the shell at equal spacing are considered, but there is no limitation on the number, location, and size of the rings in the analysis. Efficient control of the shell's deformation by the piezoelectric rings can be readily achieved through the optimization procedure. The numerical results illustrate that a controllable alleviation of shells' deformation is attainable.

We report here new results that further elucidate the role of buoyancy-driven convective flows in determining the distribution of vapor mole fraction and temperature in the thermal diffusion cloud chamber. A two-dimensional model describing both diffusion and convection in the presence of chamber sidewalls is presented. The model equations are used to analyze 1-butanol and 1-pentanol nucleation data obtained earlier. The results of the investigation show that convective flow is nearly always present and, in the cases considered here, result in a reduction in the value of the calculated critical supersaturation (as compared to the one-dimensional case). The dependence of critical supersaturation with total pressure reported earlier is smaller but is not eliminated.

A technique for structural health monitoring that can detect damage away from a sensor location and during operation of a structure is presented. The technique, Transmittance Function Monitoring, uses vibration measurements to detect damage, but without measuring the excitation force or using a model of the structure. Accelerometers or piezoceramic patches are attached to the structure for sensing, and piezoceramic patches or inertial actuators are used for exciting the structure. The sensor–actuator system actively interrogates the structure using broadband excitation, and transmittance functions between consecutive sensors from the healthy structure are stored as historical data. Changes in the functions are then used to detect, locate and assess damage to the structure. Transmittance functions can be computed from different types of measured structural responses. Here, structural translations and curvatures are used to detect damage on a composite beam. The sensitivity of the two different methods is compared, and the optimal frequency range to detect damage is experimentally determined. In addition, the wavelengths of the structural mode shapes are computed to estimate the highest frequency at which the structural response can be measured by a given length piezoceramic sensor.

Inductive Fault Analysis (IFA) is a systematic Procedure to predict all the faults that are likely to occur in MOS integrated circuit or subcircuit The three major steps of the IFA procedure are: (1) generation of Physical defects using statistical data from the fabrication process; (2) extraction of circuit-level faults caused by these defects; and (3) classification of faults types and ranking of faults based on their likelihood of occurrence Hence, given the layout of an IC, a fault model and a ranked fault list can be automatically generated which take into account the technology, layout, and process characteristics. The IFA procedure is illustrated by its applications to an example circuit. The results from this sample led to some very interesting observations regarding nonclassical faults.

Identification of the complex-stress criterion governing creep fracture in metals has been shown to be of fundamental significance in the assessment of component life. In the present paper the authors consider the problems encountered when deriving the criterion without access to sophisticated complex-stress testing equipment. These have been solved by comparing the results of direct double-shear creep fracture tests with predictions of those results, made on the basis of tensile creep rupture data in association with either an octahedral shear stress criterion or a maximum principal tensile stress criterion. An Al alloy, Cu, a Ni alloy, a Ti alloy, cast iron, and two steels have been investigated at temperatures where creep conditions are operative,. the results have shown that the method may be used to predict, with sufficient accuracy, the complex-stress creep fracture criterion for the metals studied.

The purpose of this study was to determine if the subcutaneous chamber technique would reduce the number of rabbits required for antisera production by enabling serial use of individual animals for multiple antigens. Rabbits were assigned to immunization protocols against two antigens in series that involved combinations of chamber implantation, Freund's adjuvant and injection of antigen either by the subcutaneous route or by direct inoculation into the chamber. Results indicate the systemic immune response to both antigens achieved similar magnitude and duration by use of either Freund's adjuvant or direct inoculation of antigen into the chamber, suggesting that chamber use may be able to replace use of Complete Freund's adjuvant for many antigens. Rabbits re-used for a second antigen were equally successful in production of significant titres in both serum and chamber fluid without evidence of either a significant inflammatory response due to the chronic presence of the implant or a decrease in the yield of antisera harvested from the chamber. These results support the advantages of chamber use as reported by others and demonstrate that the chamber technique can significantly extend the productive life of an individual animal that would otherwise be euthanized following a single use in antisera production.

Initiatives to sequence DNA on a large scale have created a need for increased throughput and decreased costs. One scheme for increasing throughput, multiplex sequencing, involves the processing of a mixture of sequencing templates followed by sequential hybridization to reveal the individual sequence ladders on a membrane. Because multiplex sequencing has not been fully automated, and has not seemed automatable, few sequencing efforts have attempted to exploit it. We describe here a scheme for the automation of multiplex sequencing. Probe hybridized to target DNA is detected via spatially localized enzyme-linked fluorescence. Light output is high enough that imaging is possible with simple instrumentation. Direct imaging within an automated hybridization apparatus is made feasible so that the entire process will be automatic once a multiplex membrane is produced. The technique has the potential to increase severalfold the throughput of automated sequencing instruments required for sequencing the human genome. Copyright 1994, 1999 Academic Press

Spleen cells labeled with 51Cr were used in sensitized syngeneic mice to measure the degree of mononuclear cell infiltration into antigen-challenged tissues. With this method, increased cellular infiltration was found after footpad challenge of mice sensitized with sheep erythrocyte, Escherichia coli, and BCG antigens. Cellular response also was determined by using this technique in the lungs of mice sensitized with sheep erythrocytes and BCG. This procedure offers the opportunity to measure cellular infiltration, whether due to cellular or humoral influences, in tissues not easily accessible to conventional immunological manipulation.

A new recessive hypotrichosis gene in the rat designated fuzzy (fz) is described. Fuzzy is linked to albino (c) in linkage group I with a 18.13 +/- 3.05 percent recombination. After an initial sparse hair coat, the fuzzy animals rapidly become devoid of hair. Histologically the skin of these animals has poorly developed, and often cystic hair follicles that contain accumulations of keratinacious material.

The plasma albumin decreases markedly while the total plasma globulins decrease slightly below control values in the protein-depleted animal. The dogs are very susceptible to disease in the depleted state, a susceptibility which is reduced upon repletion in proteins. The plasma volume drops and the available fluids increase as the total circulating plasma albumin is reduced by the process of depletion. This nutritional edema is corrected rapidly by repletion in plasma albumin.The excretion of urine nitrogen gradually increases during the feeding of protein nitrogen in the repletion period. This gradual increase is the result of a decrease in the utilization of the protein and of an increase in the excretion of nitrogen from body stores. The decrease in urine nitrogen excretion below normal which occurs in the hypoproteinemic dog is primarily the result of a decrease in ammonia and urea nitrogen.