Towards Structural Testing of Superconductor Electronics

Many of the semiconductor technologies are already\ud facing limitations while new-generation data and\ud telecommunication systems are implemented. Although in\ud its infancy, superconductor electronics (SCE) is capable of\ud handling some of these high-end tasks. We have started a\ud defect-oriented test methodology for SCE, so that reliable\ud systems can be implemented in this technology. In this\ud paper, the details of the study on the Rapid Single-Flux\ud Quantum (RSFQ) process are presented. We present\ud common defects in the SCE processes and corresponding\ud test methodologies to detect them. The (measurement)\ud results prove that we are able to detect possible random\ud defects for statistical purposes in yield analysis. This\ud paper also presents possible test methodologies for RSFQ\ud circuits based on defect oriented testing (DOT)

Testing non-nested structural equation models

In this paper, we apply Vuong's (1989) likelihood ratio tests of non-nested models to the comparison of non-nested structural equation models. Similar tests have been previously applied in SEM contexts (especially to mixture models), though the non-standard output required to conduct the tests has limited their previous use and study. We review the theory underlying the tests and show how they can be used to construct interval estimates for differences in non-nested information criteria. Through both simulation and application, we then study the tests' performance in non-mixture SEMs and describe their general implementation via free R packages. The tests offer researchers a useful tool for non-nested SEM comparison, with barriers to test implementation now removed.Comment: 24 pages, 6 figure

Test-Signal Search for Mixed-Signal Cores in a System-on-Chip

The well-known approach towards testing mixed-signal cores is functional testing and basically measuring key parameters of the core. However, especially if performance requirements increase, and embedded cores are considered, functional testing becomes technically and economically less attractive. A more cost-effective approach could be accomplished by a combination of reduced functional tests and added structural tests. In addition, it will also improve the debugging facilities of cores. Basic problem remains the large computational effort for analogue structural testing. In this paper, we introduce the concept of Testability Transfer Function for both analogue as well as digital parts in a mixed-signal core. This opens new possibilities for efficient structural testing of embedded mixed-signal cores, thereby adding to\ud the quality of tests

Structural testing of Business Cycles

In this article, the predictability performance of certain classical business cycle theories are tested against contemporary statistical methods by using Finnish macroeconomic data. Keynesian multiplier- accelerator model derivatives and neo-classical real business cycle models are compared to statistical stochastic time-series methods. Some philosophical considerations on the scientific principles and macroeconomic analysis are extended for applied econometric practice. VAR and SUTSE models are estimated and compared against classical theory implications. It is found that in this case, SUTSE model has a superior forecasting ability and that pure statistical algorithms are the most efficient alternatives for predicting Finnish business cycle data.Business Cycle, Real Business Cycle Theory, VAR, SUTSE, multiplier-acceleration

An Automated Framework for Structural Test-data Generation

Structural testing criteria are mandated in many software development standards and guidelines. The process of generating test data to achieve 100% coverage of a given structural coverage metric is labour-intensive and expensive. This paper presents an approach to automate the generation of such test data. The test-data generation is based on the application of a dynamic optimisation-based search for the required test data. The same approach can be generalised to solve other test-data generation problems. Three such applications are discussed-boundary value analysis, assertion/run-time exception testing, and component re-use testing. A prototype tool-set has been developed to facilitate the automatic generation of test data for these structural testing problems. The results of preliminary experiments using this technique and the prototype tool-set are presented and show the efficiency and effectiveness of this approac

Unit Roots and Structural Breaks: A Survey of the Literature

Since Perron (1989) the time series literature has emphasised the importance of testing for structural breaks in typical economic data sets and pronounced the implications of structural breaks when testing for unit root processes. In this paper we survey recent developments in testing for unit roots taking account of possible structural breaks. In doing so we discuss the distinction between taking structural break dates as exogenously determined, an approach initially adopted in the literature, and endogenously testing break dates. That is, we differentiate between testing for breaks when the break date is known and when it is assumed to be unknown. Also important is the distinction between discrete breaks and gradual breaks. Additionally we describe tests for both single and multiple breaks and discuss some of the pitfalls of the latter.

Analytical testing

Analytical methods for combining flight acceleration and strain data with shake test mobility data to predict the effects of structural changes on flight vibrations and strains are presented. This integration of structural dynamic analysis with flight performance is referred to as analytical testing. The objective of this methodology is to analytically estimate the results of flight testing contemplated structural changes with minimum flying and change trials. The category of changes to the aircraft includes mass, stiffness, absorbers, isolators, and active suppressors. Examples of applying the analytical testing methodology using flight test and shake test data measured on an AH-1G helicopter are included. The techniques and procedures for vibration testing and modal analysis are also described

Improving Visual Field Examination of the Macula Using Structural Information

Purpose: To investigate a novel approach for structure-function modeling in glaucoma to improve visual field testing in the macula. Methods: We acquired data from the macular region in 20 healthy eyes and 31 with central glaucomatous damage. Optical coherence tomography (OCT) scans were used to estimate the local macular ganglion cell density. Perimetry was performed with a fundus-tracking device using a 10-2 grid. OCT scans were matched to the retinal image from the fundus perimeter to accurately map the tested locations onto the structural damage. Binary responses from the subjects to all presented stimuli were used to calculate the structure-function model used to generate prior distributions for a ZEST (Zippy Estimation by Sequential Testing) Bayesian strategy. We used simulations based on structural and functional data acquired from an independent dataset of 20 glaucoma patients to compare the performance of this new strategy, structural macular ZEST (MacS-ZEST), with a standard ZEST. Results: Compared to the standard ZEST, MacS-ZEST reduced the number of presentations by 13% in reliable simulated subjects and 14% with higher rates (≥20%) of false positive or false negative errors. Reduction in mean absolute error was not present for reliable subjects but was gradually more important with unreliable responses (≥10% at 30% error rate). Conclusions: Binary responses can be modeled to incorporate detailed structural information from macular OCT into visual field testing, improving overall speed and accuracy in poor responders. Translational Relevance: Structural information can improve speed and reliability for macular testing in glaucoma practice

Fabrication and evaluation of advanced titanium and composite structural panels

Advanced manufacturing methods for titanium and composite material structures are being developed and evaluated. The focus for the manufacturing effort is the fabrication of full-scale structural panels which replace an existing shear panel on the upper wing surface of the NASA YF-12 aircraft. The program involves design, fabrication, ground testing, and Mach 3 flight service of full-scale structural panels and laboratory testing of representative structural element specimens

X-29A aircraft structural loads flight testing

The X-29A research and technology demonstrator aircraft has completed a highly successful multiphase flight test program. The primary research objective was to safely explore, evaluate, and validate a number of aerodynamic, structural, and flight control technologies, all highly integrated into the vehicle design. Most of these advanced technologies, particularly the forward-swept-wing platform, had a major impact on the structural design. Throughout the flight test program, structural loads clearance was an ongoing activity to provide a safe maneuvering envelope sufficient to accomplish the research objectives. An overview is presented of the technologies, flight test approach, key results, and lessons learned from the structural flight loads perspective. The overall design methodology was considered validated, but a number of structural load characteristics were either not adequately predicted or totally unanticipated prior to flight test. While conventional flight testing techniques were adequate to insure flight safety, advanced analysis tools played a key role in understanding some of the structural load characteristics, and in maximizing flight test productivity