Compressed Skewed-Load Delay Test Generation Based on Evolution and Deterministic Initialization of Populations

The current design and manufacturing semiconductor technologies require to test the products against delay related defects. However, complex acpSOC require low-overhead testability methods to keep the test cost at an acceptable level. Skewed-load tests seem to be the appropriate way to test delay faults in these acpSOC because the test application requires only one storage element per scan cell. Compressed skewed-load test generator based on genetic algorithm is proposed for wrapper-based logic cores of acpSOC. Deterministic population initialization is used to ensure the highest achievable aclTDF coverage for the given wrapper and scan cell order. The developed method performs test data compression by generating test vectors containing already overlapped test vector pairs. The experimental results show high fault coverages, decreased test lengths and better scalability in comparison to recent methods

Multi-Cycle at Speed Test

In this research, we focus on the development of an algorithm that is used to generate a minimal number of patterns for path delay test of integrated circuits using the multi-cycle at-speed test. We test the circuits in functional mode, where multiple functional cycles follow after the test pattern scan-in operation. This approach increases the delay correlation between the scan and functional test, due to more functionally realistic power supply noise. We use multiple at-speed cycles to compact K-longest paths per gate tests, which reduces the number of scan patterns. After a path is generated, we try to place each path in the first pattern in the pattern pool. If the path does not fit due to conflicts, we attempt to place it in later functional cycles. This compaction approach retains the greedy nature of the original dynamic compaction algorithm where it will stop if the path fits into a pattern. If the path is not able to compact in any of the functional cycles of patterns in the pool, we generate a new pattern. In this method, each path delay test is compared to at-speed patterns in the pool. The challenge is that the at-speed delay test in a given at-speed cycle must have its necessary value assignments set up in previous (preamble) cycles, and have the captured results propagated to a scan cell in the later (coda) cycles. For instance, if we consider three at-speed (capture) cycles after the scan-in operation, and if we need to place a fault in the first capture cycle, then we must generate it with two propagation cycles. In this case, we consider these propagation cycles as coda cycles, so the algorithm attempts to select the most observable path through them. Likewise, if we are placing the path test in the second capture cycle, then we need one preamble cycle and one coda cycle, and if we are placing the path test in the third capture cycle, we require two preamble cycles with no coda cycles

フィールドにおけるテスト印加と低電力論理BISTに関する研究

Advances in semiconductor process technology have resulted in various aging issues in field operation of Very Large Scale Integration (VLSI) circuits. For example, HCI (Hot carrier injection), BTI (Bias Temperature Instability), TDDB (Time Dependent Dielectric Breakdown) are well-known aging phenomena, and they can increase the circuit delay resulting in serious reliability problems. In order to avoid system failures caused by aging, recent design usually sets a certain timing margin in operational frequency of the circuit. However, it is difficult to determine the size of the proper timing margin because of the difficulty of prediction of its aging speed in actual use that is related to operational environment. Pessimistic prediction may result in performance sacrificing although it will improve the reliability of the system. BIST-based field test is a promising way to guarantee the reliability of the circuit through detecting the aging-induced faults during the circuit operation. However, the field test has a limitation on test application time, which makes it difficult to achieve high test quality. Therefore an effective test application method at field is required. In addition to the requirement of short test application time, the BIST-based field test requires performing at-speed testing in order to detect timing-related defects. However, it is well known that power dissipation during testing is much higher than that in normal circuit operation. Because excessive power dissipation causes higher IR-drop and higher temperature, it results in delay increase during testing, and in turn, causing false at-speed testing and yield loss. While many low power test methods have been proposed to tackle the test power issue, inadequate test power reduction and lower fault coverage still remain as important issues. Moreover, low power testing that just focuses on power reduction is insufficient. When the test power is reduced to a very low level, a timing-related defect may be missed by the test, and a defective circuit will appear to be a good part passing the test. Therefore, appropriate test power control is necessary though it was out of considering in the existing methods. In this dissertation, we first proposed a new test application to satisfy the limitation of short test application time for BIST-based field test, and then we proposed a new low power BIST scheme that focuses on controlling the test power to a specified value for improving the field test quality. In chapter 3, a new field test application method named “rotating test” is presented in which a set of generated test patterns to detect aging-induced faults is partitioned into several subsets, and apply each subset in one test session at field. In order to maximize the test quality for rotating test, we proposed test partitioning methods that refer to two items: First one aims at maximizing fault coverage of each subset obtained by partitioning. Second one aims at minimizing the detection time interval of all faults in rotating test to avoid system failures. Experimental results demonstrated the effectiveness of the proposed partitioning methods. In chapter 4, we proposed a new low power BIST scheme which can control the scan-in power, scan-out power and capture power while keeping test coverage at high level. In this scheme, a new circuit called pseudo low-pass filter (PLPF) is developed for scan-in power control, and a multi-cycle capture test technique is employed to reduce the capture power. In order to control scan-out power dissipated by test responses, we proposed a novel method that selects some flip-flops in scan chains at logic design phase, and fills the selected flip-flops with proper values before starting scan-shift operation so as to reduce the switching activity associated with scan-out. The experimental results for ISCAS-89 and ITC-99 benchmark circuits show that significant scan-in power reduction rate (the original rate of 50% is reduced to 7~8%) and capture power reduction rate (the original rate of 20% is reduced to 6~7%) were derived. With the scan-out controlling method, the scan-out power can be reduced from 17.2% to 8.4%, which could not be achieved by the conventional methods. Moreover, in order to control the test power to the specified rate to accommodate the various test power requirements. A scan-shift power controlling scheme was also discussed. It showed the capability of controlling any scan-shift toggle rate between 6.7% and 50%.九州工業大学博士学位論文 学位記番号:情工博甲第289号　学位授与年月日:平成26年3月25日1. INTRODUCTION|2. PRELIMINARY|3. BIST-BASED FIELD ROTATING TEST FOR AGING-INDUCED FAULT DETECTION|4. TEST POWER REDUCTION FOR LOGIC-BIST|5. SUMMARY九州工業大学平成25年

Technology 2001: The Second National Technology Transfer Conference and Exposition, volume 1

Papers from the technical sessions of the Technology 2001 Conference and Exposition are presented. The technical sessions featured discussions of advanced manufacturing, artificial intelligence, biotechnology, computer graphics and simulation, communications, data and information management, electronics, electro-optics, environmental technology, life sciences, materials science, medical advances, robotics, software engineering, and test and measurement

Recent Advances in Signal Processing

The signal processing task is a very critical issue in the majority of new technological inventions and challenges in a variety of applications in both science and engineering fields. Classical signal processing techniques have largely worked with mathematical models that are linear, local, stationary, and Gaussian. They have always favored closed-form tractability over real-world accuracy. These constraints were imposed by the lack of powerful computing tools. During the last few decades, signal processing theories, developments, and applications have matured rapidly and now include tools from many areas of mathematics, computer science, physics, and engineering. This book is targeted primarily toward both students and researchers who want to be exposed to a wide variety of signal processing techniques and algorithms. It includes 27 chapters that can be categorized into five different areas depending on the application at hand. These five categories are ordered to address image processing, speech processing, communication systems, time-series analysis, and educational packages respectively. The book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Molecular phylogeny of horseshoe crab using mitochondrial Cox1 gene as a benchmark sequence

An effort to assess the utility of 650 bp Cytochrome C oxidase subunit I (DNA barcode) gene in delineating the members horseshoe crabs (Family: xiphosura) with closely related sister taxa was made. A total of 33 sequences were extracted from National Center for Biotechnological Information (NCBI) which include horseshoe crabs, beetles, common crabs and scorpion sequences. Constructed phylogram showed beetles are closely related with horseshoe crabs than common crabs. Scorpion spp were distantly related to xiphosurans. Phylogram and observed genetic distance (GD) date were also revealed that Limulus polyphemus was closely related with Tachypleus tridentatus than with T.gigas. Carcinoscorpius rotundicauda was distantly related with L.polyphemus. The observed mean Genetic Distance (GD) value was higher in 3rd codon position in all the selected group of organisms. Among the horseshoe crabs high GC content was observed in L.polyphemus (38.32%) and lowest was observed in T.tridentatus (32.35%). We conclude that COI sequencing (barcoding) could be used in identifying and delineating evolutionary relatedness with closely related specie

Crab and cockle shells as heterogeneous catalysts in the production of biodiesel

In the present study, the waste crab and cockle shells were utilized as source of calcium oxide to transesterify palm olein into methyl esters (biodiesel). Characterization results revealed that the main component of the shells are calcium carbonate which transformed into calcium oxide upon activated above 700 °C for 2 h. Parametric studies have been investigated and optimal conditions were found to be catalyst amount, 5 wt.% and methanol/oil mass ratio, 0.5:1. The waste catalysts perform equally well as laboratory CaO, thus creating another low-cost catalyst source for producing biodiesel. Reusability results confirmed that the prepared catalyst is able to be reemployed up to five times. Statistical analysis has been performed using a Central Composite Design to evaluate the contribution and performance of the parameters on biodiesel purity

Proceedings of the inaugural construction management and economics ‘Past, Present and Future’ conference CME25, 16-18 July 2007, University of Reading, UK

This conference was an unusual and interesting event. Celebrating 25 years of Construction Management and Economics provides us with an opportunity to reflect on the research that has been reported over the years, to consider where we are now, and to think about the future of academic research in this area. Hence the sub-title of this conference: “past, present and future”. Looking through these papers, some things are clear. First, the range of topics considered interesting has expanded hugely since the journal was first published. Second, the research methods are also more diverse. Third, the involvement of wider groups of stakeholder is evident. There is a danger that this might lead to dilution of the field. But my instinct has always been to argue against the notion that Construction Management and Economics represents a discipline, as such. Granted, there are plenty of university departments around the world that would justify the idea of a discipline. But the vast majority of academic departments who contribute to the life of this journal carry different names to this. Indeed, the range and breadth of methodological approaches to the research reported in Construction Management and Economics indicates that there are several different academic disciplines being brought to bear on the construction sector. Some papers are based on economics, some on psychology and others on operational research, sociology, law, statistics, information technology, and so on. This is why I maintain that construction management is not an academic discipline, but a field of study to which a range of academic disciplines are applied. This may be why it is so interesting to be involved in this journal. The problems to which the papers are applied develop and grow. But the broad topics of the earliest papers in the journal are still relevant today. What has changed a lot is our interpretation of the problems that confront the construction sector all over the world, and the methodological approaches to resolving them. There is a constant difficulty in dealing with topics as inherently practical as these. While the demands of the academic world are driven by the need for the rigorous application of sound methods, the demands of the practical world are quite different. It can be difficult to meet the needs of both sets of stakeholders at the same time. However, increasing numbers of postgraduate courses in our area result in larger numbers of practitioners with a deeper appreciation of what research is all about, and how to interpret and apply the lessons from research. It also seems that there are contributions coming not just from construction-related university departments, but also from departments with identifiable methodological traditions of their own. I like to think that our authors can publish in journals beyond the construction-related areas, to disseminate their theoretical insights into other disciplines, and to contribute to the strength of this journal by citing our articles in more mono-disciplinary journals. This would contribute to the future of the journal in a very strong and developmental way. The greatest danger we face is in excessive self-citation, i.e. referring only to sources within the CM&E literature or, worse, referring only to other articles in the same journal. The only way to ensure a strong and influential position for journals and university departments like ours is to be sure that our work is informing other academic disciplines. This is what I would see as the future, our logical next step. If, as a community of researchers, we are not producing papers that challenge and inform the fundamentals of research methods and analytical processes, then no matter how practically relevant our output is to the industry, it will remain derivative and secondary, based on the methodological insights of others. The balancing act between methodological rigour and practical relevance is a difficult one, but not, of course, a balance that has to be struck in every single paper