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91.
The thermal and mechanical stability of molybdenum and amorphous silicon (Mo/a-Si) optical multilayers (3 and 4 nm nominal thickness of Mo and Si) at 316 °C were studied by annealing experiments. Growth of amorphous Mo-Si interlayers with a stoichiometry of 12 was observed at the Mo/a-Si interfaces. In addition, residual stresses significantly changed in the crystalline Mo and amorphous Si layers with annealing. High resolution electron microscopy, selected area electron diffraction, and X-ray diffraction of the crystalline Mo revealed that tensile stresses increased from 2 to about 10 GPa in the lateral direction (parallel to the interface plane). The compressive strains that developed in the vertical direction (perpendicular to the interface plane) are consistent with Poisson's ratio. Laser deflectometer measurements of thicker (0.1 m) amorphous silicon layers may indicate compressive-stress relaxation in the amorphous silicon with annealing, consistent with other investigations. Overall, the residual stress in a 40-bilayer film changes from about –0.5 to about +1.5 GPa. Structural transformation after relatively short annealing times at the interfaces in the thin amorphous Mo-Si interlayers may rationalize increased tensile strains in the Mo layers. 相似文献
92.
Nutrition-induced effects on the activity of enzymes of lipogenesis, fatty acid synthase (FAS: EC 2.3.1.85), ATP citrate lyase (ACL: EC 4.1.3.8), malic enzyme (ME; EC 1.1.1.40), glucose-6-phosphate dehydrogenase (G6PDH: EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (PGDH; EC 1.1.1.44) were investigated in liver and interscapular brown adipose tissue (BAT) of rats. The lipogenic enzymes could be grouped into two categories according to their response to dietary manipulations: FAS and ACL, both key enzymes of lipogenesis, responded fast and strongly to dietary manipulations. ME, G6PDH and PGDH, enzymes which also contribute to metabolic pathways other than lipogenesis, responded in a more sustained and less pronounced fashion. Feed deprivation caused the specific activities of lipogenic enzymes to decline several-fold. Refeeding of previously fasted (up to 3 days) animals increased the activities dramatically (10-to 25-fold) to far above pre-fasting levels ("overshoot"). Repetition of the fasting/refeeding regimen increasingly impaired the ability of both tissues to synthesize overshooting enzyme activities in the subsequent refeeding period. The fasting-induced decline of the activities was prevented when sugars were provided to the animals via drinking water. The sugars displayed different effectivities: sucrose = glucose > fructose > maltose > > lactose. Sugars as the sole nutrient after fasting were also able to induce overshooting enzyme activities. Again, activities of FAS and ACL responded in a more pronounced fashion than the other three enzymes. Transition from feeding one diet to feeding a new diet of different composition led to adaptation of the lipogenic enzyme activities to levels characteristic for the new diet. Replacing a low-carbohydrate with a high-carbohydrate diet proceeded with major alterations of enzyme activities. This process of attaining a new level took up to 20 days and involved pronounced oscillations of the specific activities. In contrast, when a high-carbohydrate diet was replaced with another diet. particular one high in fat, transition to new enzyme activities was completed within 2-3 days and proceeded without oscillations. All dietary manipulations caused more pronounced responses in young (35d-old) than in adult (180d-old) animals. 相似文献
93.
This paper presents an assumption/commitment specification technique and a refinement calculus for networks of agents communicating asynchronously via unbounded FIFO channels in the tradition of Kahn. We define two types of assumption/commitment specifications, namely simple and general specifications. It is shown that semantically, any deterministic agent can be uniquely characterized by a simple specification, and any nondeterministic agent can be uniquely characterized by a general specification. We define two sets of refinement rules, one for simple specifications and one for general specifications. The rules are Hoare-logic inspired. In particular the feedback rules employ invariants in the style of a traditional while-rule. Both sets of rules have been proved to be sound and also (semantic) relative complete. Conversion rules allow the two logics to be combined. This means that general specifications and the rules for general specifications have to be introduced only at the point in a system development where they are really needed. 相似文献
94.
S. Yuan B.T. Skinner S. Huang D.K. Liu G. Dissanayake H. Lau D. Pagac 《Advanced Engineering Informatics》2011,25(3):413-426
This paper proposes a practical job grouping approach, which aims to enhance the time related performance metrics of container transfers in the Patrick AutoStrad container terminal, located in Brisbane, Australia. It first formulates a mathematical model of the automated container transfers in a relatively complex environment. Apart from the consideration on collision avoidance of a fleet of large vehicles in a confined area, it also deals with many other difficult practical challenges such as the presence of multiple levels of container stacking and sequencing, variable container orientations, and vehicular dynamics that require finite acceleration and deceleration times. The proposed job grouping approach aims to improve the makespan of the schedule for yard jobs, while reducing straddle carrier waiting time by grouping jobs using a guiding function. The performance of the current sequential job allocation method and the proposed job grouping approach are evaluated and compared statistically using a pooled t-test for 30 randomly generated yard configurations. The experimental results show that the job grouping approach can effectively improve the schedule makespan and reduce the total straddle carrier waiting time. 相似文献
95.
By modeling mass transfer phenomena, we simulate solids and liquids dissolving or changing to other substances. We also deal with the very small‐scale phenomena that occur when a fluid spreads out at the interface of another fluid. We model the pressure at the interfaces between fluids with Darcy's Law and represent the viscous fingering phenomenon in which a fluid interface spreads out with a fractal‐like shape. We use hybrid grid‐based simulation and smoothed particle hydrodynamics (SPH) to simulate intermolecular diffusion and attraction using particles at a computable scale. We have produced animations showing fluids mixing and objects dissolving. 相似文献
96.
In a 2008 paper, Walmsley argued that the explanations employed in the dynamical approach to cognitive science, as exemplified
by the Haken, Kelso and Bunz model of rhythmic finger movement, and the model of infant preservative reaching developed by
Esther Thelen and her colleagues, conform to Carl Hempel and Paul Oppenheim’s deductive-nomological model of explanation (also
known as the covering law model). Although we think Walmsley’s approach is methodologically sound in that it starts with an
analysis of scientific practice rather than a general philosophical framework, we nevertheless feel that there are two problems
with his paper. First, he focuses only on the deductivenomological model and so neglects the important fact that explanations
are causal. Second, the explanations offered by the dynamical approach do not take the deductive-nomological format, because
they do not deduce the explananda from exceptionless laws. Because of these two points, Walmsley makes the dynamical explanations
in cognitive science appear problematic, while in fact they are not. 相似文献
97.
We propose a visualization based approach for digital signature authentication. Using our method, the speed and pressure aspects of a digital signature process can be clearly and intuitively conveyed to the user for digital signature authentication. Our design takes into account both the expressiveness and aesthetics of the derived visual patterns. With the visual aid provided by our method, digital signatures can be authenticated with better accuracy than using existing methods—even novices can examine the authenticity of a digital signature in most situations using our method. To validate the effectiveness of our method, we conducted a comprehensive user study which confirms positively the advantages of our approach. Our method can be employed as a new security enhancement measure for a range of business and legal applications in reality which involve digital signature authorization and authentication. 相似文献
98.
Immunity-based hybrid evolutionary algorithm for multi-objective optimization in global container repositioning 总被引:1,自引:0,他引:1
Eugene Y.C. Wong Henry S.C. Yeung Henry Y.K. Lau 《Engineering Applications of Artificial Intelligence》2009,22(6):842-854
The development of evolutionary algorithms for optimization has always been a stimulating and growing research area with an increasing demand in using them to solve complex industrial optimization problems. A novel immunity-based hybrid evolutionary algorithm known as Hybrid Artificial Immune Systems (HAIS) for solving both unconstrained and constrained multi-objective optimization problems is developed in this research. The algorithm adopts the clonal selection and immune suppression theories, with a sorting scheme featuring uniform crossover, multi-point mutation, non-dominance and crowding distance sorting to attain the Pareto optimal front in an efficient manner. The proposed algorithm was verified with nine benchmarking functions on its global optimal search ability as well as compared with four optimization algorithms to assess its diversity and spread. Sensitivity analysis was also carried out to investigate the selection of key parameters of the algorithm. It is found that the developed immunity-based hybrid evolutionary algorithm provides a useful means for solving optimization problems and has successfully applied to the problem of global repositioning of containers, which is one of a constrained multi-objective optimization problem. The developed HAIS will assist shipping liners on timely decision making and planning of container repositioning operations in global container transportation business in an optimized and cost effective manner. 相似文献
99.
Fault based testing aims at detecting hypothesized faults based on specifications or program source. There are some fault
based techniques for testing Boolean expressions which are commonly used to model conditions in specifications as well as
logical decisions in program source. The MUMCUT strategy has been proposed to generate test cases from Boolean expressions.
Moreover, it detects eight common types of hypothesized faults provided that the original expression is in irredundant disjunctive
normal form, IDNF. Software practitioners are more likely to write the conditions and logical decisions in general form rather
than IDNF. Hence, it is interesting to investigate the fault detecting capability of the MUMCUT strategy with respect to general
form Boolean expressions. In this article, we perform empirical studies to investigate the fault detection capability of the
MUMCUT strategy with respect to general form Boolean expressions as well as mutated expressions. A mutated expression can
be obtained from the original given Boolean expression by making a syntactic change based on a particular type of fault.
T. Y. Chen obtained his BSc and MPhil from the University of Hong Kong, MSc and DIC from the Imperial College of Science and Technology, PhD from the University of Melbourne. He is currently a Professor of Software Engineering at the Swinburne University of Technology. Prior to joining Swinburne, he has taught at the University of Hong Kong and the University of Melbourne. His research interests include software testing, debugging, maintenance, and validation of requirements. M. F. Lau received the Ph.D. degree in Software Engineering from the University of Melbourne, Australia. He is currently a Senior Lecturer in the Faculty of Information and Communication Technologies, Swinburne University of Technology, Australia. His research publications have appeared in various scholarly journals, including ACM Transactions on Software Engineering and Methodology, The Journal of Systems and Software, The Computer Journal, Software Testing, Verification and Reliability, Information and Software Technology, Information Sciences, and Information Processing Letters. His research interests include software testing, software quality, software specification and computers in education. K. Y. Sim received his Bachelor of Engineering in Electrical, Electronics and Systems from the National University of Malaysia in 1999 and the Master of Computer Science from the University of Malaya, Malaysia in 2001. Currently, he is a Senior Lecturer in the School of Engineering, Swinburne University of Technology, Sarawak Campus, Malaysia. His current research interests include software testing and information security. C. A. Sun received the PhD degree in Computer Software and Theory in 2002 from Beijing University of Aeronautics and Astronautics, China; the bachelor degree in Computer and Its application in 1997 from University of Science and Technology Beijing, China. He is currently an Assistant Professor in the School of Computer and Information Technology, Beijing Jiaotong University, China. His research areas are software testing, software architecture and service-oriented computing. He has published about 40 referred papers in the above areas. He is an IEEE member. 相似文献
M. F. LauEmail: |
T. Y. Chen obtained his BSc and MPhil from the University of Hong Kong, MSc and DIC from the Imperial College of Science and Technology, PhD from the University of Melbourne. He is currently a Professor of Software Engineering at the Swinburne University of Technology. Prior to joining Swinburne, he has taught at the University of Hong Kong and the University of Melbourne. His research interests include software testing, debugging, maintenance, and validation of requirements. M. F. Lau received the Ph.D. degree in Software Engineering from the University of Melbourne, Australia. He is currently a Senior Lecturer in the Faculty of Information and Communication Technologies, Swinburne University of Technology, Australia. His research publications have appeared in various scholarly journals, including ACM Transactions on Software Engineering and Methodology, The Journal of Systems and Software, The Computer Journal, Software Testing, Verification and Reliability, Information and Software Technology, Information Sciences, and Information Processing Letters. His research interests include software testing, software quality, software specification and computers in education. K. Y. Sim received his Bachelor of Engineering in Electrical, Electronics and Systems from the National University of Malaysia in 1999 and the Master of Computer Science from the University of Malaya, Malaysia in 2001. Currently, he is a Senior Lecturer in the School of Engineering, Swinburne University of Technology, Sarawak Campus, Malaysia. His current research interests include software testing and information security. C. A. Sun received the PhD degree in Computer Software and Theory in 2002 from Beijing University of Aeronautics and Astronautics, China; the bachelor degree in Computer and Its application in 1997 from University of Science and Technology Beijing, China. He is currently an Assistant Professor in the School of Computer and Information Technology, Beijing Jiaotong University, China. His research areas are software testing, software architecture and service-oriented computing. He has published about 40 referred papers in the above areas. He is an IEEE member. 相似文献
100.
We introduce Process Overview, a situation awareness characterisation of the knowledge derived from monitoring process plants. Process Overview is based on observational studies of process control work in the literature. The characterisation is applied to develop a query-based measure called the Process Overview Measure. The goal of the measure is to improve coupling between situation and awareness according to process plant properties and operator cognitive work. A companion article presents the empirical evaluation of the Process Overview Measure in a realistic process control setting. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA based on data collected by process experts.
Practitioner Summary: The Process Overview Measure is a query-based measure for assessing operator situation awareness from monitoring process plants in representative settings. 相似文献