Computational models are commonly used in engineering design and scientific discovery activities for simulating complex physical systems in disciplines such as fluid mechanics, structural dynamics, heat transfer, nonlinear structural mechanics, shock physics, and many others. These simulators can be an enormous aid to engineers who want to develop an understanding and/or predictive capability for complex behaviors typically observed in the corresponding physical systems. Simulators often serve as virtual prototypes, where a set of predefined system parameters, such as size or location dimensions and material properties, are adjusted to improve the performance of a system, as defined by one or more system performance objectives. Such optimization or tuning of the virtual prototype requires executing the simulator, evaluating performance objective(s), and adjusting the system parameters in an iterative, automated, and directed way. System performance objectives can be formulated, for example, to minimize weight, cost, or defects; to limit a critical temperature, stress, or vibration response; or to maximize performance, reliability, throughput, agility, or design robustness. In addition, one would often like to design computer experiments, run parameter studies, or perform uncertainty quantification (UQ). These approaches reveal how system performance changes as a design or uncertain input variable changes. Sampling methods are often used in uncertainty quantification to calculate a distribution on system performance measures, and to understand which uncertain inputs contribute most to the variance of the outputs. A primary goal for Dakota development is to provide engineers and other disciplinary scientists with a systematic and rapid means to obtain improved or optimal designs or understand sensitivity or uncertainty using simulationbased models. These capabilities generally lead to improved designs and system performance in earlier design stages, alleviating dependence on physical prototypes and testing, shortening design cycles, and reducing product development costs. In addition to providing this practical environment for answering system performance questions, the Dakota toolkit provides an extensible platform for the research and rapid prototyping of customized methods and meta-algorithms
標簽： Optimization and Uncertainty Quantification
上傳時間： 2016-04-08
上傳用戶：huhu123456
In this paper we present a classifier called bi-density twin support vector machines (BDTWSVMs) for data classification. In the training stage, BDTWSVMs first compute the relative density degrees for all training points using the intra-class graph whose weights are determined by a local scaling heuristic strategy, then optimize a pair of nonparallel hyperplanes through two smaller sized support vector machine (SVM)-typed problems. In the prediction stage, BDTWSVMs assign to the class label depending on the kernel density degree-based distances from each test point to the two hyperplanes. BDTWSVMs not only inherit good properties from twin support vector machines (TWSVMs) but also give good description for data points. The experimental results on toy as well as publicly available datasets indicate that BDTWSVMs compare favorably with classical SVMs and TWSVMs in terms of generalization
標簽： recognition Bi-density machines support pattern vector twin for
上傳時間： 2019-06-09
上傳用戶：lyaiqing
This book describes the applications of the fundamental interactions of electromagnetic waves and materials as described in the preceding volume, “Basic Electromagnetism and Materials”. It is addressed to students studying masters or doctorate courses in electronics, electromagnetism, applied physics, materials physics, or chemical physics. In particular, this volume analyzes the behavior of materials in the presence of an electromagnetic field and related applications in the fields of electronics, optics, and materials physics.
標簽： Electromagnetism Materials Applied and
上傳時間： 2020-05-26
上傳用戶：shancjb
The working title of this book was Channel Equalization for Everyone. Channel equalization for everyone? Well, for high school students, channel equalization provides a simple, interesting example of how mathematics and physics can be used to solve real-world problems.
標簽： Equalization Channel
上傳時間： 2020-05-26
上傳用戶：shancjb
By inventing the wireless transmitter or radio in 1897, the Italian physicist Tomaso Guglielmo Marconi added a new dimension to the world of communications. This enabled the transmission of the human voice through space without wires. For this epoch-making invention, this illustrious scientist was honored with the Nobel Prize for Physics in 1909. Even today, students of wireless or radio technology remember this distinguished physicist with reverence. A new era began in Radio Communications.
標簽： Radio Frequency Modulation
上傳時間： 2020-06-01
上傳用戶：shancjb
From its inception, random matrix theory has been heavily influenced by its applications in physics, statistics and engineering. The landmark contributions to the theory of random matrices of Wishart (1928) [311], Wigner (1955) [303], and Mar? cenko and Pastur (1967) [170] were moti- vated to a large extent by practical experimental problems.
上傳時間： 2020-06-01
上傳用戶：shancjb
Electrostatic discharge (ESD) phenomena have been known to mankind since the Greek Empire when Thales of Miletus, one of the Seven Sages of Greece, noticed the attraction of strands of hay to amber, leading to the coining of the word ‘‘electron.’’ In the 17th century, Gilbert and Cabeo addressed the attractive and repulsive nature of electricity. In the 18th century, a rapid increase of interest occurred for scientists in the understanding of electrical physics—Gray, du Fay, Nollet, Musschenbroeck, Franklin, Watson, Aepinus, Canton,
上傳時間： 2020-06-05
上傳用戶：shancjb
Electrostatic discharge (ESD) phenomena have been known to mankind since Thales of Miletus in approximately 600 B.C.E. noticed the attraction of strands of hay to amber. Two thousand six hundred years have passed and the quest to obtain a better under- standing of electrostatics and ESD phenomenon continues. Today, the manufacturing of microelectronics has continued the interest in the field of electrostatic phenomenon spanning factory issues, tooling, materials, and the microelectronic industry
上傳時間： 2020-06-05
上傳用戶：shancjb
In the seven years since the first edition of this book was completed, Electrostatic Discharge (ESD) phenomena in integrated circuits (IC) continues to be important as technologies shrink and the speed and size of the chips increases. The phenom- ena related to ESD events in semiconductor devices take place outside the realm of normal device operation. Hence, the physics governing this behavior are not typ- ically found in general textbooks on semiconductors.
標簽： Integrated Circuits Silicon ESD In
上傳時間： 2020-06-05
上傳用戶：shancjb
The goal of this book is to introduce the simulation methods necessary to describe the behaviour of semiconductor devices during an electrostatic discharge (ESD). The challenge of this task is the correct description of semiconductor devices under very high current density and high temperature transients. As it stands, the book can be no more than a snapshot and a summary of the research in this field during the past few years. The authors hope that the book will provide the basis for further development of simulation methods at this current frontier of device physics.
標簽： Development Protection ESD
上傳時間： 2020-06-05
上傳用戶：shancjb
