检索结果-内蒙古大学图书馆

Frontiers in Education (FIE) Conference

作者： D.L. Evans C. Midkiff R. Miller J. Morgan S. Krause J. Martin B.M. Notaros D. Rancour K. Wage Arizona State Univ. Center for Research on Education in Science Math Engineering and Technology (CRESMET) Tempe AZ Department of Mechanical Engineering Univ. of Alabama Tuscaloosa AL Colorado School of Mines Golden CO Department of Mechanical Engineering Texas A&M Univ. College Station TX Arizona State Univ. Tempe AZ Mechanical Engineering Univ. of Wisconsin Madison WI Electrical Engineering Univ. Massachusetts-Dartmouth Dartmouth MA Electrical and Computer Engineering Department George Mason Univ. Fairfax VA

One of the hindrances to reform in science, technology, engineering and mathematics (STEM) education is the absence of good assessment instruments that can measure the value added to student learning by new ways of teaching important material. The well-known Force Concept Inventory (FCI) assessment instrument is a good model of an instrument that can be used to check on student's understanding of basic concepts in a discipline. This panel session paper discusses work in progress by the panel members and their co-developers to construct FCI-like Concept Inventories in each of the disciplines of thermodynamics, systems and signals, strength of materials, electromagnetics, circuits, materials, fluid mechanics, and transport processes.

关键词： Instruments Educational technology Mechanical engineering Materials science and technology Mathematics Physics education Continuous improvement Continuing education Electromagnetic measurements Eyes

来源：评论

学校读者我要写书评

暂无评论

Pockets of flexibility in workflow specification 20th

引用

20th International Conference on Conceptual Modeling, ER 2001

作者： Sadiq, Shazia Sadiq, Wasim Orlowska, Maria School of Computer Science and Electrical Engineering Australia Distributed Systems Technology Center The University of Queensland QLD4072 Australia Department of Computer Science Hong Kong University of Science and Technology Hong Kong

ISBN: (纸本)3540428666

Workflow technology is currently being deployed in quite diverse domains. However, the element of change is present in some degree and form in almost all domains. A workflow implementation that does not support the process of change will not benefit the organization in the long run. Change can be manifested in different forms in workflow processes. In this paper, we first present a categorization of workflow change characteristics and divide workflow processes into dynamic, adaptive and flexible processes. We define flexibility as the ability of the workflow process to execute on the basis of a loosely, or partially specified model, where the full specification of the model is made at runtime, and may be unique to each instance. To provide a modeling framework that offers true flexibility, we need to consider the factors, which influence the paths of (unique) instances together with the process definition. We advocate an approach that aims at making the process of change part of the workflow process itself. We introduce the notion of an open instance that consists of a core process and several pockets of flexibility, and present a framework based on this notion, which makes use of special build activities that provide the functionality to integrate the process of defining a change, into the open workflow instance. © Springer-Verlag Berlin Heidelberg 2001.

关键词： Specifications

来源：评论

学校读者我要写书评

暂无评论

Classification on data with biased class distribution 1

引用

12th European Conference on Machine Learning, ECML 2001

作者： Vucetic, Slobodan Obradovic, Zoran School of Electrical Engineering and Computer Science Washington State University PullmanWA99164 United States Center for Information Science and Technology Temple University PhiladelphiaPA19122 United States

ISBN: (数字)9783540447955

ISBN: (纸本)3540425365

Labeled data for classification could often be obtained by sampling that restricts or favors choice of certain classes. A classifier trained using such data will be biased, resulting in wrong inference and sub-optimal classification on new data. Given an unlabeled new data set we propose a bootstrap method to estimate its class probabilities by using an estimate of the classifier’s accuracy on training data and an estimate of probabilities of classifier’s predictions on new data. Then, we propose two methods to improve classification accuracy on new data. The first method can be applied only if a classifier was designed to predict posterior class probabilities where predictions of an existing classifier are adjusted according to the estimated class probabilities of new data. The second method can be applied to an arbitrary classification algorithm, but it requires retraining on the properly resampled data. The proposed bootstrap algorithm was validated through experiments with 500 replicates calculated on 1,000 realizations for each of 16 choices of data set size, number of classes, prior class probabilities and conditional probabilities describing a classifier’s performance. Applications of the proposed methodology to a benchmark data set with various class probabilities on unlabeled data and balanced class probabilities on the training data provided strong evidence that the proposed methodology can be successfully used to significantly improve classification on unlabeled data. © Springer-Verlag Berlin Heidelberg 2001.

关键词： Classification (of information)

来源：评论

学校读者我要写书评

暂无评论

Self-assembled quantum dot transformations via anion exchange

Journal of Vacuum Science & Technology B: Microelectronics a...

引用

Journal of Vacuum science & technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena 2001年第4期19卷 1463-1466页

作者： Jeng-Jung Shen April S. Brown Yongqian Wang Zhong L. Wang School of Electrical and Computer Engineering Microelectronics Research Center Georgia Institute of Technology Atlanta Georgia 30332 School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia 30332

We report the effect of dissimilar anion anneals on the properties of layered quantum dot structures exhibiting vertical self-organization. Such anneals may provide an additional means of controlling dot properties, such as composition, size, and position. In addition, the modification of surface strain is critical to the subsequent nucleation of dots after the initial seed layer. Anion exchange may modify the strain at the semiconductor surface. We find that the effects of P2 and As4 anneals on InAs quantum dot size distributions are different. P2 anneals at relatively high temperatures (350 °C) can cause the loss of the three-dimensional morphology due to surface exchange. P2 anneals at lower temperatures (300 °C) appear to improve the uniformity of the dot size distribution. This behavior is not observed for anneals under As4. The dot size uniformity decreases by annealing dots under As4 at 300 °C.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Scalable integrated region-based image retrieval using IRM and statistical clustering 01

Scalable integrated region-based image retrieval using IRM a...

引用

1st ACM/IEEE-CS Joint Conference on Digital Libraries, JCDL 2001

作者： Wang, James Z. Du, Yanping School of Information Sciences and Technology Pennsylvania State University University Park PA 16801 United States Department of Computer Science and Engineering E-Business Research Center United States Department of Electrical Engineering United States Cisco Systems Inc. United States

ISBN: (纸本)1581133456

Statistical clustering is critical in designing scalable image retrieval systems. In this paper, we present a scalable algorithm for indexing and retrieving images based on region segmentation. The method uses statistical clustering on region features and IRM (Integrated Region Matching), a measure developed to evaluate overall similarity between images that incorporates properties of all the regions in the images by a region-matching scheme. Compared with retrieval based on individual regions, our overall similarity approach (a) reduces the influence of inaccurate segmentation, (b) helps to clarify the semantics of a particular region, and (c) enables a simple querying interface for region-based im- age retrieval systems. The algorithm has been implemented as a part of our experimental SIMPLI city image retrieval system and tested on large-scale image databases of both general-purpose images and pathology slides. Experiments have demonstrated that this technique maintains the accuracy and robustness of the original system while reducing the matching time significantly. Copyright 2001 ACM.

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

Investigations of langanite and langatate materials for use in SAW device applications

Investigations of langanite and langatate materials for use ...

引用

IEEE Symposium (IUS) Ultrasonics

作者： D.C. Malocha M.P. da Cunha D. Puccio K. Casey Center for Applied Acoustoelectronic Technology School of Electrical Engineering and Computer Science University of Central Florida Orlando FL USA Department of Electrical and Computer Engineering University of Maine Orono ME USA

ISBN: (纸本)0780371771

This paper will present recent results and investigations of langanite (LGN) and langatate (LGT) materials for use in SAW device applications. These substrates offer new possibilities for device applications given their slower phase velocities, higher coupling and high temperature operation without degradation of the piezoelectric properties. This paper will present recent results on the extraction of SAW material parameters and device performance for various cut angles. The SAW parameter extraction approach used for these experiments is summarized. Measured resonator Q of the order of 4000 has been obtained with the currently designed devices on Y-cut, showing promising behavior for these materials and orientations. Delay line data is used to extract the phase velocity, coupling coefficient and transducer capacitance. The work discusses the correlation between measured phase velocity, electromechanical coupling coefficient and IDT capacitance, and the predicted parameter performance. Measured SAW resonator temperature coefficient of delay (TCD) data will be presented and compared to expected values for the selected cut angles and propagation directions. The results reported are obtained from LGN and LGT materials from Crystal Photonics, Inc., (CPI) which provides boules that are typically clear, transparent and free of visible defects.

关键词： Surface acoustic waves Capacitance Temperature measurement Surface acoustic wave devices Degradation Parameter extraction Current measurement Q measurement Delay lines Data mining

来源：评论

学校读者我要写书评

暂无评论

Sensitivity analysis for extraction of material constants for trigonal crystal classes

Sensitivity analysis for extraction of material constants fo...

引用

IEEE International Frequency Control Symposium

作者： D.C. Malocha M.P. da Cunha Center for Applied Acoustoelectronic Technology School of Electrical Engineering and Computer Science University of Central Florida Orlando FL USA Department of Electrical & Computer Engineering University of Maine Orono ME USA

There have been a number of published results of the material constants of quartz and more recently, of langasite (LGS), langanite (LGN) and langatate (LGT). Many of the constants reported to date do not discuss the approach or inherent accuracies of their measurements. The stiffness parameter extraction can be obtained using well-known equations given velocity and density data. Assuming the known material density, four of the stiffness constants can be obtained directly from single mode velocity data in a given cut direction using time-echo measurement techniques and are only a function of the mode time delay measurement accuracy. However, c/sub 14/ and c/sub 13/ extraction are more complicated and must be obtained from multiple mode velocity measurements and calculations. In addition, there are several equations using different longitudinal and shear mode velocities that can be used for the parameter extraction of the stiffness constant. This indicates that the extraction is a function of the time delay measurement accuracy and the sensitivity to the velocities used in the calculations. Based on a sensitivity analysis, it is shown that it is best to use the equations using shear mode velocities, rather than longitudinal velocities, in calculations to reduce sensitivity to measurement inaccuracies.

关键词： Sensitivity analysis Crystalline materials Velocity measurement Data mining Delay effects Parameter extraction Time measurement Differential equations Crystals Materials science and technology

来源：评论

学校读者我要写书评

暂无评论

Measurements and predictions of SAW parameters and device performance on LGT-X substrates

Measurements and predictions of SAW parameters and device pe...

引用

IEEE International Frequency Control Symposium

作者： D.C. Malocha M.P. da Cunha E.L. Adler D. Puccio K. Knapp Department of Electrical and Computer Engineering University of Central Florida Orono ME USA Department of Electrical and Computer Engineering University of Maine Orono ME USA Center for Applied Acoustoelectronic Technology School of Electrical Engineering and Computer Science University of Central Florida Orlando FL USA

SAW material parameters have been extracted for LGT X-cut material at various propagation angles. The extracted parameters of velocity, coupling and TCD give good correlation to predicted results based on fundamental LGT material measurements previously reported. SAW delay lines, resonators and transversely coupled resonator (TCR) have been fabricated and the initial results from experiments are presented. The results indicate that the LGT material parameters previously reported will yield reliable predictions, although the precise temperature effects are not at the same level of refinement as in quartz. Based on device results, the current LGT material used is of a high quality and suitable for SAW device applications.

关键词： Surface acoustic waves Surface acoustic wave devices Delay lines Frequency measurement Radio frequency Transducers Testing Probes Scattering parameters electrical resistance measurement

来源：评论

学校读者我要写书评

暂无评论

ML estimation and correction of frequency offset for MC-CDMA systems over fading channels

ML estimation and correction of frequency offset for MC-CDMA...

引用

IEEE Conference on Vehicular technology (VTC)

作者： Qingjiang Tian K. Ben Letaief School of Electrical and Computer Engineering Purdue University Indianapolis West Lafayette IN USA Center for Wireless Information Technology The Department of Electrical and Electronic Engineering Hong Kong University of Science and Technology Hong Kong China

Multi-carrier code division multiple access (MC-CDMA) has been proposed as one of the air interface candidates for the third generation wireless communication systems. However, MC-CDMA systems suffer a lot of performance degradation due to carrier frequency offsets. In this paper, we derive the likelihood function for the carrier frequency offset for MC-CDMA systems for the downlink over Rayleigh flat fading channels. We also propose a gradient algorithm to estimate and minimize the carrier frequency offset in a tracking mode. Simulation results show that system performance can be improved significantly even with only a few iterations.

关键词： Frequency estimation Maximum likelihood estimation Multicarrier code division multiple access Fading Degradation Downlink Information technology System performance Multiaccess communication computer interfaces

来源：评论

学校读者我要写书评

暂无评论

On the minimization of SOPs for bi-decomposable functions

On the minimization of SOPs for bi-decomposable functions

引用

Asia and South Pacific Design Automation Conference

作者： T. Sasao J.T. Butler Center for Microelectronic Systems and Department of Computer Science and Electronics Kyushu Institute of Technology Fukuoka Japan Department of Electrical and Computer Engineering Naval Postgraduate School Montreal CA USA

ISBN: (纸本)0780366336

A function f is AND bi-decomposable if it can be written as f(X/sub 1/,X/sub 2/)=h/sub 1/(X/sub 1/)h/sub 2/(X/sub 2/). In this case, a sum-of-products expression (SOP) for f is obtained from minimum SOPs (MSOP) for h/sub 1/ and h/sub 2/ by applying the law of distributivity. If the result is an MSOP, then the complexity of minimization is reduced. However, the application of the law of distributivity to MSOPs for h/sub 1/ and h/sub 2/ does not always produce an MSOP for f. We show an incompletely specified function of n(n-1) variables that requires at most n products in an MSOP, while 2/sup n-1/ products are required by minimizing the component functions separately. We introduce a new class of logic functions, called orthodox functions, where the application of the law of distributivity to MSOPs for component functions of f always produces an MSOP for f. We show that orthodox functions include all functions with three of fewer variables, all symmetric functions, all unate functions, many benchmark functions, and few random functions with many variables.

关键词： Hydrogen

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：