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111.
Theory of parametric frequency down conversion of light 总被引:1,自引:0,他引:1
112.
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114.
Lee OK 《Journal of applied measurement》2003,4(1):10-23
The longitudinal measurement of ability growth requires that the measures that are taken at the various time points be obtained using the same yardstick. Tests given for this purpose, therefore, need to be equated. The popular practice still in use for the purpose of equating tests, is the grade-equivalent. This paper compares the observation of children's growth in reading using grade-equivalents with that using Rasch Simultaneous Vertical Equating procedure. It is found that grade equivalents differ much more between two different test forms compared to ability measures obtained using Rasch Simultaneous Vertical Equating. It is also found that the spread of students' grade-equivalents, increased over the years as they grow while the standard deviations of their Rasch measures remain relatively constant over the same period of time. Student responses to the ITBS Form 7 and the CPS90 and CPS 91 were used. A total of 5,623 students were tracked over eight years. 相似文献
115.
A framework for distributed manufacturing is proposed to facilitate collaborative product development and production among geographically distributed functional agents using digitalized information. Considering the complexity of products created in a distributed manufacturing scenario, it often requires close collaborations among a number of facilities. In this research work, various functional agents, such as the manufacturability evaluation agent (MEA), manufacturing resource agent (MRA), process-planning agent (PPA), manufacturing scheduling agent (MSA), shop floor agent (SFA), fault diagnosis agent (FDA), etc., can interact coherently for distributed manufacturing. With specific agents having unique functionalities, a manufacturing managing agent (MMA) acts as the centre of this distributed manufacturing system. The MMA agent assists the specific agents’ to work seamlessly and also to collaborate closely with the participating agents. In this way, the production cycle of a part can be optimized from product design to final manufacturing since all the production procedures are considered logically and every procedure is correlated. The agent language based on the knowledge query manipulation language (KQML) includes many pre-defined performatives that ease the participating agents to carry out their tasks intelligently by interpreting commands from one another. Additionally, to ensure the adaptiveness and upgradeability of the system, the internal structure of each functional agent that is based on JATLite is modularized into several components, including a communication interface, central work engine, knowledge base pool, and input/output modifier for possible future methodology enhancements. 相似文献
116.
Zexuan Zhu Yew-Soon Ong Manoranjan Dash 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2007,37(1):70-76
This correspondence presents a novel hybrid wrapper and filter feature selection algorithm for a classification problem using a memetic framework. It incorporates a filter ranking method in the traditional genetic algorithm to improve classification performance and accelerate the search in identifying the core feature subsets. Particularly, the method adds or deletes a feature from a candidate feature subset based on the univariate feature ranking information. This empirical study on commonly used data sets from the University of California, Irvine repository and microarray data sets shows that the proposed method outperforms existing methods in terms of classification accuracy, number of selected features, and computational efficiency. Furthermore, we investigate several major issues of memetic algorithm (MA) to identify a good balance between local search and genetic search so as to maximize search quality and efficiency in the hybrid filter and wrapper MA 相似文献
117.
J. P. Yang J. Q. Mou N. B. Chong Y. Lu H. Zhu Q. Jiang W. G. Kim J. Chen G. X. Guo E. H. Ong 《Microsystem Technologies》2007,13(8-10):733-740
In this paper, we present novel micro-electro-mechanical systems (MEMS) devices for unique probe recording technology, where the 1-D cantilever probe array approach requires a small number of cantilever probe tips for a large media platform and hence has higher reliability. The probe storage system is composed of three key MEMS devices: MEMS XY-stage, linear motor and 1-D cantilever probe array with integrated heater. The design and fabrication process of three MEMS devices are given with prototypes. Their performances are discussed with the experimental results. The compact MEMS XY-stage device can be driven with ±20 μm movement, in X- and Y-directions. The miniature linear motor is smoothly driven to move back and forth at the speed of 20 mm/s and step of 150 μm by 150 mA pulse driving current. The indented (writing) bit size of 100 nm on polymer media is achieved by the prototyped cantilever probe tip with integrated heater. 相似文献
118.
H. Pan Y. Wu Y. Li P. Liu B. S. Ong S. Zhu G. Xu 《Advanced functional materials》2007,17(17):3574-3579
Poly(4,8‐didodecyl‐2,6‐bis‐(3‐methylthiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene) self‐assembled on appropriate substrates from solution and formed highly structured thin films at low temperatures. As an as‐prepared thin‐film semiconductor without thermal annealing, it exhibited excellent field‐effect transistor properties with mobility of ~ 0.15 cm2 V–1 s–1 in thin‐film transistors. 相似文献
119.
X. Liang F. L. C. Ong P. Pillai P. M. L. Chan V. Mancuso G. Koltsidas F. N. Pavlidou L. Caviglione E. Ferro A. Gotta H. Cruickshank S. Iyengar G. Fairhurst 《International Journal of Satellite Communications and Networking》2007,25(4):409-440
This is the second part of the tutorial paper following the previous tutorial paper describing enabling technologies in digital video broadcasting (DVB) system. The paper presents the current and future operational scenarios for DVB via satellite (DVB‐S) system. Review of the current state‐of‐the‐art technologies consisting of integration of broadband Internet and mobile communications and integration of broadband Internet and DVB are given. The future operational scenarios emphasize the fusion of DVB systems with other technologies in terms of network fusion and terminal fusion. For satellite service scenarios, it also takes into consideration mobility management and standard quality‐of‐service mechanism issues, such as integrated services and differentiated services. Several research directions for providing seamless services regardless of network, access technology and terminal in the fusion network are also highlighted in this paper. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
120.
John Case Sanjay Jain Yuh Shin Ong Pavel Semukhin Frank Stephan 《Journal of Computer and System Sciences》2014
Automatic classes are classes of languages for which a finite automaton can decide whether a given element is in a set given by its index. The present work studies the learnability of automatic families by automatic learners which, in each round, output a hypothesis and update a long-term memory, depending on the input datum, via an automatic function. Many variants of automatic learners are investigated: where the long-term memory is restricted to be the current hypothesis whenever this exists, cannot be of length larger than the length of the longest datum seen, or has to consist of a constant number of examples seen so far. Learnability is also studied with respect to queries which reveal information about past data or past computation history; the number of queries per round is bounded by a constant. 相似文献