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Reducing Item Exposure in Computerized Adaptive Testing Systems Using Automatic Item Generation 被引量:1
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作者 Harutyun Terteryan 《Computer Technology and Application》 2014年第1期21-24,共4页
This paper studies the technics of reducing item exposure by utilizing automatic item generation methods. Known test item calibration method uses item parameter estimation with the statistical data, collected during e... This paper studies the technics of reducing item exposure by utilizing automatic item generation methods. Known test item calibration method uses item parameter estimation with the statistical data, collected during examinees prior testing. Disadvantage of the mentioned item calibration method is the item exposure; when test items become familiar to the examinees. To reduce the item exposure, automatic item generation method is used, where item models are being constructed based on already calibrated test items without losing already estimated item parameters. A technic of item model extraction method from the already calibrated and therefore exposed test items described, which can be used by the test item development specialists to integrate automatic item generation principles with the existing testing applications. 展开更多
关键词 Item exposure calibration IRT (item response theory) adaptive testing automatic item generation item model.
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Hybrid Surface Mesh Adaptation for Climate Modeling
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作者 Ahmed Khamayseh Valmor de Almeida Glen Hansen 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2008年第4期410-434,共25页
Solution-driven mesh adaptation is becoming quite popular for spatial error control in the numerical simulation of complex computational physics applications,such as climate modeling.Typically,spatial adaptation is ac... Solution-driven mesh adaptation is becoming quite popular for spatial error control in the numerical simulation of complex computational physics applications,such as climate modeling.Typically,spatial adaptation is achieved by element subdivision (h adaptation) with a primary goal of resolving the local length scales of interest.A sec- ond,less-popular method of spatial adaptivity is called'mesh motion'(r adaptation); the smooth repositioning of mesh node points aimed at resizing existing elements to capture the local length scales.This paper proposes an adaptation method based on a combination of both element subdivision and node point repositioning (rh adaptation). By combining these two methods using the notion of a mobility function,the proposed approach seeks to increase the flexibility and extensibility of mesh motion algorithms while providing a somewhat smoother transition between refined regions than is pro- duced by element subdivision alone.Further,in an attempt to support the requirements of a very general class of climate simulation applications,the proposed method is de- signed to accommodate unstructured,polygonal mesh topologies in addition to the most popular mesh types. 展开更多
关键词 surface mesh generation mesh adaptation mesh optimization climate modeling.
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UEs Power Reduction Evolution with Adaptive Mechanism over LTE Wireless Networks
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作者 Ruchi Sachan Chang Wook Ahn 《Journal of Electronic Science and Technology》 CAS CSCD 2018年第1期79-83,共5页
At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the kn... At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the knowledge of how individual phone features consume power. A typical phone feature is that the applications related to multimedia streaming utilize more power while receiving, processing, and displaying the multimedia contents, thus contributing to the increased power consumption. There is a growing concern that current battery modules have limited capability in fulfilling the long-term energy need for the progress on the mobile phone because of increasing power consumption during multimedia streaming processes. Considering this, in this paper, we provide an offline meaning sleep-mode method to compute the minimum power consumption comparing with the power-on solution to save power by implementing energy rate adaptation(RA) mechanism based on mobile excess energy level purpose to save battery power use. Our simulation results show that our RA method preserves efficient power while achieving better throughput compared with the mechanism without rate adaptation(WRA). 展开更多
关键词 Green communication 4 generation long term evolution(4G LTE) networks rate adaptation(RA) power consumption model
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一种基于HGA和数据挖掘的AMG模型 被引量:1
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作者 魏德志 洪联系 +1 位作者 林丽娜 王奇光 《计算机工程》 CAS CSCD 2012年第7期99-101,共3页
提出一种基于数据挖掘和混合遗传算法(HGA)的自适应模型生成(AMG)模型。采用改进的聚类算法,从网络和系统的行为记录中划分出正常/异常行为库,利用HGA从行为库中挖掘出入侵规则加入规则库中,通过混合检测模块进行检测。实验结果证明,该... 提出一种基于数据挖掘和混合遗传算法(HGA)的自适应模型生成(AMG)模型。采用改进的聚类算法,从网络和系统的行为记录中划分出正常/异常行为库,利用HGA从行为库中挖掘出入侵规则加入规则库中,通过混合检测模块进行检测。实验结果证明,该AMG模型能以更高的检测率、更低的误检率检测未知的网络入侵。 展开更多
关键词 数据挖掘 入侵检测 混合遗传算法 自适应模型生成 聚类算法 信息增益
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REVIEW OF HIGH LEVEL FAULT MODELING APPROACHES FOR MIXED-SIGNAL SYSTEMS
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作者 Xia Likun Ian Bell Antony Wilkinson 《Journal of Electronics(China)》 2010年第4期490-497,共8页
In the modern analogue design, Transistor Level Fault Simulation (TLFS) plays the im-portant part since every fault in the whole circuit has to be simulated at that level. Unfortunately, it is a very CPU intensive tas... In the modern analogue design, Transistor Level Fault Simulation (TLFS) plays the im-portant part since every fault in the whole circuit has to be simulated at that level. Unfortunately, it is a very CPU intensive task even though it maintains the high accuracy. Therefore, High Level Fault Modeling (HLFM) and High Level Fault Simulation (HLFS) are required in order to alleviate the efforts of simulation. In this paper, different HLFM approaches are reviewed at the device level during last two decades. We clarify their domains of application and evaluate their strengths and current limitations. We also analyze causes of faults and introduce various test approaches. 展开更多
关键词 High Level Fault modeling (HLFM) Automated model generation (amg)
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Challenges and Technologies in ReservoirModeling 被引量:1
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作者 Larisa V.Branets Sartaj S.Ghai +1 位作者 Stephen L.Lyons Xiao-Hui Wu 《Communications in Computational Physics》 SCIE 2009年第6期1-23,共23页
Reservoir modeling is playing an increasingly important role in developing and producing hydrocarbon reserves.In this paper,we provide a brief overview of some main challenges in reservoir modeling,i.e.,accurate and e... Reservoir modeling is playing an increasingly important role in developing and producing hydrocarbon reserves.In this paper,we provide a brief overview of some main challenges in reservoir modeling,i.e.,accurate and efficient modeling of complex reservoir geometry and heterogeneous reservoir properties.We then present modeling techniques we recently developed in addressing these challenges,including a method for generating constrained Voronoi grids and a generic global scale-up method.We focus on the Voronoi gridding method,which is based on a new constrained Delaunay triangulation algorithm and a rigorous method of adapting Voronoi grids to piecewise linear constraints.The global scale-up method based on generic flows is briefly described.Numerical examples are provided to demonstrate the techniques and the advantage of combining them in constructing accurate and efficient reservoir models. 展开更多
关键词 Reservoir modeling grid generation grid adaptation global scale-up
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