• Journal of Korean Elementary Science Education
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• v.27 no.4
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• pp.446-454
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• 2008

The purpose of this study was to examined the effects of different grouping according to the levels of students' achievement in science cooperative learning on students' science academic achievements, science-related attitudes, perceptions of science learning environment and self-efficacies. The results of this study can be summarized as following. First, the homogeneous grouping was more effective than the heterogeneous grouping in improving the science academic achievements of high academic ability students. Second, the homogeneous grouping was more effective than the heterogeneous grouping in improving the science-related attitude of students, especially for low academic ability students. Third, both the homogeneous grouping and the heterogeneous grouping improved the perceptions of science learning environment of students. For low academic ability students, the homogeneous grouping was more effective. Fourth, the homogeneous grouping was more effective than the heterogeneous grouping in improving self-efficacies of students, especially for middle and low academic ability students.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.45-54
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• 1999

In epistatic grouping of uvs genes in A. nidulans based on the sensitivities to 4-NQO, the same epistatic grouping was obtained as those for UV and MMS-sensitivities. Based on the MMS-sensitivities, uvsA demonstrated synergistic interactions to uvsF and uvsH, the UvsF group genes, but exhibited epistatic interactions to uvsB and uvsC. The same epistatic grouping was also seen for uvsI when UV was irradiated after 4h germination of conidia, showing synergistic interactions to uvsH, uvsC, and uvsB. However, epistatic interactions were observed with uvsF, which were different from those obtained in quiescent conidia by UV. Intergenic and intragenic recombination frequencies were normal in uvsI compared with wild type.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.9
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• pp.77-83
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• 1997

Based on the curve segment grouping, an efficient recognition of round objects form partially occuluded round boundaries is proposed. Curve segments are extracted from an image using a criterion based on the intra-segment curvature and local contrast. During the curve segment extraction the boundaries of pratially occluding and occuluded objects are segmented to different curve segments. The extracted segments of constant intra-segment curvature are grouped to different curve segments. The extracted segments of constant intra-segment curvature are grouped nto a round boundary by the proposed grouping algorithm using inter-segment curvature which gives the relatinships among the curve segments of the same round boundary. The 1st and the 2nd order moments are used for the parameter estimation of the best fitted ellipse with round boundary, and then recognition is perfomed based on the estimated parameters. The proposed scheme processes in segment unit and is more efficient in computational complexity and memory requirements those that of the conventional scheme which processed in pixel units. Experimental results show that the proposed technique is very efficient in recognizing the round object sfrom the real images with apples and pumpkins.

• English Language & Literature Teaching
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• v.12 no.4
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• pp.185-210
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• 2006

This study has two purposes. First, it aims to suggest an appropriate approach to English writing education for Korean high school students in a cooperative learning situation. It also aims to suggest what type of learner grouping, either homogeneous or heterogeneous, is appropriate by comparing the learners' writing abilities and the changes of their affective factors after being exposed to cooperative EFL writing instruction. Two homogeneous classes were selected and instructed to write in English for 11 weeks. One was composed of homogeneous small groups based on the students' writing scores, and the other was composed of heterogeneous small groups, again based on the students' writing scores. The results showed that the improvement between the two class types was quite different across different proficiency levels. For example, although there is little difference between the homogeneous and the heterogeneous classes of low and intermediate-level learners in writing ability improvement, high-level students showed a significant difference between the classes. In addition, it was found that class participation correlated significantly to writing ability improvement. Cooperative learning was proved to be an effective writing instructional approach to encourage learners' interest and increase their self-confidence; however, the results did not show any significant differences in learners' affective domain between the homogeneous and the heterogeneous classes. Similarly, the learners' grouping preference was not affected by the grouping method.

• International Journal of Contents
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• v.1 no.1
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• pp.1-5
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• 2005

This paper presents the development and application of electrical resistance imaging techniques for the visualization of two-phase flow fields. Two algorithms, the so-called the mesh grouping and the boundary estimation, are described for potential applications of electrical resistance tomography (ERT) and results from extensive numerical simulations are also presented. In the electrical resistance imaging for two-phase flows, numerical meshes fairly belonging to each phase can be grouped to improve the reconstruction performance. In many cases, the detection of phase boundary is a key subject and a mathematical model to estimate phase boundary can be formulated in a different manner. Our results indicated that the mesh grouping algorithm is effective to enhance computational performance and image quality, and boundary estimation algorithm to determine the phase boundary directly.

• International Journal of Control, Automation, and Systems
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• v.1 no.3
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• pp.339-350
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• 2003

In this paper, we propose a simultaneous multithreading (SMT) architecture that improves instruction throughput by exploiting instruction level parallelism (ILP) and thread level parallelism (TLP). The proposed architecture issues and completes instructions belonging to the same thread in exact program order. The issue and completion policy greatly reduces the design complexity and hardware cost of our architecture, compared with others that employ out-of-order issue and completion. On the other hand, when the instructions belong to different threads, the issue and completion orders for those instructions may not necessarily be identical to the fetch order. The processor issues instructions simultaneously from multiple threads to functional units by exploiting ILP and TLP, and by dynamic resource sharing. That parallel execution notably improves performance and resource utilization with minimal additional hardware cost over the conventional superscalar processors. This paper proposes an SMT architecture with grouping as well as one without grouping. Without grouping, all threads dynamically and flexibly share most resources. On the other hand, in the SMT architecture with grouping, in which resources and threads are divided into several groups for design simplification, resources are shared only among threads belonging to the same group as those resources. Simulation results show that our processors with four and eight threads improve performance by three or more times over the conventional superscalar processor with comparable execution resources and policies, and that reasonable grouping reduces the design complexity of SMT processors with little negative effect on performance.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.4
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• pp.69-87
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• 2006

This paper proposes an effective approach for the part-machine grouping(PMG) based on the non-binary part-machine incidence matrix in which real manufacturing factors such as the operation sequences with multiple visits to the same machine and production volumes of parts are incorporated and each entry represents actual moves due to different operation sequences. The proposed approach adopts Fuzzy ART neural network to quickly create the Initial part families and their machine cells. A new performance measure to evaluate and compare the goodness of non-binary block diagonal solution is suggested. To enhance the poor solution due to category proliferation inherent to most artificial neural networks, a supplementary procedure reassigning parts and machines is added. To show effectiveness of the proposed approach to large-size PMG problems, a psuedo-replicated clustering procedure is designed. Experimental results with intermediate to large-size data sets show effectiveness of the proposed approach.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.1
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• pp.20-26
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• 2005

This paper proposes the heuristic algorithm for the generalized GT problems to consider the restrictions which are given the number of machine cell and maximum number of machines in machine cell as well as minimum number of machines in machine cell. This approach is split into two phase. In the first phase, we use the similarity coefficient which proposes and calculates the similarity values about each pair of all machines and sort these values descending order. If we have a machine pair which has the largest similarity coefficient and adheres strictly to the constraint about birds of a different feather (BODF) in a machine cell, then we assign the machine to the machine cell. In the second phase, we assign parts into machine cell with the smallest number of exceptional elements. The results give a machine-part grouping. The proposed algorithm is compared to the Modified p-median model for machine-part grouping.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2480-2495
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• 2014

This paper describes a hierarchical method for image-based age estimation that combines age group classification and age value estimation. The proposed method uses a coarse-to-fine strategy with different appearance features to describe facial shape and texture. Considering the damage to continuity between neighboring groups caused by fixed divisions during age group classification, a dynamic grouping technique is employed to allow non-fixed groups. Based on the given group, an ordinal hyperplane ranking (OHRank) model is employed to transform age estimation into a series of binary enquiry problems that can take advantage of the intrinsic correlation and ordinal information of age. A set of experiments on FG-NET are presented and the results demonstrate the validity of our solution.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.7-13
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• 2017

In this paper, we propose a novel dynamic subchannel grouping (DSG) algorithm to maximize the system capacity considering intended proper outage probability for the downlink of enterprise small-cell networks (ESNs). In the proposed DSG scheme, a local gateway (LGW) which is installed in a building dynamically divides the frequency bandwidth into different numbers of subchannel groups (SGs) based on the numbers of small-cell access points (SAPs) and small-cell user equipments (SUEs) per floor. Then, the LGW assigns the SGs to SAPs and the SAPs allocate them to their serving SUEs. Through simulation results, we show that the proposed DSG scheme is appropriate for the ESNs compared to the conventional small-cell networks in which all SAPs use the number of fixed SGs in terms of the system capacity and outage probability.