• Title/Summary/Keyword: grouping.

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A Study of Recognition About Students' Ability Grouping (능력별 집단편성에 대한 교사와 학생의 인식)

  • Kim, Dal-Hyo
    • Journal of Fisheries and Marine Sciences Education
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    • v.19 no.3
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    • pp.390-402
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    • 2007
  • According to the paradigm of Neo-liberalism, the issue of ability grouping has grown more and more in education of Korea. And because of the influence of ability grouping, now ability grouping is enforcing partially in the subjects of English and Mathematics. But ability grouping is going to expand to the all subjects. So, it is very important that how teachers and students are recognize about partial ability grouping in the subjects of English and Mathematics. Because that information about partial ability grouping can guide direction for the future educational policy. The purpose of this study was to actually analyze teacher's and students' recognition of partial ability grouping in the subjects of English and Mathematics. To accomplish this purpose, 622 middles school students and 552 teachers were sampled. As a tool of investigation, questionnaires about teacher's and students' recognition of partial ability grouping had made by researcher of this study were used. And as processing of data, t-test, F-test, Scheff-test were used. The result of this study is as follow. First, teachers who are experiencing ability grouping recognized more negative about ability grouping than teachers who are not experiencing ability grouping. Second, students who have low ability recognized more negative about ability grouping than students who have high ability. Third, teachers who are experiencing ability grouping recognized more ineffective about ability grouping than teachers who are not experiencing ability grouping. Fourth, students who have low ability recognized more ineffective about ability grouping than students who have high ability.

The Effects of Different Grouping in Elementary Science Cooperative Learning (초등학교 과학 협동 학습에서 소집단 구성을 달리한 효과)

  • Lee, Hyeng-Cheol;Moon, Joo-Young;Bae, Jin-Ho
    • 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.

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An Efficient Lot Grouping Algorithm for Steel Making in Mini Mill (철강 Mini Mill 에서의 효율적인 작업 단위 편성)

  • Park, Hyung-Woo;Hong, Yu-Shin;Chang, Soo-Young;Hwang, Sam-Sung
    • Journal of Korean Institute of Industrial Engineers
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    • v.24 no.4
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    • pp.649-660
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    • 1998
  • Steel making in Mini Mill consists of three major processing stages: molten steel making in an electric arc fuenace, slab casting in a continuous caster, and hot rolling in a finishing mill. Each processing stage has its own lot grouping criterion. However, these criteria in three stages are conflicting with each other. Therefore, delveloping on efficient lot grouping algorithm to enhance the overall productivity of the Mini Mill is an extremely difficult task. The algorithm proposed in this paper is divided into three steps hierarchically: change grouping, cast grouping, and roll grouping. An efficient charge grouping heuristic is developed by exploiting the characteristics of the orders, the processing constraints and the requirements for the downstream stages. In order to maximaize the productivity of the continuous casters, each cast must contain as many charges as possible. Based on the constraint satisfaction problem technique, an efficient cast grouping heuristic is developed. Each roll consists of two casts satisfying the constraints for rolling. The roll grouping problem is formulated as a weighted non-bipartite matching problem, and an optimal roll grouping algorithm is developed. The proposed algorithm is programmed with C language and tested on a SUN Workstation with real data obtained from the H steel works. Through the computational experiment, the algorithm is verified to yield quite satisfactory solutions within a few minutes.

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Model Grouping in a Mixed-model Assembly Line (조립생산 시스템에서의 혼합 모델 그룹화)

  • Kim, Yearn-Min;Seo, Yoon-Ho
    • IE interfaces
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    • v.9 no.2
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    • pp.39-45
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    • 1996
  • This paper investigates the problems of grouping N products on an assembly line with an objective of maximizing the option grouping rate. Before developing a mixed model grouping algorithm, simulation studies are committed for developing operating rules and evaluating the layout production systems. A mixed model grouping algorithm is suggested and it is applied to the color selection lane in automobile production system, which reveals a high mixed model grouping rate.

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Clothing Silhouette Image Evaluation related to Life Space (생활공간에 따른 의복실루엣이미지 평가)

  • Park, Young-Sil
    • Fashion & Textile Research Journal
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    • v.2 no.3
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    • pp.246-252
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    • 2000
  • The purpose of this study was to analyze the characteristics of the factor structure in Clothing Silhouette Image and the differences of Image Evaluation related to Grouping of Line and Grouping of Body Emphasis using Silhouette Image Factor and Life Space as variables. Clothing Silhouette Image was estimated by the photographs of 9 Life Spaces ${\times}$ 23 Clothing Silhouettes with 15 semantic differentiated by-polar scales. The major finding were : The factor structure of Clothing Silhouette Image were found to include 4 factor dimensions-Capability Evaluation, Function, Activity. It was clear that Silhouette Image were affected by Life Spaces. There were the differences of Image Evaluation related to Grouping of Line and Grouping of Body Emphasis. There were the differences of Life Space Evaluation related to Grouping of Line and Grouping of Body Emphasis. Therefore it is important to considerate Life Space for selecting Clothing Silhouette.

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Design and Implementation of a Web-based Access Control Service (웹 기반의 접근 제어 서비스에 대한 설계 및 구현)

  • 김흥기;이용환;민덕기
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.04a
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    • pp.208-210
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    • 2001
  • 본 논문은 기존에 운영되고 있는 접근 제한을 고려하지 않고 만들었던 웹사이트를 회전 접근 관리가 가능한 웹사이트로 확장하는 방법을 제안한다. 제시하는 방법은 확장에 필요한 모듈들을 컴포넌트 방식으로 추가하여 기존의 사이트의 수정이 필요 없이 회원관리가 가능하도록 한다. 특히 기존의 ACL(Access Control List)에 없는 새로운 방식인 Resource Grouping 방식을 제시하여 좀더 체계적이고 일괄적인 리소스 관리가 가능하게 한다. 이 Resource Grouping 방식은 Simple Resource Grouping, Resource Grouping With Attributes, Resource Grouping with Parameter로 세부 분류되어 소개된다.

Improvement of Resource Utilization by Dynamic Spectrum Hole Grouping in Wideband Spectrum Cognitive Wireless Networks (광대역 스펙트럼 인지 무선망에서 동적 스펙트럼홀 그룹핑에 의한 자원이용률 향상)

  • Lee, Jin-yi
    • Journal of Advanced Navigation Technology
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    • v.24 no.2
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    • pp.121-127
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    • 2020
  • In this paper, we propose a dynamic spectrum hole grouping method that changes the grouping range of spectrum hole according to the resources amount required by secondary users in wideband spectrum cognitive wireless networks, and then the proposed method is applied to channel allocation for the secondary user service. The proposed method can improve waste of resources in the existing static spectrum hole grouping in virtue of grouping dynamically as much the predicted spectrum holes resources as secondary users require. Simulation results show that channel allocation method with the proposed dynamic grouping outperforms that with the static grouping method in resources utilization under acceptable secondary user service performance.

Development of a Real-time Grouping System of Rice Crop Canopy Chlorophyll Contents

  • Sung J.H.;Jung I.G.;Lee C.K.
    • Agricultural and Biosystems Engineering
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    • v.6 no.1
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    • pp.8-14
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    • 2005
  • This study was carried out to develop a real-time grouping system of chlorophyll contents of rice crop canopy for precision agriculture. The system measured reflected light energy of a rice canopy on a paddy field from visual to near-infrared range and analyzed the collected information of chlorophyll contents of rice crop canopy with given position data. The four filters, 560 nm $({\pm}10nm)$, 650 nm $({\pm}25nm)$, 700 nm $({\pm}12nm)$, and 850 nm $({\pm}40nm)$, were used for a multiple regression to estimate the chlorophyll contents of rice crop canopy. Every $0.2m^2$ area of the open field was inspected at a distance of 1 m above the rice canopy. According to the results of verification test, the chlorophyll content grouping by a commerical chlorophyll meter (SPAD) and by the developed system showed 58.7% match for five-stage chlorophyll contents of rice crop canopy grouping and 93.5% for the $five{\pm}1-stage$ grouping. In addition, the results showed 63.0% match for three-stage grouping and 100.0% for the $three{\pm}1-stage$ grouping.

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Mode Selection Technique Between Antenna Grouping and Beamforming for MIMO Communication Systems (다중 입출력 시스템에서 안테나 그룹화와 빔 형성 사이의 모드 선택 기법)

  • Kim, Kyung-Chul;Lee, Jung-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.2A
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    • pp.147-154
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    • 2009
  • Antenna grouping algorithm is hybrid of beamforming and spatial multiplexing. In antenna grouping system, we partition $N_t$ transmit antennas into $N_r$ groups and use beamforming in a group, spatial multiplexing between groups. We can transmit $N_r$ data streams in the $N_t{\times}N_r$ antenna grouping system. With antenna grouping, we can achieve diversity gain through beamforming, and high spectral efficiency through spatial multiplexing. But if channel is ill-conditioned or there are some correlations between antennas, the performance of antenna grouping is seriously degraded and in that case, beamforming is the best transmit strategy. By selecting the antenna grouping mode when channel is well-conditioned and by selecting the beamforming mode when channel is ill-conditioned, we can prevent serious fluctuation of BER performance caused by varying channel condition and achieve the best BER performance. In this paper, we investigate mode selection algorithm which can select antenna grouping mode or beamforming mode. we also propose a simple mode selection criterion.

A connection caching technique using host grouping (호스트 그루핑을 이용하는 연결 캐슁 기법)

  • 양수미;조유근
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.9
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    • pp.2373-2384
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    • 1996
  • Connection caching technique is widely used to reduce the overhead incurred by frequency connection establishment in distributed computing environment using connection oriented protocol. We present an efficient connection caching scheme where we divide the system into several host groups and connection between the hosts in the same group is kept prior to others. In other words it makes the connection kept longer by sharing the connection use information between hosts in the same group. Every host group consists of hosts which have heavy intercommunication. And we present performance evaluation of the effect of host grouping upon connection caching and performance comparison of various grouping in several aspects includingmeanservice request interarrival time, mean service time, group size, grouping and type of group. Simulation results show that host grouping is effective in evrey performance criterion and proper grouping of hosts enhances the performance. We also present analysis results for Markov process model of our scheme which are consistent with the simulation results.

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