• Title/Summary/Keyword: 그룹 속도

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Alkali Gelatinization of Starches Isolated from Various Hydration Groups of Milled Rice (수화그룹별 쌀 전분의 알카리 호화)

  • Kim, Sung-Kon;Chung, Hye-Min
    • Applied Biological Chemistry
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    • v.29 no.1
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    • pp.29-35
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    • 1986
  • Viscosity development pattern, in aqueous sodium hydroxide, of rice starches isolated from various hydration groups of milled rice was investigated. The maximum viscosity and viscosity development rate of Japonica rice starches at a given alkali concentration were loswer than those of J/Indica counterparts. The difference in the viscosity development rate of starches by increment of 0.1N (0.02 meq/g) was greater in J/Indica rice starches in comparison with Japonica ones. Viscosity of rice starch was not correlated to that of rice flour and to hydration rate of milled rice.

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Weekday Internet Game Times and Domestic Factors of Middle & High School Students (중고등학생의 평일 인터넷 게임시간과 가정환경 요인)

  • Kim, Eun Yeob;Lee, Jee Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5326-5336
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    • 2012
  • Most middle and high school students in Korea use internet for gaming and recreation. This study aimed to classify middle and high school students according to amount of time they spend playing games and analyze relationship domestic factors. Weekday game times and environmental factors of the adolescents in Korea. The group with average game time of 30 min, 0:30-1:30 hours, 1:30-3:00 hours, over 4:00 hours. Subjects in this study were 6,487 middle and high school students. For the category "thoughts about game characters", the group with average game time of 1:30~3:00 hours replied "not at all" but the group with average game time of over 4:00 hours replied "sometimes", which was significantly different from the previous group. Similarly, for the category "lack of time for homework", the group with average game time of 1:30~3:00 hours replied "not at all", which significantly differed from the "sometimes" response from the group with average game time. For satisfaction with interest, "average" was the most frequent response from all the groups. Analyzing correlation of factors influencing game addiction in subjects with game time showed that factors related to game addiction diagnosis and academic performance were especially different in the group with average game time of over 4:00 hours compared to other groups. Nowadays internet has taken a large and significant part of our life such that a life without internet is hard to imagine, and our dependency on internet has risen at the same time. Accordingly, education on appropriate utilization and correct usage of internet to youths who lack self-control and judgment is very needed.

Design and Implementation of Collaborative Knowledge Management System for Collaborative Learning (협력학습을 위한 협력지식관리시스템의 설계 및 구현)

  • Han, Hee-Seop;Kim, Hyeoncheol
    • The Journal of Korean Association of Computer Education
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    • v.10 no.2
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    • pp.115-123
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    • 2007
  • Collaborative knowledge is continuously producted and modified by group individuals during collaboration and it is also fostered in a radical trust environment like Wiki. The example is Wikipedia. However I found out a big problem as difficulties of exploring when the knowledge space is extended more and more widely. To solve this problem, collaborative knowledge management systems are implemented based on wiki. The one is navigation map that supports the efficient exploring and the another is knowledge map that supports a convergent thinking in a group. In this study, we examined the effectiveness of navigation map and knowledge map.

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An antenna selection scheme considering low feedback rate in MIMO-OFDM systems for Personal Rapid Transit Systems (소형궤도열차 제어를 위한 MIMO-OFDM 시스템에서 낮은 귀환률을 고려한 안테나 선택 기법)

  • Park, Ho-Hwan;Lim, Jong-Kyung;Kim, Baek-Hyun;Yoo, Dong-Kwan;Kwak, Kyung-Sup
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.909-914
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    • 2005
  • This paper proposes an efficient antenna selection scheme for PRT (Personal Rapid Transit) remote control in a wireless MIMO-OFDM systems. Using high correlation among neighboring sub-carriers, transmit antennas are selected by calculation based on the channel response of the center sub-carrier in each subgroup. This scheme reduces complexity of selection algorithm and significantly reduces the feedback channel information with small performance degradation. Especially, when feedback channel rate between a control base and a train is fixed, the proposed scheme can provide a significant advantage in high mobility.

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Design of Flight Software for Heater Control in LEO Satellites (저궤도 관측위성의 히터제어를 위한 위성비행소프트웨어 설계)

  • Lee, Jae-Seung;Shin, Hyun-Kyu;Choi, Jong-Wook;Cheon, Yee-Jin
    • Aerospace Engineering and Technology
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    • v.10 no.1
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    • pp.141-148
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    • 2011
  • LEO satellites have many heaters for thermal control, such as bus module heaters, payload heaters and battery internal heaters. Some of these heaters are controlled by thermisters, and others can be controlled by flight software. These heaters are divided into various types of group according to the location, telemetry variables, flight software logic, power distribution, etc. Thus, it is difficult to find out which heaters are included in a certain group and modify heater control logic for a new/other software developers. This document describes about the general/special control logic for satellite heaters and groups/arrays for heaters.

Performance Enhancement Technique using Iterative Decoding and Maximal Ratio Receive Combining Technique for Multiplexed STBC OFDM Systems (복호 및 최대수신결합을 반복적으로 이용한 Multiplexed STBC OFDM 성능향상 기법)

  • Jung Hyeok-Koo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.5C
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    • pp.391-397
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    • 2005
  • Since space time block code (STBC) technique of a transmission diversity technique was introduced, multiple input multiple output techniques using transmission diversity at the basestation for improving transmission data rate, have been studied extensively. Multiplexed STBC OFDM technique uses multiple groups of two transmit antennas and suppresses the interference signals of other STBC OFDM groups at the receivers. In this paper, I propose a new method of iterative decoding and maximal ratio receive combining technique for multiplexed STBC OFDM systems, and simulated and showed the results in comparison with the conventional methods.

Modified CSD Group Multiplier Design for Predetermined Coefficient Groups (그룹 곱셈 계수를 위한 Modified CSD 그룹 곱셈기 디자인)

  • Kim, Yong-Eun;Xu, Yi-Nan;Chung, Jin-Gyun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.9
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    • pp.48-53
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    • 2007
  • Some digital signal processing applications, such as FFT, request multiplications with a group(or, groups) of a few predetermined coefficients. In this paper, based on the modified CSD algorithm, an efficient multiplier design method for predetermined coefficient groups is proposed. In the multiplier design for sine-cosine generator used in direct digital frequency synthesizer(DDFS), and in the multiplier design used in 128 point $radix-2^4$ FFT, it is shown that the area, power and delay time can be reduced up to 34%.

The Design of Seamless Handoff Algorithm based on Multicast Group Mechanism for Micro Mobility (Micro Mobility 지원을 위한 멀티캐스트 그룹 메커니즘 Seamless 핸드오프 알고리즘 설계)

  • Shin, Dong-Jin;Choi, Sang-Ho;Lim, Sun-Bae;Oh, Jae-Yoon;Song, Byung-Kwon;Jeong, Tae-Eui
    • Proceedings of the Korea Information Processing Society Conference
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    • 2001.04a
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    • pp.523-526
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    • 2001
  • 3GPP2 방식에서는 Macro Mobility 지원을 위하여 MIP를 이용하며 PDSN은 FA의 기능을 수행한다. 이때 하나의 PDSN에서 다른 PDSN으로 MS가 이동할 경우 지원되는 이동성을 Macro Mobility라 하며, POSN 관리 영역 내의 하나의 RN에서 다른 RN으로 이동시에 지원되는 이동성을 Micro Mobility라 한다. 본 논문은 Micro Mobility를 지원하기 위한 멀티캐스트 그룹 메커니즘 기반의 Seamless 핸드오프 알고리즘을 제안하고 있다. 제안된 알고리즘은 MS의 이동방향과 속도를 계산하여, 예상 이동경로에 인접한 RN들을 멀티캐스트 그룹으로 구성하고, 그룹 조인 시점을 최대한 늦춤으로서 망의 효율성을 높인다. 또한, 기존의 멀티캐스트 연결 방법이 가지고 있는 버퍼 오버헤드에 대한 문제점을 해결하기 위해, PDSN은 예상 핸드오프 시간 이후의 데이터만을 전송하며, RN 또한 예상 핸드오프 시간 이후의 데이터만을 버퍼링 한다. 제안된 알고리즘의 Dead Lock Free, Liveness 및 Reliability를 검증하기 위해 State Transition Diagram을 작성하고, 페트리 네트를 이용하였다.

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A Comparative Study on Feature Selection and Classification Methods Using Closed Frequent Patterns Mining (닫힌 빈발 패턴을 기반으로 한 특징 선택과 분류방법 비교)

  • Zhang, Lei;Jin, Cheng Hao;Ryu, Keun Ho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.11a
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    • pp.148-151
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    • 2010
  • 분류 기법은 데이터 마이닝 기술 중 가장 잘 알려진 방법으로서, Decision tree, SVM(Support Vector Machine), ANN(Artificial Neural Network) 등 기법을 포함한다. 분류 기법은 이미 알려진 상호 배반적인 몇 개 그룹에 속하는 다변량 관측치로부터 각각의 그룹이 어떤 특징을 가지고 있는지 분류 모델을 만들고, 소속 그룹이 알려지지 않은 새로운 관측치가 어떤 그룹에 분류될 것인가를 결정하는 분석 방법이다. 분류기법을 수행할 때에 기본적으로 특징 공간이 잘 표현되어 있다고 가정한다. 그러나 실제 응용에서는 단일 특징으로 구성된 특징공간이 분명하지 않기 때문에 분류를 잘 수행하지 못하는 문제점이 있다. 본 논문에서는 이 문제에 대한 해결방안으로써 많은 정보를 포함하면서 빈발패턴에 대한 정보의 순실이 없는 닫힌 빈발패턴 기반 분류에 대한 연구를 진행하였다. 본 실험에서는 ${\chi}^2$(Chi-square)과 정보이득(Information Gain) 속성 선택 척도를 사용하여 의미있는 특징 선택을 수행하였다. 그 결과, 이 연구에서 제시한 척도를 사용하여 특징 선택을 수행한 경우, C4.5, SVM 과 같은 분류기법보다 더 향상된 분류 성능을 보였다.

Evaluation for Rock Cleavage Using Distribution of Microcrack Spacings (V) (미세균열의 간격 분포를 이용한 결의 평가(V))

  • Park, Deok-Won
    • The Journal of the Petrological Society of Korea
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    • v.26 no.3
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    • pp.297-309
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    • 2017
  • Jurassic granite from Geochang was analysed with respect to the characteristics of the rock cleavage. The comprehensive evaluation for rock cleavages was performed through the combination of the 16 parameters derived from the enlarged photomicrographs of the thin section and the spacing-cumulative frequency diagrams. The results of analysis for the representative values of these spacing parameters with respect to the rock cleavage are summarized as follows. First, the above parameters can be classified into group I (spacing frequency (N), total spacing ($1m{\geq}$), constant (a), exponent (${\lambda}$), slope of exponential straight line (${\theta}$), length of line (oa') and trigonometric ratios ($sin{\theta}$, $tan{\theta}$) and group II (mean spacing (Sm), difference value between mean spacing and median spacing (Sm-Sme), density (${\rho}$), lengths of lines (oa and aa'), area of a right-angled triangle (${\Delta}oaa^{\prime}$) and trigonometric ratio($cos{\theta}$). The values of the 8 parameters belonging to group I show an order of H(hardway, H1+H2)