• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1022-1026
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• 2009

우리나라에서는 1980년대 초반부터 비점오염원 원단위를 산정하기 시작하였으나 모두 단일강우 또는 제한된 수의 실측자료만을 이용하였다. 각 토지이용에 따른 비점오염의 유출특성을 충분하게 반영하지 못하였기 때문에 강우량의 변화가 큰 지역의 경우, 강우 특성에 따라 특정 기간에 과도하게 오염부하가 산정될 수 있다. 최근 수질오염의 특징은 과거의 대량 발생원인 점오염에 의한 수질오염에서 도시 강우 유출수나 농경지 등으로부터 대량의 비점오염에 의한 수질오염으로 변화하고 있다. 그러나 비점오염은 점오염과 같이 일정한 출구를 통해 유출되지 않으므로 집중처리에 의한 조절 방법의 적용이 곤란한 형편이다. 본 연구에서는 광산(저탄장) 지역의 모니터링을 실시하여 계절별 비점오염부하 유출특성에 대하여 조사하였고, 오염부하와 EMC 농도를 산정하여 분석하였다. 본 연구는 장기적인 모니터링 과제로 향후 지속적인 모니터링을 실시하여 수질분석과 유량을 측정한다면 광산(저탄장) 지역의 비점오염부하 산정 시 유용한 자료로 활용될 것으로 판단된다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.1
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• pp.37-46
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• 1995

Along with the recent trend of complexity and long distance transmission in power system, dynamic analysis of stability considering the load characteristics is an important subject. In this paper, the influence of the induction motor loads on the power system voltage is investigated. The influence of the inductive load ratio and the inertia of induction motor on the voltage response of the power system are examined, and in the case of the high percentage of the induction motor load, induction motors in the power system can lead to transient voltage instability even under the system condition such as switching operation. The application of static condenser(SC) to prevent the transient voltage instability is introduced.

• Science of Emotion and Sensibility
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• v.10 no.4
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• pp.583-601
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• 2007

The desktop interface is not suitable for the environment in which mobile devices are used commonly with moving, because much attention should be paid for it. And the miniaturizing of mobile devices increases the workload for using them, makes the operation speeds lower and makes more errors. So the study of appropriate level of the input interface for this changing environment is needed. In the aspect of mobile devices. input style and the complexity of the menu hierarchy, this study will look for the way to decrease the workload when doing some primary tasks and using mobile devices simultaneously with moving. The input style was classified into gesture input style, button input style, and pointing input style. The accuracy and speed were measured when doing dual tasks, including a menu searching task and a figure memory task, through one input style of three. By Changing the level of menu hierarchy in the menu searching task, the accuracy of task execution was examined. These Experiments were done in standing state and moving state. In both state the pointing input style was the highest in the accuracy of task execution but the slowest in the speed. In contrast, the gesture input style was not high in the accuracy but the fastest in the speed. This fact shows that the gesture input style is suitable for the condition needed for speedy processing rather than accurate execution when moving.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.640-641
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• 2011

스마트그리드 환경하에서 플러그인 전기 자동차(PEV)는 새로운 도전이자 과제이다. 전 세계적으로 전기 자동차에 대한 관심이 높아지면서 PEV가 전력망에 미치는 영향에 관한 연구가 이루어지고 있다. 본 논문에서는 LA사업자(Load Aggregator)는 소비자들의 부하를 통합적으로 관리하여 에너지 비용을 최소화하며 인센티브 지급을 통한 V2G 서비스를 사용하여 피크 삭감을 유도한다. PEV 운영 비용 최소화와 부하 평탄화를 목적으로 하는 LA사업자에 의한 PEV 충전 부하 관리의 잠재적인 이점들을 평가하며, 최적 충전 제어 방식을 위하여 하루전 시장에서 충전 부하와 V2G 가능 용량을 예측하고 PEV 배터리를 분석하여 모델링하는 방법을 제시하였다. 사례연구에서는 다음의 세 가지 PEV 충전 시나리오 즉, 제어되지 않는 시나리오(퇴근 후 충전), TOU 요금제를 적용한 시나리오와 최적 충전 제어 시나리오에 대해 에너지 비용과 피크 수요 감축 측면에서 비교 평가하였다. 이는 향후 증가하는 PEV로 인한 계통의 경제성 평가 및 신뢰도 평가로 사용할 수 있을 것으로 사료된다.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.600-602
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• 1999

원자력발전 비율이 증가함에 따라 전기에너지의 효율적인 이용과 원자력발전의 경쟁력 제고를 위하여 원자력발전소(이하 원전)의 부하추종운전 필요성이 점점 커지고 있다. G7과제의 하나로 개발되고 있는 차세대원자로(KNGR, Korean Next Generation Reactor)는 경쟁력 있는 원전의 설계를 위하여 "일일부하추종운전 능력의 확보"를 기본 성능요건의 하나로 하여 개발되고 있다. 그러나 수동으로 원자로출력분포를 제어하는 기존 원전의 제어방식으로는 상기목표를 충족시키기 어려워 원자로의 출력분포와 출력을 동시에 제어하는 새로운 자동 제어방식을 도입하였다. 본 논문에 기술된 제어방법은 원자로 출력분포 상태에 따른 비선형 제어방법이 적용되며 목표출력 부근에서의 Oscillatory Behavior 방지를 위해 설정된 Deadband 내에서의 다른 상태변수를 제어하기 위한 알고리즘도 포함된다. 개발된 제어방법의 성능을 확인하기 위해 원자로 증기공급계통 전체를 모델링한 성능분석 Simulator를 이용한 Numerical Simulation을 수행하였다. 일일부하추종운전은 100-50-100%P[$(10{\sim}16)-2-(10{\sim}4)-2$ hr] power cycle over a 24-hour period, 주파수제어는 일반적인 Grid Follow에 대해 Simulation하였다.

• Korean Journal of Cognitive Science
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• v.16 no.3
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• pp.155-174
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• 2005

Oh and Kim (2004) and Woodman and Lurk (2004) demonstrated that spatial working memory (SWM) load Interfered concurrent visual search and that search process also impaired the maintenance of spatial information implying that visual search and SWM task both require access to the same limited-capacity mechanism. Two obvious possibilities have been suggested about what this shared limited-capacity mechanism is: common demand for attention to the locations where the items f9r the two tasks were presented (spatial attention load hypothesis), and common use of working memory to maintain a record of locations have been processed(SWM load hypothesis). To test these two hypothetical explanations, Experiment 1 replicated the mutual interference between visual search and SWM task in spite of difference of procedure with preceding researches; possible areas where the items for two tasks were presented were not separated. In Experiment 2, we presented the items for visual search either in the same quadrants where the items for SWM task had appeared (same-location rendition) or in the different quadrants (different-location condition). As a result, search efficiency was more impaired in the different-location condition than in the same-location condition. The memory accuracy was worse in the different-location rendition than in the same-location rendition. Overall results of study indicate that the mutual interference between SWM and visual search might be related to the overload of spatial attention, but not to that of SWM.

• Journal of the KSME
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• v.24 no.3
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• pp.203-213
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• 1984

도시쓰레기 소각처리는 이미 100년전에 유럽지역에서 시작되었고 원래 환경보존 및 공해방지목적에 연유되어 발전되어 왔다. 그후 국제적 에너지자원의 재평가가 중요시됨에 따라 1960년도를 전후하여 소각에서 발생되는 잉여열을 활용하는 장치개발 및 플랜트의 건설이 유행되어 기저부하로서 쓰레기소각로를 이용한 열병합지역난방 시스템이 유럽, 일본 등지에서 상용화되고 있다. 이와 같이 세계적인 추세와 발맞추어 국토가 협소하고 환경오염, 에너지 보존자원이 부족한 우리나라의 입장은 도시쓰레기 처리문제는 해결되어야 할 가장 중요한 당면과제로 대두하고 있다.

• Management & Information Systems Review
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• v.29 no.4
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• pp.187-205
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• 2010

Empirical study comparing the leadership styles of women an men is a popular on management in organization. Consistent with study comparing women and men on many organizational behavior, I have identified that leadership style from survey. The this study examined follower's perception of the women and men the leadership in organization. More specifically, I examined how male and female follower evaluated the leadership style and effectiveness of women and man, how these evaluations were affected by the degree of stereotypes of the followers toward gender roles, finally the variables affecting the evaluation of the leadership effectiveness. Total 158 follower's participated in this survey to explore these research questions. The results that female evaluator were evaluated higher in the transformational leadership than male evaluator, while the evaluation for man leader was higher than the woman leader in terms of the transactional and task-oriented leadership style. Also, another analysis the gender difference of the organizational member revealed that woman leader better than man was higher leader relational and transformational leadership. However, both male and female followers who were no gender-difference in decision making work, interpersonal work, relation coordination work, consulting work.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.21-32
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• 2010

This study investigated the effects of contiguity and reading mode on cognitive load factors measured by Galvanic Skin Response(GSR). In this study two experimental conditions were imposed to participants to measure cognitive load with the high contiguity picture and low contiguity picture. Thirty-four college students participated to this experiment(experiment group=17, control group=17), and spilt-plot factorial design was applied to control individual difference in galvanic skin response. Tasks of this experiment were reading and summary. The dependent variables were skin conductance response, and perceived difficulty. The independent variables were the degree of contiguity of visual material(high contiguity vs. low contiguity). The major result of this study was identification of a significant difference of GSR with low contiguity condition. Indeed it was identified that more complex reading condition required more cognitive loads. This finding supported that different cognitive process might require different amounts of cognitive loads. For the further research, this study discussed the validity of applying physiological signals to assess cognitive loads and relationships the associated affective reactions.

• Korean Journal of Cognitive Science
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• v.20 no.2
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• pp.125-154
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• 2009

This paper describes the possibility of human physiological data, especially brain-wave activity, to detect cognitive overload, a phenomenon that may occur while learner uses an e-learning system. If it is found that cognitive overload to be detectable, providing appropriate feedback to learners may be possible. To illustrate the possibility, while engaging in cognitive activities, cognitive load levels were measured by EEG (electroencephalogram) to seek detection of cognitive overload. The task given to learner was a computerized listening and recall test designed to measure working memory capacity, and the test had four progressively increasing degrees of difficulty. Eight male, right-handed, university students were asked to answer 4 sets of tests and each test took from 61 seconds to 198 seconds. A correction ratio was then calculated and EEG results analyzed. The correction ratio of listening and recall tests were 84.5%, 90.6%, 62.5% and 56.3% respectively, and the degree of difficulty had statistical significance. The data highlighted learner cognitive overload on test level of 3 and 4, the higher level tests. Second, the SEF-95% value was greater on test3 and 4 than on tests 1 and 2 indicating that tests 3 and 4 imposed greater cognitive load on participants. Third, the relative power of EEG gamma wave rapidly increased on the 3rd and $4^{th}$ test, and signals from channel F3, F4, C4, F7, and F8 showed statistically significance. These five channels are surrounding the brain's Broca area, and from a brain mapping analysis it was found that F8, right-half of the brain area, was activated relative to the degree of difficulty. Lastly, cross relation analysis showed greater increasing in synchronization at test3 and $4^{th}$ at test1 and 2. From these findings, it is possible to measure brain cognitive load level and cognitive over load via brain activity, which may provide atimely feedback scheme for e-learning systems.