• 한국수소및신에너지학회논문집
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• 제21권4호
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• pp.346-353
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• 2010

Hydrogen fueled vehicle was evaluated as one of the next-generation technology that will be able to solve the global warming, depletion of fossil fuel and etc. The practical use of hydrogen fueled vehicle, nevertheless, is being delayed more than expected schedule due to various causes. In order to promote the dissemination of hydrogen fueled vehicle, development status and obstacle factors of practical use for hydrogen fueled vehicles were reviewed and the strategy plans for dissemination promotion were proposed. Hydrogen fueled vehicles are included the hydrogen fuel cell, neat and enriched hydrogen fueled engines. The technicalness, economy, safety, cognizance, system, support and etc were considered in the strategy plans.

• 한국정밀공학회지
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• 제26권8호
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• pp.89-95
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• 2009

In this paper, a navigation algorithm is proposed using RFID tags in indoor environments. Firstly, a stochastic sensor model of RFID is derived and the design factors including the maximum identifiable distance, the identification direction and the read success rate are obtained through experiments. The obstacle avoidance algorithm is developed with consideration of those factors for a variety of RFID antenna configurations and different indoor environments. The algorithm is tested by computer simulations and implemented on a mobile robot.

• 로봇학회논문지
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• 제5권2호
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• pp.127-134
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• 2010

In this paper, a hybrid semi-3D path planning algorithm combining Virtual Tangential Vector(VTV) and fuzzy control is proposed. 3D dynamic environmental factors are reflected to the 2D path planning model, VTV. As a result, the robot can control direction from 2D path planning algorithm VTV and speed as well depending on the fuzzy inputs such as the distance between the robot and obstacle, roughness and slope. Performances and feasibilities of the suggested method are demonstrated by using Matlab simulations. Simulation results show that fuzzy rules and obstacle avoidance methods are working properly toward virtual 3D environments. The proposed hybrid semi-3D path planning is expected to be well applicable to a real life environment, considering its simplicity and realistic nature of the dynamic factors included.

• Nuclear Engineering and Technology
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• 제29권2호
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• pp.110-126
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• 1997

A two-dimensional continuum model for the hydrogen mining phenomena in the containment subcompartment under severe accident conditions has been developed to predict the spatial distribution of the hydrogen concentration. The model can predict the distribution of time-dependent hydrogen concentration for HEDL experiments well. For the simulation of these experiments, the hydrogen is mixed uniform within the test compartment. To predict the extent of non-uniform distribution, the dominant factors such as the geometrical shape of obstacle and velocity of source injection in mixing phenomena are investigated. If the obstacle disturbing the flow of gas mixture exists in the compartment, the uniform distribution of hydrogen might be not guaranteed. The convective circulation of gas flow is separately formed up and down of the obstacle position, which makes a difference of hydrogen concentration between the upper and lower region of the compartment. The recirculation flow must have a considerable mass flow rate relative to velocity of the source injection to sustain the well-mixed conditions of hydrogen. Finally, in order to account for non-uniform distribution of the hydrogen due to the geometrical configuration the maximum-to-average ratio is functionalized.

• 한국건설관리학회논문집
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• 제8권4호
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• pp.176-184
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• 2007

최근 건설 사업에서 시공이전단계인 설계단계 공사비관리의 중요성이 대두되고 있지만, 설계단계 공사비관리를 위한 제도적 장치나 기술수준은 외국에 비해 매우 낙후되어 있다. 전통적으로 건설 사업에서 공사비관리는 시공단계에 국한되어, 설계단계 공사비관리를 위한 기본 틀과 분류 표준, 공사비 데이터 등 인프라가 부족하여 설계단계 공사비관리 업무를 수행하는데 있어 한계가 있다. 따라서 본 연구에서는 국내 설계단계에서 공사비관리가 효율적으로 수행되기 위해 관리되어야 할 주요 영향요인을 도출하고자 하였다. 설계실무자를 대상으로 설문조사를 통해 설계단계 공사비관리 현황과 문제점을 분석하였고, 설계단계 공사비관리 저해항목에 대해 공사비관리 업무에 미치는 영향도를 조사하였다. 요인분석을 통해 5개의 설계단계 공사비관리 주요 영향요인을 도출하여 향후 설계단계 공사비관리 지원도구 및 제도적 기반 구축에 기여할 수 있도록 하였다.

• 가정과삶의질연구
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• 제27권5호
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• pp.207-220
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• 2009

This study investigates the obstacles to implementing family-friendly policies and offering flexible work arrangements and provides policy directions. A survey was conducted of employers at 147 firms, resulting in 42-43 questionnaires being statistically analyzed. Frequencies, means and factor analysis were conducted by SPSSWIN 12.0. The findings are as follows: First, the main obstacle to implementing family-friendly policies was the burden of cost. Second, eight obstacle factors were extracted through factor analysis. They are; lack of replacement workers and concerns about equity issues, nonfamily-friendly culture, no guarantee of the effectiveness of programs, lack of information about the programs or polices, lack of communication and public relations, potential loss of productivity, administrative hassles, and structural obstacles. Third, there was a difference in implementing flexible work arrangements according to the factors of lack of replacement workers and concerns about equity issues and no guarantee of the effectiveness of programs. That is, the firms which didn't have these two obstacles tried to implement flexible work arrangements more than the others.

• 한국국방경영분석학회지
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• 제33권2호
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• pp.1-15
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• 2007

현재 항공작전은 작전에 영향을 미치는 각종 장애요인들을 고려하지 않고 있다. 보다 효율적인 항공전력운용을 위해서 이들 장애요인들을 예상하고 대비한다면 좀 더 실질적인 항공작전 계획수립에 도움이 될 것이다. 본 연구는 이들 장애요인들이 항공전력 산출에 미치는 영향을 파악하여 항공작전 임무수행 능력, 가용전력 파악을 통해 효과적인 진력 운용에 대해 분석하였다. 이를 위하여 시뮬레이션 분석 도구인 AREA 10.0을 사용하였다. 본 연구에서는 항공전력 산출의 장애요인을 기상, 화생방 상황, 항공기 고장, 적 교전 손실의 4가지로 한정하여 분석하였다. 또한 민감도 분석을 통해 전천후 부장 사용 및 화생방 상황 증가에 따른 전력 산출의 변화를 분석하여 전시 항공작전 장애요인이 전력산출에 끼치는 영향에 대해서 연구하였다.

• 한국비블리아학회지
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• 제4권1호
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• pp.23-48
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• 1980

Libraries are social apparatuses made by social needs and functions, each class of services and technology in them were changed and developed variously adapting to chronological conditions. There is reaching the interest about development in the information system to deal with it's all materials effectively, but most of libraries are interfacing from the limit of materials and manpower. Some obstacle factors restrained in the attainment of purposes and is made Sufficiently services by librarians through the information networks for libraries, they devise the utilization of materials widely in libraries and information centers. As the pre-condition of library networks, the mathematical model of organization and it's formular, 29 universities and 7 public libraries in seoul are to make the non-directed and the directed networks, and then the former has 5 groups, the latter has 1 group by the switching center. I studied for the switching centers from 6 groups experimentally. Organization, finances, cataloging and Situation that are some obstacle factors of the information networks for libraries were studied the alternatives of them. When we can have supports of the nation actively for the making networks in geographical and various libraries and get grants of it, many agencies and industries, we can achieve the purpose by social apparatuses in the information society.

• 한국군사과학기술학회지
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• 제13권6호
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• pp.951-957
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• 2010

An optimal path generation method considering the safety of UGV(Unmanned Ground Vehicle) is proposed and demonstrated through examples. Among various functions of UGV, real-time obstacle avoidance is a key issue to realize realistic scenario in FCS(Future Combat Systems). A two-dimensional narrow corridor environment is considered as a test field. For each step of UGV movement, two objectives are considered: One is to minimize the distance to the target and the other to maximize the distance to the nearest point of an obstacle. A weighted objective function is used in the optimization problem. Equality and inequality constraints are taken to secure the UGV's dynamics and safety. The weighting factors are controlled by a fuzzy controller which is constructed by a fuzzy rule set and membership functions. Simulations are performed for two cases. First the weighting factors are considered as constant values to understand the characteristics of the corresponding solutions and then as variables that are adjusted by the fuzzy controller. The results are satisfactory for realistic situations considered. The proposed optimal path generation with the fuzzy control is expected to be well applicable to real environment.

• 한국지역지리학회지
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• 제22권1호
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• pp.25-35
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• 2016

본 연구는 영남지역 내 하위지역들을 구분하고 그 핵심부를 파악함으로써, 영남지역에 내재된 문화적 특성을 밝히는 기반을 제공하고자 하였다. 지역의 인문환경 요소인 행정구역과 방언, 그리고 자연환경 요소인 하천유역과 기후 분포를 중첩하고, 계수관과 유사한 환경요소를 갖는 범위를 하위지역으로 설정하였다. 요소들의 조합이 동일하게 나타나는 구획은 1개의 시 군으로 이루어진 것에서부터 6개의 시 군으로 이루어진 것에 이르기까지 모두 27개의 구획으로 구분되었다. 이들은 안동, 상주, 경주, 대구, 김해, 진주 증 6개의 하위지역으로 구분되었다. 각 하위지역은 유통에 장애가 되는 산줄기나 하천을 경계로 하며, 장애가 뚜렷하지 않은 경우에는 점이지대가 나타났다. 안동하위지역은 봉화와 예천, 영주, 의성, 군위, 영양, 청송, 영덕, 울진 등으로 이루어져 있으며, 상주하위지역은 상주와 구미, 김천, 문경을 포함한다. 경주하위지역은 경주와 영천, 포항 등을 포함하고, 대구하위지역은 대구와 칠곡, 고령, 성주, 경산, 청도 등으로 이루어져 있다. 김해하위지역은 김해와 양산, 부산, 울산, 창녕, 밀양 등을 포함하며, 진주하위지역은 진주와 합천, 의령, 사천, 고성, 통영, 남해, 함안, 거창, 함양, 산청, 하동, 창원, 거제 등으로 이루어져 있다.