• 대한전기학회논문지:전력기술부문A
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• 제48권11호
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• pp.1374-1381
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• 1999

This paper describes development of a package for generator maintenance scheduling program with user-friendly interactive mode. Generator maintenance scheduling is to select desirable maintenance periods of generators in the given interval satisfying reliability or economic criteria. Window-based system for user-friendly mode and Oracle-based database system for efficient data management are established in our package. Reserve rate levelization and LOLP minimization are performed in calculation mode, which is composed of DLL programs. Many graphs and charts are illustrated for the user-analysis. Operation is carried out by day-based unit, not by week. The case study has been conducted with the data of practical KEPCO power system in 1999 and successfully demonstrated its effectiveness.

• 대한수학회지
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• 제58권1호
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• pp.109-122
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• 2021

In this paper, we consider the problem of finding the hypersurface Mn in the Euclidean (n + 1)-space ℝn+1 that satisfies an equation of mean curvature type, called singular minimal hypersurface equation. Such an equation physically characterizes the surfaces in the upper half-space ℝ+3 (u) with lowest gravity center, for a fixed unit vector u ∈ ℝ3. We first state that a singular minimal cylinder Mn in ℝn+1 is either a hyperplane or a α-catenary cylinder. It is also shown that this result remains true when Mn is a translation hypersurface and u is a horizantal vector. As a further application, we prove that a singular minimal translation graph in ℝ3 of the form z = f(x) + g(y + cx), c ∈ ℝ - {0}, with respect to a certain horizantal vector u is either a plane or a α-catenary cylinder.

• KIEAE Journal
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• 제15권2호
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• pp.19-26
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• 2015

Purpose: Maximizing human comfort in design of medical environments depends immensely on specialized architects particularly critical care design; the study proposes Evidence-Based Design as an apparent analog to Evidence-Based Medicine. Healthcare facility designs are substantially based on the findings of study in an effort to design environments that augment care by improving patient safety and being therapeutic. On SPSS (Statistical Package for Social Science) t-test is applied to simulate two independent variables of PDR (Pre Design-Research) and POE (Post- Occupancy Evaluation). PDR is conducted on relatively new hospital Hallym University Dongtan Sacred Heart Hospital to analyse visibility from researchers' point of view, here the ICU is arranged in I-Shape. POE is applied on Dongguk University Ilsan Hospital to simulate walking on LogWare where two NS are designed based on L- Shape and Seoul St. Mary's Hospital, The Catholic University of Korea where five NS are functional for ICU Intensive Care Unit, Surgical Intensive Care Unit (SICU), Medical Intensive Care Unit (MICU), Critical Care Unit (CCU), Korean Oriental Medical Care Unit which are mostly arranged in U-Shape, and walking pattern is recognized to be in a zigzag path. Method: T-Test is applied on two dependent communication variables: walkability and visibility, with confidence interval of 95%. This study systematically analyses the Nurse Station (NS) typo-morphology, and simulates nurse horizontal circulation, by computing round route visits to patient's bed, then estimating minimum round route on LogWare stop sequence software. The visual connectivity is measured on depth map graphs. Hence the aim is to reduce staff stress and fatigue for better patients care by minimizing staff horizontal travel time and to facilitate nurse walk path and support space distribution by increasing effectiveness in delivering care. Result: Applying visibility graph and isovist field on space syntax on I- Shape, L- Shape and U- Shape ICU (SICU, MICU and CCU) configuration, I-shape facilitated 20% more patients in linear view as they stir to rise from their beds from nurse station compared to U-shape. In conclusion, it was proved that U-Shape supply minimum walking and maximum visibility; and L shape provides just visibility as the nurse is at pivot. I shape provides panoramic view from the Nurse Station but very rigorous walking.

• 한국가정과교육학회지
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• 제32권3호
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• pp.161-177
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• 2020

본 연구는 2015 개정 중학교 가정 교과서의 '청소년기의 소비생활' 단원을 지속가능한 발전(ESD)의 측면에서 분석해 ESD와의 연관성을 찾고, Romey 분석을 통해 '청소년기의 소비생활' 단원의 탐구 성향을 분석하였다. 이를 위해 먼저 선행연구에서 사용된 ESD와 관련된 평가 기준을 정리하여 환경적 관점(천연자원, 기후변화/재해예방 및 완화, 지속가능한 농촌과 도시), 경제적 관점(기업의 지속가능성, 시장경제, 빈부격차 완화), 사회·문화적 관점(인권/평화/인간보호, 문화적 다양성과 이해, 건강/안전, 시민참여, 국가경영)으로 11개의 핵심 내용을 가진 분석틀을 설정하였다. 설정한 분석틀을 바탕으로 중학교 가정 교과서 12종의 '청소년기의 소비생활' 단원의 학습 내용을 분석하였고, Romey의 탐구적 교과서 분석방법에 따라 본문문장, 사진·삽화·표·그래프, 활동과제를 분석하였다. 분석결과 경제적 관점의 '시장경제', '국가경영'의 핵심 요소를 모든 교과서가 본문문장, 사진·삽화·표·그래프, 활동과제의 3가지 형태로 다양하게 제시하고 있었으나, 건강/안전, 시민참여, 지속가능한 농촌과 도시, 기업의 지속가능성 핵심 내용의 내용 요소는 상대적으로 부족해 ESD의 다양한 내용을 다루는 교과서 개발이 필요한 것으로 보았다. 또한 Romey 분석 결과 대부분의 교과서에서 본문문장, 사진·삽화·표·그래프는 권위적 성향으로, 활동과제의 경우 탐구적 성향으로 나타났다. 청소년들의 지속가능한 발전을 위한 소비 가치관 형성과 행동 실천을 위해 보다 다양한 ESD 관련 내용을 가정과 수업에 반영하고, 탐구적 성향의 학습활동을 수업에 창의적으로 활용할 필요가 있다. 또한 가정과 ESD 수업 모델을 개발해 가정과 교육 현장에서 실천하여 효과를 살펴볼 필요가 있을 것이다.

• 한국환경교육학회지:환경교육
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• 제11권2호
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• pp.156-176
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• 1998

On the border between the Geography subject and the Science subject, much of the content area is found to be interrelated or shared in common due to the characteristics of each subject. This possibly causes a problem of which of the two subjects should treat these overlapping areas with more responsibility and importance, and, as a result, might cause teachers to neglect the areas and result in insufficient treatment of the areas on both sides. In other words, these overlapping area can be overlooked on both subjects. On the other hand, as the science subject treats these areas more deeply and widely in both quantity and quality, the geography subject might lose its original content area to the science subject and accordingly lose its characteristics as an independent subject. To conclude, the following suggestions must be taken into consideration when we develop and organize the environment-related unit in the geography subject. First, the various real cases damaged by pollution, the efforts and steps to avoid being polluted, the inquiry questions and activities to set up the value of the environment conservation, and sufficient assistant materials such as maps, graphs, photos, illustrations, statistics, which will help to realize the environment problem more directly and clearly, must be presented in the textbooks. Second, as the environment education is not just teaching the environmental pollution, the content should be composed for the students to realize the value of the environment and to change their awareness and attitude toward the environment. Third, the environment education cannot be restricted to a certain subject, or it needs to be approached in multi-subject areas. To exercise a effective environment education while we maintain the unique characteristics of the geography subject, a way to link the environment and the region, which is one of the main concepts of geography, should be developed. Finally, textbooks are indispensible materials to teaching-learning, but for more effective teaching the teachers of geography should try to recompose and reorganize the content and to develop newer and more effective teaching material-aids.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.101-105
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• 1999

ETC(Electronic Toll Collection)는 고속도로 등의 자동요금징수시스템으로 노변장치(Beacon)와 차량 탑재장치(On Boa.4 Unit) 사이에 통신이 가능하다. 본 연구에서는 상호 통신의 마이크로파 전파 경로를 모델화하여 전파 다중 경로에 의한 수신전압의 페이딩 효과를 분석하였다. 전파 모델에서는 환경 변화, 편파, 및 안테나 방사패턴 둥의 영향들을 고려하였다. 또한 페이딩 효과를 줄이기 위하여 공간 다이버시티 기술도 제안하였다. 분석결과, 강우 시 반사면의 반사계수가 변화하여 수직 편파의 경우 페이딩 효과가 크게 감소하였다 또한 원형 편파의 경우 일반적으로 페이딩 효과가 적었으며 높은 방향성을 가진 안테나를 사용하면 페이딩 효과가 감소하였다. 노변장치에서 공간 다이버시티 기술로 두 개의 안테나들로 신호를 보내면 차량과의 거리가 증가할수록 페이딩 효과를 감소시킬 수 있었다. 이러한 결과들을 차량 탑재 장치에서 수신된 전압의 크기(dB)와 노변장치와 차량 사이 거리로 도시하였다.

• 정보보호학회논문지
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• 제32권3호
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• pp.527-545
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• 2022

본 연구에서는 조직화된 공격 주체가 수행하는 APT 공격을 효과적으로 탐지하기 위하여, 공격체인을 구성하여 공격을 탐지하는 시스템을 구축하였다. 공격체인 기반 APT 공격 탐지 시스템은 다양한 호스트 및 네트워크 모니터링 도구에서 생성하는 이벤트를 수집하고 저장하는 '이벤트 수집 및 저장부', 이벤트로부터 MITRE ATT&CK^®에 정의된 공격기술 수준의 단위공격을 탐지하는 '단위공격 탐지부', 단위공격으로 생성된 이벤트로부터 Provenance Graph 기반의 인과관계 분석을 수행하여 공격체인을 구성하는 '공격체인 구성부'로 구성하였다. 시스템을 검증하기 위하여 테스트베드를 구축하고 MITRE ATT&CK Evaluation 프로그램에서 제공하는 모의공격 시나리오를 수행하였다. 실험 결과 모의공격 시나리오에 대해 공격체인이 효과적으로 구성되는 것을 확인하였다. 본 연구에서 구현한 시스템을 이용하면, 공격을 단편적인 부분으로 이해하기보다 공격의 진행 흐름 관점에서 이해하고 대응할 수 있을 것이다.

• 대한가정학회지
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• 제46권2호
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• pp.137-153
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• 2008

This research analyzed the contents of the elementary and middle school home economics textbooks within the 7th Curriculum from two theoretical Perspectives: structural functionalism and healthy family. A quantitative and in-depth content analysis was carried out with the five elements of family structure, family role, family relation, communication, dating and pregnancy. A healthy family Perspective was found in relation to the elements of family type and family role from the in-depth analysis of the elementary school practical arts textbook. In the middle school textbooks, the five elements reflected a strong structural-functionalist tendency. In both levels, the quantitative content analysis indicated that a structural-functionalist viewpoint was prevalent in the graphical components of the textbooks, including pictures, diagrams and graphs.

• Structural Engineering and Mechanics
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• 제61권3호
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• pp.359-370
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• 2017

This study presents a particle swarm optimization algorithm integrated with weighted particle concept and improved fly-back technique. The rationale behind this integration is to utilize the affirmative properties of these new terms to improve the search capability of the standard particle swarm optimizer. Improved fly-back technique introduced in this study can be a proper alternative for widely used penalty functions to handle existing constraints. This technique emphasizes the role of the weighted particle on escaping from trapping into local optimum(s) by utilizing a recursive procedure. On the other hand, it guaranties the feasibility of the final solution by rejecting infeasible solutions throughout the optimization process. Additionally, in contrast with penalty method, the improved fly-back technique does not contain any adjustable terms, thus it does not inflict any extra ad hoc parameters to the main optimizer algorithm. The improved fly-back approach, as independent unit, can easily be integrated with other optimizers to handle the constraints. Consequently, to evaluate the performance of the proposed method on solving the truss weight minimization problems with discrete variables, several benchmark examples taken from the technical literature are examined using the presented method. The results obtained are comparatively reported through proper graphs and tables. Based on the results acquired in this study, it can be stated that the proposed method (integrated particle swarm optimizer, iPSO) is competitive with other metaheuristic algorithms in solving this class of truss optimization problems.

• Advances in aircraft and spacecraft science
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• 제6권6호
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• pp.479-495
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• 2019

Periodic cellular core structures included in sandwich panels possess good stiffness while saving weight and only lately their potential to act as passive vibration filters is increasingly being studied. Classical homogeneous honeycombs show poor vibracoustic performance and only by varying certain geometrical features, a shift and/or variation in bandgap frequency range occurs. This work aims to investigate the vibration filtering properties of the AUXHEX "hybrid" core, which is a cellular structure containing cells of different shapes. Numerical simulations are carried out using two different approaches. The first technique used is the harmonic analysis with commercially available software, and the second one, which has been proved to be computationally more efficient, consists in the Wave Finite Element Method (WFEM), which still makes use of finite elements (FEM) packages, but instead of working with large models, it exploits the periodicity of the structure by analysing only the unit cell, thanks to the Floquet-Bloch theorem. Both techniques allow to produce graphs such as frequency response plots (FRF's) and dispersion curves, which are powerful tools used to identify the spectral bandgap signature of the considered structure. The hybrid cellular core pattern AUXHEX is analysed and results are discussed, focusing the investigation on the possible spectral bandgap signature heritage that a hybrid core experiences from their "parents" homogeneous cell cores.