• 사회복지연구
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• 제41권4호
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• pp.107-133
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• 2010

본 연구는 한국사회에 확산되는 기러기 가족의 구성원으로서 기러기 아빠의 분거가족경험을 총체적으로 이해하기 위해 7명의 기러기 아빠를 대상으로 심층 인터뷰한 후 질적연구 방법을 활용하여 분거가족 경험의 일반적 구조를 파악하였다. 연구 결과, 기러기 아빠의 분거가족경험은 전후 맥락과 시간성을 고려하여 가족분거 결정단계와 초기단계, 유지단계로 구분되었고 5개의 상위 구성요소가 도출되었다. 먼저, 가족분거 결정단계는 "조기유학의 내·외적 필요" 로 나타났고, 가족분거 초기단계는 "가족이탈의 해방과 결핍" 으로 도출되었으며 가족분거 유지단계는 "고갈된 독거인의 삶", "가족없는 공간을 채움", "분거기간의 장기화: 와도 걱정, 안와도 걱정" 으로 나타났다. 이와 같은 연구결과에 근거하여 가족분거를 경험한 기러기아빠에 대한 실천적 함의를 제시하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.312-315
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• 2007

본 연구는 공공시설과 교육시설을 대상으로 시설관리자의 효율적인 유지관리 업무수행과 유지관리 주체 간의 원활한 정보교환을 위한 웹기반 건축물 유지관리 이력정보관리 시스템 개발을 목적으로 한다. 시설 노후화와 성능판단의 근거로 활용할 수 있는 유지관리 이력정보 관리과정상 발생하는 문제점을 인식하고 각 시설의 시설관리 담당자 면담조사를 통하여 시설별 유지관리 이력관리 현황을 분석하여 이를 근거로 통합 유지관리 업무프로세스를 도출하였다. 또한 시설관리 전문가 집단의 요구사항을 수렴하여 공공시설과 교육시설의 특성을 반영한 유지관리 업무 수행 효율화를 극대화와 현장실무적용, 유지관리 이력DB의 활용을 유도할 수 있는 건축물 유지관리 이력정보관리 시스템을 제안한다.

• 한국안전학회지
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• 제38권2호
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• pp.104-111
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• 2023

Rolling stock maintenance, which focuses on preventive maintenance, is typically implemented considering the potential harm that may be inflicted to passengers in the event of failure. The cost of preventive maintenance throughout the life cycle of a rolling stock is 60%-75% of the initial purchase cost. Therefore, ensuring stability and reducing maintenance costs are essential in terms of economy. In particular, private railroad operators must reduce government support budget by effectively utilizing railroad resources and reducing maintenance costs. Accordingly, this study analyzes the reliability characteristics of components using field data. Moreover, it resolves the problem of determining an economical replacement interval considering the timing of scrapping railroad vehicles. The procedure for determining the optimal replacement interval involves five steps. According to the decision model, the optimal replacement interval for the onboard signal device components of the "A" line train is calculated using field data, such as failure data, preventive maintenance cost, and failure maintenance cost. The field data analysis indicates that the mileage meter is 9 years, which is less than the designed durability of 15 years. Furthermore, a life cycle in which the phase signal has few failures is found to be the same as the actual durability of 15 years.

• 한국건축시공학회지
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• 제21권6호
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• pp.653-664
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• 2021

최근 에너지절약형 친환경주택의 건설기준 강화에 따라 고효율 주택의 수요가 증가하며, 창호공사의 비중이 함께 증가하고 있다. 창호는 사용빈도가 높고, 시공 시 특성에 따라 많은 하자가 발생할 가능성이 존재한다. 정부 기관이 공공임대주택에서 발생한 하자 민원을 조사한 바에 따르면, 접수된 민원 중 창호공사의 하자가 가장 높은 비중을 차지하고 있었다. 이에 따라 관련 선행연구를 고찰해보았고, 국내의 기존연구들은 창호공사의 시공 특성과 유지관리의 중요성을 반영한 연구가 부족한 실정이었다. 또한, 기존의 국외 연구들은 비용적 측면을 함께 고려해 시공자와 거주자의 입장을 모두 고려하였으며, 하자와 원인의 관계를 구조화하기 위한 움직임을 보여주었다. 따라서 본 연구는 창호공사의 시공단계에서 발생하는 원인을 분석해 시공 특성을 반영하고, 하자 보수 후 재발생 가능성에 기초한 유지관리의 중요성을 함께 고려해 중점관리요소를 도출할 것이다. 또한, 궁극적으로 하자 유형과 원인의 인과관계를 분석해 직관적 판단이 가능한 하자 유형별 중점관리요소를 선정함으로써 실효성 높은 하자관리 방안을 제시해 시공단계 하자를 예방하고 유지관리 비용을 저감하는 데 기여할 것이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1158-1164
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• 2007

Recently, the demand on the practical application of life-cycle cost effectiveness for design and rehabilitation of civil infrastructure is rapidly growing unprecedentedly in civil engineering practice. Accordingly, it is expected that the life-cycle cost in the 21st century will become a new paradigm for all engineering decision problems in practice. However, in spite of impressive progress in the researches on the LCC, so far, most researches in Koreahave only focused on roadway bridges, which are not applicable to railway bridges. Thus, this paper presents the formulation models and methods for uncertainty-based LCCA for railroad bridges consideringboth objective statistical data available in the agency database of railroad bridges management and subjective data obtained form interviews with experts of the railway agency, which are used to anew uncertainty-based expected maintenance/repair costs including lifetime indirect costs. For reliable assessment of the life-cycle maintenance/repair costs, statistical analysis considering maintenance history data and survey data including the subjective judgments of railway experts on maintenance/management of railroad bridges, are performed to categorize critical maintenance items and associated expected costs and uncertainty-based deterioration models are developed. Finally, the formulation for simulation-based LCC analysis of railway bridges with uncertainty-based deterioration models are applied to the design-decision problem, which is to select an optimal bridge type having minimum Life-Cycle cost among various railway bridges types such as steel plate girder bridge, and prestressed concrete girder bridge in the basic design phase.

• Journal of Animal Science and Technology
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• 제60권4호
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• pp.7.1-7.5
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• 2018

Background: Mice are widely accepted research models of great clinical significance. Maintenance of laboratory mice breed is an essential aspect for performing research activities in various fields of science. Infanticide is one of the prominent causes of litter loss during maintenance of laboratory mice stock. The present study is an effort to monitor the effect of change in ambient temperature of female mice below the normal range on cannibalism and infanticide during early postparturition phase. Adult female Swiss albino mice have been divided into two groups of control and treatment. On the day of litter group one was maintained under controlled temperature conditions (minimum $20^{\circ}C$ to maximum $23^{\circ}C$) throughout, while female mice belong to group two have been exposed to variation of room temperature (maximum $15^{\circ}C$ to minimum $10^{\circ}C$ for two nights and one day) until 36 h postparturition. Results: The effects of temperature changes were observed on the infanticide behaviour of dams along with the survival of pups in early postparturition phase till 36 h after delivery. The significant statistical difference (P < 0.05) was reported in infanticide behaviour of dams when control and treatment group was compared. It is observed that decrement in surrounding temperature promotes decrement in the ambient body temperature of dams during early postparturition. It is proposed that alteration of hypothalamic homeostasis due to temperature change induces cannibalism and infanticide behaviour. Lack of thermoregulation during early postparturition creates the sense of insecurity, in-satiety, anxiety and stress. Conclusions: Authors strongly recommend the maintenance of body and surrounding temperature to prevent infanticidal behaviour and cannibalism within Swiss albino mice population. Further investigations are advisable to authenticate the active behavioural and biochemical pathway behind the phenomena.

• 디지털융복합연구
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• 제8권1호
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• pp.1-10
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• 2010

2004년부터 정부는 기존 산업의 고도화를 위해 RFID/USN활용 지원사업을 단계적으로 추진해 왔다. 최근들어 일부 대기업을 중심으로 RFID/USN활용 성과들이 확인되고 있으나, 추가적인 산업정책 및 지원을 위한 기본적인 정책 자료가 부족한 실정이다. 이에 2008년도 시행된 27개의 시범사업을 대상으로 실 수혜기관의 만족도를 조사하여 RFID/USN의 구축단계, 활용단계(기술적 품질), 활용단계(업무적 품질), 그리고 유지보수단계 등 4단계에서의 만족도를 평가하고, 시사점을 도출하고자 하였다. 연구 결과, RFID/USN 기술의 안정성은 상당한 수준에 도달하였으나. 활용 및 확산을 위한 유지보수단계의 만족도가 가장 낮게 나타났다. 정책적 시사점으로 태그 및 기기의 저렴한 제공, 서비스 신뢰성 및 지속성을 위한 유지보수 컨소시엄 구성, RFID/USN 활용을 위한 수혜기업의 내부역량 강화 등 RFID/USN 유지보수 단계의 구체적인 정책지원등을 제시하였다.

• Journal of Positioning, Navigation, and Timing
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• 제12권1호
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• pp.83-89
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• 2023

The Korea Augmentation Satellite System (KASS) system is a Satellite Based Augmentation System (SBAS) under development to provide APV-I SBAS service in the Republic of Korea. The KASS ground segment generates correction and integrity information for GPS measurements of KASS users using the accurate positions of KASS Reference Station (KRS) antenna phase centers. For this reason, the accuracy of KRS reference points through geodetic survey campaigns is one of the important factors for providing the KASS service in compliance with the required navigation performance. In order to obtain accurate positions, two geodetic survey campaigns were performed at several reference points, such as Mark, Center of Mast at Ground Level (CMGL), and Center of Hole in Top Plate (CHTP), of each KRS site using three different survey methods, the Virtual Reference Station (VRS), Flächen Korrektur Parameter (FKP), and raw data post-processing methods. By comparing and analyzing the results, the computed coordinates of the reference points were verified and Antenna Phase Center (APC) positions were calculated using KRS Antenna Reference Point (ARP) data, and the first KASS Site Acceptance Test (SAT#1) was performed successfully using the verified APC coordinates. After the first site survey activities, the KASS operators should maintain the coordinates with the required performance such that the overall KASS navigation performance commitment is guaranteed during the lifetime of 15 years. Therefore, the maintenance plan for the KRS antenna coordinates should be developed before the commissioning of KASS operation planned after 2023. Therefore, this paper presents a geodetic survey method selected for the maintenance activities and provides the rationale for using this method.

• Structural Monitoring and Maintenance
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• 제3권4호
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• pp.335-347
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• 2016

One of major errors in flow rate measurement for two-phase flow using an Electrical Capacitance Sensor (ECS) concerns sensor sensitivity under temperature raise. The thermal effect on electrical capacitance sensor (ECS) system for air-water two-phase flow monitoring include sensor sensitivity, capacitance measurements, capacitance change and node potential distribution is reported in this paper. The rules of 12-electrode sensor parameters such as capacitance, capacitance change, and change rate of capacitance and sensitivity map the basis of Air-water two-phase flow permittivity distribution and temperature raise are discussed by ANSYS and MATLAB, which are combined to simulate sensor characteristic. The cross-sectional void fraction as a function of temperature is determined from the scripting capabilities in ANSYS simulation. The results show that the temperature raise had a detrimental effect on the electrodes sensitivity and sensitive domain of electrodes. The FE results are in excellent agreement with an experimental result available in the literature, thus validating the accuracy and reliability of the proposed flow rate measurement system.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.139-141
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• 2013

Construction industry has been participated in the effort for the reduction of environmental pollution such as introduction of green building certification, enactment of environment related regulation. However these efforts are focused on the design and maintenance phases of entire life cycle, construction phase that can occur intensive environmental impact in a short period is insufficient. Therefore this study aim to derive environmental management factors in construction phase and assess them using reliability analysis and factor analysis. As a results, the 20 factors was classified into 4 superordinate such as 'plan and supervision', 'environmental factor management', 'licensing management', 'surrounding environment management'.Based on result of this study, further study should be developed the checklist for effective environmental management in construction phase.