• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.604-605
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• 2015

To secure quality of dam construction needs appropriate construction duration. Tight construction schedule may have negative influence on infrastructure quality, work safety and maintenance cost. It is necessary to reflect proper construction duration in the planning phase. There have been standards for estimating construction duration of building and industrial complex development but dam construction have not. In order to estimate construction duration of CFRD, feasible study reports and design reports were analyzed to acquire available information. After that, considering on construction duration methods such as comparison with similar cases, approximate estimating formula, approximate quantity assumption were adapted to Critical Path items. Hence, this study present framework for construction duration estimating of CFRD in the planning phase. This framework can be applied other types of dam along the same line.

• 대한공간정보학회지
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• 제13권1호
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• pp.89-96
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• 2005

최근 도로 및 지하시설물 관련 GIS시스템 구축이 각 지방자치단체들에서 하나, 둘씩 완료되어감에 따라 해당 지방자치단체들의 관심은 기존의 GIS시스템 구축으로부터 이제 1차 완료된 GIS시스템의 유지관리로 서서히 변화되고 있다. 이와 같은 현상은 시간이 지날수록 더욱 증대할 것이며 따라서 해당 지방자치단체들은 기 구축된 GIS시스템을 유지관리하기 위한 여러 관점에서의 지침 및 지원이 필요한 시점이다. GIS시스템의 유지관리란 주제는 그 영역이 상당히 광범위하고 그 시기적인 필요성 또한 일부 앞서 GIS시스템을 구축한 지방자치단체들로부터 크게 공감되고 있는 것으로 조사되었다. 그럼에도 불구하고 현재까지 GIS시스템의 유지관리와 관련되어 체계적으로 수행된 연구는 양적으로나 질적으로 매우 미비한 상황으로 파악되었으며 이에 본 연구는 GIS시스템 유지관리란 주제를 체계적으로 접근하기 위한 시도의 일환으로 그중 가장 근본적인 요소라고 판단되는 GIS데이터 유지관리의 차원에서 우선 접근하고자 시도되었다. 이를 위해 조사된 지방자치단체들의 GIS시스템 유지관리 관련 현황이 체계적으로 정리되었고 이를 분석하여 GIS데이터 관련 문제점 유형 및 지방자치단체의 해결발안을 도출하였다. GIS데이터는 기본도와 지하 시설물도로 나누어 각각 접근 및 분석되어 지방자치단체를 위한 효율적인 GIS데이터 유지관리방안을 제시하였다.

• 한국전문물리치료학회지
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• 제3권3호
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• pp.32-43
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• 1996

The purpose of this case study was to introduce functional electrical stimulation(FES) for paraplegic patients. FES provides the ability to rise from sitting to standing, maintenance of a standing position, and the ability to walk with a reciprocal gait. Six channels of electrical stimulation are sufficient for synthesis of a simple reciprocal gait pattern in these patients. During the double-stance phase, knee extensor muscles of both knees are stimulated, providing sufficient support for the body. Only one knee extensor muscle group is excited during the single-stance phase. The swing phase of the contralateral lower extremity is accomplished by eliciting the synergic flexor muscle response through electrical stimulation of afferent nerves. The transition from the double-stance phase to the swing phase is controlled by two hand switches used by the therapist or built into the handles of the walking frame for using by the patient. A twenty-five years old male was with a T9/T9 spinal cord injury due to a traffic accident and admitted to Yonsei Rehabilitation Hospital for comprehensive treatment. After 30 days of training using the Parastep(R) he was able to stand for 10 minutes. After 43 days, he was able to walk and at discharged he could walk for 100 meters.

• 한국BIM학회 논문집
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• 제5권4호
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• pp.1-10
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• 2015

In order to apply the BIM technology effectively and efficiently during the life-cycle of project, it is important to deliver a accurate information on BIM from designer, and it should be used effectively at construction or maintenance stage. However, stakeholders have created a new BIM model at each phase in many practise adopting BIM, not used BIM generated in design stage. Because they have different purposes for using BIM, and deliver the BIM model without the sufficient explanation or application. It is necessary to define the range of usable BIM in construction phase with analyzing clearly the BIM created in design phase, and determining the difference with required BIM in construction phase. Therefore, this study propose a method for construction c

• 대한토목학회논문집
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• 제31권2D호
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• pp.255-266
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• 2011

제품의 제조, 사용, 폐기 등 전과정에서 발생되는 환경부하를 평가하기 위해 국제표준화기구(ISO)에서 채택한 전과정평가(LCA)는 개별 제품뿐만 아니라 건축물이나 사회기반시설과 같은 복잡한 시스템으로 광범위하게 적용되고 있다. 하수처리수 재이용시설에 LCA를 도입하는 것은 수질오염물질의 처리뿐만 아니라 이와 관련한 다른 여러 활동의 상호 작용을 포함한 전체적인 시스템을 파악할 수 있게 된다. 본 연구는 전과정 평가기법을 적용하여 하수처리수 재이용시설에 대한 전과정 영향평가를 수행하였다. 전과정 영향평가의 결과, 수계생태독성이 88.3%로 가장 큰 환경부하를 가지는 것으로 나타났으며, 전과정에서 가장 큰 영향을 미치는 단계는 운영 및 유지관리단계로 나타났다. 본 연구의 결과는 종합적인 환경부하를 정량화함으로서 환경정책 수립자에게 환경 개선의 기회를 규명할 수 있는 정보를 제공해 줄 수 있으며, 건설 초기단계에서 친환경적인 설계를 위한 의사결정시 판단자료로 활용할 수 있을 것이다.

• 한국구조물진단유지관리공학회 논문집
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• 제14권1호
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• pp.165-174
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• 2010

본 논문에서는 실물 콘크리트 거더 교량의 가속도 응답 신호를 이용하여 구조물의 상태변화를 경보한 후 그 위치 변화를 검색하는 2단계 구조건전성 모니터링 체계를 제시하였다. 먼저, 2경간 연속 콘크리트 거더 교량인 미호천교를 대상교량으로 선정하였으며, 볼링공을 이용한 강제진동 실험으로부터 동특성을 추출하였다. 다음으로, 미호천교의 2단계 구조건전성 모니터링 체계 구축을 위한 손상 발생 경보 및 손상 위치 검색 기법들을 선정하였다. 손상 경보 기법으로는 시간영역 특징을 이용하는 자기회귀모델과 주파수응답함수의 상관계수, 주파수응답비보증지수를 선정하였다. 손상 위치 검색 기법으로는 모드변형에너지기반 손상지수법을 선정하였다. 마지막으로, 덤프트럭을 이용한 정적 재하 실험을 통해 2단계 손상 모니터링 체계의 적합성을 검증하였다.

• 설비공학논문집
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• 제24권1호
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• pp.70-76
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• 2012

The purpose of this study is to analyze of the operating characteristics of the Gas engine driven Heat Pump(GHP) and to reduce maintenance costs through the most Economical plan. As the zoning modifications that have economic effects were confirmed. Applications should be made with a similar purpose of the space. The combination of a modified space has led to reduced operating hours of the outdoor unit. The reduction of the outdoor unit operating hours, reducing maintenance costs accordingly. When analyzed at six years have elapsed, the amount of savings through zoning modifications is more than an additional construction cost. During the design phase, cost-effective operation of the GHP is required for the proper zoning plan.

• 한국CDE학회논문집
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• 제21권2호
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• pp.111-121
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• 2016

The plant equipment usually has a long life cycle. During its O&M (Operation & Maintenance) phase, since the occurrence of an accident of offshore plant equipment causes catastrophic damage, it is necessary to make more efforts for managing critical offshore equipment. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the health status data of important offshore equipment and their environment data, which leads to much concern on CBM (Condition-Based Maintenance). In this study, we will propose an approach to estimate the remaining lifetime of an offshore plant equipment (pump tower) based on gathered ocean environment data.

• The Journal of Advanced Prosthodontics
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• 제12권1호
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• pp.15-21
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• 2020

PURPOSE. The aim of the current study was to analyze treatment concepts of a cohort of German dentists for planning, fabrication, and maintenance of implant-supported fixed and removable restorations. MATERIALS AND METHODS. A questionnaire including queries about experiences with implant-supported restorations as well as prosthetic and maintenance treatment concepts for supplying patients with fixed and removable implant-supported prosthetic restorations was developed and sent to 350 dental offices registered in the municipal area of Leipzig, Germany. RESULTS. An overall total of 62 returned questionnaires were included in the analyses, which relates to a response rate of 17.7%. Participating dentists were more involved in the prosthetic aspects of implant dentistry rather than surgery, while prosthetic concepts such as backward planning, digital processing, and application of all-ceramic materials were not commonly performed. Simple attachments were preferred over complex retention systems in removable implant-supported restorations. Tooth/implant-supported fixed denture prostheses as well as removable denture prostheses with supporting posterior implants were not regarded as a favorable treatment option. CONCLUSION. Within the limitations of the study, the data indicate that dentists favor simple and conventional treatment approaches in implant prosthetics. Prosthetic aspects in the planning of implant-supported restorations are often neglected. Prosthetic treatment guidelines and aspects should commonly be considered in the planning phase of implant-supported prosthetic restorations, and awareness should be increased in postgraduate education.

• Journal of Power Electronics
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• 제18권5호
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• pp.1347-1356
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• 2018

In a three-phase system, three-phase AC signals can be translated into two-phase DC signals through a coordinate transformation. Thus, the PI regulator can realize a zero steady-state error for the DC signals. In the control of a three-phase grid-connected inverter, the phase angle of grid is normally detected by a phase-locked loop (PLL) and takes part in a coordinate transformation. A novel control strategy for a three-phase grid-connected inverter with a frequency-locked loop (FLL) based on coordinate transformation is proposed in this paper. The inverter is controlled as a current supply. The grid angle, which takes part in the coordinate transformation, is replaced by a periodic linear changing angle from $-{\pi}$ to ${\pi}$. The changing angle has the same frequency but a different phase than the grid angle. The frequency of the changing angle tracks the grid frequency by the negative feedback of the reactive power, which forms a FLL. The control strategy applies to non-ideal grids and it is a lot simpler than the control strategies with a PLL that are applied to non-ideal grids. The structure of the FLL is established. The principle and advantages of the proposed control strategy are discussed. The theoretical analysis is confirmed by experimental results.