• 한국구조물진단유지관리공학회 논문집
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• 제13권1호통권53호
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• pp.205-213
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• 2009

본 연구에서는 사장교의 케이블 장력을 장기적인 관점에서 보다 효과적으로 분석하고 모니터링할 수 있는 케이블 장력 모니터링 시스템을 개발하는 연구를 수행하였다. 제안된 모니터링 시스템에는 실시간 동적 데이터에서 일정 대상시간 동안의 가속도 데이터를 선정하고, 이를 고속 푸리에 변환 알고리즘에 적용하여 주파수 분석한 결과를 평균하여 일반화시키는 신호해석이론이 적용되었다. 제안된 케이블 장력의 모니터링 시스템의 적용성을 평가하기 위하여 실제 공용중인 사장교에 대한 현장재하시험을 실시하였다. 현장계측을 통한 수동으로 계산된 장력과 모니터링 시스템의 강제저장 기능을 통해 저장된 데이터를 수계산하여 반자동으로 계산된 장력을 비교한 결과, 장력차이가 1% 이내로 발생하였고, 제안된 모니터링 시스템에서 자동으로 계산된 장력을 비교한 결과에서는 약 5% 범위의 무시할만한 차이로 나타나 본 연구에서 제안된 사장교 케이블 장력 모니터링 시스템의 신뢰도를 검증하였다.

• 한국건설관리학회논문집
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• 제18권3호
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• pp.12-21
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• 2017

1960년대 이후 인구의 급격한 도시집중으로 인한 주택부족 문제를 해소하기 위해 정부에서는 공동주택을 대량으로 건설하였다. 하지만 이러한 주택정책은 공급에만 치우쳐져 공동주택의 노후화에 따른 유지관리 문제는 소홀하게 다루어져 왔다. 그러나 "도시 및 주거환경정비법"의 제정으로 재건축 허용 경과년수가 증가됨에 따라 공동주택의 유지보수가 중요하게 되었고, 주거공간으로서 기능을 유지하기 위해서는 공동주택의 장기적인 유지관리계획수립이 필요하게 되었다. 이에 따라 정부에서는 "주택법"을 통해 장기수선계획과 이를 위한 장기수선충당금의 적립을 의무화하였고, 이를 3년마다 조정하도록 의무규정을 두었다. 이에 따라 장기간의 수선비용을 계획하면, 계획기간 동안 동일한 비용을 적립하게 된다. 이는 형평성을 고려한 계획으로 보일 수 있지만, 화폐의 시간적 가치를 생각한다면, 초기시점에 입주한 입주자들이 후기시점에 입주한 입주자들에 비해 더 많은 금액을 납부하는 결과를 가져온다. 또한 계획한 수선비와 실제 수선비 사이에 차이가 발생할 경우 이를 반영하여 장기수선충당금 산정할 수 있는 기준이 부족한 상황이다. 이와 같은 장기수선계획으로 인하여, 수선비 부족은 적시에 유지보수가 이루어지지 못하여 향후 공동주택 노후화에 대응하기 어려우며, 과다한 장기수선비의 적립은 입주자들의 반발로 이어질 수 있다. 이에 본 연구에서는 장기수선계획 시 화폐의 시간적 가치를 고려함과 동시에 계획대비 실제 수선비용의 오차를 지속적으로 반영할 수 있는 장기수선충당금 산정 및 조정모델을 제시하였다. 이를 통해 보다 합리적이며 유연한 장기수선충당금 산출방안을 제시하여, 입주자들 간의 형평성을 도모하고, 향후 장기수선충당금의 불필요한 적립과 부족현상을 방지할 수 있을 것으로 기대된다.

• KIEAE Journal
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• 제15권6호
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• pp.63-68
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• 2015

Purpose: Most if buildings need various repair works for preventing or delaying the deterioration which gives rise to affect the living condition or function after constructed. Therefore, a long-term repair schedule should be planned and a repair cost is required. In this paper, it aimed at providing the statistical forecast model for a repair cost in roof water-proofing work and elevator work using statistical approach with three variables such as number of household, management area and a elapsed year. Data are collected in apartment housings which are located in Seoul area and conducted with interview and questionnaire sheet. Each analyzed work is divided into a partly work and fully work. Results of this study are shown that, first, the regression model takes a multiplying type like a Cobb-Douglas function and is changed into the log-linear type to include the three variable simultaneously. Second, the goodness-of-fit of the repair cost forecasting model has a good statistics in determinant's coefficient and Dubin-Watson value. Third, the management area is stronger factor than other the number of household and an elapsed year in roof water-proofing work and elevator work.

• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.737-744
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• 2008

Purpose: In advanced case of periodontitis, surgical treatment without bone contouring may result in residual pockets inaccessible to proper cleaning during post-treatment maintenance. This problem can be avoided or reduced by applying guided tissue regeneration. Materials and Methods: All of 3 patients had deep periodontal pocket depth and bleeding on probing, and radiograph revealed osseous defect, so we planned guided tissue regeneration using resorbable membrane with or without xenograft. Result: 6 months later, periodontal pocket depth and bleeding on probing was improved and gingiva was stable. Conclusion: Guided tissue regeneration using resorbable membrane with or without xenograft in osseous defect is predictable.

• 상하수도학회지
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• 제24권2호
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• pp.183-193
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• 2010

Well planned rehabilitation order of pipes is essential for efficient maintenance and management of Water Distribution Systems. In this study, not only deterioration rate of pipes but also structural and nonstructural failure which causes abnormal condition of WDS is considered to determine rehabilitation order. Probabilistic Neural Network is used for calculating deterioration rate at present and the importance of pipes is computed under structural and nonstructural failure by using Pipe by Pipe Failure Analysis and Effect Index. Utopian Approach, one of the Multi-Criteria Decision Making methods, is used for assessment of final rehabilitation order based on distance measure between utopian point and alternative one. Developed model in this study shows that it gives more reliable results than existing methods considering hydraulic relative importance does in application to real networks. In this point, the newly developed model, which gives advantages over existing models, can make a credible decision and simple application.

• 대한족부족관절학회지
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• 제12권1호
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• pp.9-13
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• 2008

Purpose: Medial capsulorrhaphy is additional hallux reduction method following various hallux reduction procedures and we are going to report author's opinion about several methods of medial capsulorrhaphy. Materials and Methods: We performed three kinds of medial capsulotomy and imbricatory capsulorrhaphy in hallux valgus surgery. Through 8 cadavar study, we compared the easiness of sesamoid reduction and hallux valgus angle reduction. Also, we measured thickness of capsule in various portions. Results: Longitudinal capsule incision and imbrication was useful in sesamoid reduction and vertical procedures was useful in hallux valgus angle reduction. The capsule thickness was measured thickest in dorsal and distal portioin. Conclusion: The methods of medial capsulorrhaphy should be planned preoperatively considering individual hallux deformities. These selected medial capsulorrhaphy can help the reduction of hallux valgus deformity correction and its maintenance.

• Journal of Electrical Engineering and Technology
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• 제7권5호
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• pp.772-777
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• 2012

Accidents caused by water absorption in water-cooled generator stator windings often occur all over the world. The absorption into the insulator of the coolant, which is used to cool down the heat generated by stator windings during operation, leads to the deterioration of dielectric strength, and insulation breakdown. An insulation breakdown may cause not only an enormous economic loss but also a very serious grid accident that would compromise stable supply of electric power. More than 50 % of domestic generators have been in operation for more than 15 years, and water absorption tests performed on 50 water-cooled generator stator windings during a five-year planned preventive maintenance period beginning in 2006 identified water absorption problems in 10 of them, all of which required repair. Because the existing water absorption test detects this problem by utilizing stochastic methods after measuring the capacitances at the final positions of insulation breakdown, its accuracy is limited. This study demonstrates that water absorption can be more accurately diagnosed by utilizing method along with a more precise one.

• 한국정보통신학회논문지
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• 제8권8호
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• pp.1632-1639
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• 2004

기존 이메일 프로그램은 비싼 통신요금과 저속의 위성통신환경에서 최대한 통신비를 줄이기 위한 목적으로 개발되었고, 그 결과 프로그램에 유연성이 떨어져, 새로운 기능의 추가나 업그레이드가 용이하지 않았다. 또한 기존 프로그램의 경우 이메일 전용으로서 다양한 육상과 해상간 업무용 프로그램과 연동시키는 데에 어려움이 많았으며, 개발자 입장에서도 무선위성통신의 특성상 개발이 쉽지 않았다. 따라서 본 논문에서는 기존 프로그램과는 달리 데이터를 패킷 분리하여 전송함으로써 프로토콜에 유연성을 주고, 실시간으로 여러 종류의 데이터를 전송할 수 있게 하여 동시에 E-mail뿐만 아니라, 모니터링 데이터, SMS, PMS를 위한 DB 데이터 등의 다양한 데이터를 전송할 수 있도록 구현하였다. 또한 프로그램 개발자들이 까다로운 위성통신환경을 몰라도 쉽게 개발할 수 있게 하고자, 컴포넌트를 윈도우즈 서비스 프로그램화 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.234-236
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• 2007

Even though the existing train route controlling method, using track circuits, ensures the sufficient number of operation, it still has problems such as discordance between train numbers which was planned for operating and train numbers being operated on the track, and allowing only one train entering for one route. To solve those problems, we study and develop the Smart train route controlling system which uses the real-time informations of train positions. This system enables improve the coefficient of utilization in a certain train route controlling section, and the safety level of train route controlling, but we should ensure satisfying reliability of data about tracks operated by trains. In addition, there is a need to protect accidents caused by erroneous information of train position, by reflecting changes of tracks, for example maintenance, improvement, expansion of tracks. In this paper, we describes data structure of a developed program which required to change CAD files to wiring diagrams and to generate them to data of tracks. And we show the result that the simulator, using the data structure, controls speed and route of trains without problems.

• Structural Engineering and Mechanics
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• 제35권1호
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• pp.37-52
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• 2010

Special-shape arch bridge for self-balance (SBSSAB) in Zhongshan City is a kind of new fashioned spatial combined arch bridge composed of inclined steel arch ribs, curved steel box girder and inclined suspenders, and the mechanical behavior of the SBSSAB is particularly complicated. The SBSSAB is aesthetic in appearance, and design of the SBSSAB is artful and particular. In order to roundly investigate the mechanical behavior of the SBSSAB, 3-D finite element models for spatial member and shell were established to analyze the mechanical properties of the SBSSAB using ANSYS. Finite element analyses were conducted under several main loading cases, moreover deformation and strain values for control section of the SBSSAB under several main loading cases were proposed. To ensure the safety and rationality for optimal design of the SBSSAB and also to verify the reliability of its design and calculation theories, the 1/10 scale model tests were carried out. The measured results include the load checking calculation, lane loading and crowd load, and dead load. A good agreement is achieved between the experimental and analytical results. Both experimental and analytical results have shown that the SBSSAB is in the elastic state under the planned test loads, which indicates that the SBSSAB has an adequate load-capacity. The calibrated finite-element model that reflects the as-built conditions can be used as a baseline for health monitoring and future maintenance of the SBSSAB.