• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.81-82
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• 2021

선박은 건조 후 선주에게 인도되기 전에 해상시운전을 하게 된다. 해상 시운전은 통상 안벽에서 수행 가능한 기기류를 테스트 한 후 해상에서 실시하는 것으로 메인 엔진의 출력, 발전기를 포함한 각종 보조기계의 작동상태, 선박의 조종성능과 속력 테스트, 항해 통신장비 테스트, 양묘기테스트 등이 있으며 이외에 선종에 따른 추가 테스트 또는 선주에 의하여 요구하는 특별한 테스트를 하기도 한다. 본 연구는 해상 시운전의 주요 테스트 내용 중 선박조종성능에 관하여 분석하고, 실제 선박을 운항하는 항해사에게 필요한 주요 정보를 식별하고자 하는 기초연구로 진행되었다.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.2
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• pp.44-50
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• 2004

Recently, as the number of entities participating in the Grid system increased, the response time of LDAP system became inadequate. Consequently, we have to design new LDAP that suitable for high performance Grid environments. For this, researches about analysis of performance LDAP system are needed firstly. However, because researches are focused mostly on read operation optimized environments, so these result of researches are not directly applied to high performance Grid environments that write operation occupies most. In this paper, we provide overall results of analysis of performance of distributed directory system. The analysis is based on an analytic performance model by applying the M/M/1 queuing model. Finally, based on the results, we suggest the direction for the design of high performance LDAP system and this research results can be applied as basic materials to design of GIS in high performance Grid environments as well as.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.14-24
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• 2000

In present research, the plywoods made of radiata pine or Japanese larch, the potential softwood species in mass supply, were discussed to examine their feasibility as the structural and concrete form panels through the basic properties test. First, plywood qualities and its nail performance were tested. The performance test for concrete form or structural panel by concentrated and uniformly distributed load were conducted to investigate the possibility as structural material for light frame and concrete constructions. Test results of basic quality such as specific gravity, cupping, bowing, and twisting appeared to satisfy the criteria for structural use. Also, nail performance test results, for roof and wall sheathing panels, nail lateral resistance, nail withdrawal resistance, and nail push head resistance proved to meet the required standard for structural use. The test results on performance as structural panel by concentrated and uniformly distributed load and as concrete form panel showed that these two species could be used for structural sheathing, subfloor, and concrete form panels.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.1
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• pp.39-58
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• 2004

It is very important that predict the inelastic seismic behavior exactly for seismic performance evaluation of a building in the performance based seismic design. Evaluation method of seismic performance based on the pushover analysis reflected in PBSE was developed by some researchers. For the evaluation of inelastic global and local seismic responses by pushover analysis exactly. lateral load distribution should be adjusted and reflected the dynamic characteristics of structural system and various seismic ground motions. And performance point should be determined based on the evaluation of reasonable deformation capacity of a building more exactly. An effective method based on the improved the adaptive lateral load distribution and the equivalent responses of a multistory building is proposed in this study to efficiently estimate the accurate inelastic seismic responses. The proposed method can be used to evaluate the seismic performance for the global inelastic behavior of a building and to accurately estimate its local inelastic seismic responses. In order to demonstrate the accuracy and validity of this method, inelastic seismic responses estimated by the proposed method are compared with those obtained from other analytical methods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.737-744
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• 2021

Spray paving minimizes material lost during the construction or repair of a road surface, and it can be done in conjunction with tack coating. This approach involves applying the asphalt mixture at the same time as spraying the tack coat by attaching a spraying device to the asphalt paver. When applying an asphalt overlay to an aged concrete surface, it is important to ensure the adhesion performance between different material properties. Accordingly, there is a need for a tack coat that can be applied by spray paving and that exhibits good adhesive performance on different materials. In this study, bonding strength tests under various conditions were performed to evaluate the basic performance of a tack coat developed for use with a spray paver. The bonding performance of the tack coat was observed to be affected by curing conditions and material lost during construction. The test results also showed that the tensile and shear bonding strengths of the developed tack coat were 1.21 and 1.99 times higher than those of a conventional one, respectively. As a result, the developed tack coat is considered suitable for application to spray paving.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.88.1-88.1
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• 2011

본 연구에서는 SOFC 시스템 설계기술 개발을 위한 기초 연구로서 전산해석을 이용한 SOFC 성능예측 기법을 개발하였다. 기본설계 단계에서 SOFC의 성능을 개략적으로 예측할 수 있는 1차원 예측 모델을 정립하였으며, 온도, 조성, 전해질, 전극 두께 등을 비롯한 다양한 조건 변화에 따른 성능예측을 수행하여 실험값과 비교한 결과 최대전력밀도 조건에서 23%의 오차를 갖는 것으로 나타났다. 또한 Stack 제작단계에서 다양한 운전조건과 형상변화에 따른 SOFC 성능 변화를 예측할 수 있는 3차원 해석기법을 정립하였으며, 최대전력밀도에서 5.1%의 오차를 보였다. 포괄적인 열 및 물질 전달 현상과 전기화학반응을 3차원적으로 해석함으로써 보다 정확한 예측이 가능하였다. 또한 수소와 적당량의 수분을 함께 공급할 경우 SOFC 성능이 향상되는 것으로 나타났다. 본 연구에서 개발된 기술을 활용할 경우 시제품 제작 전에 전지시스템의 성능을 미리 예측할 수 있으므로, 향후 제품 개발시 제작비용 절감과 설계기간 단축에 기여할 수 있을 것으로 기대된다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.39-43
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• 2000

본 논문에서는 IMT-2000 시스템에 대한 제안된 표준안을 기초로 송수신 시스템을 구성하여 광대역 무선채널 환경 및 다양한 시스템 운용환경에서 시스템의 성능을 분석한다. 수신 성능의 개선을 위하여 CCI(Co-Channel Interference) Canceller와 Rake 수신기를 혼합하여 기존의 Rake 수신기에서 제거할 수 없었던 자기 간섭(Auto Interference)을 제거하는 새로운 Rake수신기를 제안하였다. 또한 다중 경로 페이딩 모델로는 ITU-R M.1225에서 제시된 모델을 적용하였다. 성능 분석 결과, 상대적으로 작은 지연 확산을 가지는 채널 A가 중간 지연 확산을 가지는 채널 B보다 수신성능이 양호함을 알 수 있었으며, 채널 A와 B에 관계없이 제안된 레이크 수신기를 채용하였을 경우 자기 간섭의 제거 효과로 인해 수신성능이 기존의 레이크 수신기를 채용하였을 경우에 비해 향상됨은 알 수 있었다. 또한 간섭제거기와 제안된 레이크 수신기를 직렬로 연결한 수신기를 채용하였을 경우 다중접속간섭을 효과적으로 제거할 수 있었으며, 수신성능의 차이는 채널 환경이 양호할수록, $E_{b/}$N/ sub o/값이 커질수록 차이가 커짐을 알 수 있었다.다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.451-456
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• 1997

각 사업소의 교정용 팬톰에 대한 유효성 여부를 판정하고, 측정결과의 정확도와 조직적 오차의 발생여부를 확인할 목적으로 현재 국내 원전에서 사용중인 In Vivo 시스템에 대한 성능 시험을 수행하였다. 성능시험의 내용과 절차는 미국의 관련 지침인 ANSI N13.30에 기초를 두었다. 전신 측정에 대한 성능시험 결과, 시험핵종의 편중, 정밀도 및 최소검출방사능은 ANSI N13.30에서 정한 용인한도 이내로 나타났으며, 또 폐, 하복부 및 갑상선 측정에 대한 성능시험결과에 있어서도 성능평가 항목의 값은 모두 용인한도 이내였다. 각 사업소의 교정용 팬톰과 성능시험용 팬톰이 기하학적 구조에서 다소 차이가 있다 할지라도 측정결과의 편중이 용인한도 이하였다는 사실로부터 각 사업소에서 보유하고 있는 교정용 팬톰의 유효성을 간접적으로 입증할 수 있었다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.6
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• pp.427-436
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• 2009

In this study, new type of pile foundation was introduced for the better performance of lateral resistance than conventional piles by adopting enlarged upper section, because offshore structure design is subjected to the lateral loading. The numerical simulations were peformed in order to find out the lateral behaviour of the proposed pile. The economical efficiency of new pile system was also analyzed by considering the construction characteristics and material costs as well as the real field condition of harbor sites in Korea. From the study, it was revealed that the lateral resistance of piles with enlarged upper section is increased compared to conventional steel pile, and the construction costs would be reduced to about 62~80% of previous methods.

• Journal of Korean Society of Steel Construction
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• v.26 no.6
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• pp.537-547
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• 2014

A steel modular unit structural system has been used increasingly for mid and high-rise buildings, since the building can be easily constructed by assembling the pre-made modular unit structures. For this structural system, each modular unit structures have to be properly connected to the foundation to transfer the axial force and the bending moment that are generated from external load to the ground. In this study, a new type of the embedded steel column-to-foundation connection was proposed, and its flexural behavior was evaluated through a series of experimental study. Five full scale specimens for the proposed connections were constructed and tested. The effect of the main parameters that affect the flexural behavior of the proposed connection, such as embedment length and shape of end plate, were studied. From the results, it was found that the flexural stiffness of the proposed connection was higher than that of the semi-rigid connection for all test specimens, and 200 mm of embedment length was proper for the given test specimens in this study.