• 한국정보통신학회논문지
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• 제21권11호
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• pp.2191-2198
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• 2017

군 무기체계의 성능을 점검하기 위해 사용되는 정밀측정장비는 수명주기 동안 측정신뢰도 유지를 위해 주기적으로 교정된다. 기존의 교정주기 관련 연구들은 장비의 샘플 크기와 특성을 고려하여 측정신뢰도 모델을 결정할 것을 제안하고 있으나, 다양한 정밀측정장비의 정비 데이터에 동일한 특성 분포를 가정하고 단일 모델을 적용하는 것은 적합하지 않을 수 있다. 본 논문에서는 정밀측정장비의 수명주기 동안 욕조 곡선의 특성을 가정하여 측정신뢰도 모델들로부터 추정된 교정주기 가운데 F-검정과 성능지수 평가를 통해 정비 데이터에 가장 적합한 교정주기가 선택되도록 제안하였다. 제안한 방법을 다양한 장비에 적용한 결과 교정주기 동안 장비의 신뢰도가 유지됨을 확인하였다.

• 농촌지도와개발
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• 제20권3호
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• pp.701-727
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• 2013

농촌의 인구활력화, 지역경제 활성화, 농촌의 문화다양성, 농촌 가족사회의 유지, 그리고 농촌자원의 향상과 같은 다문화가족이 농촌사회에 미치는 영향 및 기여가치에 대한 WTP(Willingness to Pay)를 추정하기 위해, 농촌지역 41개 시 군에서 weibull model에 기초한 이중이선선택법으로 조사가 이루어졌다. 이어 추정모형을 개발하고 로지스틱(logistic)을 이용해 WTP를 추정하였다. 추정결과, 다문화가족의 기여가치 유지를 위해 농촌지역민이 평가한 WTP는 458억원이었고, 이것은 개개 농촌가구가 연간 13,840원을 지불할 수 있음을 의미한다. 비교준거로서 다문화가족 남편이 평가한 WTP는 502억원 이었고 이것은 개개 농촌가구가 연간 15,170원을 지불할 수 있음을 의미한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.482-486
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• 1995

Generally, a great deal of attention is given to the maintenance of consistent surface roughness. Therefore one of the major goals of research in this area has been the development of models which can predict the surface roughness obtainable on a machined metal part over the simultaneous variation of cutting condition. A comparison is also made between the theoretical and actual values of surface roughness to calculate the overall variance in the developed models, Mathematical models developed from the experimental data in the course of this work can be employed to control the cutting conditions in order to achieve the desired surface roughness and deep quality.

• 한국산업정보학회논문지
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• 제19권2호
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• pp.51-58
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• 2014

As WSNs(Wireless Sensor Networks) are being deployed widely in diverse application areas, their management and maintenance become more important. Recent sensor node software takes modular software architectures in pursuit of flexible software management and energy efficient reprogramming. To realize an flexible and efficient modular architecture particularly on resource constrained mote-class sensor nodes that are implemented with MCUs(Micro-Controller Units) of a single address space. an appropriate module linking model is essential to resolve and bind the inter-module global symbols. This paper identifies a design space of module linking model and respectively their implementation frameworks. We then establish a taxonomy for module linking models by exploring the design space of module linking models. Finally, we suggest an implementation framework respectively for each module linking model in the taxonomy. We expect that this work lays the foundations for systematic innovation toward more flexible and efficient modular software architectures for WSNs.

• 산업공학
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• 제16권1호
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• pp.63-69
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• 2003

Virtual Manufacturing is a technology facilitating effective development and agile production of products via computer models representing physical and logical schema and the behavior of the real manufacturing systems including manufacturing resources, environments and products. For the successful application of this technology, a virtual factory as a well-designed and integrated environment is essential. To construct a virtual factory in effective and concurrent manners, a supporting information infrastructure for managing diverse models of virtual factory is very important. In this paper, we constructed the web-based information management system for many engineering activities related with a virtual factory. Using this system, users can handle all information and diverse digital files including attributes, parameters, 3-D CAD files, simulation models, and etc. of a cell, line and whole factory. We expect that this information management system for a virtual factory helps us achieve great time savings and advances in accuracy for construction and maintenance activities of virtual factories.

• 국제강구조저널
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• 제18권4호
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• pp.1219-1241
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• 2018

This study aims towards the improvement of a reinforced concrete rigid-frame bridge in an effort to reduce the construction and maintenance costs, and achieve an improved seismic performance. Correspondingly, a new structural rigid connection is proposed for H-shaped steel girders and reinforcing bars at the corner of the rigid-frame structure. Both experiments and numerical analyses were performed. Prototype models were constructed and subjected to static loading tests to reveal their load-carrying capacity and failure mode. Numerical models were then developed using finite elements to evaluate the experimental results. Analyses elicited good agreement between simulation and experimental data and validated the numerical models. Moreover, the validity of the proposed rigid connection was confirmed, and the failure behavior was clarified. Finally, a full-size model of the reinforced concrete rigid-frame bridge with H-shaped steel girders was constructed and subjected to destructive loading tests to evaluate structural integrity of the proposed rigid connection.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.239-240
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• 2023

Construction site management involves overseeing tasks from the construction phase to the maintenance stage, and digitalization of construction sites is necessary for digital construction site management. In this study, we aim to conduct research on object recognition at construction sites using drones. Images of construction sites captured by drones are reconstructed into BIM (Building Information Modeling) models, and objects are recognized after partially rendering the models using artificial intelligence. For the photorealistic rendering of the BIM models, both traditional filtering techniques and the generative adversarial network (GAN) model were used, while the YOLO (You Only Look Once) model was employed for object recognition. This study is expected to provide insights into the research direction of digital construction site management and help assess the potential and future value of introducing artificial intelligence in the construction industry.

• Structural Monitoring and Maintenance
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• 제10권4호
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• pp.339-360
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• 2023

In this paper, to assess the performance of a multi-span simply supported RC bridge, the dynamic characteristics of the bridge were measured and determined by structural health monitoring and resilient assessment via operational modal analysis as well as FE modeling. Supporting finite element (FE) models were created and analyzed according to the design drawings. This study used 2D plane monitoring of locations of hole in the infill wall and used 3D health monitoring and resilient assessment. From the results of 3Dsymmetric frame, if the frame is unsymmetrical, the used model can lead to the reduction in the internal forces. The recommendations from this study is from some discrepancies observed between 2D and 3D models, if possible 3D model should be used in analyzing the real frames.

• Computers and Concrete
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• 제17권3호
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• pp.353-386
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• 2016

Realistic assessment of the performance of reinforced concrete structural members like columns is needed for designing new structures or maintenance of the existing structural members. This assessment requires analytical capability of employing proper material models and cyclic rules and considering various load and displacement patterns. A computer application was developed to analyze the non-linear, cyclic flexural performance of reinforced concrete structural members under various types of loading paths including non-sequential variations in axial load and bi-axial cyclic load or displacement. Different monotonic material models as well as hysteresis rules, were implemented in a fiber-based moment-curvature and in turn force-deflection analysis, using proper assumptions on curvature distribution along the member, as in plastic-hinge models. Performance of the program was verified against analytical results by others, and accuracy of the analytical process and the implemented models were evaluated in comparison to the experimental results. The computer application can be used to predict the response of a member with an arbitrary cross section and various type of lateral and longitudinal reinforcement under different combinations of loading patterns in axial and bi-axial directions. On the other hand, the application can be used to examine analytical models and methods using proper experimental data.

• 한국국방경영분석학회지
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• 제35권3호
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• pp.31-45
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• 2009

시스템의 성능과 안전성을 보장하기 위해서는 개발 초기부터 신뢰도에 대한 연구가 이루어져야 한다. 시스템의 목표 신뢰도를 수립하고, 이를 달성하기 위하여 하부시스템 및 부분품에 신뢰도를 할당해야 한다. 시스템의 획득 및 개발에 있어서 성능이 우수하고 비용이 저렴하더라도 고장이 빈번하게 발생한다면 원활한 임무 수행에 많은 영향을 미치고, 막대한 운영유지비용이 소요될 것이다. 본 연구에서는 신뢰도 할당 모형과 운영 유지비용과의 관계를 알아보기 위하여 기존의 알려진 신뢰도 할당 모형들을 검토 및 평가하였다. 신뢰도 할당모형의 평가는 차기 개발 함정용 디젤 엔진을 대상으로 하였으며, 다양한 신뢰도 할당 모형에 목표 신뢰도를 고려하여 신뢰도를 할당하고, 현재 운영하는 함정용 디젤 엔진의 자료를 바탕으로 시뮬레이션을 수행하여 운영유지비용을 최소화하는 신뢰도 할당 모형을 선정하였다.