• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1286-1288
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• 1996

An add/drop control chip for SDH transmission system has been designed in AT&T 0.5um CMOS ORCA FPGA. This device plays an important role in achieving self-healing ring operation which protects against failure. After this device receives each 24-ch AU-3 signals from the west, east, and add parts, it outputs each 24-ch switched signals through the control data of system control port. This device consists of eight sub-part such west/east transmitting part, west/east receiving part, add/drop control part, AIS control part, and CPU interface part. The designed device is capable to ring networks as well as linear networks.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.237-238
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• 2019

As part of the development of building technology to improve the living performance closely related with lifestyle to Realize the Housing Welfare, the standard manual for the prevention and maintenance of water leaks in the underground structures of apartment buildings consists of Part 1 and Part 2. This study further covered the maintenance plan and inspection carried out in Part 1.

• 설비공학논문집
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• 제28권3호
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• pp.115-122
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• 2016

In this study, 21 energy reduction factors were selected as architecture, system & operation, and lighting and equipment parts to analyze reduction method of the load occurring in office buildings. Energy consumption simulation was performed. In the architecture part, saving rate (1.53%) of "occupant density" factor was the most efficient. In the system and operation part, saving rate (1.28%) of "interior VAV and exterior FPU type" factor was the most efficient. In case of lighting and equipment part, saving rate (12.42%) of "schedule" factor was the most efficient. In the three parts, saving rate of the lighting and equipment part was 27.32%. This was caused by the "schedule" factor. Saving rates of the architecture part and the system and operation part were 3.39% and 1.20%, respectively.

• Structural Engineering and Mechanics
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• 제69권1호
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• pp.105-120
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• 2019

In this paper, a new efficient method for structural modal reanalysis is proposed, which can handle large finite element (FE) models requiring frequent design modifications. The global FE model is divided into a residual part not to be modified and a target part to be modified. Then, an automated matrix permutation and substructuring algorithm is applied to these parts independently. The reduced model for the residual part is calculated and saved in the initial analysis, and the target part is reduced repeatedly, whenever design modifications occur. Then, the reduced model for the target part is assembled with that of the residual part already saved; thus, the final reduced model corresponding to the new design is obtained easily and rapidly. Here, the formulation of the proposed method is derived in detail, and its computational efficiency and reanalysis ability are demonstrated through several engineering problems, including a topological modification.

• 국제강구조저널
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• 제18권5호
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• pp.1761-1771
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• 2018

In this paper, a hysteretic model of rectangular hollow section (RHS) columns that includes the deteriorating range caused by local buckling is proposed. The proposed model consists of the skeleton curve, the Bauschinger part that appears before reaching the maximum strength, the strength increasing part of the deteriorating range, and the unloading part. Of these, the skeleton curve, including the deterioration range caused by local buckling, which is considered to be equivalent to the load-deformation relationship under monotonic loading, is obtained through an analytical method. Bi-linear hysteretic models based on experimental results are applied to the Bauschinger part and the strength increasing part. The elastic stiffness is applied to the unloading part. The proposed model is verified by comparing with experimental results of RHS columns under monotonic and cyclic loading.

• 한국정밀공학회지
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• 제14권8호
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• pp.122-129
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• 1997

In this paper, we propose a Hopfield model for solving the part-matching in case that is the number of parts and positions are changed. The goal of this paper is to minimize part-connection in pairs and total path of part-connections. Therefore, this kind of problem is referred to as a combinatiorial optimization problem. First of all, we review the theoretical basis for Hopfield model and present two optimal algorithms of part-matching. The first algorithm is Traveling Salesman Problem(TSP) which improved the original and the second algorithm is Wdighted Matching Problem (WMP). Finally, we show demonstration through com- puter simulation and analyze the stability and feasibility of the generated solutions for the proposed con- nection methods. Therefore, we prove that the second algorithm is better than the first algorithm.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.98-99
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• 2020

The objective of the study is to investigate the compressive strength of damaged part by early frost damage and sound part of the concrete placed when exposed to a low temperature of -20℃ for 24 hours in normal concrete. Test results indicated that the compressive strength of damaged part was 14.5 MPa lower than that of sounf part due to early frost damage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.791-792
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• 2007

• 열처리공학회지
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• 제26권2호
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• pp.59-65
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• 2013

The microstructures and hardness distributions of a large-sized high strength H-sectional steel with both V and Nb were systematically examined. The outer surface of the flange part was composed of martensite and bainite due to faster cooling, and had a high hardness value of approximately 310 Hv. However, the amounts of ferrite and pearlite increased and the hardness decreased with increasing the distance from the outer surface at the flange part, except the inner surface. High hardness value of about 290 Hv was measured at the upper surface of the web part having martensite and bainite. The hardness drastically decreased with increasing the web thickness, and then greatly rose again at the lower surface due to bainite formation caused by fast air cooling. The hardness of the flange part was higher than that of the web part due to the larger amount of low-temperature transformed phases, except for the lower surface of the web part. Nb-rich precipitates of 30 to 50 nm and V-rich precipitates less than 20 nm were observed at both flange and web parts. However, the particle size was smaller at the flange part than the web part, resulting in the higher strength of the flange part.

• 산업경영시스템학회지
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• 제39권3호
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• pp.83-89
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• 2016

The group formation problem of the machine and part is a critical issue in the planning stage of cellular manufacturing systems. The machine-part grouping with alternative process plans means to form machine-part groupings in which a part may be processed not only by a specific process but by many alternative processes. For this problem, this study presents an algorithm based on self organizing neural networks, so called SOM (Self Organizing feature Map). The SOM, a special type of neural networks is an intelligent tool for grouping machines and parts in group formation problem of the machine and part. SOM can learn from complex, multi-dimensional data and transform them into visually decipherable clusters. In the proposed algorithm, output layer in SOM network had been set as one-dimensional structure and the number of output node has been set sufficiently large in order to spread out the input vectors in the order of similarity. In the first stage of the proposed algorithm, SOM has been applied twice to form an initial machine-process group. In the second stage, grouping efficacy is considered to transform the initial machine-process group into a final machine-process group and a final machine-part group. The proposed algorithm was tested on well-known machine-part grouping problems with alternative process plans. The results of this computational study demonstrate the superiority of the proposed algorithm. The proposed algorithm can be easily applied to the group formation problem compared to other meta-heuristic based algorithms. In addition, it can be used to solve large-scale group formation problems.