• Computational Structural Engineering
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• v.18 no.1 s.67
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• pp.51-55
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• 2005

• Computational Structural Engineering
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• v.22 no.3
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• pp.88-93
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• 2009

• Computational Structural Engineering
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• v.22 no.3
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• pp.94-98
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• 2009

• Computational Structural Engineering
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• v.22 no.4
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• pp.84-88
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• 2009

• Journal of information and communication convergence engineering
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• v.20 no.4
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• pp.259-264
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• 2022

In wireless sensor networks, sensor nodes are often deployed in large numbers in places that are difficult for humans to access. However, the energy of the sensor node is limited. Therefore, one of the most important considerations when designing routing protocols in wireless sensor networks is minimizing the energy consumption of each sensor node. When the energy of a wireless sensor node is exhausted, the node can no longer be used. Various protocols are being designed to minimize energy consumption and maintain long-term network life. Therefore, we proposed KOCED, an optimal cluster K-means algorithm that considers the distances between cluster centers, nodes, and residual energies. I would like to perform a performance evaluation on the KOCED protocol. This is a study for energy efficiency and validation. The purpose of this study is to present performance evaluation factors by comparing the K-means algorithm and the K-medoids algorithm, one of the recently introduced machine learning techniques, with the KOCED protocol.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.379-384
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• 2022

In a wireless sensor network, a large number of sensor nodes are deployed in an environment where direct access is difficult. It is difficult to supply power, such as replacing the battery or recharging it. It is very important to use the energy with the sensor node. Therefore, an important consideration to increase the lifetime of the network is to minimize the energy consumption of each sensor node. If the energy of the wireless sensor node is exhausted and discharged, it cannot function as a sensor node. Therefore, it is a method proposed in various protocols to minimize the energy consumption of nodes and maintain the network for a long time. We consider the center point and residual energy of the cluster, and the plot point and K-means (WSN suggests optimal clustering). We want to evaluate the performance of the KOCED protocol. We compare protocols to which the K-means algorithm, one of the latest machine learning methods, is applied, and present performance evaluation factors.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.532-536
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• 2006

분산공유형 건설연구인프라 구축사업(Korea Construction Engineering Development Collaboratory)은 국내에 분산되어 있는 건설기술연구 및 교육 인프라를 공유하기 위해 제안되었다. KOCED의 인터넷 기반 그리드 시스템과 어플리케이션을 이용함으로써 원격의 사용자는 여러 개의 분산된 시설을 이용하여 실험을 할 수 있고, 이를 각 분야의 전문가들과 공유함으로써 협력작업을 할 수 있다. 이러한 KOCED 그리드 인프라를 사용함으로써 소프트웨어 코드와 물리적 기기를 연동하여 실험하는 하이브리드 시뮬레이션이 가능하다. 본 논문에서는 KOCED 그리드 시스템에서 어떻게 mini-MOST 하이브리드 시뮬레이션이 구현되었는지 기술하고, 하이브리드 시뮬레이션의 실행 속도와 효율성을 개선시키기 위한 방법을 논하고자 한다.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.190-202
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• 2018

Maintaining the integrity of the major equipment in nuclear power plants is critical to the safety of the structures. In particular, the soundness of the piping is a critical matter that is directly linked to the safety of nuclear power plants. Currently, the limit state of the piping design standard is plastic collapse, and the actual pipe failure is leakage due to a penetration crack. Actual pipe failure, however, cannot be applied to the analysis of seismic fragility because it is difficult to quantify. This paper proposes methods of measuring the failure strain and deformation angle, which are necessary for evaluating the quantitative failure criteria of the steel pipe elbow using an image measurement system. Furthermore, the failure strain and deformation angle, which cannot be measured using the conventional sensors, were efficiently measured using the proposed methods.

• Wind and Structures
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• v.14 no.1
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• pp.55-70
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• 2011

This study investigates the design criteria required for wind barriers to protect vehicles running on an expressway under a high side wind. At the first stage of this study, the lateral deviations of vehicles in crosswinds were computed from the commercial software, CarSim and TruckSim, and the critical wind speeds for a car accident were then evaluated from a predefined car accident index. The critical wind speeds for driving stability were found to be 35 m/s for a small passenger car, yet 30 m/s for a truck and a bus. From the wind tunnel tests, the minimum height of a wind barrier required to reduce the wind speed by 50% was found to be 12.5% of the road width. In the case of parallel bridges, the placement of two edge wind barriers plus one wind barrier at center was recommended for a separation distance larger than 20 m (four lanes) and 10 m (six lanes) respectively, otherwise two wind barriers were recommended.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.149-157
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• 2014

In this paper, we investigated the sensitivity of aerostatic force coefficients of multi-layer radom in the various wind speeds. The test was conducted in KOCED Wind Tunnel Center in Chonbuk National University, and wind speeds were in the range from 5 m/s to 26 m/s in order to determine the Reynolds number independence. The test results of present multi-layer radom were not affected by the Reynolds number, The maximum positive pressure coefficient was found to be 1.08 at the center of the front of the plane in angle of attack of 0 degree, the maximum negative pressure coefficient was -2.03 at the upper right corner in angle of attack of 120 degree, while maximum drag coefficient was 1.11 in angle of attack of 180 degree.