• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.917-926
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• 2010

It is known that bagging and boosting techniques improve the performance in classification problem. A number of researchers have proved the high performance of bagging and boosting through experiments for categorical response but not for continuous response. We study whether bagging and boosting improve data mining methods for continuous responses such as linear regression, decision tree, neural network through bagging and boosting. The analysis of eight real data sets prove the high performance of bagging and boosting empirically.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.4
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• pp.1-8
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• 2012

Domestic steel moment resisting frames were designed in accordance with the former KBC2005 and the current KBC2009, and then their seismic performance was evaluated in accordance with FEMA355F by utilizing nonlinear dynamic analysis. The results from the procedure in FEMA355F were different with those from the capacity spectrum method utilizing nonlinear static push-over analysis. In particular, the domestic steel moment resisting frames have a weak panel zone, so their behavior can be estimated more precisely by nonlinear dynamic analysis. The domestic steel moment resisting frames satisfied the performance goal if located at a site class $S_B$ or $S_C$, regardless of the story number and the response modification factor. However, if they are located at a site class $S_D$ or $S_E$, performance goal satisfaction cannot be guaranteed. No matter what standard is used for the design, KBC2005 or KBC2009, the domestic steel moment resisting frames may possess satisfactory seismic performance if the site condition is relatively good.

• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.519-527
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• 2021

In this study, an electromagnetic pulse shielding effect was obtained by applying the arc metal spraying method to the ordinary concrete. For this study, to evaluate the electrical properties in the thickness of the metal sprayed coating, 8 types of metals(Cu, CuAl, CuNi, CuZn, Al, Zn, ZnAl, AlMg) were sprayed as coatings with a thickness of 100, 200 and 500㎛. The electrical conductivity on the surface was measured with a 4-pin probe, and an electromagnetic wave shielding effect test was performed according to KS. Based on the test results, 200 ㎛ was proposed as an optimal metal coating thickness for electromagnetic pulse shielding, and it was thermally sprayed on a 300×300×100mm concrete specimen to analyze the electromagnetic wave shielding performance. However, in the area of adhesion strength, the maximum was 1.11MPa, which was found to be less than 74% of the target performance.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.378-387
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• 2007

In this paper, Authors develop and verify the algorithm for enhancing the performance of Unmanned vehicle's Autonomous navigation, and also propose the method of establishing much more precise Navigation locus. Unmanned vehicle has a destination, however orientation is not notified, which make it find the future orientation itself. Extended Kalman Filter make it access to the desirable direction, which coupled with INS and GPS is proposed in this paper. Sliding mode control could overcome the side slip and lateral minor movement of the vehicle. The test result would shows the effectiveness of Extended kalman filter and Slide mode control for the navigation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.40-42
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• 2015

Our D2D (Device-to-Device) advertisement dissemination algorithm based on the convergence of a D2D communication and a social commerce service is able to efficiently deliver advertisement messages of small business owners. We here assume high user-density areas as target-areas, and these target areas can form several target-groups based on geographical proximity. Also, the isolated target-areas which are not included in the target-groups may have the opportunities for forming a new target-group in consideration of the maximum distance with AP. In this paper, we evaluate performances with respect to the total number of successfully received users and the average number of relay users in accordance with variation in the maximum distance for isolated target-areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.66-66
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• 2022

아날로그 기법은 대표적인 공간상세화 기법 중 하나로써, 과거 기상 현상이 미래 재현된다는 가정 하에 목표 시점과 가장 유사한 기상패턴을 보이는 과거 시점을 활용하여 공간상세화를 수행하는 방법이다. 상세화 목표 시점과 가장 유사한 과거 시점을 찾기 위해서는 선결되어야 하는 매개변수가 존재한다. 특히 상세화 성능에 민감한 것으로 알려진 매개변수로는 목표 시점과 유사한 과거 시점 탐색에 활용되는 시공간 범위, 상세화 변수와 역학적 관계를 가지고 있는 종관기상변수, 상세화에 활용되는 과거 시점의 개수 등이 있다. 아날로그 기법의 매개변수를 탐색하고자 하는 시도는 국외에서 여러 차례 진행되어 왔으나, 각 매개변수는 지역의 기상특징에 따라 상이한 결과를 나타내었다. 국내에서는 국외에서 수행한 탐색 결과를 활용하여 공간상세화를 주로 수행하여 왔지만, 보다 높은 성능의 상세화를 수행하기 위해서는 국내 지역에 맞는 매개변수를 활용하는 것이 타당하다. 본 연구에서는 국내 지역에 적합한 아날로그 공간상세화 매개변수를 탐색하고 이를 제시하고자 한다. 탐색된 매개변수는 아날로그 공간상세화 기법뿐만 아니라 다양한 공간상세화 기법에 활용하능한 정보이기 때문에, 연구결과의 활용성이 높을 것으로 판단된다.

• Journal of Korean Society of Disaster and Security
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• v.15 no.4
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• pp.39-46
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• 2022

The rainfall characteristics such as heavy rains are changing differently from the past, and uncertainties are also greatly increasing due to climate change. In addition, urban development and population concentration are aggravating flood damage. Since the causes of urban inundation are generally complex, it is very important to establish an appropriate flood prevention plan. Thus, the government in Korea is establishing standards for disaster prevention performance for each local government. Since the concept of the disaster prevention performance target was first presented in 2010, the setting standards have changed several times, but the overall technology, methodology, and procedures have been maintained. Therefore, in this study, studies and technologies related to urban disaster prevention performance were reviewed using the scientometric analysis method to review them. This analysis is a method of identifying trends in the field and deriving new knowledge and information based on data such as papers and literature. In this study, papers related to the disaster prevention performance of the Web of Science for the last 30 years from 1990 to 2021 were collected. Citespace, scientometric software, was used to identify authors, research institutes, countries, and research trends, including citation analysis. As a result of the analysis, consideration factors such as the the concept of asset evaluation were identified when making decisions related to urban disaster prevention performance. In the future, it is expected that prevention performance standards and procedures can be upgraded if the keywords are specified and the review of each technology is conducted.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.11
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• pp.934-939
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• 2012

In this study, the performance validation of a PAO-AIR heat exchanger developed for the ECS(Environmental Control System) of a UAV(Unmanned Aerial Vehicle) has been carried out. The performance goals of a PAO-AIR heat exchanger were established by the system schematic analysis. And a heat exchanger to be met the ECS performance was developed by a detailed design and a precision manufacture. Using the developed heat exchanger, the experiment about pressure loss and effectiveness, overall heat transfer coefficient to prove the developed PAO-AIR heat exchanger performance in various conditions as well as a design point of heat exchanger was performed and the experimental results were analyzed. As the experimental results, the performance and characteristic of a PAO-AIR heat exchanger developed for the ECS of a UAV were analyzed and the development suitability was proved.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.23-31
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• 2018

Recently, there was an collision accident of vehicle-concrete median barrier and unfortunately, passengers were killed by exceeded capacity of concrete median. Therefore, improving the capacity of concrete median barrier is need to reduce damage. Accordingly, in this study, appropriate collision model verified by using the FE analysis program LS-Dyna and recommend a concrete median barrier section. The improvement parameters such as wire mesh diameter, steel plate, rubber pad were selected for improved capacity of the median barrier. Finally, section of concrete median barrier improved wire mesh diameter decreased volume loss, section of concrete median barrier improved rubber pad accepted impact loading and increased elastic area.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.373-375
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• 2004

소프트웨어가 수행되는 환경은 점점 복잡해지고, 예측이 어려워지고 있지만, 소프트웨어의 자율성과 견고성을 달성하는 것은 여전히 어려운 문제 중에 하나이다. 적응형 소프트웨어는 소프트웨어의 복잡성을 해결하고 자율성과 견고성을 달성하는데 기여할 새로운 소프트웨어 개발 패러다임으로 떠오르고 있다. 적응형 소프트웨어는 환경과 자신의 상태를 인지하고 현재의 성능을 향상시킬 방법을 스스로 판단하여 소프트에어의 구조 및 행위를 변경할 수 있는 소프트웨어이다. 본 논문에서는 적응형 소프트웨어의 개발 초기단계에서 요구사항 분석 단계에서 추출된 목표와 시나리오를 이용하여 어떻게 적응형 소프트웨어의 각 기능을 정의하는 방안을 제시한다.