• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.1-10
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• 2017

Advanced ICT Technologies support the chance for success in business however there are challenges that should be overcome in messenger development and the overcoming challenges will be a base line for succession in business. In this paper, we identify the characteristics of mobile messengers and evaluate users' preferences using AHP. As a result, we evaluated the critical success factors which are important in mobile messenger development. The results of AHP were generated 0.098 consistency ratio(CR). When the result is less than 0.1 in CR, the result could be accepted as trusted questions. The priority of factors was security(1.409), entertainment(0.19), communication (0.187) then this shows the users concerned in security and entertainment. These are not only development's success factors but also a good milestone to check ICT trends for setting up business chances.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.1-12
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• 2009

The correct detection of skin color is an important preliminary process in fields of face detection and human motion analysis. It is generally performed by three steps: transforming the pixel color to a non-RGB color space, dropping the illuminance component of skin color, and classifying the pixels by the skin color distribution model. Skin detection depends on by various factors such as color space, presence of the illumination, skin modeling method. In this paper we propose a 3d skin color model that can segment pixels with several ethnic skin color from images with various illumination condition and complicated backgrounds. This proposed skin color model are formed with each components(Y, Cb, Cr) which transform pixel color to YCbCr color space. In order to segment the skin color of several ethnic groups together, we first create the skin color model of each ethnic group, and then merge the skin color model using its skin color probability. Further, proposed model makes several steps of skin color areas that can help to classify proper skin color areas using small training data.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.97-99
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• 2003

In order to confirm the possibility of application of laser welding process to 2.25Cr-1Mo steel, the characteristic of residual stress distribution in welds by SMAW and $CO_{2}$ Laser welding process have been investigated and compared using the numerical analysis. As the Result of the numerical analysis, the possibility of application of laser welding process has been found out in respect to the welding residual stress distribution and mechanical properties in welds.

• Journal of The Korean Radiological Technologist Association
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• v.27 no.2
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• pp.22-34
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• 2001

DR은 방사선과 뿐만 아니라 병원전체의 생산성 및 업무의 효율성에서 중요한 요소로 자리잡아가고 있다. DR환경은 CR보다 다양한 Parameter를 가지고 있어 양질의 의료서비스 제공이 가능하다. 현재 각 병원의 방사선과는 Film-Screen system에서 Full-PACS를 통한 DR 환경으로 변화하고 있다. Full- PACS를 사용하고 있는 본원에서는 DR환경에서의 일반촬영 System중 CR과 DDR의 최적노출조건과 그에 따른 Image qu

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.191-200
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• 2005

The main purpose of the present study was to find the effect of short term creating loading on repeated bouts of kicking, plasma creating phosphokinase and anaerobic power in male taekwondo player from high school. Sixteen male were randomly assigned to two groups. They were tested before and after 6 days of placebo$(4{\times}5g\;glucose\;d^{-1},\;N=11)$ or Creatine monohydrate loading$(consume\;0.3g\;kg^{-1},\;N=11)$. Repeated bouts of kicking was tested through maximal front kicking continuously for 1 minute and took a rest for 30 seconds, after 30 seconds rest they should have to start kicking again. They repeated it 2 times more(total 3 sets) and the kicking times were measured each sets. Also, body composition, CPK, mean power and peak power were measured before and after experiment. The following results were obtained from this study; 1. The kicking test was significantly increased at 1, 2, 3 sets only in creatine loading group(p<.05, p<.01). 2. Only creatine loading group was significantly increased of plasma creatine phosphokinase(p<.01). 3. Only creatine loading group were significantly increased both of mean power and peak power(p<.05; p<.01). These results suggest that short creatine loading was effective diet protocol in taekwondo player from male high school.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.1
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• pp.1-6
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• 2017

This paper presents development of the nine-node co-rotational(CR) planar element applicable for elastoplastic and contact analysis. The CR formulation is one of the efficient geometrically nonlinear formulations. It is based on the assumptions of small strain and large displacement. Further, it is extended to both elastoplastic analysis and contact analysis in this paper. For accurate plastic analysis, nine-node quadrilateral element, which can provide accurate stress prediction, is chosen. Bi-linear hardening rule based on Newton- Raphson return-mapping is employed. Also, Lagrange multiplier is used in order for constraints regarding the contact analysis. The present development is validated via the time transient problems. The present results are compared with those obtained by the other existing software.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.565-571
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• 2020

In this paper, precision and efficient nonlinear structural analysis for the aircraft wing-box model is developed. Herein, nonlinear shell element based on the co-rotational (CR) formulation is implemented. Then, parallel computing algorithm, the element-based partitioning technique is developed to accelerate the computational efficiency of the nonlinear structural analysis. Finally, computational performance, i.e., accuracy and efficiency, of the proposed analysis is evaluated by comparing with that of the existing commercial software.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.111-116
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• 2001

Small punch-creep(SP-Creep) test technique has been applied for evaluating the creep characteristics for high temperature materials. However, in order to evaluate the damage and predict the remaining life, it is necessary to establish a quantitative correlation between SP-Creep and uniaxial-creep test results. This paper presents analytical and experimental results of useful correlation between SP-Creep and uniaxial-creep properties for 9Cr1MoVNb steel at $600{\sim}650^{\circ}C$ in terms of stress(load) and activation energy during creep deformation. Especially, the activation energy obtained from SP-Creep test is linearly related to that from uniaxial-creep test at $650^{\circ}C$ as follows: $Q_{sp-p}{\fallingdotseq}1.37\;Q_{TEN},\;Q_{sp-{\sigma}}{\fallingdotseq}1.53\;Q_{TEN}$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.67-68
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• 2016

해상교통환경평가는 선박 간 항행상황의 위험도를 정량화하여 나타냄으로써 선박의 안전운항을 효과적으로 지원하는 역할을 한다. 대표적인 해상교통환경평가모델로는 ES(Environmental Stress model)와 CR(Collision Risk)모델이 있다. 이러한 모델을 살펴보면, 각각의 평가지수를 이용하여 항행상황의 위험도를 정량화하며, 선박 간 조우관계를 기반으로 평가요소를 구성함을 알 수 있다. 이번 연구에서는 선박 간 조우관계를 포함한 항행상황의 위험도에 영향을 줄 것으로 기대되는 다양한 요소를 고려한 평가지수의 타당성을 살펴보고자 한다. 이를 위하여, AIS data를 이용하여 해상교통환경을 재현하고 분석하였으며, 동일한 항행상황을 ES, CR과 제안한 모델을 이용하여 위험도 평가를 실시하였다. 그 결과를 비교하여 제시함으로써 본 모델이 해상교통환경모델로서 항만 내 통항 안전성 평가에 적용 가능성을 평가하였다.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.274-278
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• 2003

In recent, an application of high energy density beam we/ding is increasing to obtain the high quality in weldments. Laser welding, especially, has been recognized as an useful method and its beam power has also increased according to the development of relevant technology. However, welding method in the fields of power plant is conservative because their structures have required to endure high temperature and pressure. So, authors conduct the numerical simulation in order to consider the possibility of laser welding on the material of the pressure vessels ($2\frac{1}{4}Cr-1Mo$ steel). As a result of this study, we can confirm the advantages of laser welding and obtain useful information for the experiments of weldability.