• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.10a
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• pp.337.1-337
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• 1994

동기식 광전송망에서는 망의 생존도를 고려하여 다양한 형태의 망구조가 제안되고 있다. 본 연구에서는 수요가 한 방향으로만 처리되는 ADM을 이용한 USHR선정문제를 다룬다. USHR설계문제에서는 노드간의 수요를 처리하기 위하여 장비의 위치선정, ADM간의 연결을 위한 Ring 경로선정문제, ADM이 설치되지 않은 노드와 ADM간의 연결방법, Ring용량결정등 많은 의사 결정이 이루어져야 한다. 특히 주어진 노드 간에 하나 이상의 SHR을 설치해야 하는 경우에는 매우 복잡한 문제가 되기 때문에 최적화 모형을 수립하여 문제를 해결하는 것이 불가능하다. 따라서 본 연구에서는 주어진 노드집합에 대하여 모든 노드에 ADM이 설치되는 가정하에서 Ring의 용량제약을 고려한 USHR선정모형 및 효과척인 해법을 제시한다.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.251-256
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• 2011

Virtual colonoscopy is favored over conventional colonoscopy because its non-invasive procedure can avoid complications that may happen in a conventional approach and because it can cleanse colon electronically instead of uncomfortable conventional colon cleansing. Electronic Colon Cleansing(ECC) has to deal with not only removing tagged fecal material but also recovering Partial Volume Effect(PVE) due to tagging material. This paper proposes an ECC method restoring inherent natural PVE while previous approaches focused only on reducing PVE due to tagged fecal material. The proposed method reduces PVE using 3-dimensional adaptive density correction and then replaces tagged fecal material into air. Next, it generates natural PVE for the replaced air adjacent to soft tissue and finally makes smooth transition of gray values for soft tissue adjacent to the replaced air. The proposed method applied to eleven patient data, and showed promising results.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.159-163
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• 2008

This paper proposes various measures of reliability, maintainability and availability in information technology service management(ISTM). Global ITSM standards such as ITIL(IT Infrastructure Library) and ISO/IEC 20000 are introduced. Especially availability management of De-facto and De-juire standards is concerned with users and customers of IT service. The study presents seven reliability measures, six maintainability measures and two availability measures. These results can be effectively used with a appropriate IT availability management tools such as CFIA(Component Failure Impact Analysis) and SOA(Service Outage Analysis), etc.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.637-643
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• 2005

A new novel Whipping Factor is proposed as a measure of the ship damage potential due to an underwater explosion bubble pulse. The factor was derived from the relationships among the charge weight, its depth and the fluid acceleration due to pulsating gas bubble. From the whipping response analyses for three uniform Timoshenko beams with similar characteristics of real naval surface ships, we have confirmed the maximum bending moment responses of beams due to whipping are almost same if the applied whipping factor is constant regardless of the charge weights and depths, which could validate the proposed whipping factor.

• Journal of the Korean Home Economics Association
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• v.39 no.1
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• pp.221-232
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• 2001

The purpose of this study was to develop a scale for evaluation of preschool children's peer competence and to examine its validity and reliability. The 15 items of the preliminary scale were completed by teachers, and peer rating scale for assessment of peer acceptance was administered to 365 children 5 to 6 years of age. The methods for data analysis included item analysis, factor analysis for construct validity, Pearson correlations between teacher's ratings of peer competence and children's ratings of peer acceptance for concurrent validity, and Cronbach's u for reliability. The 15 items of the scathe were found be satisfactory in terms of item response distribution and item discrimination. Factor analysis revealed that a 3-factor solution was the best fit: sociability, prosocial behavior, leadership in peer relations. Correlations between teacher's ratings and children's ratings were as significant. Cronbach'so ranged from .88 to .93 for three subscales and .93 for the total scale. It was concluded that the psychometric properties of the peer competence scale in general were acceptable for use.

• Journal of Drive and Control
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• v.12 no.1
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• pp.21-27
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• 2015

Pneumatic cylinders are classified into rod-type pneumatic cylinders and rodless pneumatic cylinders depending on the presence of the rod. Rodless cylinders have a constant area and have no deflection. Rodless cylinders are widely used in automatic systems requiring high-speed performance and high-precision transportation. However, the research of the pneumatic cylinder has been focused on the structure and life characteristics. In this research, aging characteristics and shape parameter analysis which are related to the lifetime were investigated. By conducting the lifetime tests with two different materials for the transfer plate, the failure mode and lifetime characteristics were analyzed. By the Anderson-Darling (A-D) verification based on the complete data set, the analysis results of lifetime distribution, shape parameter, and scale parameter were provided.

• Journal of the Korean housing association
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• v.22 no.2
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• pp.111-120
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• 2011

This study examined significant factors explaining college students' place attachment to their childhood homes, developed the scale of that, and proposed statistically significant models to explain their place attachment to those home environments. We conducted a questionnaire survey with 32 items. Responses from 358 Michigan State University students were analyzed statistically. From the explanatory and confirmatory factor analysis, 31 items under 4 valid factors named Place dependence, Affection, Rootedness, and Place identity were obtained. This study additionally adapted six types of place attachment to childhood homes from Hess (1997), and examined these types. Idealization (Type1), affection (Type3), and transcendence (Type5) were chosen most often. Finally, this study explored the relationships between housing satisfaction and (1) the four place attachment factors and (2) the six types of place attachment. Results showed the four place attachment factors were more strongly related with housing satisfaction.

• Journal of Families and Better Life
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• v.21 no.2
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• pp.31-38
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• 2003

This study was conducted to develop a Parenting Stress Scale that measures the day-to-day difficulties entailed in parenting for school-aged children. First, sixty seven items were collected as a baseline. Some of these items were pooled from existing parenting stress scales(Abidin, 1990; Kim & Kang, 1997), and the rest were generated based on interviews with parents of school-aged children. Secondly, Chi-Square tests were conducted and framer's V coefficients were calculated to determine the goodness-of-fit of the items. Twenty four items were selected from this step. The results of a factor analysis on these 24 items revealed two dimensions of this new Parenting Stress Scale, namely, 'school-related parenting stress' and 'general everyday life stress'. A test of construct validity also showed that this scale has adequate internal consistency.

• Review of KIISC
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• v.22 no.1
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• pp.7-13
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• 2012

최근까지 정보 기술 분야에서는 유비쿼터스(Ubiquitous)라는 용어가 크게 유행한 척이 있다. 현재는 다소 식상하게 들리는 용어일지도 모르지만 사물의 지능화와 통신화라는 유비쿼터스 개념은 이미 우리의 생활에 깊이 파고 들어왔다. 최근 유행하는 IT 기술인 스마트폰이나 지능형 전력망, 와이파이, 소셜 네트워크, 센싱 데이터 처리 기술과 개념은 이러한 유비쿼터스 기술의 대표적인 사례로 볼 수 있다. 국내에서 는 이러한 유비쿼터스라는 개념을 유비쿼터스 센서 네트워크(Ubiquitous Sensor Network: USN)라는 용어로서 2004년부터 정보통신부 혹은 지식경제부의 적극적인 지원에 힘입어 많은 기술적/산업적 성과를 이루기도 했다. 하지만 이러한 USN은 센서네트워크 개념으로 제한적으로 오용되는 경우가 많았다 이에 본고에서는 이러한 유비쿼터스 환경을 실현하는 사물의 지능화/통신화에 대한 기술 동향과 보안 기술을 논하기 위해서 USN과 거의 비슷한 개념이지만 국내외적으로 더욱 보편적으로 사용되고 있는 IoT(Intemet of Things) 용어를 사용할 것이며, 이러한 IoT에 대한 기술 동향과 보안 기술을 논하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.607-608
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• 2013

무선 애드훅 네트워크에서는 무선링크의 성능을 표현하는 다양한 품질 척도가 있다. 그것은 노드가 움직임이 없는 상태에서 주변 무선 상태를 반영한다. 하지만 해상 환경에서는 선박의 이동성 뿐만 아니라 바람과 파고에 의해 선박이 움직이는 특성이 있다. 따라서 선박에 위치한 안테나의 흔들림을 유발하여 신호의 수신을 불안정하게 만든다. 본 논문은 선체운동에 따른 무선 링크 성능을 분석한다. 이를 위해 자이로 센서를 이용하여 서로 다른 해상 환경에서 선체운동을 측정 및 분석하고, 하드웨어 및 소프트웨어에 의한 무선 링크 안정화 방안을 제시한다.