• Proceedings of the Safety Management and Science Conference
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• 2002.05a
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• pp.199-205
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• 2002

최근 산업안전/보건분야에서 누적외상성질환(Cumulative Trauma Disorders： CTDs)과 직업성요통(Low Back Injury)과 같은 근골격계질환은 산업현장에서 어렵지 않게 발견할 수 있는 신종 산업재해의 일종이다. 특히 미국의 경우, 발생건수와 그로 인한 인적/물적 손실이 급격하게 증가되고 있는 것으로 나타나고 있다. 그러나 미국과 같이 근골격계질환의 폐해를 일찌감치 인식하고 그 해결방안을 연구해온 나라들에서는 현재 환자관리 및 인간공학적인 기준 등을 포함하는 예방지침들이 잘 정착되어 있는 실정이다. 우리나라의 경우에는 작업환경 등의 조건과 상황이 미국과 같은 구미 선전국과 비숫하고, 특히 제조업의 생산체계가 그런 나라들과 매우 유사하여 근골격계질환의 발생과 그로 인한 인적/물적 손실이 적지 않을 것이라고 예상할 수 있지만 아직까지 CTDs에 대한 전반적인 이해가 부족하고, 정확한 실태가 파악되지 못하였으며, 따라서 체계적인 관리 대책 또한 마련되어있지 않은 실정이다. 본 조사에서는 서울 근교의 수송기계관련 사업장의 작업들에 대한 작업자세에 중심을 둔 인간공학평가를 통하여 조사 작업의 근골격계질환에 대한 상대적인 위험도, 위험요인 등을 파악하고, 그에 따른 개선 대책의 방향을 제시하고자 하였다. 특히, 각 부위별 위험점수와 부위별 증상호소율의 상환분석결과, 작업자 개인적 수준에서는 통계적으로 유의한 차는 없는 것으로 분석되었으나, 부서별로 분석한 결과, 작업시 주로 사용하는 오른쪽 상지의 경우, 오른쪽 어깨, 팔꿈치, 손목 순으로 통계적으로 유의하게 관련이 있는 것으로 나타났다. 즉 증상호소율과 해당 신체부위의 위험도 점수는 서로 정적(positive)한 관계에 있는 것으로 나타났고, 상지 중 주로 사용하는 오른쪽 부담의 위험도 자세 점수와 증상호소는 비교적 높은 상관관계에 있는 것으로 나타났다. 따라서 이와 같은 인간공학적 분석결과는 향후 인간공학적인 개선대책의 개발 뿐만 아니라 의학쪽에서 근골격계질환을 접근하는 초기단계에서 매우 유용한 역할을 할 수 있으리라 생각된다.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.589-596
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• 2002

In this paper, setting and strength performances of concrete containing saccharic type super retarding agents are investigated under various kinds and contents of super retarding agents. According to test results, as super retarding agents contents increase, slump shows to be increased, while air contents decrease about 1∼2％. Setting time shows to be retarded considerably with increase of super retarding agents. It takes 20 days after mixing to reach final setting in case of concrete containing gluconic acid more than 0.3％. And 10 days after mixing in case of enhancing sucrose, white and brown sugar. Compressive strength of concrete containing super retarding agents is lower than that of plain concrete at early age. However, it keeps up with and exceeds the compressive strength of plain concrete at later age. White sugar md brown sugar shows positive performances in delaying setting time and strength compared to existing super retarding agents. n further investigations on durability are conducted, it is thought that application of white sugar as super retarding agent is available.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.118-119
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• 2010

star formation is one of the hottest areas in astromy and increasing evidence is showing that star formation is actually a highly dynamic precess driven and strongly influenced by turbulent dynamics of molecular clouds. despite significant progress ir observation in process of star formation, earliest stage of star formation remains imcomplete. so, computer simulations are essential tool since the complex dynamics of star formation. We have performed simulation about the process of low mass star formation using the SPH simulation. we use the dragon-code, the most advanced star formation N-body Smoothed Particle Hydrodynamics (SPH) codes. We present how change the internal properties and how should evolve, while changing the values for Mass turbulence, central density and so on. ( mass range of values is 0.1 < M < $5\;M{\odot}$) based on this results, we discussed their circumstellar, characteristics they were borned and how they will evove while the Birth of low mass stars from interstellar cloud.

• Journal of Korea Game Society
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• v.18 no.1
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• pp.105-114
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• 2018

Various data analysis methods used for customer type analysis are very important for game companies to understand their type and characteristics in an attempt to plan customized content for our customers and to provide more convenient services. In this paper, we propose a k-mode cluster analysis algorithm that uses information uncertainty by extending information entropy to reduce information loss. Therefore, the measurement of the similarity of attributes is considered in two aspects. One is to measure the uncertainty between each attribute on the center of each partition and the other is to measure the uncertainty about the probability distribution of the uncertainty of each property. In particular, the uncertainty in attributes is taken into account in the non-probabilistic and probabilistic scales because the entropy of the attribute is transformed into probabilistic information to measure the uncertainty. The accuracy of the algorithm is observable to the result of cluster analysis based on the optimal initial value through extensive performance analysis and various indexes.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.761-764
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• 2008

The present study is aimed to study the effect of elevated temperatures ranging from 20 to $700^{\circ}C$ on the strain properties of high-strength concrete of 40, 60, 80MPa grade. In this study, the types of test were the stressed test and stressed residual test that the specimens are subjected to a 25% of ultimate compressive strength at room temperature and sustained during heating and when target temperature is reached, the specimens are loaded to failure. Or specimens are loaded to failure after 24hour cooling time. tests were conducted at various temperatures ($20{\sim}700^{\circ}C$) for concretes made with W/B ratios 46%, 32% and 25%. Test results showed that the relative values of elastic modulus decreased with increasing compressive strength grade of specimen and the axial strain at peak stress were influenced by the load before heating. thermal strain of concrete at high temperature was affected by the preload as well as the compressive strength.

• Geotechnical Engineering
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• v.14 no.1
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• pp.93-108
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• 1998

In this study, the analytic solutions and numerical methods were used to estimate the shape and size effects on the stability of underground openings. The stability of underground openings was evaluated by scrutinizing the effects of the rock mass quality, the state of in-situ stresses and the lateral earth pressure coefficient on the displacement, the stress concentration and the plastic region developed in the vicinity of the openings. The analytic solutions have shown that the stress concentration factor is inversely proportional to the radius of curvature of openings. Through parametric study on the various shapes and sizes of underground openings the characteristics of the controlling factors concerned with the stability were analyzed. Then, the study was extended to the horseshoe-shaped openings commonly used for under ground storage. Through the extended study the effects of the stress ratio and the height-towidth ratio of openings on the maximum displacement and plastic region developed around the openings were estimated. The results have shorn that the height-to-width ratio of domestic storage caverns can be increased economically without stability problem, as far as the lateral earth pressure coefficient is appropriate.

• Journal of Families and Better Life
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• v.21 no.2
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• pp.175-185
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• 2003

The purpose of this study was to investigate whether there is any difference between the dual residence couples and the single residence couples in terms of the situation of child care, development of their child and mother's parenting guilty or parenting stress. Also, this study aimed to explore the variables which influence parenting guilty and parenting stress of dual residence mothers. The 178 mothers of three to eight tear-old participated the survey. Half of them were dual residence mothers and another half were those of single residence. These two groups were matched in terms of the occupation of the mother and the age of the child. Major finding were as follows. 1) Compared with single residence couples, dual residence couples used multiple methods of child care. And they depended maternal families more than paternal ones as a care-giver. They also payed much more for the child care than single residence couples. 2) Children of the dual residence couples did not differ with those of the single residence couples in terms of cognitive and social development. 3) Dual residence mothers had more parenting guilty than those of single residence while these two groups did not differ in terms of parenting stress. 4) While dual residence mother's parenting guilty was significantly related with the amount of information provided by the paternal families, their parenting stress was significantly related with the frequencies of communicating with the husband, the mother's age, the flexibility of time in the mother's work place, the mother's orientation to the career, and the supports of the husband. In conclusion, dual residence families in Korea were not so negative as expected. Furthermore, this study suggests that the parenting difficulties of the dual residence mothers could be decreased by the change of social and economic situations and the psycho-social support of the husband.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.411-414
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• 2001

The rapid technical development is changing the environment in the telecommunications industry that is the convergence among technologies, the intensive competition, and so on. Standardization is the core issue in the telecommunications industry, and it is recognized the important strategy to preempt a market by all firms. The telecommunication industry has far-reaching effects to the other industries, so firms in the telecommunications industry compete intensively against one another build on early lead. Because the defeat in standardization competition cause the pertinent nation a great loss. Therefore it shows the intense competition from the early stage in the telecommunications industry. In this paper, we'll examin the change in environment in relation to standardization in the telecommunication and suggest the national policies of standardization.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.140-143
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• 2017

Lately, the three mobile telecom companies in Korea are competing for the launch of internet of things services for using home. Typical launched services are in the smart home related fields. However, internet of things as mobile telecom based are at an early stage, expected that various services will be started continuously. At this point, we have been planning to analyze the preference of Internet of things for objects based on the services already launched. In order to apply the AHP (analytic hierarchy process) analysis method, the first stage factors were designed as safety, security, health care, intelligence and home appliances. In addition, the second stage factors were organized into 18 detailed services presented in the conceptual model. Thus, we present the theoretical and practical implications of these results.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.53-63
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• 2006

Since 2005, the government began to introduce and promote a new project delivery system, BTL(Build, Transfer, and Lease), in order to provide high level of public services for the upgraded quality of life and to boost the domestic and local construction economy. However, the lack of experiences in the new system by the constituents from diverse economic sectors brought a number of drawbacks from each constituent's perspective such as improperly low earning rate, excessive expenses for preparation of the project proposal, imbalanced regulations, heavy cost and procedures to establish SPC, the ineffective structure of the consortium, the short-term oriented evaluation criteria for the selection and so forth. These drawbacks turned out to be obstacles for the successful BTL projects. Hence, this paper analyzes the above issues and conducts the interviews with the professionals from the diverse sectors in order to propose the changes to resolve those for the improvement and finally to deliver the successful BTL projects for the diverse public owners.