• Ocean Systems Engineering
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• 제3권1호
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• pp.35-53
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• 2013

In this study, a hybrid floating structure with cylinder was introduced to reduce the hydrodynamic motions of the pontoon type. The hybrid floating structure is composed of cylinders and semi-opened side sections to penetrate the wave impact energy. In order to exactly investigate the hydrodynamic motions and structural behavior of the hybrid floating structure under the wave loadings, integrated analysis of hydrodynamic and structural behavior were carried out on the hybrid floating structure. Firstly, the hydrodynamic analyses were performed on the hybrid and pontoon models. Then, the wave-induced hydrodynamic pressures resulting from hydrodynamic analysis were directly mapped to the structural analysis model. And, finally, the structural analyses were carried out on the hybrid and pontoon models. As a result of this study, it was learned that the hybrid model of this study was showed to have more favorable hydrodynamic motions than the pontoon model. The surge motion was indicated even smaller motion at all over wave periods from 4.0 to 10.0 sec, and the heave and pitch motions indicated smaller motions beyond its wave period of 6.5 sec. However, the hybrid model was shown more unfavorable structural behavior than the pontoon model. High concentrated stress occurred at the bottom slab of the bow and stern part where the cylinder wall was connected to the bottom slab. Also, the hybrid model behaved with the elastic body motion due to weak stiffness of floating body and caused a large stress variation at the pure slab section between the cylinder walls. Hence, in order to overcome these problems, some alternatives which could be easily obtained from the simple modification of structural details were proposed.

• Journal of the Korea Safety Management & Science
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• 제14권1호
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• pp.137-145
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• 2012

In the previous study, the construction guide line of IT infra-structure for a u-City was introduced. However, it is only concentrated on the components and construction procedure for provider-oriented and technology-oriented sensor networks. In this paper the architecture and building process of demander-oriented sensor networks for sustainable u-City service are proposed. In the paper it is described (1) the enhancement methods of the procedure that can be flexibly constructed according to the scale of the project, (2) the methods that can improve the structure from the wireless sensor network such as RFID/USN to the hybrid sensor network, and (3) the consideration factors for providing the sustainable u-City service.

• Proceedings of the Technology Innovation Conference
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• 기술경영경제학회 2005년도 27회 하계학술발표회 논문집
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• pp.140-158
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• 2005

Science & Technology (S&T) is the most important thing to attain competitiveness in the 21st century. Our traditional S&T policies have been focused on hardware infra structure. But, we should consider soft infra of S&T to enhance welfare development of S&T personnel. S&T should be had a correct understanding method of the creation for S&T culture. It implies that S&T policy in the 21st century should consider non-material factors which include social, human, environment and culture. Under this background. This paper defines the concept of welfare of S&T personnel. Also this paper deals with the change of S&T policy of Korea and analyzes the characteristic of each phase. This paper argues that all actors (for example S&T personnel, corporate using S&T, public) should participate in the process of S&T innovation since the 21st century is the generation of popularization of S&T. The purpose of this paper is to suggest a few methods of welfare improvement of S&T personnel to reinforce soft infra structure of S&T.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 한국주거학회 2011년도 춘계학술발표대회 논문집
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• pp.153-158
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• 2011

According to the change of life environment and economic growth, the more city has highly developed, the more concentrated urban function. That is, city is required for adding infra structure. But, both of limited land resources and financial problems made it impossible to add infra structure. So, the necessity of multi-dimensional planning of urban infra structure was recognized. Especially, In Urban residential area, in order to secure parking area, It is on the increase that mixed-use of the playground of school in the high density area and the empty space of park. School and park is closely connected with town community, playing a central role on town life. For this reason, they are highly demanded for providing space in the urban residential area and also expected to be effective. However, people using park and school are almost young students and the elderly, it needs to consider not only the parking convenience also the safety of users in design process. In this study, we analysed the physical characteristics and the utilization of mixed-use of school and park. and then evaluated the case in the point of convenience and safety. For this, first we selected the case among the sites constructed in seoul, and divided 2type of 'slope type' and 'flatland type'. The meaning of this study is to suggest elementary standards for design in the point of multi-dimensional land use planning.

• Journal of Information Technology Applications and Management
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• 제11권2호
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• pp.65-80
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• 2004

The primary purpose of this study is to investigate ASP (Application Service Provider) vendor attributes that affect ASP client satisfaction. From the relevant literature, ASP vendor attributes that might affect the ASP client satisfaction were derived from which the survey questions were formulated. The survey was conducted among the companies that have adopted ASP. Through the factor analysis of the survey results, the following vendor attributes - vendor's IT infra structure, service reliability, service flexibility, vendor stability, IS maturity, information sharing - were derived ; and the relationships between those attributes and ASP client satisfaction were explored. The result of this study revealed that IT infra, service flexibility, vendor stability are related to ASP client satisfaction. The customer satisfaction factors in the traditional outsourcing -- reliability, IS maturity, information sharing were proved to be not applied in ASP environment. This study provides ASP vendors with guidelines on how to improve their ASP strategies to satisfy clients. The results of this study can also be used by client companies as a decision basis for ASP vendor selection.

• Journal of the Korean Home Economics Association
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• 제42권11호
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• pp.61-84
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• 2004

The purpose of this study is to present foundational data to promote the cultural welfare status of youth. The actual condition of the youth's cultural welfare was investigated by investigating the degree of youth's cultural welfare satisfaction and needs by regional groups. A total of 1486 questionnaires were used for the final data analysis. The analysis revealed the following results. 1. Actual conditions of adolescents cultural welfare. 1) Among various cultural activities, adolescents find leisure and social activity, artistic, mass media and video-media activities very boring and one-sided, Instead, they have greater interest in computer- and Internet-related activities, such as getting and sharing information and communication. 2) While adolescents living in urban areas benefit from well developed social infra-structure, those living in rural areas seldom take advantage of it. 3) The obstacles against cultural welfare of the youth can be categorized as: 'lack of money,' 'lack of time,' and 'lack of cultural facilities. ' In urban areas 'lack of time' becomes an issue, whereas in rural areas 'lack of money' and 'lack of cultual facilities' are important. 2. Degree of cultural welfare satisfaction of the youths. Youths generally appear either 'unsatisfied' or 'neutral' concerning their satisfaction degree about leisure and social activity parts, and art and play-activity paris. On the other hand, they appear 'neutral' concerning their satisfaction degree about computer- and Internet-related information and communication parts, and mass- and video-media activity parts. In addition, urban youths show a higher degree of satisfaction than rural youths. 3. What the youths need To improve their culture welfare status, they need a lot of supplements for cultural activity in the form of cultural infra-structure. Regarding the cultural infra-structure, rural youths need more than urban youths.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.1029-1032
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• 2008

Nowadays, the necessity of the NDT technique for concrete structure has been increased due to maintenance of infra-structure. With this reason, NDT detecting technique has been considered as a effective maintenance method to prevent the rapid degradation of the infra-structure. In this study, to investigate the internal defect of concrete structure, ultrasonic detection device and radar equipment was applied then tested in laboratory and field. In the result of the experimental test, the internal cavity and steel arrangement can be detected and it was possible to adopt the ultrasonic detection method to the maintenance of concrete structure. And an algorithm for performing the maintenance procedure of concrete structure applying ultrasonic detection device and radar equipment was developed and suggested in this study.

• Journal of the Korea Society for Simulation
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• 제19권2호
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• pp.147-155
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• 2010

It often occur to nature disaster that like earthquake, typhoon, etc. around KOREA. A Haiti and Chile also metropolitan area of KOREA occur earthquake. in result, People consider nature disaster. Structures of present age are easily affected by nature disaster. So we are important that warn of dangerous situation as soon as possible. On this study, I introduce Integrated Health Monitoring System for Infra-structure. I develop Structure Health Monitoring System on web-site. Administrator always monitor structure on real-time using internet network. As Administrator using mobile device like PDA, Administrator always monitor structure. As using this system, Damage of nature disaster is minimized and is prevented post damage.

• Journal of the Korean Society for Library and Information Science
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• 제41권4호
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• pp.49-68
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• 2007

To promote information service and to encourage active participation from the group categorized as the alienated class(group of people) this study suggests the basic concepts and strategy for the information services to alienated class who does not have full public library services. The paper classifies three separate groups of alienated groups, handicapped. poor(economically unfortunate group) and elderly group. The service shall consider their needs from their own Point of concern and interests. There are three distinctive considerations, infra structure(facility building, space. place). administrative consideration, and equipments. Infra-structure includes the planning of the space to facilitate the equipments and reference materials which will be control)ed and moderated by a librarian. Administrative service includes the development for the educational system between the end users and external experts. It also includes the individualized education system for each group Material and equipment consideration should include the each group's specific needs such as the infra-structures which is provided for the handicapped person.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.282-286
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• 2000

In this paper, magneto-rheological(MR) damper is studied for vibration control of large infra structures under earthquake. Generally, active control devices need a large control force and a high power supply system to reduce the vibration effectively. Large and miss tuned control force may induce the dangerous situation such that the generated large control force acts to amplify the structural vibration. Recently, to overcome the weaknesses of the active control, the semi-active control method is suggested by many researchers. Semi-active control uses the passive control device of which the characteristics can be modified. Control force of the semi-active device is not generated from the actuator with power supply. It is generated as a dynamic reaction force of the device same as in the passive control case, so the control system is inherently stable and robust. Unlike the case of passive control, control force of semi-active control is adjusted depending on the measured response of the structure, so the vibration can be reduced more effectively against various unknown environmental loads. Magneto-rheological(MR) damper is one of the semi-active devices. Dynamic characteristics of the MR material can be changed by applying the magnetic fields. So the control of MR damper needs only small power. Response time of MR to the input voltage is very short, so the high performance control is possible. MR damper has a high force capacity so it is adequate to the vibration control of large infra structure. Because MR damper has a nonlinear property, normal control method used in active control may not be effective. Clipped optimal control, modified bang-bang control etc. have been suggested to MR damper by many researchers. In this study, sliding mode fuzzy control(SMFC) is applied to MR damper. Genetic algorithm is used for the controller tuning. To verify the applicability of MR damper and suggested algorithm, numerical simulation on the aseismic control is carried out. Simulation model is three-story building structure, which was used in the paper of Dyke, et al. The control performance is compared with clipped optimal control. The present results indicate that the SMFC algorithm can reduce the earthquake-induced vibration very effectively.