• 전기학회논문지
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• 제56권1호
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• pp.66-70
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• 2007

For the design to prevent the saturation of the iron core and the effective fault current limitation, the analysis for the operation of the flux-lock type superconducting fault current limiter (SFCL) with consideration for the hysteresis characteristics of the iron core is required. In this paper, the hysteresis characteristics of the flux-lock reactor, which is an essential component of the flux-lock type SFCL, were investigated. Under normal condition, the hysteresis loss of the iron core in the flux-lock type SFCL does not happen due to its winding structure. From the equivalent circuit for the flux-lock type SFCL and the fault current limiting experiments, the hysteresis curves could be drawn. From the analysis for both the hysteresis curves and the fault current limiting characteristics due to the number of turns for the 1st and 2nd windings, the increase of the number of turns in the 2nd winding of the flux-lock type SFCL had a role to prevent the iron core from saturation.

• 한국안전학회지
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• 제13권4호
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• pp.102-112
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• 1998

Shock absorber has a great influence on the performance of the vehicle(ride comfort, manipulation, noise, vibration, turning, stability). Therefore, in this study we consider theoretically about general damper, variable damping oil damper, the control of vehicle Characteristics for the suspension, and undesirable phenomenon. And we measured the vibration/noise characteristics of shock absorber for the real car experimentation, strain change, and noise characteristics of shock absorber using experimental equipment. The study of domestic company and research institute on the vehicle shock absorber is active, but that of basis is not. So we think that they should be accomplished actively. Therefore, this paper will develop theoretical system on the vibration/noise characteristics of shock absorber by theoretical consideration and experimental result analysis of dynamic characteristics of shock absorber that were accomplished in this study. Then we will use it as the optimistic design data for shock absorber development.

• 대한물리치료과학회지
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• 제10권2호
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• pp.163-172
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• 2003

Background and Purpose. Physical therapists are at risk for work-related musculoskeletal disorders (WMSDs). Little understand the characteristics of work in physical therapist or the effort they take to prevent injury. The purpose of this study was to investigate the characteristics of work in physical therapist and the efforts for prevent injury Subjects. Standardized questionnaire was administered to 103 physical therapist in Pusan association. Methods. An questionnaire was given to each subject. Questions investigated the characteristics of work in physical therapist, efforts and caring of injury prevention. Chi-square Test used to assess the association of general characteristics with the characteristics of work in physical therapist. AVONA and T-test used to assess the association of efforts of prevent injury in independent variable Results. Physical therapist was reported a higher prevalence of WMSDs in most body areas. These attributes sometimes resulted in behaviors that contributed to the development of their WMSDs.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권1호
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• pp.15-20
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• 2004

This paper discusses electrical insulation characteristics at cryogenic temperature, especially focusing on partial discharge (PD) inception characteristics, for high temperature superconducting cables. In liquid nitrogen (L$N_2$) / polypropylene (PP) laminated paper composite insulation system, PD inception strength (PDIE) was evaluated in terms of volume effect and V-t characteristics. Different kinds of butt gap condition were applied in the experiments, using parallel plane and coaxial cylindrical cable samples. Experimental results revealed that the volume effect on PDIE could be evaluated by the statistical stressed liquid volume (SSLV) taking account the discharge probability not only in the butt gap but also in the other thin layers between PP laminated papers. Furthermore, the indices n of V-t characteristics at PD inception were estimated to be 80∼110, irrespective of the butt gap condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.684-686
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• 2001

A Bi-2223 tape has been developed for power applications such as power cables or transformers working at liquid nitrogen temperature. For such applications it is required to understand fault current characteristics of the Bi-2223 tape. In this paper, we report fault current characteristics using two types of samples, straight sample and pancake coil sample. It was found that the fault current characteristics of the Bi-2223 tape are depend on electrical insulations and fault durations strongly. Also it was shown that the fault current characteristics in the insulated straight sample are similar to those in the pancake sample with a conductor insulation. Finally, it was shown that the pancake sample with a layer insulation has better characteristics than that with a conductor insulation for fault currents.

• 한국철도학회논문집
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• 제5권1호
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• pp.26-31
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• 2002

The more sophisticated patterns of propagation model is presented in this paper, which includes three different source characteristics (spherical, cosine and dipole). The spherical, cosine and dipole radiation characteristics compared, and sound event level and the maximum sound level are calculated by experiment and calculation. It is shown that patterns of propagation have dipole characteristics for low speed range (below about 150Km/h) at electric multiple system. We know that push-pull high speed system has cosine characteristics of noise propagation at low speed range (below about 200Km/h).

• Tribology and Lubricants
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• 제29권1호
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• pp.39-45
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• 2013

Magnetorheological (MR) fluid belongs to the group of smart materials. In MR fluid, iron particles in base oil form chains in the direction of the applied magnetic field, thus resulting in a variation in the stiffness and damping characteristics of the fluid. Research is being carried out on controlling the stiffness and damping characteristics as well as the tribological characteristics of the MR fluid. In this study, the friction characteristics of MR fluid have been evaluated using three types of materials and magnetic fields of different strengths. The coefficients of friction of the three types of MR fluid are measured, and the relationship between the coefficient of friction and the strength of the applied magnetic field is obtained.

• 건축역사연구
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• 제7권4호
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• pp.93-102
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• 1998

There are several treatises about architectural characteristics of Hyangkyo. But those treatises usually treat with the types of site plans or structural characteristics without the historic background. So there needs the approaching methods with the historic background to study about the architecture of Hyangky. This study aims at the sample research about the architecture of Hyangkyo in beginnig period. Kyodong hyangkyo is the first building in hyangkyo. There are some architectural characteristics in this building comparing with the Hyangkyo in ripening period. Such characteristics apper in the site plan of educational spaces and in the floor plans of Myongryundang, Dongjae, Seojae. And there appear some characteristecs in ritual spaces such as the architectural structure of Daesungjun, and the position of stone establishment (Kwansedae, Saengdan) The ritual form of Kyodong hyangkyo has no special characteristics compering with the Hyangkyo in ripening period. These rictual form has kept the general rule of ritura form through the history.

• 한국보육지원학회지
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• 제14권3호
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• pp.97-115
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• 2018

Objective: This study aimed to analyse the influence of young children's playfulness at home and class characteristics on their playfulness at kindergarten. Methods: Twenty eight classes of 3, 4 and 5 year olds in Gyeonggi and Chungbuk provinces were recruited. Participants of this study were mothers and head teachers of the children of recruited classes. Analyses was implemented using hierarchical linear modeling with HLM 7.0. Results: Differences were found in children's playfulness at kindergarten according to their classes. Individual characteristics including, gender, age and playfulness at home were shown to have significant influences on playfulness at kindergarten, while relevance of variable class characteristics to playfulness at kindergarten was not observed. Conclusion/Implications: It is concluded that playfulness of children is more related to playfulness at home rather than class characteristics, implying the strong characteristic of playfulness as an individual trait.

• 한국공간구조학회논문집
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• 제2권3호
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• pp.71-79
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• 2002

The purpose of this paper is to study the buckling characteristics of elliptical latticed domes under conservative loading conditions. The latticed domes are usually designed in geometrically spherical shape. For this type of latticed domes, many researchers have researched and even the simplified estimation codes for the buckling load level have been available. However, geometrically elliptical latticed domes have been often constructed, and show different buckling characteristics following with geometrical parameters as rise-to-span ratio and so on. Therefore, it is necessary to investigate the general tendency of buckling characteristics of the elliptical latticed domes. In this paper, to find out some buckling characteristics of elliptical latticed domes, height, boundary configuration and gap are used as the shape coefficients. For each model with different parameters, the eigen values and the buckling loads are evaluated.