• 대한정형도수물리치료학회지
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• 제19권2호
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• pp.55-60
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• 2013

Background: The purpose of this study was to determine if there is a difference in activation of the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris when performing normal free squat with standinding position and free squat with $30^{\circ}$ flexed hip joint. Methods: Electromyograph surface electrodes were placed on the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris of 19 healthy college students. The participants performed standing bilateral squats and standing bilateral squats with $30^{\circ}$ flexed hip joint with EMG measures taken upon initiation of muscle activity as confirmed by an electronic goniometer. Participants completed one trial with the EMG time measurements on each type. Results: There was a significant difference between normal squats(standing squats) and normal squats with $30^{\circ}$ flexed hip joint. The normal squat exercise was statistically higer than normal squat exercise with $30^{\circ}$ flexed trunk except for semitendinosus and biceps femoris that shown slightly high. Conclusions: As a result of this study, there were increases of muscle activity in both ways. In particular, it may be more beneficial for knee joint stabilization to perform normal squat exercise with standing position relatively.

• 한국전산유체공학회지
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• 제4권1호
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• pp.19-26
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• 1999

This paper describes a numerical method for predicting the incompressible unsteady laminar three-dimensional flows with free-surface. The Navier-Stokes equations governing the flows have been discretized by means of finite-difference approximations, and the resulting equations have been solved via the SIMPLE-C algorithm. The free-surface is defined by the motion of a set of marker particles and the interface behaviour was investigated by means of a "Lagrangian" technique. Using the GALA concept of Spalding, the conventional mass continuity equation is modified to form a volumetric or bulk-continuity equation. The use of this bulk-continuity relation allows the hydrodynamic variables to be computed over the entire flow domain including both liquid and gas regions. Thus, the free-surface boundary conditions are imposed implicitly and the problem formulation is greatly simplified. The numerical procedure is validated by comparing the predicted results of a periodic standing waves problems with analytic solutions. The results show that this numerical method produces accurate and physically realistic predictions of three-dimensional free-surface flows.

• 대한치과의사협회지
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• 제28권7호통권254호
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• pp.641-648
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• 1990

• 한국지능시스템학회논문지
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• 제21권6호
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• pp.673-678
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• 2011

본 논문에서는 물체의이동이나 정보 탐색을위하여 유용하게 사용될 수 있는 4족 로봇의 정지 밸런스를 분석하고자 한다. 이 목적을위하여, 일반적인 4족 로봇의유용한 모델을 제시하고, 정지 안정성을 고려한 경계 조건을 제안한다. 착지된 상태에서 4족 로봇의 정지 밸런스를 분석하기 위하여 다양한 자유 운동을 고려하며, 시뮬레이션을 통하여 밸런스 여유를 고찰한다. 이러한 분석은 4족 로봇 보행의 효과적인 밸런싱 제어를 위하여 유용하게 활용될 수 있을것이다.

• 대한기계학회논문집
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• 제19권5호
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• pp.1319-1332
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• 1995

Numerical analysis was performed to characterize the particle deposition behavior on a horizontal free-standing wafer with thermophoretic effect under the turbulent flow field. A low Reynolds number k-.epsilon. turbulence model was used to analyze the turbulent flow field around the wafer, and the temperature field for the calculation of the thermophoretic effect was predicted from the energy equation introducing the eddy diffusivity concept. The deposition mechanisms considered were convection, diffusion, sedimentation, turbulence and thermophoresis. For both the upper and lower surfaces of the wafer, the averaged particle deposition velocities and their radial distributions were calculated and compared with the laminar flow results and available experimental data. It was shown by the calculated averaged particle deposition velocities on the upper surface of the wafer that the deposition-free zone, where the deposition velocite is lower than 10$^{-5}$ cm/s, exists between 0.096 .mu.m and 1.6 .mu.m through the influence of thermophoresis with positive temperature difference of 10 K between the wafer and the ambient air. As for the calsulated local deposition velocities, for small particle sizes d$_{p}$<0.05 .mu.m, the deposition velocity is higher at the center of the wafer than at the wafer edge, whereas for particle size of d$_{p}$ = 2.0 .mu.m the deposition takes place mainly on the inside area of the wafer. Finally, an approximate model for calculating the deposition velocities was recommended and the calculated deposition velocity results were compared with the present numerical solutions, those of Schmidt et al.'s model and the experimental data of Opiolka et al.. It is shown by the comparison that the results of the recommended model agree better with the numerical solutions and Opiolka et al.'s data than those of Schmidt's simple model.

• 한국주거학회논문집
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• 제13권6호
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• pp.111-120
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• 2002

The purpose of this study is to understand the trends of urban housing in the age of modernization in Western cities since 1970's, and to provide the useful data for diversifying urban housing types in Korea. Although the housing types can be categorized in many ways according to the points of view, this study classifies 11 types by a criterion of urban composition elements. Among 11 urban housing types, one type, free-standing slab structure, has been mainly applied to Korean situation. The reason might be that the free-standing structure type is the most efficient one in terms of land use and block organization, but it results in a monotonic condition of urban housing blocks. Therefore, taking local characteristics and urban contexts in Korea into consideration, the future urban housing design should be developed in different ways of making local life styles possible in them, by adopting various types of Western urban housing precedents.

• Structural Engineering and Mechanics
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• 제23권3호
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• pp.309-323
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• 2006

In this paper, seismic response of a free-standing ship located in a dry dock and supported by an arrangement of n keel blocks due to base excitation is addressed. Formulation of the problem including derivation of governing equations in various modes of motion as well as transition conditions from one mode to another is given in Moghaddasi and Bargi (2006) by same authors. On the base of numerical solution for presented formulation, several numbers of analyses are conducted to study sensitivity of system's responses to some major contributing parameters. These parameters include friction coefficients between contacting surfaces, block dimensions, peak ground acceleration, and the magnitude of vertical ground acceleration. Finally, performance of a system with usual parameters normally encountered in design is investigated.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.67-74
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• 1998

Two kinds of polished and unpolished freestanding films prepared by DC plasma CVD method were impacted by SiC particles to understand erosion mechanism. Erosion damage caused by solid impact was characterized by surface profilometer, scanning electron microscopy and Raman spectroscopy. Gradually decrease of surface roughness and sharp reduction of crystallinity for unpolished CVD films were observed with increasing erosion time. It was found that smaller grains of the diamond were removed in early stage of erosion process and larger grains were eroded with further impingement. By introduction of re-growth method on polished diamond, further understanding of erosion mechanism was achieved. Most of the surface fractures were initiated at the grain boundary.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1107-1108
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• 2006

The coating of conductive polypyrrole (Ppy) on nonconductive ceramic substrates was performed by polymerization of pyrrole (Py) in an aqueous solution. The Ppy film was characterized by scanning electron microscopy and conductivity measurements. Electrophoretic deposition of bimodal alumina suspension prepared with a phosphate ester was performed using Ppy film as a cathode. Fabrication of alumina ceramics with irregular shapes or complicated patterns were also attempted by sintering the deposits together with the Ppy coated substrates in air.

• 보건행정학회지
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• 제2권2호
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• pp.152-178
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• 1992

This study focuses on making recommendations for the improvement of poor emergency medical services or EMS in Korea. Problems of the current EMS system is widely reviewed. As an alternative of the current system, a franchises system is introduced to EMS. A feasibility study of the new system is carried out as follows. 1) The current EMS system shows such problem as; - Inadequacy of emergency medical fee schedule, - Shortage of emergency medical resources, - Concentration of emergency medical facilities in metropolitan area, - Unestablishment of training program for emergency personnel, - Inappropriateness of patients' behvaviro pattern in emergency care system. 2) Recommendations for the improvement of EMS are as follows: - Well organized communication and transportation system needs to be established by utilizing all the availabl EMS is to be devised for the provision of appropriate emergency care. - A franchises system can be widly adopted so that private organizations are willing to establish a free standing emergency center. - Emergency care fee schedule of the franchises system needs to be appropriate for the system to provide high standard medical services.