• Journal of the Korean Society of Physical Medicine
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• v.12 no.3
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• pp.23-32
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• 2017

PURPOSE: Flexibility and range of motion are very important factors in sports performance, rehabilitation, and musculoskeletal pain. The purpose of this study was to measure the effects of cupping therapy on flexibility, muscle activity, and pain threshold of hamstring muscle compared to passive stretching in healthy subjects. METHODS: Thirty healthy subjects were randomly assigned in a crossover design to cupping therapy and passive stretching. Subjects were tested to compare their effects according to the intervention such as Passive range of motion (PROM) (straight leg raising) and active range of motion (AROM). And algometer (pain) testing and MVC assessment using EMG were performed as dependent variables. RESULTS: The cupping therapy group and passive stretching group showed significant differences in all variables including PROM (p=.00, p=.00), AROM (p=.00, p=.03), Pain Threshold (p=.03, p=.08), Semitendinosus MVC (p=.01, p=.00), and Biceps femoris MVC (p=.01, p=.16). There were no significant differences between the two groups in all variables. CONCLUSION: These findings of this study suggested that cupping therapy has as much positive effect on flexibility, pain threshold, and muscle contraction as passive stretching. Also, it is more convenient and easier to work on patients than passive stretching. Therefore, cupping therapy should be considered as another option to treat range of motion, pain, and muscle activity in the clinical field.

• Korean Journal of Human Ecology
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• v.16 no.2
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• pp.285-298
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• 2007

The purpose of this study is to find out specific ways to invigorate the employment of the elderly. To achieve this goal, attitude and information about elderly employment were required, and the groups divided based on them were found. The results of the research are as follows: 1. Attitudes toward employment of the elderly was considerably positive. Among the attitudes, the attitude toward employment-support was the most positive, and the attitude toward employment-motive was relatively less positive. 2. The extent the elderly possessed information about employment was comparatively limited, and quite a low score was shown in knowledge of employment-information of the elderly, which means the elderly are not exposed to the ways to get employed. 3. The groups were divided in four type: passive-stagnation, positive-adjustment, lack of information-work oriented, retirement oriented. Of the employed, the positive-adjustment were the most and the passive-stagnation were the least, while the lack of information-work oriented were the most and the retirement oriented were the least of the unemployed. The result that the lack of information-work oriented were the most of the unemployed shows the choice of unemployment was not an intended one.

• Geomechanics and Engineering
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• v.15 no.1
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• pp.621-630
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• 2018

In the note a comprehensive and optimal passive-active mode for describing the limit failure of circular shallow tunnel with settlement is put forward to predict the catastrophic stability during the geotechnical construction. Since the surrounding soil mass around tunnel roof is not homogeneous, with tools of variation calculus, several different curve functions which depict several failure shapes in different soil layers are obtained using virtual work formulae. By making reference to the simple-form of Power-law failure criteria based on numerous experiments, a numerical procedure with consideration of combination of upper bound theorem and stochastic medium theory is applied to the optimal analysis of shallow-buried tunnel failure. With help of functional catastrophe theory, this work presented a more accurate and optimal failure profile compared with previous work. Lastly the note discusses different effects of parameters in new yield rule and soil mechanical coefficients on failure mechanisms. The scope of failure block becomes smaller with increase of the parameter A and the range of failure soil mass tends to decrease with decrease of unit weight of the soil and tunnel radius, which verifies the geomechanics and practical case in engineering.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.500-509
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• 2009

Passive samplers have been used for many years for the sampling of organic vapors in work environment atmospheres. Currently, all passive samplers used in domestic occupational monitoring are foreign products. This study was performed to evaluate variable parameters for the development of passive organic samplers, which include the geometry of the device and diffusive length for the sampler design. Four prototype diffusive lengths; A-1(4.5 mm), A-2(7.0 mm), A-3(9.5 mm), A-4(12.0 mm) were tested for adsorption performances to a chemical mixture (benzene, toluene, trichloroethylene, and n-hexane) according to the US-OSHA's evaluation protocol. A dynamic vapor exposure chamber developed and verified by related research was used for this study. The results of study are as follows. The results in terms of sampling rate and recommended sampling time test indicate that the most suitable model was A-3 (9.5 mm diffusive lengths on both sides) for passive sampler design in time weighted average (TWA) assessment. Sampling rates of this A-3 model were 45.8, 41.5, 41.4, and 40.3 ml/min for benzene, toluene, trichloroethylene, and n-hexane, respectively. The A-3 models were tested on reverse diffusion and conditions of low humidity air (35% RH) and low concentrations (0.2 times of TLV). These conditions had no affect on the diffusion capacity of samplers. In conclusion, the most suitable design parameters of passive sampler are: 1) Geometry and structure - 25 mm diameter and 490 $mm^2$ cross sectional area of diffusion face with cylindrical form of two-sided opposite diffusion direction; 2) Diffusive length - 9.5 mm in both faces; 3) Amount of adsorbent - 300 mg of coconut shell charcoal; 4) Wind screen - using nylon net filters (11 ${\mu}m$ pore size).

• Journal of Navigation and Port Research
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• v.27 no.3
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• pp.267-272
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• 2003

This paper describes design method of Passive-type Radar Reflector (PRR) which is to provide the requirement of newly revised 2000 SOLAS regulations on the Radar Reflector. The main target of this work is to find the optimum shape of a radar target having large Radar Cross Section (RCS). Through the RCS analysis based on the theoretical approach, two kinds of PRR models, RRR-F model for use in fisheries and PRR-S model for use in small sized ship, are designed and discussed their RCS performance. RCS measurement tests for the various sized samples are carried out in an anechoic chamber. As evaluation results it was clearly shown that the conventional sphere-type shows optimum shape in case of PRR-S, while the cylinder-type which consists of large sized corner clusters or zig-zag flat plats gives best performance in case of PRR-F.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.5 s.236
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• pp.707-715
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• 2005

In this work, Scalar Passive code in Lattice Boltzmann Method is employed to simulate two-phase flow of low Reynolds number in a micro-channel. The mixing characteristics in a micro-channel is a function of Peclet number. The mixing length increases with the Peclet number. It is found that with the inclusion of static elements at the channel, rapid mixing of two liquids can be achieved, as shown by the results of computer simulations. The enhancement in mixing performance is thought to be caused by the generation of eddies and by lateral velocity component when the mixture flows past static elements. The results indicate that the size of static element has more effect on the mixing than the number of static element.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.1941-1948
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• 2004

This paper presents a novel design of indoor airship having a passive wheeled mechanism and its stationary position control. This wheeled blimp can work both on the ground using wheeled vehicle part and in the air using the floating capability of the blimp part. The wheeled blimp stands on the floor keeping its balance using a caster-like passive wheel mechanism. In tele-guidance application, stationary position control is required to make the wheeled blimp naturally communicate with people in standing phase since the stationary blimp system responds sensitively to air flow even in indoor environments. To control the desired stationary position, a computed torque control method is adopted. By performing a controller design through dynamic analysis, the control characteristics of the wheeled blimp system have been found and finally the stable control system has been successfully developed. The effectiveness of the controller is verified by experiment for the real wheeled blimp system.

• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.66-82
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• 1999

The national long-term R&D program, updated in 1997, requires Korea Atomic Energy Research Institute(KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor(KALIMER), along with supporting R&D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 MWe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self-consistent design meeting a set of major safety design requirements for accident prevention. Some of the current emphasis includes those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve extensive supporting R&D programs. This paper summarizes some of the results of conceptual engineering and design analyses performed for the safety of HAMMER in the area of inherent safety, passive decay heat removal, sodium water reaction, and seismic isolation.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.406-411
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• 2005

In this paper, we propose an active 90$^{\circ}$ phase divider for application to MMIC. Because of their very large size, conventional passive 90$^{\circ}$ dividers can't be integrated on MMIC. Therefore, highly miniaturized 90$^{\circ}$ dividers are required for a development of highly integrated MMIC. For this reason, active 90$^{\circ}$ divider is indispensable because active phase divider is much smaller than conventional passive dividers, and it can be integrated on MMIC. In this work, we developed active 90$^{\circ}$ divider with emitter inductor, and it was employed for the operation of the balanced mixer in order to verify the performance of the active 90$^{\circ}$ divider. According to the results, it was found that the active 90$^{\circ}$ divider exhibited good RF performances comparable to conventional passive power dividers.

• Advances in aircraft and spacecraft science
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• v.3 no.3
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• pp.299-315
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• 2016

In this work, a strategy for passive vibration control of periodic structures is proposed which involves adding a periodic array of simple resonant devices for creating band gaps. It is shown that such band gaps can be generated at low frequencies as opposed to the well known Bragg scattering effects when the wavelengths have to meet the length of the elementary cell of a periodic structure. For computational purposes, the wave finite element (WFE) method is investigated, which provides a straightforward and fast numerical means for identifying band gaps through the analysis of dispersion curves. Also, the WFE method constitutes an efficient and fast numerical means for analyzing the impact of band gaps in the attenuation of the frequency response functions of periodic structures. In order to highlight the relevance of the proposed approach, numerical experiments are carried out on a 1D academic rod and a 3D aircraft fuselage-like structure.