• 한국표면공학회지
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• 제34권5호
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• pp.395-402
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• 2001

An induction thermal plasma system have been newly designed for advanced operation with a pulse modulated mode to control the plasma power in time domain and to create non-equilibrium effects such as fast quenching of the plasma to produce new functional materials in high rate. The system consists of MOSFET power supply with a maximum power of 50 kW with a frequency of 460 kHz, an induction plasma torch with a 10-turns coil of 80 mm diameter and 150 mm length and a vacuum chamber. The pulse modulated plasma was successfully generated at a plasma power of 30 kW and a high pressure of 100 kPa, with taking the on and off time as 10 ms, respectively. Measurements were carried out on the time-dependent spectral lines emitted from Ar species. The dynamic behavior of plasma temperature in a pulse cycle was estimated by the Boltzmann plot and the excitation temperature of Ar atom was found to be changed periodically from around 0.5 to 1.7 eV during the cycle. Two application regions of the induction thermal plasma newly generated were introduced to material processing with high rate synthesis based on non equilibrium effects, and to the finding of new arc quenching gases coming necessary for power circuit breaker, which is friendly with earth circumstance alternative to SF6 gas.

• Journal of Korean Biological Nursing Science
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• 제19권3호
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• pp.151-157
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• 2017

Purpose: The purpose of this study was to identify the effects of hand and foot baths on sleep and body temperature of the elderly. Methods: The research was designed for a nonequivalent control group before and after the test design. The subjects of this study totaled 43, aged 65 and over (23 people in hand bath group and 20 people in a foot bath group), who received a written voluntary consent to participate in experimental treatment and are in the W care center, S Nursing Home, and H care center in Seoul. Data were collected with questionnaires and observations, and were analyzed on the basis of frequency, percentage, mean, standard deviation, ${\chi}^2-test$, Fisher exact test, t-test and paired t-test. Results: There are no significant differences in homogeneity test of a dependent variable between groups (hand bath, foot bath). The differences between 2 groups on the sleep quality score and systolic blood pressure, diastolic blood pressure temperature were not significant statistically except on the pulse. Conclusion: Based on the results of this study, hand bath is as efficient as foot bath. Therefore, a hand bath can be a nursing intervention in order to enrich sleep quality for the elderly because a hand bath is more convenient than foot bath.

• 대한물리의학회지
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• 제12권3호
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• pp.43-47
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• 2017

PURPOSE: The purpose of this study was to identify the effects of physical therapy plus Kinesio taping (KT) on muscle tone and stiffness in patients with shoulder pain. METHODS: This study included 22 participants who were divided into the experimental group (n=11) who underwent a routine physical therapy with KT and the control group (n=11) who received the same physical therapy only. The physical therapy consisted of heat application and electrical stimulation. Heat was applied for 10 minutes and electrical stimulation was conducted for 20 minutes. Intervention was provided over a 1-week period, and frequency for muscle tone and stiffness was measured to determine changes in shoulder muscle status. The muscles were supraspinatus and deltoid. Measurements were taken before, after 1day, 3day and after 1 week to identify time-dependent effects of intervention. RESULTS: The effects of the intervention were significant in both groups, and effects were greater in the experimental group. Changes in muscle tone and stiffness were statistically significant in both groups and at varying time points (p<.05). CONCLUSION: Based on the improved muscle performance found in this study, KT is considered an effective intervention strategy for patients with shoulder pain when it is combined with conventional physical therapy.

• Smart Structures and Systems
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• 제14권6호
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• pp.1221-1245
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• 2014

Real-time hybrid simulation (RTHS) is a promising cyber-physical technique used in the experimental evaluation of civil infrastructure systems subject to dynamic loading. In RTHS, the response of a structural system is simulated by partitioning it into physical and numerical substructures, and coupling at the interface is achieved by enforcing equilibrium and compatibility in real-time. The choice of partitioning parameters will influence the overall success of the experiment. In addition, due to the dynamics of the transfer system, communication and computation delays, the feedback force signals are dependent on the system state subject to delay. Thus, the transfer system dynamics must be accommodated by appropriate actuator controllers. In light of this, guidelines should be established to facilitate successful RTHS and clearly specify: (i) the minimum requirements of the transfer system control, (ii) the minimum required sampling frequency, and (iii) the most effective ways to stabilize an unstable simulation due to the limitations of the available transfer system. The objective of this paper is to establish a stability switch criterion due to systematic experimental errors. The RTHS stability switch criterion will provide a basis for the partitioning and design of successful RTHS.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.200-200
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• 2003

Polycrystalline Si(polysilicon) TFTs have opened a way for the next generation of display devices, due to their higher mobility of charge carriers relative to a-Si TFTs. The polysilicon W applications extend from the current Liquid Crystal Displays to the next generation Organic Light Emitting Diodes (OLED) displays. In particular, the OLED devices require a stricter control of properties of gate oxide layer, polysilicon layer, and their interface. The polysilicon layer is generally obtained by annealing thin film a-Si layer using techniques such as solid phase crystallization and excimer laser annealing. Typically laser-crystallized Si films have grain sizes of less than 1 micron, and their electrical/dielectric properties are strongly affected by the presence of grain boundaries. Impedance spectroscopy allows the frequency-dependent measurement of impedance and can be applied to inteface-controlled materials, resolving the respective contributions of grain boundaries, interfaces, and/or surface. Impedance spectroscopy was applied to laser-annealed Si thin films, using the electrodes which are designed specially for thin films. In order to understand the effect of grain size on physical properties, the amorphous Si was exposed to different laser energy densities, thereby varying the grain size of the resulting films. The microstructural characterization was carried out to accompany the electrical/dielectric properties obtained using the impedance spectroscopy, The correlation will be made between Si grain size and the corresponding electrical/dielectric properties. The ramifications will be discussed in conjunction with active-matrix thin film transistors for Active Matrix OLED.

• 한국공작기계학회논문집
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• 제14권3호
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• pp.87-95
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• 2005

The object of this study is to investigate the effect of joinability by using acoustic emission(AE) signals and doing a pattern recognition for weld heat affected zone(HAZ) in tensile testing. This study was carried out an SWS 490A high tension steel for electric shielded metal arc welding(SMAW), $CO_2$ gas arc welding and TIG welding. And correspondingly, the root openings are 3, 4 and 2.8mm. The results of the tensile test of weld HAZ come out electric shield arc welding $>\;CO_2$ gas arc welding > TIG welding in case of single welding. It is believed that this is a phenomenon where difference of its root opening or base metal thickness. Also, the technique of AE is ideally suited to study variables which control time and stress dependent fracture or damage process in metallic materials.

• 열처리공학회지
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• 제29권4호
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• pp.176-180
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• 2016

In this study, a microstructural investigation was conducted on the cracking phenonmenon occurring during hot rolling of Fe-23Mn high-manganese steels with different aluminium and carbon contents. Particular emphasis was placed on the phase stability of austenite and ferrite dependent on the chemical composition. An increase in the aluminum content promoted the formation of ferrite band structures which were easily deformed or cracked. In the steels containing high carbon contents of 0.4 wt.% or higher, on the other hand, the volume fraction and thickness of ferrite bands decreased and thus the cracking frequency was significantly reduced. Based on these findings, it is said that the microstructural evolution occurring during hot rolling of high-manganese steels with different aluminium and carbon contents plays an important role in the cracking phenomenon. To prevent the cracking, therefore, the formation of second phases such as ferrite should be minimized during the hot rolling by the appropriate control of the chemical composition and process parameters

• Journal of Preventive Medicine and Public Health
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• 제23권2호
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• pp.178-184
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• 1990

In order to examine the mutagenicity of cadmium dichloride the author studied the induction of sister chromatid exchanges in chinese hamster ovary $K_1$ cells which treated with cadmium dichloride at various concentrations. The results obtained were as follows : 1. In cells treated with $10^{-4}M$ cadmium dichloride, a small number of cells were viable but no mitosis was bound. 2. The frequencies of sister chromatid exchanges in cells treated with $10^{-5}M\;and\;10^{-6}M$ cadmium dichloride as $10.7{\pm}1.9\;and\;8.3{\pm}2.1$, respectively, were significantly increased for control ($6.0{\pm}2.3$). (P<0.05). 3. There were dose-dependent relationship between the concentration of cadmium dichloride and frequency of sister chromatid exchanges in cells treated with cadmium dichloride at concentration ranging from $10^{-5}\;to\;10^{-7}M$.

• 한국소음진동공학회논문집
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• 제16권7호
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• pp.754-761
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• 2006

This paper presents the dynamic characteristics of MR impact damper for vehicle collision system. Various types of mechanism have been proposed to reduce force transmitted to the vehicle chassis and finally to protect occupants from injury. In the case of head-on collision, the bumper makes main role of isolation material for collision attenuation. In this study, the proposed bumper system consists of MR impact damper and structures. The MR impact damper utilizes MR fluid which has reversible properties with applied magnetic field. The MR fluid operates under flow mode. The bellows is used for generation of fluid flow. A mathematical model of the MR impact damper is derived incorporating with Bingham model of the MR fluid. Field dependent damping force is investigated with time and frequency domain. The MR impact damper is then incorporated with vehicle crash system. The governing equation of motion of vehicle model is formulated considering occupant model. Dynamic characteristics of vehicle collision system investigated with computer simulation.

• 성인간호학회지
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• 제24권3호
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• pp.253-265
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• 2012

Purpose: The focus of this research was a systematic review of published articles and theses for a degree in Korea and foreign countries on rehabilitation therapy for patients with total knee arthroplasty (TKA). Methods: The literature until December in 2011 were searched and the data basis included Medline, CINAHL, KERIS, National Library of Korea, and National Assembly Library web sites. Words for the search were TKA or TKA and rehabilitation. Studies included randomized controlled and non-equivalent control group pretest-posttest design. 31 studies were analyzed focusing on type, application method, dependant variable and effect using descriptive statistics. Results: Seventeen rehabilitation therapies and forty-nine dependant variables were used. The application methods of rehabilitation therapy were diverse. The most frequently used rehabilitation type was an exercise therapy and a pain/discomfort was the most frequently used dependant variable. The effects of rehabilitation therapy were inconsistent. Conclusion: The individualized rehabilitation therapy must be comprised of type, time, frequency, period and duration. Attention must be made as to the research design, especially the better measurement of the dependent variables. This review may serve as a base for future research.