• Journal of applied mathematics & informatics
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• 제32권3_4호
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• pp.389-403
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• 2014

In this paper, we first provide comparison results of preconditioned AOR methods with direct preconditioners $I+{\beta}L$, $I+{\beta}U$ and $I+{\beta}(L+U)$ for solving a linear system whose coefficient matrix is a large sparse irreducible L-matrix, where ${\beta}$ > 0. Next we propose how to find a near optimal parameter ${\beta}$ for which Krylov subspace method with these direct preconditioners performs nearly best. Lastly numerical experiments are provided to compare the performance of preconditioned iterative methods and to illustrate the theoretical results.

• The Journal of Korean Physical Therapy
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• 제22권6호
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• pp.91-98
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• 2010

Neurostimulation approaches have been developed and explored to modulate neuroplastic changes of cortical function in human brain. As one of the most primary noninvasive tools, transcranial direct current stimulation (tDCS) was extensively studied in the field of neuroscience. The alternation of cortical neurons depending on the polarity of the tDCS has been used for improving cognitive processing including working memory, learning, and language in normal individuals, as well as in patients with neurological or psychiatric diseases. In addition, tDCS has great advantages: it is a non-invasive, painless, safe, and cost-effective approach to enhance brain function in normal subjects and patients with neurological disorders. Numerous previous studies have confirmed the efficacy of tDCS. However, tDCS has not been considered for clinical applications and research in the field of physical therapy. Therefore, this review will focus on the general principles of tDCS and its related application parameters, and provide consideration of motor behavioral research and clinical applications in physical therapy.

• 한국양식학회지
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• 제12권1호
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• pp.71-77
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• 1999

The potential utility of injection media (sucrose, PEG, and liposome) was demonstrated for direct gene transfer into olive flounder (Paralichthys olivaceus) muscles. Based on the use of sucrose (final cone. 20%), PEG 8,000 (final cone. 10%) or liposome (twice us of DNA injected), the present injection strategy significantly improved the level of transgene expression as well as persistent duration of expression. The increased amounts of expression in DNA injection with sucrose, PEG, and liposome were as high as from 2.1 to 4.9-folds of conventional TE-based DNA injection. The best result was obtained from injections of liposome-encapsulated DNA in which the expression was detectable at least 32 days after injection when compared to only 8-16 days from TE-based injections.

• 반도체디스플레이기술학회지
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• 제16권3호
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• pp.106-110
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• 2017

Due to the plasma applied from the outside, which acts as an etchant during the etching process, considerable heat is transferred to the wafer and a separate cooling process is performed to effectively remove the heat after the process. In this case, a direct cooling method using a refrigerant is suitable for cooling through effective heat exchange. The direct cooling method using the refrigerant using the latent heat exchange is superior to the cooling method using the sensible heat exchange. Therefore, in this paper, AMESim is used to design a direct refrigerant cooling system using latent heat exchange simulator was built.The constructed simulator is reliable compared with the actual experimental results. It is expected that this simulator will help to design and search for optimal process conditions.

• KIEAE Journal
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• 제8권1호
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• pp.45-52
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• 2008

Daylighting systems can improve the luminous quality of indoor environment and reduce the building's electric lighting energy consumption. For designing good daylighting, place the light where it is desired and avoid excessive contrasts, glare and high light levels. Sun scoop, light scoop and sun catcher systems have been used for alternative systems compared to other natural lighting systems. This study aims to evaluate daylighting performance of sun scoop, light scoop and sun catcher systems using scale model experiments. For the purpose, the 1/10 scale models of the systems were made as the same areas of glazing(10 percent of floor area) on the top of the center roof. Totally 15 measuring points of illuminance on the horizontal work plane were monitored from 09:30 to 12:30 on October 29, 2007. Agilent data logger and photometric sensors Li-cor were used. As the results, the topside lighting systems can improve the illumination uniformity than side lighting and top lighting. However, the appropriated shading system should be integrated to prevent the direct sunlight.

• 대한임상전기생리학회지
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• 제9권2호
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• pp.19-24
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• 2011

Purpose : This study is to examine the effects of transcranial direct current stimulation on the excitability of the central neuron. Methods : This study selected 24 suitable women in their twenties. A positive electrode of transcranial direct current stimulation was placed on the primary motor area (M1) C4 and a negative electrode was placed on the left supraobital. A stimulation of 0.04mA/$cm^2$ was applied for 20 minutes. H-reflex and V wave used diagnostic electromyography. An active electrode was placed at the muscle belly of the medial gastrocnemius muscle at a prone posture. An electrical stimulation was given to the posterior tibial nerve. Measurements were made before and after the stimulation. All data were analyzed with SPSS 12.0 and between each measuring before and after the change of the H-reflex and V wave amplitude. Results : There were no significant differences in all H wave, M wave, and V wave amplitude before and after transcranial direct current stimulation. There were no significant differences in the change of H/M ratio and V/M ratio before and after transcranial direct current stimulation. Conclusion : We know that transcranial direct current stimulation cannot have an influence on a normal grown-up person's central neuron.

• 한국항공우주학회지
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• 제40권2호
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• pp.178-183
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• 2012

위성체의 열진공 시험에는 우주 열환경을 모사하기 위하여 직접 방열판 표면에 열을 공급하는 접촉식 히터와 일정 거리를 두고 간접적으로 복사에 의해 열을 공급하는 비접촉식 히터가 사용된다. 이는 태양 복사 뿐 아니라 지구의 적외선 및 알베도(Albedo)를 모사하며, 열환경 시험 요구에 따라 정의된 온도 조건에 필요한 열을 공급하기도 한다. 일반적으로 접촉식 히터 사용이 불가할 경우 비접촉식 히터를 사용하게 되는데, 이때 복사에 의한 열전달량을 고려하여 적절한 히터파워를 산정하고 히터 미작동시 방열판과 챔버 슈라우드와 열교환에 있어 간섭이 없도록 히터의 위치를 설정하는 것이 필요하다. 본 논문은 열해석상용 프로그램인 SINDA를 이용하여 비접촉식 히터의 최적화 열설계를 수행하였으며, 이를 통해 시험시 유효한 설계값을 도출하였다.

• Journal of Acupuncture Research
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• 제21권6호
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• pp.221-231
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• 2004

Objective : The purpose of this report is to examine the effects of direct moxibustion in the Low back pain patient. Methods : Clinical studies were done 30 patients who were treated with low back pain to Dept. of Acupuncture & Moxibustion, of Oriental Medical Sang-Ji University from September 1, 2003 to August 31, 2004. We treated them by Oriental medical therapy(including direct moxibustion)for 10 days. The evaluation was performed five times(admission day, before and after each twice). Results : 1. VAS was decreased after direct moxibustion for 10 days significantly(p<0.01). 2. After direct moxibustion, S.L.R. T angle of patients were increased. ConclUsions : We brought to the conclusion that direct moxibustion has possibility to the efficient to cure the Low back pain. So we suggest the possibility to use this treatment for Low back pain.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.328-330
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• 1994

The Ultrasonic motor(USM) has many good characteristics such as high torque at low speed range, large holding torque based upon frictional force, high speed response, flexible free ferns, compactness in size, low magnetic noise and silentness in motion. Because of having low speed rotation, USM is good as an actuator of a small size direct drive (DD) manipulator. The acturators for the DD manipulators must have good controllability on the speed and torque from zero to maximum value continuously. New method was developed for speed and torque control by the phase difference control of the two-phase driving signals of the motor. Then rule adjustable compliant and dumped motion was realized on the output shaft of the motor by PD control of the output shaft angle.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.418-421
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• 2000

A new direct colorimetric assay of microcystin in water and algal samples is proposed consisting of two procedures as follows: 1) the elimination of phosphorus in the sample and concentration of microcystin using a C(sub)18 cartridge, 2) the detection of the released phosphorus by the ascorbic acid method and determination of protein phosphatase (PP) inhibition by microcystin. The optimum amounts of phosphorylase ${\alpha}$ and PP-1 in 50 ${\mu}$L concentrated sample were 50$\mu\textrm{g}$/50${\mu}$L buffer and 1.0unit/50${\mu}$L buffer, respectively, for the best assay. The pH for the maximum activity of PP-1 was 8. The minimum detectable concentration for this method was about 0.02$\mu\textrm{g}$/L, which is sufficient to meet the proposed guideline level of 1$\mu\textrm{g}$ microcystin/L in drinking water. Consequently, it would seem that the proposed direct colorimetric assay using PP is a rapid, easy, and convenient method for the detection of microcystin in water and algal samples.