• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.151-155
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• 1993

Evoked potentials(EP) measured with scalp electrodes are often described as a deterministic process corrupted by uncorrelated electrical activities occuring in the brain and These electrical activities(ongoing EEG) refer to noise in EP recording. The Conventional method to determine the EP waveform requires long recording time. Unfortunately most of algorithm developed are too complicated for implementation in real time. Thus, conner EP recording devices use Ensemble average for real time processing. In this paper introduce EP recording hardware for processing advanced algorithm in real tlne. This hardware is composed of DSP chip(TMS320c25) and microcomputer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.80-92
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• 1977

This experiment investigated the effect of various moisture levels on the top and root growth of barley and its yield. Resistant varieties to excess moisture injury shortened plant height, but tillered more, having creeping plant type compared with ordinary one, and greater portion of root of this varieties occured at the deeper soil depths with longer root length. However, susceptible one to excess moisture injury showed an inversed trend when compared with the untreated one. Oversaturated treatment compared with the untreated increased a little bit soil temperature and Eh of soil. Increased root activity and increased yield were obtained with resistant varieties compared with the untreated. Lower root activity and less yield than those of the untreated were observed in both extreme treatments. Yield reduction in both the extreme treatments was mainly due to reduction of tiller number, grain number and 1, 000-grain weight. Highest yield reduction was marked at the stage of internode elongation in the oversaturated and at the booting stage in the overdried treatment.

• The Journal of the Korea Contents Association
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• v.12 no.1
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• pp.318-328
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• 2012

The purpose of present study was to determine effects of a PNF combination pattern training on muscle activity of lower extremities and gait ability in hemiparetic subjects. Twenty chronic stroke patients participated. Participants were randomly divided into either control group and experimental group. Experimental group received PNF combination pattern training, four times per a week for six weeks and control group received general exercise training. For the lower limbs muscle activity, RMS of action potential were analyzed and gait ability tests was conducted with 10MWT, DGI and F8WT. For the significance test of control and experimental group for measuring time by exercise application method, two-way repeated measure ANOVA. As the result, muscle activity of RF(p<.05), VM, TA, LH, LG was significantly increased between measurement period(p<.001), In VM, TA, LH, LG, there were interactions each measurement time and between group. 10MWT, DGI, F8WT in gait ability was significantly improved between measurement periods(p<.001) and In 10MWT, DGI, F8W, there were interaction each measurement time and between group. In conclusion, the PNF combination pattern application will be effective strategy to increasing the muscle activity and improving gait ability in the rehabilitation of stroke patients.

• Korean Journal of Materials Research
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• v.11 no.8
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• pp.679-684
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• 2001

The surface of natural graphite has not only good electrical conductivities and lubrication properties but also has strong hydrophobicity. There are no functional groups and chemical properties on it. It is difficult to join with any other ions and to disperse in aqueous system. In order to increase dispersion ability throughout modification of surface property, it is necessary to let graphite have some function on its surface by the adsorption of surfactant molecules. In this study, using zeta potential adsorbed surfactant molecules(ABDM) on graphite surface and its surface Properties turn hydrophobic into hydrophilic. The dispersing mechanism of graphite particles in aqueous system has been explained using the DLVO theory, It is concluded that the high dispersable graphite suspension of which dispersing stability$(T_{1/2})$ is 44.5 hours at pH 10 and 22.5mV zeta potential can be produced.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.820-824
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• 2008

Electret filter media are used in general ventilation filters, disposable respirators, vehicle cabin filters, vacuum cleaners and room air cleaners. There are basic mechanisms of interception, inertial impaction, diffusion, gravitational settling, electrostatic attraction by which an aerosol particle can be deposited onto a fiber in a filter. The ability of fine particle removal strongly depends on the electrostatic forces between particles and polarized fibers. Thus, the stability of the fiber polarization is a major factor in the reliability of electret filters. In this study, the electret filter is made by electrospinning process using Polystyrene which is dissolved by 5 : 5 of Tetrahydrofuran (THF) and Dimethylformamide (DMF). Also the electrical properties and the filtration performances of electrospun filter media are Quantitatively investigated. Electrical properties of electrospun filters have been studied on surface charge potential and surface charge density. Also the filtration performance of the electret filters are evaluated on collection efficiency. The surface charge potential and the surface charge density of electrospun PS filters are increased with increasing applied voltage and saturated at 30 kV of applied voltage. Also collection efficiency of electro spun filters is increased with increasing surface charge potential and surface charge density. But the surface charge potential is decreased by natural decay and it causes deterioration of particle collection efficiency.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1998.05a
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• pp.4-4
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• 1998

서울 및 서울 인근 주민들의 식수 공급을 위하여 1978년에 건설된 매설 상수배관은 전기방식 조처없이 콜탈에나벨만으로 피복된채 지하철 및 각종 전기설비가 복잡하게 산재된 서울지역에서 근 20년 유지되고 있다. 따라서 이 배관에 대한 부식 상태를 파악하는 것이 배관의 안전성 확보 및 대책수립, 배관수명의 연장, 중단없는 상수공급 동의 차원에서 매우 중요하다. 이 조사의 목적은 건설후 20년이 경과하여 노후된 매설 상수배관에 대한 기본적인 부식환경 및 피복 상태를 조사하여, 부식상태를 진단하고 향후 대책을 세우기 위한 기초 자료를 확보하는 것이다. 조사의 대상은 1978년에 건설된 서울지역 매설 상수배관 103 Km이었으며, 주요 조사 내용은 토양의 pH, 토양비저항과 같은 기초적인 부식환경조사, 전 배관에 대한 부식전위측정, 부식환경 조사로부터 판정된 부식 우려구간을 대상으로 피복손상부 탐측 및 시험굴착, 그리고 상기 조사의 결과를 검토하는 것이다. 조사 결과, 기본적인 부식환경 변수로 예상되던 토양의 전기비저항, 습도, pH는 부 식전위 및 토양종류와 상관관계를 보이지 않았으며, 상수배관 주변의 토양비저항은 대부분 8,000 ~ 10,000 ${\Omega}{\cdot}cm$, 토양 pH는 대부분 5와 6사이에 집중되었다. 전체적으로 볼 때 매설 상수배관은 예상보다 양호한 배관 상태를 유지하고 있다고 판단되나, 일부 간섭구간은 방식보완이 필요한 것으로 조사되었다. 즉 일부 간섭에 의한 미방식 지역은 배류기나 희생양극 설치와 같은 조속한 방식보완 조치가 필요하며, 과방식이 우려되는 곳은 강제배류기의 출력을 크게 낮추는 것이 필요하다. 이때 부식전위가 크게 올라가는 지점이 있으면 부근 가까운 지하철 레일과 선택배류기로 연결하는 것이 바람직하다.

• Nuclear Engineering and Technology
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• v.8 no.1
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• pp.19-27
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• 1976

The strain ageing behaviour of Zircaloy-4 has been studied in the temperature range 175$^{\circ}C$ to 575$^{\circ}C$ for both quenched and annealed specimens. The strain ageing in quenched Zircaloy-4 was found in the temperature range 175$^{\circ}C$ to 50$0^{\circ}C$ and its Peak occured at 3$25^{\circ}C$ while the strain ageing in annealed specimens occured in the temperature range 175-575$^{\circ}C$, showing two peaks, one at 323$^{\circ}C$ and a higher one at 45$0^{\circ}C$. The peak at 3$25^{\circ}C$ in both quenched and annealed specimens is considered to be due to the segregation of interstitial oxygen atoms to cell walls during ageing. The peak at 45$0^{\circ}C$ in annealed specimens is considered to he due to the interaction of dislocations with Fe atoms. It has been found that strain ageing stress at ~30$0^{\circ}C$ in zirconium alloys is proportional to the square root of oxygen content.

• Radiation Oncology Journal
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• v.16 no.1
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• pp.63-69
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• 1998

Purpose : This study is to evaluate the efficacy of small bowel displacement system(SBDS) in post-operative pelvic radiation therapy(RT) of rectal cancer patients by measurement of small bowel volume included in the radiation fields receiving therapeutic dose. Materials and Method : Ten consecutive new rectal cancer patients referred to the department of Radiation Oncology of Samsung Medical Center in May of 1997 were included in this study. All patients were asked to drink $Castrographin^(R)$ before simulation and were laid prone for conventional simulation and CT scans with and without SBDS. The volume of opacified small bowel on CT scans, which was to be included in the radiation fields receiving therapeutic dose, was measured using Picture archiving and communication system (PACS). Results : The average small bowel volumes with and without SBDS were 176.0ml(5.2-415.6ml) and 185.1ml(54.5-434.2ml), respectively The changes of small bowel volume with SBDS compared to those without SBDS were more than $10\%$ decrease in three, less than 10% decrease in two, less than $10\%$ increase in three, and more than $10\%$ increase in two patients. Conclusion : No significant advantage of using SBDS in post-operative pelvic RT for rectal cancer patients has been shown by small bowel volume measurement using CT scan considering additional effort and time needed for simulation and treatment setup.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.136-141
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• 2002

Purpose : The role of biceps pulley is stabilizing sling for the long head of the biceps tendon against anterior shearing stress in the rotator interval. The purpose of this study was to classify arthroscopic findings of biceps pulley and to evaluate the relationship with shoulder pathology. Materials and Methods : From January 2002 through July 2002, we observed biceps pulley in 49 cases of shoulder pathology treated with arthroscopically. There were 22 cases of anterior instability, 12 cases of rotator cuff tear, 5 of impingement syndrome, 6 of frozen shoulder, 2 of superior labral injury and 1 of each scapulothoracic bursitis and biceps dislocation. We classified biceps pulley as four types according to the arthroscopic appearance. Type I its stretched type. type II as sling type, type III at detached sling type, and type IV as concealed type. Results : We observed stretched type in 24 cases $(49\%)$, sling type in 5 cases $(10\%)$, detached sling type in 2 cases, concealed type in 1 case, and unidentified cases in 17 cases $(35\%)$. Conclusion : Development and variation of biceps pulley may have symptomatic correlation according to the degree of shoulder motion or pathologic status.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5867-5874
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• 2012

The aim of this study was to find on muscle architectural and tissue compliance of biceps brachii in stroke patient based on elbow joint angle. The subjects of this study were twelve hemiplegic adults after stroke with passive range of motion in the elbow from $10^{\circ}$ to $90^{\circ}$ and Modified Ashworth Scale score 1 to 3 were recruited. Ultrasonography and Myotonometer was used to measure biceps brachii muscle pennation angle, fascicle length, and tissue compliance at the rest condition and pennation angle, fascicle length, and tissue compliance of the biceps brachii muscle were measured in the affected and unaffected sides of people after stroke at 9 different elbow angles ranging from $10^{\circ}$ to $90^{\circ}$ at the rest condition. The results of this study, comparisons found that the pennation angles of the affected biceps brachii muscle were significantly larger(p<.05) than the unaffected muscle in the most extended positions($<40^{\circ}$), whereas the affected fascicle lengths were significantly shorter(p<.05) than the unaffected muscle in most flexed positions($>20^{\circ}$), and the affected tissue compliance were significantly lower(p<.05) than the unaffected muscle in most extended positions($<50^{\circ}$) Therefore, pennation angles, fascicle lengths, and tissue compliance were found to be joint-angle-dependent in both the affected and unaffected sides at the rest condition. Suggest that, the results data can be used as a muscle architectural changes and clinical treatment research in stroke patients.