• 한국운동역학회지
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• 제16권2호
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• pp.121-134
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• 2006

The purpose of this study was to analyze the effect of different types of rehabilitation training program on the kinetic and kinematic parameters during sit-to-stand movement(STS) in chronic stroke patients. Two groups of hemiparetic patients, experimental and control, participated in the study. The experimental group participated in a 10-week training program (three sessions/wk, $1{\sim}1.5\;hr/session$) consisting of a warm-up, aerobic exercises, lower extremity strengthening. and a cool-down. The control group participated in an aerobic exercise. Three dimensional kinematic analysis and force platform; were used to analyze the duration of STS, lower extremity angle, and weight bearing ability. The experimental group which had more strength of lower extremity displayed decrease in duration of STS. However, the control group showed increases in duration during sit-to-stand movement. The control group flexed their trunk more than the group did Therefore, it took more time to extend their trunk during STS. The duration in sit-to-stand was affected by the strength of lower extremity and the angle of trunk movement. The angles of ankle and knee joint had an influenced on duration of STS. The post experimental group performed with their feet near the front leg of the chair during sit-to-stand, therefore the duration was decreased. The repetitive sit-to-stand movements as a resistance exercise was effective to hemiparetic patients in learning mechanism of sit-to-stand. The control group showed decreased differences in the vertical ground reaction forces between paretic and non-paretic limbs. Their training program included strengthening exercise that may help improving weight bearing ability. The control group showed increases in the center of pressure in the anteroposterior and mediolateral displacement. This means that the stability of movement was low in the control group. Their training program which combined aerobic and strengthening exercises that are more effective to improve the stability of movement.

• 대한물리치료과학회지
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• 제15권3호
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• pp.43-54
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• 2008

Background : We aimed to determine the effect of a mental practice on the electromyography (EMG) activity of the quadriceps femoris muscle of the affected side in a hemiplegic patient during sit-to-stand and stand-to-sit tasks. Methods : We recruited a male patient who had suffered from right hemiplegia. A single-subject experimental A-B-A design was used. The reliability of visual analysis, which was primarily employed in this study design, was supported by using the "2- standard-deviation band" method. The target motions consisted of two activities: sit-to-stand and stand-to-sit. The EMG measurements of the quadriceps femoris muscles of the affected and unaffected sides were made in 8 sessions in the baseline (A), mental-practice (B), and follow-up (A) phases. During the mental practice phase, the 10-min mental practice was performed, and the mental practice was withdrawn in the follow-up phase in order to identify the carry-over effects of the treatment. Data was calculated as the percentage of the ratio of the quadriceps EMG activity values of the affected side on unaffected side. Result : The percentage EMG-activity ratio showed a greater increase in the mental-practice phase than in the baseline, and it was maintained during the follow-up phase. Most of the data points in the mental-practice and follow-up phases were positioned above the "2-standard-deviation band." Conclusion : These findings suggest that mental practice can be used to improve the physical function of hemiplegic patients.

• 대한안전경영과학회지
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• 제14권1호
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• pp.23-31
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• 2012

Recent research on stand-alone focused on the improvement and development of functions for solving problems such as the limited operating time of stand-alone installed at dwelling and their low reliability caused by false alarms, but it is more urgent to study on the operating range of stand-alone sensor in consideration of the impacts of combustion products on residents because the primary goal of fire safety is minimizing casualties. This study purposed to propose the optimized operating range of stand-alone sensor in consideration of the impacts of combustion products on residents. For this purpose, we made a mathematical approach to the change of temperature over the lapse of time in compartment fires similar to house fires, and established the standards of the body's response against heat and smoke based on literature review. In addition, we surveyed domestic and foreign technological standards for stand-alone sensor, and converted them to standards for residents of the body's response against heat and smoke using mathematical model equations and analyzed them comparatively.

• 한국환경과학회지
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• 제32권4호
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• pp.233-242
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• 2023

The objective of this study was to develop a management strategy for the recovery of carbon storage capacity of abandoned coal mine forest rehabilitation area. For the purpose, the biomass and stand carbon storage over time after the forest rehabilitation by tree type for Betula platyphylla, Pinus densiflora, and Alnus hirsuta trees which are major tree species widely planted for the forest rehabilitation in the abandoned coal mine were calculated, and compared them with general forest. The carbon storage in abandoned coal mine forest rehabilitation areas was lower than that in general forests, and based on tree species, Pinus densiflora stored 48.9%, Alnus hirsuta 41.1%, and Betula platyphylla 27.0%. This low carbon storage is thought to be caused by poor growth because soil chemical properties, such as low TOC and total nitrogen content, in the soil of abandoned coal mine forest rehabilitation areas, were adverse to vegetation growth compared to those in general forests. DBH, stand biomass, and stand carbon storage tended to increase after forest rehabilitation over time, whereas stand density decreased. Stand' biomass and carbon storage increased as DBH and stand density increased, but there was a negative correlation between stand density and DBH. Therefore, after forest rehabilitation, growth status should be monitored, an appropriate growth space for trees should be maintained by thinning and pruning, and the soil chemical properties such as fertilization must be managed. It is expected that the carbon storage capacity the forest rehabilitation area could be restored to a level similar to that of general forests.

• 한국산림과학회지
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• 제88권4호
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• pp.541-554
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• 1999

이 연구는 경기도 광주지방에서 잣나무림, 낙엽송림, 참나무류 위주의 활엽수림을 대상으로 임분간 수관통과우, 수간류를 통한 양료유입 양상을 비교하고 수관통과우, 수간류, 토양수별로 양료동태 특성을 알아보고자 하였다. 조사기간동안 총 강우량은 1410.1mm였으며 수관통과우량은 낙엽송림에서 전체강우량의 85%, 잣나무 간벌림에서 84.5%, 잣나무 하예림에서 83.2%, 활엽수림에서 81.2%로 나타나 활엽수림 보다는 침엽수림에서 높게 유입되었다. 수간류량은 활엽수림에서 강우의 2.7%, 잣나무하예림에서 1.3%, 잣나무 간벌림에서 1.2%, 낙엽송림에서 0.8%로 활엽수림이 침엽수림에 비하여 높았다. 강우, 수관통과우, 수간류내 평균 이온농도는 수간류가 가장 높았으며 임분별 평균 이온농도는 양이온, 음이온 모두 낙엽송림, 잣나무림, 활엽수림의 순으로, 활엽수림에 비하여 침엽수림에서 높았다. 수관통과우와 수간류내 양이온 농도는 $NH{_4}^+$-N, $K^+$, $Ca^{2+}$, $Na^+$, $Mg^{2+}$의 순으로 높았으며 음이온 농도는 $SO{_4}^{2-}$, $NO{_3}^-$-N, $Cl^-$의 순이었다. 강우가 수관층을 통과한 후 수관통과우와 수간류에서의 농도변화를 보면 활엽수림의 경우 가장 크게 증가한 이온이 $K^+$인 반면 잣나무림과 낙엽송림에선 $NH{_4}^+$-N이온이 가장 크게 증가하여 수종에 따라 각기 다른 양상을 보였다. 토양수내 양이온 농도는 $Ca^{2+}$, $Mg^{2+}$, $Na^+$의 순으로 높았고, 음이온 농도는 $NO{_3}^-$-N, $Cl^-$, $SO{_4}^{2-}$의 순으로 높았다. 이 중 $NH{_4}^+$-N, $K^+$는 주로 대기로 부터 유입되고 $Ca^{2+}$, $Mg^{2+}$, $Na^+$는 주로 모암의 풍화에 의하여 유입되었다.

• 한국산림과학회지
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• 제82권2호
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• pp.188-194
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• 1993

임령(林齡) 및 환경조건(環境條件)이 유사한 굴참나무천연림(天然林)과 현사시나무인공림(人工林)의 물질생산(物質生産)을 조사(調査) 비교(比較)하기 위하여 전라남도(全羅南道) 모후산지역(母后山地域) 순천대학교(順天大學校) 연습림(演習林)에 위치하고 있는 평균(平均) 20년생(年生) 굴참나무천연림(天然林)과 17년생(年生) 현사시나무인공림(人工林)을 대상으로 각각 $20m{\times}30m$ 조사구를 설치하고 10주씩의 표본목을 선정한 후 뿌리를 제외한 지상부(地上部)의 현존량(現存量), 순생산량(純生産量) 등을 조사하였다. 수종별(樹種別), 부위별(部位別) 현존량(現存量) 추정식(推定式)을 유도 검정한 결과 흉고직경(胸高直徑)(D)과 수고(樹高)(H)를 독립변수(獨立變數)로 하는 상대성장식(相對成長式)(logWt=A+BlogD+ClogH)이 흉고직경(胸高直徑)만을 독립변수(獨立變數)로 하는 상대성장식(相對成長式)(logWt=A+BlogD)에 비하여 적합도(適合度)가 다소 높은 경향을 보였으나 큰 차이는 없는 것으로 나타났다. 임분(林分) 전체(全體)의 지상부(地上部) 현존량(現存量)은 현사시나무림이 55,581kg/ha로서 굴참나무림의 31,275kg/ha보다 1.8배 정도 많았다. 부위별(部位別) 현존량(現存量) 구성비(構成比)는 굴참나무림과 현사시나무림 모두 줄기의 목질부(木質部), 가지, 수피(樹皮), 잎의 순(順)으로 높았으나, 굴참나무림의 경우 현사시나무림에 비하여 수피(樹皮), 가지, 잎의 구성비(構成比)는 높은 반면 줄기의 목질부(木質部) 구성비(構成比)는 낮았다. 임분(林分) 전체의 지상부(地上部) 순생산량(純生産量)은 굴참나무림이 4,267kg/ha/yr.이었으며 현사시나무림은 3,903kg/ha/yr.이었다. 부위별(部位別) 순생산량(純生産量) 구성비(構成比)는 굴참나무림의 경우 잎, 줄기의 목질부(木質部), 가지, 수피(樹皮)의 순으로 높았으며 현사시나무림은 줄기의 목질부(木質部), 잎, 가지, 수피(樹皮)의 순이었다. 순동화율(純同化率)은 현사시나무림이 3.376으로서 굴참나무림의 2.121보다 1.6배 정도 높았으며, 잎의 줄기 생산능률(生産能率)의 경우 현사시나무림이 굴참나무림에 비하여 2.4배 정도 높았다. 현사시나무림은 굴참나무림에 비하여 순동화율(純同化率)이 높은 반면 잎의 현존량(現存量)이 적기 때문에 지상부(地上部) 전체 순생산량(純生産量)은 적었으나, 지속적 축적기관(蓄積器官)인 줄기의 목질부 순생산량(純生産量)이 많기 때문에 임분(林分) 현존량(現存量)이 많은 것으로 나타났다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.325-328
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• 2007

본 연구에서는 소형가스터빈의 고공 및 속도시험, 환경시험 등을 수행하기 위해, 러시아의 SCIAM 연구소에 설치된 기존 대형 시험설비를 개량하여, C-9N 시험스탠드를 개발하는 과정에서 수행된 개념적 설계의 내용을 다루고 있다. 본 시험 스탠드는 환경모사 시스템, 항온유지 시스템, 냉각/건조 시스템, 추력측정 시스템, SAR 시스템으로 구성되어 있다.

• Journal of Welding and Joining
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• 제26권6호
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• pp.48-53
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• 2008

Although Magnetic Pulse Welding(MPW) is not a recently developed technique, it has gained the attention of the automotive industry. MPW has become an accepted welding process because it enables the joining of similar, and dissimilar materials, with a very short cycle time, without the need for filler metal and gases. In this study, the effect of the stand-off distance on the weld strength has been investigated. The compressive strength of the MPW joints was evaluated using UTM. The interface of weld, IMC composition and morpology were studied by SEM and EDS. It was concluded that the stand-off distance and the voltage are the main parameters influencing the strength of weld. In case of too high stand-off distance, it influenced harmful effect because of the resistance of deformation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1640-1642
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• 2000

We were fabricated of NiCr thin film resitors(TFR) on $Al_{2}O_3$ substrates by dc magnetic sputtering, system. The characteristics of electrical resistance by substrates & annealing condition on the resistors were studied by X-ray Diff. and SEM, ESCA.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2766-2768
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• 2000

We were made the automatic measurement system of sheet resistance and resistivity of semiconductor and metals with accuacy. The use of this system measured SRM(Standard Reference Materials) silicon wafers which calibrated by NIST. From this result. this system operated with the standard deviation within maximum ${\pm}$1% error.