• 한국운동역학회지
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• 제15권1호
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• pp.207-219
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• 2005

The purpose of this study was to determine the effect of the foot rotation on the lower limb muscles. Fourteen subjects performed step-up/step-down at a cadence of 80 beats/min, exercises with the foot neutral, $35^{\circ}$ internally rotated, and $35^{\circ}$ externally rotated, respectively. For each variable, a one-way analysis of variance (ANOVA) was used to determine whether there were significant differences between genders and among the eight types of jump. When a significant difference was found in jump type, post hoc analyses were performed using the Tukey procedure. A confidence level of p < .05 was used to determine statistical significance. The results showed that significant changes in averaged IEMG values occurred with the internal rotation of the foot in the lateral gastrocnemius during the knee extension, and in the semitendinosus during the knee flexion. During the knee extension, however, the internal rotation of the foot produced a significantly lower Averaged IEMG values than the neutral foot position in the medial gastrocnemius. The results also found that the peak IEMG activity of the rectus femoris during the knee extension for the external rotation of the foot was Significantly higher than the corresponding values in the neutral position of the foot, while the intenal rotaion of the foot exhibited a significant difference with the neutral position of the foot in the semitendinosus during the knee flexion. In general, the foot rotation position did not influence the average IEMG and Peak IEMG values of most muscles. The practice of adopting foot rotation to selectively strengthen individual muscles of the lower limb was not supported by this study. The external rotation of the foot produced high muscle activities in the quadriceps during the knee extension. For the knee extension, therefore, maintaining a laterally rotated position should be need for stable and comfortable position.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1186-1195
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• 1993

The Japanese type combine harvester has adopted rubber crawlers for the driving mechanism from first production . However, combine harvesters with movable track rollers in the rubber crawler system have been adopted recently for the purpose of stability at the time of climbing over the footpaths between rice fields, as the results of the machines becoming large. However, the dynamic characteristics of movable track rollers have not been clarified. For this reason, the design of movable track rollers depends on trial and errors. It is known that vibration characteristics of the vehicle with movable track rollers are different from the vibration characteristics of the vehicles with fixed track rollers even though the track roller arrangements are the same. Therefore, the theoretical analyses of movable track rollers must be hurried in order to formulate a reasonable track roller arrangement design. the authors have studied the vibration characteristics of the rubber crawler ve icle with fixed track rollers. in this study, the dynamic model of the vehicle with movable track roller sis compared with the dynamic model of the vehicle with fixed track rollers. Next, motions are simulated to analyze the movable track rollers by expanding the motion equation which were constructed for the dynamic model of the fixed track rollers.

• 한국의류산업학회지
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• 제13권5호
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• pp.806-814
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• 2011

A solar jacket, which utilizes solar energy for generating electricity, is an example of clothing developed by the fusion of multiple technologies; such fusion of technologies can lead to further developments in the clothing industry and other industries in general. Many research institutes and garment manufacturing companies in Europe and America are developing solar garments; various solar-based products manufactured using solar cells, photovoltaic batteries, etc. are being sold at high prices. The purpose of this study was to investigate the development status of solar garments and their application for generating photovoltaic energy; the study also identified the type of design and upper body clothing preferred by Korean in their early 20s. The survey participants were 188 university students aged between 20 and 25. The design of the proposed six types of solar clothing was evaluated and rated; they were then ranked on the basis of the ratings. A survey on the management of solar garments was conducted, and ratings were assigned according to a 5-point Likert scale, with 5 indicating the strong affirmation. The survey results showed that among the six types of clothing, protective clothing (50%) and sportswear (22%) were more preferable than the others (working clothes (16%), casual clothes (3%), everyday wear(6%), and suits(1%)). Among the six proposed designs, the jumper design (22%) and jean jacket design (21%) were preferred over the others (casual jacket (19%), casual jacket I (15%), classic suit (14%), and climbing jacket (9%)). Factorial analysis of the management of solar garments revealed that the most important factors were the properties of the solar cell and time required for battery charging, and the second important factors were clothing weight and comfort.

• 대한족부족관절학회지
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• 제1권2호
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• pp.89-94
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• 1997

The functional disabilities post arthrodesis of the ankle include difficulty in climbing inclined surface, such as hill, ramps, or stair even through without pain. There will be periankle joints arthrosis as time passes. Total ankle replacement permits remobilization, no need for prolonged immobilization. There will be no increas in the mechanical stress of the neiboring joint. Total ankle replacement has been proposed as an alternative to arthrodesis in the management of painful arthrosis of the tibiotalar joint recently. We performed 7 cases of replacement from 1990. 4. 1 to 1996. 7. 1 with 2-3 years follow up. A retrospective review was undertaken for 7 patients with the arthrosis of tibiotatar joint. The results were as following. 1. The clinical results according to the point system for ankle study evaluation were excellent in 2 cases, good in 4 cases, and fair 1 case. 2. The improvement was especially obvious in terms of pain and functional recovery. 3. Total ankle replacement especially unconstrained type seems quite good alternative to arthrodesis.

• PNF and Movement
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• 제12권2호
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• pp.89-96
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• 2014

Purpose: The purpose of this study was to examine the influence of foot angles on plantar pressure and the center of pressure (COP) trajectory length during level walking. Methods: The study subjects were 30 female university students without orthopedic diseases in the foot. The foot angle was divided into three forms (out-toeing, normal, in-toeing). The subjects practiced each type of gait, and then performed each of level walking, three times, and their averages were calculated. A plantar pressure measurement instrument was used, and the maximum force was obtained by dividing the foot into nine regions covering the anterior medial-lateral, middle medial-lateral, and posterior medial-lateral. The COP trajectory length was statistically processed by obtaining medial-lateral, anterior-posterior, and entire travel distance. Results: During normal walking, the maximum force was significantly higher in the anterior lateral than in the other areas, and the COP trajectory length was significantly shorter in the front-back and entire travel distances (p<0.05). During stair climbing. Conclusion: Walking at abnormal foot angles does not cause appreciable problems in the short term as pressure is concentrated on a specific plantar part. However, it becomes the cause of deformed foot structures and can result in musculoskeletal disabilities in the long term. Therefore, a kinesiatrics-based intervention is required to maintain normal foot angles.

• 생물환경조절학회지
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• 제23권2호
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• pp.123-130
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• 2014

참외 재배환경은 토양 위의 수평바닥에서 재배된 것을 수확하여야 하며, 참외가 잎으로 덮여져 있어 인식이 어렵고, 덩굴성 줄기로 인해 참외를 그립하기에도 매우 불리하다. 이러한 재배환경에 적합하도록 엔드이펙트, 머니퓰레이터, 인식장치 등의 참외 수확 로봇을 개발하였고 이를 시험하였다. 엔드이펙터는 수확물을 잡기 위한 그립퍼와 줄기를 절단하는 커터로 구분되며, 그립퍼는 4개의 핑거가 동시에 구동하고, 커터는 2개로 전후진 동작이 되도록 설계하여 파지력과 절단력을 제어할 수 있도록 하였다. 머니퓰레이터는 중심축을 기준으로 회전을 하는 L-R형 모델에 직교 좌표형과 셔틀형 머니퓰레이터를 조합한 4축 매니플레이트 구조로 설계하였다. 인식장치는 1차 인식장치인 GVC와 2차 인식장치인 LVC를 이용하여 참외를 식별하고 그 중에서 당도나 숙도를 예측하여 선별하였다. 이 장치를 이용하여 로봇의 성능시험을 한 결과 수확시간은 평균 18.2sec/ea, 픽업율은 평균 91.4%, 손상율은 평균 8.2%, 선별율은 평균 72.6%로 나타났다.

• 한국응용과학기술학회지
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• 제36권3호
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• pp.804-812
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• 2019

The purpose of this study was to investigate the effects of different types of exercise training on neurodegeneration and cognitive function in mice with impaired glucose tolerance (IGT). Thirty-six male C57BL/6 mice were randomly assigned to the control (CO, n = 9) and impaired glucose tolerance (IGT, n = 27) groups. The IGT group consumed 45% high fat diet for 4 weeks and received 40 mg/kg of streptozotocin twice in the lower abdomen to induce IGT. After the IGT induction period, the IGT group was subdivided into IGT + sedentary (IGT, n = 9), IGT + endurance exercise (IGTE, n = 9), and IGT + resistance exercise (IGTR, n = 9). The IGTE and IGTR groups performed treadmill and ladder climbing exercises 5 times per week for 8 weeks, respectively. Fasting glucose and glycated hemoglobin (HbA1c) levels were significantly higher in IGT group than in CO, IGTE, and IGTR groups (p < 0.05). HOMA-IR was significantly higher in IGT group than CO group (p < 0.05). Hippocampal catalase (CAT) was significantly lower in IGT group than in CO group (p < 0.05), while beta-amyloid ($A{\beta}$) was significantly higher in IGT group than in CO group (p < 0.05). Hippocampal tau was significantly higher in IGT group than in CO, IGTE, and IGTR groups (p < 0.05). The Y-maze test performance for cognitive function was significantly lower in IGT group than in CO, IGTE, and IGTR groups (p <0.05). These results suggest that IGT induces neurodegeneration and negatively affects cognitive function, while regular exercise may be effective in alleviating neurodegeneration and cognitive decline regardless of exercise type.

• 한국응용과학기술학회지
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• 제38권3호
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• pp.750-761
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• 2021

이 연구는 노화된 흰쥐를 대상으로 규칙적인 저항성 운동에 유산소 운동을 병행하는 훈련을 실시하여 골격근에서 나타나는 혈관신생 관련 단백질 발현의 반응을 관찰하기 위해 수행되었다. 연구의 목적을 위해 자연적으로 노화된 SD계열 흰쥐(20-24개월령, N=18)를 사용하여 통제(CON, n=6), 저항성 운동(RE, n=6), 저항성+유산소 운동(RE+AE, n=6) 집단으로 구분하였다. 저항성 운동 집단은 실험동물용 사다리를 이용하여 매회 3세트×4회의 운동을 실시하였고 저항성 운동+유산소 운동 집단은 매회 2세트×3회의 사다리 오르기와 추가적인 30분간의 트레드밀 달리기를 수행하였다. 총 8주간의 운동 훈련 종료 후 가자미 근과 장지신근을 적출하여 분석에 사용하였다. 골격근에서 혈관신생 관련 단백질들(HIF-1α, VEGF, FLK-1, Ang-1, Ang-2)의 발현 수준을 분석하기 위해 western blot을 실시하였다. 연구결과, 저항성+유산소 운동 집단에서 가자미근(type I 근육)의 HIF-1α, VEGF, FLK-1, Ang-1, Ang-2 단백질 발현이 통제집단에 비해 높았으며 저항성 운동만 수행할 경우 HIF-1α, VEGF, Ang-1, Ang-2 단백질 발현이 통제집단에 비해 높았다. 또한 가자미근에서 저항성+유산소 운동훈련 집단의 Ang-2 to Ang-1 ratio가 저항성 운동 집단에 비해 높아 운동훈련 유형별 차이를 보였다. 한편, 장지신근(type II 근육)에서 HIF-1α는 저항성 운동 훈련에 의해서만 증가된 반면 VEGF와 FLK-1 단백질 발현은 두 훈련 유형 모두에서 증가되었고 운동 훈련 유형별 차이는 관찰되지 않았다. 또한 장지신근의 angiopoieitin 단백질들의 발현은 운동 훈련에 의한 차이가 없었다. 그러므로 노화에서 규칙적인 운동 훈련은 운동 유형에 관계없이 골격근 혈관신생 반응을 유도하며, 특히 저항성 운동에 유산소 운동의 병행은 type I 근조직 유형에서 혈관신생에 대한 추가적인 긍정적 효과를 가질 수 있다.

• 한국안전학회지
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• 제35권5호
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• pp.49-58
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• 2020

In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

• 한국조경학회지
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• 제51권2호
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• pp.54-67
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• 2023

태산(泰山)은 해발 1,532m로 중국에서 제일 높은 산이 아님에도 불구하고 "오악독존(五嶽獨尊)"과 같은 높은 명성을 가지고 있다. 가이드북은 특정 이벤트나 시설 등에 대한 안내와 설명을 담은 책이나 소개서이다. 특히 관광지에 대해 상세하면서 정확한 정보를 다른 상업홍보 보다 시각적이면서도 다량으로 제공한다는 특성이 있다. 이에 태산에 관한 경관을 묘사한 가이드북을 연구 재료로 활용하여 경관유형 및 요소 분석과 경관요소의 커널 밀도(Kernel Density), 평균중심(Mean Center), 표준차 타원(Standard Deviational Ellipse) 분석을 통해 태산경관 특성을 파악하였다. 본 연구 결과를 요약하면, 첫째, 태산의 경관유형 특성은 자연경관이 가장 많이 나타났으며, 이는 시문과 빅 데이터 분석에 나타난 인간활동 위주의 태산경관 특성과 다르다. 둘째, 세부적인 경관유형별로 보면 경관요소의 비중에 따라 많이 나타난 것은 지형, 구조물, 건물, 식물, 의미, 사람, 이미지 순이라고 할 수 있다. 셋째, 시계열별 경관요소로 보면 ''봉선(封禅)"과 ''제사(祭祀)", ''전설"은 1950년대와 1980년대에 많이 나타났으며 1990년대 이후는 ''등반", ''멀리 바라보기"가 많이 나타났다. 넷째, 태산 경관요소의 공간분포는 전시대에 걸쳐 태산 대정 (岱顶)과 대묘 (岱廟)에 많이 분포되어 있다. 이는 향후 태산 풍경명승지의 중요 공간이 될 수 있다. 그리고 전체적으로 경관요소는 태산 풍경명승지 집중분포에서 태산과 태안 도시지역을 포함하는 분산분포의 형태로 나타났다. 이는 향후 태산 풍경명승지의 경관 보정과 가이드북 재제작을 할 때 필요한 시사점을 제시하고자 한다.