• Title/Summary/Keyword: Weight-bearing

검색결과 994건 처리시간 0.026초

조합 유전 알고리듬을 이용한 증기 터빈 회전체-베어링 시스템의 최적설계 (Optimal Design for Steam-turbine Rotor-bearing System Using Combined Genetic Algorithm)

  • 김영찬;최성필;양보석
    • 한국소음진동공학회논문집
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    • 제12권5호
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    • pp.380-388
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    • 2002
  • This paper describes the optimum design for low-pressure steam turbine rotor of 1,000 MW nuclear power plant by using a combined genetic algorithm, which uses both a genetic algorithm and a local concentrate search algorithm (e.g. simplex method). This algorithm is not only faster than the standard genetic algorithm but also supplies a more accurate solution. In addition, this algorithm can find the global and local optimum solutions. The objective is to minimize the resonance response (Q factor) and total weight of the shaft, and to separate the critical speeds as far from the operating speed as possible. These factors play very important roles in designing a rotor-bearing system under the dynamic behavior constraint. In the present work, the shaft diameter, the bearing length, and clearance are used as the design variables. The results show that the proposed algorithm can improve the Q factor and reduce the weight of the shaft and the 1st critical speed.

자세균형제어 시스템의 개발 (Development of Postural Balance Control System)

  • 양길태;김영호;임송학;장윤희;문무성
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.276-279
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    • 1997
  • A simple bio-feedback system was developed to monitor and to analyze patient's postural balance. Two load celIs were used to measure the weight of each side. A specially designed electronic circuit was made to pick up the weight signals and to feed into the data acquisition system. Clinical trials were also made on 20-30 year-old normal subjects and nine hemiplegia patients who had the potential instability in weight bearing. A Microsoft window-based software collected and analyzed the postural balance data. Normal subjects showed only 5% deviations of their body weight. However, hemipegic patients had significant weight shifts toward the healthy limb. With the present system, patients can also exercise their balance and weight bearing. The present system should be of convenience to monitor in real-time and analyze the postural balance control of hemiplegic patients.

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승용차용 Wheel Bearing Hub Unit 설계를 위한 주행 하중조건의 실험적 연구 (Experimental Study of Driving Load Conditions for the Wheel Bearing Hub Unit of Passenger Car)

  • 김기훈;유영면;임종순
    • 한국자동차공학회논문집
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    • 제10권2호
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    • pp.166-173
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    • 2002
  • The wheel bearing hub unit is developed type of wheel bearing unified with the hub parts. It has advantage of reducing the weight and the number of components. And, it also improves uniformity of manufacturing quality, In order to design the wheel bearing hub units, many techniques are used such as load analysis, structure analysis and bearing characteristics analysis and so forth. These techniques need highly accurate load conditions founded on service conditions. In this study, to design the wheel bearing hub units used widespread in passenger cars, the service load was measured through driving tests on the public roads and in the special events. The public roads are classified into highway, intercity road, rural road, urban road, and unpaved road so as to know what the characteristics of the road loads are. The results of the tests showed that the wheel force was relative to the lateral acceleration, and also could be calculated from the lateral acceleration. The lateral acceleration was measured from 0.0G to 0.6G in general driving on the public roads, with different distributions in each road type. In special events, the maximum lateral acceleration was measured from 0.8G to 1.3G.

지오셀을 이용한 투수성 포장의 지지력 평가 (Evaluation of Bearing Capacity for Permeable Pavement using Geocell)

  • 이수형;유인균;이대영
    • 한국지반신소재학회논문집
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    • 제11권3호
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    • pp.11-17
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    • 2012
  • 본 논문에서는 하부층 연약지반 보강공법으로 사용되고 있는 지오셀을 이용한 투수성 도로포장의 지지력 거동 특성을 다루었다. 현장시험을 통해 지오셀 포장의 지지력 변화를 일반쇄석 포장과 비교하여 분석하기위해 FWD를 이용하여 지지력 특성을 평가하였다. 실험결과 1.5mm 두께의 지오셀의 경우 보강효과가 나타나는 것으로 측정되었으며 재하하중이 증가함에 따라 보강효과도 큰 것으로 평가 되었다.

중공 슬래브의 국부지압강도에 대한 시공안전성 평가 (Construction Safety Evaluation of Local Bearing Strength of Hollow Core Slab)

  • 허무원;윤정환;황규석;윤성호;박태원
    • 한국구조물진단유지관리공학회 논문집
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    • 제22권2호
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    • pp.8-15
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    • 2018
  • 중공슬래브는 휨 성능에 영향을 미치지 않는 부분의 콘크리트 단면을 삭제하고 중공재로 치환함으로써 중공재 부피만큼 콘크리트가 줄어들어 자중 감소효과를 가져오는 장점이 있다. 또한, 콘크리트의 물량절감뿐 아니라 친환경적 측면에서 이산화탄소의 배출도 저감할 수 있어 효과적이다. 하지만, 중공재로 치환한 부분의 지압강도가 명확하지 현장 적용 시에 여러 가지 문제점이 발생한다. 이에 본 연구에서는 중공재가 포함된 중공슬래브를 제작하여 각 타입별(트럭 하중 적용 시, 동바리 하중 적용 시 및 잭 서포트 하중 적용 시)로 국부지압강도 실험을 수행하여 중공슬래브 국부 지압강도의 안전성을 평가하고자 한다. 트럭하중 적용 시, 동바리 하중 적용 시 및 잭 서포트 하중 적용 시의 실험결과 중공재 연결부위 및 중공재 상부의 지압강도는 모든 실험체에서 허용 하중 이상을 보유한 것으로 나타났다. 또한 데크 적용 유무에 따른 실험결과도 모두 허용 하중을 초과하여 안정성을 확보하는 것으로 나타났다.

가임여성의 비만도에 따른 체중조절 실태 및 식습관 (A Survey on Weight Control and Eating Behavior in Reproductive Women by BMI)

  • 이은정;김미현;김화영;조미숙
    • 한국식생활문화학회지
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    • 제18권2호
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    • pp.172-180
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    • 2003
  • This study was performed to document the weight loss diet practice and dietary habit related to weight control in child-bearing Korean women. The subjects were 1,434 women aged 17-39 years. The subjects were classified into 3 groups based on BMI: low weight(LW) BMI < 18.5; normal weight(NW), 18.5 BMI 22.9; and overweight(OW), 23.0 BMI. Anthropometric, general characteristics, weight control practice, and the quality of diet were assessed by a questionnaire. LW group had higher rate of smoking and drinking. They also complained more subjective symptom of anemia and used less nutritional supplementation. Weight loss diet had been practiced by about 40% of subjects and the percent was increased with increasing BMI. The reason of weight loss diet were significantly different by BMI groups(p<0.05); LW to keep body in shape, OW for health. Low BMI group had experienced more side effects after weight loss diet(p<0.05). LW group usually used inappropriate method to control weight such as skipping meals and some of OW group reported using drug to lose weight. All subjects have been skipped their meals of 3.9 times per week, especially 4.3 times in LW group. By mini dietary assessment, most of the subjects did not have regular meals. LW group tended to eat what they like and OW group preferred fried food. This study showed that child-bearing aged women make a ceaseless effort apart from their weight, and LW group have a matter of grave concern because of their dietary habit and weight control practice. Additional research should be necessary to assess the relation of health and weight loss diet in young women.

Foot Reconstruction by Reverse Island Medial Plantar Flap Based on the Lateral Plantar Vessel

  • Moon, Min-Cheol;Oh, Suk-Joon;Cha, Jeong-Ho;Kim, Yoo-Jeong;Koh, Sung-Hoon
    • Archives of Plastic Surgery
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    • 제37권2호
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    • pp.137-142
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    • 2010
  • Purpose: Tumor ablation and traumatic intractable ulceration of the plantar surface of the foot results in skin and soft tissue defects of the weight-bearing sole. Simple skin grafting is not sufficient for reconstruction of the weight-bearing areas. Instead, the island medial plantar flap (instep flap) and distally-based island medial plantar flap was used for proper reconstruction of the weight bearing area. However, there are some disadvantages. In particular, an island medial plantar flap has a short pedicle limiting the mobility of the flap and the distally-based island medial plantar flap is based on a very small vessel. We investigated whether good results could be obtained using a reverse island medial plantar flap based on the lateral plantar vessel as a solution to the above limitations. Methods: Three patients with malignant melanoma were cared for in our tertiary hospital. The tumors involved the lateral forefoot, the postero-lateral heel, and the medial forefoot area. We designed and harvested the flap from the medial plantar area, dissected the lateral and medial plantar artery and vena comitans, and clamped and cut the vessel 1 cm proximal to the branch from the posterior tibial artery and vena comitans. The medial plantar nerve fascicles of these flaps anastomosed to the sural nerve, the 5th interdigital nerve, and the 1st interdigital nerve of each lesion. The donor sites were covered with skin grafting. Results: The mean age of the 3 subjects was 64.7 years (range, 57 - 70 years). Histologically, all cases were lentiginous malignant melanomas. The average size of the lesion was $5.3\;cm^2$. The average size of the flap was $33.1\;cm^2$. The flap color and circulation were intact during the early postoperative period. There was no evidence of flap necrosis, hematomas or infection. All patients had a normal gait after the surgery. Sensory return progressively improved. Conclusion: Use of an island medial plantar flap based on the lateral plantar vessel to the variable weight-bearing sole is a simple but useful procedure for the reconstruction of any difficult lesion of the weight-bearing sole.

흰쥐 관절염 모델에서 족삼리와 대릉 배오 전침의 상호억제 효과 (Mutual Inhibitory Effects of Electroacupuncture Applied to Combination of ST36 and PC7 in the Rat Model of Arthritis)

  • 김여정;정연정;이창형;구성태
    • Korean Journal of Acupuncture
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    • 제30권4호
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    • pp.298-304
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    • 2013
  • 목적 : Carrageenan(CA)으로 유발시킨 슬관절염 동물 모델에서 족삼리와 대릉을 배오한 전침의 효과를 알아보기 위해 실험을 수행하였다. 두 개 이상의 경혈에 동시에 자침함으로써 상승작용을 일으키는 연구는 많이 보고되었으나, 본 연구에서는 배합한 경혈(족삼리와 대릉)에 의한 전침 진통 작용의 감쇄 효과가 발생할 수 있는지에 대해 알아보고자 하였다. 방법 : CA을 흰쥐의 슬관절강 내에 주입하여 염증성 통증을 유발시켰다. 실험동물을 임의로 4군으로 배정하였다; PC7 군: 양쪽 상지 대릉 전침 군, ST36 군: 양쪽 하지 족삼리 전침 군, ST36+PC7 군: 양쪽 상지 대릉과 양쪽 하지 족삼리 전침 군, CON: 무처치군. 통증 정도를 측정하기 위해서 weight bearing force의 변화를 측정하였고, 척수의 후각에 유도된 COX-2 발현을 측정하기 위해 면역조직화학법과 western blot 분석을 실시하였다. 결과 : ST36+PC7군은 ST36군과 비교하여, 행동실험에서는 weight bearing force가 유의하게 감소하였고, 면역조직화학법과 western blot 분석에서는 COX-2 발현이 상대적으로 유의하게 증가하였다. 결론 : 이상의 실험결과를 통하여 족삼리와 대릉을 배오한 전침 자극은 슬관절염 모델에서 족삼리 전침의 진통 효과를 감소시킴을 알 수 있었다.

벽식구조 표준시험동에서 중량충격음장에 관한 연구 (Investigation of the heavy-weight floor impact sound field in a testing building with bearing wall structure)

  • 유승엽;이신영;전진용
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.969-973
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    • 2007
  • The heavy-weight floor impact sound field of the receiving room in a testing building with bearing wall structure was investigated using bang machine and impact ball. The sound field was investigated through the impact sound pressure level distribution by the field measurement and computational analysis. Predicted sound field using the computational analysis agree with measurement result in the low frequency band. Result shows that standard deviations of the single number rating value are about 2dB in each impact source. Particularly, impact sound pressure level at 120cm height in 63Hz octave band was 5dB lower than spatial averaging value. It was found that receiving positions in the ministry of construction and transportation notice should be reconsidered.

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탄력 밴드를 결합한 고유수용성신경근촉진법 상지 패턴이 편마비 환자의 신체정렬과 체중지지에 미치는 영향 (The Effects of Elastic Band Combined with Proprioceptive Neuromuscular Facilitation Upper Extremity Patterns on Body Alignment and Weight Support in Patients with Hemiplegia)

  • 최원재;김영균;손경현
    • 대한물리의학회지
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    • 제5권1호
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    • pp.113-123
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    • 2010
  • Purpose : The purpose of this study was to investigate how upper-extremity-movement of PNF(proprioceptive neuromuscular facilitation) with elastic band has effected on arrangement of body and weight-bearing. Methods : The object has worked with 20 patient