• 제목/요약/키워드: Loss analysis

검색결과 8,452건 처리시간 0.046초

뇌졸중환자의 보행 관찰분석 (Observation of Gait Analysis of the Stroke Patient)

  • 배성수;김식현;김상수
    • PNF and Movement
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    • 제6권1호
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    • pp.21-25
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    • 2008
  • Purpose : The purpose of this study was conducted to find out observation at gait analysis of the stroke patient with proprioceptive neuromuscular facilitation(PNF) concept. Methods : This is a literature study with books, seminar note and international PNF course book. Results : Stroke patient gait was poor initial contact by weakness of tibialis anterior or weakness of contralateral plantar flexor, poor loading response by loss of deep sensation, poor mid stance by loss of deep sensation, weakness of tibialis anterior and weakness of plantar flexors eccentric control, poor terminal stance, pre-swing, initial swing by loss of deep sensation and stiffness fo deep toe flexors. Conclusion : Stroke patient gait determine on loss of mobility, pain, fear, trunk muscle weakness, loss of coordination, loss of deep sensation, neglect and apraxia. Therefore observational gait analysis of the stroke patient focus on gait cycle and take out hypotheses from the gait cycle. These hypotheses have to define accept or not by parameters. Treatment plan made with the hypotheses.

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구조물의 회복탄력성 기반 성능평가법에 대한 고찰 및 적용 방안에 관한 연구 (A Study on the Resilience-Based Performance Evaluation Method of Structures and Their Application Plan)

  • 김유성;강주원;이준호
    • 한국공간구조학회논문집
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    • 제20권4호
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    • pp.159-167
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    • 2020
  • The resilience performance evaluation method of a structure can evaluate the ability to recover after an earthquake disaster, and this study deals with the consideration and introduction of the resilience performance evaluation method. The resilience evaluation method can be expressed as a quantified number by constructing a loss estimation model and a recovery evaluation model. The recovery evaluation model should consider downtime in addition to the repair time, and the loss estimation model should consider not only direct loss to structures and non-structures, but also indirect loss due to functional loss of the building. In addition, to build a loss estimation model, the structure should be simplified to perform an efficient analysis. Therefore, in this study, the equivalent terminal induction system proposed cantilever-type and rahmen-type SDOF, and it is evaluated somewhat conservatively compared to the example structure, and it is judged that there is a need to improve the hysteresis characteristics by applying the stiffness reduction factor of the SDOF model.

154 kV 3상 전력 케이블의 상호작용에 따른 금속 Sheath에서 발생하는 와전류 손실 분석 (Analysis of Eddy Current Loss Considering Interaction Effect in Metal Sheath of 154 kV Three Phase Power Cable)

  • 임상현;김기병;박관수
    • KEPCO Journal on Electric Power and Energy
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    • 제6권4호
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    • pp.389-392
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    • 2020
  • 전력 케이블에서 발생하는 손실을 정확히 예측하기 위해서는 금속 시스에서 발생하는 와전류 손실에 대한 분석이 필요하다. 동손의 경우 도체의 저항과 전류에 의하여 쉽게 계산이 되지만 금속 시스에서 발생하는 와전류의 경우 측정 및 예측이 어렵기 때문이다. 이를 위하여 선행연구에서는 단상 케이블에서 발생하는 와전류 손실을 분석하였지만 실제 환경에서는 3상이 대부분 사용되기 때문에 적용하기에는 한계가 존재한다. 그러므로 본 논문에서는 3상 케이블의 금속 시스에서 발생하는 와전류 손실에 대하여 발생 원인에 따라 이론적으로 분석하고 전자기 수치 해석을 통하여 삼각 배열과 수평배열에서 발생하는 와전류 손실을 예측하였다.

Micro-CT analysis of LPS-induced Alveolar Bone Loss in Diabetic Mice

  • Park, Hae-Ryoung;Park, Byung-Ju
    • International Journal of Oral Biology
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    • 제37권3호
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    • pp.85-90
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    • 2012
  • Periodontal disease induces an increased incidence of tooth loss, particularly in cases with an associated loss of alveolar bone and periodontal ligaments. In this study, alveolar bone loss was detected by micro-computed tomography (CT) following exposure to E. coli lipopolysaccharide (LPS) in a streptozotocin (STZ)-induced diabetic mouse model. A 10 mg/ml dosage of E. coli LPS was applied between the first, second and third molars of the mice three times a week for 10 weeks. The loss of periodontal ligaments and alveolar processes was then evaluated by micro-CT using two and three dimensional microstructure morphometric parameters. In the diabetic mice, E. coli LPS induced the destruction of periodontal ligaments and loss of alveolar process spaces. The distances between periodontal ligaments were significantly widened in the STZ-LPS group compared with the untreated STZ group. The 10 mg/ml exposure to E. coli LPS in the STZ mice also resulted in a significant decrease in the alveolar bone volume fraction. The results of our study suggest that alveolar bone loss can be readily detected by volumetric micro-CT analysis as an increase in the distance between periodontal ligaments and in the alveolar process length.

A Study on the Loss Reduction Method of Reinforcing Bar through Case Study

  • Park, U-Yeol;Jung, Hyeon-Ok;Kang, Tai-Kyung;Cho, Hun-Hee
    • 한국건축시공학회지
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    • 제10권4호
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    • pp.123-132
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    • 2010
  • Rebar work accounts for approximately 30% of the total construction costs for rebars and concrete. Recently, the high rising prices of rebars have become one of the principle factors of rising construction costs. Therefore, construction companies are putting much effort into loss reduction of rebars. Consequently, in this study, we wished to present loss reduction methods of rebars before the preparation of the placing drawings. To devise such methods, we collected previous case studies and analyzed methods that were applied for loss reduction. As a result of the analysis, we were able to find the following methods for loss reduction of rebars: method of reducing the number of splices at the mat foundation, method of reducing splice length at the internal columns or walls of the underground parking lot, method of reducing cap-ties of internal beams of basement floors excluding perimeter beams, and method of reducing anchorage length at the internal column or wall of the underground parking lot. Based on those analysis results, we presented our own loss reduction methods of rebars. Applying our methods resulted in considerable loss reduction.

Usefulness of Estimated Height Loss for Detection of Osteoporosis in Women

  • Yeoum, Soon-Gyo;Lee, Jong-Hwa
    • 대한간호학회지
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    • 제41권6호
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    • pp.758-767
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    • 2011
  • Purpose: This study was done to examine the threshold value of estimated height loss at which the risk of osteoporosis increases and to verify its discriminative ability in the detection of osteoporosis. Methods: It was conducted based on epidemiological descriptive methods on 732 Korean women at a public healthcare center in Seoul between July and November 2010. ANOVA, Pearson correlation, logistic regression analysis and receiver operating characteristics (ROC) curve were used for data analysis. Results: There was an age-related correlation between bone mineral density (lumbar spine: F=37.88, p<.001; femur: F=54.27, p<.001) and estimated height loss (F=27.68, p<.001). Estimated height loss increased significantly with decreasing bone mineral density (lumbar spine: r=-.23, p<.001; femur: r=-.34, p<.001). The odds ratio for the point at which the estimated height loss affects the occurrence of osteoporosis was found to increase at a cut-off value of 2 cm and the area under ROC curve was .71 and .82 in lumbar spine and femur, respectively. Conclusion: The optimal cut-off value of the estimated height loss for detection of osteoporosis was 2 cm. Height loss is therefore a useful indicator for the self-assessment and prognosis of osteoporosis.

형상 축소된 연소기의 열손실 및 소염해석 모델 (Thermodynamic Modeling of Heat Loss and Quenching in a Down Scaled Combustor)

  • 이대훈;권세진
    • 대한기계학회논문집B
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    • 제26권7호
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    • pp.919-926
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    • 2002
  • Down scaled combustor undergoes increased heat loss that results in incomplete combustion or quenching of the flame as a consequence. Therefore, effect of enhanced heat loss should be understood to design a MEMS scale combustion devices. Existing combustion models are inadequate for micro combustors because they were developed for analysis of regular scale combustor where heat loss can be ignored during the flame propagation. In this research a combustion model is proposed in order to estimate the heat loss and predict quenching limit of flame in a down scaled combustor. Heat loss in the burned region is expressed in a convective form as a product of wall surface area, heat transfer coefficient and temperature difference. Comparison to the measurements showed satisfactory agreement of the pressure and temperature drop. Quenching is accounted for by introducing a correlation of quenching parameter and heat loss. The present model predicted burnt fraction of gases with reasonable accuracy and proved to be applicable in thermal design of a micro combustor.

냉장고 가스켓 형상 변화에 따른 냉장고 열손실 저감 효과 (The Effect of Gasket Shape on Heat Loss Reduction in a Refrigeration)

  • 하지수;정광수;김태권;김경호;김석로
    • 설비공학논문집
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    • 제21권5호
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    • pp.305-310
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    • 2009
  • The amount of heat loss of a refrigerator through the gasket is nearly 30% of total refrigerator heat loss. In this paper, quantitative evaluation analysis of heat loss through gasket is established with numerical heat transfer analysis. Extending the gasket shape to protect the heat loss from the gasket, power consumption is measured by using real refrigerator in a temperature and humidity chamber and suggest the gasket shape to reduce the heat loss. From the present result of the numerical simulation of heat transfer and experiment with varying gasket shape, we are able to reduce the heat loss about 20-40% by using extended gasket and the power consumption can be reduced about 5%.

다구찌 품질손실개념에 의한 다특성치 품질손실함수 도출의 분석적 접근방법 (An Analytical Approach to Derive the Quality Loss Function with Multi-characteristics by Taguchi's Quality Loss Concept)

  • 배후석;임채관
    • 품질경영학회지
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    • 제48권4호
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    • pp.535-552
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    • 2020
  • Purpose: The main theme of this study is to derive a specific quality loss function with multiple characteristics according to the same analytical structure as the single characteristic quality loss function of Taguchi. In other words, it presents an analytical framework for measuring quality costs that can be controlled in practice. Methods: This study followed the analytical methodology through geometric, linear algebraic, and statistical approaches Results: The function suggested by this study is as follows; $$L(x_1,x_2,{\cdots},x_t)={\sum\limits_{i=1}^{t}}k_i\{x_i+{\sum\limits_{j=1}^{t}}\({\rho}_{ij}{\frac{d_i}{d_j}}\)x_j\}x_i$$ Conclusion: This paper derived the quality loss function with multiple quality characteristics to expand the usefulness of the Taguchi quality loss function. The function derived in this paper would be more meaningful to estimate quality costs under the practical situation and general structure with multiple quality characteristics than the function by linear algebraic approach in response surface analysis.

압전 지능 구조물을 이용한 통계적 에너지 해석 기법 (Application of Piezoelectric Smart Structures for Statistical Energy Analysis)

  • 김재환;김정하;김재도
    • 소음진동
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    • 제11권2호
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    • pp.257-264
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    • 2001
  • In this research, piezoelectric smart structures are applied for SEA(Statistical Energy Analysis), which is well known approach for high frequency analysis. A new input power measurement based on piezoelectric electrical power measurement is proposed and compared with the conventional method in SEA. As an example, a simple aluminum beam on which piezoelectric actuator is attached is considered. By measuring the electrical impedance and electrical current of the piezoelectric actuator, the electrical power given on the actuator is found and this is In turn converted into the mechanical energy. From the measured value of the stored energy of the beam, the Internal loss factor is calculated and this value shows a good agreement with that given by the conventional method as well as the theoretical value. To compare the coupling loss factor, L-shape beam system which consists of a aluminum beam subsystem and a steel beam subsystem coupled by three pin is taken as second example. The input power and stored energy of each subsystem are found by the proposed approach. The coupling loss factor found by the electrical input power obtained from the piezoelectric actuator exhibits similar trend to the value found by the conventional method as well as the theoretical value. In conclusion, the use of SEA for high frequency application of piezoelectric smart structures is Possible. Especially, the input power that is essential for SEA can be found accurately by measuring the electrical input power of the piezoelectric actuator.

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