• Title/Summary/Keyword: pass balance control

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Computation of Compact Heat Exchanger Performance by the Heat Exchangelet Method : Effect of Tube-to-tube Conduction along the Fin (미소열교환기법에 의한 밀집형 열교환기의 성능 계산 : 핀을 통한 튜브간 전도의 영향)

  • 성시경;송태호;최영철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.5
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    • pp.494-501
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    • 2000
  • Effectiveness of a 3-pass plate finned-tube heat exchanger is calculated using heat exchangelet method by changing the shape of fin and the arrangement of tubes. The alternative refrigerant R134a is taken in this study. Conduction between neighboring tubes along the fin is taken into account in addition to convection between the fin and the surrounding air. Governing equations are obtained by using energy balance in a small control volume containing a tube and fins. They are numerically solved following the tube. Effect of tube-to-tube conduction is investigated in single-phase and two-phase flows with various fin shapes and arrangements of tubes. Improvement of effectiveness by fin perforation is studied too. The results shows that perforating fins, increasing the number of tubes, and increasing the distance between neighboring tubes at the same fin area enhance the effectiveness.

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Lower Extremity Muscle Activity on the Obstacle Gait in Older Parkinson Diseases (파킨슨 환자들의 장애물 보행 향상을 위한 하지의 근육 활동 규명)

  • Lim, Bee-Oh;Kim, Mi-Young
    • Korean Journal of Applied Biomechanics
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    • v.17 no.4
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    • pp.141-148
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    • 2007
  • Falls associated with tripping over an obstacle can be dangerous, yet little is known about the strategies used for stepping over obstacles in older Parkinson disease. The purpose of this study was to investigate the lower extremity muscle activity on the obstacle gait according to obstacle height in older Parkinson diseases. The obstacle gait of 7 older Parkinson disease was examined during a 5.0 m approach to, and while stepping over, obstacles of 0, 25, 52, and 152mm. Seven pairs of surface electrodes(Noraxon MyoResearch, USA) were attached to the right-hand side of the body to monitor the adductor longus(AL), gluteus medius(GME), gluteus maximus(GMA), biceps femoris(BF), rectus femoris(RF), gastrocnemius(GA), tibialis anterior(TA). Electromyography data were filtered using a 10Hz to 350 Hz Butterworth band-pass digital filter and normalized to the maximum value in the analyzed phases. A one-way ANOVA for repeated measures was employed for selected electromyography variables to analyze the differences of the height of four obstacles. The results showed significant differences between 0.0mm and 25, 52, and 152mm obstacle height in TA and GA activities during the second phase(swing phase). But the more increase obstacle height, the more not increase the muscle activities. This means that the Parkinson disease stepping over obstacle inefficiency. To prevent and reduce the frequency of falls, elderly Parkinson disease maintained and improved their balance, muscular strength, neuromuscular control and mobility.

The correlation between the physical power of golf players and the Titleist Performance Institute Level 1 test

  • Kim, Jaeeun;Yim, Jongeun;Do, Kwangsun
    • Physical Therapy Rehabilitation Science
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    • v.7 no.1
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    • pp.13-17
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    • 2018
  • Objective: This was a correlation study for predicting the power to improve the distance of golf players and developing an effective power program. Design: Cross-sectional study. Methods: The subjects of this study were 24 healthy males and females in their 20s and 30s who were golf athletes living in Seoul and Gyeonggi-do. In the Titleist Performance Institute (TPI) Level 1 test, the twelve swing characteristics include components of stability, mobility, body conditioning ability, and balance. The power test consisted of a vertical jump (VJ) in order to examine the power of the lower body, the seated chest pass (SCP) was used to examine upper body power, and the sit up and throw (SUAT) was used to examine the power of the upper body and core for the TPI Level 2 test. Results: The results of this study showed that the 90/90 was correlated with VJ, SUAT, and SCP scores (p<0.05). Single leg stance was correlated with VJ, SUAT, over head deep squat, and bridge with leg extension were correlated with VJ (p<0.05). The toe touch was correlated with SUAT results (p<0.05). Conclusions: The results of this study showed that the TPI Level 1 test and power test were correlated with the performance of the golf players. Future studies have shown that fitness program development and further research are needed.

A Study on Oriental Medical Diagnosis of Musculoskeletal Disorders using Moire Image (Moire 영상을 이용한 근골격계 질환의 한의학적 진단에 관한 연구)

  • Lee Eun-Kyoung;Yu Seung-Hyun;Lee Su-Kyung;Kang Sung-Ho;Han Jong-Min;Chong Myong-Soo;Chun Eun-Joo;Song Yung-Sun;Lee Ki-Nam
    • Journal of Society of Preventive Korean Medicine
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    • v.4 no.2
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    • pp.72-92
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    • 2000
  • This research has conducted studies on an Oriental medicine-based method of diagnosing of occupational musculoskeletal system diseases. This researcher has searched through existing relevant medical literature. Also, this researcher has worked on a moire topography using moire topography. In this course, this researcher has reached the following conclusion in relation to the possibility of using a moire topography as a diagnosing device of musculoskeletal system diseases under Oriental medicine . 1 The Western medicine outlines its criteria of screening occupational musculoskeletal system diseases as follows A. The occupational musculoskeletal diseases must clearly include one or more of the subjective symptoms characterized by pain, hypoesthesia dysaesthesia, anaesthesia. etc . B, There should be clinically admitted objective observations and diagnosis outlining that the disease concerned shows symptoms such as tenderness, induration. and edema that can appear with occupational musculoskeletal system diseases. dyscinesia should be admitted with the disease concerned, or there should be observations and diagnosis outlining that abnormality exists in electric muscular or nervous diagnosis and examination . C. It should be admitted that prior to the occurrence of symptoms or observations and diagnosis on musculoskeletal system-related diseases, a patient has been engaged in works with conditions requiring improper work posture or work movement. That is, this is an approach whereby they see abnormality in the musculoskeletal system come from material and structural defect, and adjust and control abnormality in the musculoskeletal system and secreta . 2. The Oriental medicines sees that a patient develops the pain of occupational musculoskeletal diseases as he cannot properly activate the flow of his life force and blood thus not only causing formation of lumps in the body and blocking the flow of life force and blood in some parts of the body. Hence, The Oriental medicine focuses on resolving the cause of weakening the flow of life force and blood, instead of taking material approach of correcting structural abnormality Furthermore , Oriental medicine sees that when muscle tension builds up, this presses blood vessels and nerves passing by, triggering circulation dyscrasia and neurological reaction and thus leading to lesion. Thus, instead of taking skeletal or neurophysiological approach. it seeks to fundamentally resolve the cause of the flow of the life force and blood in muscles not being activated. As a result Oriental medicine attributes the main cause of musculoskeletal system diseases to muscle tension and its build-up that stem from an individual's long formed chronicle habit and work environment. This approach considers not only the social structure aspect including companies owners and work environment that the existing methods have looked at, but also individual workers' responsibility and their environmental factors. Hence, this is a step forward method. 3 The diagnosis of musculoskeletal diseases under Oriental medicine is characterized by the fact that an Oriental medicine doctor uses not only photos taken by himself, but also various detection devices to gather information and pass comprehensive judgment on it. Thus, it is the core of diagnosis under Oriental medicine to develop diagnosing devices matching the characteristics of information to be induced and to interpret information so induced from the views of Oriental medicine. Diagnosis using diagnosing devices values the whole state of a patient and formal abnormality alike, and the whole balance and muscular state of a patient serves as the basis of diagnosis. Hence, this method, instead of depending on the information gathered from devices under Western medicine, requires devices that provide information on the whole state of a patient in addition to the local abnormality information that X-ray. CT, etc., can offer. This method sees muscle as the central part of the abnormality in the musculoskeletal system and thus requires diagnosing devices enabling the muscular state. 4. The diagnosing device using moire topography under Oriental medicine has advantages below and can be used for diagnosing musculoskeletal system diseases with industrial workers . First, the device can Provide information on the body in an unbalanced state. and thus identify the imbalance and difference of height in the left and right stature that a patient can not notice at normal times. Second, the device shows the twisting of muscles or induration regions in a contour map. This is not possible with existing shooting machines such as X-ray, CT, etc., thus differentiating itself from existing machines. Third, this device makes it possible for Oriental medicine to take its unique approach to the abnormality in the musculoskeletal system. Oriental medicine sees the state and imbalance state in muscles as major factors in determining the lesion of musculoskeletal system, and the device makes it possible to shoot the state of muscles in detail. In this respect, the device is significant. Fourth, the device has an advantage as non-aggression diagnosing device.

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