• Journal of Mechanical Science and Technology
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• 제18권8호
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• pp.1388-1400
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• 2004

Problems with the control, oscillatory motion and compliance of pneumatic systems have prevented their widespread use in advanced robotics. However, their compactness, power/weight ratio, ease of maintenance and inherent safety are factors that could be potentially exploited in sophisticated dexterous manipulator designs. These advantages have led to the development of novel actuators such as the McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle Manipulators. However, some limitations still exist, such as a deterioration of the performance of transient response due to the changes in the external inertia load in the pneumatic artificial muscle manipulator. To overcome this problem, a switching algorithm of the control parameter using a learning vector quantization neural network (LVQNN) is newly proposed. This estimates the external inertia load of the pneumatic artificial muscle manipulator. The effectiveness of the proposed control algorithm is demonstrated through experiments with different external inertia loads.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1914-1919
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• 2006

Recently, the microrobots powered by biological muscle actuators were proposed. Among the biological muscle actuators, frog muscle is well known as a good muscle actuator and has a large displacement, actuation forces and piezoelectric properties. Therefore, for the application of the biomimetic microrobot, this paper reports the electromechanical properties of frog muscle. First of all, the experimental setup has been established for measuring generative force of the frog muscle. Through the various electrical stimulating inputs to the frog muscle, we measured the contractile force of the frog muscle. From the measuring results, we found that the actuating contractile force responses of the frog muscle are determined by the amplitude, frequency, duty ratio, and wave form of the stimulation signal. This study will be beneficial for the development of the microrobot actuated by frog muscle.

• 한국응용과학기술학회지
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• 제37권3호
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• pp.604-612
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• 2020

The purpose of this study is to analyze the level of obesity and sarcopenia among chronic obstructive pulmonary disease(COPD) patients in Korea. The current study recruited 75 patients with COPD who visited the department of respiratory medicine at J University Hospital in J-do. Height, body weight, waist circumference, and hip circumference were measured, and body composition, muscle strength, and flexibility were assessed. The levels of obesity were classified with body mass index(BMI), waist-hip circumference ratio(WHR) and percent body fat, and sarcopenia was classified with the value of skeletal muscle mass and muscle strength by Asian Working Group for Sarcopenia. In results, it was found that the level of obesity was very high as 43% by BMI, 88% by WHR, and 64% by percent body fat. The lower level of muscle strength was 15.50% in males and 23.50% in females. The lower level of muscle mass was 24.10% in males and .00% in females. Males who had one sarcopenia factors were 22.40%, and females were 23.50%, respectively. Males with sarcopenia were 6.90%, and females were .00%. In conclusion, regular resistance exercise is essential not only for the development of motor skills, but also for the normalization of skeletal muscle function and prevention of muscle dystrophy among COPD patients.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.640-647
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• 2008

Breed differences in adult animals are determined during fetal development. If interventions are to be developed that influence growth of muscle and fat, it is important to know at which time during gestation breed differences appear and are fixed. The objective of this study was to characterize fetal development in cattle of different breeds. Pregnant cows of 4 cattle breeds with different growth impetus and muscularity were slaughtered under normal processing conditions and the fetuses were removed. German Angus, a typical beef cattle; Galloway, a smaller, environmentally resistant beef type; Holstein Friesian, a dairy type; and Belgian Blue, an extreme type for muscle growth were used. Fetuses of each breed were investigated at 3, 6, and 9 mo of gestation. Fetuses were weighed and dissected into carcass, organs, and muscles. Body fat weight was obtained using the Soxhlet extraction method. Fetal weight increased most rapidly in the third trimester of gestation mainly due to the accelerated muscle and fat deposition. The organ weight to body weight (BW) ratios decreased and the muscle and fat weight to BW ratios increased. At 3 mo of gestation, Galloway fetuses had the significantly smallest BW, half-carcass weight, leg weight, organ weight, muscle weight and shortest leg length. In contrast, Holstein fetuses had the significantly greatest BW, liver, kidney, and lung weights and significantly longest leg length among the 4 breeds, but no differences between Holstein Friesian and Belgian Blue were detected in half-carcass and leg weight. Indeed, Belgian Blue fetuses had the significantly greatest half-carcass weight, leg weight, and muscle weight at 9 mo of gestation, and Galloway had a significantly greater body fat to BW ratio than Holstein Friesian and Belgian Blue. These differences were not evident at 3 and 6 mo of gestation. These data show that the profound increase of tissue and organ weights occurred in later gestation in cattle fetuses even though breed differences were evident as early as 3 mo of gestation. Depending on the tissue of interest, impacting fetal growth likely needs to occur early in gestation before the appearance of breed-specific differences.

• 한국수산과학회지
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• 제44권6호
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• pp.785-790
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• 2011

This study investigated the nutritive quality of olive flounder Paralichthys olivaceus fed either moist pellet (MP) or moist pellet mixed with mushroom extract (MPME) for 6 months. There was no significant difference in crude protein or extractive nitrogen in the muscle of flounder fed MP versus MPME (P > 0.05). The total amino acid content in the muscle of flounder fed MP was $15.22{\pm}5.24$ g/100 g, compared to $19.90{\pm}2.90$ g/100 g for flounder fed MPME. Essential amino acid content was $7.04{\pm}2.21$ g/100 g in the muscle of flounder fed MP versus $8.94{\pm}2.50$ g/100 g for MPME. Total amino acid content was higher in the muscle of olive flounder fed MPME, while essential amino acid content was higher in flounder fed MP. The ratio of non-essential amino acids to essential amino acids was $0.86{\pm}0.07$ for flounder fed MP and $0.81{\pm}0.08$ for flounder fed MPME. There was no significant difference in free amino acid content and fatty acid composition. The breaking strength of muscle of olive flounder fed MP was higher ($1.44{\pm}0.51\;kg/cm^2$) than in flounder fed MPME ($1.29{\pm}0.30\;kg/cm^2$). There was no evidence that dietary additives, such as mushroom extract, increase growth rate or nutritive quality of olive flounder.

• 한국전문물리치료학회지
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• 제27권3호
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• pp.191-198
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• 2020

Background: Stroke patients experience multiple dysfunctions that include motor and sensory impairments. Therefore, new intervention methods require a gradational approach depending on functional levels of a stroke patient's activity and should include cognition treatment to allow for a patient's active participation in rehabilitation. Objects: This study investigates the effect of integrated revision of electrical sensory stimulation, which stimulates somatosensory and action observation training, which is synchronized cognition intervention method on stroke patients' functions. Methods: Twenty-one stroke patients were randomized into two groups. The two groups underwent twenty minutes of intervention five times a week for three weeks. This study used an electromyogram to evaluate symmetric muscle activation of lower extremities and muscle onset time when performing sit to stand before and after intervention. A weight-bearing ratio was used to evaluate the weight-bearing of the affected side in a sit to standing. To evaluate sit to stand performance ability, this study performed five timed sit to stand tests. Results: The two groups both showed statistically significant improvement in muscle onset time of lower extremity, static balance ability in a standing position, and sit to stand performance after the intervention (p < 0.05). In addition, the action observation and synchronized electrical sensory stimulation group showed significant improvement in symmetric muscle activation of lower extremities and weight-bearing ratio of the affected side (p < 0.05). Conclusion: action observation and synchronized electrical sensory stimulation (AOT with ESS) can have positive effects on a stroke patient's sit to stand performance, and the intervention method that provides integrated AOT with ESS can be used as new nervous system intervention program.

• 한국운동역학회지
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• 제24권1호
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• pp.35-42
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• 2014

Tendon elasticity is an important factor affecting muscle function and thus human movements. It has been reported that the mechanical properties of tendon are adaptable to external loading condition. Based on the adaptability of muscle and tendon to external loading conditions, one can assume that there might be an optimum ratio between muscle strength and tendon stiffness. The present study aimed to investigate whether there is correlation between plantar flexor muscle strength and stiffness of the achilles tendon (AT). Twenty two male subjects (age: $23.2{\pm}1.5yrs$, height: $175.5{\pm}6.2cm$, weight: $75.4{\pm}9.8kg$) performed maximum voluntary isometric plantarflexion on a custom-built dynamometer and muscle-tendon junction of the medial gastrocnemius muscle was simultaneously monitored using a real-time ultrasound imaging machine. The averages of muscle force and tendon stiffness were $366.38{\pm}79.37N$, $35.34{\pm}10.42N/mm$, respectively. Significant positive correlation was observed between muscle strength and tendon stiffness (r=0.8507), indicating that the muscle force is proportional to tendon stiffness. The results might have been used in computational modeling and criterion of training progress level in the fields of training and rehabilitation.

• 한국패류학회지
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• 제28권3호
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• pp.215-223
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• 2012

한국 서해안 해역에서 2011년 9월부터 2012년 1월까지 수평망식으로 양성한 굴의 산란기 이후 생태 생리학적 변화를 조사하였다. 조사 지역은 충남 태안 연안의 의항, 신두리, 이원의 두 곳을 선정하여 생식소지수, 조직학적 분석, 생식소와 폐각근 내의 RNA/DNA의 양과 비, condition index (CI), 연체부지수 등을 분석하여 건강도를 판정하였다. 연구결과 의항에서 수평망식으로 양식한 굴은 다른 지역의 굴과 생리학적 차이를 보였다. 즉, 폐각근 내 RNA/DNA의 양 및 비가 조사기간 동안 지속적으로 감소하였고 가장 낮은 CI와 연체부지수를 보였다. 이원지역의 St. 1과 2에서 양식한 굴은 산란기 이후 빠른 회복력을 보여 RNN/DNA가 증가하였고, 연체부지수와 CI 또한 10월까지 급격히 증가한 이후 감소하는 것으로 나타났다. 신두리 지역의 굴은 연체부지수와 CI가 10월까지 급격하게 감소하였다. 그러나 이러한 건강도 판정요소와는 다르게 폐각근 내 RNA/DNA 비는 단백질의 증가 양상처럼 10월까지 지속적으로 증가하는 것으로 조사되었다. 특이한 점은 신두리와 이원의 St. 1에서는 12월까지도 부분방출기의 개체가 관찰이 되었다. 모든 결과를 종합하여 볼 때 본 연구에서 사용된 RNA/DNA 양과 비의 변화, 연체부지수, CI 등의 간단한 지표만으로도 양식 굴의 건강상태, 산란 후 회복과정에 관한 정보 취득이 가능하였다. 따라서 이와 같은 자료를 통하여 우량종패 생산을 위한 굴 어미관리가 가능하고, 또한 소비자들이 선호할 수 있는 양질의 굴 생산이 가능할 것으로 판단되므로 향후에도 다년간 연구조사가 필요할 것으로 생각된다.

• 대한물리의학회지
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• 제19권3호
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• pp.47-54
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• 2024

PURPOSE: This study aimed to identify the potential clinically predictive indicators of the age-related loss of skeletal muscle mass (ALSMM) in middle-aged women. METHODS: The data from a cross-sectional study involving 2,066 community-dwelling female participants aged 40 to 49 years were analyzed. Complex sampling analyses were used to ensure a nationally representative analysis, incorporating the individual weights provided by KNHANES. This approach accounted for the stratified, clustered, and multistage probability sampling design of the survey. The participants were screened for ALSMM, and various potential predictive indicators were assessed, including age, height, weight, body mass index, waist circumference, skeletal muscle mass index, smoking and drinking status, systolic and diastolic blood pressure, fasting glucose levels, triglyceride levels, and cholesterol levels. RESULTS: Significant potential predictive indicators for ALSMM included height, weight, body mass index, waist circumference, skeletal muscle mass index, and fasting glucose (p < .05). The systolic blood pressure, diastolic blood pressure, triglyceride levels triglyceride, and drinking and smoking status were found to be non-significant variables (p > .05). CONCLUSION: The study identified the potential predictive indicators for ALSMM among community-dwelling middle-aged women. These findings enhance the current understanding of ALSMM and highlight the potential predictive indicators associated with its development in middle-aged women.

• 한국운동역학회지
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• 제21권3호
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• pp.361-368
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• 2011

The purpose of this study was to investigate the effect of isometric hip adduction and abduction on the muscle activities of vastus medialis oblique(VMO) and vastus lateralis(VL) during leg squat exercises. This study consisted of 21 healthy subjects who had no medical history of anterior knee pain or lower extremity disorders. The ball and belt were used to isometrically adduct and abduct the hip joint during the leg squat exercise, respectively. The surface electromyograms of VMO and VL were analyzed, and the findings were used to calculate the VMO:VL ratio during 3 different quadriceps-strengthening exercises(leg squat, LS leg squat with isometric hip adduction, LSHD leg squat with isometric hip abduction, LSHB). The muscle activities of VMO and VL and the VMO:VL ratios were compared using the paired t-test with Bonferroni adjustment. The results showed that the muscle activities of VMO and VL during LSHD were greater than those during LSHB. The VMO:VL ratio was the highest during LSHD. This finding suggests that LSHD using a ball is more effective than LS and LSHB in selectively increasing the muscle activities of VMO. Therefore, we suggest that leg squat exercise with isometric hip adduction using a ball would be useful for maintaining correct patella tracking and for selectively strengthening VMO.