• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.11
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• pp.96-102
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• 2019

Reverse engineering involves duplicating a physical part by measuring and analyzing its physical dimensions, features, and material properties. By combining reverse engineering with three-dimensional (3D) printing, engineers can simply fabricate and evaluate functional prototypes. This design methodology has been attracting increasing interest with the advent of the Fourth Industrial Revolution. In the present study, we apply reverse engineering and 3D printing technologies to evaluate a fabricated automotive inner ring prototype. Through 3D printing, inner rings of various densities were prepared. Their physical dimensions were measured with a 3D scanning system. Of our interest was the effect of inner ring density on the physical dimensions of the fabricated prototype. We compared the design dimensions and physical dimensions of the fabricated prototypes. The results revealed that even the 20% density of inner ring was effective for 3D printing in terms of satisfying the design requirements.

• Korean Journal of Exercise Nutrition
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• v.23 no.4
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• pp.36-42
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• 2019

[Purpose] The study aimed to determine the effects of bone-specific physical activity on body composition, bone mineral density (BMD), and health-related physical fitness in middle-aged women. [Methods] One hundred eighty-six middle-aged women aged 31-49 years participated in this study. The subjects were divided into tertile groups according to the level of physical activity (low-score group, n=62; middle-score group, n=62; high-score group, n=62). Bone-specific physical activity participation was assessed using the bone-specific physical activity questionnaire. Body composition and BMD were measured using dual-energy X-ray absorptiometry. Health-related physical fitness test included isometric muscle strength (grip strength), muscular endurance (sit-ups), flexibility (sit and reach), and cardiorespiratory fitness (maximal oxygen uptake [VO_2max]). [Results] The high-score group had a significantly higher fat-free mass (p=.045, partial eta-squared value[η_p²]=.033) than the middle- and low-score groups, whereas the high-score group had significantly lower percent body fat (p=.005, η_p²=.056) than the other two groups. Whole-body BMD (p=.034, η_p²=.036) and lumbar BMD (p=.003, η_p²=.060) were significantly higher in the high-score group than in the low-score group. The high-score group performed significantly better for grip strength (p=.0001, η_p²=.101), sit-ups (p=.0001, η_p²=.108), and VO_2max (p=.0001, η_p²=.092) than the other two groups. [Conclusion] The present study suggests that bone-specific physical activity could be useful in improving body composition, BMD, and health-related physical fitness in middle-aged women, significantly enhancing their BMD and health conditions.

• Physical Therapy Korea
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• v.13 no.1
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• pp.47-53
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• 2006

Since ultrasound has different reflections depending on components of organization, analysis of ultrasound images of skeletal muscle can offer both quantitative and qualitative reports as concerns skeletal muscle structure. This study is focused on the ultrasound method for evaluating the structural characteristics of skeletal muscle and also conducted to examine its practicality. After obtaining images of the elbow flexors from an ultrasound image device with 88 normal subjects whose ages were between twenty and seventy years old (44 men and 44 women), muscular density and white area index (WAI) which indicated structural characteristics of skeletal muscle were analyzed with gray scale analysis. The study examined correlations between subject's age and items which obtained from measuring ultrasound images and the differences in relations to sex and age. Muscular density and WAI had a high correlation with age and were significantly increased in men and women with greater age. The quantitative evaluation method of skeletal muscle structure which analyzed the ultrasound images has high practicality because it is a non-invasive method which complements physical therapy diagnosis and research methods and promotes functionality evaluation.

• Journal of Digital Convergence
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• v.16 no.2
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• pp.375-383
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• 2018

The purpose of this study was to investigate the effect of exercise training on health-related physical fitness and osteoporosis after 12 weeks of combined training for adults with intellectual disabilities diagnosed with obesity and osteoporosis. The subjects conducted a combined training program consisting of aerobic exercise and strength training twice a week for 12 weeks. Body composition and bone mineral density were measured before exercise, 6, 12 weeks, and health-related physical fitness was measured before and after exercise. Body weight and body fat decreased after exercise and bone density increased after exercise compared to before exercise. Muscle strength, muscle endurance and flexibility were improved after exercise compared to before exercise. It was confirmed that the 12 week compound training increased the leg strength and improved the functions such as walking and running, and increased the health-related fitness and increased bone mineral density.

• The Journal of Korean Physical Therapy
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• v.17 no.1
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• pp.27-42
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• 2005

This study aims to investigate the effect of Early Weight Bearing and Vibration Exercise and is focusing on the difference between changes if experimental before and after on 30 stroke patients. The obtained results are as follows; First, the chang due to Early Weight Bearing and Vibration in the comparison of experimental duration, Early Weight Bearing and Vibration Exercise showed improvement of Bone Density(P<.05). Second, in the comparison of change according to Early Weight Bearing and Vibration Exercise, Bone Density was significantly changed between two experimental group(P<.05). Third, the chang due to Early Welght Bearing and Vibration Exercise, Bone Density of sound femoral head and affected femoral head was significantly changed(P<.05). Fourth, the chang due to Early Weight Bearing and Vibration Exercise, Bone Density of femoral head was significantly changed between two experimental group(P<.05).

• The Journal of Korean Physical Therapy
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• v.19 no.6
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• pp.23-30
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• 2007

Purpose: This study examined the correlation between the maximum voluntary isometric contraction (MVIC) and the muscle architecture in the extensor carpi radialis longus muscle during MVIC. Methods: The muscle area, volume were measured using a ultrasound imaging system to obtain the muscle architecture during the MVIC. For the mechanical muscle strength measurements, the MVIC was obtained using a dynamometer. Results: There was a significant correlation between the MVIC and the muscle area (r=0.498, p<0.01) and muscle volume (r=0.602, p<0.001). There was a significant correlation between the MVIC and density (r=-0.429, p<0.05). The area showed significant correlations with the muscle volume (r=0.699, p<0.001) and density (r=-0.429, p<0.05). In addition, there was a correlation between the volume and muscle density (r=0.555, p<0.01). Conclusion: There is close relationship between the MVIC and the muscle architecture in the extensor carpi radialis longus muscle during the MVIC.

• Physical Therapy Korea
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• v.16 no.4
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• pp.31-36
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• 2009

Hemiplegia-induced immobilizatoin and reduction of mechanical loading in chronic stroke limbs are common cause of disuse osteoporosis. The purpose of this study was to investigate the effects of asymmetrical weight bearing on the loss of bone mineral in the individual with chronic stroke. Sixteen hemiplegic patients with strokes were evaluated. The measurements of bone mineral density (BMD) were evaluated with the quantitative ultrasound system on the calcaneus region of the paretic and non-paretic side. Plantar pressure was measured using the Mat-Scan system. The paretic side showed significantly smaller values in the T-score of BMD, and peak value of plantar pressure, which included forefoot, midfoot, and hindfoot, than the non-paretic side (p<.05). Results from the pearson correlation analysis showed statistically significant correlation between the BMD difference and the peak-pressure difference of midfoot pressure (p<.05). This finding indicated that BMD loss depended on decrease of body weight born on the paretic leg.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.38-39
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• 2018

Foame concrete was used to reduce insulation problems and interlayer noise in slab. There have been no studies on the physical properties of foaming agents using foamed concrete,Only the physical properties of foamed concrete mixed with foam agent. It is judged that the density and distribution of Foams will be changed when the pressre is changed when the bubble is formed. In this study to investigate the changes of Foam density and the physical performance of foamed concrete by changing the pressure during Foam formation.

• Economic and Environmental Geology
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• v.21 no.1
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• pp.97-106
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• 1988

The purpose of this study is to collect basic data which are prerequisite for quantitative analysis of coal logging data. The study involves laboratory measurements of physical properties such as seismic velocities (P,S-waves), resitivity and density of domestic and imported foreign coals. The relationships between these properties were analyzed by using cross-plots. Correlation between the physical properties of coal and the results of chemical analysis (calorie, fixed carbon, ash, moisture, volatile matter and sulfur contents) was also studied to obtain ideas about coal quality analysis using logging data. Summarized results are as follows: 1. $V_P$ is exponentialy related to $V_S$. And the average value of $V_P$ is about l.8 times as large as $V_S$. 2. Since coal has very low density compared with surrounding sedimentary rocks, density logging is appeared to be the best method for identifying coal seams and evaluating their qualities. 3. For the case of domestic coals, the ash contents and calorie show a perfect inverse relationship. Since the density increases as increase of ash content with a well-defined functional form, the ash content of domestic coals can be estimated by density measurements. 4. Because of low ash content, low density and high resistivity, foreign coals and domestic lignites are easily distinguished from domestic coals.

• Journal of Forest and Environmental Science
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• v.9 no.1
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• pp.10-18
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• 1993

The study was carried out to investigate the physical (Density, Percentage of latewood, Percentage of pore zone, Mean annual ring width) and mechanical (Compressive strength parallel to the grain, Compression perpendicular to the grain, Shearing strength) properties of some major northern softwoods and hardwoods. The physical and mechanical properties of each species are summerized as Table 2 and the relationship between physical and mechanical factors are discussed. The results of this study were as follows: Density and percentage of latewood are closely related to physical and mechanical properties, but percentage of pore zone and mean annual ring width are remotely related to physical and mechanical properties.