• 대한물리의학회지
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• 제11권3호
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• pp.65-72
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• 2016

PURPOSE: The purpose of this study is to determine the differences between the muscle activity of cranio-cervical flexion and extension muscles according to the types of tools used through a short-term intervention of cranio-cervical static stabilization exercises using small tools. METHODS: A total of fifteen male and female adults in their 20s who showed forward head posture in the overall body posture measurement system participated in this study. Each subject performed cranio-cervical static stabilization exercises about flexion and extension while using a sling, a foam roller, a TOGU ball, and without tools separately, and the muscle activity of the sternocleidomastoid muscle, scalenus anterior and splenius capitis was measured. Each value was measured for 10 seconds a total of three times. The maximum voluntary isometric contraction value was computed using the average during the middle four seconds. RESULTS: Cranio-cervical flexion exercises using various tool types, the average activity of the sternocleidomastoid and scalenus anterior muscles was significantly higher when applying the TOGU ball (p<.05). According to the results of implementing cranio-cervical flexion exercise using various tools, the maximum muscle activity of the sternocleidomastoid muscle was significantly higher for the TOGU ball (p<.05). CONCLUSION: Based on these results, the provision of an unstable surface using small tools rather than a stable surface is recommended as an exercise scheme for proprioceptive stimulation in a forward head posture. Particularly, we recommend using the TOGU ball for the provision of an unstable surface to increase the muscle activity of the sternocleidomastoid muscle and scalenus anterior.

• The Journal of Korean Physical Therapy
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• 제27권2호
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• pp.106-111
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• 2015

Purpose: Impaired reaching movement is commonly observed in children with cerebral palsy. The purpose of this study was to determine whether the inclination of seat surface can influence the reaching movement in children with spastic diplegic cerebral palsy (CP). Methods: The subjects were 31 children, 16 children with spastic bilateral CP and 15 typically developing (TD) children. The children performed static sitting and forward reaching under three conditions: a horizontal seat surface (Horizontal $0^{\circ}$), a seat surface inclined anterior 15 degrees (Ant $15^{\circ}$), and a seat surface inclined posterior 15 degrees (Post $15^{\circ}$). A 3-axis accelerometer ('ZSTAR3') was used for analysis of the reaching movement. A 3-axis accelerometer was attached on the manubrium of the sternum, lateral epicondyle of the humerus, and styloid process of the ulna. We measured the reaction time, movement time, and data amount during reaching the 8 cm target with an index finger on the three inclined seat surfaces. Results: Reaction time and movement time for CPs showed significant delay; comparing the TD's and CP's amount was significantly greater than the TD's during reaching task (p<0.05). In particular, CP's reaction time and movement time on a seat surface inclined Ant $15^{\circ}$ was significantly more delayed compared with the other seat surfaces (p<0.05). Conclusion: Our results suggest that seat-inclination intervention may provide an ergonomic approach for children with spastic cerebral palsy.

• 대한정형도수물리치료학회지
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• 제7권2호
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• pp.5-22
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• 2001

The purpose of this study was to investigate the balancing training effect on weight bearing ratio and postural sway on the unstable surface for the CVA patients with balance disability. The inclusion criteria were walking independently 20m distances. Eighteen subjects, 4 with right and 14 with left hemiplegic patients were participated in this study. The range of age was from 35 to 75 and the duration from onset time was from 1 to 38 months. The intervention program including balancing training that they were introduced for 10 minutes every other day during 12 weeks to experimental group, and general therapeutic exercise to control group. The result of this study were as following; 1. The balancing training on the unstable surface showed that the postural sway of left/right distribution would appear more effective on sitting with eyes opened. 2. The balancing training on the unstable surface showed that the postural sway of forward/rear distribution, left/right distribution and distance would appear more effective on standing with eyes opened. 3. The balancing training on unstable surface would increase more effective on the weight-bearing ratio of left/right difference and frequency. 4. The balancing training on unstable surface was statistical significant on the postural sway of left/right distribution and area in experimental group. and it was statistical significant on the postural sway of forward/rear distribution, left/right distribution and distance in control group, too.

• 대한통합의학회지
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• 제10권3호
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• pp.131-140
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• 2022

Purpose : Although many studies have explored the effect of seating side angles on the spinal curve and surrounding muscles during seating, only a few studies have investigated the effect of different seating face angles on different lower limb and deep trunk muscles. Therefore, this study investigated the effects of seating surface angles (0 degrees, 10 degree anterior, and 10 degree rear) on lower extremity and deep trunk muscles in healthy adults. Methods : Thirty people were asked to sit once on each seating surface three times during the day, and their muscle thicknesses were measured by ultrasound while sitting. The method of sitting was the same when sitting on the three seating surfaces. Results : From the comparison results of the muscle thicknesses according to the seating surface angles, a significant difference existed in the muscle thicknesses of the vastus medialis, vastus medialis oblique, vastus intermedius, soleus and gastrocnemius (p<.05). However, no significant difference was found in the transversus abdominis, internal obliques, rectus femoris and vastus lateralis (p>.05). Conclusion : Our findings revealed that the lower back load decreases, the leg load increases, and the legs specific muscles are affected as the body tilts forward when sitting on the seating surface inclined forward. Therefore, it is possible to suggest a forwardly inclined seating surface that reduces lower back loads and utilizes the posture-maintaining muscles of the legs when sitting in a person with a poor sitting posture or lower back pain at ordinary times.

• 국제물리치료학회지
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• 제9권4호
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• pp.1619-1625
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• 2018

To examine the changes in pain, the severity of the neck disorder, craniovertebral angle, and muscle activity in young adults with forward head posture. 37 "N" University students in their 20s with forward head posture, including both male and female participants. Measurement of pain, NDI (neck disorder index) craniovertebral angle, and muscle activity were taken before and after the 6 week intervention period. The pain was measured using the visual analog scale. The severity of the neck disorder was measured using the NDI The craniovertebral angle was measured by taking a photo. The muscle activity was measured using surface electromyography. Neck posture correction exercises paired with proprioceptive training is the most effective intervention for reducing pain. Both neck posture correction exercises paired with Kinesio taping or proprioceptive training are effective interventions for addressing neck disability, craniocervical angle, and muscle activity. Neck posture correction exercises paired with Kinesio taping or proprioceptive training are more effective at addressing pain, neck disorder, craniocervical angle, and muscle activity than performing the neck posture correction exercises alone.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.2157-2161
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• 2003

In this paper, the response surface method using three-dimensional Navier-Stokes analysis to optimize the shape of a forward-curved blades centrifugal fan, is described. For numerical analysis, Reynolds-averaged Navier-Stokes equations with standard k-e turbulence model are transformed into non-orthogonal curvilinear coordinate system, and are discretized with finite volume approximations. Due to the large number of blades in forward-curved blades centrifugal fan, the flow inside of the fan is regarded as steady flow by introducing the impeller force models for economic calculations. Linear Upwind Differencing Scheme(LUDS) is used to approximate the convection terms in the governing equations. SIMPLEC algorithm is used as a velocity-pressure correction procedure. Design variables, location of cur off, radius of cut off, expansion angle of scroll and width of impeller were selected to optimize the shapes of scroll and blades. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, the efficiency was successfully improved. It was found that the optimization process provides reliable design of this kind of fans with reasonable computing time

• 지구물리와물리탐사
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• 제5권2호
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• pp.99-107
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• 2002

표면파 기법(SASW, Spectral Analysis of Surface Waves)을 지반공학 분야에 효율적으로 적용하기 위해 모형 응답 알고리듬을 해석적으로 도출하였다. 이 논문에서는 이론적인 분산 곡선 응답 반응을 Aki and Richard에 의해 제안된 운동 응력 벡터(motion stress vector)를 이용하여 미분 방정식을 구성한 후 차분 전개를 통하여 구함으로서 동적 강성도 법이나 전파 행렬법에 비해 간단하고 빠르게 구할 수 있었다. 차분 전개를 통한 이론 분산 곡선 응답 반응 알고리즘으로 2개의 지구 모형에 대해 이론 분산 곡선을 구하여 타당성을 검증하였다. 또한 모형 응답 계산 과정에서 고려하여야 할 주파수 대역에 따른 적절한 모형의 크기에 대하여 고찰한 결과 각 파장의 $1.5\~2$배 이내로 모형의 크기를 결정할 때 경제적이고 안정적인 결과를 얻을 수 있었다.

• 대한금속재료학회지
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• 제48권1호
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• pp.90-100
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• 2010

Micro-conductive patterns were microfabricated on an insulating substrate ($SiO_2$) surface by a selective electroless nickel plating process in order to investigate the formation of seed layers. To fabricate micro-conductive patterns, a thin layer of metal (Cu.Cr) was deposited in the desired micropattern using laser-induced forward transfer (LIFT). and above this layer, a second layer was plated by selective electroless plating. The LIFT process. which was carried out in multi-scan mode, was used to fabricate micro-conductive patterns via electroless nickel plating. This method helps to improve the deposition process for forming seed patterns on the insulating substrate surface and the electrical conductivity of the resulting patterns. This study analyzes the effect of seed pattern formation by LIFT and key parameters in electroless nickel plating during micro-conductive pattern fabrication. The effects of the process variables on the cross-sectional shape and surface quality of the deposited patterns are examined using field emission scanning electron microscopy (FE-SEM) and an optical microscope.

• 한국전문물리치료학회지
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• 제27권4호
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• pp.264-271
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• 2020

Background: Because a forward-leaning posture can cause increased back muscle activity and pain. Therefore, an innovative method to reduce back muscle activity and pain is required. Objects: This study aimed to investigate the effects of a head support on muscle activity and pain in a forward-leaning posture. Methods: A total of 14 male and 16 female students (average age, 21.65 ± 2.37 years; height, 166.15 ± 7.90 cm; and weight, 60.65 ± 9.00 kg) were recruited for the experiment. Two of them were excluded due to musculoskeletal disorders. The muscle activity and pain in the forward-leaning posture were assessed while participants washed dishes for 7 minutes with and without a head support. The condition of using a head support was randomly performed with a 5-minutes break. To confirm a lumbar flexion angle of 30° during the experiment, myoVIDEO was used, and surface electromyography was used to measure muscle activity. Pain was assessed using a 10-point visual analog scale (VAS). The Wilcoxon signed-rank test was used to analyze the data, with p < 0.05 indicating statistical significance. Results: The cervical, thoracic, and lumbar erector spinae muscle activities significantly decreased with the use of the head support, but there was no significant change in the gluteus maximus. There was a significant decrease in the VAS score for the lumbar erector spinae (p < 0.05), but there was no significant change in the VAS score for the cervical region. Conclusion: The use of a head support in a forward-leaning posture reduced cervical, thoracic, and lumbar erector muscle activity and pain. Therefore, it could be recommended during working in a forward-leaning posture, such as during dishwashing, cooking, and working as a factory employee.

• The Journal of the Acoustical Society of Korea
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• 제22권1E호
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• pp.11-18
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• 2003

Non-singular boundary element method (BEM) codes are developed in acoustics application. The BEM code is then used to calculate unknown boundary surface normal displacements and surface pressures from known exterior near field pressures. And then the calculated surface normal displacements and surface pressures are again applied to the BEM in forward in order to calculate reconstructed field pressures. The initial exterior near field pressures are very well agreed with the later reconstructed field pressures. Only the same number of boundary surface nodes (1178) are used for the initial exterior pressures which are at first calculated by Finite Element Method (FEM) and BEM. Pseudo-inverse technique is, used for the calculation of the unknown boundary surface normal displacements. The structural object is a tuning fork with 128.4 ㎐ resonant. The boundary element is a quadratic hexahedral element (eight nodes per element).