• 한국산업보건학회지
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• 제21권4호
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• pp.209-214
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• 2011

Objectives: To assess the risk of pushing or pulling the yarn-carrying cart, the survey was performed in some fiber manufacturing factories. Methods: We selected 6 fiber-twisting factories which agreed to in-site survey of their workplace. To measure both initial and sustained forces of the push-pull tasks, Chatillon CSD500 dynamometer(2004, Ametek, USA) was used. The mean of 3 tests for the same cart was adopted as the measured forces. Height and width of cart, weight of spooled yarns, and distance of movement were also measured. Inspection of cart wheel, moving path, and the actual hand position while moving was done. Results: More than one pushing or pulling task exceeded the push-pull force limits of design goal in 5 factories. Though the cart was not loaded the heaviest weight in the factory, the measured push or pull force exceeded the limits several times. A few cart wheels were worn out and tangled with pieces of yarn. It was also observed some holes in the moving path. Conclusions: While the push-pull task is not included in the 11 scopes of over-burdened work notified by Korean government, it should be recognized as risk factor of work-related musculoskeletal disorders. The maintenance work such as regular change and frequent cleaning of cart wheel, the use of fitting wheel, and flattening of bumpy floor through the moving path should be advised importantly in the worksite management of work-related musculoskeletal disorders.

• 한국정보처리학회논문지
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• 제7권2S호
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• pp.721-732
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• 2000

Multimedia communication systems require not only high-performance computer hardwares and high-speed networks, but also a buffer management mechanism to process many data efficiently. Two buffer handling methods, Push and Pull, are commonly used. In the Push method, a server controls the flow of dat to a client, while in the Pull method, a client controls the flow of data from a server. Those buffering schemes can be applied to the data transfer between the packet receiving buffer, which receives media data from a network server, and media playout devices, which play the recived media data. However, the buffer management mechanism in client-sides mainly support either one of the Push or the Pull method. Consequently, they have some limitations to support various media playout devices. Futhermore, even though some of them support both methods, it is difficult to use since they can't provide a unified structure. To resolved these problems, in this paper, we propose an efficient and flexible Push/Pull buffer management mechanism at client-side. The proposed buffer management scheme supports both Push and Pull method to provide various media playout devices and to support buffering function to absorb network jitter. The proposed scheme can support the various media playback devices using a single buffer space which in consequence, saves memory space compared to the case that a client keeps tow types of buffers. Moreover, it facilitates the single buffer as a mechanism for the absorbing network jitter effectively and efficiently. The proposed scheme has been implemented in an existing multimedia communication system, so called ISSA (Integrated Streaming Service Architecture), and it shows a good performance result compared to the conventional buffering methods in multimedia communication environments.

• Steel and Composite Structures
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• 제35권4호
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• pp.475-494
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• 2020

Presented are experimental results from 24 full-scale push test specimens to study the behaviour of composite beams with trapezoidal profiled sheeting laid transverse to the beam axis. The tests use a single-sided horizontal push test setup and are divided into two series. First series contained shear loading only and the second had normal load besides shear load. Four parameters are studied: the effect of wire mesh position and number of its layers, placing a reinforcing bar at the bottom flange of the deck, normal load and its position, and shear stud layout. The results indicate that positioning mesh on top of the deck flange or 30 mm from top of the concrete slab does not affect the stud's strength and ductility. Thus, existing industry practice of locating the mesh at a nominal cover from top of the concrete slab and Eurocode 4 requirement of placing mesh 30 mm below the stud's head are both acceptable. Double mesh layer resulted in 17% increase in stud strength for push tests with single stud per rib. Placing a T16 bar at the bottom of the deck rib did not affect shear stud behaviour. The normal load resulted in 40% and 23% increase in stud strength for single and double studs per rib. Use of studs only in the middle three ribs out of five increased the strength by 23% compared to the layout with studs in first four ribs. Eurocode 4 and Johnson and Yuan equations predicted well the stud strength for single stud/rib tests without normal load, with estimations within 10% of the characteristic experimental load. These equations highly under-estimated the stud capacity, by about 40-50%, for tests with normal load. AISC 360-16 generally over-estimated the stud capacity, except for single stud/rib push tests with normal load. Nellinger equations precisely predicted the stud resistance for push tests with normal load, with ratio of experimental over predicted load as 0.99 and coefficient of variation of about 8%. But, Nellinger method over-estimated the stud capacity by about 20% in push tests with single studs without normal load.

• 한국전문물리치료학회지
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• 제18권1호
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• pp.1-8
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• 2011

Push-up plus has been advocated for increasing the activity of the serratus anterior muscle, the most critical scapular stabilizer. However, no previous study has reported the possibility of compensatory motion on the part of the pectoralis major, which could substitute for the action of the serratus anterior during push-up plus. The aim of the current study was to investigate the immediate effect of electromyography (EMG) biofeedback of the pectoralis major muscle on the pectoralis major, upper trapezius, and serratus anterior muscles during push-up plus. Fourteen healthy young subjects voluntarily participated in this study; each subject performed push-up plus from the quadruped position, in two conditions (i.e., with or without visual and auditory biofeedback). Surface EMG was used to measure pectoralis major, serratus anterior, and upper trapezius activity. A paired t-test was used to determine any statistically significant difference between the two conditions. Additionally, effect size was calculated to quantify the magnitude of EMG biofeedback in each muscle. Visual and auditory feedback reduced pectoralis major muscle activity significantly (p=.000) and increased the serratus anterior muscle activity significantly (p=.002), but did not induce a significant difference in upper trapezius muscle activity (p=.881). Thus, it is concluded that the visual and auditory feedback of pectoralis major muscle activity can be used to facilitate serratus anterior muscle activity during push-up plus.

• 한국전문물리치료학회지
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• 제26권4호
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• pp.29-34
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• 2019

Background: The serratus anterior is one of the most important muscle for maintaining good scapular alignment in the shoulder joint. The pectoralis major and upper trapezius may also compensate for weak serratus anterior muscles. The push-up plus exercise has been identified as the optimal exercise for maximum activation of the serratus anterior. Objects: The purpose of this study was to examine differences in surface electromyography (EMG) activity of upper trapezius, pectoralis major, and serratus anterior muscles during push-up plus exercises on variously angled surfaces in subjects with winged scapula. Methods: Sixteen subjects with winged scapula (male=5, female=11) volunteered for this study. The subjects performed push-up plus exercise on four different tilt angles, namely $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$. EMG activities in the serratus anterior, upper trapezius, and pectoralis major muscles during performance of push-up plus exercise were measured in all subjects. Data were processed from repeated measures one-way analysis of variance. Results: There was significant difference in the muscle activity of the serratus anterior on the different surface angles (p<.05). The results of the post-hoc analysis showed significantly greater serratus anterior muscle activity on a surface at a $0^{\circ}$ angle than at others tilt angles (p<.05). There was also significant difference in the ratio of serratus anterior to upper trapezius and serratus anterior to pectoralis major across the four surfaces (p<.05), and post-hoc analysis showed significantly greater values on the $0^{\circ}$ surface than on other tilts (p<.05). Conclusion: This study found that performing push-up plus exercises on a flat surface with $0^{\circ}$ and $30^{\circ}$ tilt angle achieves high activation of the serratus anterior muscle for selective strengthening. It can also take into account the sequential application, which is first performed at a $30^{\circ}$ and at a $0^{\circ}$ tilt angle for and effective but not excessive muscle activation.

• 한국산림과학회지
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• 제100권3호
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• pp.327-333
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• 2011

본 연구는 등산객의 건강과 관련된 동기요인과 산림환경이 갖는 유인요인을 도출하고 이들 요인 간의 분석을 통하여 산림휴양공간에 대한 효율적인 관리방안을 제시하는 데 그 목적이 있다. 도봉산, 북한산, 관악산, 청계산을 찾은 등산객 440명에 대해 건강과 관련된 15개의 동기항목 및 11개의 유인항목을 설문조사한 결과, 등산동기요인으로 '질병치료 치유', '정신 사회적 건강', '신체적 건강' 등 3개 요인을, 등산유인요인으로는 '인문환경', '사회경제적 환경', '자연환경' 등 3개 요인을 도출하였다. 요인 간 영향관계 분석결과, 질병치료 치유요인과 신체적 건강요인에 가장 큰 영향을 미치는 유인요인은 자연환경요인으로 나타났으며, 정신 사회적 건강요인에 가장 큰 영향을 미치는 유인요인은 사회경제적 환경요인으로 나타났다.

• 대한방사선기술학회지:방사선기술과학
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• 제45권5호
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• pp.391-396
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• 2022

The purpose of this study was to investigate the effect of cross arms and palms facing forward on spinopelvic parameters during the whole spine lateral radiography. In addition, we would like to present the usefulness of a posture with the palm facing forward during whole spine lateral radiography of the spine using EOS. The subjects of this study were images of a total of 50 patients (18 males, 32 females) who whole spine lateral radiography using the conventional method and the EOS method from October 2020 to March 2021. The posture used in this study was set as 'CAP' for cross arms and 'PUSH' for posture with palms facing forward. In this study, among the spinal stability factors, thoracic kyphosis (thoracic vertebrae 4 to 12), lumbar lordosis (lumbar vertebrae 1 to sacrum 1), sagittal vertical axis, sacral slope, and shoulder flexion angle were compared on average. The mean thoracic kyphosis was 34.52±12.46° for CAP and 28.46±10.81° for PUSH (p<0.01). The lumbar lordosis of CAP was 42.45±17.45°and that of PUSH was 40.56±16.14°(p>0.57). The sagittal vertical axis was 26.59±34.34 mm in CAP and 21.21±35.41 mm in PUSH (p>0.44). In CAP, the sacral slope was 30.96±10.29°, and in PUSH, it was 31.01±10.19° (p>0.98). shoulder flexion angle was 38.31±8.24° for CAP and 26,08±6.71° for PUSH(p<0.01). As a result of this study, the PUSH posture is considered to be a posture that can minimize the shoulder flexion angle and can perform a stable examination while minimizing changes in spino-pelvic parameter.

• 월간포장계
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• 통권128호
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• pp.84-89
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• 2003

• 한국통신학회:학술대회논문집
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• 한국통신학회 1991년도 추계종합학술발표회논문집
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• pp.398-401
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• 1991

• 한국통신학회:학술대회논문집
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• 한국통신학회 1995년도 하계종합학술발표회 논문집
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• pp.628-631
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• 1995