• Title/Summary/Keyword: 좌우운동

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The Effect of Asymmetric Muscle Force in the Lower Extremity on Dynamic Balance on during Drop Landing (하지근력의 좌우 비대칭성이 드롭랜딩 시 동적 안정성에 미치는 영향)

  • Kim, Chul-Ju;Lee, Kyung-Il;Hong, Wan-Ki
    • Korean Journal of Applied Biomechanics
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    • v.21 no.2
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    • pp.173-179
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    • 2011
  • This study aims to analyse difference in biomechanical factors between dominant legs and recessive ones according to muscular imbalance during drop landing targeting talented children in sports. The subjects of the study were ten primary students who are attending to Sports Program for Talented Children organized by C university (age: $12.28{\pm}0.70$ year, height: $1.52{\pm}0.11$ m, and weight: $45.2{\pm}4.9$ kg). Strength legs were classified into dominant side and strengthless legs were classified into non-dominant legs. For three-dimensional analyses of the data collected, 6 video cameras(MotionMaster200, Visol, Korea) were used. To analyse ground reaction force, two force platforms(AMTI ORG-6, MA) were used and to analyse electromyograghy a 8-channeled wireless Noraxon Myoresearch made in USA was used at 1000 Hz for sampling. As a result, it was discovered that the dominants legs controlled knee bending motions more stably than strengthless legs as the maximum vertical ground reaction force was significantly high in dominant legs(p<.05), and joint moment of knee joints of the dominant legs was high(p<.05). Therefore, this study suggested that injury prevention program focusing on muscular balance as well as the existing sports programs for talented children should be developed based on results of the study and it is expected that the results will be useful for improvement of sports programs for talented children.

Measurement of postural instability before and after experiencing a VR system by using a force platform (힘판을 이용한 가상현실 체험 전후 신체동요의 측정)

  • 박재희;김영윤;김은남;김현택;고희동
    • Science of Emotion and Sensibility
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    • v.5 no.4
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    • pp.45-49
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    • 2002
  • Recently, virtual environment systems are used in various application fields such as industry, medicine, and training and education. However, the negative effect, cybersickness including nausea, visual fatigue, and disorientation, could be happened while using VR systems. It prevents VR system from spreading much more. To control the cybersickness, first of all, the objective measurement method should be established. As one of alternative methods, the postural instability could be a measure of cybersickness. In this study, 45 participants' postural sway before and after experiencing a H driving simulator was measured by using a force platform. Especially, we examined if two factors, motion and feedback, could affect on the postural instability The results showed the postural instability slightly increased after experiencing the VR driving simulator. For the factors, the providing of motion synchronized to visual display showed statistical significant decrease in postural sway along lateral side. To check the effectiveness of postural instability as a cybersickness measure, further studies are needed.

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A Study on the Optimization of the Digital Media Service Menu Structure based on the Differentiations of User Experience with special reference to Eye Tracking Test (사용자경험 차이를 고려한 TV(디지털미디어) 서비스 초기메뉴의 구조 최적화 연구 - 시선추적 실험을 중심으로)

  • Lee, Sang-Ho
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.445-452
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    • 2010
  • This paper deals with the exploratory study & experimentation for foundation & theoretical base of menu structuring & design improvement of digital media (IPTV, Digital cable TV) service players. Digital media service providers had been offered many cases of menu structure since their service launched. Researcher set a research topic which verification of eye tracking velocity when media user feels with perceived ease of design and the familiarity. Researcher arrives at a conclusion through as stated above experiment that vertical type of menu and horizontal type of menu are differentiated from the contents characteristics. Research conclusions & implications are strong theoretical base with digital media service players when they planning and designing their service structuring.

FRACTAL DIMENSION OF SIMULATED SEDIMENTS (모의류사의 쪽거리 차원)

  • 김형수;윤용남
    • Water for future
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    • v.27 no.3
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    • pp.115-121
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    • 1994
  • Cohesie sediment movement in estuarine systems is strongly affected by the phenomena of aggregation and flocculation. Aggregation is the process where primary particles are clustered together in tightly-packed formations; flocculation is the process where aggregates and single particles are bonded together to form large particle groups of very low specific density. The size, shape and strength of the flocculants control the rate of deposition and the processes of pollutant exchange between suspended sediments and ambient water. In estuarine waters, suspended sediments above the lutocline form the mobile suspension zone while below the lutocline they form the stationary suspension zone. Suspended particles in the mobile zone are generally in a dispersed state and the controlling forces are the Brownian motion and the turbulent flow fluctuations. In the stationary suspension zone, the driving force is the gravity. This paper discusses the settling and particle flocculation characteristics under quiescient flow conditions. Particles are entering the study domain randomly. Particles in the mobile suspension zone are simulated by using the Smoluchowski's model. Flocs created in the mobil suspension zone are moving into the stationary suspension zone where viscosity and drag effects are important. Utilizing the concepts of the maximum Feret's diameter and the Minkowski's sausage logic, the fractal dimension of the flocs within the stationary suspension is estimated and then compared with results obtained by other studies.

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Heat Flow Characteristics on Type of Heat Transfer Plate for White Smoke Reduction under Uniform Flow Condition (균일유동에서 백연저감용 전열판 형태에 대한 열유동 특성)

  • Son, Jun;Cha, Jae Min;Wang, Zhen Huan;Kwon, Young Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.591-596
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    • 2016
  • Numerical analyses were performed on the heat flow characteristics of a heat transfer plate with six different shapes (basic, rectangle, triangle, wave type) to reduce the level of white smoke at a stack. In this study, to examine the heat transfer performance (heat transfer capacity, pressure drop, turbulence kinetic energy, heat transfer coefficient) on the heat transfer plates, simulations were conducted using the commercial computational fluid dynamics software, ANSYS CFX Ver.14 under uniform flow conditions. The thermal flow phenomenon in a channel with six heat transfer plates could be predicted adequately under uniform flow conditions. The heat transfer capacity, pressure drop, turbulence kinetic energy, and heat transfer coefficient were affected by the flow rate, aspect ratio and plate shape. These results provide guidelines to design an effective heat exchanger with the wave type to reduce white smoke.

Evaluation for Symmetry Ability of One Leg Standing Pose before and after Yoga Training (요가수련전후 한발서기자세의 좌우대칭력 평가)

  • Yoo, Sil
    • Korean Journal of Applied Biomechanics
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    • v.24 no.4
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    • pp.391-397
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    • 2014
  • The purpose of this work is to biomechanically study the effect of the one leg standing pose in yoga.. The work have been done through the evaluation for the left and right symmetry ability of one leg standing pose in the before and after yoga training for the 14 female yoga subject group (height: $164.3{\pm}4.4cm$, mass: $53.4{\pm}6.4kg$, year: $20.0{\pm}0.49yrs$) participated in this experiment. The motions of one leg standing pose were captured with Vicon system and the parameters were calculated with Visual-3D and Ground reaction force system. The results were as followed; - Front and backward COPsd did not show the significant difference, compared the before training with the after. - Left and right COPsd showed the significant difference (p<0.05), compared the before training with the after. - COP distance showed the significant difference (p<0.01), compared the before training with the after. - The asymmetry index of front and backward COPsd did not show the significant difference, compared the before training with the after. - The asymmetry index of left and right COPsd did not show the significant difference, compared the before training with the after. - The asymmetry index of COP distance showed the significant difference (p<0.01), compared the before training with the after. Therefore, the yoga training demonstrated the stable improvement in the one leg standing pose of inferior feet and the positive effect to the left and right symmetry ability.

Total Precipitable Water Fields of Typhoons WALT(9407) & FAYE(9503) Derived from TOVS and SSM/I (TOVS 자료로 도출한 태풍(WALT(9407)과 FAYE(9503))에 동반된 총가강수량장)

  • 정효상
    • Korean Journal of Remote Sensing
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    • v.14 no.4
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    • pp.315-324
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    • 1998
  • The total precipitable water fields derived from HIRS(High Resolution Infrared Radiometer Sounder)and MSU(Microwave Sounding Unit) measurements of TOVS and brightness temperature of SSM/I were used to investigate the evolution of moisture fields for the Typhoon WALT(9407) which after landing in Japan it became tropical depression in Korea-Japan Strait, and FAYE(9503) which was the first tropical storm of 1995 to became a typhoon, respectively. The total precipitable water derived from TOVS observations is delineated according to the evolutions of WALT and FAYE movements because total precipitable water fields of TY WALT(9407) and FAYE9\(9503) were largely controlled by horizontal transport of water vapor over the Northwest Pacific Ocean which dominantly plays an important role in maintaining and accelerating their intensities toward Korea and Japan . These fields demonstrated that two major bands, which imply the rain bands, were locally well-organized and similar to the thick convective cloud features over Japan and the Korean peninsula while WALT and FAYE were approaching away and to. But the values of derived TOVS total precipitable water have shown the underestimate of those of SSM/I total comparatively for two typhoons.

Diagnosis with Ultrasound for Rib Fractures in the Golf (골프 운동중 발생한 늑골 골절의 초음파 진단)

  • Lim, Che-Joon;Youn, Te-Hyun;An, Ki-Yong
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.7 no.1
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    • pp.50-54
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    • 2008
  • Purpose: In most cases, the main cause of chest or back pain during playing golf is rib fractures. This kind of rib fractures can be easily overlooked in plain radiographs. The purpose of this article is to clarify the value of the ultrasound in detecting rib fractures. Materials and Methods: We compared the findings of chest-X rays (anteroposterior, left or right lateral, both oblique view) with those of the ultrasound in 56 patients between the ages of 20th & 60th who were diagnosed rib fractures. Their chief complaints were chest or back pain which developed during playing golf. The results were analyzed statistically. Results: Among 56 cases of rib fractures, 34 cases were diagnosed with initial X-rays. 51 cases were diagnosed with ultrasound. The sensitivity of radiograph and ultrasound were 60.71% & 91.07%, respectively. Dignosis was ultrasound with statical significance whereas radiography did not(p=0.0004). Conclusion: It was concluded that ultrasound is a valuable tool in the diagnosis of the rib fractures which were undetected with X-rays during playing golf.

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A Comparison of the Difference in the Golf Swing Motion According to Somatotypes (체형에 따른 골프 스윙 동작 비교)

  • Chung, Nam-Ju;Yoon, Hee-Joong;Baik, Young-Soo
    • Korean Journal of Applied Biomechanics
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    • v.12 no.2
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    • pp.33-49
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    • 2002
  • This study was intended to provide basic materials for golf coaching by somatotype by analyzing and comparing the kinematic factors found in each somatotype at the time of golf swing. For this purpose, the somatotype was divided into endomorph, mesomorph and ectomorph in reference to the weight, height and upper arm circumference of each of nine professional golfers. Each of their swing motions was videotaped with the camcorder and their swing motion was analyzed by dividing it into 8 sections. The time required for the swing motion, the displacement of the center of the human body and the rotation angle of the upper body were calculated through the three-dimensional image analysis based on the DLT(Direct Linear Transformation). Based on the findings of this study, the following conclusion was drawn: The endomorphic golfers showed the longest required golf swing time, followed by the mesomorphic golfer and then the endomorphic golfer. The displacement of left-to-right movement was largest in the mesomorphic golfers, followed by the endomorphic golfers the up-to-down displacement was upward at the time of impact and that the endomorphic and mesomorphic golfers raised the sense of stability by maintaining an almost uniform height at the time of impact. As for the rotational angle of the upper body and the rotational angle of the thigh, the upper body and the thigh took a form of rotating earlier in the ectomorphic golfers at the time of impact, who showed a somewhat different characteristics compared to the endomorphic and mesomorphic golfers. It is necessary to investigate the movement of more fundamental forces in presenting the theory related to the kinematic characteristics of this swing by somatotype. Accordingly, it is thought that it is necessary to analyze the center of pressure(COP) using the ground counterforce in the future study.

Environmental Controversy and the Role of Science - The Case of Saemangeum Reclamation Project in Korea (새만금 논쟁과 과학기술의 역할)

  • Cho Hong-Sup
    • Journal of Science and Technology Studies
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    • v.4 no.1 s.7
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    • pp.1-30
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    • 2004
  • In this paper, I have attempted to show how the environmental controversy surrounding the Saemangeurn Reclamation Project in Korea has been framed as narrow scientific debates. First of all, science, or specifically the Expert Review Pane, has played dual roles in the controversy. On the one hand, it has contributed to illuminating the future environmental impacts of reclamation, by so doing, to providing a momentum to reconsider the project. This has significant meaning that environmental concerns successfully checked the symbolic national project of developmental era through adopting a joint-investigation scheme that guaranteed participation of environmental groups on an equal footing with the government. On the other hand, by limiting the scope and participants of discussion, it fundamentally blocked the possibilities of public debates and deliberative decision-making with full considerations of the political, social, and cultural aspects of the controversy. I have shown that this is due to the realist belief shared by both the developers and the environmentalists in Korea that 'proper' science would disclose the truth. Environmental groups, in particular, were naive in evaluating the role of scientific expertise in the controversy and neglected the political role of the Expert Review Pane as a ritual. In opposition to the realist argument, I have shown through the analysis of the water quality debates concerning the future fresh water lakes that scientific 'facts' were not discovered but constructed through complex negotiations, conflicts, and compromises among related actors. The framing of the controversy as an experts' debate has resulted in the exclusion of an important actor from the discussion. Little attention has been paid throughout the controversy to the very people who have lived in the Saemangeum area for generations and will lose their livelihood all together soon. About 20,000 fishermen are living on the Saemangeum tidal flats.

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