• Title/Summary/Keyword: 하강운동

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Effect of Whole Body Vibration Training in Drop Landing Jump (전신진동운동이 드랍랜딩점프 동작에 미치는 영향)

  • Hong, Su-Yeon;Jang, Young-Kwan;Kim, Jin-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.423-429
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    • 2018
  • Objective: This study was conducted to investigate the effects of WBVE on biomechanical factor analysis of drop landing jumps before and after a four week training program. Methods: Participants were divided into two group: VEG (n=5, age: $25.7{\pm}2.3yrs$, height: $170{\pm}7.6cm$, weight: $69.3{\pm}8.3kg$) and OEG (n=5, age: $24.6{\pm}3.4yrs$, height: $164{\pm}4.9cm$, weight: $58.8{\pm}9.2kg$). Ten infrared cameras (Vicon, UK) with a sampling rate of 100 Hz were used in two GRF measurement systems (AMTI, USA). Results: The variability of the center of mass was largest at the falling phase, and there was a great risk of injury when landing after the jump. Second, the jumping heights of the VEG (vibration exercise group) were higher than those of the OEG (only exercise group), regardless of training period. Third, there were significant differences in the hip joint P1 (flexion) and knee joint P2 (extension) between the exercise groups after 4 weeks of training. However, there were no significant differences among training periods or phases. Conclusion: regardless of training periods, the VEG showed increased jump height compared with the OEG, but the consistency between the jump height and the lower joint power could not be determined.

A Kinematic Comparison of Start Motion Between the Swimming and Fin-Swimming (수영과 핀수영 스타트 동작의 운동학적 비교)

  • Kim, Seung-Kwon
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.97-105
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    • 2008
  • The kinematic variables for swimming and fin-swimming start motions were analyzed and compared using 3-dimensional cinematography. For the swimming start, the arm segment moved towards the upper rear and trunk towards the upper front followed by a descent towards the lower front, while the fin-swimming start motion showed movement towards the lower front for all segments. The total body center of gravity for the swimming start showed horizontal movement far to the front followed by a rapid descent while the fin-swimming start showed close movement towards the lower front in a short period of time. Upon entering the water, the center of gravity for swimming showed high vertical velocities while fin swimming had high horizontal velocities. For both swimming and fin swimming, the upper extremity velocity had more influence on the total center of gravity velocity than the lower extremities. Flexion of the hip joint was observed before the jump for the fin swimming start while the swimming start showed two flexions in mid-air succeeding the jump. The flexion and extension movements at the knee joint during the fin-swimming start motion were shown to be larger and more rapid than those of fin-swimming.

The Politics of Scale: The Social and Political Construction of Geographical Scale in Korean Housing Politics (스케일의 정치: 한국 주택 정치에서의 지리적 스케일의 사회적.정치적 구성)

  • Ryu, Yeon-Taek
    • Journal of the Korean Geographical Society
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    • v.42 no.5
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    • pp.691-709
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    • 2007
  • This paper investigates the social and political construction of geographical scale in conjunction with Korean housing politics. Recently, attention has been drawn to the issue of the social and political construction of geographical scale. Spatial scales have increasingly been regarded as socially constructed and politically contested rather than ontologically pregiven or fixed. The scale literature has paid attention to how different spatial scales can be used or articulated in social movements, with an emphasis on 'up-scaling' and 'scales of activism' rather than 'down-scaling' and 'scales of regulation.' Furthermore, the scale literature has focused on the aspect of empowerment. However, it is worthwhile to examine how scale-especially 'down-scaling' and 'scales of regulation'-can be used not only for marginalizing or excluding unprivileged social groups, but also for controlling the (re)production of space, including housing space. Under a regulatory regime, the Korean central government gained more control over the (re)production of housing space at geographical multi-scales by means of 'jumping scales,' specifically 'down-scaling.' The Korean central government has increasingly obtained the capacity to 'jump scales' by using not only multiscalar strategies for housing developments, but also taking advantage of various scales of institutional networking among the central and local governments, quasi-governmental institutions, and Chaebols, across the state. Traditionally, scale has been regarded as an analytical spatial unit or category. However, scale can be seen as means of inclusion(and exclusion) and legitimation. Choosing institutions to include or exclude cannot be separated from the choices and range of spatial scale, and is closely connected to 'scale spatiality of politics.' Facilitating different forms of 'scales of regulation,' the Korean central government included Chaebols and upper- and middle-income groups for the legitimization of housing projects, but excluded local-scale grassroots organizations and unprivileged social groups as decision-makers.

Review on the Relative Sea-level Changes in the Yellow Sea during the Late Holocene (한반도 서해안의 후기 홀로세 해수면 변동 곡선에 대한 검토)

  • Choi, Sung-Ja
    • Economic and Environmental Geology
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    • v.51 no.5
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    • pp.463-471
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    • 2018
  • In this paper, we review previous studies on the relative sea-level changes in the Yellow Sea during the Holocene to comprehensive understand the various research results. Currently, it is reported two theories : 1) the Holocene sea-level has never been higher than the present-day level; and 2) sea-level have reached highstand during mid-Holocene, followed by slow lowering to that of the present. The first theory yields a curve that is similar to a climate-change-related eustatic sea-level curve. However, in reality, most of the relative sea-level fluctuation resulted from land uplift or subsidence. The second theory yields a curve that is fairly coincident with a relative sea-level curve indicative of continental margins being located away from the ice sheets(i.e., far-field), and is considered as an effect of GIA(Glacio Isostatic Adjustment) and gravitational attraction. Based on detailed review of previous researches, we realized that they sourced the same papers, but obtained different results because they selectively chose and added the data. The data used to derive the second theory pertain to the northern Gunsan region, which is located within the western area of the Chugaryeong fault. Thus, we believe that the sea-level curve for the second theory is only representative of the area north of Gunsan, which is subject to GIA and tectonic deformation. Although the relative sea-level curve for the west coastal area is comparable to that for the far-field continental margin region, it is necessary to evaluate local tectonic activities as suggested by active seismicity in the west coastal area and the more than 400 faults currently existing in on the Korean Peninsula.

Effects of a Tongue Self-Resistance Exercise on the Swallowing Function of Patients With Stroke: Case Report (자발적 혀 저항 운동이 뇌졸중 환자의 삼킴기능에 미치는 효과: 사례연구)

  • Nam, Kyung-Wan
    • Therapeutic Science for Rehabilitation
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    • v.7 no.4
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    • pp.43-55
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    • 2018
  • Objective: This study aims to discover how tongue self-resistance exercise affects the swallowing function of patients with stroke. Method: The subjects of this study were two patients who were treated at the Y hospital in Gyeonggido. Data were gathered by VFSS regarding the degree of swallowing disability and oral intake before and after intervention. This study analyzed case studies of two patients. One patient's intervention was applied in September 2012 for three weeks. The other's intervention was applied in February 2014 for three weeks. At the first session, the VFSS examination was administered. Then, intervention began after the patients gave their consent for participation. Each session was practiced 10 times per set, but one session had 3 sets. Intervention frequency consisted of five sessions per week, and it was conducted for three weeks. Tongue self-resistance exercise included tongue protrusion, tongue lateralization, and tongue elevation on the hard palate. Results: The first tongue self-resistance exercise had a positive effect on swallowing function because of the decrease in VFS score. The second tongue self-resistance exercise showed improved oral intake based on FOIS scores. Conclusion: This study's results suggest that there are many benefits of tongue self-resistance exercise on the swallowing function when it is applied to patients with stroke.

An Experimental Study for Secondary Currents in Open-channel Flows over Submerged Vegetation (침수식생 개수로의 이차흐름에 대한 실험연구)

  • Yang, Won-Jun;Choi, Sung-Uk;Choi, Byung-Woong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.400-404
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    • 2009
  • 본 연구에서는 곧은 식생과 유연한 식생 및 다양한 수심비를 갖는 개수로 흐름 조건에 대한 수리실험을 실시하였다. 레이저 도플러 유속계를 이용하여 수로 전체 단면의 유속을 측정함으로써, 이차흐름이 평균유속 및 난류량에 미치는 영향을 분석할 수 있도록 하였다. 평균유속의 경우, 수치모의결과와 동일하게 측벽근처에서 최대 유속이 발생하였다. 유속측정자료를 이용하여 침수식생 개수로 흐름의 벡터도를 살펴본 결과, 침수식생 개수로의 경우 일반 개수로 흐름과는 달리 바닥 와 (bottom vortex)가 측벽 근처에서 매우 활발한 것으로 나타났으며, 이로 인해 수로 중앙의 높은 운동량을 가진 유체가 측벽방향으로 이동하고 있음을 확인하였다. 또한 측벽에서 이차흐름으로 인해 발생하는 강한 하강류가 레이놀즈응력 및 난류 강도의 수직방향 분포 형태에 영향을 미치는 것을 확인하였다.

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Effect of Glycerol Concentration, Freezing Rate and Thawing Rate on Semen Characteristics in PoongSan-dog (풍산개 정자의 동결보존에 있어서 Glycerol 농도, 동결 및 융해속도가 정자성상에 미치는 영향)

  • Ji, D.Y.;Yoon, T.C.;Rho, J.R.;Cho, S.R.;Kim, C.K.;Pang, M.G.;Kim, Bo-Sook
    • Journal of Animal Science and Technology
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    • v.49 no.5
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    • pp.585-592
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    • 2007
  • This research was carried out in order to establish the production technique for Poong-san dog’s frozen semen, by examining the semen characteristic and the volume of glycerol added to the dilution solution, thawing temperature and sperm motility and viability as well as the motility using CASA according to time variation. Average semen volume was 5.9ml, sperm concentration 116.3×106 sperm/ml, total sperm number 789.3×106 sperm, motility 88.7±1.7% and viability 87.6±7.8%. When it was cryopreservation and thawed at different glycerol concentrated extender, it showed 52.7% motility and 57.7±10.3% viability at 7% glycerol, compared to other treatments. For semen cryogeny, at conditions of 5, 7cm and a height of 10cm for pre-cryogeny and maintaining the semen at 7cm from the surface of liquid nitrogen resulted in profitable motility and viability.

Characteristics of Atmospheric Circulation and Heat Source related to Winter Cold Surge in Korea (한반도 겨울철 한파와 관련된 대기 순환과 열원의 특성)

  • Kim Maeng-Ki;Shin Sung-Chul;Lee Woo-Seop
    • Journal of the Korean earth science society
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    • v.26 no.6
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    • pp.560-572
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    • 2005
  • This study investigates the characteristics of atmospheric circulation and the heat source $(Q_1)$ related to the winter cold surge in Korea from 1979 to 1999. The occurrence frequency of cold surge is about one event per year and $60\%$ of the total events occurred during the former period, before 1989. During the cold surge, the pressure pattern shows more dominant east-west dipole circulation pattern in the lower troposphere and the effect of upper level trough is stronger than normal cases. Temperature falling pattern over Korea shows that the pattern opposite to the temperature structure over Lake Baikal and temperature change has opposite signs between the low-middle level and upper level, with the boundary at 400 hPa. The analysis of heat source shows that atmospheric cooling by cold advection during the cold surge is balanced by adiabatic warming due to downward motion, indicating that the movement path of cold core is associated with that of heat sink. Therefore, the movement mechanism of the heat source and sink should be well known for understanding the maintenance mechanism of cold surge and predicting cold surges.

Numerical Analysis of Flowfield around Multicopter for the Analysis of Air Data Sensor Installation (대기자료센서 장착위치 분석을 위한 멀티콥터 주변 유동장 수치해석)

  • Park, Young Min;Lee, Chang Ho;Lee, Yung Gyo
    • Journal of Aerospace System Engineering
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    • v.11 no.5
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    • pp.20-27
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    • 2017
  • The present paper describes the flow analysis of the flows around the multicopter for the selection of optimal position of air data sensor. For the flow analysis, the commercial fluid dynamics solver, STAR-CCM+ was used with polygon mesh and k-w SST turbulence modeling options. For the simulation of each rotating 4 propellers, unstructured overset mesh method was used. Hovering, forward flight, ascending and descending flight conditions are selected for the analysis and airspeed and flow angle errors were investigated using the CFD results. Through the flow field analysis, sensor location above one propeller diameter distance from the propeller rotating plane showed airspeed error less than 1m/s within the typical flight conditions of multicopter except descending.

Design of lift-down kitchen cabinet for elderly and disabled (고령자 및 장애인을 위한 승강형 주방 상부장 설계)

  • Kibum Shim;Hoon Shim;Geon-Hyeok Lim;Jiwon Jang;Sang-Hyun Kim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.1
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    • pp.465-470
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    • 2024
  • Kitchen cabinets are widely used for their spacious storage and efficient use of space, but their high installed location makes it difficult for the elderly and disabled to access. Therefore, in this paper, we propose a new height-adjustable kitchen cabinet that can be used more easily and safely. The lift-down range of cabinet was set considering the installation location of cabinet for efficient use of kitchen space and the maximum height accessible to the elderly and disabled, and the link geometry and driving method of the complex link mechanism were determined through the mechanism design procedure to ensure that the selected floor come down safely along the optimal descend path. In addition, the appropriate motor and control algorithm were added to allow the user to descend to the desired height with a simple button operation. It was confirmed through actual production that the proposed linkage mechanism performs the desired lift-down motion.