• Title/Summary/Keyword: Gravity Effect

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The Factors Affecting Kyrgyzstan's Bilateral Trade: A Gravity-model Approach

  • Allayarov, Piratdin;Mehmed, Bahtiyar;Arefin, Sazzadul;Nurmatov, Norbek
    • The Journal of Asian Finance, Economics and Business
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    • v.5 no.4
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    • pp.95-100
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    • 2018
  • The study investigates the factors that affect Kyrgyzstan's bilateral trade flows with its main trading partners and attempts to predict trade potential for Kyrgyzstan. Using panel data, the gravity model is applied to estimate Kyrgyzstan's trade from 2000 to 2016 for its 35 main trading partners. The coefficients derived from the gravity-model estimation are then used to predict trade potential for Kyrgyzstan. Results proved to be successful and explained 63% of the fluctuations in Kyrgyzstan's trade. According to the results, Kyrgyzstan's and its partners' GDP have a positive effect on trade, while distance and partners' population prove to have a negative effect. Predicted trade potential reveals that neighboring countries (China, Kazakhstan, Uzbekistan, and Tajikistan) and Russia still have a significant trade potential. Kyrgyzstan, being a less developed economy, even by Central Asia standards, can only achieve its goals of reducing poverty and becoming more developed by increasing its overall trade with the rest of the world. Therefore, it is essential to study the main determinants of Kyrgyzstan's bilateral trade. In this way, we can help policy makers formulate policies to expand Kyrgyzstan's trade. This study is the first attempt to apply to the gravity model to Kyrgyzstan in an attempt to predict trade potential.

Effect of Accelerated Rehabilitation with Anti-Gravity Treadmill Exercise on Ankle Joint Function After Surgery of Modified Brostrom Operation in Chronic Ankle Instability Patients (변형된 Brostrom 수술 후, Anti-gravity treadmill 가속재활운동이 만성발목불안정성 환자의 발목기능 회복에 미치는 영향)

  • Choi, In-Hyuk;Lee, Jang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.228-235
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    • 2019
  • The purpose of this study was to investigate the effect of 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise on VAS, ROM, isokinetic myofunction, and dynamic stability after surgery of modified brostrom operation in chronic ankle instability patients. The subjects of this study were 12 chronic ankle instability patients who underwent modified Brostrom operation(MBO) by the same doctor. 6 weeks' accelerated rehabilitation program is scheduled to perform for 60min, everyday, and also anti-gravity program performed for 15~30min, everyday. The visual analog scale(VSA) and significantly decreased(p<.001) and ROM in all of dorsal flexion, plantar flexion, inversion and eversion significantly increased(p<.05) after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise. Both inversion and eversion peak torque at $60^{\circ}/sec$(p<.001, p<.01) and at $180^{\circ}/sec$(p<.001) significantly increased after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise respectively. In muscle defect, although inversion(p<.01) and eversion(p<.001) at $60^{\circ}/sec$ and inversion(p<.01) at $180^{\circ}/sec$ significantly decreased, eversion at $180^{\circ}/sec$ tended to decrease but did not change significantly after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise. The dynamic stability significantly increased after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise(p<.001). These results suggest that 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise has positive effect of VAS, ROM, isokinetic myofunction, and dynamic stability after surgery of modified brostrom operation in chronic ankle instability patients. Therefore, we consider that the accelerated rehabilitation with anti-gravity treadmill exercise, which is safely and fast method, has effect on more faster recovery of ankle stability, play ground and normal daily activities.

Effects of Load Center of Gravity and Feet Positions on Peak EMG Amplitude at Low Back Muscles While Lifting Heavy Materials (중량물 들기 작업시 물체 무게중심 및 발의 위치가 허리 근육의 최대 EMG 진폭에 미치는 영향)

  • Kim, Sun-Uk;Han, Seung Jo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.22 no.3
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    • pp.257-264
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    • 2012
  • Objectives: This study's aims were to evaluate the effects of load center of gravity within an object lifted and feet placements on peak EMG amplitude acting on bilateral low back muscle groups, and to suggest adequate foot strategies with an aim to reducing low back pain incidence while lifting asymmetric load. Methods: The hypotheses that asymmetric load imposes more peak EMG amplitude on low back muscles contralateral to load center of gravity than symmetric load and maximum peak EMG amplitude out of bilateral ones can be relieved by locating one foot close to load center of gravity in front of the other were established based on biomechanics including safety margin model and previous researches. 11 male subjects were required to lift symmetrically a 15.8kg object during 2sec according to each conditions; symmetric load-parallel feet (SP), asymmetric load-parallel feet (AP), asymmetric load-one foot contralateral to load center of gravity in front of the other (AL), and asymmetric load-one foot ipsilateral to load center of gravity in front of the other (AR). Bilateral longissimus, iliocostalis, and multifidus on right and left low back area were selected as target muscles, and asymmetric load had load center of gravity 10cm deviated to the right from the center in the frontal plane. Results: Greater peak EMG amplitude in left muscle group than in right one was observed due to the effect of load center of gravity, and mean peak EMG amplitudes on both sides was not affected by load center of gravity because of EMG balancing effect. However, the difference of peak EMG amplitudes between both sides was significantly affected by it. Maximum peak EMG amplitude out of both sides and the difference of peak EMG amplitude between both sides could be reduced with keeping one foot ipsilateral to load center of gravity in front of the other while lifting asymmetric load. Conclusions: It was likely that asymmetric load lead to the elevated incidence of low back pain in comparison with symmetric load based on maximum peak EMG amplitude occurrence and greater imbalanced peak EMG amplitude between both sides. Changing feet positions according to the location of load center of gravity was suggested as one intervention able to reduce the low back pain incidence.

Effect of Sugar Particle Size and Level on Cookie Spread (설탕의 粒子 크기와 使用量이 쿠키의 展性이 미치는 影響)

  • Koh, Won-Bang;Noh, Wan-Seob
    • Journal of the East Asian Society of Dietary Life
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    • v.7 no.2
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    • pp.159-165
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    • 1997
  • The primary objective of this study was to learn the effect of various sugar particle size and level on cookie spread, The effect of sugar particle size and level on sugarsnap cookie spread was studied. Three different particle sized sugars; powered sugar, granulated sugar and sanding sugar, were used for the cookie test baking with five different sugar levels; 30, 45, 60, 75 and 90% based on the weight of flour. In mixing process, 5 minutes of creaming time was used for cream making and then the specific gravity of cream was measured on the basis of each different sugar particle size and level. In the result, the specific gravity of cream was influenced by sugar particle size and sugar level. However, the specific gravity of cream had no influence on cookie dough specific gravity. Cookie spread was influenced by sugar particle size and sugar level. Greater cookie spread was obtained by decreasing sugar particle size and increasing sugar level resulted in increased spread. Therefore, selection of suitable sugar particle size and its use level can be factors in controlling spread and imparting desired packaging characteristics.

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Does Urbanization Affect Bilateral Trade? (양국의 도시화가 무역에 미치는 영향: 중력 모형의 활용)

  • EunJung Lim;Sunghee Jun
    • Korea Trade Review
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    • v.45 no.3
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    • pp.119-132
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    • 2020
  • In this paper we explore the two analyses to know the urbanization effect on trade. First, the granger causality test to examine the relationship between trade and urbanization. The Granger causality test is a statistical hypothesis test for determining whether one time series is useful for forecasting another. The results indicated that the existence of a bidirectional causality running from trade to urbanization when six lags were applied. When eight lags were applied, we found unidirectional causality running from urbanization to trade. Second, gravity models were used to investigate the urbanization effect on trade. The production cost and specification are affected by the economies of scale, and the economies of scale increased as the greater geographically agglomeration. However, the gravity model to explain the bilateral trade flows ignores the urbanization variables. Therefore we added the urbanization variable represented as the geographically agglomeration into gravity model. The results show that the degree of urbanization of both countries has statistically positive effect on trade (export and import) and the bigger coefficients of trade partner's urbanization. The reason is that the trade share of industrial supplies, intermediate goods and capital goods is much higher than finished consumer goods. The urbanization is more important the improved the efficiency of production than demand market.

Numerical Analysis of Artificial Supercavitation under the Gravity Effect (중력 효과를 받는 인공 초공동에 대한 수치해석)

  • Kim, Ji-Hye;Jeong, So-Won;Ahn, Byoung-Kwon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.5
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    • pp.665-672
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    • 2017
  • Supercavitation can be generated at relatively lower speeds by injecting compressed air behind the cavitator. As a result, an artificially created supercavity is deformed and its tail tends to rise due to gravitational effects. However, practical prediction of the artificial supercavity currently depends on empirical results. In this study, a mathematical model for the artificial supercavity under the gravity effect is proposed. Based on a boundary element method, geometric characteristics of the supercavity at different flow conditions are examined. The results were compared with an existing empirical formula and also experimental observations carried out at a cavitation tunnel of the Chungnam National University.

Dynamic Stability Analysis of a Rotating Blade Considering Gravity Effect (중력의 영향이 고려된 회전 블레이드의 동적 안정성 해석)

  • Jung, Kang-Il;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.11
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    • pp.1052-1057
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    • 2010
  • Dynamic stability of rotating blade considering gravity effect is investigated in this paper. Equations of motion for the beam is derived by employing hybrid deformation variable method and transformed into dimensionless form. The present modeling method is verified by RecurDyn. Stability diagrams are presented to show the influence of the configuration of the beam and angular velocity on the dynamic stability by applying Floquet's theory. Since the natural frequencies are varied when the blade has rotating motion, it is found that relatively large unstable regions exist approximately 1.1 times as high as the first bending natural frequency and half of the sum of first and second bending natural frequency.

Nonlinear behavior of concrete gravity dams and effect of input spatially variation

  • Mirzabozorg, H.;Kianoush, R.;Varmazyari, M.
    • Structural Engineering and Mechanics
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    • v.35 no.3
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    • pp.365-377
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    • 2010
  • In the present article, effect of non-uniform excitation due to spatially variation of seismic input on nonlinear response of concrete gravity dams is considered. The reservoir is assumed compressible. Isotropic damage mechanics approach is used to model static and dynamic nonlinear behavior of mass concrete in 2D space. The validity of utilized nonlinear model is considered using available theoretical results under static and dynamic conditions. The tallest monolith of Pine Flat dam is selected as a case study. Two cases are analyzed for considering the effect of limited wave propagation velocity on seismic behavior of the dam-reservoir system in which travelling velocities are chosen as 2000 m/s and infinity. It is found that tensile damage in neck and toe regions and also, in the vicinity of the base increase when the system is excited non-uniformly.

Analysis of the 500M Short track speed skating starting motion according to the center of gravity position ratio (인체 무게 중심 분할에 따른 500m 숏트트랙 스피드 스케이팅 출발 기술 분석)

  • Back, Jin-Ho;Chung, Nam-Ju;Han, Ki-Hoon;Lee, Yong-Goo;Yoon, Dong-Seob;Lee, Yong-Sik
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.199-215
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    • 2003
  • The purpose of this study was to attempt new starting motion and supply present starting motion in the 500M short track speed skating according to the center of gravity position. The center of gravity position ratio was divided starting motion into five(type A : front 80%-back 20%, type B front 70%-back 30%, type C : front 50%-back 50%, type D : front 30%-back 70%, type E : front 20%-back 80%). The three dimension motion analysis with DLT(direct linear transformation) method was executed using two video cameras. The following conclusion was that It was appear that reaction and execution time in starting motion was the most short in type B. It was characteristic that step of skaters was shorten and center of gravity position ratio was not effect to change of the step in each event. It was appear that the displacement of type D and type E were longer than that type A and type B during the starting motion. It was appear that skill types of center of gravity position ratio to the front were lower than that to the back and contract a posture. Observing the above, it was conclusion that skill type B of center of gravity position ratio to the tent was more effect than that to the back. But it is important that these skill type was most used to the competition and estimate the result.

Observation of gravity changes associated with variations of ground water table (지하수 수위변동에 따른 중력 변화 양상)

  • Eom, Joo-Young;Seo, Ki-Weon;Koo, Min-Ho;Kwon, Byung-Doo
    • 한국지구물리탐사학회:학술대회논문집
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    • 2009.10a
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    • pp.119-123
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    • 2009
  • Gravity changes due to variations of groundwater level were measured at a ground water monitoring well, which is located at Kum-san, Korea, from November 2008 to September 2009 using Portable Earth Tide (PET) gravimeter. Groundwater level was monitored simultaneously with gravity observations. To extract gravity information from groundwater, we reduced gravity effect from atmospheric surface pressure, earth tides and its loading effect, polar motion and meter drift. In addition, in June 4, 2009, there was a pumping test at he observation well, and groundwater level and gravity variations were observed together successfully. Observation of gravity along with groundwater level is potentially useful for monitoring of aquifer water mass balance and water resources.

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