• Title/Summary/Keyword: Impulse

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Biomechanical Analysis of gait after seven month pregnant (임산부 보행의 역학적 분석)

  • Geum, Myung-Suk;You, Sil;Kim, Young-Nan;Chung, Nam-Ju;Han, Yoon-Soo;Lee, Hun-Pyo;Yoon, Hee-Joong
    • Korean Journal of Applied Biomechanics
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    • v.12 no.1
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    • pp.15-30
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    • 2002
  • The purpose of this study was analyzed the effect of kinematical and kinetical factors of lower extremity of form change in the cause of growth an unborn child during in pregnancy. Three pregnant women were selected from pregnant 24 weeks as subjects. Each subjects were required to walk with usual walking speed. Cinematographic and GRF data were collected during walking, and the kinematical and kinetical variables were calculated using Kwon3d. Based on the results of the study, the following conclusions were drawn : 1. Step width and Step length The change of form during the period of pregnancy was not statistically found significant in the step width and the step length. 2. Angle of lower extremity 1) The change of form during the period of pregnancy was not statistically found significant in the hip angle at right heel contact, mid stance, but it was statistically found significant in the hip angle at toe off on p<.05. 2) The change of form during the period of pregnancy was not statistically found significant in the knee angle at right heel contact, mid stance, but it was statistically found significant in the knee angle at toe off on p<.05. 3) The change of form during the period of pregnancy was not statistically found significant in the ankle angle at right heel contact, mid stance, but it was statistically found significant in the ankle angle at toe off on p<.05. 3. Ground reaction force 1) The change of form during the period of pregnancy was statistically found significant in medial-lateral force(Fx) on p<.001. 2) The change of form during the period of pregnancy was not statistically found significant in post-anterior force(Fy). 3) The change of form during the period of pregnancy was statistically found significant in impulse force and minimum peak of vertical reaction force on p<.001, p<.01 but it was not statistically found significant in second maximum force.

A Study on Effective Relations between China's Cancellation of the Export Rebate of VAT tax and Chinese Steel Export to Korea. (중국의 수출 증치세 환급 취소가 중국산 철강재의 대한국 수출에 미치는 영향)

  • Lee, Seoung Taek
    • International Commerce and Information Review
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    • v.19 no.3
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    • pp.83-105
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    • 2017
  • I tried to analyze export relation of influence in Chinese H beam(common steel), Hot Rolled Steel(common steel), Plate(common steel) which could be influenced immediately by China's cancellation of the export rebate of value added tax in 2010 through the statistic methods such as cointegration, Granger causality, impulse response and variance decomposition. In the first period they mutually influenced each other in export to Korea but in the second period, this relation of influence was lessoned. Due to production expansion of Hot Rolled Steel(common steel), Plate(common steel) in Korea, the change of import trend, the market change of steel users' industries and China's expedient export of boron steel to Korea, mutual influence among these products was greatly declined. Ever since Hyundai Steel's production expansion involving blast furnace facilities, there is need for the industry to concentrate on developing new markets for its facilities' output in Korea. Therefore, Korea's steel industry desperately needs strength of de-jure standards such as unique quality standards and related certifications, efficient distribution management, as well as export promotion strategy through its global trading network to effectively address its structural supply-demand imbalances.

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Seismic Techniques for the Integrated Assessment of Structural Integrity of Concrete Runway (콘크리트 활주로 건전도상태의 종합평가를 위한 비파괴 탄성파기법)

  • Joh Sung-Ho;Kang Tae-Ho;Cho Mi-Ra;Suh Young-Chan;Kwon Soo-Ahn
    • Journal of the Korean Geotechnical Society
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    • v.21 no.4
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    • pp.51-63
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    • 2005
  • Concrete pavement may suffer from material deterioration or structural problems, which lead to surface cracks and deflection of a concrete pavement. Degraded concrete pavement, when it is still under operation, should be recovered by an urgent maintenance to avoid the discontinued service leading to the significant traffic problems and economic loss. Seismic techniques are good tools to assess the structural integrity of concrete runway. It is because seismic techniques can evaluate engineering properties nondestructively and quickly and the evaluation can be extended to subgrade. In this study, a series of numerical simulations of stress-wave propagation were performed to verify feasibility of seismic techniques as an assessment tool. Based on the results of the numerical simulation, a framework of using seismic techniques was presented fur the nondestructive integrated assessment fur structural integrity of concrete runway. And the presented framework was applied to $\bigcirc\bigcirc$ concrete runway with surface cracks, which required urgent maintenance, to identify the causes of the surface cracks. The results obtained from the structural integrity assessment were compared with the measurements of the cores collected from the same runway for verification of the presented framework.

KOSPI 200 Futures Trading Activities and Stock Market Volatility (KOSPI 200 선물의 거래활동과 현물 주식시장의 변동성)

  • Kim, Min-Ho;Nielsen, James;Oh, Hyun-Tak
    • The Korean Journal of Financial Management
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    • v.20 no.2
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    • pp.235-261
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    • 2003
  • We examine the relationship between the trading activities of Korea Stock Price Index (KOSPI) 200 futures contract and its underlying stock market volatility for about six years from May 1996 when the futures contract was introduced. The trading activities of the futures contracts are proxied by the volume and open interest, which are divided into expected and unexpected portions by using the previous data. The daily, intradilay, and overnight cash volatility is estimated by the GJR-GARCH model. We find a positive contemporaneous relationship between the intradaily stock market volatility and the unexpected futures volume while the relationship between the volatility and expected futures volume is weakly negative or non-existent. We also find that the unexpected futures volume strongly causes intradaily cash volatility. On the other hand, the overnight cash volatility causes the unexpected futures volume. The impulse responses between these variables are all positive. The result implies that during a trading time futures trading tends to increase the cash volatility while the unexpected overnight changes in cash volatility tends to increase the futures trading activities. We, however, find no association between the cash volatility and futures maturities.

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An Empirical Study of the Relationships between CO2 Emissions, Economic Growth and Openness (개방화와 경제성장에 따른 한국, 중국, 일본의 이산화탄소 배출량 비교 분석)

  • Choi, Eunho;Heshmati, Almas;Cho, Yongsung
    • Journal of Environmental Policy
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    • v.10 no.4
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    • pp.3-37
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    • 2011
  • This paper investigates the existence of the environmental Kuznets curve (EKC) for carbon dioxide $CO_2$ emissions and its causal relationships with economic growth and openness by using time series data (1971-2006) from China (an emerging market), Korea (a newly industrialized country), and Japan (a developed country). The sample countries span a whole range of development stages from industrialized to newly industrialized and emerging market economies. The environmental consequences according to openness and economic growth do not show uniform results across the countries. Depending on the national characteristics, the estimated EKC show different temporal patterns. China shows an N-shaped curve while Japan has a U-shaped curve. Such dissimilarities are also found in the relationship between $CO_2$ emissions and openness. In the case of Korea, and Japan it represents an inverted U-shaped curve while China shows a U-shaped curve. We also analyze the dynamic relationships between the variables by adopting a vector auto regression or vector error correction model. These models through the impulse response functions allow for analysis of the causal variable's influence on the dynamic response of emission variables, and it adopts a variance decomposition to explain the magnitude of the forecast error variance determined by the shocks to each of the causal variables over time. Results show evidence of large heterogeneity among the countries and variables impacts.

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The three dimensional measuring system for ELF magnetic fields with the multiturn loop-type sensors (멀티턴 루우프형 센서를 이용한 3차원 ELF 자장측정계)

  • Lee, Bok-Hee;Lee, Jeong-Gee;Kil, Gyung-Suk;Ahn, Chang-Hwan;Park, Dong-Hwa
    • Journal of Sensor Science and Technology
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    • v.5 no.2
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    • pp.29-36
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    • 1996
  • With the three dimensional magnetic field measuring system dealt with in this paper, accurate measurements and analyses of extremely low frequency(ELF) magnetic fields caused by starting and/or operating electric devices and power installations can be conducted. To obtain high performance for lower frequency and spatial components without any distortion, the measuring system is designed as three dimensionally including the multiturn loop-type magnetic field sensors, differential amplifiers and active integrators. As the results of calibration experiments, the frequency response characteristics of the measuring system range from 8[Hz] to about 53[kHz] for each direction of x, y, z axes, and the response sensitivities are 9.54, 9.21, $10.89[mV/{\mu}T]$, respectively. The actual survey experiments by using an oscillating impulse current generator confirm a reliability of the proposed measuring system. Also, through the other experiments by using small-sized induction motors, the magnetic field intensities when starting and steady-state operating mark 15.8, $8.61[{\mu}T]$ as maximum value, respectively. And those intensities decrease steeply according as the measuring distance increases.

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Study on Evaluation Method of Flow Characteristics in Steady Flow Bench(4) - Velocity Profile(2) (정상유동 장치에서 유동 특성 평가 방법에 대한 연구(4) - 유속분포(2))

  • Park, Chanjun;Sung, Jaeyong;Ohm, Inyong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.2
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    • pp.242-254
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    • 2016
  • This paper is the forth investigation on the evaluation methods of flow characteristics in a steady flow bench. In the previous works, it was concluded that the assumption of the solid rotation might cause serious problems and both of the eccentricity and the velocity profile distort the flow characteristics when using the ISM at 1.75B plane. Also particle image velocimetry (PIV) measurement at this position showed that the real velocity profile was far from the assumption of ISM evaluation. In this paper, the planar velocity profiles were measure from 1.75B to 6.00B position by PIV and the characteristics were examined according to the valve angles and lifts for further investigations about the effect of the position on the velocity profile. The results show that $26^{\circ}$ valve angle is always an unique exceptional case in all aspects. If the valve angle is $21^{\circ}$ and below, the planar velocity profiles according to the lift and the position are similar to each other, however, the tangential velocity curves along with the radial direction have common tendencies up to $16^{\circ}$ angle. Also the well arranged swirl behaviors are generally observed at the position above 3.00B and the velocity contour lines come closer to the concentric circle as the valve lift increases. In addition, the gradient of tangential velocity along with the radial direction from the swirl center becomes stable and constant as the position goes downstream. Concurrently the velocity gradient is larger to the eccentric direction of the center. In the meantime the tangential velocity curves along with the radial direction are irregular and various at 1.75B, however, they become regular and reach higher level as the evaluation position goes downstream. At this time the curves of 4.50B are the best fitted to the ideal one. On the other hand in an exceptional case, $26^{\circ}$, the velocity contours are very complicated over 6mm valve lift regardless the position and the gradient increases to the opposite direction of the eccentric center. Also, 6.00B is a best fitting position in the geometrical cylinder center base. With respect to the swirl center, the distribution range of centers for 1.75B is different to that for the other positions and the eccentricities of this plane are larger regardless the valve angle. After 1.75B, there is no certain tendency in the center position change according to the valve angle and lift. Additionally, the eccentricities are not sufficiently small to neglecting the effect on ISM measurement.

Performance Evaluation of 1 N Class HAN/Methanol Propellant Thruster (HAN/메탄올 추진제를 사용하는 1 N급 추력기 성능 평가)

  • Lee, Jeongsub;Huh, Jeongmoo;Cho, Sungjune;Kim, Suhyun;Park, Sungjun;Kim, Sukyum;Kwon, Sejin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.4
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    • pp.299-304
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    • 2013
  • The HAN which is an ionic liquid is a non-toxic monopropellant with high storability, and its specific impulse can be increased by blending methanol, thereby it can substitute the hydrazine. The HAN was synthesized by acid-base reaction of hydroxylamine and nitric acid, and the blending ratio of HAN and methanol is 8.2:1. The iridium catalyst was used to decompose the HAN, and 1 N class thruster with shower head type injector having one orifice was used to evaluate the HAN/Methanol propellant. The thermal stability of distributor was increased by using ceramic material to endure the high temperature of product gas. The preheating temperature of catalyst should be $400^{\circ}C$ at least for the complete decomposition. The feeding pressure should be increased to increase the $C^*$ efficiency, thereby the decomposition performance was decreased upstream catalyst, and the performance of thruster was decreased. The fine metal mesh was inserted after the injector to improve the atomization of propellant, thereby it can settle the performance decrease problem. The phenomenon of performance decrease was remarkably improved owing to the insertion of fine metal mesh.

A Study on the Responsibility Judgment and Mental Disorder of Criminal Psychology (책임능력판단에 관한 범죄심리학적 이론과 정신장애 항변 연구)

  • Rim, Sang-Gon
    • Korean Security Journal
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    • no.10
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    • pp.293-322
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    • 2005
  • The culpability of a person, as determined by due process of law, for any of his actions that are defined as criminal. Determination of such responsibility is a legal function, not a psychiatric one, although a psychiatrist may be called upon to present evidence to the court in order to aid the judge or jury in reaching a decision as to responsibility. Determination of responsibility varies with the laws of the state in which the accused is being tried, but in general all states base their laws on three famous judicial decisions concerning criminal responsibility. 1. the M'Naghten(McNaughton) rule(a. to establish such a defense the accused, at the time the act was committed, must be shown to have been laboring under such defect of reason as not to know the nature and quality of the act he was doing, b. if he did know it, he did or know that what he was doing was wrong). 2. the irresistible impulse test. 3. the Durham decision. Under the Durham test, however, the psychiatrist may give any relevant testmony concerning the mental illness at issue. The psychological and behavioral appearance of a person, in clinical psychiatry this term is commonly used to refer to the results of the mental examination of a patient. The written report of the mental status usually contains specific references to the following areas: I. Attitude and General Behavior (1)General health and appearance. (2)General habits of dress. (3)Personal habits. (4)General mood. (5)Use of leisure time. (6)Degree of sociability. (7)Speech. II. Attitude and Behavior during interview (1)Co-operativeness. (2)Poise. (3)Facial expression. (4)Motor activity. (5)Mental activity. (6)Emotional reactions. (7)Trend of thought. III. Sensorium, mental grasp, and capacity (1)Orientation. (2)Memory and retention. (3)Estimate of intelligence. (4)Abstraction ability. (5)Tests of absurdity, interpretation of proverbs. (6)Judgment.

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Comparison of Antinociceptive Effect of Korean and American Bee Venoms on Pain in Rodent Models (설치동물에서 통증에 대한 한국산 및 미국산 봉독의 진통효과의 비교)

  • Kim, Jong-Min;Han, Tae-Sung;Kang, Seong-Soo;Kim, Gon-Hyung;Choi, Seok-Hwa
    • Journal of Veterinary Clinics
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    • v.27 no.6
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    • pp.663-667
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    • 2010
  • Experiments were undertaken to assess the antinociceptive effect of bee venom (BV) in rodent animal models. Comparison of antinociceptive efficacy between Korean BV and commercially available American BV was the primary interest of the study. Korean BV was collected using BV collector devices in which an electrical impulse is used to stimulate the worker bee (Apis mellfera L.) to sting and release venom. After collection, whole BV was evaporated until dry using the BV collector. Commercially available dried American BV was purchased from Sigma Company in USA. Korean and American sourced BVs were diluted and amounts of 6 mg/kg body weight (BW), 0.6 mg/kg BW and 0.06 mg/kg BW were tested. BV was subcutaneously injected to produce an antinociceptive effect and the antinociceptive efficacy was evaluated using a writhing test in mice and a formalin test in rats. The antinociceptive effects of the two BVs tested were similar in mice for visceral pain and showed a dose-dependent response. The antinociceptive effect of Korean BV was not significantly different compare to American BV. These results suggest that Korean BV may be used to achieve an antinociceptive effect for use in medical therapies.