• Title/Summary/Keyword: Ground Condition

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The Research for Using Method of GRF (Ground Reaction Force) on Rotational Movement in Arabesque (아라베스크 회전동작 시 지면반력 활용방법에 관한 연구)

  • Gwon, An-Suk;Lee, Geon-Beom
    • Korean Journal of Applied Biomechanics
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    • v.15 no.2
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    • pp.1-10
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    • 2005
  • G. B. LEE, A. S. GWON, The Research for Using methodof GRF (Ground Reaction Force) on Rotational Movement in Arabesque. Korean Journal of Sport Biomechanics, Vol. 15, No. 2, pp.1-10, 2005. As, in relation to all movements of a human being, the movements such as mutually walking, running, rotating, and jumping are attained endlessly through the ground amid the interaction with the ground, in terms of the harmonious movement of the upper limbs and the lower limbs, related to the basic movement in ballet, the type of a movement depends on the size and direction of the force that presses down the ground (Fz, Fx, Fy) amid the interaction with the ground. Therefore, aiming to correctly and efficiently perform a rotational movement in Arabesque, this study analyzed factors of the force manifestation through GRF (Ground Reaction Force), by dividing into preparing, stepping, standing, rotating, and finishing stages (events (1) ${\sim}$ (5)), targeting the subjects of 4 elite female students who majored in ballet. 1. At the No.5 position of the preparing stage, It is necessary that support the ground with left and right foot balance, 2. As the stepping stage is the phase ranging from the event (2), in which a plie movement of bending a knee is started, to the event (3) of stretching a knee, Rebunding motion is not good, and One have a position with ankle and knee flextion condition in order to stretch strengthly in event (3) position 3. At the event (1) position, It is necessary that exert the Fz reaction force at the event (3) position. Because large stretch force help to have a toe on position easily and show a active motion 4. In order to have a stand and rotation motion smoothly, One need a muscle strength training for ankle extension, knee extension, control horizental force

Multi-axial Vibration Testing Methodology of Vehicle Component (자동차 부품에 대한 다축 진동내구 시험방법)

  • Kim, Chan-Jung;Bae, Chul-Yong;Lee, Dong-Won;Kwon, Seong-Jin;Lee, Bong-Hyun;Na, Byung-Chul
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.297-302
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    • 2007
  • Vibrating test of vehicle component can be possible in lab-based simulators instead of field testing owing to the development of technology in control algorithm as well as computational process. Currently, Multi-Axial Simulation Table(MAST) is recommended as a vibrating equipment, which excites a target component for 3-directional translation and rotation motion simultaneously and hence, vibrational condition can be fully approximated to that of real road test. But, the vibration-free performance of target component is not guaranteed with MAST system, which is only simulator subjective to the operator. Rather, the reliability of multi-axial vibration test is dependent on the quality of input profile which should cover the required severity of vibrating condition on target component. In this paper, multi-axial vibration testing methodology of vehicle component is presented here, from data acquisition of vehicle accelerations to the obtaining the input profile of MAST using severe data at proving ground. To compare the severity of vibration condition, between real road test and proving ground one, energy principle of equivalent damage is proposed to calculate energy matrices of acceleration data and then, it is determined the optimal combination of special events on proving ground which is equivalent to real road test at the aspects of vibration fatigue using sequential searching optimal algorithm. To explain the vibration methodology clearly, seat and door component of vehicle are selected as a example.

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A Case Study on Reinforcement of Ground and Foundation against Subsidence in Abandoned Mining Area (폐광지역 침하방지를 위한 지반 및 구조물기초 보강)

  • Kim, Do-Hyung;Choi, Chang-Rim;Kim, Dong-Hyun;Lee, Du-Hwa;Lee, Baek-Song;Je, Hae-Chan
    • Tunnel and Underground Space
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    • v.17 no.4
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    • pp.255-265
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    • 2007
  • As the mechanism and effect range of subsidence are altered according to the various conditions (the ground condition, the earth pressure, the geometric condition of underground cavity and the structure load), the analysis and prediction of subsidence in abandoned mining area are very difficult. Also, as the geological characteristics and the mining methods are differed in each mines, the application of the pre-existing reinforcements without improvement has a lot of difficulties and limits. In this study, the various underground investigation such as long-depth core drilling, seismic tomography and BIPS (borehole image processing system) were performed, the distribution of underground cavity and coal seam and rock relaxation condition were analyzed. And we predicted the type of subsidence and estimated the subsidence by theories of mining subsidence. With these results, we analyzed the mechanism of subsidence occurrence in the research object area. Finally, we improved existing methods which were applied to the abandoned mining area and also we established the rational reinforcement for the ground and structure foundation against each subsidence cause.

A Study on the Hypersonic Air-breathing Engine Ground Test Facility Composition and Characteristics (극초음속 공기흡입식 추진기관 지상 시험설비의 구성 및 특성에 관한 연구)

  • Lee, Yang-Ji;Kang, Sang-Hun;Yang, Soo-Seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.6
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    • pp.81-90
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    • 2015
  • In order to know the characteristics of the hypersonic air-breahting engine, high altitude and Mach number ground test is necessary. Therefore, high pressure and high temperature condition should be simulated to do ground test of the hypersonic air-breathing engine. In this paper, the hypersonic air-breathing engine ground test facility of the Korea Aerospace Research Institute was introduced and the composition and characteristics were described.

Development of Back Analysis Program for Total Management Using Observational Method of Earth Retaining Structures under Ground Excavation (지반굴착 흙막이공의 정보화시공 종합관리를 위한 역해석 프로그램 개발)

  • 오정환;조철현;김성재;백영식
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.10c
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    • pp.103-122
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    • 2001
  • For prediction of ground movement per the excavation step, observational results of ground movement during the construction was very different with prediction during the analysis of design. step because of the uncertainty of the numerical analysis modelling, the soil parameter, and the condition of a construction field, etc. however accuratly numerical analysis method was applied. Therefore, the management system through the construction field measurement should be achieved for grasping the situation during the excavation. Until present, the measurement system restricted by ‘Absolute Value Management system’only analyzing the stability of present step was executed. So, it was difficult situation to expect the prediction of ground movement for the next excavation step. In this situation, it was developed that ‘The Management system TOMAS-EXCAV’ consisted of ‘Absolute value management system’ analyzing the stability of present step and ‘Prediction management system’ expecting the ground movement of next excavation step and analyzing the stability of next excavation step by‘Back Analysis’. TOMAS-EXCAV could be applied to all uncertainty of earth retaining structures analysis by connecting ‘Forward analysis program’ and ‘Back analysis program’ and optimizing the main design variables using SQP-MMFD optimization method through measurement results. The application of TOMAS-EXCAV was confirmed that verifed the three earth retaing construction field by back analysis.

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A Comparative Study of the Co management of Fishery Right by Fisheries Cooperatives - Centered on the Management of Fishing Ground through Eochon-gye - (수산업협동조합의 어업권관리기능에 대한 비교 연구 -어촌계의 어장관리활동을 중심으로-)

  • 최정윤
    • The Journal of Fisheries Business Administration
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    • v.29 no.2
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    • pp.21-46
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    • 1998
  • The government is largely responsible for preventing “the tragedy of the common property”, but fisherman's effort fer an autonomous fishery control is equally required. Especially in these days of EEZ such self- regulated fishery management system should be developed and cared for as well. This study aimed to explore a proper management system for coastal fishing ground that now requires the responsible fisheries management by investigating and analysing more drastically the managerial functions of fishery right by Eochon-Gye(the smallest unit of fisheries cooperative based on a fishing village), a typical fishery producer's organization in Korea. This study also included such contents as (1) an understanding of fishery producer's organization, (2) the utilization and management system of coastal fishing ground, (3) the actual condition of fishing right distribution in Korea, (4) the fishery right management and activity of Eochon-Gye, (5) the operation and distinctive feature of fishery right in Japan, (6) the intervention and limit of fishery producer's organization for fishing ground management function, and (7) summary and proposal. We made all Eochon-Gye of the whole country an object of this study and carried out an investigation into Eochon-Gye through a questionnaire. We extracted 359 Eochon-Gye, 20% of the total 1,719 Eochon-Gye as a random sample and investigated these regions through a questionnaire by mail. The contents of the questions consist of 40 items, including six categories about the organization of eochon-gye, and fishing ground management and activities.

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Estimation of Greenhouse Heating performance for Ground Filtration Water Source Heat Pump (강변여과수 열원 히트펌프 온실난방 성능시험)

  • Moon, Jongpil;Lee, Sunghyoun;Kwon, Jinkyung;Kang, YounKoo;Lee, Sujang
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.200.2-200.2
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    • 2011
  • This study was carried out in order to estimate the greenhouse performance for Ground filtration water source heat pump which was installed for supplying the heat to the paprika greenhouse in Jinju city. Experimental area of Greenhouse was $3,300m^2$, For keeping the heat from greenhouse, single plastic covering and double thermal screen was installed. With considering all of greenhouse insulation condition and designed heatng temperature, heating capacity for experimental greenhouse was calculated as 320,000kcal/hr. Coefficient of performance(COP) of Ground filtration water source heat pump was gauged and greenhouse heating performance was tested from Febuary 1 to Febuary 28 in 2011. The result showed that COP of heat pump was in the range of 3.7~4.7 and COP of heating system was in the range of 3.0~3.5. The vaule of COP was very high and the temperature inside greenhouse was well corresponded to the setting temperature of greenhouse environment controlling system. lots of Ground filtration water made the the number of well fewer and the expense for installing heating system cheaper than that of geothermal system used custmarily. and this system went beyond the limitation of intaking amount of groundwater in normal Groundwater source heat pump.

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Real-time Recognition of the Terrain Configuration to Increase Driving Stability for Unmanned Robots (안정성 향상을 위한 자율 주행 로봇의 실시간 접촉 지면 형상인식)

  • Jeon, Bongsoo;Kim, Jayoung;Lee, Jihong
    • The Journal of Korea Robotics Society
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    • v.8 no.4
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    • pp.283-291
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    • 2013
  • Methods for measuring or estimating of ground shape by a laser range finder and a vision sensor(exteroceptive sensors) have critical weakness in terms that these methods need prior database built to distinguish acquired data as unique surface condition for driving. Also, ground information by exteroceptive sensors does not reflect the deflection of ground surface caused by the movement of UGVs. Thereby, UGVs have some difficulties regarding to finding optimal driving conditions for maximum maneuverability. Therefore, this paper proposes a method of recognizing exact and precise ground shape using Inertial Measurement Unit(IMU) as a proprioceptive sensor. In this paper, firstly this method recognizes attitude of a robot in real-time using IMU and compensates attitude data of a robot with angle errors through analysis of vehicle dynamics. This method is verified by outdoor driving experiments of a real mobile robot.

An Analysis of the Farm Silo Supported by Ground (지반과 구조물 사이의 상호작용을 고려한 농업용 사이로의 해석에 관한 연구(IV) -제 4 보 관행설계법과의 비교)

  • 조진구;조현영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.2
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    • pp.44-54
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    • 1988
  • This study was carried out to investigate the applicability of the conventional design method for ground supported circular cylindrical shell structures. For this purpose, the ensiled farm silo was adopted as a model structures. Herein, the conventional design method was based on the assumption that such structures are clamped at the bottom edges or the ground pressure is independent of the deflection at the surface. In the present paper, the applicability of above assumption was checked out by comparison with an exact method considering soil-structure interaction. Some results of numerical calculation show us ; When the ground is very hard, for example Winkler's constant k is larger than 100 kg / cm$^2$ / cm, or the bottom plate of structures has a infinitely stiffness, for example the bottom plate thickness is larger than 100 cm, the sectional forces, obtained from the conventional method at any wall of structures resting on an elastic foundation, can used for design purpose. Therefore, if the above condition is satisfied then the conventional assumptions can be justified for the design purpose. In this case, the assumption that such structures are fixed at the lower edges was more realistic than the assumption that the reaction pressure acting on structures is uniformly disributed since the accuracy of results of the analysis by the former assumption was higher than that obtained from the latter assumption. But the sectional forces in the bottom plate resting on ground directly could not be evaluate correctly by the conventional method.

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Performance Analysis of a Low-Depth Unit-Type Ground Heat Exchanger using Numerical Simulation (수치해석을 통한 저심도 유닛형 지중열교환기의 성능 검토)

  • Oh, JinHwan;Seo, JangHoo;Na, Yujin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.3
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    • pp.169-173
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    • 2015
  • Recently, ground source heat pump (GSHP) systems have attracted much attention, according to the enhanced social demand of renewable energy. GSHP systems can achieve higher coefficient of performance than the conventional air-source heat pump systems by utilizing stable underground temperature. However, the initial cost of GSHP system is higher than that of the conventional systems, especially, in the small-size buildings. Therefore, it is necessary to develop small-size ground heat exchanger with low cost and quick installation. In this study, a unit-type ground heat exchanger was developed and heat exchange rate was calculated by the numerical simulation. As a result, 27.45 W/m of heat exchange rate was acquired in the condition of $0.5m{\times}0.2m{\times}2m$ unit.