• Title/Summary/Keyword: Bare ground

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A Development of Device for Measurement of Vertical Ground Reaction Force(II) (수직 반작용력 측정 장치 개발(II))

  • Park, Jin
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.341-354
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    • 2003
  • The purpose of this study was to develop the uniaxial force plate system which is measured by the vertical force. The VGRF(vertical ground reaction force) 1.0 was composed of 2 bath digital scales, 2 indicaters, and analyzing software. This system was newly renovated to VGRF 2,0 which are 2 industrial digital scales, 2 adjustable indicators, and enforced analyzing software. Changes of the new system were as follows. First, the height of the plate was 75% lower than before. Second, sensing ability of the load cell was changed from 90 - 0.05kg to 300 - 0.1kg. Third, the speed of data processing was changed from 17 per second to 60 per second. Fourth, analyzing software was enforced to develop and calculate the data. For the test of the system, two different types(bare foot, high-heeled shoes) gait was adopted. highly skilled female walker(23yrs, height 165cm, body mass 46.8kg) participated for the experimental study. During the dynamic performance(gait analysis), the data of each load cell were very similar to the previous studies. Specifically, bare foot walking had less vertical force than high-heeled shoes. Consequently, VGRF 2.0 can sense the general dynamic movements as well as static load conditions.

A Study on the Proper Definition of Ground Level under the Building Act - Difference of heights which is over 3 meters - (고저차 3m 이상 지표면의 가중평균지표면 산정방법에 관한 연구)

  • Min, Young-Gi;Kim, Soo-Young
    • Journal of The Korean Digital Architecture Interior Association
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    • v.9 no.1
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    • pp.91-98
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    • 2009
  • My questionaire survey revealed that even those experts that engage in architectural design did not precisely understand much of the regulations concerning ground-level. In terms of restricting the size of the building area, the generous policy of excluding balconies and basements from the calculation of building size actually causes problems. As far as the right to sunshine is concerned, the weighted average ground-level is determined to be the ground-level standard of the neighboring plot when the neighboring plot is a sloping bare ground. When the difference of heights is over 3 meters, it would be appropriate to assess the weighted ground-level standard every 3 meters.

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On the Evapotranspiration Model derived from the Meteorological Elements and Penman equation (Penman 식과 기상요소를 이용한 증발산모델에 관하여)

  • 이광호
    • Water for future
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    • v.6 no.2
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    • pp.6-11
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    • 1973
  • This paper include the hydrometeorological analyses of evapotranspiration which is import factor concerning the estimate of water budgest over a certain basin. Evapotranspiration model mode by the multiple regression analysis between the evapotranspiration measured on various kinds of ground cover (water, bare soil and lawn) and the other meteorological elements affecting the evapotranspiration process, and the simple regression analysis between the evapo transpiration measured on each ground cover and the evapotranspiration on water and vegetables calculated from the Penman equation. It is expected that the evapotranspiration models are a very useful formulae estimating ten days amounts or a month's amounts.

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Front-to-Back Ratio Improvement of a Microstrip Patch Antenna Loaded with Soft Surface Structure in a Partially Removed Ground Plane

  • Lee, Hong-Min
    • Journal of electromagnetic engineering and science
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    • v.12 no.4
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    • pp.247-253
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    • 2012
  • This study presents a new, simple method for improving the front-to-back (F/B) ratio of a microstrip patch antenna. The back radiation of the microstrip patch antenna is reduced by removing some metallic parts around the ground plane and placing a new soft-surface configuration, consisting of an array of stand-up split-ring resonators on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional microstrip patch antenna with a full ground plane of the same size, our proposed microstrip patch antenna experimentally achieves an improved F/B ratio of 9.6 dB.

Studies on the soil freezing depth and change of moisture contents in evergreen plants upon subzero temperature in (강원도지역의 토양동결심 및 상록식물의 함수량 추이에 관한연구 (1))

  • 홍종운;허범양;원경열;임병춘;이기철;하상건
    • Asian Journal of Turfgrass Science
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    • v.4 no.1
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    • pp.42-48
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    • 1990
  • Experiments were conducted to investigate the soil freezing depth and pattern with freezing measuring instruments during 1988-l989 winter season in Kangwon province. Freezing measuring instrument was made with acrylic pipes which were consisted of inner and outer parts. Inner pipe was filled with 0.01 % methylene blue solution and rubber hose to protect pipe breakdown by solution freezing. Freezing measurements were carried out by observing discoloration of methylene blue solution. Moisture content of evergreen trees and ground cover plants was also examined in the winter season. The observed results are as follows: 1.In the land of I OOM above sea level, soil freezing depth became deeper as the sum of Accumulated degree-days of temperature below 0˚C(0˚C . day) increased: Soil freezing depth was 30-40cm at l00˚C, 42-43cm at 150˚C, and 47cm at 200˚C day 2.Soil freezing with vinyl mulching was less developed by l3cm at l00˚C with sum of subzero temperature, by l7cm at 200˚C than that of the bare ground. Soil of rich hulls mulching with 4Ocm was not frozen until soil freezing at the bare ground was developed to 25cm depth. 3.Cashmeron mulching was more effective than felt mulching in the heat insulation of soil. 4.Thawing of soil was done from the lowest part of the frozen in the ground to upward in the beginning and after that it was done from the surface of frozen soil to downward. Finally thawing was completed at the middle of frozen soil.

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Kinetics Analysis during Stance Phase of Fore Foot Contact versus Rear Foot Contact in Running

  • Cho, Woong;Han, Jae Woong;Kim, A Young;Park, Sung Kyu;Kim, Hyung Soo
    • Journal of International Academy of Physical Therapy Research
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    • v.8 no.1
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    • pp.1084-1089
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    • 2017
  • The purpose of this study was to compare and analyze the difference of the ankle joint movements during landing. Seven adult males voluntarily participated in the study and the average foot size of the subjects was 269.8 mm. Image analysis equipment and the ground reaction force plate (landing type) was used to measure th kinetic variables. As a result of this study, it was confirmed that the vertical ground reaction force peak point appeared once in the barefoot with forefoot, while two peak points appeared in the barefoot and functional shoe foot with rear foot landing. About ankle angle, fore foot landing ankle angle, the average with bare foot landing was $-10.302^{\circ}$ and the average with functional shoe foot landing was $-2.919^{\circ}$. Also about rear foot landing, ankle angle was $11.648^{\circ}$ with bare foot landing and $15.994^{\circ}$ with functional shoe landing. The fore foot landing, ankle joint force analysis produced 1423.966N with barefoot and 1493.264N with functional shoes. But, the rear foot landing, ankle joint force analysis produced 1680.154N with barefoot and 1657.286N with functional shoes. This study suggest that the angle of ankle depends on the landing type and bare foot running/functionalized shod running, and ankle joint forces also depends on landing type.

Composite Beam Element for Nonlinear Seismic Analysis of Steel Frames (강재 골조의 비선형 지진해석을 위한 합성 보 요소)

  • Kim, Kee Dong;Ko, Man Gi;Yi, Gyu Sei;Hwang, Byoung Kuk
    • Journal of Korean Society of Steel Construction
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    • v.14 no.5 s.60
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    • pp.577-591
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    • 2002
  • This study presented a composite beam element for modeling the inelastic behavior of the steel beam, which has composite slabs in steel moment frames that are subjected to earthquake ground motions. The effects of composite slabs on the seismic behavior of steel moment frames were investigated. The element can be considered as a single-component series hinge type model whose predicted analytical results were consistent with the experimental results. Likewise, the element showed a significantly better performance than the bare steel beam elements. The composite model can also predict more accurately the local deformation demands and overall response of structural systems under earthquake loading compared with the bare steel models. Therefore, composite stabs can significantly affect locally and globally predicted responses of steel moment frames.

A Semi-empirical Model for Microwave Polarimetric Radar Backscattering from Bare Soil Surfaces

  • Oh, Yi-Sok
    • Korean Journal of Remote Sensing
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    • v.10 no.2
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    • pp.17-35
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    • 1994
  • A semi-empirical model for microwave polarimetric radar backscattering from bare soil surfaces was developed using polarmetric radar measurements and the knowledge based on the theoretical and numerical solutions. The microwave polarimetric backscatter measurements were conducted for bare soil surfaces under a variety of roughness and moisture conditions at L-, C-, and X-band frequencies at incidence angles ranging from 10` to 70`. Since the accrate target parameters as well as the radar parameters are necessary for radar scattering modeling, a complete and accurate set of ground truth data were also collected using a laser profile meter and dielectric probes for each surface condition, from which accurate measurements were made of the rms height, correlation length, and dielectric constant. At first, the angular and spectral dependencies of the measured radar backscatter for a wide range of roughnesses and moisture conditions are examined. Then, the measured scattering behavior was tested using theoretical and numerical solutions. Based on the experimental observations and the theoretical and numerical solutions, a semi-empirical model was developed for backscattering coeffients in terms of the surface roughness parameters and the relative dielectric constant of the soil surface. The model was found to yield very good agreement with the backscattering measurements of this study as well as with independent measurements.

Displacement-based seismic design of open ground storey buildings

  • Varughese, Jiji Anna;Menon, Devdas;Prasad, A. Meher
    • Structural Engineering and Mechanics
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    • v.54 no.1
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    • pp.19-33
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    • 2015
  • Open ground storey (OGS) buildings are characterized by the sudden reduction of stiffness in the ground storey with respect to the upper infilled storeys. During earthquakes, this vertical irregularity may result in accumulated damage in the ground storey members of OGS buildings without much damage in the upper storeys. Hence, the structural design of OGS buildings needs special attention. The present study suggests a modification of existing displacement-based design (DBD) procedure by proposing a new lateral load distribution. The increased demands of ground storey members of OGS buildings are estimated based on non-linear time history analysis results of four sets of bare and OGS frames having four to ten storey heights. The relationship between the increased demand and the relative stiffness of ground storey (with respect to upper storeys) is taken as the criterion for developing the expression for the design lateral load. It is also observed that under far-field earthquakes, there is a decrease in the ground storey drift of OGS frames as the height of the frame increases, whereas there is no such reduction when these frames are subjected to near-field earthquakes.

Analysis of NPS Pollution Loads over Rainfall-Runoff Events from the Silica Mine Site (규사광산 지역의 강우시 비점오염원의 유출분석)

  • Choi, Yong-hun;Won, Chul-hee;Seo, Ji-yeon;Shin, Min-Hwan;Yang, Hee-Jeong;Choi, Joong-dae
    • Journal of Korean Society on Water Environment
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    • v.26 no.3
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    • pp.413-419
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    • 2010
  • A silica mine monitoring was conducted from March to December in 2008 to measure rainfall, runoff amounts and pollution loads. A total of 13 rainfall-runoff events were measured and analyzed with respect to runoff ratio, pollutant concentration and load, and initial flush. Over rainfall-runoff events, 95% confidence range of SS concentration was 942.5~2,056.2 mg/L. Other measured water quality indices also showed relatively large variation. This wide concentration variation was thought to be caused by the bare working ground of the mine that was used to store, process and transport the mined silica. Total pollution load of the 13 rainfall-runoff events was SS 17,901 kg/ha, $COD_{Cr}$ 160.9 kg/ha, $COD_{Mn}$ 111.24 kg/ha, BOD 79.6 kg/ha, T-N 13.8 kg/ha, T-P 3.5 kg/ha, and TOC 39.3 kg/ha. Initial flush was not well observed except SS. Very high SS concentration and load was occurred when rainfall was large. Therefore, it was recommended to manage the bare ground not to discharge excessive pollutants during wet days by covering the ground or constructing runoff treatment systems such as a sediment basin.