• 제목/요약/키워드: Ground property

검색결과 473건 처리시간 0.027초

그라우트 재료별 열응답 특성 및 열교환기 운전온도 변화 (Thermal Response Property of Grout Materials from In-situ Test and Temperature Variation of Ground Heat Exchanger)

  • 김갑득;이성주;윤여상
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.769-775
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    • 2008
  • The objective of this report is to determine the difference of thermal response that grouted two different materials, and compare the simulation result of the length of total ground heat exchanger length that using the ground thermal conductivity. And also to know heat exchange variation of ground heat exchanger temperature that measured with various test depth. The result shows that the test hole grouted with water permeable material got better thermal response than grouted with water impermeable material. However, with consideration of ingnore for the initial 12 hour data, the test hole grouted with impermeable material has larger thermal conductivity than the other. By former thermal conductivity, simulated data by engineering program shows only 3.4% difference or less. This result shows that ground thermal conductivity is not the main variables for the design program of ground heat exchanger. At the cooling or heating mode, base on the depth of -150m, the ground heat exchanger has best temperature at $-90{\sim}-60m$ and than getting worse because of entering water heat exchanged with leaving water in the same hole.

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중국 CIETAC 중재규칙상의 보전신청에 관한 연구 (A Study on Application for Custody in CIETAC Arbitration Rule)

  • 윤진기
    • 한국중재학회지:중재연구
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    • 제13권2호
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    • pp.47-68
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    • 2004
  • The problems on application for custody in CIETAC Arbitration Rule are examined in this paper. First, The issue of jurisdiction for application for custody is arisen from the expansion of material jurisdiction of CIETAC. Until 1998, CIETAC had a jurisdiction only for the cases involving foreigners, but now, it has a jurisdiction not only for the cases involving foreigners but also for domestic cases. In the cases of arbitrating disputes involving foreigners, if the parties concerned apply for the preservation of property, CITEAC shall forward the application to and obtain a ruling from an intermediate people's court in the place where the object of the application resides, or where the property is located. But in the cases of arbitrating domestic disputes, if the parties concerned apply for the preservation of property, CITEAC shall forward the application to and obtain a ruling from an ground-level people's court in the place where the object of the application resides, or where the property is located. Therefore, "People's court" in article 23 of CIETAC Arbitration Rule includes both intermediate people's court and ground-level people's court in its meaning. Second, in the cases that the party concerned submits arbitration to CIETAC, it is not permitted for the party to ask the people's court for custody of property before submitting an arbitration. But there still can be the urgent cases that interests of the party concerned are at stake, and legitimate rights and interests of the party concerned may be damaged beyond remedy, if no application for custody of property is filed immediately. In that cases, even if the party may apply for custody of property with the people's court after submitting an arbitration, it might be too late to preserve property. Therefore, Chinese laws and rules have to be revised so that the party may ask the people's court for custody of property before submitting an arbitration. When revising laws and rules, according to the today's legislation trends, it must be considered that court and arbitration tribunal both have a right to decide the custody of property. When arbitration tribunal decides it, the procedural provisions executing it must be provided. It is also required that China permit to apply preservation of evidence as well as custody of property before submitting an arbitration. It is also strongly recommended that China permit custody of property or preservation of evidence even in the cases that an arbitration is submitted to the arbitration institute which is located in foreign country, not in China.

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MIMO Antenna Using Resonance of Ground Planes for 4G Mobile Application

  • Zhao, Xing;Kwon, Kyeol;Choi, Jeahoon
    • Journal of electromagnetic engineering and science
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    • 제13권1호
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    • pp.51-53
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    • 2013
  • A MIMO antenna using the resonance of ground planes is proposed for 4G mobile application. A resonant mode is generated when the double ground planes (upper and lower) in the mobile terminal are excited as the radiator. By combining the resonant modes contributed from both the antenna element and the ground planes, the proposed MIMO antenna realizes a wideband property over LTE band 13. In addition, an inductive coil is employed to reduce the antenna volume. These approaches not only simplify antenna design but also effectively improve bandwidth and efficiency. The proposed MIMO antenna has an excellent ECC value of below 0.1 because of the nearly orthogonal radiation patterns of the two radiators. Moreover, an additional antenna is adopted to cover WiMAX, WLAN, and Bluetooth services simultaneously in frequency range from 2 GHz to 2.7 GHz.

수치해석에 의한 쇄석말뚝의 지지력 특성 고찰 (A Study on the Bearing Capacity characteristics of Stone column by Numerical Analysis)

  • 천병식;김백영
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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    • pp.90-99
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    • 2004
  • Stone column is one of the soft ground improvement method, which enhances ground conditions through ground water draining, settlement reducing and bearing capacity increasing complexly by using crushed stone instead of sand in general vertical drain methods. In recent, general construction material, sand is in short of supply, because of the unbalance of demand and supply. Also, the bearing capacity improving effect of stone column method is needed in many cases so the bearing capacity estimation is considered as important point. Nevertheless, adequate estimation methods to predict bearing capacity of stone column considering stone column and improving ground behavior reciprocally is not yet prepared. To contribute this situation, bearing capacity behavior of stone column were simulated as numerically on various property cases of crushed stone and surrounded ground. Through the numerical analysis of simulation results, bearing capacity behavior prediction formula was suggested. This formula was verified by comparing the prediction result with in situ test.

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생석회 말뚝을 이용한 연약점토지반의 개량효과 (Improvement Effects of Soft Clay Soils Using Quick Lime Piles)

  • 김영훈;천병식
    • 한국지반환경공학회 논문집
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    • 제11권5호
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    • pp.45-51
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    • 2010
  • 본 연구에서는 생석회 말뚝에 의한 연약지반 안정처리공법으로써의 현장 적용성을 평가하기 위하여 한국산 생석회에 대한 공학적 특성 규명은 물론 지중에서의 생석회에 의한 지반개량 원리 및 주변지반의 개량특성에 대한 이론적 고찰과 함께 실내모형시험을 수행하여 이를 바탕으로 실제 현장에서의 적용성과 활용성을 평가하고자 하였다. 실험결과 생석회 말뚝 공법은 생석회의 소화 흡수에 의한 탈수효과, 말뚝의 팽창에 의한 압밀효과 및 말뚝 자체의 강도에 의한 지지력 증가, 침하감소 효과 등의 개량효과를 얻을 수 있는 것으로 평가되었다. 생석회는 재료 특성이 매우 양호하여 그 자체로써 상당한 강도를 가지고 있으나 보다 큰 강도가 요구될 시에는 시멘트 등을 첨가하면 효과가 있을 것으로 판단된다.

지반 응답 해석 Round Robin Test의 입력 지반 물성에 따른 지반 응답 특성 영향 고찰 (Effect of Input Soil Properties for Round Robin Test on Ground Response Analysis)

  • 김동수;이세현;추연욱;박성식;김동준
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2007년 가을학술발표회
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    • pp.305-316
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    • 2007
  • Free field ground motion during earthquake is significantly affected by the local soil conditions and it is essential for the seismic design to perform the site specific ground response analysis. So, Round Robin Test (RRT) on ground response analysis was performed for three sites in Korea. A total of 12 teams presented the results of ground response analysis with used input soil properties based on own judgement. In this paper, the results of one dimensional equivalent linear analysis presented by 11 teams were compared to evaluate the effect of input soil properties on ground response analysis. Additionally, 4 influence factors on ground response analysis, that is shear wave velocity of soil layer, nonlinear dynamic deformational characteristics, bedrock depth and bedrock velocity were studied for assumed simple soil conditions.

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역해석을 통한 소단굴착에 따른 흙막이 벽체변위의 매개변수 연구 (Parametric Study on Displacement of Earth Retaining Wall by the Bermed Excavation Using Back Analysis)

  • 이명한;김태형
    • 한국지반신소재학회논문집
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    • 제14권4호
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    • pp.23-33
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    • 2015
  • 소단은 굴착 후 지지구조물이 설치되기 전 벽체의 강성과 더불어 가설벽체의 안정성을 좌우하는 역할을 한다. 특히 굴착지반이 느슨하거나 연약한 경우 소단의 역할은 매우 중요하다. 본 연구에서는 소단을 이용한 도심지 버팀굴착현장의 계측결과와 수치해석을 사용하여 가설벽체의 최대수평변위에 미치는 소단의 규모(폭과 경사) 및 굴착깊이, 지반물성의 영향을 분석하였다. 계측결과 소단 폭이 짧아질수록 벽체의 수평변위는 증가하는 경향을 보였다. 수치해석 결과 소단의 경사가 급해질수록, 소단폭이 짧아질수록 최대수평변위량은 크게 나타나 소단이 벽체의 변위를 억제하는데 효과가 있음을 알 수 있었다. 또한 굴착심도가 깊어질수록 소단폭과 경사의 영향을 크게 받는 것으로 나타났다. 동일한 소단 조건에서 지반물성이 높을수록 벽체의 최대수평변위를 억제하는 것으로 나타났다.

난용성 약물의 용출 증가 (제 3 보) -키틴 또는 키토산과의 혼합분쇄물로부터의 푸로세미드의 용출 증가- (Enhancement of Dissolution Properties of Poorly Soluble Drugs (III) -Dissolution Enhancement of Furosemide from Ground Mixtures with Chitin or Chitosan-)

  • 신상철;오인준;이강춘;이용복;고익배
    • Journal of Pharmaceutical Investigation
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    • 제17권4호
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    • pp.175-181
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    • 1987
  • To increase the dissolution rate of furosemide, chitin and chitosan which are widely occurring biodegradable natural materials were used as drug carriers. The ground mixtures of furosemide with chitin or chitosan were prepared by grinding in a ball mill. The ground mixture showed a faster and more enhanced dissolution rate than the physical mixture or intact furosemide. The crystalline peaks of furosemide disappeared in the ground mixtures indicating the production of amorphous form. The comparison of infrared spectra of the physical mixture and the ground mixture showed an interaction such as association between the functional groups of furosemide and chitin or chitosan in the molecular level. The weight losses in TGA curves showed all the same patterns. However, the endothermic peak due to the fusion of furosemide in DTA curve disappeared in the ground mixture indicating the different thermal property. The dissolution of furosemide from ground mixtures was fast in the order of chitosan and then chitin. The co-grinding technique with chitin or chitosan provided a promising way enhancing the dissolution rate of practically insoluble drug.

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강제치환 거동특성에 관한 원심모형실험 (Centrifuge Model Experiments on Behaviour Characterisitc in Forced Replacement Method)

  • 이종호;박병수;정길수;유남재
    • 산업기술연구
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    • 제23권A호
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    • pp.131-137
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    • 2003
  • This thesis is results of centrifuge model experiments to investigate the behavior of replacement method in dredged and reclaimed ground. For experimental works, centrifuge model tests were carried out to investigate the behavior of replacement method in soft clay ground. Basic soil property tests were performed to find mechanical properties of clay soil sampled from the southern coast of Korea which was used for ground material in the centrifuge model tests. Reconstituted clay ground of model was prepared by applying preconsolidation pressure in 1g condition with specially built model container. Centrifuge model tests were carried out under the artificially accelerated gravitational level of 50g. Replacing material of leads having a certain degree of angularity was used and placed until the settlement of embankment of replacing material was reached to the equilibrium state. Vertical displacement of replacing material was monitored during tests. Depth and shape of replacement, especially the slope of penetrated replacing material and water contents of clay ground were measured after finishing tests. Model tests of investigating the stability of embankment after backfilling were also performed to simulate the behavior of the dike treated with replacement and backfilled with sandy material. As a result of centrifuge model test, the behavior of replacement, the mechanism of the replacing material being penetrated into clay ground and depth of replacement were evaluated.

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지면효과를 갖는 직렬 에어포일 주위의 공력 해석에 관한 연구 (A Study on the Aerodynamic Analysis of Tandem Airfoil under Ground Effect)

  • 임예훈;장근식
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 1999년도 추계 학술대회논문집
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    • pp.174-180
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    • 1999
  • Aerodynamic characteristics of tandem airfoil under ground effect is investigated numerically. Some numerical results for NACA 6409 tandem airfoil are presented. The numerical results show that as being decreased distance between airfoils, the lift coefficient of leading airfoil is increased and that of trailing airfoil is decreased. Drag coefficient shows opposite property, At the same distance between leading airfoil and trailing airfoil, lower position of trailing airfoil give better tandem airfoil effect.

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