• 제목/요약/키워드: Horizontal distribution

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수압파쇄법에 의한 국내 과잉 수평응력 분포 특성에 관한 연구 (Characteristics of Excessive Horizontal Stress in Korea by Hydraulic Fracturing Stress Measurement)

  • 배성호;전석원;김학수;김재민
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.431-438
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    • 2005
  • In this paper, the characteristics of excessive horizontal stress components in Korea were studied using the in-situ hydraulic fracturing stress measurement data over five hundred in 110 individual test boreholes. Based on the in-situ testing data, the magnitude and orientation of the horizontal stress component and variation of stress ratio (K) with depth were investigated. And also horizontal stress magnitude versus depth relationships and distribution limits of stress ratio components were suggested. For the subsurface space above 310 m depth in the entire territory, the stress ratio has a tendency to diminish and be stabilized with depth, but for some areas, it was revealed that the excessive horizontal stress fields with stress ratio close to 3.0 below 200 m in depth have formed. The result of investigation for excessive horizontal stress regions indicates that there exist several regions above 300 m in depth where localized excessive horizontal stresses enough to induce potentially brittle failure around future openings have formed.

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Factors Influencing Horizontal Cooperation Among Logistics Enterprises: An Empirical Study from Vietnam

  • LE, Son Tung;PHAM, Thi Yen;DAO, Van Thi;PHUNG, Manh Trung
    • The Journal of Asian Finance, Economics and Business
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    • 제8권12호
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    • pp.313-322
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    • 2021
  • Horizontal cooperation is seen as an effective way to raise a competitive advantage in logistics and transportation. However, there are many logistics enterprises still operating individually instead of cooperating. This research aims to investigate the factors influencing the decision of horizontal cooperation by surveying a large sample of Vietnamese logistics companies. This study employs 161 logistics companies to examine correlations between potential factors and horizontal collaboration. The structural equation model (SEM) was used to test the conceptual model and the relationships among variables. The findings revealed that information sharing was the most important predictor of 161 supply chain providers' horizontal collaboration decisions, which resulted in increased profitability or service quality. Besides, trust in partners was found to be positively related to the degree of horizontal cooperation among logistics companies. Finally, the finding of this research is that reputation had a positive effect on the strategy of horizontal cooperation. Our findings suggest that SME managers should be concerened about their information sharing, their reputation as well as their trust in partners if they would be invited in cooperation with another firm to increase service quality, performance, and competitive advantage.

수평배수재를 이용한 압밀개량효과에 대한 실험연구 (An Experimental Study on the Effect of Consolidation Improvement Using Horizontal Drains)

  • 김지용;김정기;장연수;김수삼
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.33-40
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    • 2000
  • The horizontal drain method is one of the soil improvement methods in reclamation works using dredged soils. In this method, plastic drain boards are installed horizontally in the ground, and a seepage pressure or negative pressure is applied through one end of these drains. In this study, a basic consolidation test using horizontal drains was conducted to investigate the effectiveness of this method. The configuration of soil box which was used in this test is 100cm(B)${\times}$100cm(L)${\times}$85cm(H). The drain board was reduced to 25mm${\times}$5mm. The variations in settlement and volume of drain water during the consolidation process were measured, and the distribution of water content and the transpormation of horizontal drain were investigated.

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수평Y자형 분지관에서 증기-물 이상류의 상분리에 관한 실험적 연구 (Experimental Studies on Phase Separation of Steam-Water Two Phase Flow in Horizontal Y-Branching Conduit)

  • 안수환
    • 대한기계학회논문집B
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    • 제24권6호
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    • pp.886-893
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    • 2000
  • The Characteristics of dividing the dispersed bubble, plug, and slug steam-water flow in the horizontal junctions with horizontal branches have been experimentally investigated. The experimental investigation of the separation phenomena in a $45^{\circ}$ horizontal wye with equal pipe inner diameter of 25 mm is presented to provide a data base for the development and verification of the analytical models. The phase separation and pressure distribution in the three legs of each test section are obtained through the set of measurements made in the present work. And the dependence of phase separation on different parameters, such as inlet quality and mass flux, is discussed.

해안 곰솔림 내 아까시나무의 분포확대 억제요인 (Inhibitory Factors of Robinia pseudoacacia Distribution in a Pinus thunbergii Forest at the Coast)

  • 정성철;구교상;김경하
    • 한국환경생태학회지
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    • 제25권5호
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    • pp.717-724
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    • 2011
  • 본 연구는 해안 곰솔림에 생육하고 있는 아까시나무의 분포특성을 결정하는 요인을 구명하기 위하여 아까시나무의 생장특성과 임내 환경을 조사 분석하였다. 해안 곰솔림 내에 분포하고 있는 아까시나무의 분포확대 억제요인을 분석한 결과, 염분농도가 높은 0m 지점에서 잎의 갈변, 위조, 조기낙엽 현상이 나타나 염분이 아까시나무의 생장억제에 큰 영향을 미치는 요인으로 추정되었다. 그러나 토양특성과 광환경은 식재지점간의 차이는 나타나지 않아 아까시나무의 생장에 있어 큰 영향을 주지 않는 것으로 추정되었다. 또한 해안측에 생장하고 있는 아까시나무의 수평근 연륜분석 결과, 2년생 개체의 근주에서 0.1~0.2m 떨어진 수평근 연륜에서도 1년 밖에 형성되지 않아 아까시나무의 수평근으로 영양공급이 충분하게 이루어지지 않아 수평근의 신장을 억제하는 것으로 추정되었다. 따라서 새로운 수평근의 신장과 개체의 신생이 이루어지지 않아 해안측으로 아까시나무의 분포확대가 억제되는 것으로 사료되었다.

황금 분할 마스크를 이용한 대학생 안면의 수평적 분석 (Horizontal Ratio of the Korean University Student's Face and Facial Golden Mask)

  • 이준호;박건욱;김용하
    • Archives of Plastic Surgery
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    • 제35권5호
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    • pp.514-520
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    • 2008
  • Purpose: Many attempts have been made to describe ideal facial proportions for over two thousands year and constantly lasted till now. Dr. Marquardt has derived supposedly ideal facial proportions from the facial golden mask using golden ratio of 1 : 1.618. On the other hand, facial reducing surgeries such as mandible angle reduction are popularized in Asia because the width of mid and lower face of Korean is recognized to be wider. The purpose is to analyze characters of Korean university students' faces in horizontal plane and establish the objective data for facial width distributions and clinical applications. Methods: We applied the facial golden mask to the photographs in 1000 cases, compared the width of mid and lower face between the facial golden mask and Korean university students' faces. And we first calculated the horizontal ratio(HR) of middle and lower face each for using comparative scale of width, facial golden mask. We divided 1,000 cases into 3 groups by degrees of HR and analyzed data of HR on each groups. Using calculated horizontal ratio, we newly invented the cumulative frequency of distribution graphs in Korean university students' faces. Results: Mean data of HR were over 1.0 in all groups, which means that Korean university students' faces are typically wider than facial golden mask in horizontal planes. And this study was statistically significant(p- value < 0.05). Clinically using the cumulative frequency distributions of Korean university students' face width, we can easily explain changes of facial width to patient after facial reducing surgery and describe the changes into objective data. Conclusion: This study concludes thatKorean university students' faces are wider than facial golden mask is significantly true and the cumulative frequency of distribution graphs are expected to be widely used for comparison of results in facial reducing surgery.

Seismic lateral earth pressure analysis of retaining walls

  • Ismeik, Muhannad;Shaqour, Fathi
    • Geomechanics and Engineering
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    • 제8권4호
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    • pp.523-540
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    • 2015
  • Based on limit equilibrium principles, this study presents a theoretical derivation of a new analytical formulation for estimating magnitude and lateral earth pressure distribution on a retaining wall subjected to seismic loads. The proposed solution accounts for failure wedge inclination, unit weight and friction angle of backfill soil, wall roughness, and horizontal and vertical seismic ground accelerations. The current analysis predicts a nonlinear lateral earth pressure variation along the wall with and without seismic loads. A parametric study is conducted to examine the influence of various parameters on lateral earth pressure distribution. Findings reveal that lateral earth pressure increases with the increase of horizontal ground acceleration while it decreases with the increase of vertical ground acceleration. Compared to classical theory, the position of resultant lateral earth force is located at a higher distance from wall base which in turn has a direct impact on wall stability and economy. A numerical example is presented to illustrate the computations of lateral earth pressure distribution based on the suggested analytical method.

원관 주위의 대류 열전달에 대한 복합 열전달 (Conjugated heat transfer on convection heat transfer from a circular tube in cross flow)

  • 이승홍;이억수;정은행
    • 설비공학논문집
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    • 제10권5호
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    • pp.523-534
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    • 1998
  • The convection heat transfer on horizontal circular tube is studied as a conjugated heat transfer problem. With uniform heat generation in a cylindrical heater placed in a cross flow boundary condition, heat flow that is conducted along the wall of the heater creates a non-isothermal surface temperature and non-uniform heat flux distribution. In the present investigation, the effects of circumferential wall heat conduction on convection heat transfer are investigated for the case of forced convection around horizontal circular tube in cross flow of air and water. Non-dimensional conjugation parameter $ K^*$ which can be deduced from the governing energy differential equation should be used to express the effect of circumferential wall heat conduction. Two-dimensional temperature distribution$ T({\gamma,\theta})$ is presented. The influence of circumferential wall heat conduction is demonstrated on graph of local Nusselt number.

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고유주기에 따른 건축물의 수평진동에 대한 거주자의 허용가속도평가 (Evaluate of allowable acceleration for Occupants in Horizontal Vibration of Buildings according to Natural Frequency)

  • 조강표;정승환;조기성
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2008년도 정기 학술대회
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    • pp.228-233
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    • 2008
  • In this paper, peak acceleration for horizontal vibration of buildings was estimated from the results of vibration tests using a shaking table. Human comfort of occupants is supposed to be satisfied according to the peak acceleration in NBCC and ISO6897, which have been used by Korean structural engineers. In the paper, we used a one-dimensional shaking table for horizontal vibration tests, which was mounted with a vibration house similar to a living space. Experimental results were obtained according to increasing accelerations in the range of 0.2Hz through 1.2Hz of frequency with five experimental groups, each of which was composed of eight persons. We obtained performance curves by dividing the distribution of perception from horizontal vibration tests into the ranges of 0${\sim}$25%, 26${\sim}$50%, 51${\sim}$75%, 76${\sim}$100% and then fitting the curves. Also we made a questionnaire based on human comfort criteria of foreign countries, and examined the feelings of subjects. From the results of horizontal vibration tests, it was found that acceleration of perception was low when frequency was high, and that visual and auditory senses affect the human perception for horizontal vibration of buildings.

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한반도 3차원 지중응력의 분포와 이를 고려한 터널해석에 대한 연구 (Three Dimensional In-situ Stress Distribution in the Southern Korean Peninsula and Its Application in Tunnel Analysis)

  • 김동갑;박종관
    • 한국지반공학회논문집
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    • 제18권2호
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    • pp.65-74
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    • 2002
  • 지중응력의 측정은 터널 및 지하구조물의 변위와 응력분포를 예측하는데 중요하다. 본 연구에서는 남부 한반도 지역의 지중응력 분포를 음력해방법과 수압파쇄법으로 측정된 새로운 380개의 자료를 통하여 재평가와 이를 고려한 삼차원 터널해석을 실시하였다. 지중응력분포의 결과에 의하면 변성암과 화강암지역의 수평응력분포는 퇴적암과 화산암의 분포에 비하여 불규칙한 경향을 보이고 있다. 화산암 지역에서는 수직응력에 대한 수평음력의 비(측압계수, K)는 150m 깊이 이상 심도에서 1보다 작다. 또한, 국내에서는 처음으로 측정된 지중응력에 대한 삼차원 방향과 크기를 동시에 그림으로 나타내었다. 삼차원 터널 해석에 의하면, 터널 주변의 변위에 대한 방향과 크기는 최대수평음력과 최소수평응력의 차이에 의하여 주로 영향을 받고 있다.