• Title/Summary/Keyword: Drain capacity

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Human Capacity Issues Along the STEM Pipeline

  • Melkers, Julia
    • STI Policy Review
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    • v.1 no.2
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    • pp.1-18
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    • 2010
  • The development and maintenance of human capacity in economies is critical to long term competitiveness, but also for the overall health and environment of regions. Yet, human science and technology-based capacity is multidimensional and has interrelated characteristics which present certain policy challenges. This paper addresses a range of issues specific to a discussion on human capacity in S&T. First, the paper emphasizes the importance of acknowledging the complexity of human capacity issues and how they evolve along the STEM (science, technology, engineering, and mathematics) pipeline. The pipeline is an often used reference to describe the training and development in STEM disciplines, from early childhood education, to more advanced training, and finally to professional collaboration and interaction and serves as a useful organizing framework for the discussion of capacity along the career evolution process. Second, the paper offers an organizing framework for discussion of policy mechanisms that have been developed to address issues and gaps that occur along this STEM pipeline. Specifically, it contrasts the traditional mechanisms of building human capacity in STEM areas with newer "gap filling" and integrated approached to addressed human capacity disparities and priorities. Third, the paper addresses core challenges in human capacity in STEM, including the education and training, participation of women and underrepresented groups, brain drain/brain circulation issues, and the globalization of science. The paper concludes with a discussion of policy implication for the development of human capacity.

Analysis of seepage in trenching for surface desiccation of dredged soft ground (준설매립지반 표층건조처리를 위한 트렌치 굴착시 간극수의 침투해석)

  • 정하익;오인규;이용길;이승원;이영남
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.529-536
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    • 2002
  • The purpose of this paper os to present and discuss some of flow and drain observed in modelling results. Because dredged fill ground of Yul-Chon located in the south coast of Korea is very soft, this ground should be improved after operation of surface stabilization. There are surface stabilization method such as chemical stabilization, desiccation, horizontally vacuum drain, replacement, and geosynthetics. In Yul-Chon, PTM(Progressive Trenching Method) is adopted to provide the necessity condition of surface desiccation. In the case trench in the dredged soft ground is formed by PTM equipment, pore water in the ground is drained through trench. There, drain and desiccation of surface ground increase, and bearing capacity is improved. In this research, when trench in the dredged soft ground is formed by PTM equipment, permeable characteristics and drain efficiency of pore-water are analyzed using SEEP/W software package. Results show variation of total head, pressure head, flux, hydraulic gradient, and flow quantity.

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A Study on the Drainage Effects of Gravel Drain by Laboratory Model Test (실내모형시험을 통한 Gravel Drain의 배수효과에 관한 연구)

  • 천병식;김백영;고용일;여유현;박경원
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.87-94
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    • 1999
  • Sand drain as a vertical drainage is widely used in soft ground improvement. Recently, sand, the principal source of sand drain, is running out. A laboratory model test was carried out to utilize gravel as a substitute for sand. Though which the characteristics of gravel are compared to those of sand for engineering purpose. Two cylindrical containers for the model test were filled with marine clayey soil from the west coast of Korea with a column in the center, one with sand, the other with gravel. Vibrating wire type piezometers were installed at the distance of 1.0D, 1.5D and 2.0D from the center of the column. D is the diameter of the column. The transient process of pore water pressure with loading and the characteristics of consolidation were studied with the data gained from the measuring instrument place on the surface of the container. The parameter study was performed for the marine clayey soil before and after the test in order to check the effectiveness of the improvement. The clogging effect was checked at various depth in gravel column after the test. According to the test, the settlement was found to be smaller in gravel drain than in sand drain. The increase in bearing capacity by gravel pile explains the result. The clogging effect was not found in gravel column. As a result, it is assumed that gravel is relatively acceptable as a drainage material.

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Consolidation Behavior of Soft Ground by Prefabricated Vertical Drains (연직드레인 공법에 의한 연약지반의 압밀거동)

  • 이달원;강예묵
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.376-381
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    • 1998
  • The large scaled field test by prefabricated vertical drains was performed to evaluate the superiority of vertical discharge capacity for drain materials through compare and analyze the time-settlement behavior with drain spacing and the compression index and consolidation coefficient obtained by laboratory experiments and field monitoring system 1. The relation of measurement settlement( $S_{m}$) versus design settlement( $S_{t}$) and measurement consolidation ratio( $U_{m}$) versus design consolidation ratio( $U_{t}$) were shown $S_{m}$=(1.0~l.1) $S_{t}$, $U_{m}$=(1.13~l.17) $U_{t}$, at 1.0m drain spacing and $S_{m}$=(0.7~0.8) $S_{t}$, $U_{m}$=(0.92~0.99) $U_{t}$ at 1.5m drain spacing, respectively. 2. The relation of field compression index( $C_{cfield}$) and virgin compression index( $V_{cclab}$) was shown $C_{cfield}$=(1.0~1.2) $V_{cclab}$, But it was nearly same value when considered the error with determination method of virgin compression index and prediction method of total settlement. 3. field consolidation coefficient was larger than laboratory consolidation coefficient, and the consolidation coefficient ratio( $C_{h}$/ $C_{v}$) were $C_{h}$=(2.4 ~ 3.0) $C_{v}$. $C_{h}$=(3.5 ~ 4.3) $C_{v}$ at 1.0m and 1.5m drain spacing and increased with increasing of drain spacingngasing of drain spacingng spacingng

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A Paired Barrel Capable of Automatic Storage and Emptying of Water for a Weighing Raingauge (자동 저수와 배수가 가능한 중량 우량계 용 쌍수조)

  • Lim, Gyu-Ho;Lim, Eun Ok
    • Atmosphere
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    • v.27 no.2
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    • pp.251-258
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    • 2017
  • The standard weighing raingauges have a capacity limit in measuring the amounts of precipitation. Exceptions are those using a siphon to drain the collected water during observations. To reduce the drain time of the siphon type or to overcome the hassles associated with the manual emptying of the bucket for measuring, the most of weighing gauges use a large bucket for storing of rainwater to be measured. To avoid the above-mentioned adverse requirements, we propose a paired barrel for a weighing raingauge. The paired barrel may improve the accuracy of the weighing raingauges by getting rid of their capacity limit and make the gauges smaller in size and lighter in weight than the conventional ones. We showed its proper function and the feasibility of realization by testing a prototype paired barrel.

Application of Numerical Analysis for Sand Drain by the Multi-purpose Program of Soft Foundation Analysis (연약식반교양공법에 이용될 범용프로그램의 Sand Drain 공법에의 적용)

  • 박병기;정진섭
    • Geotechnical Engineering
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    • v.1 no.2
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    • pp.17-26
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    • 1985
  • This study was carried out for the purpose of comparing in reference to sand drain in the next three different cases. First, The case of drain material (sand pile) has some rigidity during embankment and consolidation. Second, In usual case of no rigidity as a paper drain without permeability during embankment and consolidation Third, Check up clay behavior when above the two cases carried out respectively. This FEM analysis is consisted with Biot's consolidation equation when it is used for Christian Boehmer's numerical technique. The main results are obtained from above the Analysis When sand drain has some rigidity, the lateral and vertical deformation of clay foundation is restrained considerable amount and .exhibited bearing capacity of load as a pile According to the foundation in drained condition and untrained condition, the results are much variable in this analysis method. Also, The behaviors of stress path and pore water pressure met our expectation during , consolidation. This analysis should be considered to put into use of sand drain and design in future.

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An Analysis about Inundation and Carrying Capacity of Drain Pipes in Urban Area (도시유역의 우수관거 통수능 및 침수특성 분석)

  • Lee, Jung-Ho;Jo, Duk-Jun;Kim, Joong-Hoon;Kim, Eung-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.1
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    • pp.110-115
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    • 2007
  • The localized rainfall happens frequently in urban areas recently and then, he drain pipes of urban areas do not drain well when the localized rainfalls happen. Specially, the inundation by the backwater on the lowland should be solved certainly in urban planning and sewer rehabilitation. In this study, it was examined whether the carrying capacities of the drain pipe are satisfied about a current design standard of the rainfall considering the outflows of the urban areas by the rainfall analysis. Also, the backwater in the drain pipe and the inundation on the lowland were analyzed considering the water level of the discharged river and the propriety of the design standard was examined by the analysis about the rainfall frequency. Also, the results offered the basic data to decide whether the detention reservoir should be established and the scale of the pump station.

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Reliability-Based Design of Vertical Drain Method Considering Uncertainties in Geotechnical Property (연약지반의 불확실성을 고려한 연직배수공법의 신뢰성 설계)

  • Kim, Byung-Il;Sah, Sang-Ho;Kim, Bang-Sig;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1148-1154
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    • 2006
  • Composite discharge capacity tests and smear effect tests are carried out to estimate the parameters for the reliability-based design of vertical drain method. Also the probabilistic and deterministic solutions of radial consolidation theory are presented. It compared to the result of reliability-based design and that of deterministic design using the tested and estimated parameters. The results indicated that the drain spacing is larger the deterministic method than the probabilistic method because the former is not considered the uncertainties in the properties of soil. The divergence of methods is dependent on the probability of achieving target degree of consolidation by a given time and the coefficient of variation(COV) of the coefficient of horizontal consolidation$(c_h)$.

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Effect of Loading Rate to Bearing Capacities (지지력에 미치는 재하속도에 관한 해석적 연구)

  • 박중배
    • Geotechnical Engineering
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    • v.13 no.1
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    • pp.147-158
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    • 1997
  • In this study, it is examined that partial drain has an effect of bearing capacities and deformations on intermediate soils. To compare the numerical and experimental results, this study uses CRISP90 which is composed of Modify Cam-Clay Model for calculation and Geotechnical Centrifuge in model test. As the results of analysis, we can classify relative loading rate into three ranges which are drain, undrain and partial drain. Besides it is proved that partial drain range is about 103.

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