• Title/Summary/Keyword: 1/4 scale model

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ANALYSIS OF NON-POINT SOURCE POLLUTION LOADING IN A SMALL RURAL WATERSHED USING HIGH SPATIAL RESOLUTION IMAGE

  • Park, Jong-Yoon;Lee, Mi-Seon;Kim, Seong-Joon
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.229-233
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    • 2007
  • This study is to test the applicability of QuickBird image for non-point source pollution assessment. SWAT (Soil and Water Assessment Tool) model was adopted and the model was calibrated for a stream watershed of 255.4 $km^2$ Landsat land use data. For model application with QuickBird image, a precise agricultural land use map of 1.16 $km^2$ area located in the upstream watershed was produced by field investigation. The model was run with the combination of land use and soil map scales (1:5,000, 1:25,000 and 1:50,000). The results were compared and analyzed for the contribution of non-point source pollution by the land use scale and contents.

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A Study on Lateral Distribution of Implanted Ions in Silicon

  • Jung, Won-Chae;Kim, Hyung-Min
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.4
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    • pp.173-179
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    • 2006
  • Due to the limitations of the channel length, the lateral spread for two-dimensional impurity distributions is critical for the analysis of devices including the integrated complementary metal oxide semiconductor (CMOS) circuits and high frequency semiconductor devices. The developed codes were then compared with the two-dimensional implanted profiles measured by transmission electron microscope (TEM) as well as simulated by a commercial TSUPREM4 for verification purposes. The measured two-dimensional TEM data obtained by chemical etching-method was consistent with the results of the developed analytical model, and it seemed to be more accurate than the results attained by a commercial TSUPREM4. The developed codes can be applied on a wider energy range $(1KeV{\sim}30MeV)$ than a commercial TSUPREM4 of which the maximum energy range cannot exceed 1MeV for the limited doping elements. Moreover, it is not only limited to diffusion process but also can be applied to implantation due to the sloped and nano scale structure of the mask.

A modified shell-joint model for segmental tunnel dislocations under differential settlement

  • Jianguo Liu;Xiaohui Zhang;Yuyin Jin;Wenyuan Wang
    • Geomechanics and Engineering
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    • v.35 no.4
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    • pp.411-424
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    • 2023
  • Reasonable estimates of tunnel lining dislocations in the operation stage, especially under longitudinal differential settlement, are important for the design of waterproof gaskets. In this paper, a modified shell-joint model is proposed to calculate shield tunnel dislocations under longitudinal differential settlement, with the ability to consider the nonlinear shear stiffness of the joint. In the case of shell elements in the model, an elastoplastic damage constitutive model was adopted to describe the nonlinear stress-strain relationship of concrete. After verifying its applicability and correctness against a full-scale tunnel test and a joint shear test, the proposed model was used to analyze the dislocation behaviors of a shield tunnel in Shanghai Metro Line 2 under longitudinal differential settlement. Based on the results, when the tunnel structure is solely subjected to water-earth load, circumferential and longitudinal joint dislocations are all less than 0.1 mm. When the tunnel suffers longitudinal differential settlement and the curvature radius of the differential settlement is less than 300 m, although maximum longitudinal joint dislocation is still less than 0.1 mm, the maximum circumferential joint dislocation is approximately 10.3 mm, which leads to leakage and damage of the tunnel structure. However, with concavo-convex tenons applied to circumferential joints, the maximum dislocation value reduces to 4.5 mm.

Family Function and Successful Aging for Vulnerable Elderly Based on Circumplex Model (Circumplex Model에 근거한 취약가구 노인의 가족기능과 성공적 노화)

  • Park, Jee-Won;Ban, Keum-Ok
    • Korean Journal of Adult Nursing
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    • v.22 no.3
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    • pp.239-249
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    • 2010
  • Purpose: The objective of this study was to identify the relationships between family function and successful aging of vulnerable elderly using the circumplex model. Methods: The participants were the elderly (N=401) who were over 65 years old living in H city under the National Livelihood Security Act. Family Adaptability and Cohesion Evaluation Scale III and Successful Aging Instrument were used. Results: The family function perceived by the study subjects was average $43.20{\pm}16.62$ out of maximum 100 points. According to the analysis on family types suggested by circumplex model, there were 183 people for balance family (45.6%) and 218 people (54.4%) for extreme family. The total points on successful aging were $1.67{\pm}0.37$ out of 3 points. When the difference in points on the Successful Aging instrument were analyzed according to the scores on the Family Adaptability and Cohesion Scale those points of the balanced family were statistically significant (t=2.087, p=.038). Conclusion: In case of the balanced family type, the level of perceiving successful aging was relatively higher. For the improvement of family function, it is advised that the successful aging perception among vulnerable elderly can be uplifted through a program that enables effective communication with other family members.

Occupational Health Care Management Model in Small Scale Enterprises (소규모 사업장 보건관리 모델개발에 관한 연구)

  • Yun, Soon-Nyung;Jung, Hye-Sun
    • Research in Community and Public Health Nursing
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    • v.12 no.3
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    • pp.647-660
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    • 2001
  • Forming health care management model in small-scale enterprises was the purpose of this study. For the purpose, we tried to investigate the characteristics of small-scale enterprises and analyzed the pattern of their health care management. The results are as follow: 1. The strength of health managing agency and technical supporting program lies in team approach by specialized manpower. However, if the liaison between each part of the organization is not smooth, the overall management will be very difficult. 2. Small scale enterprises are characterized by their short life after the establishment, use of rental building, lack of welfare facilities, weakness in sanitary management and aggregation of factories of similar type of industry. Because of these characteristics, it is very difficult to solve problem basically, such as improvement of working environment. Therefore, it is important to focus on health education and community based approach. 3. Many workers in small-scale factories are in middle and old age. They have health problems mainly related to personal habits. Implementation of an appropriate health promotion program is needed. 4. The number of workplaces, which should be managed by health managing agent. is increasing rapidly. But the number of health managing agent is limited. In the aspect of the requirement of manpower and equipment, training personal agent is more urgent than founding institutional agent. 5. The uniform method of health management hampers the choice of employer and workers. The types of provision of health management should be diversified. 6. For an efficient management, a frequent visit of personal agent and the following referral to a specialist should be done. The specialists in charge of secondary management are from the field of occupational medicine, occupational hygiene, ergonomics, etc. 7. The health management of small-scale facilities should have six components. They are community-based approach, multi-disciplinary cooperative system, program based on the need of recipient, forming partnership of employer and worker, change of lifestyle, and evidence-based program.

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Analytical modeling of masonry infills with openings

  • Kakaletsis, D.
    • Structural Engineering and Mechanics
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    • v.31 no.4
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    • pp.423-437
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    • 2009
  • In order to perform a step-by-step force-displacement response analysis or dynamic time-history analysis of large buildings with masonry infilled R/C frames, a continuous force-deformation model based on an equivalent strut approach is proposed for masonry infill panels containing openings. The model, which is applicable for degrading elements, can be implemented to replicate a wide range of monotonic force-displacement behaviour, resulting from different design and geometry, by varying the control parameters of the model. The control parameters of the proposed continuous model are determined using experimental data. The experimental program includes fifteen 1/3-scale, single-story, single-bay reinforced concrete frame specimens subjected to lateral cyclic loading. The parameters investigated include the shape, the size, the location of the opening and the infill compressive strength. The actual properties of the infill and henceforth the characteristics needed for the diagonal strut model are based on the assessment of its lateral resistance by the subtraction of the response of the bare frame from the response of the infilled frame.

Numerical Study on Turbulent Flow Inside a Channel with an Extended Chamber (난류 경계층에 놓인 공동 내부유동에 관한 수치해석적 연구)

  • Lee, Young-Tae;Lim, Hee-Chang
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.10
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    • pp.925-931
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    • 2010
  • The paper describes a Large Eddy Simulation (LES) study of turbulent flow around a cavity. A series of three-dimensional cavities placed in a turbulent boundary layer are simulated at a Reynolds number of $1.0{\times}10^5$ by considering U and h, which represent the velocity at the top and the depth of the cavity, respectively. In order to obtain the appropriate solution for the filtered Navier-Stokes equation for incompressible flow, the computational mesh forms dense close to the wall of the cavity but relatively coarse away from the wall; this helps reduce computation cost and ensure rapid convergence. The Boussinesq hypothesis is employed in the subgrid-scale turbulence model. In order to determine the subgrid-scale turbulent viscosity, the Smagorinsky-Lilly SGS model is applied and the CFL number for time marching is set as 1.0. The results show the flow variations inside cavities of different sizes and shapes.

PDFindexer: Distributed PDF Indexing system using MapReduce

  • Murtazaev, JAziz;Kihm, Jang-Su;Oh, Sangyoon
    • International Journal of Internet, Broadcasting and Communication
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    • v.4 no.1
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    • pp.13-17
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    • 2012
  • Indexing allows converting raw document collection into easily searchable representation. Web searching by Google or Yahoo provides subsecond response time which is made possible by efficient indexing of web-pages over the entire Web. Indexing process gets challenging when the scale gets bigger. Parallel techniques, such as MapReduce framework can assist in efficient large-scale indexing process. In this paper we propose PDFindexer, system for indexing scientific papers in PDF using MapReduce programming model. Unlike Web search engines, our target domain is scientific papers, which has pre-defined structure, such as title, abstract, sections, references. Our proposed system enables parsing scientific papers in PDF recreating their structure and performing efficient distributed indexing with MapReduce framework in a cluster of nodes. We provide the overview of the system, their components and interactions among them. We discuss some issues related with the design of the system and usage of MapReduce in parsing and indexing of large document collection.

Mechanical Properties of Hydrated Cement Paste: Development of Structure-property Relationships

  • Ghebrab, Tewodros T.;Soroushian, Parviz
    • International Journal of Concrete Structures and Materials
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    • v.4 no.1
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    • pp.37-43
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    • 2010
  • Theoretical models based on modern interpretations of the morphology and interactions of cement hydration products are developed for prediction of the mechanical properties of hydrated cement paste (hcp). The models are based on the emerging nanostructural vision of calcium silicate hydrate (C-S-H) morphology, and account for the intermolecular interactions between nano-scale calcium C-S-H particles. The models also incorporate the effects of capillary porosity and microcracking within hydrated cement paste. The intrinsic modulus of elasticity and tensile strength of hydrated cement paste are determined based on intermolecular interactions between C-S-H nano-particles. Modeling of fracture toughness indicates that frictional pull-out of the micro-scale calcium hydroxide (CH) platelets makes major contributions to the fracture energy of hcp. A tensile strength model was developed for hcp based on the linear elastic fracture mechanics theories. The predicted theoretical models are in reasonable agreements with empirical models developed based on the experimental performance of hcp.

Shaking Table Test of 1/3-Scale 3-Story Sam-Hwan Camus Precast Concrete Model (1/3축소 3층 삼환까뮤 P.C 모델의 진동대 실험)

  • 이한선
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.10a
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    • pp.140-154
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    • 1992
  • The objective of the research stated here was aimed at providing the information needed to establish the Korean Seismic Design Code Recommendations and Guides for precast concrete (P.C) large panel apartment buildings. This was accomplished by investigation and analysis of the response of P.C large panel structures subjected to shaking table excitation simulating earthquake ground motion. one of the test specimens used was 1/3-scaled 3-story box P.C model provided by Sam-Hwan Camus Corporation. The 4m $\times$4m shaking table was used to simulate the earthquake ground motion. the employed input accelerogram was the one recorded as Taft N21E component and the peak ground acceleration(PGA) was scaled depending on the desired level of seismic severity and the time according to dynamic similitude rule. Based on results obtained from shaking table test of this P.C model, the following conclusions were drawn . (1) As far as test specimen is concerned, the seismic safety factors turns out to be 7~8. (2)P.C model has damping ratio of about8% which is twice larger than in-situ R.C. structure. And (3)this model has global displacement ductility ratio of 2~3 through the energy dissipation by opening and sliding of joints.

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