• Title/Summary/Keyword: Media Flow

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Fracture and Hygrothermal Effects in Composite Materials (복합재의 파괴와 hygrothermal 효과에 관한 연구)

  • Kook-Chan Ahn;Nam-Kyung Kim
    • Journal of the Korean Society of Safety
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    • v.11 no.4
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    • pp.143-150
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    • 1996
  • This is an explicit-Implicit, finite element analysis for linear as well as nonlinear hygrothermal stress problems. Additional features, such as moisture diffusion equation, crack element and virtual crack extension(VCE ) method for evaluating J-integral are implemented in this program. The Linear Elastic Fracture Mechanics(LEFM) Theory is employed to estimate the crack driving force under the transient condition for and existing crack. Pores in materials are assumed to be saturated with moisture in the liquid form at the room temperature, which may vaporize as the temperature increases. The vaporization effects on the crack driving force are also studied. The Ideal gas equation is employed to estimate the thermodynamic pressure due to vaporization at each time step after solving basic nodal values. A set of field equations governing the time dependent response of porous media are derived from balance laws based on the mixture theory Darcy's law Is assumed for the fluid flow through the porous media. Perzyna's viscoplastic model incorporating the Von-Mises yield criterion are implemented. The Green-Naghdi stress rate is used for the invariant of stress tensor under superposed rigid body motion. Isotropic elements are used for the spatial discretization and an iterative scheme based on the full newton-Raphson method is used for solving the nonlinear governing equations.

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A Study on the Analysis of Current Issues and the Operation Plan of News Media Asset Management System in Korean Broadcasting Companies: the Case Study of KBS Digital Newsroom (방송사 보도영상관리시스템 운영 현황분석과 개선안 연구 - KBS 디지털뉴스룸 사례를 중심으로 -)

  • Choi, Hyo-jin;Park, Choonwon;Kim, Sooyoung;Song, Jeonga;Park, Yeajin;Shin, Bongseung;Ji, Sunho;Sun, Sangwon
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.33 no.3
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    • pp.123-155
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    • 2022
  • This study focuses on the management of the news production system in broadcasting companies. This paper concentrates on the process of data registration and metadata management in order to examine whether the currently produced news can have value as a 'public record' in the long term, and whether reliable and accurate information is preserved. In addition, the user experience in the current system is analyzed through in-depth interviews with Ingest Managers, Editors, and Archive Managers, who are closely related to metadata creation compared to other members of the its News Department. Finally, a sustainable metadata quality management method is sought to increase the value of news footage as a 'public record'. In this study, these points can be found out: the metadata of the news agency footage is input manually according to the user's will or working style, that is, the user-friendly metadata input system is insufficient. Accordingly, it can be seen that the quality of the metadata of the news video continues to deteriorate. As an alternative to overcome this, it is found that work flow improvement, system improvement, classification system and metadata improvement plan, etc. are definitely necessary in the short and long term.

A Study on the Effects of Teacher Librarians' Media and Information Literacy Classes: Focused on the High School Credit System (사서교사의 미디어 정보 리터러시 수업 효과에 관한 연구 - 고교학점제를 중심으로 -)

  • Bong-Suk Kang;Juhyeon Park
    • Journal of the Korean Society for Library and Information Science
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    • v.57 no.2
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    • pp.179-198
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    • 2023
  • The purpose of this study is to verify the role of teacher librarians by examining the cases of media and information literacy(MIL) classes in the joint curriculum of high school credit system research school. The classes were two 34th classes joint curriculum established by two teacher librarians at the high school credit system research school. Individual students set their own inquiry problems integrated with their careers or subjects, and teacher librarians guide the process of solving them based on the process of using MIL. The participants were 22 high school students in Daegu who filled out the questionnaire before and after completing the course. The effect of the classes was analyzed through a questionnaire consisting of 42 questions for the 3 factors of access, evaluation, and creation, which are the components of MIL announced by UNESCO. As a result, all 3 factors and 25 of the sub-42 survey items showed a statistically significant difference before and after class, It was investigated that literacy of students improved through MIL education of teacher librarians. Through this study, it will be possible to expand the awareness of the effect of the educational role of teacher librarians in the flow of future curriculum.

Design of Collaborative Production & Supply Planning System based on ebXML (신발산업의 협업적 생산 및 공급계획시스템 설계)

  • Choi, Hyung-Rim;Hyun, Seung-Yong;Lim, Ho-Seob;Yoo, Dong-Yeol
    • Information Systems Review
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    • v.8 no.1
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    • pp.1-24
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    • 2006
  • Now, the Korean footwear industry needs the concrete enhancement of its competitive edge for regaining of its previous well known reputation. For this purpose, this study emphasizes the cooperation between the members through the supply chain of Korean footwear industry, as a c-SCM(Collaborative Supply Chain Management) by aid of information system. The key issue will be how well to coordinate operations flow not only through internal process stages, but also through entire external supply chain stages. In other words, the target goal must be the system optimization through the entire supply chain beyond the local optimization of internal supply chain process. We, at first, analyze the traditional structure of supply chain in Korean footwear industry and find out critical problems, and then, we develop the collaborative information framework in conjunction with several collaborative process modules. The suggested collaborative production & supply planning system was designed for sharing information and it is based on ebXML(electronic business eXtensible Markup Language) framework. In this way, the enhancement of the efficiency and competitiveness can be expected through the synergy effect of coordination of information and material flow, the reduction of lead times, and production costs.

A Study on the Constructing Discrete Fracture Network in Fractured-Porous Medium with Rectangular Grid (사각 격자를 이용한 단열-다공암반내 분리 단열망 구축기법에 대한 연구)

  • Han, Ji-Woong;Hwang, Yong-Soo;Kang, Chul-Hyung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.1
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    • pp.9-15
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    • 2006
  • For the accurate safety assessment of potential radioactive waste disposal site which is located in the crystalline rock it is important to simulate the mass transportation through engineered and natural barrier system precisely, characterized by porous and fractured media respectively. In this work the methods to construct discrete fracture network for the analysis of flow and mass transport through fractured-porous medium are described. The probability density function is adopted in generating fracture properties for the realistic representation of real fractured rock. In order to investigate the intersection between a porous and a fractured medium described by a 2 dimensional rectangular and a cuboid grid respectively, an additional imaginary fracture is adopted at the face of a porous medium intersected by a fracture. In order to construct large scale flow paths an effective method to find interconnected fractures and algorithms of swift detecting connectivities between fractures or porous medium and fractures are proposed. These methods are expected to contribute to the development of numerical program for the simulation of radioactive nuclide transport through fractured-porous medium from radioactive waste disposal site.

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Integrated Eco-Engineering Design for Sustainable Management of Fecal Sludge and Domestic Wastewater

  • Koottatep, Thammarat;Polprasert, Chongrak;Laugesen, Carsten H.
    • Journal of Wetlands Research
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    • v.9 no.1
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    • pp.69-78
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    • 2007
  • Constructed wetlands and other aquatic systems have been successfully used for waste and wastewater treatment in either temperate or tropical regions. To treat waste or wastewater in a sustainable manner, the integrated eco-engineering designs are explained in this paper with 2 case studies: (i) a combination of vertical-flow constructed wetland (CW) with plant irrigation systemfor fecal sludge management and (ii) integrated CW units with landscaping at full-scale application for domestic wastewater treatment. The pilot-scale study of fecal sludge management employed 3 vertical-flow CW units, each with a dimension of $5{\times}5{\times}0.65m$ (width ${\times}$ length ${\times}$ media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/$m^2.yr$ and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80 - 96%. The accumulated sludge layers of about 80 - 90 cm was found at the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation Sunflower plant (Helianthus annuus) plots, each with a dimension of $4.5{\times}4.5m$ ($width{\times}length$). In the study, the CW percolate were fed to the treatment plots at the application rate of 7.5 mm/day but the percolate was mixed with tap water at different ratio of 20%, 80% and 100%. Based on a 1-year data of 3-crop plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increasing in CW percolate ratios. The highest plant biomass yield and oil content of 1,000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower is found. In addition to the pilot-scale and field experiments, a case study of the integrated CW systems for wastewater treatment at Phi Phi Island (a Tsunami-hit area), Krabi province, Thailand is illustrated. The $5,200-m^2$ CW systems on Phi Phi Island are not only for treatment of $400m^3/day$ wastewater from hotels, households or other domestic activities, but also incorporating public consultation in the design processes, resulting in introducing the aesthetic landscaping as well as reusing of the treated effluent for irrigating green areas on the Island.

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Multi-view Image Generation from Stereoscopic Image Features and the Occlusion Region Extraction (가려짐 영역 검출 및 스테레오 영상 내의 특징들을 이용한 다시점 영상 생성)

  • Lee, Wang-Ro;Ko, Min-Soo;Um, Gi-Mun;Cheong, Won-Sik;Hur, Nam-Ho;Yoo, Ji-Sang
    • Journal of Broadcast Engineering
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    • v.17 no.5
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    • pp.838-850
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    • 2012
  • In this paper, we propose a novel algorithm that generates multi-view images by using various image features obtained from the given stereoscopic images. In the proposed algorithm, we first create an intensity gradient saliency map from the given stereo images. And then we calculate a block-based optical flow that represents the relative movement(disparity) of each block with certain size between left and right images. And we also obtain the disparities of feature points that are extracted by SIFT(scale-invariant We then create a disparity saliency map by combining these extracted disparity features. Disparity saliency map is refined through the occlusion detection and removal of false disparities. Thirdly, we extract straight line segments in order to minimize the distortion of straight lines during the image warping. Finally, we generate multi-view images by grid mesh-based image warping algorithm. Extracted image features are used as constraints during grid mesh-based image warping. The experimental results show that the proposed algorithm performs better than the conventional DIBR algorithm in terms of visual quality.

Understanding and predicting physical properties of rocks through pore-scale numerical simulations (공극스케일에서의 시뮬레이션을 통한 암석물성의 이해와 예측)

  • Keehm, Young-Seuk;Nur, Amos
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.201-206
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    • 2006
  • Earth sciences is undergoing a gradual but massive shift from description of the earth and earth systems, toward process modeling, simulation, and process visualization. This shift is very challenging because the underlying physical and chemical processes are often nonlinear and coupled. In addition, we are especially challenged when the processes take place in strongly heterogeneous systems. An example is two-phase fluid flow in rocks, which is a nonlinear, coupled and time-dependent problem and occurs in complex porous media. To understand and simulate these complex processes, the knowledge of underlying pore-scale processes is essential. This paper presents a new attempt to use pore-scale simulations for understanding physical properties of rocks. A rigorous pore-scale simulator requires three important traits: reliability, efficiency, and ability to handle complex microstructures. We use the Lattice-Boltzmann (LB) method for singleand two-phase flow properties, finite-element methods (FEM) for elastic and electrical properties of rocks. These rigorous pore-scale simulators can significantly complement the physical laboratory, with several distinct advantages: (1) rigorous prediction of the physical properties, (2) interrelations among the different rock properties in a given pore geometry, and (3) simulation of dynamic problems, which describe coupled, nonlinear, transient and complex behavior of Earth systems.

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Variation of facial temperature to 3D visual fatigue evoked (3D 시각피로 유발에 따른 안면 온도 변화)

  • Hwang, Sung Teac;Park, SangIn;Won, Myoung Ju;Whang, MinCheol
    • Science of Emotion and Sensibility
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    • v.16 no.4
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    • pp.509-516
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    • 2013
  • As the visual fatigue induced by 3D visual stimulation has raised some safety concerns in the industry, this study aims to quantify the visual fatigue through the means of measuring the facial temperature changes. Facial temperature was measured for one minute before and after watching a visual stimulus. Whether the visual fatigue has occurred was measured through subjective evaluations and high cognitive tasks. The difference in the changes that occurred after watching a 2D stimulus and a 3D stimulus was computed in order to associate the facial temperature changes and the visual fatigue induced by watching 3D contents. The results showed significant differences in the subjective evaluations and in the high cognitive tasks. Also, the ERP latency increased after watching 3D stimuli. There were significant differences in the maximum value of the temperature at the forehead and at the tip of the nose. A previous study showed that 3D visual fatigue activates the sympathetic nervous system. Activation of the sympathetic nervous system is known to increase the heart rate as well as the blood flow into the face through the carotid arteries system. When watching 2D or 3D stimuli, the sympathetic nervous system activation dictates the blood flow, which then influences the facial temperature. This study is meaningful in that it is one of the first investigations that looks into the possibility to measure 3D visual fatigue with thermal images.

Assessment of Hydrogeochemical Characteristics and Contaminant Dispersion of Aquifer around Keumsan Municipal Landfill (금산 매립장 주변 대수층의 수리지화학적 특성 및 오염 확산 평가)

  • Oh, In-Suk;Ko, Kyung-Seok;Kong, In-Chul;Ku, Min-Ho
    • Economic and Environmental Geology
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    • v.41 no.6
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    • pp.657-672
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    • 2008
  • The purposes of this study are to investigate the hydrogeochemical characteristics of groundwaters around Keumsan municipal landfill, and to evaluate the contaminant dispersion from the landfill and its environmental impact. To achieve these goals, groundwater quality logging, hydrochemical analysis, multivariate statistical analysis, and contaminant transport modeling were performed. The water quality logging indicated a leaking from the landfill at the depth of 4-12m around a leachate sump. Electrical conductivity data indicated that groundwaters within 70-100m from landfill were affected by the landfill leakage. Principal components 1 and 2 obtained from principal components analysis (PCA) reflect the influence of leachate and the characteristics of aquifer media, respectively. The results of principal component analysis also indicated the natural attenuation processes such as cation exchange, sorption, and microbial biodegradation. The modeling results showed that groundwater flow westward along a valley from the landfill and contaminants transport accordingly.