• Title/Summary/Keyword: Distributed-Element

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Implementation of Massive FDTD Simulation Computing Model Based on MPI Cluster for Semi-conductor Process (반도체 검증을 위한 MPI 기반 클러스터에서의 대용량 FDTD 시뮬레이션 연산환경 구축)

  • Lee, Seung-Il;Kim, Yeon-Il;Lee, Sang-Gil;Lee, Cheol-Hoon
    • The Journal of the Korea Contents Association
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    • v.15 no.9
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    • pp.21-28
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    • 2015
  • In the semi-conductor process, a simulation process is performed to detect defects by analyzing the behavior of the impurity through the physical quantity calculation of the inner element. In order to perform the simulation, Finite-Difference Time-Domain(FDTD) algorithm is used. The improvement of semiconductor which is composed of nanoscale elements, the size of simulation is getting bigger. Problems that a processor such as CPU or GPU cannot perform the simulation due to the massive size of matrix or a computer consist of multiple processors cannot handle a massive FDTD may come up. For those problems, studies are performed with parallel/distributed computing. However, in the past, only single type of processor was used. In GPU's case, it performs fast, but at the same time, it has limited memory. On the other hand, in CPU, it performs slower than that of GPU. To solve the problem, we implemented a computing model that can handle any FDTD simulation regardless of size on the cluster which consist of heterogeneous processors. We tested the simulation on processors using MPI libraries which is based on 'point to point' communication and verified that it operates correctly regardless of the number of node and type. Also, we analyzed the performance by measuring the total execution time and specific time for the simulation on each test.

Effects of Service Quality including Food Therapy Element on Positive Emotion and Brand loyalty: Focusing on Daegu-Gyeongbuk Hansik Buffet Restaurant Customers (푸드테라피와 서비스품질이 긍정적 감정 및 브랜드충성도에 미치는 영향: 대구·경북지역 한식뷔페레스토랑 고객을 중심으로)

  • Lee, Ji-Yun;Byun, Gwang-In
    • The Journal of the Korea Contents Association
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    • v.18 no.10
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    • pp.464-477
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    • 2018
  • This study is effect of food therapy and service quality, aimed to examine the relationship between positive emotion and brand loyalty. It examined the effects of service quality and food therapy on positive emotion, and examined the effects of positive emotion on brand loyalty, and then aimed to examine the indirect effects of service quality and food therapy on brand loyalty. To this end, quota sampling was conducted according to the job ratio of the customers visiting Hansik buffet restaurants. A survey was carried out from July 1 to 25, 2018(25 days), and a total of 850 questionnaires were distributed and 786 of collected 805 questionnaires were finally used for an analysis excluding 19 unreliable ones. The results of analysis were as follows: food quality, service encounter, physical therapy and psychological therapy significantly affected positive emotion, while service environment was not significant. Also, positive emotion significantly affected brand loyalty, and food quality, service encounter, physical therapy, psychological therapy had significant indirect effects on brand loyalty. The present study is significant in the aspect that it determined how important a role food therapy elements play in improving brand loyalty in a restaurant-related study.

Pollution Status of Surface Sediment in Jinju Bay, a Spraying Shellfish Farming Area, Korea (살포식 패류양식해역인 진주만 표층 퇴적물의 오염도)

  • Lee, Garam;Hwang, Hyunjin;Kim, Jeong Bae;Hwang, Dong-Woon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.4
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    • pp.392-402
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    • 2020
  • We investigated the concentrations of acid volatile sulfide (AVS), ignition loss (IL), total organic carbon (TOC), total nitrogen (TN), and metallic elements (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn), in August 2015, to determine the spatial distribution and pollution status of organic matter and metals in the surface sediment of Jinju Bay, a spraying shellfish farming area, Korea. The concentrations of organic matter and metallic elements were significantly higher in the southern part of the bay than in the mouth and center of the bay. The C/N ratio (5.7~8.0) in the sediment represents the dominance of organic matter of oceanic origin in the surface sediment of the study area. The concentrations of AVS, TOC, and metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) were much lower than the values of the sediment quality guidelines applied in Korea. Based on the results of the pollution load index (PLI) and ecological risk index (ERI), the metal concentrations in the surface sediment of Jinju Bay have a weakly negative ecological effect on benthic organisms although the sediments with high metal pollution status are distributed in the southern parts of the bay, with high dense shellfish farming areas. Thus, the surface sediments in Jinju Bay are not polluted with organic matter and are slightly polluted with metallic elements.

A Study on Inelastic Lateral-Torsional Buckling of Stepped I-Beams Subjected to Pure Bending (균일모멘트를 받는 계단식 I형보의 비탄성 횡-비틀림 좌굴에 관한 연구)

  • Kim, Jong Min;Kim, Seung Jun;Park, Jong Sup;Kang, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.20 no.2
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    • pp.237-246
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    • 2008
  • The cross-sections of continuous multi-span beams sometimes suddenly increase, or become stepped, at the interior supports of continuous beams to resist high negative moments. The three-dimensional finite-element program ABAQUS (2006) was used to analytically investigate the inelastic lateral-torsional buckling behavior of stepped beams subjected to pure bending moment and resulted in the development of design equations. The flanges of the smaller cross-section were fixed at 30.48 by 2.54 cm, whereas the width and/or thickness of the flanges of the larger cross-section varied. The web thickness and height of beam was kept at 1.65 cm and 88.9 cm, respectively. The ratios of the flange thickness, flange width, and stepped length of beams are considered analytical parameters. Two groups of 27 cases and 35 cases, respectively, were analyzed for double and single stepped beams. The combined effects of residual stresses and geometrical imperfection on inelastic lateral-torsional buckling of beams are considered. First, the distributions of residual stress of the cross-section is same as shown in Pi, etc (1995), and the initial geometric imperfection of the beam is set by central displacement equal to 0.1% of the unbraced length of beam. The new proposed equations definitely improve current design methods for the inelastic LTB problem and increase efficiency in building and bridge design. The proposed solutions can be easily used to develop new design equation for inelastic LTB resistance of stepped beams subjected to general loading condition such as a concentrated load, a series of concentrated loads or uniformly distributed load.

An Embedded System Design of Collusion Attack Prevention for Multimedia Content Protection on Ubiquitous Network Environment (유비쿼터스 네트워크 환경의 멀티미디어 콘텐츠 보호를 위한 공모공격 방지 임베디드 시스템 설계)

  • Rhee, Kang-Hyeon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.1
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    • pp.15-21
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    • 2010
  • This paper proposes the multimedia fingerprinting code insertion algorithm when video content is distributed in P2P environment, and designs the collusion codebook SRP(Small RISC Processor) embedded system for the collusion attack prevention. In the implemented system, it is detecting the fingerprinting code inserted in the video content of the client user in which it requests an upload to the web server and in which if it is certified content then transmitted to the streaming server then the implemented system allowed to distribute in P2P network. On the contrary, if it detects the collusion code, than the implemented system blocks to transmit the video content to the streaming server and discontinues to distribute in P2P network. And also it traces the colluders who generate the collusion code and participates in the collusion attack. The collusion code of the averaging attack is generated with 10% of BIBD code v. Based on the generated collusion code, the codebook is designed. As a result, when the insert quantity of the fingerprinting code is 0.15% upper in bitplane 0~3 of the Y(luminance) element of I-frame at the video compression of ASF for a streaming service and MP4 for an offline offer of video content, the correlation coefficient of the inserted original code and the detected code is above 0.15. At the correlation coefficient is above 0.1 then the detection ratio of the collusion code is 38%, and is above 0.2 then the trace ratio of the colluder is 20%.

Analysis of Fault Attitudes by Using Trajectories of the Maximum Longitudinal Displacement on Tunnel Face (터널 굴진면 최대 수평변위의 변화 양상에 따른 단층 자세 분석)

  • Yun, Hyun-Seok;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.26 no.3
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    • pp.393-401
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    • 2016
  • In the present study, fault attitudes and the locations of appearance of faults in tunnel faces were predicted by analyzing the trajectory of the maximum longitudinal displacement immediately before the appearance of faults through three-dimensional finite element analysis. A total of 28 fault attitude models were used in the analysis. Those faults that have drives with dip appear first in the upper part of tunnel faces as tunnel excavation progresses and their maximum longitudinal displacement shows a tendency to move from the middle part to the upper part of tunnel faces. Those faults that have drives against dip appear first in the lower part of tunnel faces as tunnel excavation progresses and their maximum longitudinal displacement shows a tendency to move from the middle part or middle upper part to the lower part of tunnel faces. In addition, when the dip of faults is larger the maximum longitudinal displacement moves from the left upper part toward the wall part in the case of drive with dip models and from the left lower part toward the wall part in the case of drives against dip models. Therefore, it was indicated that the attitudes of faults distributed ahead of tunnel faces and the locations where faults appear in tunnel faces can be predicted by analyzing the longitudinal displacement trajectory of tunnel faces following excavation.

Influence of Self-Differentiation and Acculturation on Marriage Satisfaction Among Immigrant Women by Residential Area (거주지역에 따른 결혼이민자 여성의 자아분화 및 문화적응이 결혼만족도에 미치는 영향)

  • Lee, Young-Boon;Lee, Yu-Kyung
    • Journal of Families and Better Life
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    • v.28 no.1
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    • pp.145-157
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    • 2010
  • This is a study that explores the influence of self-differentiation and acculturation among married immigrant women on their feelings of marriage satisfaction by residential area. The aim was to verify the level of self-differentiation and acculturation that married immigrant women secure from multicultural marriage. To achieve this objective, the study widely distributed a questionnaire that targeted women who were participating in education and other services at health and family support centers, multi-cultural family support centers, general social welfare centers, immigrant women shelters, and Korean language classrooms which are located in Seoul, Gyeonggi, Chungcheong, Jeolla, and Gyeongsang. Data analysis involved frequency analysis, descriptive statistics, one-way-Anova, and multiple regression analysis. Based on the results of descriptive statistics, two factors, namely, (1)interpersonal-relation differentiation, a sub-scale of self-differentiation, and (2)marginalization, a sub-scale of acculturation, had the lowest average. In verifying its various hypotheses, the study achieved the following results. Firstly, among demographic characteristics, there was difference of the mean in the marriage period, average monthly income, the frequency of meetings with the married woman´s parents-in-law and her own parents, and the average cost of supporting the woman's parents-in-law and her own parents. Secondly, among demographic characteristics, the variable of influencing marriage satisfaction showed negative influence in the case of women dwelling in farming and fishing villages. This shows that women residing in cities whether small, medium or large have higher marriage satisfaction. Also, as a result of verifying whether self-differentiation has influence on marriage satisfaction, the element of interpersonal-relations differentiation had a negative influence on marriage satisfaction. Thirdly, as for influence of acculturation upon marriage satisfaction, the study showed that just integration, which is a sub-scale of acculturation had positive effect on marriage satisfaction. In other words, the study showed that the interpersonal-relation differentiation among the sub-scales of self-differentiation among married immigrant women had a negative influence, and that integration among the sub-scales in acculturation had a positive influence on marriage satisfaction. Based on these results, in order to increase interpersonal-relation differentiation, as well as marriage satisfaction among immigrant women, the study suggests the integration of the women's families with the nuclear and extended families in the communities where the women reside.

Characteristics of Ti-SPAC as Fluidizing Phase Photocatalyst (Ti-구형활성탄의 유동상 광촉매 특성 평가)

  • Lee, Joon-Jae;Suh, Jeong-Kwon;Hong, Ji-Sook;Park, Jin-Won;Lee, Jung-Min
    • Korean Chemical Engineering Research
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    • v.44 no.4
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    • pp.375-381
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    • 2006
  • In this sturdy, spherical activated carbon(SPAC) contained $TiO_2$ was made by ion-exchanged treatment and heat treatment for applying fluidizing bed system. The ion-exchange resin was treated by $TiCl_3$ aqueous solution. The treated resin and raw resin were heat-treated under nitrogen condition to convert into Ti-SPAC. During the heat-treatment, burn-off weight amounts and the element were measured by means of TGA and TGA/MS, individually. The physicochemical properties of Ti-SPAC was characterized by means of XRD, SEM, EDS, BET, EPMA, ESR, intensity and titanium content. The Ti-SPAC had spherical shape with diameter size about $350{\mu}m{\sim}400{\mu}m$ and $617m^2/g$ specific surface area. Structure of $TiO_2$ in Ti-SPAC was anatase and rutile form. Also, $TiO_2$ on SPAC were found that the $TiO_2$ were uniformly distributed through EPMA analysis. Moreover, the Ti-SPAC showed indirect photocatalyst activity estimation through ESR analysis, characteristics of photocatalyst potentially. Over all results, Ti-SPAC was used in fluidizing bed UV/photocatalyst system to remove HA(Humic Acid). That results were HA removal efficiency was about 70% and Ti-SPAC intensity was preserved during reaction. Ti-SPAC showed practical possibility as photocatalyst in fluidizing bed system.

Groundwater Flow Model for the Pollutant Transport in Subsurface Porous Media Theory and Modeling (지하다공질(地下多孔質) 매체(媒體)속에서의 오염물질이동(汚染物質移動) 해석(解析)을 위한 지하수(地下水)흐름 모형(模型))

  • Cho, Won Cheal
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.3
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    • pp.97-106
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    • 1989
  • This paper is on the modeling of two-dimensional groundwater flow, which is the first step of the development of Dynamic System Model for groundwater flow and pollutant transport in subsurface porous media. The particular features of the model are its versatility and flexibility to deal with as many real-world problems as possible. Points as well as distributed sources/sinks are included to represent recharges/pumping and rainfall infiltrations. All sources/sinks can be transient or steady state. Prescribed hydraulic head on the Dirichlet boundaries and fluxes on Neumann or Cauchy boundaries can be time-dependent or constant. Sources/sinks strength over each element and node, hydraulic head at each Dirichlet boundary node and flux at each boundary segment can vary independently of each other. Either completely confined or completely unconfined aquifers, or partially confined and partially unconfined aquifers can be dealt with effectively. Discretization of a compound region with very irregular curved boundaries is made easy by including both quadrilateral and triangular elements in the formulation. Large-field problems can be solved efficiently by including a pointwise iterative solution strategy as an optional alternative to the direct elimination solution methed for the matrix equation approximating the partial differential equation of groundwater flow. The model also includes transient flow through confining leaky aquifers lying above and/or below the aquifer of interest. The model is verified against three simple cases to which analytical solutions are available. The groundwater flow model shall be combined with the model of pollutant transport in subsurface porous media. Then the combined model, with the applications of the Eigenvalue technique and the Dynamic system theory, shall be improved to the Dynamic System Model which can simulate the real groundwater flow and the pollutant transport accurately and effectively for the analyses and predictions.

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The Analysis of Elasto-Plastic Thermal Stresses for Welding Part in Double Capstan Drum (더블 캡스턴 드럼의 용접부에 대한 탄소성 열응력해석)

  • 김옥삼
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.4
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    • pp.329-336
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    • 2000
  • Welding is a important technological method in mechanical engineering. $CO_2$MAG(metal active gas) welding means that metal part in double capstan drum for the inshore and costal vessels are joined by melting(with or without a filler material) or that new material is added to a metal part by melting. The thermal stresses appear due to a non-uniform temperature field, inhomogeneous material properties, external restraint and volume changes during phase transformations. In this study analysis the elasto-plastic thermal stresses distribution of welding part in double capstan drum for the inshore and costal vessels using finite element method (FBM). Therefore it calculates the numerical value that can be applied to the optimum design of welding parts and the shapes. The significant results obtained in this study are summarized as fellows. At early stage of the cooling after welding process, the abrupt thermal stresses gradient has been shown in the vicinity of welding part. In the thermal stresses analysis due to temperature gradient and heat shocking maximum stress was occurred of welding part and stresses were distributed from 54MPa~48MPa.

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