• Title/Summary/Keyword: hybrid model

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Modeling of the charge and discharge behavior of the 2S2P(2 series-2 parallel) AGM battery system for commercial vehicles (상용자동차용 직·병렬 AGM 배터리 시스템의 충·방전 거동 모델링)

  • Lee, Jeongbin;Kim, Ui Seong;Yi, Jae-Shin;Shin, Chee Burm
    • Journal of Energy Engineering
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    • v.21 no.4
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    • pp.346-355
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    • 2012
  • Recent in the world environmental issues and energy depletion problems have been received attention. One way to solve these problems is to use hybrid electric vehicles (HEVs). Therefore, the interest in HEV technology is higher than ever before. Viable candidates for the energy-storage systems in HEV applications may be absorbent glass mat (AGM) lead-acid, nickel-metal-hydride (Ni-MH) and rechargeable lithium batteries. The AGM battery has advantages in terms of relatively low cost, high charge efficiency, low self-discharge, low maintenance requirements and safety as compared to the other batteries. In order to implement HEV system in required more electric power commercial vehicles AGM batteries was connected to 2 series-2 parallels (2S2P). In this study, a one-dimensional modeling is carried-out to predict the behaviors of 2S2P AGM batteries system during charge and discharge. The model accounts for electrochemical reaction rates, charge conservation and mass transport. In order to validate the model, modeling results are compared with the experimentally measured data in various conditions.

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.

A Study on A Model Sample for Guidance System for Copyright of Domestic Journals and Open Access Policy (국내 학술지 저작권 및 오픈액세스 정책 안내시스템 모형 연구)

  • Kim, Gyuhwan
    • Journal of Korean Library and Information Science Society
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    • v.47 no.4
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    • pp.265-288
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    • 2016
  • The study aimed to suggest a model sample for guidance system for copyright of domestic journals and open access policy. Toward this end, analyses were conducted to examine copyright of domestic journals and open access environment. As a result of analyses, it turned out that 33.8% of domestic journals had 'regulations on ownership of rights to papers published in journals,' and that the subject to ownership of rights to papers published in domestic journals accounted for 28.8%, which was the highest rate. Of domestic journals, 34% charged a subscription fee, and they were toll access journals, and 56% were free access journals. As for system examples of guide system for copyright of foreign journals and open access policy, analyses were conducted to examine and investigate SHERPA/RoMEO in the U.K. and SCPJ in Japan and generate considerations at a time of domestic application. What needs to be taken into account is that overseas examples are focused on collecting and introducing self-archiving policy by authors for academic journals, so there are limitations in offering information including open access publication policy for domestic journals. Based on the analytical result, the study designated the purpose, direction and four steps that need to be considered at a time of development of guide system models for copyright and open access policy for domestic journals before suggestion of the basic direction and operational methods by stage.

In-situ TiO2 Formation and Performance on Ceramic Membranes in Photocatalytic Membrane Reactor (광촉매 반응기용 세라믹 막에의 TiO2 층 형성과 성능평가)

  • Ahmad, Rizwan;Kim, Jin Kyu;Kim, Jong Hak;Kim, Jeonghwan
    • Membrane Journal
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    • v.27 no.4
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    • pp.328-335
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    • 2017
  • Fabricating photocatalytic composite membrane with a mesoporous and tailored morphological structure would have significant implication for environmental remediation. In this study, we reported hybrid $TiO_2$ immobilized photocatalytic membrane and its application for the treatment of dye solution. Photocatalytic film with high porosity and homogeneity was fabricated by graft copolymer as polymer template. Hybridization of membrane filtration with photocatalysis was successfully achieved by photocatalytic membrane reactor developed. Result showed that membrane permeability was significantly reduced after immobilizing the $TiO_2$ film on bare $Al_2O_3$ support. The membrane characterization indicated that well organized $TiO_2$ film was successfully formed on $Al_2O_3$ support. Benefiting from the controlled morphology of $TiO_2$ film, the composite membrane exhibited almost complete degradation of organic dye within 5 h of filtration under UV illumination. Langmuir-Hinshelwood model explained degradation of organic dye. First-order rate constant was approximately six times with $TiO_2$ immobilized composite ceramic membrane, higher than the one with the bare $Al_2O_3$ support (0.0081 vs. $0.0013min^{-1}$).

Expression of the Floral Repressor miRNA156 is Positively Regulated by the AGAMOUS-like Proteins AGL15 and AGL18

  • Serivichyaswat, Phanu;Ryu, Hak-Seung;Kim, Wanhui;Kim, Soonkap;Chung, Kyung Sook;Kim, Jae Joon;Ahn, Ji Hoon
    • Molecules and Cells
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    • v.38 no.3
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    • pp.259-266
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    • 2015
  • The regulation of flowering time has crucial implications for plant fitness. MicroRNA156 (miR156) represses the floral transition in Arabidopsis thaliana, but the mechanisms regulating its transcription remain unclear. Here, we show that two AGAMOUS-like proteins, AGL15 and AGL18, act as positive regulators of the expression of MIR156. Small RNA northern blot analysis revealed a significant decrease in the levels of mature miR156 in agl15 agl18 double mutants, but not in the single mutants, suggesting that AGL15 and AGL18 co-regulate miR156 expression. Histochemical analysis further indicated that the double mutants showed a reduction in MIR156 promoter strength. The double mutants also showed reduced abundance of pri-miR156a and pri-miR156c, two of the primary transcripts from MIR156 genes. Electrophoretic mobility shift assays demonstrated that AGL15 directly associated with the CArG motifs in the MIR156a/c promoters. AGL18 did not show binding affinity to the CArG motifs, but pull-down and yeast two-hybrid assays showed that AGL18 forms a heterodimer with AGL15. GFP reporter assays and bimolecular fluorescence complementation (BiFC) showed that AGL15 and AGL18 co-localize in the nucleus and confirmed their in vivo interaction. Overexpression of miR156 did not affect the levels of AGL15 and AGL18 transcripts. Taking these data together, we present a model for the transcriptional regulation of MIR156. In this model, AGL15 and AGL18 may form a complex along with other proteins, and bind to the CArG motifs of the promoters of MIR156 to activate the MIR156 expression.

Application of An Ecological Engineering Approach in Evaluating Protected Area at Local Scales (생태계 보호지역 평가에서 생태공학 도입과 활용)

  • Koo, Kyung Ah
    • Journal of Environmental Impact Assessment
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    • v.29 no.2
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    • pp.144-155
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    • 2020
  • This research developed an approach to identify ecologically important areas at local scales and explained how the results of this approach could contribute to extend the protected areas in the Republic of Korea (ROK). While most developed countries have considered various biotic and abiotic factors, ecological processes, migration routes, habitat connectivity, ecosystem services, and etc. to determine the protected areas, ROK has considered a few factors focusing on biodiversity, landscape, and the habitats of endangered organisms. However, for sustainable management of our nature, we need comprehensive understanding of various ecosystem factors and interactions among them at local scales in designating protected areas. Forthis, we developed a conceptual model based on the ecological engineering approach and then explained how the results of this approach could contribute to extend the protected areas. In particular, we considered future land-use and climate change in determining the priority areas for novel protected areas. Our research suggested an effective methodology 1) to include various ecosystem factors and 2) to consider future environmental changes as well as current environmental conditions in finding the ecologically important areas and prioritizing these areas. However, our approach has limitations on the real-world applications due to the lack of fundamental information and data on our ecosystems. To improve the effectiveness of our approach in the real-world applications, we need various long-term ecological research results, environmental and ecological monitoring data, and both current and future spatial environmental data.

Supercomputing Performance Demand Forecasting Using Cross-sectional and Time Series Analysis (횡단면분석과 추세분석을 이용한 슈퍼컴퓨팅 성능수요 예측)

  • Park, Manhee
    • Journal of Technology Innovation
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    • v.23 no.2
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    • pp.33-54
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    • 2015
  • Supercomputing performance demand forecasting at the national level is an important information to the researchers in fields of the computational science field, the specialized agencies which establish and operate R&D infrastructure, and the government agencies which establish science and technology infrastructure. This study derived the factors affecting the scientific and technological capability through the analysis of supercomputing performance prediction research, and it proposed a hybrid forecasting model of applying the super-computer technology trends. In the cross-sectional analysis, multiple regression analysis was performed using factors with GDP, GERD, the number of researchers, and the number of SCI papers that could affect the supercomputing performance. In addition, the supercomputing performance was predicted by multiplying in the cross-section analysis with technical progress rate of time period which was calculated by time series analysis using performance(Rmax) of Top500 data. Korea's performance scale of supercomputing in 2016 was predicted using the proposed forecasting model based on data of the top500 supercomputer and supercomputing performance demand in Korea was predicted using a cross-sectional analysis and technical progress rate. The results of this study showed that the supercomputing performance is expected to require 15~30PF when it uses the current trend, and is expected to require 20~40PF when it uses the trend of the targeting national-level. These two results showed significant differences between the forecasting value(9.6PF) of regression analysis and the forecasting value(2.5PF) of cross-sectional analysis.

An Analysis on the Educational Needs for the Smart Farm: Focusing on SMEs in Jeon-nam Area (중소·중견기업의 스마트팜 교육 수요 분석: 전남지역을 중심으로)

  • Hwang, Doo-hee;Park, Geum-Ju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.649-655
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    • 2020
  • This study determined effective educational strategies by investigating and analyzing the related educational demands for SMEs (small and medium-sized enterprises) in the 4th Industrial Revolution based area of smart farms. In order to derive the approprate educational strategies, Importance-Performance Analysis (IPA) and Borich's Needs Assessment Model were conducted based on the smart farm technological field. As a result, the education demand survey showed high demand for production systems and intelligent farm machinery. In detail, Borich's analysis showed the need for pest prevention and diagnosis technology (8.03), network and analysis SW linkage technology (7.83), and intelligent farm worker-agricultural power system-electric energy hybrid technology (7.43). In contrast, smart plant factories (4.09), lighting technology for growth control (4.46) and structure construction technology (4.62) showed low demands. Based on this, the IPA portfolio shows that the network and analysis SW linkage technology and the CAN-based complex center are urgently needed. However, the technology that has already been developed, such as smart factory platform development, growth control lighting technology and structure construction technology, was oversized. Based on these results, it is possible to strategically suggest the customized training programs for industrial sectors of SMEs that reflect the needs for efficiently operating smart farms. This study also provides effective ways to operate the relevant training programs.

Environmental Impacts Assessment of Elementary School Buildings and Establishment of the Reference Target using Life Cycle Assessment Model (전과정평가 모델을 이용한 초등학교 건축물 환경영향 평가 및 비교기준 수립)

  • Ji, Changyoon;Hong, Taehoon;Jeong, Jaewook
    • Korean Journal of Construction Engineering and Management
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    • v.16 no.3
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    • pp.49-58
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    • 2015
  • In order to determine how much a new green building reduce the environmental impacts, it is necessary to establish the reference target for comparison. Therefore, this study aims to establish the reference target by evaluating the environmental impacts of existing buildings. To ensure this end, this study evaluated the environmental impacts(Global warming potential, ozone layer depletion potential, acidification potential, eutrophication potential, photochemical ozone creation potential, and abiotic depletion potential) of 17 existing elementary school buildings, which are located in Seoul, Busan, Daegu, and Gwangju, by using the hybrid LCA model. As a result, the environmental impacts of the case buildings were clearly distinguished in different regions. Therefore, this study presented the reference targets which are appropriate to each region. For example, the reference targets for global warming potential, which can be used in Seoul, Busan, Daegu, and Gwangju, are 3.76E+03, 1.90E+03, 2.63E+03, $2.81E+03kg-CO_2\;eq./m^2$, respectively. The presented reference targets are expected to be useful for understanding how much environmental impacts can be reduced when a new green school building is constructed.

Toxic Effects of Ethylene Glycol on Mammalian Embryo Survivability (Ethylene Glycol이 포유류 초기배자의 생존성에 미치는 독성 효과 분석)

  • Kim, Hyun;Yu, Dae Jung;Choe, Changyong;Seong, Hwan-Hoo
    • Reproductive and Developmental Biology
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    • v.39 no.3
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    • pp.77-81
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    • 2015
  • This study was carried out to evaluate the effects of embryonic stage and toxicities of cryoprotectant on the rates of survival and development of the cryopreserved mouse early embryo and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology. Toxicities of two cryoprotectants, dimethyl sulfoxide (DMSO) and ethylene glycol (EG) were investigated using a murine embryo model. Female F-1 mice were stimulated with gonadotropin, induced ovulation with hCG and mated. Two cell embryos were collected and cultured after exposure to either DMSO or EG. Embryo development was evaluated up to the blastocyst stage. The total cell count of blastocysts that were treated with DMSO ($68.1{\pm}24.1$) at the 2-cell stage was significantly lower than that were treated with EG ($81.2{\pm}27.0$) or the control ($99.0{\pm}18.3$) (p<0.001). On comparison of two cryoprotectant treated groups, the DMSO treated group showed a decreased cell count compared with the EG treated group (p<0.05). Both DMSO ($15.4{\pm}1.5$) and EG ($10.2{\pm}1.4$) treated groups showed higher apoptosis rates of cells in the blastocyst compared with the control ($6.1{\pm}0.9$, p<0.0001). In addition, the DMSO treated group showed more apoptotic cells than the EG treated group (p<0.001). The potential toxicity of cryoprotectants was uncovered by prolonged exposure of murine embryos to either DMSO or EG at room temperature. When comparing two cryoprotective agents, EG appeared to be less toxic than DMSO at least in a murine embryo model.