• Title/Summary/Keyword: abstraction

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Combined Effects of Groundwater Abstraction and Irrigation Reservoir on Streamflow (지하수 이용과 농업용 저수지가 하천유량에 미치는 복합 영향)

  • Kim, Nam Won;Lee, Jeongwoo;Chung, Il Moon;Lee, Min Ho
    • Journal of Korea Water Resources Association
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    • v.46 no.7
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    • pp.719-733
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    • 2013
  • In this study, a watershed-based surface-water and groundwater integrated model, SWAT-MODFLOW was used to evaluate streamflow depletion induced by groundwater withdrawals and irrigation reservoirs for the Juksan-cheon watershed in South Korea. The streamflow responses to groundwater pumping and irrigation reservoirs were simulated under several different scenarios. The scenarios were (1) current pumping well withdrawals with reservoirs; (2) current pumping well withdrawals without reservoirs; (3) no pumping well withdrawals with reservoirs; (4) no pumping well withdrawals without reservoirs (natural condition). The simulated results indicated that the effects of groundwater pumping on streamflow depletion are a little more significant than those of irrigation reservoirs. Particularly, the groundwater withdrawals with irrigation reservoirs at current status (scenario 1) has induced the decrease of more than 20% in drought flow against the natural condition (scenario 4) at the outlet of the watershed. The specific drought flows through the main stream of Juksan-cheon watershed were simulated in order to assess the irrigation effects on downstream flows. It was found out that the specific drought flows are increasing as the distance from the reservoir increases due to the accumulation of the return flows to stream.

Expression Techniques and Aesthetic Values of Head Dress Reflected on Natural Motif (자연적 모티프가 반영된 헤드 드레스의 표현 기법과 미적 가치)

  • Kim, Young-Sam;Kim, Young-Min;Kim, Jang-Hyeon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.40 no.4
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    • pp.746-762
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    • 2016
  • This study considers expression techniques and aesthetic values in the images of head dress reflected in a natural motif. The conclusions of the study are as follows. The first type is the realistic expression (52.4%) such as the reproduction of a natural object's essential form (27.0%), the partial derivation of the natural object (19.3%), and the planarization for the actual image of the natural object (6.1%). The second type is a metaphorical expression (39.0%) which emphasizes the morphological characteristics of nature (18.2%), the structuration of the natural object's silhouette into a three-dimensional or two-dimensional form (11.5%), and the abstract expression of the form in the natural object (9.3%). The third type is a hybrid expression (8.6%) that is a compromise between practical (or metaphorical expressions) so that expression techniques represent a compromise between the natural object's essential form and abstract expression (4.6%) or the combination of the natural object's silhouette into a three-dimensional or a two-dimensional visualization (4.0%). Aesthetic head dress values reflected in the natural motif first indicate a primitive value. This state of natural instinct recreates the natural object or combines part of the biological elements of the natural object to create an inducement to escape from the practical world. The second is amusement in the expression of animals in dynamic and humorous forms creates an illusion of animals being alive with a representative playful enjoyment. The third is abstraction that grant freedom in the observer's aesthetic rational through a reinterpretation of the fashion designer. The fourth is eclecticism where a compromise represents an act of mixing a variety of independent factors to create harmony with the imagery of nature created through the grafting of diverse expression techniques that break away from stereotypes of existing natural objects to create a type of nature that cultivates new values.

Requirement Analysis of a System to Predict Crop Yield under Climate Change (기후변화에 따른 작물의 수량 예측을 위한 시스템 요구도 분석)

  • Kim, Junhwan;Lee, Chung Kuen;Kim, Hyunae;Lee, Byun Woo;Kim, Kwang Soo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.1
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    • pp.1-14
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    • 2015
  • Climate change caused by elevated greenhouse gases would affect crop production through different pathways in agricultural ecosystems. Because an agricultural ecosystem has complex interactions between societal and economical environment as well as organisms, climate, and soil, adaptation measures in response to climate change on a specific sector could cause undesirable impacts on other sectors inadvertently. An integrated system, which links individual models for components of agricultural ecosystems, would allow to take into account complex interactions existing in a given agricultural ecosystem under climate change and to derive proper adaptation measures in order to improve crop productivity. Most of models for agricultural ecosystems have been used in a separate sector, e.g., prediction of water resources or crop growth. Few of those models have been desiged to be connected to other models as a module of an integrated system. Threfore, it would be crucial to redesign and to refine individual models that have been used for simulation of individual sectors. To improve models for each sector in terms of accuracy and algorithm, it would also be needed to obtain crop growth data through construction of super-sites and satellite sites for long-term monitoring of agricultural ecosystems. It would be advantageous to design a model in a sector from abstraction and inheritance of a simple model, which would facilitate development of modules compatible to the integrated prediction system. Because agricultural production is influenced by social and economical sectors considerably, construction of an integreated system that simulates agricultural production as well as economical activities including trade and demand is merited for prediction of crop production under climate change.

Homolytic Reactions of Isonitriles (이소니트릴의 자유라디칼반응)

  • Sung Soo Kim
    • Journal of the Korean Chemical Society
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    • v.24 no.3
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    • pp.250-258
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    • 1980
  • Various radicals may add to isonitriles to give imidoyl radcals RN=CR'. This may be also generated via abstraction of imidoyl hydrogen from imine in the following manner: RN=CR' + R"${\cdot}{\rightarrow}$ RN=CR' + R"-H Imidoyl radicals would be stabilized via two pathways, ${\beta}$-cleavage and atom transfer reactions. ${\beta}$-Cleavage may occur in two directions depending upon structure of the radicals. Cyanide transfer and the "so-called" normal ${\beta}$-cleavage are the two modes of ${\beta}$-cleavage. Addition of t-butoxy radical to t-butyl isocyanide 7 generates an imidoyl radical t-Bu-N=C-O-Bu-t, which undergoes ${\beta}$-cleavage to give t-butyl isocyanate and t-butyl radical. Addition of phenyl radical to 7 forms the intermediate radical t-Bu-N=$C-C_6H_5$, which decomposes to give benzonitrile and t-butyl radical. The t-butyl radical generated from the ${\beta}$-cleavage adds to 7 giving the radical t-Bu-N=C-Bu-t, which cleaves only to pivalonitrile and t-butyl radical, inducing radical chain isomerization. Trimethylsilyl radical adds to 7 to give the intermediate t-Bu-N=$C-Si(CH_3)_3$, which collapses to $(CH_3)_3$SiCN and a t-butyl radical.

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Effects of Representation Forms on Analysts' Identification of Systems Development Problems - An Empirical Study -

  • Kim, Jong-Uk
    • Asia pacific journal of information systems
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    • v.10 no.2
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    • pp.71-95
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    • 2000
  • Despite repeated exhortation about the importance of social and human dimensions of systems development, socio-organizational issues continue to be neglected and ignored in the current information systems practice. A review of the human information processing literature suggests that the reasons for this continuing lack of attention to social issues may be found in the limitations of human cognition and information processing capacities. Bostrom and Heinen(1978) and Kumar and Bjorn-Anderson(1990) also suggest that the inadequate attention to social problems and issues by the analyst could originate from the analysts limited problem perception. This research explores how the representation forms of information systems(IS) methodology used in understanding and modeling the problem situation affect such systems development problem perception. Typically, a system development methodology prescribes the use of system models(i.e., system representations) to understand, analyze, evaluate, and design the information system. Given the size and complexity of information systems, and the abstraction and simplification underlying the modeling process, system representations usually depict only a limited set of aspects of the system. Thus, a methodology whose representations are limited to technical aspects will tend to limit the analyst's perspective to a technical one only(Kumar & Welke, 1990). Following the same line of argument, in contrast, it is the conjecture of this study that a methodology which specifies both social and technical aspects of IS development will help the analyst develop a more comprehensive view of the IS problem domain. Based on the above concept, a theoretical model was first developed which explained the systems analysts cognitive process. Drawing on this model, a research model was developed hypothesizing the impacts of representation forms on problem identification. The model was tested using a laboratory experiment with 70 individual subjects. A special computer software was developed with a hypermedia authoring tool to conduct the experiments in order to avoid experimenter biases and to maintain consistency in administrating repeated experiments. The program, designed to replace the experimenter, consisted of functions such as presenting the subjects with problem material, asking the subjects questions, and saving the typed answers of the subjects. The results indicate that representation forms strongly influence problem identification. It was found that the use of the socio-technical representation form led to the findings of more social problems than the use of technical representation form. The results imply significant effects of representation forms on problem findings and also suggest that the use of adequate representation forms may help overcome dysfunctional effects of our limited information processing capacity.

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Gender and Abstract Thinking Disposition Difference Analyses of Visual Diagram Structuring for Computational Thinking Ability (컴퓨팅 사고력을 위한 시각적 다이어그램 구조화의 성별 및 추상적 사고 성향 차이 분석)

  • Park, Chan Jung;Hyun, Jung Suk
    • The Journal of Korean Association of Computer Education
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    • v.21 no.3
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    • pp.11-20
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    • 2018
  • One major change in the 2015 revised national curriculum is that computational thinking ability is becoming an essential competency for students. Computational thinking is divided into abstraction, automation, and creative convergence in the curriculum for secondary schools' Information subject. And, the curriculum contains problem solving and programming area. Among the components of computational thinking, data representation emphasizes the ability to structure data and information for problem solving of learners. Pre-service teachers of Information subject at secondary schools also learn how to structure information through diagramming. There are differences in the ability to structure diagrams among students, but the studies on learning methods that help students develop their structuring abilities have rarely been performed. The purpose of this paper is to analyze the differences of abstract thinking disposition and gender perspective among college students. As a result, female students had more concrete thinking disposition than male students. Also, there were gender differences according to the characteristics of diagrams. Differences in abstract thinking disposition also made a difference in structuring diagrams. It is useful for achieving the education purpose of improving computational thinking ability by finding out the differences in thinking tendency between males and females and finding the education method that can complement them.

Development of a GIS-Based Basin Water Balance Analysis Model (GIS 기반의 유역물수지 분석모형 개발)

  • Hwang, Eui-Ho;Kim, Kye-Hyun;Park, Jin-Hyeog;Lee, Geun-Sang
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.4
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    • pp.34-45
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    • 2004
  • Existing Semangeum's water balance analysis simplifies whole basin to single basin and achieved volume of effluence that produce by Kajiyama way to foundation. But Semangeum is complicated and various rice-wine strainer supply system. And there is difficulty to apply as elastic when water balance element is changed at free point. Divided to unit possession station for suitable water balance analysis model application to Semangeum in this study. And developed basin water balance model of GIS base that can do details analysis is bite about development and transfer of an appropriation in the budget of basin water resources. Achieved study including abstraction and concept design that use UML (unified modeling language) diagram for details analysis, stream network composition for rice-wine strainer supply system application, preprocessing of GIS base and postprocessing module development, model revision and verification etc. Support of this water balance analysis model is available to establish efficient water resources administration plan through outward flow process analysis of water resources. And support is considered to be possible in more convenient and, reasonable water resources administration way establishment by minimizing manual processing in systematic water resources government official to user and support diversified analysis system.

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Design and Implementation of HPC Job Management Framework for Computational Scientific Simulation (계산과학 시뮬레이션을 위한 HPC 작업 관리 프레임워크의 설계 및 구현)

  • Yu, Jung-Lok;Kim, Han-Gi;Byun, Hee-Jung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.554-557
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    • 2016
  • Recently, supercomputer has been increasingly adopted as a computing environment for scientific simulation as well as education, healthcare and national defence. Especially, supercomputing system with heterogeneous computing resources is gaining resurgence of interest as a next-generation problem solving environment, allowing theoretical and/or experimental research in various fields to be free of time and spatial limits. However, traditional supercomputing services have only been handled through a simple form of command-line based console, which leads to the critical limit of accessibility and usability of heterogeneous computing resources. To address this problem, in this paper, we provide the design and implementation of web-based HPC (High Performance Computing) job management framework for computational scientific simulation. The proposed framework has highly extensible design principles, providing the abstraction interfaces of job scheduler (as well as bundle scheduler plug-ins for LoadLeveler, Sun Grid Engine, OpenPBS scheduler) in order to easily incorporate the broad spectrum of heterogeneous computing resources such as cluster, computing cloud and grid. We also present the detailed specification of HTTP standard based RESTful endpoints, which manage simulation job's life-cycles such as job creation, submission, control and status monitoring, etc., enabling various 3rd-party applications to be newly created on top of the proposed framework.

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A Formal Modeling of Managed Object Behaviour with Dynamic Temporal Properties (동적 시간지원 특성을 지원하는 망관리 객체의 정형적 모델링)

  • Choi, Eun-Bok;Lee, Hyung-Hyo;Noh, Bong-Nam
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.1
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    • pp.166-180
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    • 2000
  • Recommendations of ITU-T and ISO stipulate the managerial abstraction of static and dynamic characteristics of network elements, management functions as well as management communication protocol. The current recommendations provide the formal mechanism for the structural parts of managed objects such as managed object class and attributes. But the current description method does not provide the formal mechanism for the behavioral characteristics of managed objects in clear manner but in natural language form, the complete specification of managed objects is not fully described. Also, the behaviour of managed objects is affected by their temporal and active properties. While the temporal properties representing periodic or repetitive internals are to describe managed objects behaviour in rather strict way, it will be more powerful if more dynamic temporal properties determined by external conditions are added to managed objects. In this paper, we added dynamic features to scheduling managed objects, and described, in GDMO, scheduling managed objects that support dynamic features. We also described behaviour of managed objects in newly defined BDL that has dynamic temporal properties. This paper showed that dynamic temporal managed objects provide a systematic and formal method in agent management function model.

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Relationship between Percutaneous Transluminal Coronary Anigioplasty Volume and Associated Immediate Outcome (경피적 관동맥 확장술의 시술량과 조기 시술결과의 관련성)

  • Kim, Yong-Ik;Kim, Chang-Yup;Lee, Young-Sung;Kim, Sun-Mean;Lee, Jin-Seok;Oh, Byung-Hee;Khang, Young-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.34 no.1
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    • pp.9-20
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    • 2001
  • Objectives : To explore the relationship between Percutaneous Transluminal Coronary Angioplasty(PTCA) volume and the associated immediate outcome. Methods : A total of 1,379 PTCAs were peformed in 25 hospitals in Korea between October 8 and December 31 in 1997. Data from 1,317 PTCAs (95.5%) were collected through medical record abstraction. Inter-observer reliability of the data was examined using the Kappa statistic on a subsample of 110 PTCA procedures from five hospitals. Intra-observer reliability of the data was also examined. PTCA success and immediate adverse outcomes were selected as the outcome variables. A successful PTCA was defined as a case that shows less than 50% diameter stenosis and more than 20% reduction of diameter stenosis. Immediate adverse outcomes included deaths during the same hospitalization, emergency coronary artery bypass graft (CABG) within 24 hours after PTCA, and acute myocardial infarction within 24 hours after PTCA. The numbers of PTCAs performed in 1997 per hospital were used as the volume variables. Results : Without adjusting for patient risk factors that may affect outcomes, procedures at high volume hospitals ($\geq200$ cases per year) had a greater success rate (P=0.001) than low volume hospitals. There was a marginally significant difference (P=0.070) in major adverse outcome rates between high and low volume hospitals. After adjusting for risk factors, there were significant differences in procedural failure and major adverse outcome rates between high and low volume hospitals. Conclusions : After adjusting for patient clinical risk factors, the hospital volume of PTCA was associated with immediate outcomes. It is recommended that a PTCA volume per year be established in order to improve the immediate outcome of this procedure in Korea.

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