• Title/Summary/Keyword: 시뮬레이션 도구

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A Study on the Performance Evaluation of G2B Procurement Process Innovation by Using MAS: Korea G2B KONEPS Case (멀티에이전트시스템(MAS)을 이용한 G2B 조달 프로세스 혁신의 효과평가에 관한 연구 : 나라장터 G2B사례)

  • Seo, Won-Jun;Lee, Dae-Cheor;Lim, Gyoo-Gun
    • Journal of Intelligence and Information Systems
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    • v.18 no.2
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    • pp.157-175
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    • 2012
  • It is difficult to evaluate the performance of process innovation of e-procurement which has large scale and complex processes. The existing evaluation methods for measuring the effects of process innovation have been mainly done with statistically quantitative methods by analyzing operational data or with qualitative methods by conducting surveys and interviews. However, these methods have some limitations to evaluate the effects because the performance evaluation of e-procurement process innovation should consider the interactions among participants who are active either directly or indirectly through the processes. This study considers the e-procurement process as a complex system and develops a simulation model based on MAS(Multi-Agent System) to evaluate the effects of e-procurement process innovation. Multi-agent based simulation allows observing interaction patterns of objects in virtual world through relationship among objects and their behavioral mechanism. Agent-based simulation is suitable especially for complex business problems. In this study, we used Netlogo Version 4.1.3 as a MAS simulation tool which was developed in Northwestern University. To do this, we developed a interaction model of agents in MAS environment. We defined process agents and task agents, and assigned their behavioral characteristics. The developed simulation model was applied to G2B system (KONEPS: Korea ON-line E-Procurement System) of Public Procurement Service (PPS) in Korea and used to evaluate the innovation effects of the G2B system. KONEPS is a successfully established e-procurement system started in the year 2002. KONEPS is a representative e-Procurement system which integrates characteristics of e-commerce into government for business procurement activities. KONEPS deserves the international recognition considering the annual transaction volume of 56 billion dollars, daily exchanges of electronic documents, users consisted of 121,000 suppliers and 37,000 public organizations, and the 4.5 billion dollars of cost saving. For the simulation, we analyzed the e-procurement of process of KONEPS into eight sub processes such as 'process 1: search products and acquisition of proposal', 'process 2 : review the methods of contracts and item features', 'process 3 : a notice of bid', 'process 4 : registration and confirmation of qualification', 'process 5 : bidding', 'process 6 : a screening test', 'process 7 : contracts', and 'process 8 : invoice and payment'. For the parameter settings of the agents behavior, we collected some data from the transactional database of PPS and some information by conducting a survey. The used data for the simulation are 'participants (government organizations, local government organizations and public institutions)', 'the number of bidding per year', 'the number of total contracts', 'the number of shopping mall transactions', 'the rate of contracts between bidding and shopping mall', 'the successful bidding ratio', and the estimated time for each process. The comparison was done for the difference of time consumption between 'before the innovation (As-was)' and 'after the innovation (As-is).' The results showed that there were productivity improvements in every eight sub processes. The decrease ratio of 'average number of task processing' was 92.7% and the decrease ratio of 'average time of task processing' was 95.4% in entire processes when we use G2B system comparing to the conventional method. Also, this study found that the process innovation effect will be enhanced if the task process related to the 'contract' can be improved. This study shows the usability and possibility of using MAS in process innovation evaluation and its modeling.

The Effects of RSM-Based Astronomical Observation Program on Astronomical Spatial Concept and Self-Directed Learning for the Scientific Gifted Students (과학영재 학생을 위한 RSM 기반 천체관측 프로그램이 천문학적 공간개념과 자기주도적 학습능력에 미치는 효과)

  • Shin, Myeung-Ryeul;Lee, Yong-Seob
    • Journal of Gifted/Talented Education
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    • v.21 no.4
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    • pp.993-1009
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    • 2011
  • The purpose of this study was to find the effects of RSM-based astronomical observation program about Astronomical Spatial Concept and Self-Directed Learning for the Scientific Gifted Students. For this purpose, this research developed RSM-based astronomical observation program. This program was totally consisted 10 lessen. there was 3 part in this program. It contained Preparation Stage (step 1-2), Observation Stage (step 3-8), Clean up Stage (step 9-10). To find the effects of RSM-based astronomical observation program on Astronomical Spatial Concept and Self-Directed Learning for Scientific Gifted Students. 20 participants was selected. these students were attended at a scientific gifted class(5th grade) of an elementary school located in Ulsan. First, Astronomical Spatial Concept was used to find the effect of the Astronomical Observation program based RSM. And the results were analyzed by SPSSWIN 18.0. The results of this study were as follows. First, RSM-based astronomical observation program was a positive effects on Astronomical Spatial Concept of the Scientific Gifted Students (t=3,875, p=.001). Second, RSM-based astronomical observation program was a positive effects on Self-Directed Learning of the Scientific Gifted Students (t=5.783, p=.000). According to this research, RSM-based astronomical observation program was verified to improve Astronomical Spatial Concept and Self-Directed Learning on the Scientific Gifted Students. It will be contribute on the curriculum construction of the gifted school or gifted class.

A Study on the Application Direction of Finite Element Analysis in the Field of Packaging through Research Trend Analysis in Korea (국내 연구 동향 분석을 통한 포장분야에서 유한요소해석의 적용 방향에 관한 고찰)

  • Lee, Hakrae;Jeon, Kyubae;Ko, Euisuk;Shim, Woncheol;Kang, Wookgun;Kim, Jaineung
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.23 no.3
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    • pp.191-200
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    • 2017
  • Proper packaging design can meet both the environmental and economic aspects of packaging materials by reducing the use of packaging materials, waste generation, material costs, and logistics costs. Finite element analysis(FEM) is used as a useful tool in various fields such as structural analysis, heat transfer, fluid motion, and electromagnetic field, but its application in the field of packaging is still insufficient. Therefore, the application of FEM to the field of packaging can save the cost and time in the future research because it is possible to design the package by computer simulation, and it is possible to reduce the packaging waste and logistics cost through proper packaging design. Therefore, this study investigated the FEM papers published in Korea for the purpose of helping research design using FEM program in the field of packaging in the future. In this paper, we analyzed the 29 papers that were directly related to the analysis of FEM papers published in domestic journals from 1991 to 2017. As a result, we analyzed the research topic, FEM program, and analysis method using each paper, and presented the direction that can be applied in future packaging field. When the FEM is applied to the packaging field, it is possible to change the structure and reduce the thickness through the stress and vibration analysis applied to the packaging material, thereby reducing the cost by improving the mechanical strength and reducing the amount of the packaging material. Therefore, in the field of packaging research in the future, if the FEM is performed together, economical and reasonable packaging design will be possible.

Measurement and Monte Carlo Simulation of 6 MV X-rays for Small Radiation Fields (선형가속기의 6 MV X-선에 대한 소형 조사면 측정과 몬테 카를로 시뮬레이션)

  • Jeong Dong Hyeok;Lee Jeong Ok;Kang Jeong Ku;Kim Soo Kon;Kim Seung Kon;Moon Sun Rock
    • Radiation Oncology Journal
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    • v.16 no.2
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    • pp.195-202
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    • 1998
  • Purpose : In order to obtain basic data for treatment plan in radiosurgery, we measured small fields of 6 MV X-rays and compared the measured data with our Monte Carlo simulations for the small fields. Materials and Methods : The small fields of 1.0, 2.0 and 3.0 cm in diameter were used in this study. Percentage depth dose (PDD) and beam Profiles of those fields were measured and calculated. A small semiconductor detector, water phantoms, and a remote control system were used for the measurement Monte Carlo simulations were Performed using the EGS4 code with the input data prepared for the energy distribution of 6 MV X-rays, beam divergence, circular fields and the geometry of the water phantoms. Results : In the case of PDD values, the calculated values were lower than the measured values for all fields and depths, with the differences being 0.3 to 5.7% at the depths of 20 to 20.0 cm and 0.0 to 8.9% at the surface regions. As a result of the analysis of beam profiles for all field sizes at a depth of loom in water phantom, the measured 90% dose widths were in good agreement with the calculated values, however, the calculated Penumbra radii were 0.1 cm shorter than measured values. Conclusion : The measured PDDs and beam profiles agreement with the Monte Carlo calculations approximately. However, it is different when it comes to calculations in the area of phantom surface and penumbra because the Monte Carlo calculations were performed under the simplified geometries. Therefore, we have to study how to include the actual geometries and more precise data for the field area in Monte Carlo calculations. The Monte Carlo calculations will be used as a useful tool for the very complicated conditions in measurement and verification.

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Thought Experiments: on the Working Imagination and its Limitation (사고실험 - 상상의 작용과 한도에 대해)

  • Hwang, Hee-sook
    • Journal of Korean Philosophical Society
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    • v.146
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    • pp.307-328
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    • 2018
  • The use of thought experiments has a long history in many disciplines including science. In the field of philosophy, thought experiments have frequently appeared in the pre-existing literature on the contemporary Analytic Philosophy. A thought experiment refers to a synthetic environment where the designer of the experiment-with his or her intuition and imagination-tests common-sense knowledge. It can be understood as a conceptual tool for testing the validity of the common understanding of an issue or a phenomenon. However, we are not certain about the usefulness or efficacy of a thought experiment in knowledge production. The design of a thought experiment is meant to lure readers into believing as intended by the experiment itself. Thus, regardless of the purpose of a thought experiment, many readers who encounter the experiment could feel deceived. In this paper, to analyze the logic of thought experiments and to seek the source of uneasiness the readers and critics may feel about thought experiments, I draw lessons from three renowned thought-experiments: Thomson's 'ailing violinist', Putnam's 'brain in a vat', and Searle's 'Chinese room'. Imaginative thought experiments are usually constructed around a gap between the reality and the knowledge/information at hand. From the three experiments, several lessons can be learned. First, the evidence of the existence of a gap provided via thought experiments can serve as arguments for counterfactual situations. At the same time, the credibility and efficacy of the thought experiments can be damaged as soon as the thought-experiments are carried out with inappropriate and/or murky directions regarding the procedures of the experiment or the background of the study. According to D. R. Hofstadter and D. C. Dennett(1981), the 'knob setting' in a thought experiment can be altered in the middle of a simulation of the experimental condition, and then the implications of the thought experiment change altogether, indicating that an entirely different conclusion can be deduced from thought experiment. Lastly, some pre-suppositions and bias of the experiment designers play a considerable role in the validity and the chances of success of a thought experiment; thus, it is recommended that the experiment-designers refrain from exercising too much of their imagination in order to avoid contaminating the design of the experiment and/or wrongly accepting preconceived/misguided conclusions.

The Photography as Technological Aesthetics (데크놀로지 미학으로서의 사진)

  • Jin, Dong-Sun
    • Journal of Science of Art and Design
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    • v.11
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    • pp.221-249
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    • 2007
  • Today, photography is facing to the crisis of identity and dilemma of ontology from the digital imaging process in the new technology form. It is very important points to say rethinking of the traditional photographic medium, that has changed the way we view the world and ourselves is perhaps an understatement and that photography has transformed our essential understanding of reality. Now, no longer are photographic images regarded as the true automatic recording, innocent evidence and the mirror to the reality. Rather, photography constructs the world for our entertainment, helping to create the comforting illusions by which we live. The recognition that photographs are not constructions and reflections of reality, is the basis for the actual presence within the contemporary photographic world. It is shock. This thesis's aim is to look for the problems of photographic identity and ontological crisis that is controlling and regulating digital photographic imagery, allowing the reproduction of the electronic simulations era. Photography loses its special aesthetic status and becomes no more true information and, exclusively evidence by traditional film and paper that appeared both as a technological accuracy and as a medium-specific aesthetic. The result, photography is facing two crises, one is the photographic ontology(the introduction of computerized digital images) and the other is photographic epistemology(having to do broader changes in ethics, knowledge and culture). Taken together, these crises apparently threaten us with the death of photography, with the 'end' of photography and the culture it sustains. The thesis's meaning is to look into the dilemma of photography's ontology and epistemology, especially, automatical index and digital codes from its origin, meaning, and identity as the technological medium. Thus, in particular, thesis focuses on the analog imagery presence, from the nature in the material world, and the digital imagery presence from the cultural situations in our society. And also thesis's aim is to examine the main issues of the history of photography has been concentrated on the ontological arguments since the discovery of photography in 1839. Photography has never been only one static technology form. Rather, its nearly two centuries of technological development have been marked by numerous, competing of technological innovation and self revolution from the dual aspects. This thesis examines recent account of photography by the analysis of the medium's concept, meaning, identity between film base image and digital base image from the aspects of photographic ontology and epistemology. Thus, the structure of thesis is fairy straightforward to examine what appear to be two opposing view of photographic conditions and ontological situations. Thesis' view contrasts that figure out the value of photography according to its fundamental characteristic as a medium. Also, it seeks a possible solution to the dilemma of photographic ontology through the medium's origin from the early years of the nineteenth century to the raising questions about the different meaning(analog/digital) of photography, now. Finally, this thesis emphasizes and concludes that the photographic ontological crisis reflects to the paradoxical dynamic structure, that unsolved the origins of the medium, itself. Moreover, even photography is not single identity of the photographic ontology, and also can not be understood as having a static identity or singular status from the dynamic field of technologies, practices, and images.

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