• 제목/요약/키워드: Realistic Problem

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자동차 패널 자동창고 시스템의 PLC 시뮬레이션 적용 연구 (A Study of PLC Simulation for Automobile Panel AS/RS)

  • 고민석;구락조;곽종근;홍상현;왕지남;박상철
    • 한국시뮬레이션학회논문지
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    • 제18권3호
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    • pp.1-11
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    • 2009
  • 본 논문에서는 자동차 패널 자동창고 시스템의 PLC 시뮬레이션 적용 연구 사항에 관해 소개한다. 자동차 차종의 증가에 따라 차종 별 패널 공급의 복잡도가 향상되었다. 이를 해결하기 위해 AS/RS 시스템을 사용하지만, 내부 시스템 로직의 복잡성으로 인해 사전에 검증하는 것이 매우 어렵다. 특히 AS/RS시스템 제어의 중추적 역할을 하는 PLC는 하위 레벨의 언어로 기술되기 때문에, 사용자가 정확히 이해하고 검증을 수행하기 힘든 것이 현실이다. 본 논문에서는 이 같은 논리적 복잡성과 언어적 한계를 극복하고자 PLC 와 3D 모델을 연동하는 시뮬레이션 환경을 제안하였다. 특히 차체 조립라인의 설비 및 패널 데이터를 실측치를 기반으로 하였고, 실제 PLC 신호를 이용하여 환경을 구축함으로써 시스템 구축 이전에 시운전 환경을 완벽히 구현하였다. 사용자는 제안된 시뮬레이션 환경에서 AS/RS 로직을 시운전 할 수 있게 되었고, 이를 통해 경제적, 시간적 이득을 얻게 되는 장점을 갖는다.

Numerical Method for Exposure Assessment of Wireless Power Transmission under Low-Frequency Band

  • Kim, Minhyuk;Park, SangWook;Jung, Hyun-Kyo
    • Journal of Magnetics
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    • 제21권3호
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    • pp.442-449
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    • 2016
  • In this paper, an effective numerical analysis method is proposed for calculating dosimetry of the wireless power transfer system operating low-frequency ranges. The finite-difference time-domain (FDTD) method is widely used to analyze bio-electromagnetic field problems, which require high resolution, such as a heterogeneous whole-body voxel human model. However, applying the standard method in the low-frequency band incurs an inordinate number of time steps. We overcome this problem by proposing a modified finite-difference time-domain method which utilizes a quasi-static approximation with the surface equivalence theorem. The analysis results of the simple model by using proposed method are in good agreement with those from a commercial electromagnetic simulator. A simulation of the induced electric fields in a human head voxel model exposed to a wireless power transmission system provides a realistic example of an application of the proposed method. The simulation results of the realistic human model with the proposed method are verified by comparing it with the conventional FDTD method.

우리나라 의료판례 변화에 대한 비판적 고찰 - 판결양식과 손해배상액을 중심으로 - (Critical Overview on Changes of Judicial Precedents in the Medical Cases of Korea - In Relation with Forms of Judgments and Damages -)

  • 신현호
    • 의료법학
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    • 제15권1호
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    • pp.83-122
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    • 2014
  • Compared with medical cases and health care law from other countries there has been a lot of progress on medical law, especially on medical precedents in Korea. However, in recent years, medical precedents tend to reflect a realistic position of health care providers, rather than normative position of the victim. The burden of proof to prove strict liability is given to patients in civil law suits by courts, patients generally has the burden of proof. The rate of claims to prove the negligence of medical malpractice is falling significantly. Even if the error is acknowledged, it is not enough to get right to be relief for patients by increasing limitations of liability or ratio of patient's own negligence. Compensation fee is included in medical fees and risk of medical malpractice actions contributes ultimately to a health care consumer. In conclusion, author represents a major the new upgrade of above mentioned problem. By advising that court should assess actively for the perspective of victim for medical negligence we will be able to exercise remedies of patients' rights and to prevent recurring medical accidents and also contribute to medical advances.

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무인지상차량의 안전주행을 고려한 최적경로 생성 방법 (An Optimal Path Generation Method considering the Safe Maneuvering of UGV)

  • 곽경운;정해관;최덕선;박용운;곽윤근;김수현
    • 한국군사과학기술학회지
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    • 제13권6호
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    • pp.951-957
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    • 2010
  • An optimal path generation method considering the safety of UGV(Unmanned Ground Vehicle) is proposed and demonstrated through examples. Among various functions of UGV, real-time obstacle avoidance is a key issue to realize realistic scenario in FCS(Future Combat Systems). A two-dimensional narrow corridor environment is considered as a test field. For each step of UGV movement, two objectives are considered: One is to minimize the distance to the target and the other to maximize the distance to the nearest point of an obstacle. A weighted objective function is used in the optimization problem. Equality and inequality constraints are taken to secure the UGV's dynamics and safety. The weighting factors are controlled by a fuzzy controller which is constructed by a fuzzy rule set and membership functions. Simulations are performed for two cases. First the weighting factors are considered as constant values to understand the characteristics of the corresponding solutions and then as variables that are adjusted by the fuzzy controller. The results are satisfactory for realistic situations considered. The proposed optimal path generation with the fuzzy control is expected to be well applicable to real environment.

오일러 알고리즘의 안내된 재 발명 -RME 기반 미분 방정식 수업에서 점진적 수학화 과정 분석- (Guided Reinvention of Euler Algorithm: -An Analysis of Progressive Mathematization in RME-Based Differential Equations Course-)

  • 권오남;주미경;김영신
    • 한국수학교육학회지시리즈A:수학교육
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    • 제42권3호
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    • pp.387-402
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    • 2003
  • Realistic Mathematics Education (RME) focuses on guided reinvention through which students explore experientially realistic context problems to develop informal problem solving strategies and solutions. This research applied this philosophy of RME to design a differential equation course at a university level. In particular, the course encouraged the students of the course to use numerical methods to solve differential equations. In this context, the purpose of this research was to describe the developmental process in which the students constructed and reinvented Euler algorithm in the class. For the purpose, this paper will present the didactical principle of RME and describe the process of developmental research to investigate the inferential process of students in solving the first order differential equation numerically. Finally, the qualitative analysis of the students' reasoning and use of symbols reveals how the students reinvent Euler algorithm under the didactical principle of guided reinvention. In this research, it has been found that the students developed deep understanding of Euler algorithm in the class. Moreover, it has been shown that the experience of doing mathematics in the course had a positive impact on students' mathematical belief and attitude. These findings imply that the didactical principle of RME can be applied to design university mathematical courses and in general, provide a perspective on how to reform mathematics curriculum at a university level.

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에너지 플럭스 모델을 활용한 해저 잔향음 신호 모의 (Simulation of time-domain bottom reverberation signal using energy-flux model)

  • 정영철;이근화;성우제;김성일
    • 한국음향학회지
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    • 제38권1호
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    • pp.96-105
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    • 2019
  • 능동소나 시뮬레이터에서 실제와 유사하고 실시간 운용 가능토록 설계하는데 가장 제한적인 요소는 잔향음이다. 잔향음 모의는 계산시간이 많이 소요되어 시뮬레이터에 반영하고 실시간으로 신호를 생성하는데 한계가 있었다. 본 연구에서는 Harrison의 에너지 플럭스 해저 잔향음 모델을 기반으로 함정 기동에 따른 도플러 효과와 자기회귀 모델을 적용하여 해저 잔향음 시계열 신호를 모의하였다. 최종적으로 해군연구국 잔향음 워크숍-I 11번 문제와 동해 해양환경을 토대로 모의 한 결과, 실제와 유사한 특징의 해저 잔향음 신호를 생성할 수 있었다.

공급사슬네트워크에서 시뮬레이션과 유전알고리즘을 이용한 통합생산분배계획에 대한 연구 (Study of Integrated Production-Distribution Planning Using Simulation and Genetic Algorithm in Supply Chain Network)

  • 임석진
    • 대한안전경영과학회지
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    • 제22권4호
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    • pp.65-74
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    • 2020
  • Many of companies have made significant improvements for globalization and competitive business environment The supply chain management has received many attentions in the area of that business environment. The purpose of this study is to generate realistic production and distribution planning in the supply chain network. The planning model determines the best schedule using operation sequences and routing to deliver. To solve the problem a hybrid approach involving a genetic algorithm (GA) and computer simulation is proposed. This proposed approach is for: (1) selecting the best machine for each operation, (2) deciding the sequence of operation to product and route to deliver, and (3) minimizing the completion time for each order. This study developed mathematical model for production, distribution, production-distribution and proposed GA-Simulation solution procedure. The results of computational experiments for a simple example of the supply chain network are given and discussed to validate the proposed approach. It has been shown that the hybrid approach is powerful for complex production and distribution planning in the manufacturing supply chain network. The proposed approach can be used to generate realistic production and distribution planning considering stochastic natures in the actual supply chain and support decision making for companies.

Realistic Visualization of Car Configurator Based On Unreal Engine 4(UE4)

  • Zhong, Yiming;Yun, Tae Soo;Lee, Byung Chun
    • International Journal of Internet, Broadcasting and Communication
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    • 제14권1호
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    • pp.105-115
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    • 2022
  • The platform for displaying cars has been changing with the times. From the popularity of paper media to the rise of computer graphics, the improvement of technology has brought more space and possibilities to the automotive industry. Yiming Zhong proposed the workflow of car configurator through Unreal Engine 4 to implement the basic functions of configuration in 2021, according to Yiming Zhong's final presentation, there is still room to improve the realism of graphics and functionality of the car configurator. Therefore, in this paper we propose to upgrade the car shaders and lighting environments according to the real-world physics and add multi-scenes switching function to car configurator. However the multi-scenes switching function also brings a large amount of data, which leads to the problem of display lag. At the end of the paper, we use the level of details(LOD) process to reduce the amount of data for real-time computing in Unreal Engine 4 and the increase of frames per second(FPS) values verifies the feasibility of our optimization solution.

예비교사의 문제 생성과 재구성 활동에 관한 탐색 (An Investigation on the Application for Problem Generation and Problem Reformulation by Pre-service Teachers)

  • 김슬비;황혜정
    • 한국수학교육학회지시리즈E:수학교육논문집
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    • 제29권3호
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    • pp.533-551
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    • 2015
  • 본 연구에서는 '동일한' 문제 조건으로부터 생성과 재구성을 모두 경험할 수 있는 문제제기 활동을 적용하되, 활동을 세분화하여 학생들의 자주적인 활동을 강조한 활동과 학생들의 보편적 사고를 유도하며 교사 안내가 수반되는 활동으로 구분하여 이에 대한 두 절차를 구안하고, 이 두 활동에 의거하여 문제생성과 재구성 활동에 관해 탐색하고자 한다. 이를 위하여, 본 연구에서는 예비교사들을 대상으로 연구자가 구안한 문제제기 활동을 적용한 실험 수업 후 설문조사를 통하여 문제생성과 재구성에 대한 난이도 및 흥미도, 인지적 정의적 측면에서의 효과, 그리고 수학 수업 및 평가에서의 활용성 등을 탐색하였다. 그 결과, 문제생성은 창의력을 증진시키고 수학에 대한 흥미를 유발하며, 문제 재구성은 문제 해결력 향상에 도움이 되고 자신감을 길러주는 것으로 나타났다. 또한 수업 상황에서는 문제생성 활동이 더 효과적이고, 평가 상황에서는 문제재구성 활동이 더 효과적인 것으로 나타났으나 각 상황에서 문제생성과 재구성에 대한 응답의 차이가 크지 않았으므로 두 활동 모두 수업 및 평가에 적용이 가능할 것으로 판단된다. 따라서 교사는 학습자의 수준, 가르칠 영역, 진도 등을 고려하여 수업 및 평가 상황에서 문제생성과 재구성 활동을 적절한 시기에 알맞게 적용함으로써 학습자의 인지적, 정의적 성취의 함양을 돕도록 해야 할 것이다.

탐구 지향 미분방정식의 개발 실제: 교수실험을 통한 접근 (An Inquiry-Oriented Approach to Differential Equations: Contributions to Teaching University Mathematics through Teaching Experiment Methodology)

  • 권오남
    • 한국수학교육학회지시리즈E:수학교육논문집
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    • 제19권4호
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    • pp.733-767
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    • 2005
  • During the past decades, there has been a fundamental change in the objectives and nature of mathematics education, as well as a shift in research paradigms. The changes in mathematics education emphasize learning mathematics from realistic situations, students' invention or construction solution procedures, and interaction with other students of the teacher. This shifted perspective has many similarities with the theoretical . perspective of Realistic Mathematics Education (RME) developed by Freudental. The RME theory focused the guide reinvention through mathematizing and takes into account students' informal solution strategies and interpretation through experientially real context problems. The heart of this reinvention process involves mathematizing activities in problem situations that are experientially real to students. It is important to note that reinvention in a collective, as well as individual activity, in which whole-class discussions centering on conjecture, explanation, and justification play a crucial role. The overall purpose of this study is to examine the developmental research efforts to adpat the instructional design perspective of RME to the teaching and learning of differential equation is collegiate mathematics education. Informed by the instructional design theory of RME and capitalizes on the potential technology to incorporate qualitative and numerical approaches, this study offers as approach for conceptualizing the learning and teaching of differential equation that is different from the traditional approach. Data were collected through participatory observation in a differential equations course at a university through a fall semester in 2003. All class sessions were video recorded and transcribed for later detailed analysis. Interviews were conducted systematically to probe the students' conceptual understanding and problem solving of differential equations. All the interviews were video recorded. In addition, students' works such as exams, journals and worksheets were collected for supplement the analysis of data from class observation and interview. Informed by the instructional design theory of RME, theoretical perspectives on emerging analyses of student thinking, this paper outlines an approach for conceptualizing inquiry-oriented differential equations that is different from traditional approaches and current reform efforts. One way of the wars in which thus approach complements current reform-oriented approaches 10 differential equations centers on a particular principled approach to mathematization. The findings of this research will provide insights into the role of the mathematics teacher, instructional materials, and technology, which will provide mathematics educators and instructional designers with new ways of thinking about their educational practice and new ways to foster students' mathematical justifications and ultimately improvement of educational practice in mathematics classes.

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