• 제목/요약/키워드: logical problem

검색결과 413건 처리시간 0.021초

Parameter identification for nonlinear behavior of RC bridge piers using sequential modified extended Kalman filter

  • Lee, Kyoung Jae;Yun, Chung Bang
    • Smart Structures and Systems
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    • 제4권3호
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    • pp.319-342
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    • 2008
  • Identification of the nonlinear hysteretic behavior of a reinforced concrete (RC) bridge pier subjected to earthquake loads is carried out based on acceleration measurements of the earthquake motion and bridge responses. The modified Takeda model is used to describe the hysteretic behavior of the RC pier with a small number of parameters, in which the nonlinear behavior is described in logical forms rather than analytical expressions. Hence, the modified extended Kalman filter is employed to construct the state transition matrix using a finite difference scheme. The sequential modified extended Kalman filter algorithm is proposed to identify the unknown parameters and the state vector separately in two steps, so that the size of the problem for each identification procedure may be reduced and possible numerical problems may be avoided. Mode superposition with a modal sorting technique is also proposed to reduce the size of the identification problem for the nonlinear dynamic system with multi-degrees of freedom. Example analysis is carried out for a continuous bridge with a RC pier subjected to earthquake loads in the longitudinal and transverse directions.

A Study of Construct Fuzzy Inference Network using Neural Logic Network

  • Lee, Jae-Deuk;Jeong, Hye-Jin;Kim, Hee-Suk;Lee, Malrey
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제5권1호
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    • pp.7-12
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    • 2005
  • This paper deals with the fuzzy modeling for the complex and uncertain nonlinear systems, in which conventional and mathematical models may fail to give satisfactory results. Finally, we provide numerical examples to evaluate the feasibility and generality of the proposed method in this paper. The expert system which introduces fuzzy logic in order to process uncertainties is called fuzzy expert system. The fuzzy expert system, however, has a potential problem which may lead to inappropriate results due to the ignorance of some information by applying fuzzy logic in reasoning process in addition to the knowledge acquisition problem. In order to overcome these problems, We construct fuzzy inference network by extending the concept of reasoning network in this paper. In the fuzzy inference network, the propositions which form fuzzy rules are represented by nodes. And these nodes have the truth values representing the belief values of each proposition. The logical operators between propositions of rules are represented by links. And the traditional propagation rule is modified.

Optimal synthesis for retrofitting heat exchanger network

  • Lee, In-Beum;Jung, Jae-Hak;Chang, Kun-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.1259-1264
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    • 1990
  • During the past two decades, a lot of researches have been done on the synthesis of grassroot heat exchanger networks(HEN). However, few have been dedicated to retrofit of existing heat exchanger networks, which usually use more amount of utilities (i.e. steam and/or cooling water) than the minimum requirements. This excess gives motivation of trades-off between energy saving and rearranging investment. In this paper, an algorithmic-evolutionary synthesis procedure for retrofitting heat exchanger networks is proposed. It consists of two stages. First, after the amount of maximum energy recovery(MER) is computed, a grass-root network featuring minimum number of units(MNU) is synthesized. In this stage, a systematic procedure of synthesizing MNU networks is presented. It is based upon the concept of pinch, from which networks are synthesized in a logical way by the heuristics verified by the pinch technology. In the second stage, since an initial feasible network is synthesized based on the pre-analysis result of MER and must-matches, an assignment problem between new and existing units is solved to minimize total required additional areas. After the existing units are assigned, the network can be improved by switching some units. For this purpose, an improvement problem is formulated and solved to utilize the areas of existing units as much as possible. An example is used to demonstrate the effectiveness of the proposed method.

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초등학교 컴퓨터교육에서 언플러그드 학습 방법을 활용한 정보표현 영역 교수.학습에 관한 연구 (A Study on Teaching-Learning about The Information Representation Area using Unplugged Learning Method in Elementary School Computer Education)

  • 박윤성;한병래
    • 정보교육학회논문지
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    • 제13권4호
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    • pp.479-487
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    • 2009
  • 현재 우리나라 컴퓨터 교육과정의 성격과 목표 중 가장 강조하는 부분은 정보소양 능력과 문제해결 능력을 배양하여 미래사회를 선도할 수 있는 능력을 키우는 것이다. 그러나 현행의 컴퓨터교육은 응용 프로그램 활용 교육에만 초점이 맞추어져 있어 이 목표를 달성하지 못하고 있으며 문제해결 능력과 논리적 사고력을 높이기 위해 컴퓨터과학 교육에 대한 중요성이 커지고 있다. 이에 본 연구에서는 언플러그드 학습 방법을 컴퓨터과학 영역 중의 정보표현 영역에 적용하였다. 그 결과 언플러그드 학습 방법이 강의식 학습 방법에 비해 학업성취도가 통계적으로 유의한 차이를 보이며 높게 나타났다. 또한 정의적 영역에서도 강의식 학습 방법에 비해 긍정적으로 나타났다.

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창조적(創造的) 패션디자인 프로세스에 관(關)한 연구(硏究) (A Study on Creative Fashion Design Processes)

  • 오나영;이승희
    • 패션비즈니스
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    • 제11권2호
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    • pp.129-144
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    • 2007
  • These days, public attention is being directed to the design processes by which a final outcome can be produced to achieve its goal according to the logical plans, as it is hard to address recent problems in design by the existing intuitive way due to the paradigm shift of design. Thus, this study aims to suggest creative fashion design processes to create a product as a final outcome by intentional and systematic processes. This study showed that design is considered as comprehensive problem solving processes, and it proposes framework of processes by integrating processes of industrial design and fashion design. In addition, this study classified creativity development methods that can be implemented to fashion design into promotion of ideas, breaking out of stereotypes, and extension of search areas. These creativity development methods can be applied to fashion design processes in order to make plans and strategies systematically and help you to choose the best ways to solve problems by processes.

공업계 고등학교 학생들의 직업기초능력의 수준과 개선 방안 (A Study on the Key Competencies of Industrial High School Students and Some Way of their Improvement)

  • 안광식;배동윤;박락영;최완식
    • 대한공업교육학회지
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    • 제30권2호
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    • pp.3-11
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    • 2005
  • The purpose of this study is to measure the level of the key competencies of industrial high school students and to use it as the basic material so as to improve the key competencies. The subject was 359 industrial high school students(boys: 244, girls: 115) in Seoul, Daejeon, Gwangju, and Busan. The instrument used to measure the key competencies is that developed by Cheol-Young Jeong, which was partly revised with the help of a group of experts. The results of this study showed some of skills were below an average of 3.0, which were writting skill(M=2.85) and speaking skill(M=2.96) in communication skills, logical thinking(M=2.98) in problem solving skills, leadership skill(M=2.88) in interpersonal skills, and self-improvement skill(M=2.96) and the spirit of public service(M=2.93) in self-management and self-improvement skills. But technology skills were above an average of 3.0. And it appeared that technology skills(P=.023) depended on having a certificate or not, and so did communication skills(P=.020) and problem solving skills(P=.034) on the types of a course(employment or entrance into a college). So, to strengthen the key competencies which appeared below an average of 3.0 in this study, not only does the curriculum of industrial high schools need to be reorganized, but systematic strengthening program of key competencies should also be developed.

SAT 처리기를 위한 수도쿠 퍼즐의 최적화된 인코딩 (Optimized Encoding of Sudoku Puzzle for SAT Solvers)

  • 권기현
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제34권7호
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    • pp.616-624
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    • 2007
  • SAT을 이용해서 수도쿠 퍼즐을 풀기 위해서는 수도쿠를 SAT 처리기의 표준 입력 언어인 CNF 논리식으로 인코딩 해야 한다. 기존에 제시된 인코딩 알고리즘으로 크기가 큰 수도쿠를 인코딩하면 현재 SAT 처리기의 처리 수준을 넘을 정도로 많은 논리식이 생성된다. 본 논문에서는 크기가 큰 수도쿠를 다루기 위해서 수도쿠의 고정 셀을 이용하여 최적화된 CNF 논리식을 생성하는 방법을 제시한다. 고정 셀에 배정된 숫자는 불변이기 때문에 이를 이용해서 일부 변수의 값을 인코딩 단계에서 미리 결정할 수 있고, 이들 변수의 값을 이용해서 SAT 처리에 영향을 주지 않는 절과 리터럴을 인코딩 단계에서 제거할 수 있다. 다양한 크기의 수도쿠 퍼즐에 적용한 결과 기존 인코딩 알고리즘에 비해서 우수한 성능을 보였다.

전공계열별 인공지능 교양교육을 위한 교육과정 제언 : D대학 교양필수 교과목 사례를 중심으로 (A Research on Curriculum Design for Artificial Intelligence Liberal Arts Education by Major Category : Focusing on the Case of D University)

  • 박소현;서응교
    • 한국정보시스템학회지:정보시스템연구
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    • 제30권3호
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    • pp.177-199
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    • 2021
  • Purpose This study explores the development direction of the artificial intelligence curriculum as a universal education that enhances the ability of college students to flexibly use artificial intelligence these days, where artificial intelligence education is spreading, and the educational components based on this are subdivided according to the characteristics of each major. Design/methodology/approach In order to develop the educational purpose of the subject and the detailed educational curriculum suitable for the subject of education, we first analyzed domestic and foreign prior research related to artificial intelligence liberal arts education. As the main components derived by experts, the basic concept of artificial intelligence converges to literacy to read and write for everyday problem solving, as well as problem-solving ability to manipulate real data and software. Findings The results showed that In the artificial intelligence literacy module, trends and prospects of artificial intelligence and necessary competencies were checked, and cases applied to major fields were examined. In the AI utilization and application part, basic data analysis items and content composition were composed through creative thinking, logical thinking, and intelligence. In order to design the curriculum, a software development language suitable for each major area was first selected, and AI education content areas, elements, and packages were defined and designed for each major area to meet the objectives of the subject.

중국 의무교육단계 학생 부담경감 정책의 흐름 분석 - Kingdon의 정책흐름모형을 중심으로 (An Analysis on Student Burden Double Reduction Policy in China - Based on Kingdon's Policy Stream Model)

  • 이효휘
    • 국제교류와 융합교육
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    • 제4권1호
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    • pp.35-56
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    • 2024
  • 이 연구는 중국 의무교육단계 학생 부담경감 최신정책 '쌍감'정책을 중심으로 Kingdon의 정책흐름모형을 활용하여 정책의 흐름을 분석하였다. 데이터의 직관적인 반영, 현행 정책의 피드백 등으로 문제의 흐름을 구성하였다. 중국 정부의 높은 관심, 정치협상회의 위원과 전문가의 건언, 학교 현장과 이해관계자의 강한 요구 등은 정책대안의 흐름을 구성하였다. 집권당의 집권 이념과 교육 지침, 국민 정서, 전환기 이익 게임 등은 정치의 흐름을 구성한 것이다.문제의 흐름,정책대안의 흐름, 정치의 흐름 세 가지 흐름이 결합되어 '정책의 창'이 열리게 된 것으로 분석되었다.

융합 사고와 화학문제풀이 과정에서의 두뇌 활성 양상과 기능적 연결성 (Brain Activation Pattern and Functional Connectivity during Convergence Thinking and Chemistry Problem Solving)

  • 권승혁;오재영;이영지;엄증태;권용주
    • 대한화학회지
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    • 제60권3호
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    • pp.203-214
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    • 2016
  • 본 연구는 창의적 문제해결능력의 향상에 필수적인 융합 사고의 특성을 알아보기 위해 기능적 자기공명영상을 이용하여 창의적 문제해결에 기반한 융합 사고와 화학문제풀이를 하는 동안의 두뇌 활성 영역과 기능적 연결성을 알아보았다. 이를 위하여 시각 기반의 융합 사고 유발 과제와 화학문제풀이 과제를 개발하고 고등학생 17명을 대상으로 적용하여 과제 수행 동안의 두뇌활성영상을 분석하였다. 연구 결과, 융합 사고 시에는 두뇌 좌측의 상전두이랑, 중전두이랑, 하전두이랑, 내측전두이랑, 전대상이랑, 쐐기전소엽, 미상핵체에서 두뇌 우측의 쐐기소엽, 미상핵체에서 활성이 나타났다. 화학 문제풀이에서는 두뇌 좌측의 중전두이랑, 내측전두이랑, 미상핵체, 미상핵꼬리에서 두뇌 우측의 중전두이랑, 혀이랑, 미상핵체, 미상핵꼬리, 시상, 소뇌정상에서 활성이 나타났다. 기능적 연결성분석 결과 융합 사고 시에는 각 활성 영역들이 모두 기능적 연결망을 형성하고 있는 것으로 나타났으며 이와 대조적으로 화학문제풀이 시에는 우측 중전두이랑, 좌우측미상핵꼬리, 소뇌정상만이 기능적 연결망을 형성한 것으로 나타났다. 이러한 결과는 고등학생들이 융합 사고 시에 논리적 사고, 작업기억활성, 계획, 상상, 언어화, 학습동기 유발이 일어나며 이러한 기능들이 과제를 수행하는 동안 서로 밀접하게 동조하고 있음을 보여준다. 반면 화학문제풀이 시에는 논리적 사고와 계획, 비교, 학습동기유발의 기능들을 수행하지만 각영역들이 동시에 활발히 작용하지 못하는 것을 보여준다. 이러한 결과는 융합 사고에 대한 구체적인 정보를 제공할 수 있을 것이다.