• 제목/요약/키워드: fuzzy variables

검색결과 595건 처리시간 0.026초

일-가족 시간배분에 따른 가구유형과 변화 - 퍼지셋 이상형 분석의 적용 - (Household Types and Changes of Work-Family Time Allocation - Adapting Fuzzy-set Ideal Type Analysis -)

  • 김진욱;최영준
    • 한국사회복지학
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    • 제64권2호
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    • pp.31-54
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    • 2012
  • 본 연구는 생활시간조사자료를 활용하여 가구 내에서 배분되는 일-가족시간에 대한 실증분석을 수행하였다. 부부의 유급노동시간과 가족시간에서 차지하는 남성의 비중을 근거로 일-가족 시간 배분을 4개의 모형(전통적 남성생계부양, 이중노동부담, 협조적 적응, 가족친화적 남성생계부양)으로 유형화하였으며, 퍼지셋이상형분석을 통해 각 유형에 소속되어 있는 정도를 점수화한 후, 각 모형의 소속점수에 대한 중다회귀분석을 수행하였다. 연구결과, 지난 10년간 이중노동부담의 비중이 감소하고 협조적 적응 유형이 증가한 것으로 나타나고 있으나, 여전히 전체적인 모형별 분포를 보면 전통적인 성분업에 고착된 구조를 보여주고 있었다. 4개의 시간배분 모형에 대한 회귀분석 결과 역시 각 모형별 분석의 유용성을 보여주었으며, 무엇보다 성분업 의식의 역할은 제한적인 것으로 나타났다. 이를 바탕으로 향후 가족정책의 논의에 있어 가구내의 미시적 성분업 구조와 일-가족시간의 배분과 관련된 역동성을 좀 더 면밀히 파악할 필요가 있다는 점과, 방법론적 함의로 미시자료를 이용한 양적연구에서도 퍼지셋 활용이 방법론적 다양성을 제공해 줄 수 있다는 점을 논의하였다.

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무인선의 비전기반 장애물 충돌 위험도 평가 (Vision-Based Obstacle Collision Risk Estimation of an Unmanned Surface Vehicle)

  • 우주현;김낙완
    • 제어로봇시스템학회논문지
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    • 제21권12호
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    • pp.1089-1099
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    • 2015
  • This paper proposes vision-based collision risk estimation method for an unmanned surface vehicle. A robust image-processing algorithm is suggested to detect target obstacles from the vision sensor. Vision-based Target Motion Analysis (TMA) was performed to transform visual information to target motion information. In vision-based TMA, a camera model and optical flow are adopted. Collision risk was calculated by using a fuzzy estimator that uses target motion information and vision information as input variables. To validate the suggested collision risk estimation method, an unmanned surface vehicle experiment was performed.

Forecasting Using Interval Neural Networks: Application to Demand Forecasting

  • Kwon, Ki-Taek;Ishibuchi, Hisao;Tanaka, Hideo
    • 대한산업공학회지
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    • 제20권4호
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    • pp.135-149
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    • 1994
  • Demand forecasting is to estimate the demand of customers for products and services. Since the future is uncertain in nature, it is too difficult for us to predict exactly what will happen. Therefore, when the forecasting is performed upon the uncertain future, it is realistic to estimate the value of demand as an interval or a fuzzy number instead of a crisp number. In this paper, we propose a demand forecasting method using the standard back-propagation algorithm and then we extend the method to the case of interval inputs. Next, we demonstrate that the proposed method using the interval neural networks can represent the fuzziness of forecasting values as intervals. Last, we propose a demand forecasting method using the transformed input variables that can be obtained by taking account of the degree of influence between an input and an output.

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A study on intelligent fish-drying process control system

  • Nakamura, Makoto;Shiragami, Teizoh;Sakai, Yoshiro
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.132-137
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    • 1993
  • In this paper, a fish drying process control system is proposed, which predicts the proper change with time in weight of the material fish and the drying conditions in advance, based on the performance of skilled worker. In order to implement a human expertise into an automated fish drying process control system, an experimental analysis is made and a model for the process is built. The proposed system divided into two procedures: The procedure before drying and the one during drying. The procedure before drying is for the prediction of necessary drying time. To estimate the necessary drying time, first, the proper change in weight for the product is obtained by using fuzzy reasoning. The condition part of the production rule consists of the factors of fish body and the expected degree of dryness. Kext, the necessary drying time is obtained by regression models. The variables employed in the models are the factors, inferred change in weight and drying conditions. The model for the procedure during drying is also proposed for more accurate estimation, which is described by a system of linear-differential equations.

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Transformation of Mass Function and Joint Mass Function for Evidence Theory

  • Suh, Doug. Y.;Esogbue, Augustine O.
    • 한국지능시스템학회논문지
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    • 제1권2호
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    • pp.16-34
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    • 1991
  • It has been widely accepted that expert systems must reason from multiple sources of information that is to some degree evidential - uncertain, imprecise, and occasionally inaccurate - called evidential information. Evidence theory (Dempster/Shafet theory) provides one of the most general framework for representing evidential information compared to its alternatives such as Bayesian theory or fuzzy set theory. Many expert system applications require evidence to be specified in the continuous domain - such as time, distance, or sensor measurements. However, the existing evidence theory does not provide an effective approach for dealing with evidence about continuous variables. As an extension to Strat's pioneeiring work, this paper provides a new combination rule, a new method for mass function transffrmation, and a new method for rendering joint mass fuctions which are of great utility in evidence theory in the continuous domain.

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Hybrid Feature Selection Using Genetic Algorithm and Information Theory

  • Cho, Jae Hoon;Lee, Dae-Jong;Park, Jin-Il;Chun, Myung-Geun
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제13권1호
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    • pp.73-82
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    • 2013
  • In pattern classification, feature selection is an important factor in the performance of classifiers. In particular, when classifying a large number of features or variables, the accuracy and computational time of the classifier can be improved by using the relevant feature subset to remove the irrelevant, redundant, or noisy data. The proposed method consists of two parts: a wrapper part with an improved genetic algorithm(GA) using a new reproduction method and a filter part using mutual information. We also considered feature selection methods based on mutual information(MI) to improve computational complexity. Experimental results show that this method can achieve better performance in pattern recognition problems than other conventional solutions.

광류 정보를 이용한 이동 로봇의 장애물 회피 항법 (Obstacle Avoidance for a Mobile Robot Using Optical Flow)

  • 이한식;백준걸;장동식
    • 대한산업공학회지
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    • 제28권1호
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    • pp.25-35
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    • 2002
  • This paper presents a heuristic algorithm that a mobile robot avoids obstacles using optical flow. Using optical flow, the mobile robot can easily avoid static obstacles without a prior position information as well as moving obstacles with unknown trajectories. The mobile robot in this paper is able to recognize the locations or routes of obstacles, which can be detected by obtaining 2-dimensional optical flow information from a CCD camera. It predicts the possibilities of crash with obstacles based on the comparison between planned routes and the obstacle routes. Then it modifies its driving route if necessary. Driving acceleration and angular velocity of mobile robot are applied as controlling variables of avoidance. The corresponding simulation test is performed to verify the effectiveness of these factors. The results of simulation show that the mobile robot can reach the goal with avoiding obstacles which have variable routes and speed.

An Intelligent Fire Detection Algorithm for Fire Detector

  • Hong, Sung-Ho;Choi, Moon-Su
    • International Journal of Safety
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    • 제11권1호
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    • pp.6-10
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    • 2012
  • This paper presents a study on the analysis for reducing the number of false alarms in fire detection system. In order to intelligent algorithm fuzzy logic is adopted in developing fire detection system to reduce false alarm. The intelligent fire detection algorithm compared and analyzed the fire and non-fire signatures measured in circuits simulating flame fire and smoldering fire. The algorithm has input variables obtained by fire experiment with K-type thermocouple and optical smoke sensor. Also triangular membership function is used for inference rules. And the antecedent part of inference rules consists of temperature and smoke density, and the consequent part consists of fire probability. A fire-experiment is conducted with paper, plastic, and n-heptane to simulate actual fire situation. The results show that the intelligent fire detection algorithm suggested in this study can more effectively discriminate signatures between fire and similar fire.

퍼지-랜덤 변수를 이용한 실시간 전력 시스템의 성능 및 신뢰도 평가 (Evaluation of the Performance and Reliability of a Real-time Power System Described by a DES Model Using Fuzzy-Random Variables)

  • 민병조;김학배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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    • pp.794-796
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    • 1999
  • 엄격한 시간 제약성에 의해 특성화되는 실시간 전력 시스템의 성능 및 신뢰도를 평가하기 위해서 퍼지-랜덤 변수가 포함된 이산 사건 모델 및 확장된 path-space 기법을 제시한다. 실시간 시스템의 정확성은 출력의 논리적 결과 뿐 아니라 반응시간에도 의존하므로, 본 논문에서는 실시간 전력 시스템의 성능 및 신뢰도를 유연하게 평가하기 위해서 퍼지-랜덤 변수에 의해 적절하게 변형된 상태 오토마타를 제시하고 몇가지 수치 예제를 제시함으로써 제안한 기법의 효용성을 검증한다.

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ADAPTIVE, REAL-TIME TRAFFIC CONTROL MANAGEMENT

  • Nakamiti, G.;Freitas, R.
    • International Journal of Automotive Technology
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    • 제3권3호
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    • pp.89-94
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    • 2002
  • This paper presents an architecture for distributed control systems and its underlying methodological framework. Ideas and concepts of distributed systems, artificial intelligence, and soft computing are merged into a unique architecture to provide cooperation, flexibility, and adaptability required by knowledge processing in intelligent control systems. The distinguished features of the architecture include a local problem solving capability to handle the specific requirements of each part of the system, an evolutionary case-based mechanism to improve performance and optimize controls, the use of linguistic variables as means for information aggregation, and fuzzy set theory to provide local control. A distributed traffic control system application is discussed to provide the details of the architecture, and to emphasize its usefulness. The performance of the distributed control system is compared with conventional control approaches under a variety of traffic situations.