• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 춘계학술대회 학술발표 논문집
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• pp.136-139
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• 2001

This paper develops a sensor based navigation method that utilizes fuzzy logic and the Dempster-Shafer evidence theory for mobile robot in uncertain environment. The proposed navigator consists of two behaviors: obstacle avoidance and goal seeking. To navigate reliably in the environment, we make a map building process before the robot finds a goal position and create a robust fuzzy controller. In this paper, the map is constructed on a two-dimensional occupancy grid. The sensor readings are fused into the map using D-S inference rule. Whenever the robot moves, it catches new information about the environment and replaces the old map with new one. With that process the robot can go wandering and finding the goal position. The usefulness of the proposed method is verified by a series of simulations. 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.

• 한국지능시스템학회논문지
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• 제8권4호
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• pp.69-72
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• 1998

We introduce a concept of a 'fuzzy' map between sets by modifying the concetp of the extension principle introduced by Dubois and Prade in [1] and by using this we generalize Goguen's and Zadeh's extension principles in [2] and [3].

• 한국BIM학회 논문집
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• 제8권4호
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• pp.72-79
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• 2018

Rapid developments around the world have resulted in urban expansion, habitat destruction, habitat fragmentation, and pollution problems, which are the main reasons for the decline in biological diversity. The United Nations warns that many animals and plants will die out in the near future if this continues. This study was performed to propose a map of eco-corridor suitability analysis of Korean water deer(Hydropotes Inermis) to enhance biodiversity in Chuncheon city. Eight factors affecting habitat suitability were elevation, aspect, slope, forest type, distance to the road, distance to the stream, land use and green connectivity. Previous study analysis on the mobility behaviour of the Korean water deer(Hydropotes Inermis) produced a habitat suitability map by determining the threshold and assigning a value between 0 and 1 depending on the habitat suitability using the fuzzy function. A method of analysis was proposed for a number of eco-corridor through comparative analysis of the data from the produced habitat suitability map and the road-kill point. The previous studies were focused on Backdudaegan region and national parks except for urban cities. The potential habitat map of Korean water deer could be helpful as a way to prevent habitat disconnection and increase species diversity in urban areas.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제14권3호
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• pp.223-230
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• 2007

We give an answer to the following question: Question. Let S be a subset of [0,1] containing a maximal element m > 0 and let C :=$\{I_{t}\;{\mid}\;t{\in}S\}$ be a decreasing chain of ideals of a BCK/BCI-algebra X. Then does there exists a fuzzy ideal ${\mu}(X)=S\;and\;C_{\mu}=C?$.

• Transactions on Control, Automation and Systems Engineering
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• 제1권1호
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• pp.54-61
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• 1999

FCM(Fuzzy Cognitive Map) is proposed for representing causal reasoning. Its structure allows systematic causal reasoning through a forward inference. By using the FCM, authors have proposed FCM-based fault diagnostic algorithm. However, it can offer multiple interpretations for a single fault. In process engineering, as experience accumulated, some form of quantitative process knowledge is available. If this information can be integrated into the FCM-based fault diagnosis, the diagnostic resolution can be further improved. The purpose of this paper is to propose an enhanced FCM-based fault diagnostic scheme. Firstly, the membership function of fuzzy set theory is used to integrate quantitative knowledge into the FCM-based diagnostic scheme. Secondly, modified TAM recall procedure is proposed. Considering that the integration of quantitative knowledge into FCM-based diagnosis requires a great deal of engineering efforts, thirdly, an automated procedure for fusing the quantitative knowledge into FCM-based diagnosis is proposed by utilizing self-learning feature of neural network. Finally, the proposed diagnostic scheme has been tested by simulation on the two-tank system.

• 제어로봇시스템학회논문지
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• 제12권6호
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• pp.554-560
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• 2006

In this paper, we propose the topological map building method about unknown environment using the ultrasonic sensors. An ultrasonic sensor inherently has the range error due to the specular reflection. To decrease this error, we estimate the obstacle states(position and velocity) using the local minimum sensor values and Jacobian. Estimated states are used to avoid the obstacles and build the topological map similar to the type that human being memorizes an environment. When a mobile robot is faced with three problems(comer way, cross way and dead end), it senses the movable directions using FIS(Fuzzy Inference System). Among these directions, it can select the target direction using binary decision tree(Turn Side Selector). Proposed algorithm has been verified with three simulations and three implementations.

• 한국지형학회지
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• 제23권2호
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• pp.109-125
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• 2016

This study aims to identify the landslide susceptible zones of Boeun area and provide reliable landslide susceptibility maps by applying different modeling methods. Aerial photographs and field survey on the Boeun area identified landslide inventory map that consists of 388 landslide locations. A total ofseven landslide causative factors (elevation, slope angle, slope aspect, geology, soil, forest and land-use) were extracted from the database and then converted into raster. Landslide causative factors were provided to investigate about the spatial relationship between each factor and landslide occurrence by using fuzzy set and logistic regression model. Fuzzy membership value and logistic regression coefficient were employed to determine each factor's rating for landslide susceptibility mapping. Then, the landslide susceptibility maps were compared and validated by cross validation technique. In the cross validation process, 50% of observed landslides were selected randomly by Excel and two success rate curves (SRC) were generated for each landslide susceptibility map. The result demonstrates the 84.34% and 83.29% accuracy ratio for logistic regression model and fuzzy set model respectively. It means that both models were very reliable and reasonable methods for landslide susceptibility analysis.

• 대한수학회논문집
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• 제22권3호
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• pp.391-399
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• 2007

The purpose of this paper is to obtain some common fixed point theorems for multivalued mappings in intuitionistic fuzzy metric space. We extend some earlier results.

• 대한수학교육학회지:수학교육학연구
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• 제14권3호
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• pp.239-266
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• 2004

본 연구는 기존의 수학적 오류에 대한 연구들이 취했던 학생들의 현재 상태를 바탕으로 다양한 오류를 분석하는 방식이 아니라, 학생들의 문제해결과정에서 나타나는 수학적 오류를 인지심리학의 관점에서 분석가능한지를 탐색하는 것을 목적으로 한다. 이에, 본 연구는 Pauscal-Leone의 신피아제 이론을 중심으로 Schoenfeld의 구조 분석 단계(levels of analysis and structure)모형과 개념적, 인과적 관계의 이해를 형식화하는 도구로서 퍼지 인지 맵(Fuzzy Cognitive Map)을 활용하여 학생들의 증명 문제해결 과정에서 나타나는 오류를 분석하고 오도요인을 진단하였다. 연구 결과, 주어진 명제에서 정보를 해석할 때 F조작자가 강하게 활성화되어 나타나는 오도 요인으로 인하여 학생들은 증명에 필요한 개념노드를 충분하게 인출하지 못하거나 인과관계가 없는 개념노드를 나름대로 논리적으로 연결하여 잘못된 증명을 하고 있었다. 오류와 관련된 인지구조는 학생 나름대로의 논리적 알고리듬에 의한 LC 학습의 결과로 형성된 LC 학습구조로 볼 수 있다.

• 대한수학회논문집
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• 제9권3호
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• pp.687-700
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• 1994

Throughout this paper we will let H denote the complete Heyting algebra ($H, \vee, \wedge, *$) with order reversing involution *. 0 and 1 denote the supermum and the infimum of $\emptyset$, respectively. Given any set X, any element of $H^X$ is called H-fuzzy set (or, simply f.set) in X and will be denoted by small Greek letters, such as $\mu, \nu, \rho, \sigma$. $H^X$ inherits a structure of H with order reversing involution in natural way, by definding $\vee, \wedge, *$ pointwise (sam notations of H are usual). If $f$ is a map from a set X to a set Y and $\mu \in H^Y$, then $f^{-1}(\mu)$ is the f.set in X defined by f^{-1}(\mu)(x) = \mu(f(x))$. Also for $\sigma \in H^X, f(\sigma)$ is the f.set in Y defined by $f(\sigma)(y) = sup{\sigma(x) : f(x) = y}$ ([4]). A preorder R on a set X is reflexive and transitive relation on X, the pair (X,R) is called preordered set. A map $f$ from a preordered set (X, R) to another one (Y,T) is said to be preorder preserving (inverting) if for $x,y \in X, xRy$ implies $f(x)T f(y) (resp. f(y)Tf(x))$. For the terminology and notation, we refer to [10, 11, 13] for category theory and [7] for H-fuzzy semitopogenous spaces.