• Title/Summary/Keyword: imprecision

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The Spatial Fuzzy Approach to Multi-Criteria Decision Analysis for Flood Management (홍수터 관리 최적대안 결정을 위한 공간퍼지접근)

  • Lim, Kwang-Suop;Choi, Si-Jung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.1647-1651
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    • 2009
  • The uncertainty or imprecision associated with vague parameters and weighting sets, reduces the ability to decide what alternative is better for a particular location. To efficiently reduce the effect of imprecision frequently arising in available information, fuzzy theory has been used to improve consideration of imprecision in a Multi-Criteria Decision Analysis (MCDA) problem. Fuzzy logic offers a way to represent and handle imprecision present in continuous real world applications. A GIS implementing fuzzy set theory, (referred to in this paper as the "Spatial Fuzzy Approach") enables decision makers to express imprecise concepts associated with geographic data and provides decision makers the ability to have even more definition and discrimination in terms of the best alternatives for a particular spatial location. This study is focused on addressing questions pertaining to the methodology of floodplain analysis using GIS and Spatial Fuzzy MCDA to evaluate flood damage reduction alternatives. The issues will be examined in a case study of the Suyoung River Basin in Pusan, Korea.

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Soft computing with neural networks for engineering applications: Fundamental issues and adaptive approaches

  • Ghaboussi, Jamshid;Wu, Xiping
    • Structural Engineering and Mechanics
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    • v.6 no.8
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    • pp.955-969
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    • 1998
  • Engineering problems are inherently imprecision tolerant. Biologically inspired soft computing methods are emerging as ideal tools for constructing intelligent engineering systems which employ approximate reasoning and exhibit imprecision tolerance. They also offer built-in mechanisms for dealing with uncertainty. The fundamental issues associated with engineering applications of the emerging soft computing methods are discussed, with emphasis on neural networks. A formalism for neural network representation is presented and recent developments on adaptive modeling of neural networks, specifically nested adaptive neural networks for constitutive modeling are discussed.

Sequential Estimation with $\beta$-Protection of the Difference of Two Normal Means When an Imprecision Function Is Variable

  • Kim, Sung-Lai;Kim, Sung-Kyun
    • Journal of the Korean Statistical Society
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    • v.31 no.3
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    • pp.379-389
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    • 2002
  • For two normal distribution with unknown means and unknown variances, a sequential procedure for estimating the difference of two normal means which satisfies both the coverage probability condition and the $\beta$-protection is proposed under some smoothness of variable imprecision function, and the asymptotic normality of the proposed stopping time after some centering and scaling is given.

Analysis of Mathematical Quality of Instruction between Preservice and Inservice Mathematics Teachers (MQI를 이용한 예비교사와 현직교사의 수학수업의 질 분석)

  • Kim, Seong-Kyeong
    • The Mathematical Education
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    • v.55 no.4
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    • pp.397-416
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    • 2016
  • This study analyzed the quality of mathematics classes with observations using the instrument, MQI(Mathematical Quality of Instruction). Class recordings and interviews were conducted on 2 pre-service teachers and 4 in-service teachers. This study recorded and analyzed 3 or 4 classes for each mathematics teacher by using revised MQI. There were a total of 8 raters: 2 or 3 raters analyzed each class. MQI has four dimensions: Richness of the Mathematics, Working with Students and Mathematic, Errors and Imprecision, Student Participation in Meaning-Making and Reasoning. In the dimension of 'Richness of Mathematics', all teachers had good scores of 'explanations of teacher' but had lower scores of 'linking and connections', 'multiple procedures or solution methods' and 'developing mathematical generalizations.' In the dimension of 'Working with Students and Mathematics', two in-service teachers who have worked and having more experience had higher scores than others. In the dimension of 'Errors and Imprecision', all teachers had high scores. In the dimension of 'Student Participation in Meaning-Making and Reasoning', two pre-service teachers had contrast and also two in-service teachers who hadn't worked not long had contrast. Implications were deducted from finding to improving quality of mathematics classes.

Comparative Analysis on Imprecision Probability Under Several Imprecise Scheduling Schemes in Real Time Systems (실시간 시스템에서 여러 부정확한 스케쥴링 기법하에서의 부정확한 확률에 관한 비교 분석)

  • Ah, Gwl-Im;Koh, Kern
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.7
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    • pp.1304-1320
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    • 1994
  • There are two computation techniques in real time systems : precise and imprecise computation. The imprecise computation technique is a means to provide scheduling flexibility in real time systems. The studies on imprecise scheduling using queueing theoretical formulation up to data are to explicitly quantify the costs and benifits in trade-off between the average result quality and the average waiting time of tasks. This paper uses two imprecise scheduling schemes and solves the imprecision probability, the probability of any task being imprecise under two imprecise scheduling schemes and analyzes the dependence of the imprecision probability on several parameters os the monotone imprecise system.

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A Bottleneck-Based Production Scheduling under Fuzzy Environment (퍼지 환경하에서 품질수준 확보를 위한 일정계획에 관한 연구 -Bottleneck을 고려한 생산라인에서-)

  • Lee, Sang Wan;Shin, Dae Hyuk
    • Journal of Korean Society for Quality Management
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    • v.23 no.3
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    • pp.156-166
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    • 1995
  • Job shop scheduling problem is a complex system and an NP-hard problem. Thus it is natural to look for heuristic method. We consider the multi-part production scheduling problem for quality level in a job shop scheduling under the existence of alternative routings. The problem is more complex if the processing time is imprecision. It requires suitable method to deal with imprecision. Fuzzy set theory can be useful in modeling and solving scheduling problems with uncertain processing times. Li-Lee fuzzy number comparison method will be used to compare processing times that evaluated under fuzziness. This study presents heuristic method for quality level in bottleneck-based job shop scheduling under fuzzy environment. On the basis of the proposed method, an example is presented.

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Design and Development of Gravure Offset Printing System (그라비아 옵셋 인쇄 장비 설계 및 제작)

  • Noh, Jae-Ho;Lee, Taik-Min;Park, Sang-Ho;Jo, Jeong-Dai;Kim, Dong-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.9
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    • pp.16-19
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    • 2010
  • This paper presents how to design and fabricate the gravure offset printing system for enhancement of register precision. Factors of precision error are caused by imprecision of gravure plate, deformation of substrate, printing quality change due to the change of ink viscosity, Imprecision of printing machine, and so on. This study suggests concept design of gravure offset printing system which is able to minimize or remove these error factors.

Different approaches towards fuzzy database systems A Survey

  • Rundensteiner, Elke A.;Hawkes, Lois Wright
    • Journal of the Korean Institute of Intelligent Systems
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    • v.3 no.1
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    • pp.65-75
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    • 1993
  • Fuzzy data is a phenomenon often occurring in real life. There is the inherent vagueness of classification terms referring to a continuous scale, the uncertainty of linguistic terms such as "I almost agree" or the vagueness of terms and concepts due to the statistical variability in communication [20] and many more. Previously, such fuzzy data was approximated by non-fuzzy (crisp) data, which obviously did not lead to a correct and precise representation of the real world. Fuzzy set theory has been developed to represent and manipulate fuzzy data [18]. Explicitly managing the degree of fuzziness in databases allows the system to distinguish between what is known, what is not known and what is partially known. Systems in the literature whose specific objective is to handle imprecision in databases present various approaches. This paper is concerned with the different ways uncertainty and imprecision are handled in database design. It outlines the major areas of fuzzification in (relational) database systems.

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