• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제15권5호
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• pp.370-374
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• 2009

본 논문에서는 IEEE 802.16 OFDMA 시스템에서 QoS를 제공해 주기 위해서 표준에서 정의해 놓은 서비스 클래스 별 대역폭 할당 기법 중에서 UGS 클래스의 대역폭 할당 기법에서의 문제점을 지적하고 이를 해결하기 위한 알고리즘을 제시한다. 802.16 시스템에서는 다섯 가지 트래픽 클래스를 정의하고 이 중에서 UGS 클래스의 서비스 우선 순위를 가장 높게 처리하고 있다. 하지만, 기존의 UGS 클래스를 위한 대역폭 할당 방식에서는 다수개의 UGS 클래스가 존재할 때의 대역폭 할당 주기가 겹치는 문제에 대한 고려를 하고 있지 않다. 이로 인해서 오히려 UGS 클래스의 QoS 서비스를 제공해 줄 수 없는 상황이 발생하게 된다. 본 논문에서는 이런 문제점의 발생을 성능측정을 통해서 보여 주고 이를 해결하기 위한 알고리즘을 제시한다. 또한, 성능 비교를 통해서 제안하는 알고리즘 적용 시에 성능 향상이 있음을 보여 주고자 한다. 본 알고리즘의 적용을 통해서 실제 시스템 적용 시에 발생할 수 있는 문제점을 해결함으로써 보다 안정적인 QoS 서비스를 제공할 수 있는 802.16 시스템이 되리라 기대한다.

• 한국지능시스템학회:학술대회논문집
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• 한국지능시스템학회 2008년도 춘계학술대회 학술발표회 논문집
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• pp.127-128
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• 2008

In this paper, we consider define fuzzy invex sets and fuzzy preinvex functions on the class of Choquet integrable functions, and interval-valued fuzzy invex sets and interval-valued fuzzy preinvex functions on the class of interval-valued Choquet integrals. And also we prove some properties of them.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.163-164
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• 2011

본고에서는 Multi-class Jobs을 Dispatching system 에서 처리하는 경우, Cost performance 을 점근적으로 해석하는 과정에 대해 논의한다. 구체적으로, Job 할당 시스템은 Size-Interval 기반의 스케줄링 기법을 이용하고, Resource failure 에 대비하여 Job duplication 전략을 활용하는 것으로 가정 한다.

• Journal of the Korean Data and Information Science Society
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• 제11권2호
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• pp.173-179
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• 2000

Interval prediction based on the empirical distribution function for the class of time series with time varying coefficients is discussed. To this end, strong mixing property of the model is shown and results due to Fotopoulos et. al.(1994) are employed. A simulation study is presented to assess the accuracy of the proposed interval predictor.

• 대한산업공학회지
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• 제41권5호
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• pp.439-446
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• 2015

Recently, the importance of one-class classification problem is more increasing. However, most of existing algorithms have the limitation on providing the information that effects on the prediction of the target value. Motivated by this remark, in this paper, we suggest an efficient one-class classifier using hyper-rectangles (H-RTGLs) that can be produced from intervals including observations. Specifically, we generate intervals for each feature and integrate them. For generating intervals, we consider two approaches : (i) interval merging and (ii) clustering. We evaluate the performance of the suggested methods by computing classification accuracy using area under the roc curve and compare them with other one-class classification algorithms using four datasets from UCI repository. Since H-RTGLs constructed for a given data set enable classification factors to be visible, we can discern which features effect on the classification result and extract patterns that a data set originally has.

• 동력기계공학회지
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• 제10권4호
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• pp.99-104
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• 2006

Young's modulus of composite has been predicted by Eshelby's equivalent inclusion method modified with Mori-Tanaka's mean field theory, where short fibers of aspect ratio distribution are assumed to be aligned. Young's modulus of the composite is predicted with the smallest class interval for simulating the actual distribution of fiber aspect ratio, which is compared with that computed using different class intervals. Young's modulus of the composite predicted with mean aspect ratio or the largest class interval is overestimated by the maximum 10%. As the class interval of short fibers for predicting Young's modulus decreases, the predicted results show good agreements with those obtained using the actual distribution of fiber aspect ratio. It can be finally concluded from the study that if and only if the class interval of short fiber normalized by the maximum aspect ratio is smaller than 0.1, the predicted results are consistent with those obtained using the actual distribution of aspect ratio.

• Communications for Statistical Applications and Methods
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• 제16권2호
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• pp.363-372
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• 2009

The difference of two independent binomial proportions is frequently of interest in biomedical research. The interval estimation may be an important tool for the inferential problem. Many confidence intervals have been proposed. They can be classified into the class of exact confidence intervals or the class of approximate confidence intervals. Ore may prefer exact confidence interval s in that they guarantee the minimum coverage probability greater than the nominal confidence level. However, someone, for example Agresti and Coull (1998) claims that "approximation is better than exact." It seems that when sample size is large, the approximate interval is more preferable to the exact interval. However, the choice is not clear when sample, size is small. In this note, an exact confidence and an approximate confidence interval, which were recommended by Santner et al. (2007) and Lee (2006b), respectively, are compared in terms of the coverage probability and the expected length.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권1호
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• pp.66-70
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• 2007

Note that Choquet integral is a generalized concept of Lebesgue integral, because two definitions of Choquet integral and Lebesgue integral are equal if a fuzzy measure is a classical measure. In this paper, we consider interval-valued Choquet integrals with respect to fuzzy measures(see [4,5,6,7]). Using these Choquet integrals, we define a mappings on the classes of Choquet integrable functions and give an example of a mapping defined by interval-valued Choquet integrals. And we will investigate some relations between m-convex mappings ${\phi}$ on the class of Choquet integrable functions and m-convex mappings $T_{\phi}$, defined by the class of closed set-valued Choquet integrals with respect to fuzzy measures.

• 전자공학회논문지B
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• 제32B권10호
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• pp.1259-1268
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• 1995

This note presents the robust root clustering problem of interval systems whose characteristic equation might be given as either a family of interval polynomials or a family of polytopes. Corresponding to damping ratio and robustness margin approximately, we consider a certain class of D-region such as parabola, left-hyperbola, and ellipse in complex plane. Then a simpler D-stability criteria using rational function mapping is presented and prove. Without .lambda. or .omega. sweeping calculation, the absolute criteria for robust D-stability can be determined.

• Journal of applied mathematics & informatics
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• 제27권3_4호
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• pp.581-589
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• 2009

In this paper, we are concerned with a class of nonlinear second-order differential equations with a nonlinear damping term and forcing term: $$(r(t)k_1(x(t),x'(t)))'+p(t)k_2(x(t),x'(t))x'(t)+q(t)f(x(t))=0$$. Passage to more general class of equations allows us to remove a restrictive condition usually imposed on the nonlinearity. And, as a consequence, our results apply to wider classes of nonlinear differential equations. Some illustrative examples are considered.