• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.4
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• pp.445-450
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• 2008

In order to analyze the reliabilities of the fuzzy systems, the reliabilities of the components in the fuzzy systems are represented by real values between zero and one, fuzzy numbers, intervals of confidence, vague sets, interval valued fuzzy sets, etc in the conventional researches. In this paper, we propose a method to represent and analyze the reliabilities of the fuzzy systems based on the interval valued vague sets defined in the universe of discourse [0, 1]. In the interval valued vague sets, the upper bounds and the lower bounds of the conventional vague sets[12, 14] are represented as the intervals. Therefore, it can allow the reliabilities of a fuzzy system to represent and analyze in a more flexible manner. Because the proposed method uses the simplified arithmetic operations of the fuzzy triangular numbers rather than the complicated of the fuzzy trapezoidal numbers mentioned by Kumar[14], the execution of the proposed method is faster than the one.

• Asia-Pacific Journal of Business
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• v.4 no.2
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• pp.41-53
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• 2013

Undoubtedly, the basic sinking fund formula gives the future value of a series of equal installments. The main underlying assumption for using this formula is that installment and compounding frequency must be in equal interval. But when installment for a deposit scheme or any other savings scheme and compounding frequency do not occur in an equal interval, which is treated as the complex annuity problems in Finance Literature, the basic sinking fund formula does not give the accurate result. As a result, the obtainable amount from different deposit schemes offered by different banks and financial institutions does not match with the amount of future value calculated through the basic sinking fund formula by the investors or savers. This study focuses the concealed facts for such type of mismatches in values and at the same time it provides a solution through developing a new formula by extending the basic formula intended not only to remove those mismatches but also get the accurate future value from a sinking fund provision in case of complex annuity. Besides, since banks and financial institutions calculate the interest on the average amount of equal installments deposited within a period of time due to complex annuity, the study also formulates an arithmetic formula for calculating the average amount of installment.

• Convergence Security Journal
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• v.7 no.2
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• pp.49-55
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• 2007

Software failure time presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing. For data analysis of software reliability model, data scale tools of trend analysis are developed. The methods of trend analysis are arithmetic mean test and Laplace trend test. Trend analysis only offer information of outline content. From the subdivision of this analysis, new attemp needs the side of the quality control. In this paper, we discuss process capability analysis using process capability indexs. Because of software failure interval time is pattern of nonnegative value, instead of capability analysis of suppose to normal distribution, capability analysis of process distribution using to Box-Cox transformation is attermpted. The used software failure time data for capability analysis of process is SS3, the result of analysis listed on this chapter 4 and 5. The practical use is presented.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.6
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• pp.804-806
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• 2007

The usual arithmetic operations on real numbers can be extended to arithmetical operations on fuzzy intervals by means of Zadeh's extension principle based on a t-norm T. Dombi and Gyorbiro proved that addition is closed if the Dombi t-norm is used with two bell-shaped fuzzy intervals. Recently, Hong [Fuzzy Sets and Systems 158(2007) 739-746] defined a broader class of bell-shaped fuzzy intervals. Then he study t-norms which are consistent with these particular types of fuzzy intervals as applications of a result proved by Mesiar on a strict f-norm based shape preserving additions of LR-fuzzy intervals with unbounded support. In this note, we give a direct proof of the main results of Hong.

• Bulletin of the Korean Mathematical Society
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• v.51 no.6
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• pp.1829-1839
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• 2014

Let (${\Omega}$, $\mathcal{S}$, ${\mu}$) be a probabilistic measure space, ${\varepsilon}{\in}\mathbb{R}$, ${\delta}{\geq}0$, p > 0 be given numbers and let $P{\subset}\mathbb{R}$ be an open interval. We consider a class of functions $f:P{\rightarrow}\mathbb{R}$, satisfying the inequality $$f(EX){\leq}E(f{\circ}X)+{\varepsilon}E({\mid}X-EX{\mid}^p)+{\delta}$$ for each $\mathcal{S}$-measurable simple function $X:{\Omega}{\rightarrow}P$. We show that if additionally the set of values of ${\mu}$ is equal to [0, 1] then $f:P{\rightarrow}\mathbb{R}$ satisfies the above condition if and only if $$f(tx+(1-t)y){\leq}tf(x)+(1-t)f(y)+{\varepsilon}[(1-t)^pt+t^p(1-t)]{\mid}x-y{\mid}^p+{\delta}$$ for $x,y{\in}P$, $t{\in}[0,1]$. We also prove some basic properties of such functions, e.g. the existence of subdifferentials, Hermite-Hadamard inequality.

• Korean Journal of Computational Design and Engineering
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• v.17 no.4
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• pp.262-273
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• 2012

We present a novel GPU algorithm to compute outer cell boundaries of 3D arrangement subdivided by a given set of triangles. An outer cell boundary is defined as a 2-manifold surface consisting of subdivided polygons facing outward. Many geometric problems, such as Minkowski sum, sweep volume, lower/upper envelop, Bool operations, can be reduced to finding outer cell boundaries with specific properties. Computing outer cell boundaries, however, is a very time-consuming job and also is susceptible to numerical errors. To address these problems, we develop an algorithm based on GPU with a robust scheme combining interval arithmetic and multi-level precisions. The proposed algorithm is tested on Minkowski sum of several polygonal models, and shows 5-20 times speedup over an existing algorithm running on CPU.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.1
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• pp.85-89
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• 2007

Many authors considered the computational aspect of sup-min convolution when applied to weighted average operations. They used a computational algorithm based on a-cut representation of fuzzy sets, nonlinear programming implementation of the extension principle, and interval analysis. It is well known that $T_W$(the weakest t-norm)-based addition and multiplication preserve the shape of L-R type fuzzy numbers. In this paper, we consider the computational aspect of the extension principle by the use of $T_W$ when the principle is applied to fuzzy weighted average operations. We give the exact solution for the case where variables and coefficients are L-L fuzzy numbers without programming or the aid of computer resources.

• Journal of KIISE:Software and Applications
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• v.27 no.11
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• pp.1073-1081
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• 2000

본 연구에서는 효과적인 시계열 예측을 위하여 구간연산 기능을 갖는 신경망모델을 제안한다. 이는 기존의 FIR 네트워크의 동작특성을 구간연산으로 일반화함으로써 시계열 신호의 동적 특성을 효과적으로 반영할 뿐만 아니라 학습데이타 표현의 유연성을 증대시킨다. 이는 또한 실제 응용에서 신경망 입력 데이타에 내재할 수 있는 측정치 오류의 영향을 보완할 수 있게 하며 데이타 그룹화를 효과적으로 이룰 수 있게 함으로써 입력데이타의 양을 감축시키고 이로부터 학습의 효율을 개선한다. 본 논문에서는 구간연산을 이용하여 네트워크 동작특성, 학습알고리즘을 제시하고 실제 응용시스템에 이를 적용함으로써 제안된 이론의 유용성을 평가한다.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.6 s.113
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• pp.1-11
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• 2006

The purpose of this study was to investigate the influence of natural landscapes in the context of work environments. The study examined the impact of natural landscapes on urban office workers' stress reduction and cognitive performance, using physiological, psychological, and cognitive measures. One-hundred-twenty urban office workers participated in the experiments. The physiological measures used were GSR (galvanic skin response) and IBI (interbeat interval), and the psychological measure was ZIPERS (Zucherman Inventory of Personal Reactions). Cognitive performance was measured using a mental arithmetic test that had been developed by a pretest. The results from the physiological, psychological, and cognitive measures converged to indicate that the natural landscape had more beneficial effects in relieving both psychological and physiological stress and in enhancing cognitive performance of the of office workers than the city landscape. The results suggest wide applications in the fields of workers' well-being and landscape research. First, the results can provide reliable information for promoting natural landscaping in work places in order to relieve worker stress and enhance cognitive performance. Second, the results provide an example for future empirical landscape research using multiple measurements, such as psychological, physiological, and cognitive tests. Third, they can foster experimental research to investigate the relationship between stress reduction and natural landscapes.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.693-703
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• 2012

Load Duration Curve(LDC) is a useful tool for analyzing water quality characteristics under various stream flow conditions. This study investigated the methods to identify impaired waterbodies in the assessment of water quality goal attainment by using LDC for the management of Total Maximum Daily Loads (TMDLs). Three methods were proposed. Non-typical regime exclusion method is a method to exclude water quality observations in the non-typical extreme flow conditions in order to minimize the influence of non-ordinary water quality. Flow regime weighted average method is a method to calculate weighted mean water quality instead of arithmetic mean in order to consider water characteristics properly on stream flow regime in addition to the effect of Non-typical regime exclusion method. Load exceeded interval comparison method is a method to compare the intervals between the attained and non-attained load duration periods on the LDC. The assessment of water quality goal attainment can be performed more reasonably and precisely considering water quality variations on stream flow conditions by applying these proposed methods.