• Nonlinear Functional Analysis and Applications
• /
• v.26 no.3
• /
• pp.513-530
• /
• 2021

The purpose of this paper is to introduce and study a class of coupled systems of fuzzy delay differential equations involving fuzzy initial values and fuzzy source functions of triangular type. We assume that these initial values and source functions are triangular fuzzy functions and define solutions of the coupled systems as a triangular fuzzy function matrix consisting of real functional matrices. The method of triangular fuzzy function, fractional steps and fuzzy terms separation are used to solve the problems. Furthermore, we prove existence and uniqueness of solution for the considered systems, and then a solution algorithm is proposed. Finally, we present an example to illustrate our main results and give some work that can be done later.

• Nonlinear Functional Analysis and Applications
• /
• v.29 no.3
• /
• pp.739-751
• /
• 2024

In this paper, we study the existence and uniqueness of solutions for a class of fractional differential inclusion including a maximal monotone operator in real space with an initial condition. The main results of the existence and uniqueness are obtained by using resolvent operator techniques and multivalued fixed point theory.

• International Area Studies Review
• /
• v.13 no.1
• /
• pp.3-16
• /
• 2009

This paper investigates the existence of uncovered interest rate parity between the Korea-USA as well as the Korea-Japan. We may ascertain the existence of uncovered interest rate parity by examining the empirical relationship between real exchange rates and interest rate differentials in the Korea-USA as well as in the Korea-Japan. The empirical relationship between real exchange rates and interest rate differentials in the Korean-USA and Korean-Japanese economies is investigated using cointegration tests. In the context of this study, cointegration technique is appropriate to examine the relationship between two(or more) nonstationary time series. Also, this method is useful to detect the possibility that the nonstationarity in both series can be explained by a single factor. The empirical results support the nonexistence of a long run equilibrium relation between real exchange rates and interest rate differentials. Also, the results show that the nonstationarity cannot be explained by a single factor.

• Journal of the Korean Geographical Society
• /
• v.32 no.4
• /
• pp.543-548
• /
• 1997

New technologie of information and interaction create ambiguous, multifaceted relationships between concepts and realities that once seemed clear and simple. The acvent of cyberspace implies the existence of cyberplaces and relationships among cyberspace and places that could be as or more complex then those that exist among the spaces and places of the non-digital world. Virtual reality-the current uses of infomation technologies to create replicas of places and processes in the world-offers a point of exploring such relationships. But more penetrating insights become evident in the examination of real virtuality-the uses of information technologies to enhance the experience of places in the world. Real virtuality offers geographers a variety of innovative and powerful tools for augmenting the effectiveness and domain of their craft. Widespread use of real virtuality by geograpgers will alter their use of data, methods, and theory in research, teaching, and practice.

• Korean Institute of Interior Design Journal
• /
• v.16 no.5
• /
• pp.126-133
• /
• 2007

This study is intended to set the concept of becoming meaning of digital space through digital technology and to study the influence of digital space on becoming of real space through derived keyword. The results of this study are summarized as follows. First, the digital concept is created in the process that the virtual space is changed into the real space with a priority given to form, space and time. Digital expression concept and image concept the structural becoming, and idea concept and creative concept creates the time becoming. Second, the concept of digital becoming exposes a physical visibility through the digital's virtual image, and non-space spatiality through the space simulation. It also continuously reveals a consecutive time and non-consecutive time through a statable progress, incremental progress, and dynamic progress. Third, as the influence of digital on becoming of real space, the digital visibly not only expresses the new and difficult becoming problem through conceptual virtuality, but also can review the real space's space concept with virtuality in the digital non-area. Digital's durability expresses the new space's existence by physically combining with the existing space through the virtual form creation.

• International conference on construction engineering and project management
• /
• 2017.10a
• /
• pp.62-72
• /
• 2017

In this study, liner unit root tests and panel unit root tests to the ratio of city to regional house price were applied to examine the ripple effects across 28 cities in the Yangtze River Delta region. Then invert LM unit root tests with two structural breaks for 10 representative cities were conducted. The results showed that there is overwhelming evidence of the existence of ripple effect in the Yangtze River Delta region, while segmentation is restricted to a small group of cities in which there is no long-run relationship with the Yangtze River Delta region average; compared to no- and one-break case, there is overwhelming evidence of a ripple effect with the LM test with two structural breaks. Furthermore, the results of the Granger causality test showed that changes in house prices in Shanghai, Nanjing and Hangzhou have led to changes in house prices in other cities. The findings of this research make certain contributions to the improvements of research system of ripple effect among regional house prices in the Yangtze River Delta Region,and could be referenced by other markets of other cities.

• Journal for History of Mathematics
• /
• v.33 no.6
• /
• pp.327-343
• /
• 2020

This study investigate philosophical discussions related to the Zeno's paradoxes in order to derive the mathematics educational implications. The paradox of Zeno's motion is sometimes explained by the calculus theories. However, various philosophical discussions show that the resolution of Zeno's paradox by calculus is not a real solution, and the concept of a continuum which is composed of points and the real number continuum may not coincide with the physical space and time. This is supported by the fact that the hyperreal number system of nonstandard analysis could be another model of a straight line or time and that an alternative explanation of Zeno's paradox was possible by the hyperreal number system. The existence of two different theories of the continuum suggests that teachers and students may not have the same view of the continuum. It is also suggested that the real world model used in school mathematics may not necessarily match the student's intuition or mathematical practice, and that the real world application of mathematics theory should be emphasized in education as a kind of 'correspondence.'

• Journal of applied mathematics & informatics
• /
• v.17 no.1_2_3
• /
• pp.329-341
• /
• 2005

In this paper, we introduce new random iterative sequences with errors approximating a unique random common fixed point for three random set-valued strongly pseudo-contractive mappings and show the convergence of the random iterative sequences with errors by using an approximation method in real uniformly smooth separable Banach spaces. As applications, we study the existence of random solutions for some kind of random nonlinear operator equations group in separable Hilbert spaces.

• Honam Mathematical Journal
• /
• v.32 no.4
• /
• pp.633-642
• /
• 2010

In this note, we introduce the definition of the generalized analogue of Wiener measure on the space C[a, b] of all real-valued continuous functions on the closed interval [a, b], give several examples of it and investigate some important properties of it - the Fernique theorem and the existence theorem of scale-invariant measurable subsets on C[a, b].

• The Pure and Applied Mathematics
• /
• v.9 no.1
• /
• pp.47-55
• /
• 2002

In this pope., we consider a Minty's lemma for ($\theta ,\eta$)-pseudomonotone-type set-valued mappings in real Banach spaces and then we show the existence of solutions to variational-type inequality problems for ($\theta ,\eta$)-pseudomonotone-type set-valued mappings in nonreflexive Banach spaces.