• 한국의류학회지
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• 제36권12호
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• pp.1285-1296
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• 2012

This study investigates the effects of changes in price, total consumption expenditures and economic sitations on Korean household demands for clothing and footwear using time-series data. The clothing and footwear category was reclassified as clothing, footwear and clothing services items for the demand analysis. This study utilized the Linearized Almost Ideal Demand System (LAIDS) model to analyze household demand. The results indicate that price and total consumption expenditures are significantly related to Korean household consumption expenditure allocations for clothing and footwear items. The effects of the IMF bailout crisis in 1997 and the global financial crisis in 2008 on household expenditure shares for clothing and footwear items were very weak and statistically insignificant. All the demand elasticities were estimated with respect to total consumption expenditures and prices. Clothing was expenditure elastic (greater than one) and other items were classified as inelastic. All the own price elasticities of demands were negative (other than clothing). Through the estimations of cross price elasticity the relationships between the demands for items and other item prices were evaluated (i.e., substitutes and complements).

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2013년도 자성 및 자성재료 국제학술대회
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• pp.32-32
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• 2013

Using the Vienna ab initio simulation package (VASP) incorporating van der Waals interaction, we have explored structural, adsorption, and magnetic properties of Ni(111)/BN/Co(111) systems. We have found that both Ni(111) and Co(111) layers shows half metallic state, while the spacer BN layer becomes weak metal for one monolayer (ML) thickness and an insulating barrier for two ML thickness. The half metallic states in both Ni(111) and Co(111) layers are robust because it is unchanged independently on the magnetic coupling of Ni(111) and Co(111). This finding suggests that the Ni(111)/BN/Co(111) systems can be utilized for perfect tunneling magnetoresistance system. Moreover, it can be applied for potential spin injecting into semiconductor in FM/semiconductor system due to the fact that the half metallic state in FM layers at the interface will be unchanged.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권4호
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• pp.291-296
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• 2005

In this paper, we introduce a generalized synchronization method and secure communication in the State-Controlled Cellular Neural Network (SC-CNN). We make a SC-CNN using the n-double scroll. A SC-CNN is created by applying identical n-double scroll or non-identical n-double scroll and Chua's oscillator with weak coupled method to each cell. SC-CNN synchronization was achieved using GS(Generalized Synchronization) method between the transmitter and receiver about each state variable in the SC-CNN. In order to secure communication, we have synthesizing the desired information with a SC-CNN circuit by adding the information signal to the hyper-chaos signal using the SC-CNN in the transmitter. And then, transmitting the synthesized signal to the ideal channel, we confirm secure communication by separating the information signal and the SC-CNN signal in the receiver.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.289-293
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• 2005

this paper, we introduce a secure communication method using complex system. We make a complex system with the n-double scroll or Chua's oscillator. The Complex system is created by applying identical n0double scroll or non-identical n-double scroll and Chua's oscillator with weak soupled method to each cell. In order to secure communication, we have synthesizing the desired information with a complex system circuit by adding the information signal to the hyper-chaos signal. And then, transmitting the synthesized signal to the ideal channel, we confirm secure communication by separating the information signal and the complex system signal in the receiver.

• 대한수학회지
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• 제58권6호
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• pp.1311-1325
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• 2021

One says that a ring homomorphism R → S is Ohm-Rush if extension commutes with arbitrary intersection of ideals, or equivalently if for any element f ∈ S, there is a unique smallest ideal of R whose extension to S contains f, called the content of f. For Noetherian local rings, we analyze whether the completion map is Ohm-Rush. We show that the answer is typically 'yes' in dimension one, but 'no' in higher dimension, and in any case it coincides with the content map having good algebraic properties. We then analyze the question of when the Ohm-Rush property globalizes in faithfully flat modules and algebras over a 1-dimensional Noetherian domain, culminating both in a positive result and a counterexample. Finally, we introduce a notion that we show is strictly between the Ohm-Rush property and the weak content algebra property.

• Korean Journal of Mathematics
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• 제27권2호
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• pp.375-415
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• 2019

We study spaces of continuous-function-valued functions that have the property that composition with evaluation functionals induce $weak^*$ to norm continuous maps to ${\ell}^p$ space ($p{\in}(1,\;{\infty})$). Versions of $H{\ddot{o}}lder^{\prime}s$ inequality and Riesz representation theorem are proved to hold on these spaces. We prove a version of Dixmier's theorem for spaces of function-valued matrix operators on these spaces, and an analogue of the trace formula for operators on Hilbert spaces. When the function space is taken to be the complex field, the spaces are just the ${\ell}^p$ spaces and the well-known classical theorems follow from our results.

• 대한수학회논문집
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• 제36권2호
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• pp.209-227
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• 2021

In this paper, we deal with the question that what kind of properties does a ring gain when it satisfies symmetricity or reversibility by the way of nilpotent elements? By the motivation of this question, we approach to symmetric and reversible property of rings via nilpotents. For symmetricity, we call a ring R middle right-(resp. left-)nil symmetric (mr-nil (resp. ml-nil) symmetric, for short) if abc = 0 implies acb = 0 (resp. bac = 0) for a, c ∈ R and b ∈ nil(R) where nil(R) is the set of all nilpotent elements of R. It is proved that mr-nil symmetric rings are abelian and so directly finite. We show that the class of mr-nil symmetric rings strictly lies between the classes of symmetric rings and weak right nil-symmetric rings. For reversibility, we introduce left (resp. right) N-reversible ideal I of a ring R if for any a ∈ nil(R), b ∈ R, being ab ∈ I implies ba ∈ I (resp. b ∈ nil(R), a ∈ R, being ab ∈ I implies ba ∈ I). A ring R is called left (resp. right) N-reversible if the zero ideal is left (resp. right) N-reversible. Left N-reversibility is a generalization of mr-nil symmetricity. We exactly determine the place of the class of left N-reversible rings which is placed between the classes of reversible rings and CNZ rings. We also obtain that every left N-reversible ring is nil-Armendariz. It is observed that the polynomial ring over a left N-reversible Armendariz ring is also left N-reversible.

• 건축역사연구
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• 제2권1호
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• pp.9-24
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• 1993

The objective of this study is to describe more positively and concretely the entity of traditional village through the quantitative and scientific analysis process using positive data. Dan-Gye, a traditional village in San-Cheong, has been populated since more than 500 years ago because of its ideal conditions for settlement. In this study, the fluctuations on the numbers of households in Dan-Gye were analyzed from the first settlement era to the present, and the transformations of housing sites and roads since 1913 were also analyzed. The results are as follows. 1) The village Dan-Gye has a history of more than 500 years, and the first inhabitants were the Ryus. As time went by, the Ryus' power became weak gradually, but the powers of the Kwons and the Parks who had flowed later into this village became prosperous to make up a prominent family village in the late period of Cho-Sun dynasty. Such powers had reached the peak in the early period of Japanese occupation, and although the powers became weak gradually after that time, those two families have overwhelmed other families in population and possession of large houses until now. But as the confucianism in every-day life fell off and the inhabitants moved to cities, the existence of a family community became meaningless. 2) The Kwons and the Parks have possessed the large parts of the village's housing sites. As time went by, the sites have been divided and fields have been changed to housing sites for the increasing families, and such division and change have been made chiefly on perimeter areas. 3) The characteristics of the road in Dan-Gye where traditional roads existed began to be destroyed by Japanese construction of new roads, and such destruction has continued due to the bank construction after a flood and the road constructions after 1970s.

• 한국수학사학회지
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• 제31권5호
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• pp.251-269
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• 2018

Empirical probability and classical probability, which are two interpretations of Kolmogorov's axiom, are two ways to recognize the chances of events occurring in the real world. In this paper, I analyzed and suggested the contents of the high school textbooks ${\ll}$Probability and Statistics${\gg}$, associated with two interpretations of probability and experiments on which two interpretations are based. By presenting the cases required expressly stating what the experiment is for supporting students' understanding of some concepts, it was discussed that stating or not stating what the experiment is should be carefully determined by the educational intent. Especially, I suggested that in the textbooks we contrast the good idea of calculating the ratios of two possibilities in the imaginary world of the classical probability with the normal idea of grasping the chances of events through the frequencies in the real world of the empirical probability, with distinguishing the experiments in two interpretations of probability. I also suggested that in the textbooks we make it clear that the Weak Law of Large Numbers justifies our expectations of the frequencies' reflecting the chances of events occurring in the real world under ideal conditions. Teaching and learning about the aesthetic elements and the practicality of imaginary mathematical thinking supported by these textbooks statements could be one form of Humanities education in mathematics as STEAM education.

• 유통과학연구
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• 제15권8호
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• pp.29-36
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• 2017

Purpose - This paper proposes some ideas with a view to reducing any possible accidents caused by unlicensed drivers and an illegal use of other's name, particularly by teenagers in consideration of easy and simple instruction on smartphone with very weak and mere consciousness on auto life. Research design, data, and methodology - This study analyzes some accident cases between cargo trucks and rental cars in South Korea, and unlicensed vehicle with unlicensed drivers who use rental cars collided with cargo trucks which were loaded a lot of goods to be delivered to buyer designated. In order to fulfill this research, a case study accompanied with literature survey was conducted. Ideal suggestion for the right growth on rental car industry will be realized by legislation of the law. Results - This paper classified bodily injury of the victim, property damage and damaged cargo arising out of the unlicensed who is driving on car sharing service in South Korea. Conclusions - For the purpose of reducing cargo accidents caused by unlicensed drivers and an illegal use of other's name particularly by teenagers, this paper proposes some ideas of Amendment of the law, Paradigm shift of car sharing company, Preparation by association side and Technical Complementary Measures in South Korea.