• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.561-569
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• 2019

Solar photovoltaic can provide electrical energy with only radiation, and its use is expanding rapidly as a new energy source. This study predicts the short and long-term PV power generation using actual converter output data of photovoltaic system. The prediction algorithm uses multiple linear regression, support vector machine (SVM), and deep learning such as deep neural network (DNN) and long short-term memory (LSTM). In addition, three models are used according to the input and output structure of the weather element. Long-term forecasts are made monthly, seasonally and annually, and short-term forecasts are made for 7 days. As a result, the deep learning network is better in prediction accuracy than multiple linear regression and SVM. In addition, LSTM, which is a better model for time series prediction than DNN, is somewhat superior in terms of prediction accuracy. The experiment results according to the input and output structure appear Model 2 has less error than Model 1, and Model 3 has less error than Model 2.

• International Journal of Highway Engineering
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• v.18 no.1
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• pp.63-72
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• 2016

PURPOSES : The use of roller-compacted concrete pavement (RCCP) is an environmentally friendly method of construction that utilizes the aggregate interlock effect by means of a hydration reaction and roller compacting, demonstrating a superb structural performance with a relatively small unit water content and unit cement content. However, even if an excellent structural performance was secured through a previous study, the verification research on the environmental load and long-term durability was conducted under unsatisfactory conditions. In order to secure longterm durability, the construction of an appropriate internal air-void structure is required. In this study, a method of improving the long-term durability of RCCP will be suggested by analyzing the internal air-void structure and relevant durability of roller-compacted concrete. METHODS : The method of improving the long-term durability involves measurements of the air content, air voids, and air-spacing factor in RCCP that experiences a change in terms of the kind of air-entraining agent and chemical admixture proportions. This test should be conducted on the basis of test criteria such as ASTM C 457, 672, and KS F 2456. RESULTS : Freezing, thawing, and scaling resistance tests of roller compacted concrete without a chemical admixture showed that it was weak. However, as a result of conducting air entraining (AE) with an AE agent, a large amount of air was distributed with a range of 2~3%, and an air void spacing factor ranging from 200 to $300{\mu}m$ (close to $250{\mu}m$) coming from PCA was secured. Accordingly, the freezing and thawing resistance was improved, with a relative dynamic elastic modulus of more than 80%, and the scaling resistance was improved under the appropriate AE agent content rate. CONCLUSIONS : The long-term durability of RCCP has a direct relationship with the air-void spacing factor, and it can be secured only by ensuring the air void spacing factor through air entraining with the inclusion of an AE agent.

• Journal of Magnetics
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• v.12 no.3
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• pp.97-102
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• 2007

We have investigated the electronic structures and magnetism of a full Heusler alloy $Co_2CrGa(001)$ surface by using the all-electron full-potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation (GGA). We considered two types of different terminations: the Co-terminated (Co-Term) and the CrGa-terminated (CrGa-Term) surfaces. From the calculated layer-projected density of states (LDOS), we found that the surface of the CrGa-Term shows nearly half-metallic character while that of the Co-Term is far from the half-metallic. For the Co-Term, the surface Co atom moves down to the bulk region by $0.05{\AA}A$, while the subsurface Cr and Ga atoms move up to the surface layer by 0.05 and $0.01{\AA}$, respectively. For the CrGa-Term, there is a large inward relaxation of the surface Ga atom $(0.07{\AA})$, but the relaxation of the surface Cr atom is very small $(0.01{\AA})$. The relaxations affect not much to the overall shapes of DOS for both terminations, but make the surface states of the surface Cr and Ga atoms for the CrGa-Term shift to higher energy that enhances the nearly half-metallic character of the CrGa-Term. The magnetic moments of the surface $Cr(2.98{\mu}_B)$ in the CrGa-Term and the surface $Co(1.17{\mu}_B)$ in the Co-Term were much increased compared to those of the inner-layers $(1.79\;and\;0.77{\mu}_B)$, respectively, while that of the subsurface Cr atom in the Co-Term was decreased to $1.19{\mu}_B$.

• Journal of the Korean Statistical Society
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• v.4 no.2
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• pp.113-125
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• 1975

The money market has been existing in various forms for a long time. Until 1972, however, the market had supplied mainly short-term loans of commercial banks and loans of informal money lenders to business corporations. There was no market for notes and commercial papers of business corporations. Consequently, business corporations had to rely primarily upon commercial banks for short-term credit loans to supplement their working capital. The interest rate on loans of commercial banks had been set below a free market equilibrium rate and thereby, generated excess demands for the loans. Unsatisfied potential borrowers thus had to turn to informal money lenders for short-term cerdit loans of prohibitively high interest rate. Since 1972 investment and finance companies have been operating in the money market and their role in mobilizing short-term loans is increasing. This paper aims at estimating the equilibrium size of the money market.

• East Asian Economic Review
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• v.18 no.2
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• pp.187-212
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• 2014

The purpose of this paper is to examine the equity market crisis contagion in major Asian economic markets. A comparative assessment of Asian markets during the Asian Financial Crisis and Global Financial crisis may clearly identify the changing nature of long term integration of major Asian markets. The selection criteria of specific Asian markets of different peripheries depend particularly on the roles and structure of these markets. The impact of the global financial contagion and the lingering financial linkage in the aftermath of crisis will explain the reaction of the majority of Asian markets to global linkage. While majority of the studies focused on dynamic short term association in European and MENA contagions in the post global financial crisis period; after the global financial crisis, attention paid to long term Asian contagion adds new perspective to hitherto disorganized theories.

• Journal of Korean Association for Spatial Structures
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• v.10 no.1
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• pp.111-117
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• 2010

This thesis draws institutional problem about safety of architectural structure through analysis of architectural structure regulation. The law of analysis target are building codes, enforcement ordinance of building codes, enforcement regulations of building codes, regulation for structure standards of building, building structure standards. The analysis showed there are imperfections in confirmed procedural application of structure safety and suggested reformation. It's necessary to make supplementary policies for the suitability of the term use and the structure safety certificate of compliance, establishing a special structure code.

• East Asian mathematical journal
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• v.39 no.2
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• pp.167-181
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• 2023

The purpose of this study is to confirm the possibility of whether learning using a math learning platform can be used to expand students' conceptual structure and to consider how to use it. To this end, first-year middle school students studied using a math learning platform. Then, the concept map created was compared and analyzed with the concept map created before learning to examine the change in the concept structure. The results of analyzing the concept map are as follows. First, the change in the hierarchical structure of the concept appeared as the division of the upper concept was subdivided. However, it has also been changed to comprehensively integrate and simplify higher concepts. The term-centered concept structure has changed to content-centered superordinate and subordinate concepts. In the concept structure, subordinate concepts linked to one higher concept were expanded and differentiated. Second, changes in the integrated structure did not form a linkage structure. The expansion of the integrated structure of concepts through learning using the learning platform was influenced by the composition of the learning contents designed in the learning platform.

• Journal of Distribution Science
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• v.15 no.2
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• pp.37-46
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• 2017

Purpose - This research investigates whether e-service quality has the influence on long-term orientation, consumer commitment, and satisfaction. Research design, data, and methodology - Data collection took place for 30 days from October 1, 2015 to October 31, 2015. 315 copies had been analyzed. Covariance structure analysis with credibility and factor analysis was conducted to verify this research hypotheses. Results - First, the lower dimension concepts of e-service quality, reliability, and tangibility had a significant influence on customer commitment, and responsiveness had a significant negative influence. However, aesthetics did not have a significant influence on that. Secondly, aesthetics had a significant influence on long-term orientation, but reliability, tangibility, and responsiveness did not have a significant influence. Thirdly, reliability, tangibility, and aesthetics had a positive influence on customer satisfaction. However, responsiveness had a negative influence. Fourthly, customer commitment had a significant and positive influence on customer satisfaction, but customer commitment and customer satisfaction had a negative influence on long-term orientation. Conclusions - This research verifies the influencing relationship between e-service quality of a franchise coffee shop application with customer commitment, customer satisfaction, and long term orientation. By the results of this research, possibility of application and expansion of theory has been proven.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.891-895
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• 2001

An alternative inverse feedback structure for adaptive active control of periodic noise is introduced for systems with nonminimum phase cancellation path. To obtain the inverse model of the nonminimum phase cancellation path, the cancellation path model can be factorized into a minimum phase term and a maximum phase term. The maximum phase term containing unstable zeros makes the inverse model unstable. To avoid the instability, we alter the inverse model of the maximum phase system into an anti-causal FIR one. An LMS predictor estimates the future samples of the noise, which are necessary for causality of both anti-causal FIR approximation for the stable inverse of the maximum phase system and time-delay existing in the cancellation path. The proposed method has a faster convergence behavior and a better transient response than the conventional filtered-x LMS algorithms with the same internal model control structure since a filtered reference signal is not required. We compare the proposed methods with the conventional methods through simulation studies.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.225-231
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• 2003

The injection molding is a traditional manufacturing method that can make plastic parts by just one time in mold. Therefore, the injection molding has become one of a manufacturing method, which is widely applied in a producing of plastic products. Nowadays, to use of plastic parts has increased and plastic product-model using term has been shorten. By these reasons, using term of a injection mold has fast been reduced. These produced molds will be disused and leaved in a storage after a regular term to use it. These leaved molds are sometime sold as scrap iron. But, these molds have lots parts for recycling except special parts for example, cavities, cores and eject pins, etc. In this research, we investigated when the cavity and core of in injection mold would be changed, the injection mold could be recycled. We suggested the structures and standardizations for recycling of a moldbase. We also developed a program in which can be used when the recycling moldbase design in the Auto-CAD with the recycling standards. We called this program as the Recy-Mold. For the availability of the program and moldbase structure fur the recycling standards, we experimented a used mold for automobile lens, which was remanufactured by the recycling standard. The results of this test showed feasibility for the recycling mold.