• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.193-199
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• 2004

Numerical analysis of aerodynamic characteristics was differently performed according to the running situation of the Korean Tilting Train eXpress(TTX) that would be introduced for an improvement in efficiency of the used railroad track. Fluent 6.0 was used for the analysis of Non-tilting case, Tilting case and Passing-by case with the model of TTX. As a result, the aerodynamic drag had little difference between Tilting and Non-tilting case. However, pressure contour under the train of Tilting case was not symmetry because the gap between a train and the ground was different at both sides. In Passing-by case attraction and counterattraction occurred alternately and affected to the opposite train. When two trains were side by side, the maximum attraction was generated especially. Through an analysis of pressure wave in tunnel a large variation of pressure was generated by the bluff nose of TTX. The results in this study would be good data for the aerodynamic characteristic on TTX and provide important information to judgment of running safety.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.103-112
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• 2021

The labor force plays an important role in attracting foreign direct investment (FDI) both in developed and developing countries. In countries where there are appropriate policies for training human resources and maintaining the health of human resources, such countries have a competitive advantage and can attract FDI inflows, besides having a workforce to meet the needs of foreign investors. The purpose of this paper is to analyze the effect of the labor force and several other factors on FDI attraction in Vietnam. The empirical model is employed to perform regression and correlation on the impact of the labor force, real gross domestic product, inflation, index of business freedom, and index of investment freedom on Vietnam's FDI attraction by using a secondary time series data set during the period 1995-2018. The empirical results found that both labor force and inflation have a positive influence on FDI at a 5% significance level; index of business freedom has a positive impact on FDI at a 10% significance level, and real gross domestic product and index of investment freedom have a positive impact on FDI at a 1% significance level. From these results, this study proposes several important policy implications for Vietnam in attracting FDI in the future.

• Journal of Distribution Science
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• v.21 no.2
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• pp.1-6
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• 2023

Purpose: Research on attracting foreign direct investment plays an important role in ASEAN countries. ASEAN has needed FDI capital for development and integration with many developing countries. Research design, data and methodology: This study is conducted to assess the impact of factors: inflation (INF), economic growth (GDP), population (POP), and trade (TRADE) on attracting foreign direct investment (FDI) of ASEAN countries. The study will find out how factors distribution contributes to FDI attraction. The study collects data from 10 ASEAN countries from 2010 to 2020. With data collected for ten countries from 2010 to 2020, data analysis with panel data will be used in this study. The Regression with Driscoll-Kraay standard errors correction model will be used in the study. Results: Panel data analysis shows that economic growth and population positively impact FDI attraction in ASEAN countries. However, two factors: INF and TRADE, do not affect FDI. Conclusions: Countries need to focus on economic development, create many good conditions for people and domestic enterprises and create opportunities for foreign investors to pay more attention. improving the quality of domestic human resources will help to better improve the working quality factor when the demand for high-quality human resources increases.

• Bulletin of the Korean Mathematical Society
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• v.43 no.3
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• pp.575-587
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• 2006

In this paper, we provide 3 detailed and explicit procedure of obtaining some regions of attraction for the positive steady state (assumed to exist) of a well known Lotka-Volterra type predator-prey system. Also we obtain the sufficient conditions to ensure that the positive equilibrium point of a well known Lotka-Volterra type predator-prey system with a single discrete delay is globally asymptotically stable.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.317-323
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• 2005

To increase the operating speed of the solenoid actuator, this paper proposed a modified model using a non-magnetic ring, which is welded on the magnetic guide tube, and also presents the characteristic equations, results of Finite Element Method (FEM) analysis for magnetic flux distribution and density in magnetic flux paths, and computer simulation results for the dynamic characteristics of plunger motion according to the stroke and time variation. As well, we proved the non-magnetic ring effect by experiments using prototypes.

• Annual Conference of KIPS
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• 2023.11a
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• pp.745-747
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• 2023

여러 분야에서 인공지능 모델을 활용한 추천 방법들이 많이 사용되고 있다. 본 논문에서는 관광지의 대중적이고 정확한 추천을 위해 GPT-3 와 같은 생성 모델로 생성한 가상의 리뷰 문장을 통해 KoBERT 모델을 학습했다. 생성한 데이터를 통한 KoBERT 의 학습 정확도는 0.98, 테스트 정확도는 0.81 이고 실제 관광지별 리뷰 데이터를 활용해 관광지를 분류했다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.1
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• pp.29-42
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• 2019

In order to expand the qualitative aspects of public facility, this study used SNS data to derive user-oriented preference factors for public facilities and then were quantified in terms of supply side and demand side. To derive preference factor, LDA, one of topic modeling, was used and attraction index was calculated for each facility. In addition we analyzed spatial accessibility to measure the degree of service experience of users by using 2SFCA model. The study area covered public libraries of Seoul, Korea. As a result of study, five topics were extracted as preference factors for the public library: Circumstance, Scale of facility, Cultural program, Parenting, Books and materials. In particular topic of circumstance and parenting were newly derived preference factors unknown in previous studies. As a result of calculating attraction index for each library, the index of Songpa Library, Jungdok Library, and Namsan Library was high. Songpa library has received good evaluation in parenting factor, and Jungdok & Namsan library in circumstance factor. The accessibility of each region seems to better in center of Seoul where public libraries are crowded, but shrinking toward the outskirts. We expect that the proposed method will contribute to user-oriented public facility evaluation and policy decision making.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.101-102
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• 2011

The attraction force is an important parameter for permanent-magnet(PM) linear machines. This paper aims to analysis lumped magnetic circuit model of a magnetic levitation system. It accounts for the fringing effect and leakage flux which may greatly affect the accuracy of the analytical model for the optimal lumped magnetic circuit model. consequentially it will be able to apply to prospective permanent-magnet(PM) linear machines for accurate analysis.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1460-1465
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• 2007

In this paper, the conventional linear induction motor(LIM) used in propelling the MAGLEV in Korea is redesigned in order to reduce its weight. The specifications of the newly designed model for base speed, acceleration, rated thrust and maximum output is respectively 45km/h, 4.0km/h/sec, 5,200[N] and 65 [kW]. Weight reduction effect of the LIM according to the change of pole number from 8 to 6 is shown. Equivalent circuit analysis considering end effect and finite element method are used for the analysis of the redesigned model. Finally the weight reduction ratio of the newly designed LIM to the conventional model, thrust, attraction force, line current, temperature rise, flux density distribution are presented.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1041-1046
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• 2004

A proportional pressure control valve has a nonmagnetic ring which is inserted in between a coil and plunger and it can get attraction force in proportion to input current by an influence of control cone. Therefore, a proportional pressure control valve is applied to a servo system as substitution of servo valve and an on-off solenoid valve widely because control of a high level is possible and pollution level is low. The purpose of this study is to develop domestic model of a proportional pressure control valve, and a test model was designed and manufactured through valve system analysis and finite element analysis. And comparison between results of theoretical analysis and static / dynamic characteristics test were carried out on a manufactured test model, and it was confirmed that it has excellent performance in comparison with other foreign products.