• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.24-26
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• 2002

The recent emphasis on energy conservation demands an improvement of the efficiency of single-phase induction motors. To take the efficiency operation of the capacitor run single-phase induction motor with auxiliary and main winding, it is very important to select the capacitance value. This paper describes the theoretical analysis method of a single-phase induction motor which is based on the rotating field theory, using the method of symmetrical components. The optimal selection method of capacitance is proposed.

• Proceedings of the Technology Innovation Conference
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• 2004.02a
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• pp.83-107
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• 2004

This study investigates how and through which channels R&D activities influences the national economy, using a macro-econometric model. The macro-econometric model in this study includes 24 behavioral equations and 25 identities and was estimated using the annual data. From a simulation analysis, it is shown that the R&D investment has a permanent effect on real variables; lowering prices, wages and interest rates, and increasing potential and real GDP in the long run. It is noted that the national account was recalculated to avoid double-counting in estimation of R&D stocks.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.342-344
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• 1999

This paper presents the analysis of core losses in capacitor-run single phase induction motors using the finite element methods. The double revolving field theory can be used for the analysis to assess the quantitative and qualitative performance of the single-phase induction motor. But it is difficult to evaluate accurately the core losses. It is more difficult to segregate stator and rotor core losses at no-load and load conditions. Numerical analysis such as FEM can be used effectively for the accurate calculation of core losses and motors performances. In this paper, the coupling method of core loss characteristic equation and FEM are proposed for the accurate calculation of core losses in the stator and rotor. The FFT is also used to calculate fundamental and harmonic components in the yoke and teeth parts of motor.

• The Journal of Fisheries Business Administration
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• v.40 no.2
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• pp.105-126
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• 2009

This study applies the cointegration theory to analyse the causality of the prices between imported fisheries and domestic fisheries in distribution channel. We've focused on the prices of import, wholesale and retail about the frozen Alaska pollack, hairtail and croaker which take up high portion and are popular among most of the consumers. In process of analysis, the unit root test was adopted to find the stability of time series data prior to the cointegration test. If the time series data was found as stable one in unit root test, we should analyse the VAR model. If unstable, the cointegratioin test was adopeted to find the long-run equilibrium relationship between the data. When the long-run equilibrium relationship was found among the price of the import, wholesale and retail price, the VECM model was adoped. If not, the differenced VAR model was adopted. The main findings of this study could be summarized as follows ; First, according to the result of the analysis on VAR model, time series data of frozen Alaska pollack was found as stable and has causality relationship and close effect was existing among the import, wholesale and retail price. Second, the data of frozen hairtail was found as an unstable one in unit root test and the result of cointegration test showed the long-run equilibrium relationship at lag 1. From the results of VECM model, we could find that the coefficient of error correction is effective, and the sign is negative(-). It means that the existence of adjustment tendency to long-run equilibrium after a short-run deviation. But the short-run causality of the prices were not found except the price of wholesale. Third, according to the results of differenced VAR model, data from frozen croaker did not have the stability and long-run equilibrium. Moreover, it was found that the import price has a weak causality on the retail price. Because of having difficulties in collecting data, the result of this paper could not explain the relationship among the prices of import, wholesale and retail perfectly. However, it more or less contributed to a long-lasted debate on the direction of causality of price-setting in academic research and provided a useful guide for the policy makers in charge of the price-setting of fisheries products as well.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.7_8
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• pp.387-396
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• 2003

This paper provides an approximation algorithm for STP-MSP(Steiner Tree Problem with minimum number of Steiner Points).Because it seems to be impossible to have a PTAS(Polynomial Time Approximation Schemes), which gives the near optimal solutions, for the problem, the algorithm of this paper is an alternative that has the approximation ratio 2 with $n^{O(1)}$ run time. The importance of this paper is the potential to solve other related unsolved problems. The idea of this paper is to distribute the error allowance over the problem instance so that we may reduce the run time to polynomial bound out of infinitely many cases. There are earlier works[1,2] that show the approximations that have practical run times with the ratio of bigger than 2, but this paper shows the existence of a poly time approximation algorithm with the ratio 2.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.159-168
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• 2020

The cryptocurrency market has received immense consideration in media and academia since the beginning of 2013 because of its huge price fluctuation. This study focuses on Arab investors who invest in the cryptocurrency market by investigating the influence of behavioral finance factors on investment decisions in the cryptocurrency market. A quantitative approach was used by employing a snowball sampling method through 112 questionnaires. The results show that herding theory, prospect theory, and heuristic theory have a significant effect on investors' investment decisions in the cryptocurrency market. This emphasizes the significant role of the proposed behavioral factors as determinants of the investors' investment decisions. This study contributes to the existing research by consolidating the results of different researches in this study. It also contributes to the investors' understanding of the dynamics of the cryptocurrency market and it enhances the ability to make informed decisions based on their understanding. The implication of the findings will prepare hit and run investors to be progressively prepared to stay in the cryptocurrency market and develop their abilities on the most proficient method to settle on sound venture choices. Furthermore, the findings of this study will encourage financial specialists to realize that information on the traditional finance theory is not adequate to excel in the cryptocurrency market.

• Knowledge Management Research
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• v.21 no.1
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• pp.79-98
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• 2020

The majority of research on institutional theory suggests that the new institutional practices presented by national governments and expert groups is a legitimate demand by society, and that the organization is a passive actor that accepts it. However, individual organizations often perform so-called decoupling acts that run their organizations in their own way instead of following the way the system requires, despite the pressures of a strong institutional environment. In this study, the decoupling behavior of these organizations can be varied by the characteristics of the highest decision maker in the organization based on the upper-echelon theory(UET) even if there is no difference in pressure experienced by individual organizations, and their relationship is empirically analyzed among secondary educational institutions that are relatively strongly regulated by the government. According to the analysis of 192 high schools in Korea, the female principal, the younger the principal, and the higher the educational background, the more likely they are to engage in decoupling behavior that are different from the intent and content of government policies. Therefore, from the results of this study, meaningful theoretical and practical implications can be provided for researchers and managers in the field of knowledge management research.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.545-560
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• 2008

O Source import ㅁDirect import form Nastran, ANSYS ㅁDirect import of all the RPM from the files containing the structural results O Solver ㅁDirect computation of all RPM (multiple load case): one matrix resolution with multiple RHS ㅁEfficient solvers (MUMPS, SPARSE, Iterative) ㅁFrequency parallelisms available for very large problems O In practice ㅁSmall problems run on a desktop ㅁLarge problems can exceed 3kHz on a car engine O Easy to mesh ㅁ3D model created in a few minutes thanks to the unequal meshes. O And all Actran standard features

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.747-750
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• 1995

As railway trains run faster high performance braking system are necessary because more energy needs to be dissipated due to increased kinetic energy. In this work a portable computer based prediction system for emergency braking distance has been developed. The algorithm for the system is based on braking theory and empirical results of actual braking test. The computer is connected to the sensors to measure the velocity and the braking pressure in real train. It is expected that this system will be utilized to predict emergency braking distance during actual operation of the train

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.43.2-43.2
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• 2014

We present the three-dimensional genus topology of large-scale structure using the CMASS sample of the Final SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) data. To estimate the uncertainties in the measured genus, we very carefully construct mock CMASS surveys along the past light cone from the Horizon Run 3. We find that the shape of the observed genus curve agrees very well with the prediction of perturbation theory and with the mean topology of the mock surveys. However, comparison with simulations show that the observed genus curve slightly deviates from the theoretical Gaussian expectation. From the deviation, we further quantify the primordial non-Gaussian contribution.