• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.10
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• pp.509-515
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• 2000

This paper addresses a damping control strategy of Static Synchronous Series Compensator(SSSC) and analysis model for stability study. The effect of injected voltage source generated by SSSC is modelled as equivalent load. This model is thought to be reasonable for the stability study because the dynamics of SSSC is very fast compared with that of power system. Damping controller of SSSC is based on Transient Energy Function method. The proposed control strategy is insensitive to the operating conditions like power flow level because control law depends on the phase angles. The proposed analysis model and control strategy was confirmed by WSCC 9 bus system and two area system. Especially, the robustness of proposed control strategy is demonstrated with respect to multiple operating conditions in two area system.

• The Journal of Information Technology
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• v.12 no.3
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• pp.25-48
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• 2009

1. CONTENTS 1) RESEARCH OBJECTIVES The purpose of the study was to propose a future oriented urban space production strategy to offer diverse useful services to citizens to improve international competitiveness of cities in the times of competition that competitive subjects were changed from competition among countries to competition among cities. 2) RESEARCH METHOD In the proposed future-oriented urban space production strategy, the study compared/analyzed main plans related to development of urban space by selecting CBD(Jung-gu) of Busan out of local metropolises in South Korea. 3) RESEARCH FINDINGS In the proposed future-oriented urban space production strategy, the study largely sorted city's function into four scopes function of industrial support, function of social support, function of living support and function of urban infrastructure. 2. RESULTS It is expected that the proposed future oriented urban space production strategy will be utilized as a useful reference model when a lot of local governments, planning a ubiquitous urban space, establish a plan for constructing a ubiquitous urban space.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.4
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• pp.1426-1447
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• 2021

The payoff game between task publishers and users in the mobile crowdsensing environment is a hot topic of research. A optimal payoff selection model based on stochastic evolutionary game is proposed. Firstly, the process of payoff optimization selection is modeled as a task publisher-user stochastic evolutionary game model. Secondly, the low-quality data is identified by the data quality evaluation algorithm, which improves the fitness of perceptual task matching target users, so that task publishers and users can obtain the optimal payoff at the current moment. Finally, by solving the stability strategy and analyzing the stability of the model, the optimal payoff strategy is obtained under different intensity of random interference and different initial state. The simulation results show that, in the aspect of data quality evaluation, compared with BP detection method and SVM detection method, the accuracy of anomaly data detection of the proposed model is improved by 8.1% and 0.5% respectively, and the accuracy of data classification is improved by 59.2% and 32.2% respectively. In the aspect of the optimal payoff strategy selection, it is verified that the proposed model can reasonably select the payoff strategy.

• Journal of Power Electronics
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• v.16 no.2
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• pp.490-497
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• 2016

The analysis of the switch status of each unit module of a cascaded multi-level inverter reveals that the working condition of the switch of a chopper arm causes unnecessary switching under the conventional unipolar sinusoidal pulse width modulation (SPWM). With an increase in the number of cascaded multilevel inverters, the superposition of unnecessary switching gradually occurs. In this work, we propose an improved SPWM strategy to reduce switching in cascaded multilevel inverters. Specifically, we analyze the switch state of the switch tube of a chopper arm of an H-bridge unit. The redundant switch is then removed, thereby reducing the switching frequency. Unlike the conventional unipolar SPWM technique, the improved SPWM method greatly reduces switching without altering the output quality of inverters. The conventional unipolar SPWM technique and the proposed method are applied to a five-level inverter. Simulation results show the superiority of the proposed strategy. Finally, a prototype is built in the laboratory. Experimental results verify the correctness of the proposed modulation strategy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1546-1564
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• 2012

Pattern-based query processing has not attracted much attention in wireless sensor network though its counterpart has been studied extensively in data stream. The methods used for data stream usually consume large memory and much energy. This conflicts with the fact that wireless sensor networks are heavily constrained by their hardware resources. In this paper, we use piece wise representation to represent sensor nodes' collected data to save sensor nodes' memory and to reduce the energy consumption for query. After getting data stream's and patterns' approximated line segments, we record each line's slope. We do similar matching on slope sequences. We compute the dynamic time warping distance between slope sequences. If the distance is less than user defined threshold, we say that the subsequence is similar to the pattern. We do experiments on STM32W108 processor to evaluate our strategy's performance compared with naive method. The results show that our strategy's matching precision is less than that of naive method, but our method's energy consumption is much better than that of naive approach. The strategy proposed in this paper can be used in wireless sensor network to process pattern-based queries.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.361-372
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• 2021

This research aimed to analyze the momentum strategy of foreign investors with the smallest trading transactions in the Indonesian stock market. This study applied a quantitative method approach using intraday transaction data of companies listed on the LQ-45 Index for March, April, and May 2017, obtained from the Indonesia Capital Market Institute (TICMI) which is a subsidiary of the Indonesia Stock Exchange (IDX). The number of companies with available data is 35 companies, consisting of 23 non-government stocks and 12 government stocks. The number of observations from the 35 companies was 8,686,030 observations where the government companies recorded 2,751, 545 and the non-government companies 1,387,016 observations. All data was then squeezed and grouped into small, medium, and large trade transaction orders. The data analysis method used was paired t-test with SPSS to analyze cumulative abnormal returns in the formulation and test periods. This study found that small foreign investors carried out momentum strategies on stocks listed on the LQ-45 Index. However, re-testing was done by separating government and non-government shares. It turned out that small foreign investors performed a momentum strategy on non-government and a contrarian strategy on government.

• The Journal of the Korea Contents Association
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• v.12 no.1
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• pp.138-145
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• 2012

, Korea's popular television comedy program cast the strategy of making fun by word game interweaving meaning and nonmeaning and started to making fun by narrative game. So called Digital Narrative strategy seems to reflect the changes of social trends. Getting verisimilitude by detail description, parody realism, hierarchy of word body naked, anxiety for influence or star cameo seems to be principal strategy. With a minute realism strategy, new method of making meaning appropriate to digital era seems to appear.

• Journal of Information Science Theory and Practice
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• v.10 no.spc
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• pp.76-85
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• 2022

At the 8th National High-Performance Computing (HPC) Committee convened in 2021, the "National High-Performance Computing Innovation Strategy (draft) for the 4th Industrial Revolution Era" was deliberated and the original draft was approved. In this proposal, the Ministry of Science and ICT in KOREA announced three major plans and nine detailed projects with the vision of "Realizing the 4th industrial revolution quantum jumping by leaping into a high-performance computing powerhouse." Thereby the most important policy about national mid-term and long-term HPC development was established and called the HPC innovation strategy (hereinafter "the innovation strategy"). The three plans of the innovation strategy proposed by the government are: Strategic HPC infrastructure expansion; Secure source technologies; and Activate innovative HPC utilization. Each of the detailed projects has to be executed nationally and strategically. In this paper, we propose a strategy for the implementation of two items ("Strategic HPC infrastructure expansion" and "activate innovative HPC utilization") among these detailed plans.

• 한국경영정보학회:학술대회논문집
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• 2008.06a
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• pp.270-275
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• 2008

The various research on Communities of practices (CoP) for propagation of softer type knowledge in new Knowledge Management (KM) strategy having been performed for past couple of years. CoP is one of effective process innovation tool for diffusion of knowledge. Based on CoP's voluntary and spontaneous characteristic, it performs a function of delivering softer type knowledge of workers to the other colleagues of organization. But one step further to CoP's function of propagation of internal knowledge, research on function of CoP's contribution in enterprise strategy are insufficient yet. This paper presents enterprise CoP should be managed and aligned to strategic objectives of enterprise, and also, suggests the methodology for CoPs to maintain a lifecycle as a tool to contribute in strategic goal attainment. Although CoPs are voluntary and spontaneous informal organization, it can display a contribution as tool for KM strategy when it is aligned to strategy properly and form efficient lifecycle.

• Journal of Korea Multimedia Society
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• v.4 no.6
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• pp.543-553
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• 2001

In this paper, we proposed management strategy of medical image data in order to solve the problem in traditional medical images migration method. As management strategy of medical image data we proposed EAT(Expanded Average Transaction time) data migration method and data storing method based on temporal interrelation. In EAT data migration strategy, we define the dividing criterion which distinguish entity versions to be stored in each storage and also define entity versions to be stored in each storage. We defined degree of overlap and degree of difference for any two entity versions, and integrated those values and described method which place entity versions to storage. In order to compare the number of cluster references when we change rate of temporal queries, the number of cluster references of proposed method is smaller than that of traditional method.