• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.104-111
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• 1997

In this paper, three-phase PWM AC to DC boost converter that operates with unity power factor and sinusodial input line currents is presented. The current control of this converter is based on the space vector PWM strategy with fixed switching frequency and the line currents track to reference currents within one sampling time interval. By using this control strategy low ripples in the outut current and the voltage as well as fast dynamic response are achieved with small dc link cpacitance employed.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.958-961
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• 1998

In this paper, a three phase boost converter that operates with unity power factor and sinusodial input currents is presented. The current control of the converter is based on the space vector strategy with fixed switching frequency and the input current tracks the reference current within one sampling time interval. Space vector strategy for current control was materialized as a digital control method by using DSP. By using this control strategy low ripples in the output voltage, low harmonics in the input current and fast dynamic responses are achieved with a small capacitance in the dc link.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.11
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• pp.156-163
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• 1997

Recently, the three phase AC to DC boost converter has become one of the most widely used power converters as DC power source in the industry applications. In this paepr, a three phase PWM AC toDC boost converter that operates with unity power factor and sinusodial input currents is presented. The current control of the converter is based onthe predicted current control strategy with fixed switching frequency and the input current tracks the reference cuent within one sampling time interval. Therefore, by using this control strategy low ripples in the output voltage, low harmonics in the input current and fast dynamic responses are achieved with a small capacitance in the DC link.

• Korean Journal of Child Studies
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• v.28 no.5
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• pp.73-89
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• 2007

The purpose of this study was to develop a reliable and valid instrument to assess Korean teachers' strategies for addressing challenging behaviors of preschoolers. The Teacher Strategy Questionnaire(TSQ) consisting of 34 items was developed with three theoretically driven factors(positive proactive, positive reactive, and negative reactive strategies). Participants were 238 preschool and daycare center teachers who responded to the TSQ. Validity and reliability of the TSQ were explored using Cronbach's $\alpha$, item analysis, and factor analyses. The reliability of the TSQ was relatively high, ranging from .74 to .85. No item needed to be eliminated. Among the three pre-structured factors of the TSQ, one positive proactive factor was identified as having two innate factors.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.114-116
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• 2018

This paper presents a control strategy to achieve the balanced sinusoidal output currents, as well as sinusoidal input currents for the matrix converter (MC) under unbalanced input voltages. By regulating the modulation index of the converter according to the instantaneous input voltages, the output currents are kept balanced and sinusoidal. In order to obtain sinusoidal input currents, the input power factor angle should be dynamically calculated based on the positive and negative sequence components of the input voltages. This paper proposes a simple method to construct the expected input power factor angle without the complicated sequence component extraction of input voltages. Simulation results are given to validate the effectiveness of the proposed control strategy.

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.20-37
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• 2002

In this paper, we studied the purpose of this paper is like that; the first one is to find the factors associated with operational strategy by variable website types classified into information-providing type, product-providing type and service- providing type by user approach purposes. The second one is to propose the successful operational strategy through analyzing the factors affecting the financial and non-financial performance of websites. A framework of research model including above factors is developed and tested statistically. The data are collected from Internet website experts of 80 Korean firms through survey. The main results of this research are as follows. First, in information-providing websites, the community factor is regarded as the most important factor But for the Improvement of the performance, not only community factor but also user interface, customization, total quality and playfulness factors should be regarded as important factors equally. Second, in product-providing websites, customization, total quality and visual design factors are regarded as important factors. But for the improvement of the performance, community and visual design factors should be regarded as important factors. Third, in service-providing websites, user interface, customization and community factors should be regarded as important factors in order to improve the performance.

• The Korean Journal of Applied Statistics
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• v.20 no.1
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• pp.23-38
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• 2007

Corporations adopt a segmentation depends on the existence of target variables, in general. In this paper, for the case of no target variables, a strategy through segmentation is proposed for corporations having a special status based on the management index. In case of segmentation using cluster analysis, however, if one classify according to many variables then he will be in face of difficulties in characterizing. Therefore, after extracting representative factors by factor analysis, a segmentation method through 2 step cluster analysis is employed on the basis of these representative factors. As a result, six segmentation groups are found and the resulting strategy is proposed which strengthens prominent factors and makes up defective factors for each group.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.2
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• pp.191-204
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• 2010

There is a well-defined propagation model, named the random constant spread (RCS) model, which explains worms that spread their clones with a random scanning strategy. This model uses the number of infected hosts in a domain as a factor in the worms' propagation. However, there are difficulties in explaining the characteristics of new Internet worms because they have several considerable new features: the denial of service by network saturation, the utilization of a faster scanning strategy, a smaller size in the worm's propagation packet, and to cause maximum damage before human-mediated responses are possible. Therefore, more effective factors are required instead of the number of infected hosts. In this paper, the network bandwidth usage rate is found to be an effective factor that explains the propagations of the new Internet worms with the random scanning strategy. The analysis and simulation results are presented using this factor. The simulation results show that the scan rate is more sensitive than the propagation packet for detecting worms' propagations.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.217-228
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• 2018

It is aimed at providing a guide for effective ERP implementation strategy in view of the need for differentiation and cost advantage strategy from competitors in introducing ERP centered on SMEs. The results show that differentiation and cost superiority and service quality are dependent on the introduction performance and mediating effect. First, the differentiation or cost advantage strategy supports the previous research results in financial performance. However, in the differentiation strategies, only the non-financial aspects were noted. Second, the differentiation and cost advantage strategy were analyzed to have financial performance only in the assurance of service quality factor and the remaining service quality was not significant in the introduction performance. Third, the mediating effect of consulting service quality was analyzed in terms of differentiation or cost advantage Did not do it. In conclusion, system construction is different from financial perspective in terms of construction strategy. In service quality factor, it affects the confidence that supplier provides, knowledge and confidence, and ability to give faith.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.299-309
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• 2022

Human factor represents a very challenging issue to organizations. Human factor is responsible for many cybersecurity incidents by noncompliance with the organization security policies. In this paper we conduct a comprehensive review of the literature to identify strategies to address human factor. Security awareness, training and education program is the main strategy to address human factor. Scholars have consistently argued that importance of security awareness to prevent incidents from human behavior.