• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1484-1494
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• 2017

We present a two-stage inverter with high step-up conversion ratio engaging modified finite-set Model Predictive Control (MPC) for utility-integrated photovoltaic (PV) applications. The anticipated arrangement is fit for low power PV uses, the calculated efficiency at 150 W input power and 19 times boosting ratio was around 94%. The suggested high-gain dc-dc converter based on Cockcroft-Walton multiplier constitutes the first-stage of the offered structure, due to its high step-up ability. It can boost the input voltage up to 20 times. The 3S current-source inverter constitutes the second-stage. The 3S current-source inverter hires three semiconductor switches, in which one is functioning at high-frequency and the others are operating at fundamental-frequency. The high-switching pulses are varied in the procedure of unidirectional sine-wave to engender a current coordinated with the utility-voltage. The unidirectional current is shaped into alternating current by the synchronized push-pull configuration. The MPC process are intended to control the scheme and achieve the subsequent tasks, take out the Maximum Power (MP) from the PV, step-up the PV voltage, and introduces low current with low Total Harmonic Distortion (THD) and with unity power factor with the grid voltage.

• 한국IT서비스학회지
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• 제19권5호
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• pp.83-91
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• 2020

Language Models such as BERT has been an important factor of deep learning-based natural language processing. Pre-training the transformer-based language models would be computationally expensive since they are consist of deep and broad architecture and layers using an attention mechanism and also require huge amount of data to train. Hence, it became mandatory to do fine-tuning large pre-trained language models which are trained by Google or some companies can afford the resources and cost. There are various techniques for fine tuning the language models and this paper examines three techniques, which are data augmentation, tuning the hyper paramters and partly re-constructing the neural networks. For data augmentation, we use no-answer augmentation and back-translation method. Also, some useful combinations of hyper parameters are observed by conducting a number of experiments. Finally, we have GRU, LSTM networks to boost our model performance with adding those networks to BERT pre-trained model. We do fine-tuning the pre-trained korean-based language model through the methods mentioned above and push the F1 score from baseline up to 89.66. Moreover, some failure attempts give us important lessons and tell us the further direction in a good way.

• Journal of Power Electronics
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• 제18권2호
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• pp.407-417
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• 2018

A novel family of Buck mode three-level direct ac converters with a high frequency link is proposed. These converters can transfer an unsteady high ac voltage with distortion into a regulated sinusoidal voltage with a low THD at the same frequency. The circuit configuration is constituted of a three-level converter, high frequency transformer, cycloconverter, as well as input and output filters. The topological family includes forward, push-pull, half-bridge, and full-bridge modes. In order to achieve a reliable three-level ac-ac conversion, and to overcome the surge voltage and surge current of the cycloconverter, a phase-shifted control strategy is introduced in this paper. A prototype is presented with experimental results to demonstrate that the proposed converters have five advantages including high frequency electrical isolation, lower voltage stress of the power switches, bi-directional power flow, low THD of the output voltage, and a higher input power factor.

• International Journal of Human Ecology
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• 제12권1호
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• pp.75-85
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• 2011

This study aims to understand the experiences as consumers of Thai students studying in Korea. "Study Korea Project" which is a drive to globalize local universities by attracting more oversea students as a pull factor, and economic growth, values on education and Hallyu as push factors contribute to the increase the number of Thai students in Korea. In order to understand the experiences of Thai students as consumers studying in Korea, individual interviews were conducted. A total of 5 participants were asked about meaning of consumption in everyday life in Korea or any changes in consumption behavior compared to living in Thai. Three themes were identified through wholistic and selective approaches. First, all participants in the study said that they were surprised because of high living expense in Korea. Consequently, survival itself is too much for them and they have become more conscious of prices of goods. Secondly, since most participants in this study can control their own budget, they feel some degree of freedom and power of control of their own lives. This experience may help them to accomplish their developmental tasks during the transition to adulthood. Thirdly, they are easily imbued with Korean consumer culture. It causes various conflicts between buying and not-buying or friends gathering and saving money. Sometimes it makes them in stuck excessive consumption and financial problems. For a deeper understanding of oversea students' lives in Korea as consumers, further studies should take into consideration of not only their culture of origins, but also misconceptions that have accumulated around these students.

• 지식경영연구
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• 제18권1호
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• pp.159-176
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• 2017

Recently, the popularity of smartphones has led to a dramatic increase in the frequency of use of App(Application) services. LBS (Location-Based Service) App service adopts various methods such as push marketing and useful information by region through providing location-based service based on the location of the consumer. In particular, an enterprise or an App management company can provide necessary information to the consumer through the necessary information among the customer related knowledge information obtained by utilizing the location information of the consumer in real time. Nevertheless, since LBS is a service that can be performed only when the company obtains consent to provide location information voluntarily by the consumer, there is a case of privacy infringement due to consumers' use of personal information. The purpose of this study is to identify the characteristics of privacy related variables and the knowledge structure for consumer value formation based on the theory of privacy calculation. We also compared the characteristics of Korea with those of China in privacy issue. As a result of the analysis, it was confirmed that factors such as information utilization ability and information control ability were influential as a key factor of privacy calculation. In addition, perceived value influences the reputation of the LBS App service.

• 복식
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• 제53권6호
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• pp.87-99
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• 2003

The purpose of this study was to investigate the purchase behavior of fashion merchandise and purchase evaluative criteria in regard to apparel type of Chinese women consumers, and to provide effective basic data for push into the Chinese market. The subject used for the study were 20-40 aged women living in china. 848 data were analyzed factor analysis, one-way ANOVA. t-test and correlation with SPSS package. The results of this study were as follows. 1. As the purchase behavior of fashion merchandise of Chinese women consumers were found out four groups of factors that were named "pursuit mass media", "pursuit fashion", "pursuit brand", and "pursuit price". 2. Chinese women consumers bought fashion merchandise with evaluating three groups of factors that were "for functional", "for aesthetic" and "for external". 3. The purchase behavior of fashion merchandise of Chinese women consumers was correlated with purchase evaluative criteria.nese women consumers was correlated with purchase evaluative criteria.

• 한국산업융합학회 논문집
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• 제12권2호
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• pp.85-90
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• 2009

The Toyota production system (TPS) developed by Toyota corporation is a management principle and production model to improve values added through elimination of waste. Since the oil shock in 1970s, the TPS has drawn the worldwide attentions as a main factor of competitiveness of Japanese manufacturing system and has been studied and implemented in many countries regardless of size and types of industry. For the correspondence to various customer's requirement, it is required to establish on time delivery procedure and to shorten lead time. Therefore it intended to establish TPS which is adopted to 7 losses reduction and JIT(Just in Time). In this paper, the automatic production line for color TV manufacturing by TPS was developed and proved to push up two times of productivity, to reduce the 25 workers at a time, and to widen the flexibility of manufacturing from 14" to 25" TV.

• 정보처리학회논문지C
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• 제9C권1호
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• pp.17-20
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• 2002

IMT-2000망 핵심기술은 mobile IP를 이용하는 북미의 3G packet data system과 GSM망과 연계를 하는 유럽의 GPRS로 구분할 수 있다. 이러한 IMT-2000망 핵심기술은 글로벌한 로밍을 위해 Mobile IP도입을 추진하고 있다. Mobile IP상에서는 RADIUS나 DIAMETER같은 AAA 서버가 다이얼 업 컴퓨터의 인증, 허가 서비스를 제공하기 위해 사용되고 있는데, 이것은 MN에게 매우 중요하다. Mobile IP는 MN과 HA간에 강력한 인증을 요구하기 때문이다. 본 논문에서는 이러한 IMT-2000 환경에서 고려되고 있는 Smooth Handoff 기법에서 효과적인 AAA프로토콜의 적용에 관하여 논한다.

• 한국정보시스템학회지:정보시스템연구
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• 제30권4호
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• pp.43-69
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• 2021

Purpose Although companies occupied the network market take the advantageous position first and can be successful in securing users over a certain size, it is important to satisfy the customers' demand and prevent the outflow of users toward a new alternative SNS. What is more, there are frequent changes in the flow of users toward new SNSs. Despite these dynamic market circumstances, there is a lack of research to explain the switching behaviors of SNS users. Design/methodology/approach The objective of this study is to explain and verify a specified migration theory(Push-Pull-Mooring model) focused on SNS fatigue in the psychological point of view, as well as reviewing previous studies on functional and technical characteristics of SNSs themselves. Moreover, this study tried to highlight factors affecting users actual SNS switch rather than their switching intention. Findings According to the statistical analysis, the most influenced pull factor to switch SNS was the alternative attractiveness. On the other hand, undesired relationship burden, service innovation and important mooring factors to prevent users' SNS switch. This study has a significant contribution to the theory, which analyzed users' actual SNS switch, and examined SNS users' psychological factors(SNS fatigue), reviewing the characteristics of existing services. To secure more users and to keep them, companies providing social network service need to develop differentiated strategies by analyzing psychological characteristics of various users.

• 유통과학연구
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• 제20권6호
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• pp.21-32
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• 2022

Purpose: This study aims to test the influence of brand relationship, price, content, brand awareness, and electronic Word-Of-Mouth (eWOM) on willingness to pay for the subscription fee of Disney+ Hotstar. As the latest streaming service provider in Indonesia, Disney + Hotstar under Disney Media and Entertainment Distribution has actively conducted strategies to strengthen the brand and attract consumers. Research design, data and methodology: Structural Equation Modelling with WarpPLS approach was used to assess the proposed model gathering data from 316 people who have ever known about Disney+ Hotstar through an online survey using measurement items from previous literature. Results: Most responses were obtained from millennial generations. Findings demonstrated that brand relationships, price, content, and brand awareness positively influenced willingness to pay for the subscription fee whereas eWOM showed a negative and insignificant influence on the willingness to pay for the subscription fee. Conclusions: The most significant factor towards willingness to pay a for subscription fee is price, followed by brand awareness, brand relationship, and content. The result of this study may be used as a guide for professionals in the streaming service industry to better implement their strategies in influencing people to have the willingness to subscribe.