• The Transactions of the Korean Institute of Electrical Engineers B
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• 제54권4호
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• pp.208-216
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• 2005

Recently, the study of islanding phenomenon, maintains its operation even when the utility grid is removed has lead to the trend of utility interactive inverters in photovoltaic generation systems. In this paper, a novel Anti-islanding method is presented. the proposed method can keep the real average power component constant by MPPT control and cause the load current frequency with only change of reactive power component under the islanding condition. its periodical change of Reactive power component can decrease the NDZ(Non-Detective zone) so that the detection of various loads will be possible. the insufficient effect if additional reactive power component to the grid is proved theoretically and the islanding detection is also confirmed from a experimental result with a inverter for 3kW photovoltaic generation system applied the proposed Anti-islanding method.

• Journal of Power Electronics
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• 제14권4호
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• pp.712-721
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• 2014

This paper introduces a simple grid-voltage-sensorless control scheme for single-phase power factor correction (PFC) boost converters. The grid voltage waveform is obtained based on the dc output voltage, the switching duty ratio, and a phase-lead compensator. In addition, the duty ratio feedback is utilized to obtain the unity input power factor and the zero harmonic current. The proposed control scheme is designed and mathematically analyzed based on a small-signal model of PFC boost converters. To verify the effectiveness of the proposed control scheme, several simulations and experiments are carried out in two applications: an industrial power system with a 60 Hz grid frequency and a commercial aircraft application with a 400 Hz grid frequency.

• Journal of Information Processing Systems
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• 제15권2호
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• pp.239-250
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• 2019

An individual's health data is very sensitive and private. Such data are usually stored on a private or community owned cloud, where access is not restricted to the owners of that cloud. Anyone within the cloud can access this data. This data may not be read only and multiple parties can make to it. Thus, any unauthorized modification of health-related data will lead to incorrect diagnosis and mistreatment. However, we cannot restrict semipublic access to this data. Existing security mechanisms in e-health systems are competent in dealing with the issues associated with these systems but only up to a certain extent. The indigenous technologies need to be complemented with current and future technologies. We have put forward a method to complement such technologies by incorporating the concept of blockchain to ensure the integrity of data as well as its provenance.

• Journal of Korea Game Society
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• 제21권2호
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• pp.151-160
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• 2021

Alternate reality games (ARGs) are a game genre with characteristics that can lead to changes in current integrated media environments. While technical combinations are being pursued as diverse media are utilized based on formative aspects, the representative, narrative combination of the real and the virtual is a convergent factor in narrative structures. Through perspectives that perceive transmedia storytelling-which has brought convergence to communication among gamers-as having a structure and utility that can outclass previous game forms, this study focuses on ARGs, which have features that converge reality and virtual reality. Further, the study reveals the structure and utility of that system. This study sheds light convergent storytelling, which is in demand in the transmedia age, and which will serve as a significant investigation with regard to social perceptions of future games and changes in game form.

• Archives of Plastic Surgery
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• 제49권3호
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• pp.360-364
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• 2022

Although capsular contracture represents one of the most important complications after breast augmentation, local inflammation and fibrosis can lead, to capsular calcification, an often-forgotten radiological sign of capsular contracture. In this article, the authors present a clinical case of breast implant calcification in an 81-year-old patient. Although this complication has been rarely described, the literature was reviewed to clarify the role of the local microenvironment in capsular contracture and calcification. At present, capsular contracture patients are classified using the conventional Baker score and the histological Wilflingseder classification. As it was not possible to consider capsular calcification when classifying our patient using the traditional scores, the authors propose an updated version of the current scale.

• Asia Marketing Journal
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• 제21권4호
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• pp.45-57
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• 2020

With the development of new technologies, virtual reality (VR) is emerging as a new consumer marketing platform. Yet, only a few studies have investigated VR in the consumption context. The current research explores how experiencing a product through VR influences consumer attitude and purchase intention for the product. Although assessing products in real life is believed to be more diagnostic than that through VR, the present research revealed that experiencing a product through VR could lead to a more positive attitude toward and higher purchase intention for the product. We also demonstrated that "enjoyment" has a mediating effect while evaluating the product through VR. To compare product experience through VR to that in real life, we employed the HTC Vive VR system to implement a VR environment. In the VR condition, participants evaluated plastic building blocks using a VR headset and a motion controller; and in the real life (reality) condition, they evaluted plastic building blocks printed using a 3D printer to make them look exactly the same as the blocks used in the VR condition. Finally, implications and suggestions are discussed.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3787-3800
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• 2023

Reactivity Initiated Accident (RIA) scenarios require special attention using advanced simulation techniques due to their complexity and importance for nuclear power plant (NPP) safety. While the conservative approach has traditionally been used for safety analysis, it may lead to unrealistic results which calls for the use of best estimate plus uncertainty (BEPU) approach, especially with the current advances in computational power which makes the BEPU analysis feasible. In this work an Uncontrolled Control Element Assembly (CEA) Withdrawal at Full Power accident scenario is analyzed using the BEPU approach by loosely coupling the thermal hydraulics best-estimate system code (RELAP5/SCDAPSIM/MOD3.4) to the statistical analysis software (DAKOTA) using a Python interface. Results from the BEPU analysis indicate that a realistic treatment of the accident scenario yields a larger safety margin and is therefore encouraged for accident analysis as it may enable more economic and flexible operation.

• Information Systems Review
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• 제9권1호
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• pp.139-160
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• 2007

Our study focuses on empirical findings of the critical factors which influence the performance of ERP system in business. The study is mainly interested in examining the influence of the characteristics of late process of adopting ERP called "Go-Live" phase with the critical issues like customizing, transformational process of standardization, phased implementation, concurrent operation and use with the current systems on users' ERP satisfaction. The analyses of the data conducted thru moderated regression analysis and subgroup analysis. Using moderated regression analysis, we first examined the effect of moderator variables like customizing, process standardization, sequential use, concurrent use with the current systems. And then, using subgroup analysis is to verify directions of the moderator effects. Having knowledge on the characteristics of ERP Go-Live process can lead to success of ERP system in business. Our results can be beneficial to those organizations who want to adopt and maintain ERP system effectively.

• The Journal of the Convergence on Culture Technology
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• 제7권4호
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• pp.291-297
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• 2021

The current formal and memorized design repetition training and practice is wandering in the uniform flat design thinking expression. To change these two-dimensional current issues into a three-dimensional design method, set the direction for each grade level under the integrated convergence educational goal and carry out projects step by step to understand design, the principle of spatial composition, the introduction of traditional design history, and the overall design of craft design. Creative and practical skills such as approach should be cultivated. Designers can only be produced through systematic education and training. In order to lead society and succeed, a designer who has experienced solutions and countermeasures on how to adapt themselves to the demands of various changes in the times must come to the field. Education experts insisted on innovation of the organizational structure and subject of the education system, and emphasized the importance of education in response to the rapid pace of change in the 21st century. This study aims to propose an educational system that combines academic research with a structural approach to tasks by setting a project that reflects the needs of society for convergence practice in which design and adjacent disciplines are linked through understanding and analysis of these issues.

• Smart Structures and Systems
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• 제30권4호
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• pp.339-351
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• 2022

Evaluating the current condition of existing structures is of primary importance for economic and safety reasons. This can be addressed by Structural System Identification (SSI). A reliable static SSI depends on well-designed sensor configuration and loading cases, as well as efficient parameter estimation algorithms. Static SSI by the Measurement Error-Minimizing Observability Method (MEMOM) is a model-based deterministic static SSI method that could estimate structural parameters from static responses. In the current state of the art, this method is only applicable when structures are subjected to one loading case. This might lead to lack of information in some local regions of the structure (such as the null curvatures zones). To address this issue, the SSI by MEMOM using multiple loading cases is proposed in this work. Observability equations obtained from different loading cases are concatenated simultaneously and an optimization procedure is introduced to obtain the estimations by minimizing the discrepancy between the predicted response and the measured one. In addition, a Genetic-Algorithm (GA)-based Optimal Sensor Placement (OSP) method is proposed to tackle the OSP problem under multiple static loading cases for the very first time. In this approach, the Fisher Information Matrix (FIM)'s determinant is used as the metric of the goodness of sensor configurations. The numerical examples of a 3-span continuous bridge and a 13-story frame, are analyzed to validate the applicability of the extended SSI by MEMOM and the GA-based OSP method.