• The Journal of Industrial Distribution & Business
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• v.7 no.2
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• pp.13-20
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• 2016

Purpose - The purpose of this research is to discover whether the presence of the product average rating introduces biases or change the way people perceive information. We posit that review's overall rating has a predisposition effect on consumers' perception towards detailed review information. Research design, data, and methodology - To test these hypotheses, we conducted an empirical study on a real-world setting of online shopping platform. We choose the Amazon website to test our results. The data we use were collected by the Stanford Network Analysis Project1 (McAuley et al., 2013). Results - With a dataset containing reviews of seven product categories from amazon.com., our findings could possess more generalizability as they are produced on the typical and influential online market. Second, as our research provides alternative views of consumers' shopping behavior, it is better to test our hypotheses by data from the same source. Conclusions - Our study reveals the impact of the collective rating presence on consumers' diagnosticity perception and sheds light upon some of the conflictive results in prior studies. Our research generates implications to both theories and business practices, and suggests future directions for the research question.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.303-308
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• 2005

A miniaturized time-of-flight mass spectrometer with an electron impact ionization source and sheet membrane introduction has been developed. The advantages and features of this mass spectrometer include high sensitivity, simple structure, low cost, compact volume with field portability, and ease of operation. A mass resolution of 400 at m/z 78 has been obtained with a 25 cm flight path length. Under optimized conditions, the detection limits for the volatile organic compounds (VOCs) studied were 0.2-10 ppm by volume with linear dynamic ranges greater than three orders of magnitude. The response times for various VOCs using a silicone membrane of 127 $\mu$m thickness were in the range 4.5-20 s, which provides a sample analysis time of less than 1 minute. These results indicate that the membrane introduction/time-of-flight mass spectrometer will be useful for a wide range of field applications, particularly for environmental monitoring.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.210-216
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• 2009

Distributed Generation (DG) is predicted to play a important role in electric power system in the near future. insertion of DG system into existing distribution network has great impact on real-time system operation and planning. It is widely accepted that micro turbine generation (MTG) systems are currently attracting lot of attention to meet customers need in the distributed power generation market. In order to investigate the performance of MT generation systems, their efficient modeling is required. This paper presents the modeling and simulation of a MT generation system suitable for stand-alone operation. The system comprises of a permanent magnet synchronous generator driven by a MT. A brief description of the overall system is given, and mathematical models for the MT and permanent magnet synchronous generator are presented. Also, the use of power electronics in conditioning the power output of the generating system is demonstrated. Simulation studies with MATLAB/Simulink have been carried out in stand-alone operation mode of a DG system.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2687-2698
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• 2020

Most of the machine learning-based intrusion detection tools developed for Industrial Control Systems (ICS) are trained on network packet captures, and they rely on monitoring network layer traffic alone for intrusion detection. This approach produces weak intrusion detection systems, as ICS cyber-attacks have a real and significant impact on the process variables. A limited number of researchers consider integrating process measurements. However, in complex systems, process variable changes could result from different combinations of abnormal occurrences. This paper examines recent advances in intrusion detection algorithms, their limitations, challenges and the status of their application in critical infrastructures. We also introduce the discussion on the similarities and conflicts observed in the development of machine learning tools and techniques for fault diagnosis and cybersecurity in the protection of complex systems and the need to establish a clear difference between them. As a case study, we discuss special characteristics in nuclear power control systems and the factors that constraint the direct integration of security algorithms. Moreover, we discuss data reliability issues and present references and direct URL to recent open-source data repositories to aid researchers in developing data-driven ICS intrusion detection systems.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4422-4430
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• 2022

Studying the effects of gamma radiation on the instrumentation and control (I&C) system of a nuclear power plant is critical to the successful and reliable operation of the plant. In the accidental scenario, the adverse environment of ionizing radiation affects the performance of the I&C system and it leads to inaccurate and incomprehensible results. This paper reports the effects of gamma radiation on the AT89C51RD2, a commercial-off-the-shelf 8-bit high-performance flash microcontroller. The microcontroller, selected for the device under test for this study is used in the remote terminal unit for a nuclear power plant. The custom circuits were made to test the microcontroller under different gamma doses using a ⁶⁰Co gamma source in both ex-situ and in-situ modes. The device was exposed to a maximum dose of 1.5 kGy. Under this hostile environment, the performance of the microcontroller was studied in terms of device current and voltage changes. It was observed that the microcontroller device can operate up to a total absorbed dose of approximately 0.6 kGy without any failure or degradation in its performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2399-2418
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• 2023

The paper focuses on investigating secure transmission in wireless powered communication networks (WPCN) that involve multiple energy-constrained relays and one energy-constrained source. The energy is harvested from a power beacon (PB) while operating in the presence of a passive eavesdropper. The study primarily aims to achieve energy-efficient secure communications by examining the impact of channel estimation on the secrecy performance of WPCN under both perfect and imperfect CSI scenarios. To obtain practical insights on improving security and energy efficiency, we propose closed-form expressions for secrecy outage probability (SOP) under the linear energy harvesting (LEH) model of WPCN. Furthermore, we suggest a search method to optimize the secure energy efficiency (SEE) with limited power from PB. The research emphasizes the significance of channel estimation in maintaining the desired performance levels in WPCN in real-world applications. The theoretical results are validated through simulations to ensure their accuracy and reliability.

• The Research Journal of the Costume Culture
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• v.28 no.4
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• pp.446-462
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• 2020

The objectives of this study are to explore the information source, assessment, and preferred styles of 3D virtual influencers(VI), to investigate the expected impact of advertisements with 3D VIs on brands, and to explore ways of expanding the use of 3D VIs. In-depth interviews with 40 males and females in their 20s and 30s were conducted and qualitative data were analyzed. The study results are summarized as follows. First, the information source of the 3D VI was SNS, acquaintances, and broadcasting. Second, 3D VIs were considered positively due to their attractive appearance, wide utilization, innovative use, freshness, separation from private identity, and time and cost savings, while considered negatively due to their unrealistic appearance and antipathy against replacing a person's role. Third, the preferred appearance styles of the 3D VI differed according to the level of virtuality although the majority of interviewees preferred similar looks to real people with low virtuality. Fourth, diverse image qualities such as innovative, differentiated, trendy, high-value, professional, and future-oriented were considered as transferred to the brand advertised by 3D VIs. Fifth, advertisements with 3D VIs may help build positive perceptions of advertised brands that may lead to purchase behaviors for some consumers. Lastly, to expand the use of 3D VIs, the specific advantages of virtual models should be maximized with consideration of how to implement a variety of body types and images of models. Findings present an important foundation to generate strategies to better apply 3D VIs to the fashion market.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.8
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• pp.950-958
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• 2019

Digital Social Innovation, social innovation utilizing digital technology, is gaining attenntion as an innovative new way of solving pressing social problems such as ageing, traffic, unemployment etc. while some raise concerns as to the negative impact of digital technology on society associated with Share-the-Scraps-economy and On-demand-economy. The paper aims to address these concerns by examining the nature and source of business values generated in digital social innovation. Donation, cooperation/solidarity and sharing are identified as sources of business value from social innovation. Digitization, Platform may present infrastructure upon which efficiency of economic transaction can be elevated. The participation of consumers/users in the value chain and value network enabled by digital technology is identified and discussed as the critical source of business value in digital social innovation. The business model of Docksan-dong Happy Parking Street living lab project is analysed to illuminate the realization of business vaules in real life setting. Policy recommendations and future research directions are suggested.

• International Journal of Aeronautical and Space Sciences
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• v.10 no.1
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• pp.98-103
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• 2009

The forecasting, mitigation and preparedness of the natural disaster impacts require relevant information regarding the disaster desirable in real time. In the meantime it is requiring the rapid and continuous data and information generation or gathering for possible prediction and monitoring of the natural disaster. Since disasters that cause huge social and economic disruptions normally affect large areas or territories and are linked to global change. The use of traditional and conventional methods for management of the natural disaster impact can not be effectively implemented for intial data col1ection with the further processing. The space technology or remote sensing tools offer excellent possibilities of collecting vital data. The main reason is capability of this technology of collecting data at global and regional scales rapidly and repetitively. This is unchallenged advantage of the space methods and technology. The satellite or remote sensing techniques can be used to monitor the current situation, the situation before based on the data in sight. as well as after disaster occurred. They can be used to provide baseline data against which future changes can be compared while the GIS techniques provide a suitable framework for integrating and analyzing the many types of data sources required for disaster monitoring. Developed GIS is an excellent instrument for definition of the social impact status of the natural disaster which can be undertaken in the future database developments. This methodology is a good source for analysis and dynamic change studies of the natural disaster impacts.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.2
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• pp.161-172
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• 2014

Hydrogen, which can be produced from abundant and widely distributed renewable energy resources, seems to be a promising candidate for solving the concerns for improving energy security, urban air pollution, and reducing greenhouse gas emissions. The two primary motivating factors for hydrogen economy are fossil fuel supply limitations and concerns about global warming. But the safety issues associated with hydrogen economy need to be investigated and fully understood before being considered as a future energy source. Limited operating experience with hydrogen energy systems in consumer environments is recognised as a significant barrier to the implementation of hydrogen economy. To prevent unnecessary restrictions on emerging codes, standards and local regulations, safety policies based on real hazards should be developed. This article studies briefly the direct impact-distances from hazard events such as hydrogen release and jet fire, and damage levels from hydrogen gas explosion in a confined space. Based on the direct impact-distances indicated in the accident scenarios and consumer environments in Korea, the safety policies, which are related to hydrogen filling station, hydrogen fuel cell car, portable fuel cell, domestic fuel cells, and hydrogen town, are suggested to implement hydrogen economy. To apply the safety policies and overcome the disadvantages of prescriptive risk management, which is setting guidance in great detail to management well known risk but is not covering unidentified risk, hybrid risk management model is also proposed.