• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.252-263
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• 2017

The study empirically explored factors influencing photo sharing behavior on Instagram based on the uses and gratification theory. An online survey was conducted 356 respondents those who have used Instagram and have shared photos within the last three months. Frequency analysis, descriptive statistics, confirmatory factor analysis, and structural model analysis were conducted using SPSS 19.0 and AMOS 21.0. The results of this study are as follows: first, communication has the greatest effect on photo-sharing behavior; second, entertainment has a positive effect on photo-sharing behavior; third, self-expression has a positive effect on photo-sharing behavior; fourth, service users' trust has a positive effect on photo-sharing behavior. This study adds to the current literature and contributes to understanding consumers' photo-sharing behavior.

• Journal of KIBIM
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• v.6 no.1
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• pp.25-32
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• 2016

In BIM environments for infrastructures, civil structures such as road, bridge and tunnel etc., created into 3D objects, integrated with their properties, securing BIM design productivity is very critical during 3D modeling. To solve this issue, configuring BIM libraries so that the users can utilize prefabricating in advance 3D objects that have been applying repeatedly during BIM design is essential so much. Current BIM libraries have made focused on Ready-Made for architectural facilities. However, establishing environment for delivering BIM library for civil facilities is very sparse. Accordingly, this study developed a web-based sharing system for delivering BIM library contents based on standardized drawing for civil area. To do this, we have analyzed core features and operation system of BIM library sharing system in domestic and overseas. Besides, functional requirements that are necessary for developing BIM library sharing system was derived, and through operation scenario configuration, the web-based system was developed according to the detailed mechanism. It is expected that this system can enhance BIM design productivity during library based modeling, and can be utilized as construction supporting tools that can help construction managers to make a design change.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.5
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• pp.549-556
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• 2014

This paper proposes a highly power-efficient single-inductor multiple-outputs (SIMO) DC-DC converter with a gate charge sharing method in which gate charges of output switches are shared to improve the power efficiency and to reduce the switching power loss. The proposed converter was fabricated by using a $0.18{\mu}m$ CMOS process technology with high voltage devices of 5 V. The input voltage range of the converter is from 2.8 V to 4.2 V, which is based on a single cell lithium-ion battery, and the output voltages are 1.0 V, 1.2 V, 1.8 V, 2.5 V, and 3.3 V. Using the proposed gate charge sharing method, the maximum power efficiency is measured to be 87.2% at the total output current of 450 mA. The measured power efficiency improved by 2.1% compared with that of the SIMO DC-DC converter without the proposed gate charge sharing method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.111-116
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• 2015

This article considers a model of cooperative spectrum sharing between primary and secondary systems in which transmission occurs in two phases. In this scheme, we introduce that a single secondary transmitter, ST, employs a quadrature-phase-based signal to present the secondary message, while the primary message is presented by an in-phase-based signal. This allows simultaneous spectrum sharing without mutual interference. Therefore, an interference constraint is not necessary to protect primary operating performance from being degraded by the secondary user operations. Theoretical analysis and Simulations are then provided to confirm the superiority of the proposed scheme over the the current conventional methods.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.101-108
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• 2015

Location-sharing based service (LSBS) refers to a service that users share their location information with other users with whom friendship. At this time, the location information is shared through service provider, and then their position information is exposed to the service provider. The exposure of this personal position information to the service provider has raised a privacy problem, and thus privacy preserving mechanisms have been proposed to protect them. In this paper, we examine the types and features of the proposed location-sharing based services so far, and survey the research trend of privacy preserving mechanisms for them. Through the analysis on existing privacy preserving mechanisms, we present design factors for a privacy preserving mechanism for the current LSBS services, and suggest future work.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.3
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• pp.1028-1046
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• 2022

Genome-wide association studies (GWAS) aim to find the significant genetic variants for common complex disease. However, genotype data has privacy information such as disease status and identity, which make data sharing and research difficult. Differential privacy is widely used in the privacy protection of data sharing. The current differential privacy approach in GWAS pays no attention to raw data but to statistical data, and doesn't achieve equilibrium between utility and privacy, so that data sharing is hindered and it hampers the development of genomics. To share data more securely, we propose a differential privacy preserving approach of data sharing for GWAS, and achieve the equilibrium between privacy and data utility. Firstly, a reasonable disturbance interval for the genotype is calculated based on the expected utility. Secondly, based on the interval, we get the Nash equilibrium point between utility and privacy. Finally, based on the equilibrium point, the original genotype matrix is perturbed with differential privacy, and the corresponding random genotype matrix is obtained. We theoretically and experimentally show that the method satisfies expected privacy protection and utility. This method provides engineering guidance for protecting GWAS data privacy.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.272-275
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• 2003

Quench and recovery process of high-temperature-superconductor(HTS) film deposited on the sapphire substrate is studied numerically. The quench is developed by fault current and the superconductivity is recovered by convection of heat into coolant. After the fault current, the HTS film experiences the quench state, current sharing state, and finally recovers the superconductivity. Numerical results of this study are compared to the previous experimental results, and shows that this numerical work can explain the mechanism of quench/recovery characteristics of HTS film.

• The Journal of Fisheries Business Administration
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• v.46 no.2
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• pp.43-57
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• 2015

The study aims to identify the current status of aquaculture information in Korea and suggests policy directions for its integrated management. Firstly, the study focuses on the identification of the current status of aquaculture information by reviewing how aquaculture information is managed. Secondly, this study identifies problems such as lacks in necessary aquaculture information, inefficiency caused by dispersion and overlapping of information, absence of integrated management system and insufficient sharing of information. After identifying the current status of aquaculture information and its problems, the study suggests three basic directions to systematically integrate and manage the information such as establishment of infrastructure for promoting the integrated management of aquaculture information, generation and systematic management of useful aquaculture information and enhancement of user convenience. Finally, the study suggests detailed strategies such as establishment of a foundation to facilitate integrated management of aquaculture information, organization of organic network, sharing of more information, creation of necessary information through demand survey, creation of systematic management system, provision of a customized total service, and increase in education and PR activities on information use.

• KIEE International Transactions on Power Engineering
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• v.3A no.4
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• pp.222-230
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• 2003

This paper presents reference designs for vapor-cooled HTS/Copper leads rated at 25 kA and 40 kA and that satisfy a protection criterion. Each HTS section is cooled by the effluent helium vapor boiling from a 4.2-K bath. Each HTS section is based on a design concept in which a short portion of its warm end (77.3 K) operates in the current-sharing mode; such operation results in a considerable saving for HTS materials required in the HTS section. Two designs of "fully superconducting" vapor-cooled HTS sections, one rated at 25 kA and the other at 40 kA are also presented as comparison bases for the new HTS sections. Each warm end of HTS sections is coupled to an optimal vapor-cooled copper lead rated at the same current as that for the HTS section. The extra coolant required at 77.3 K at the coupling station, an optimal length of the copper section will be shorter than that optimized for helium-vapor cooling between 4.2 K and room temperature.mperature.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1296-1308
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• 2014

This paper presents a new zero voltage switching (ZVS) converter for medium power and high input voltage applications. Three three-level pulse-width modulation (PWM) circuits with the same power switches are adopted to clamp the voltage stress of MOSFETs at $V_{in}/2$ and to achieve load current sharing. Thus, the current stresses and power ratings of transformers and power semiconductors at the secondary side are reduced. The resonant inductance and resonant capacitance are resonant at the transition interval such that active switches are turned on at ZVS within a wide range of input voltage and load condition. The series-connected transformers are adopted in each three-level circuit. Each transformer can work as an inductor to smooth the output current or a transformer to achieve the electric isolation and power transfer. Thus, no output inductor is needed at the secondary side. Three center-tapped rectifiers connected in parallel are used at the secondary side to achieve load current sharing. Compared with the conventional parallel three-level converters, the proposed converter has less switch counts. Finally, experiments based on a 1.44kW prototype are provided to verify the operation principle of proposed converter.