• Journal of Information Technology Services
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• v.12 no.2
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• pp.119-129
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• 2013

The degree to which people share knowledge has major impacts on the effectiveness of virtual community of practice (VCoP). As an extension to the previous study which investigated the effect of individual cooperative types (cooperator, reciprocator, and free rider) on knowledge sharing, it is investigated how much increase in the degree of cooperation will enhance knowledge sharing when there are more knowledge contributors and strong ties exist across the community. Simulation method is adopted to measure the effect of the cooperative type and tie strength on knowledge sharing. The results reveal that the tie strength positively affects knowledge contribution in VCoP and strongly tied VCoP generates equivalent level of knowledge contribution as that of weakly-tied VCoP with 5% more contributors.

• Journal of the Korea Society of Computer and Information
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• v.24 no.6
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• pp.211-216
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• 2019

Knowledge sharing is safe to say that we have already embarked on knowledge-based global economy where knowledge is a decisive factor in global competition for corporations. So in the age of knowledge-based management, it is how we use knowledge that decides success or failure for corporations and the competitiveness of their countries at large as well. We did this research with the help of those who were working in ICT industry including manufacturing, tourism, and others. In this research, we looked into how project participants, organizational characteristic, and relational characteristic affect knowledge sharing and utilization, and what are the factors that have positive effects on corporate success. And all the factors presented in the research are found to have positive effects on the knowledge sharing and utilization. The factors appeared to have positive effects starting with project at first and then on corporate success at large.

• International Journal of Computer Science & Network Security
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• v.23 no.2
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• pp.89-95
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• 2023

Cloud computing today provides huge computational resources, storage capacity, and many kinds of data services. Data sharing in the cloud is the practice of exchanging files between various users via cloud technology. The main difficulty with file sharing in the public cloud is maintaining privacy and integrity through data encryption. To address this issue, this paper proposes an Enhanced RSA encryption schema (ERSA) for data sharing in the public cloud that protects privacy and strengthens data integrity. The data owners store their files in the cloud after encrypting the data using the ERSA which combines the RSA algorithm, XOR operation, and SHA-512. This approach can preserve the confidentiality and integrity of a file in any cloud system while data owners are authorized with their unique identities for data access. Furthermore, analysis and experimental results are presented to verify the efficiency and security of the proposed schema.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.965-968
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• 2013

In this paper presented car sharing service using eco driving components. The car sharing service is composed of a web service and a smartphone application. The proposed service claims a newly time and fuel consumption based service charge. In order to get the fuel consumption, we used a MAF (Mass Air Flow) of OBD-II data. The application connects the smartphone to the car's OBD-II port through Bluetooth.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3731-3750
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• 2014

This paper considers a wideband cognitive radio network (WCRN) which can simultaneously sense multiple narrowband channels and thus aggregate the detected available channels for transmission and studies the ergodic throughput of the WCRN that operated under: the wideband sensing-based spectrum sharing (WSSS) scheme and the wideband opportunistic spectrum access (WOSA) scheme. In our analysis, besides the average interference power constraint at PU, the average transmit power constraint of SU is also considered for the two schemes and a novel cognitive radio sensing frame that allows data transmission and spectrum sensing at the same time is utilized, and then the maximization throughput problem is solved by developing a gradient projection method. Finally, numerical simulations are presented to verify the performance of the two proposed schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.430-432
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• 2022

With the recent increase in interest in the open science movement in science and technology fields such as open access, open data, and open source, the movement to share and utilize publicly funded research products is materializing and revitalizing. In line with this trend, many efforts are being made to establish and revitalize a system for sharing and utilizing research data, which is a key resource for research in Korea. These efforts are mainly focused on collecting research data by field and institution, and linking it with DataON, a national research data platform, to search and utilize it. However, developed countries are building a system that can share and utilize not only such research data but also various types of R&D-related computing resources such as IaaS, PaaS, SaaS, and MLaaS. EOSC (European Open Science Cloud), ARDC (Australian Research Data Commons), and CSTCloud (China S&T Cloud) are representative examples. In Korea, the Korea Research Data Commons (KRDC) is designed and a core framework is being developed to facilitate the sharing of these computing resources. In this study, the necessity, concept, composition, and future plans of KRDC are introduced.

• Journal of Communications and Networks
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• v.16 no.3
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• pp.301-304
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• 2014

This paper proposes accurate interference probability and bit error rate formulas for cognitive relay networks with underlay spectrum sharing and channel estimation error (CEE). Numerous results reveal that the CEE not only degrades the performance of secondary systems (SSs) but also increases interference power caused by SSs to primary systems (PSs), eventually unfavorable to both systems. A solution to further protect PSs from this effect through reducing the power of secondary transmitters is investigated and analyzed.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.140-145
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• 2014

In this paper, we propose an anti-interference cooperative spectrum sharing strategy for cognitive system, in which a secondary system can operate on the same spectrum of a primary system. Specifically, the primary system leases a fraction of its transmission time to the secondary system in exchange for cooperation to achieve the target rate. To gain access to the spectrum of the primary system, the secondary system needs to allocate a fraction of bandwidth to help forward the primary signal. As a reward, the secondary system can use the remaining bandwidth to transmit its own signal. The secondary system uses different bandwidth to transmit the primary and its own signal. Thus, there will be no interference felt at primary and secondary systems. We study the joint optimization of time and bandwidth allocation such that the transmission rate of the secondary system is maximized, while guaranteeing the primary system, as a higher priority, to achieve its target transmission rate. Numerical results show that the secondary system can gain significant improvement with the proposed strategy.

• Journal of Power Electronics
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• v.19 no.4
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• pp.934-943
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• 2019

A current balance problem exists in multi-phase LLC converters due to the resonant parameter tolerance. This paper presents a current balancing method for interleaved three-phase half bridge LLC converters. This method regulates the phase shift angle of the driving signals between the three phases based on a converter with a floating Y-connection. The floating midpoint voltage has different influences on each phase current and makes the three-phase current balance performance better than midpoint non-floating systems. Phase shift control between modules can further regulate the midpoint voltage. Then three phase current sharing is realized without adding extra components. The current distributions in a midpoint non-floating system and a midpoint floating system are compared. Then the principle and implementation of the proposed control strategy are analyzed in detail. A 3kW prototype is built to verify the validity and feasibility of the proposed method.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• v.55 no.6
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• pp.538-545
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• 2018

It is necessary to develop systematic mine reclamation technology according to mid- and long-term road maps to effectively promote mine reclamation projects. Evaluating the main achievements of the mine reclamation technology according to the first and second-stage roadmaps revealed the necessity of sharing the R&D achievements. In this study, by reviewing the key issues of the third-stage roadmap and considering the major technical needs of in-and-out customers, the strategic development direction of sustainable mine reclamation technology through expanded sharing of R&D achievement was examined.