• Journal of Communications and Networks
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• 제15권2호
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• pp.228-239
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• 2013

Peer-to-peer (P2P) systems have proved the most effective and popular file sharing applications in recent years. Previous studies mainly focused on equal service and differentiated service strategies when peers have no initial data before their downloads. For an upload-constrained P2P file sharing system, we model both the equal service process and the differentiated service process when the initial data distribution of peers satisfies some special conditions. Moreover, we show how to minimize the time required to distribute the file to any number of peers. The proposed fluid-based models can reveal the intrinsic relations among the initial data amount, the peer set size, and the minimum last finish time. The closed-form expressions derived from the extended models can closely approximate chunk-based models and systems, especially for relatively large files. As an application of the extended models, we show how to provide differentiated service efficiently to multiple peer sets. Since no limits are imposed on the upload bandwidth of peers or the size of each peer set, we believe that our analytic process and the results achieved can provide not only fundamental insights into bandwidth allocation and data scheduling but also a helpful reference for both improving system performance and building an effective incentive mechanism for P2P file sharing systems.

• Journal of Power Electronics
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• 제10권6호
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• pp.673-679
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• 2010

Input-series-output-parallel (ISOP) connected DC-DC converters enable low voltage rating switches to be used in high voltage input applications. In this paper, a DSP is adopted to generate digital phase-shifted PWM signals and to fulfill the closed-loop control function for ISOP connected two full-bridge DC-DC converters. Moreover, a stable output current sharing control strategy is proposed for the system, with which equal sharing of the input voltage and the load current can be achieved without any input voltage control loops. Based on small signal analysis with the state space average method, a loop gain design with the proposed scheme is made. Compared with the conventional IVS scheme, the proposed strategy leads to simplification of the output voltage regulator design and better static and dynamic responses. The effectiveness of the proposed control strategy is verified by the simulation and experimental results of an ISOP system made up of two full-bridge DC-DC converters.

• International Journal of Quality Innovation
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• 제8권2호
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• pp.69-87
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• 2007

High-tech industries in Taiwan exist in an environment with diverse product requirements and intense cost reduction and information integration stress. They must develop new operational directions to increase industry competitiveness. Therefore, Taiwan's high-tech industries must continue R&D and creativity, establish knowledge sharing mechanisms and improve new product development (NPD) performance. This research analyzed and explored the influences of knowledge management (KM) and knowledge sharing mechanisms introduced by Taiwan's high-tech industries on new product development performance. The relationship between knowledge management capabilities and NPD performance is studied. This research considers the intervening industry and corporate position variables. Taiwan's high-tech industries have gradually entered the era of IT region integration and application with competitive advantage creation based upon core techniques. The in-depth study of knowledge management and knowledge sharing introduced by the high-tech industry revealed double meanings in academic and practical applications. The research results showed the following: (1) the stronger the knowledge management capabilities of Taiwan's high-tech industries, the more significant the NPD performance. (2) The better the knowledge sharing mechanism in Taiwan's high-tech industries, the more significant the NPD performance. (3) Corporate scale is not necessarily the critical factor in NPD success and the influence of corporate scale on NPD performance did not show significant differences. (4) The stronger the degree of leading corporate techniques, the more significant the NPD performance.

• Journal of Information Technology Applications and Management
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• 제22권2호
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• pp.43-70
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• 2015

Concerns have been growing about whether domestic internet protocol television (IPTV) can establish a solid foothold in the pay TV market, largely because of the lack of IPTV-only content and service differentiation. It has been difficult for IPTV providers to attract valuable PPs (program providers) to strengthen their positions, and IPTV providers have invested much money into procuring content. To survive this difficult situation, IPTV providers need to reappraise their profit sharing methods and content distribution structure to facilitate the expansion of their subscriber base. This can be done by attracting valuable PPs to IPTV providers and securing extra revenue by distributing more content for their PP partners. The IPTV industry has a different structure and value chain from the digital cable industry. Moreover, profit sharing schemes among participants in the IPTV industry are complicated. Thus it is essential to analyze the criteria for profit sharing, the selection of attributes in profit sharing, and their cause-effect relationship in developing fair pricing for broadcast content in the IPTV industry. This study introduces the attributes that need to be considered for the pricing of content and profit sharing among IPTV providers and PPs. In addition, this study uses system dynamics to analyze the relationship among those attributes along with additional associated factors for the pricing of content.

• 한국생산제조학회지
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• 제25권2호
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• pp.97-104
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• 2016

In this study, the qualitative effects of the positional error of carrier pin holes on the planet load sharing characteristics of the three-point suspension gearbox of wind turbines were investigated experimentally. A 35-kW gearbox comprising two planetary gear stages and a parallel gear stage and size one-fourth of that of a 2-MW three-point suspension gearbox was used as the test gearbox. The strain gauges attached to the ring gear teeth of the input planetary gear stage were used for the purpose of this study. The applied loading conditions were 50%, 75%, and 100% of the rated torque, and the mesh load factor was used as the load sharing index. The experimental results indicated that both the magnitude and direction of the positional error of pin holes had a significant effect on the planet load sharing characteristics of the three-point suspension gearbox. In addition, an increase in the applied torque results in uniform load sharing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2865-2878
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• 2021

As a current popular technology, the blockchain has a serious issue: the private key cannot be retrieved due to force majeure. Since the outcome of the blockchain-based Bitcoin, there have been many occurrences of the users who lost or forgot their private keys and could not retrieve their token wallets, and it may cause the permanent loss of their corresponding blockchain accounts, resulting in irreparable losses for the users. We propose a recoverable private key scheme for consortium blockchain based on the verifiable secret sharing which can enable the user's private key in the consortium blockchain to be securely recovered through a verifiable secret sharing method. In our secret sharing scheme, users use the biometric keys to encrypt shares, and the preset committer peers in the consortium blockchain act as the participants to store the users' private key shares. Due to the particularity of the biometric key, only the user can complete the correct secret recovery. Our comparisons with the existing mnemonic systems or the multi-signature schemes have shown that our scheme can allow users to recover their private keys without storing the passwords accurately. Hence, our scheme can improve the account security and recoverability of the data-sharing systems across physical and virtual platforms that use blockchain technology.

• International Journal of Knowledge Content Development & Technology
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• 제10권4호
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• pp.65-82
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• 2020

This study examined information sharing and evaluation as determinants of the spread of fake news among Nigerian youths on social media using experience from COVID-19 pandemic. A descriptive survey design was adopted for the study and a Web-based questionnaire (Google Forms) was used to collect data for the study. The total responses of 278 were collected from the participants, which represents the unit of analysis. The finding of the study revealed that most Nigerian youths used Facebook, Twitter, WhatsApp and Instagram to share information on COVID-19. However, only a few Nigerians used Linkedln and other types of social media to share information on COVID-19. It was also found that building a relationship with social media communities, enjoyment and risk taking, and political inclination influence the sharing behavior of Nigerian youths during the COVID-19 pandemic. Results show that social media handle/page found sharing of fake news on COVID-19 especially on the treatment, vaccines numbers of cases and symptoms. The study concludes that there is a positive relationship between information evaluation and the spreading of fake news on COVID-19 among Nigerians. Information sharing and evaluation should be done with the utmost level of objectivity and sincerity.

• Design & Manufacturing
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• 제9권2호
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• pp.6-9
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• 2015

The objective of manufacturing knowledge sharing platform is to convert the production experience like a worker's know-how into quantitative values, to construct database of the process technologies and to share the technologies systematically via web portal service. In addition, the knowledge sharing platform contains the total production processes of automobile and mobile products such as information of experts, facilities, and cutting-edge R&D outputs. Automobile, telecommunication mobile, and semiconductors account for a large amount of Korea's export industry rate. These industries need production technology which is a result of converting worker's know-how and R&D. Manufacturing knowledge portal aims to enable transforming production experience such as worker's know-how into standardized form for constructing database and sharing technologies systematically. Manufacturing knowledge portal can contribute to small and mid-sized manufacturing companies with further improvements.

• 전자통신동향분석
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• 제37권4호
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• pp.11-18
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• 2022

Sharing vehicle data among the companies within a car ecosystem can improve driving experience, increase driver comfort, contribute to social goals such as improving road safety and lowering fuel consumption. Furthermore, by participating in the ecosystem, companies can secure long-term and sustainable new revenue-generating opportunities. In this paper, we will examine the bottleneck and success factors of data sharing, as well as the technological solutions that urgently require development for car data sharing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.5803-5819
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• 2017

In this paper, we proposed a contract theory based cooperative spectrum sharing scheme with joint power and bandwidth optimization under asymmetric information, where the primary user (PU) does not know the secondary users' (SUs) private information. To improve performance, PU needs to provide incentives to stimulate nearby SUs to help forward its signal. By using contract theory, PU and SUs' negotiations are modeled as a labor market. PU and SUs act as the employer and employees, respectively. Specifically, SUs provide labor (i.e. the relay power, which can be used for forwarding PU's signal) in exchange for the reward (i.e. the spectrum access bandwidth which can be used for transmitting their own signals). PU needs to overcome a challenge how to balance the relationship between contributions and incentives for the SUs. We study the optimal contract design which consists of relay power and spectrum access bandwidth allocation. We show that the most efficient SUs will be hired by the PU to attend the cooperative communication. PU can achieve the same maximum utility as in the symmetric information scenario. Simulation results confirm that the utility of PU is significantly enhanced with our proposed cooperative spectrum sharing scheme.