• Journal of Information Technology Services
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• v.15 no.3
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• pp.173-193
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• 2016

Start-ups do not have enough resources such as financial capital and established customer base. Knowledge base of start-up team members is the crucial and unrivaled resource. This study tries to explicate the knowledge sharing process occurring in this knowledge base of start-up teams. Adopting the knowledge process view, detail process of knowledge sharing process model is constructed consisting of knowledge sharing speed, quality and quantity in a form of nomological net and empirically tested. In addition, preceding antecedents and consequential outcomes of this knowledge sharing is also posited as part of the research model : knowledge state of the team leading to team creativity and agility via the explicated knowledge sharing process model. Also, as this knowledge based view are triggered by the advance of IT in general, IT support is conceptualized as an antecedent and measures are operationalized. 230 data points were collected from start-up teams. Via data analysis using PLS, theoretical relationships from knowledge state, IT support, knowledge sharing process and knowledge consequences are found to be empirically supported except a few not supported. Most of all, team agility and team creativity are theoretically supported and empirically validated as critical outcome variables beyond performance measures. Though agility and creativity has been discussed as critical construct in start-up teams, it has not be much validated empirically. Also, interestingly, IT support are found to be significantly impacting the knowledge sharing process as expected. Academic contributions and implications for practice are discussed at the end with limitations and further research.

• Journal of Korean Society of Disaster and Security
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• v.5 no.1
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• pp.13-19
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• 2012

This paper introduces platform of platform (POP) for global network on climate adaptation change and disaster risk reduction (CCA/DRR). The POP consists of disaster prevention technology e-market platform, e-learning platform, information sharing platform, and monitoring platform for AMCDRR action plan. The POP is developing based on Korean e-Government standard framework and supports Web and mobile service. Additionally the POP uses special product and technology to search and classify data about CCA/DRR.

• ETRI Journal
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• v.34 no.2
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• pp.272-275
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• 2012

This letter studies the problem of exploiting multichannel diversity in a spectrum sharing system, where the secondary user (SU) sequentially explores channel state information on the licensed channels with time consumption. To maximize the expected achievable throughput for the SU, we formulate this problem as an optimal stopping problem, whose objective is to choose the right channel to stop exploration based on the observed signal-to-noise ratio sequence. Moreover, we propose a myopic but optimal rule, called one-stage look-ahead rule, to solve the stopping problem.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4552-4567
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• 2014

A (n,t,n) secret sharing scheme is to share a secret among n group members, where each member also plays a role of a dealer,and any t shares can be used to recover the secret. In this paper, we propose a strong (k,t,n) verifiable multi-secret sharing scheme, where any k out of n participants operate as dealers. The scheme realizes both threshold structure and adversary structure simultaneously, and removes a trusted third party. The secret reconstruction phase is performed using an additive homomorphism for decreasing the storage cost. Meanwhile, the scheme achieves the pre-verification property in the sense that any participant doesn't need to reveal any information about real master shares in the verification phase. We compare our proposal with the previous (n,t,n) secret sharing schemes from the perspectives of what kinds of access structures they achieve, what kinds of functionalities they support and whether heavy storage cost for secret share is required. Then it shows that our scheme takes the following advantages: (a) realizing the adversary structure, (b) allowing any k out of n participants to operate as dealers, (c) small sized secret share. Moreover, our proposed scheme is a favorable candidate to be used in many applications, such as secure multi-party computation and privacy preserving data mining, etc.

• STI Policy Review
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• v.7 no.2
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• pp.60-84
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• 2016

What impact does the sharing economy have on existing businesses? This paper empirically examines how Uber transformed the taxi industry in New York City. Using a regression model controlling various potential influencing factors, we find no direct evidence that daily trips or revenue per taxi driver decreased since Uber entered the taxi industry. However, a closer investigation into other dimensions of taxi trips reveals that taxi drivers were forced to change their way of doing businesses to retain existing daily trips and revenue. Since Uber crowded out yellow taxis from the central area of Manhattan, yellow taxis responded by serving customers outside of the Manhattan borough. From enlarging their geographical coverage and serving customers that were previously ignored, yellow taxis were able to retain their previous level of taxi trips and market share. We also find that yellow taxis responded by improving their service quality to better serve customers' needs. Our result suggests that incumbents actively responded to Uber's entry and provided substantial benefit to consumers. Combined with the incumbent's response, the sharing economy transformed the existing market in a welfare-enhancing way. This paper provides managerial and policy implication on how incumbents affected by the disruptions of the sharing economy should respond. Even though it might be yet premature to examine the impact of Uber, results suggest that incumbents have effectively defended against Uber's entry so far. We conclude that the sharing economy and the existing economy can create positive value in our society through well-intentioned competition, complementing each other's weaknesses and strengths.

• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.149-168
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• 2015

In cognitive radio networks (CRNs), hybrid overlay and underlay sharing transmission mode is an effective technique for improving the efficiency of radio spectrum. Unlike existing works in the literature, where only one secondary user (SU) uses overlay and underlay modes, the different transmission modes should be allocated to different SUs, according to their different quality of services (QoS), to achieve the maximal efficiency of radio spectrum. However, hybrid sharing mode allocation for heterogeneous services is still a challenge in CRNs. In this paper, we propose a new resource allocation method for hybrid sharing transmission mode of overlay and underlay (HySOU), to achieve more potential resources for SUs to access the spectrum without interfering with the primary users. We formulate the HySOU resource allocation as a mixed-integer programming problem to optimize the total system throughput, satisfying heterogeneous QoS. To decrease the algorithm complexity, we divide the problem into two sub-problems: subchannel allocation and power allocation. Cutset is used to achieve the optimal subchannel allocation, and the optimal power allocation is obtained by Lagrangian dual function decomposition and subgradient algorithm. Simulation results show that the proposed algorithm further improves spectrum utilization with a simultaneous fairness guarantee, and the achieved HySOU diversity gain is a satisfactory improvement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.10
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• pp.5144-5160
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• 2019

Secret sharing is an effective way of protecting secret messages. However, the traditional secret sharing schemes are considered meaningless due to malicious people attention which might raise risks. To overcome the weakness, this paper presents an effective secret sharing scheme with the functionality of cheater identification, based on meaningful QR code. The secret message will be split and concealed in the padding region of cover QR codes with the assistance of Latin square and it can be completely restored when all the involved participants cooperate. The concealing strategy exploits the characteristic of Reed-Solomon (RS) code to ensure the strong robustness of generated QR code pseudo-shares. The meaningful QR code pseudo-shares help to reduce the curious of unrelated persons. Some experiments were done to evaluate the performance of proposed scheme. The results showed that the proposed scheme is feasible, efficient and secure compared to the other existing schemes. It also achieves a higher secret payload and maintains stronger robustness.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2315-2326
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• 2016

This paper discusses the elimination of DC voltage deviation and the enhancement of load current sharing accuracy in multi-terminal high voltage direct current (MT-HVDC) systems. In order to minimize the power line losses in different parallel network topologies and to insure the stable operation of systems, a decentralized control method based on a modified droop control is presented in this paper. Averaging the DC output voltage and averaging the output current of two neighboring converters are employed to reduce the congestion of the communication network in a control system, and the decentralized control method is implemented. By minimizing the power loss of the cable, the optimal load current sharing proportion is derived in order to achieve rational current sharing among different converters. The validity of the proposed method using a low bandwidth communication (LBC) network for different topologies is verified. The influence of the parameters of the power cable on the control system stability is analyzed in detail. Finally, transient response simulations and experiments are performed to demonstrate the feasibility of the proposed control strategy for a MT-HVDC system.

• Journal of Contemporary Eastern Asia
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• v.20 no.2
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• pp.40-62
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• 2021

Are intentions important in deciding the outcome of an action such as sharing misinformation among social media users during the pandemic? What is their role and how far they are important for the very act of fake sharing news? The social media users' actions on the social platform are determined by what they plan to do themselves; however, their motivation has an immense role to play in the dissemination of fake news on social media. The study proposes a conceptual model for understanding how select factors affect fake news sharing motivation and intentions of social media users. The study scrutinizes the relationship between content and context, fear of missing out (FoMO), news verification and news sharing gratification on the motivation and intention of social media users of networked Asian society. Empirical Data were drawn from social media users (N = 243) from India, using an online questionnaire based on prior studies and structural equation modeling (SEM) approach was used to analyze the data collected. Results indicate that news content, news verification, and news sharing gratification have a direct and positive relationship with sharing motivation. On the other hand, news context and content, FoMO and news sharing gratification have a positive significant relationship with sharing intention. Likewise, it was discovered that news verification will decrease sharing intention of the social media users. However, news context, that is the pandemic in the case of the present study and FoMO were not identified as determinant variables for sharing motivation among social media users. The research limitations and further scope were discussed.