• 한국군사과학기술학회지
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• 제15권4호
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• pp.442-449
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• 2012

Cognitive Radio(CR) is the technology that allocates the frequency by using dynamic spectrum access. We proposed a model to calculate the optimal level of the cognitive radiotelegraph, where secondary users opportunistically share the spectrum with primary users through the spectrum sensing. When secondary user with cognitive radio detects the arrival of a primary user in its current channel, the secondary user moves to the idle channel or be placed in the virtual queue. We assume that the primary users have finite buffers and the population of secondary users is finite. Using a two-dimensional Makov model with preemptive priority queueing, we could derive the blocking and waiting probability as well as the optimal level of cognitive radiotelegraph under a various range of parameter circumstances.

• 한국항공운항학회지
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• 제6권1호
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• pp.125-145
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• 1998

The term "Privatization" has a different meaning in different contexts and cultures. In this paper, the term "Privatization" in the context of airports is defined as the movement of an entity from the government sector to the private sector. This is the definition that is commonly employed in the U.S. Airport revenue can he divided into two sub-categories of aeronautical revenue and non-aeronautical revenue. At many of the major international airports, however, non-aeronautical revenue has been growing faster than the aeronautical revenue, contributing an increasingly larger share of the total revenue. And the best way to enhance simultaneously the airport operations. With the remarkable growth in the air traffic volume of pssengers and cargo. more and more mega-international airports have been built or are under construction. As the air transport demand is expected to increase at an even greater rate in the 21st century, new types of airports which will be free of current major problems. such as airport congestion and flight delays are badly needed.

• 한국IT서비스학회지
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• 제9권2호
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• pp.193-203
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• 2010

Service-Oriented Architecture (SOA) is a new trend for the design of application architecture to enhance the degree of share and reuse with the concept of service. It comes from the current situation where the business environments are changing rapidly and therefore competitions are getting bitter. To cope with such business challenges, business (and/or applications) architecture needs considerably flexibility and reusability, and that's why SOA is accepted as one of the most effective framework for the business applications in these days. In this paper we propose an analysis and design methodology for the applications of SOA. To implement the proposed methodology, the service ontology needs to be defined first, and the tasks such as service profiling, workflow design and service orchestration need to be followed. To validate the expected effects on flexibility and reusability, the proposed methodology was compared with CBD (Component Based Development).

• 한국유통학회지:유통연구
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• 제1권1호
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• pp.9-40
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• 1996

This year marks the full liberalization(i.e., opening up) of the Korean distribution market to foreign firms. Therefore, we are likely to see much activity by foreign retailers who will be entering the Korean market and indigenous retailers trying to depend their current market positions. The liberalization of Korean distribution market will undoubtedly lead to some erosion of market share of indigenous retailers, but the benefits of rationalization of distribution, stable consumer prices, strengthened competitiveness of indigenous retailers far outweigh the costs. With liberalization, we are likely to see increased growth of "New Modes of Retailing(NMR)." In this paper, I describe the distinguishing characteristics of NMR as economies of scale, self service, large physical facilities, low-to-medium price, and systemization. I also describe the similarities and differences between the various types of NMR. Finally, I describe the fit between the various forms of NMR and the Korean consumer environment.vironment.

• Journal of Information Processing Systems
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• 제6권1호
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• pp.43-52
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• 2010

In the secure communication areas, three-party authenticated key exchange protocol is an important cryptographic technique. In this protocol, two clients will share a human-memorable password with a trusted server, in which two users can generate a secure session key. On the other hand the protocol should resist all types of password guessing attacks. Recently, STPKE' protocol has been proposed by Kim and Choi. An undetectable online password guessing attack on STPKE' protocol is presented in the current study. An alternative protocol to overcome undetectable online password guessing attacks is proposed. The results show that the proposed protocol can resist undetectable online password guessing attacks. Additionally, it achieves the same security level with reduced random numbers and without XOR operations. The computational efficiency is improved by $\approx$ 30% for problems of size $\approx$ 2048 bits. The proposed protocol is achieving better performance efficiency and withstands password guessing attacks. The results show that the proposed protocol is secure, efficient and practical.

• Advances in Energy Research
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• 제3권2호
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• pp.97-115
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• 2015

Energy holds key to economic growth and prosperity of India. Currently, India has very high-energy import dependence, especially in the case of crude oil (80%) and natural gas (40%). Even coal import has been increasing over the years. Considering India's population growth, emphasis on manufacturing, production, and service industry, energy consumption is bound to increase. More fossil energy consumption means greater dependence on energy import leading to widening trade deficit and current account deficit. Therefore, exploitation of indigenous renewable energy production is necessary. The paper reviews the progress and growth of renewable energy production, distribution, and consumption in India. The paper highlights some of the enablers of renewable energy in India. The authors discuss the opportunities and challenges of increasing share of renewable energy to reduce energy import and address issues of energy security in India. The findings suggest that India is ready for a quantum leap in renewable production by 2022.

• Journal of Information Science Theory and Practice
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• 제9권3호
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• pp.1-13
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• 2021

In the current smart device-based information environment, information utilization is closely related to social capital. Additionally, the smart divide that occurs owing to the differences in use of smart devices has a significant influence on social capital. In this respect, this research empirically analyzed how the smart divide affects social capital construction. The study found that the level of and proficiency in using smart devices and diversity of the information formats used through smart devices affect social capital construction. Further, people who fully utilize smart devices can enhance their participation in social activities, social networks, and reciprocal activities, leading people to construct social capital in a wider range. Contrarily, those who are unable to use smart devices adequately may be disadvantaged in terms of the opportunity to construct social capital and share public interests. Thus, to maximize the intrinsic value of social capital, it is necessary to consider the factors of the smart divide as a complicated and multi-faceted digital divide and the ways to utilize social capital as a driving force for integrating society, and not as a mechanism for dividing members of society.

• ETRI Journal
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• 제41권2호
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• pp.224-234
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• 2019

This paper proposes a new spectrum forecasting (SF) model to estimate the spectrum demands for future mobile broadband (MBB) services. The model requires five main input metrics, that is, the current available spectrum, site number growth, mobile data traffic growth, average network utilization, and spectrum efficiency growth. Using the proposed SF model, the future MBB spectrum demand for Malaysia in 2020 is forecasted based on the input market data of four major mobile telecommunication operators represented by A-D, which account for approximately 95% of the local mobile market share. Statistical data to generate the five input metrics were obtained from prominent agencies, such as the Malaysian Communications and Multimedia Commission, OpenSignal, Analysys Mason, GSMA, and Huawei. Our forecasting results indicate that by 2020, Malaysia would require approximately 307 MHz of additional spectrum to fulfill the enormous increase in mobile broadband data demands.

• 무역학회지
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• 제44권3호
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• pp.43-72
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• 2019

This study examines the trends, current situation and implications of non-tariff measures (NTM) and specific trade concerns (STC) on the protection trade measures of ASEAN. ASEAN's non-tariff measures and the share of specific trade concerns are very significant as they are the second and third largest, respectively, of the major countries. This means that protection measures using non-tariff measures are a strong feature of ASEAN's trade policy. Also, in the future, ASEAN should try to prevent unnecessary disputes caused by exporting countries' specific trade concerns in the implementation of non-tariff measures. Activating trade policy cooperation is likely to reduce conflicts and costs caused by these trade disputes.

• 보건행정학회지
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• 제31권2호
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• pp.145-147
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• 2021

The ethical environment in academic research is rapidly changing at a global level. Further, social expectations and public interest toward research ethics are also escalating in Korea. Understanding and applying ethical issues in academic research has become increasingly important. To conform to such changes in the ethical environment, the official journal of the Korean Academy of Health Policy and Management has been consistently establishing and modifying rules and principles regarding research ethics. For instance, we amended the submission guidelines to further address the policies for gendered innovations. For this editorial of the current issue, we would like to organize and share several ethical concerns, which recently gained considerable attention. We hope this review provides scholars with practical guidelines to comprehend and incorporate critical ethical issues into academic research.