• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2178-2187
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• 2015

Bluetooth Low Energy (Bluetooth LE) is a representative break-through communication technology for wireless personal area networks on nowaday. In this environment, most of significant performance should be aiming to energy efficiency due to the policy for manufacturing light-weighted communication devices derived from requirement of world IoT market, and many researches have been developed to satisfy this requirement. While Bluetooth LE has been leading the low power communication technology required from the current market by employing duty cycle and frequency hopping approaches, it couldn't address the problem of reliability on broadcast transmissions. The main goal of this paper is aiming to addressing this problem by suggesting a new method. Furthermore analytic evaluations would also be proceeded to find objective results in the view point of broadcast transmission efficiency from Master device.

• Journal of KIISE:Software and Applications
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• v.37 no.10
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• pp.736-744
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• 2010

Log data collected from mobile devices contain diverse and meaningful personal information. However, it is not easy to implement a context-aware mobile agent using this personal information due to the inherent limitation in mobile platform such as memory capacity, computation power and its difficulty of analysis of the data. We propose a method of selective inference for modular Bayesian Network for context-aware mobile agent with effectiveness and reliability. Each BN module performs inference only when it can change the result by comparing to the history module which contains evidences and posterior probability, and gets results effectively using a method of influence score of the modules. We adopt memory decay theory and virtual linking method for the evaluation of the reliability and conservation of casual relationship between BN modules, respectively. Finally, we confirm the usefulness of the proposed method by several experiments on mobile phones.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.780-788
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• 2011

This paper suggests one model, which can be monitor and control target system at anytime and anywhere by a WAP and ME based personal cellular phone(Feature phone) and internet connection. The suggesting model tried to overcome constraints of distance and mobility of conventional methods, TCP/IP based remote data monitoring system, which combine PDA and WLAN technologies. For the experiments of suggesting model, the target systems are constructed with individual modules, which need AC or DC power control. The development software for the control and monitor of local system use NI Labview for the easy-programming and confidence. Also, web server use APM setup for the general user. The mobile connection environments of personal cellular phone are programmed by use WML and mHTML language for the general access. Through the experiments, we have showed that suggesting model can overcome constraints of distance and mobility of conventional system.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.4
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• pp.247-264
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• 2016

The purpose of this study is to find the determinants for the type(Franchising or Independent Entrepreneurship) of new venture creation. This study conducted an empirical analysis on a total of 398 samples of survey gathered from people in Seoul, Gyoeng-gi, Daegu, and Gyeonsangbuk-do. This study includes not only personal traits, but also entrepreneurial intention and network as independent variables. Findings of the analysis reported that Entrepreneurial intention, Need for achievement, Autonomy, Entrepreneurship, Self-efficacy, Education, Network, Age, and Income have significant discriminant power, in order of priority, on general two groups of Franchising and Independent Entrepreneurship. However, in the study, autonomy is revealed as the sole discriminant factor on considering venture creation groups. Based on the result, the study contributes theoretical and practical implications in relation to the determinants for the type of franchising or independent entrepreneurship.

• Journal of Information Technology and Architecture
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• v.11 no.1
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• pp.33-44
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• 2014

Recently, blogs have attracted much attention as personal media. The power of blogs as a way to provide valuable resources on Internet is so tremendous because of the high speed of information dissemination and the huge influence of the circulated information on Internet users even when the information itself is not true. Especially, contents on blogs that attract a lot of public attention are sometimes reproduced or magnified in an inappropriate way. In this paper, a method to measure the trust level of contents posted on personal blogs is proposed to reduce the damage of wrong information circulated along with blog networks. Trust variables such as relationship data in SNS are used to measure the comparative trust level of blog contents. The structure of the prototype system is also designed to apply this framework to blogsphere.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.172-180
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• 2016

This study was conducted to evaluate the relations between the exposure level of organophosphates (OPs) pesticide and application factors among rural farmers. The urinary dialkylphosphates, metabolites of organophosphorus pesticides, including DMP, DEP, DMTP and DETP were analyzed by GC/MSD and GC/MS/MS. The DMP and DMTP were detected more in the use of a speed sprayer without cap than with a capped one. Also, the less farmers wore the personal protective equipment (PPE), the more these were detected. The amount of organophosphorus exposure was the highest in the use of a power sprayer. However, it was low when a farmer applied pesticides with a speed sprayer with cap and wore more PPE. In this study, the detection rate was analyzed by chi-square test, the exposure level of OPs was analyzed by a generalized linear model.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.1
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• pp.28-42
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• 2013

Personal Rapid Transit(PRT) is a new unmanned transportation system using electricity. The purpose of the PRT is relieving the congestion of city traffic and connecting between inner city and airport, high-speed railroad. PRT requires to develop devices for the guarantee of safety and reliability. PRT as the mean of rail transportation must be equipped with control system for front rail sensing. Ultra Wide Band(UWB) radar system is suitable for PRT's detection because it has the advantage of low power consumption, low interference and high resolution. In this paper, an improved adaptive Constant False Alarm Rate(CFAR) algorithm is proposed and studied in various noise environments. The proposed algorithm improves performance in various noise environments compared to the Mean Level CFAR algorithms and other adaptive CFAR algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.450-457
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• 2008

One of very essential techniques for enlarging lifetime of energy-constrained wireless personal area network (WPAN) devices is energy-efficient transmission technique. If the WPAN is operated based on a TDMA protocol, the satisfaction of QoS requirements at each allocated time slot is another important factor to be considered. We therefore propose an energy-efficient transmission scheme for WPANs operating with a contention-free medium access protocol such as TDMA, as well as satisfying QoS requirement. The proposed algorithm determines the optimum combination of transmit power, physical data rate and fragment size required to simultaneously minimize the energy consumption and satisfy the required QoS in each assigned time duration, considering all the possible energy-minimization related parameters. The proposed algorithm demonstrated the improved performance results in terms of throughput and energy consumption via computer simulation.

• The Korean Journal of Air & Space Law and Policy
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• v.5
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• pp.171-205
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• 1993

On the contrary to the general principle of private law, carriers' liability for passengers and cargo owners have been quantatively limited in some cases. The author traces the rule of liability limitation in the law of Korea and United States to verify two hypotheses. The first hypothesis is that the rule of liability limitation has been introduced to motivate investment when new technology with high risk has been adopted in business. The second hypothesis is that the rule of liability limitation can be maintained only when damages have been fully compensated. The former is a necessary condition for liability limation, and the latter sufficient condition. There are strong evidences for the first hypothesis. Navigation or aviation, artificial satellite lauching, urban transportation system are good examples. The second hypothesis is supported by the fact that there have been continuous controversies on the Warsaw System, including the failure of ratification of Montreal Additional Protocols No.3 & 4 by the U.S. Senate and voluntary removal of liability limitation by the Japanese airline companies. Loss of cargo can be compensated fully, but damages from personal injury and death not. The value of human body and life is not easy to be estimated. Passengers, moreover, do not usually buy insurance for accidents in travel. Passengers do not accept insurance premium as the cost of being whole and alive. They do not accept accident rates realistically. They have no bargaining power in dealing with insurers. The rule of liability limitation in personal losses would not be supported in future because damages have not fully compensated.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.35-42
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• 2011

WPAN(Wireless Personal Area Network) have many advantages such as using low power and cheap price, small size. So it is recently increasing application range such as personal portable device, home network and sensor network so and on. IEEE 802.15.3 basically has the point to point or peer to peer UM(Usage Model). But using devises that need data transmission is increasing in the house and office. Therefor UM of point to multipoint is proposed. In this paper, I proposed Multicast ACK mechanism on the point to multipoint UM. So it is able to transfer data to multiple devices as this Multicast transfer method at a time. Thus, throughput performance is improved. But the problem that increases data transfer delay is appeared because of adding Multicast ACK traffic. We compared the performance between standard and proposed mechanism through a numerical analysis.