• The Journal of Korean Institute of Communications and Information Sciences
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• 제38A권10호
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• pp.908-917
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• 2013

In this paper, we propose a discovery protocol for finding nearby mobile applications and services in a device-to-device communications system. The device-to-device communication technology enables proximity-based services such as mobile social networks and mobile marketing. For realizing these proximity-based services, it is essential to design a discovery protocol which pinpoints the devices with mobile applications of interest among hundreds and thousands of devices in proximity. In the infrastructure-less networks such as ad hoc networks, we can design the discovery protocol that periodically broadcasts a short discovery code containing the compressed information of the mobile applications. In this paper, we design the discovery protocol with the discovery code generated by using a hash function and a Bloom filter. We also mathematically analyze the performance of the proposed protocol.

• Transactions on Control, Automation and Systems Engineering
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• 제3권4호
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• pp.223-228
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• 2001

We have been developed an intelligent mobile robot with an artificial olfactory function to recognize odours and to track odour source location. This mobile robot also has ben installed an engine for speech recognition and synthesis and is controlled by wireless communication. An artificial olfactory system based on array of 7 gas sensors has been installed in the mobile robot for odour recognition, and 11 gas sensors also are located in the obttom of robot to track odour sources. 3 optical sensors are also in cluded in the intelligent mobile robot, which is driven by 2 D. C. motors, for clash avoidance in a way of direction toward an odour source. Throughout the experimental trails, it is confirmed that the intelligent mobile robot is capable of not only the odour recognition using artificial neural network algorithm, but also the tracking odour source using the step-by-step approach method. The preliminary results are promising that intelligent mobile robot, which has been developed, is applicable to service robot system for environmental monitoring, localization of odour source, odour tracking of hazardous areas etc.

• Journal of Advanced Navigation Technology
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• 제15권3호
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• pp.355-363
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• 2011

Transcoding in the wireless mobile network is an important mechanism that reduces the delay time and improves the stream processing capacity. Wireless mobile streaming media services, however, have such problems as congestion, interference and delay due to narrow network bandwidth and limited resources. These problems degrade not only Quality of Service (QoS) but also responsiveness of the streaming media service. To solve this problem, this paper proposes a object version transcoding method. The proposed method analyzes the object versions to construct the transcoding graph. This paper utilizes a reference rate-based control function for an efficient streaming, and measures MVDS(Multiple Version Delay Saving) for an efficient delay savings. The simulation results show that the proposed mechanism achieves improved performance in delay rate and cache hit rate compared with those of other existing methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제9권8호
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• pp.1691-1695
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• 2005

Mobile P2P Service can compose free network from one client to another without central server function. Diversified Information & Data are able to be transmitted among peer to peer based upon extended mobile concept. In this paper Mobile P2P Service is applied to the program which gathering, sharing, analysis agricultural information and the natural disasters Information We desire to authenticate request about service to user who is administered between each user to limit connection. Wish to admit authentication mechanism to mechanism that can do information sharing suety in P2P environment to solve this in this treatise and design authentication mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제13권8호
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• pp.3680-3686
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• 2012

This research suggests a monitoring method to support QoS of mobile multimedia services effectively based on information gathering. It means a method in which a subscriber's terminal collects information about its current condition and its surrounding base stations, and a base station, through the data collected by monitoring inner or adjacent base station, shares related data and converges, controlling QoS on its own. In other words, as context information of mobile terminal and base station changes, set-up of related functions and QoS mapping is adapted; each function fits into the change, exchanges the process of reorganization, and interacts; these actions go toward to satisfy service continuity.

• Journal of the Korean Society of Safety
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• 제28권3호
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• pp.11-17
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• 2013

Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate the mobile crane's overturn accident in terms of the forensic engineering, in this study, we identified the accident mobile crane's position and posture before accident by the analysis of the trace resulted by the contact between the outrigger and the ground, and the accident remodeling has been performed using CATIA modeling program in the basis of the accident mobile crane's position and posture information. The accident analysis has been performed by comparing this accident remodeling and the crane's specification, the table of the allowance load about the boom's length and the working radius. Through these studies, the safety accident that may occur in mobile crane can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

• Journal of Information Technology Services
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• 제13권2호
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• pp.1-17
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• 2014

Social networking service (SNS) is a service that allows people to share information, manage relationships with others, and express themselves on the Internet. The number of SNS users have increased explosively with the growth of mobile devices such as smartphones. As the influence of SNS has grown extensively, potential threats to privacy have also become pervasive. The purpose of this study is to empirically examine the main factors that affect users' intentions to use security functions provided by their SNS. The main theories for this study include the rational choice theory and the theory of planned behavior. This study has identified the factors that affect intention to use security functions. In addition, security function awareness and information security awareness are found to be important antecedents for intention to use security functions. The results of this study implies that when SNS providers develop security policies, they should consider the ways to improve users information security awareness and security function awareness simultaneously.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제19권2호
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• pp.105-115
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• 2009

At the most recent, IPTV service is increasing, which isa communicative broadcasting fusion service that provides various multimedia contents interactively followed by user's request through super high-speed internet. For IPTV user service with high mobility, IPTV user's enrollment is essential. However, IPTV service provided to mobile users can't provide the certification of mobile user securely. This paper proposes light user certification protocol which can certificate mobile users by attaching RFID to IPTV STB for secure awareness of mobile users who get IPTV service. The proposed protocol prevent reply attack and man-in-the-middle attack from happening oftenin a wireless section by transmitting the result value hashed by hash function with both its' ID and random number received from tag after tag transmits random number which generated randomly in the process of certification of mobile user to IPTV STB.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제30권9A호
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• pp.838-849
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• 2005

Fast handover protocol provides seamless handover in mobile Ipv6 networks by reducing handover latency. This paper proposes FMIP-M mechanism to apply this advantage of fast handover protocol to multicast service. The FMIP-M is a fast handover mechanism that supports a reliable multicast service in mobile Ipv6 networks. When hosts move other networks, they may have seine data missing and out-of-synch problems of multicast data. The proposed mechanism provides reliable multicast transmission by compensating data losses from the previous AR. Also it provides an additional function that is able to change multicasting service types dynamically in accordance with network status related with multicasting. So that it is able to make multicast paths very close to the optimum and more efficient multicast service is possible. The performance of the proposed mechanism is evaluated by a time analysis and simulations in various conditions.

• Journal of Distribution Science
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• 제16권4호
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• pp.67-74
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• 2018

Purpose - Most of the amendments to the law on the improvement of the distribution structure of mobile communication terminal equipment, the fully self-sufficient system of terminals, and the separated disclosure system on the terminals are aimed at securing transparency of the distribution structure by eliminating or reducing handset subsidies. This study investigates what items are important for the purchase of mobile phones in various and rapidly changing mobile phone markets from the consumer's point of view and tries to make a strategic suggestion for future mobile distribution strategies. Research design, data, and methodology - The procedure of this study takes place in four steps. In step 1, only the SF type respondents selected for this study were extracted through MBTI analysis. In step 2, they were divided into three hierarchies for the AHP analysis and each element was arranged. In step 3, the AHP analysis was converted to a Fuzzy-AHP number using the trigonometric centroid method. This was to eliminate the ambiguity of the response by converting into a fuzzy number even if data consistency was maintained with CI value below 0.1. In step 4, the number of converted 2-layer and 3-layer was combined to derive the priority when the final handset is selected. Results - First, the highest importance among the four items in the second tier was the terminal function item, followed by brand, price, and design item. Second, in the third tier, the highest importance was level of after-sales service, followed by device price, processing speed, ease of use, usefulness, and rate system. Third, the arithmetic average of the determinant of the fuzzy function showed that processing speed, ease of use and usefulness in the function item, level of after-sales service in the brand item, and device price in the price item were the five most important factors among 16 choice factors. Conclusions - First, there will be a change in the consumption patterns of consumers who have compared distributors and dealers to purchase handsets with more subsidies. Second, it is highly likely that people will purchase new handsets only when they need to change their devices because they can not receive subsidies by switching phone brands any more.