• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.206-209
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• 2014

Control message exchange is major job for cognitive radio to exist and use spectrum opportunistically. For this control message exchange they need a common control channel (CCC). Once this channel is affected by a primary user, communication stops until new CCC is setup. This takes substantial time and if they could not get free channel, this halt continues for long time. To prevent such cease of communication, we propose a combination of two networks, namely WLAN and UWB, to let the communication continue. In our proposed idea if the CCC of a certain CR in WLAN is affected, the CR changes its network from WLAN to UWB and keeps the communication because UWB cannot be affected by PU. In the proposed idea every cognitive radio has two transceivers; one for the overlay network (WLAN) and another UWB network. If a primary user is detected in the spectrum of a cognitive radio, it continues exchanging control messages under the UWB network and in parallel negotiates for a new CCC using the WLAN network. This idea solves the communication interruption until new CCC is setup.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2565-2568
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• 2003

This paper presents a behavioral data monitoring system based on WAP(wireless application protocol) service for the 24-hour continuous health state monitoring of the elderly and the disabled. The developed system transmits a character message to the predefined mobile cell phone through SMS service when an emergency state takes place. Simultaneously, the image captured by a CCD camera is transmitted to the server computer installed WAP service program. Then, the user of the cell phone who received he message can access the server and open the transmitted image. This system can be used for the effective health monitoring of the elderly and disabled.

• ETRI Journal
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• v.17 no.1
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• pp.23-36
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• 1995

We present a performance evaluation model of cell reassembly mechanism in an ATM switching system. An ATM switching system may be designed so that communications between processors of its control part can be performed via its switching network rather than a separate inter-processor communications network. In such a system, there should be interface to convert inter-processor communication traffic from message format to cell format and vice versa, that is, mechanisms to perform the segmentation and reassembly sublayer. In this paper, we employ a continuous-time Markov chain for the performance evaluation model of cell reassembly mechanism with individual buffering, judicially defining the states of the mechanism. Performance measures such as message loss probability and average reassembly delay are obtained in closed forms. Some numerical illustrations are given for the performance analysis and dimensioning of the cell reassembly mechanism.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.1
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• pp.72-79
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• 2013

In wireless sensor networks, the selective wakeup scheme is one of the energy saving mechanisms, that is used for an object detecting or tracking. Recently, many protocols are proposed using the selective wakeup scheme for the continuous objects tracking such as forest fires and poison gas. They predict the future shape of continuous objects and activate only sensors in the predicted boundary area of the objects. It works correctly in a uniformly deployed wireless sensor networks. However, it cannot be directly applied to a randomly deployed sensor networks with voids. When the predicted area is in the void area, the activation message cannot reach and the predicted area cannot be activated at the right time. It leads to many detection errors for continuous object. Moreover, if a sensor is once foiled in a activation control then the next activation control might be continuously failed. The detection errors can be result in serious harm to people. In this paper, we propose a chaining selective wakeup scheme for robust continuous object tracking in wireless sensor networks. In our protocol, we collect the information of a void area during the network configuration time; if the next boundary area is in the void area, we activate the chained area surrounding the void area with activation control message.

• The Research Journal of the Costume Culture
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• v.22 no.6
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• pp.1011-1027
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• 2014

The purpose of this study is to analyze the factors that lead to continuous use intention of SNS marketing. The research model was designed to investigate the SNS factors that affect use intention based on TAM (Technology Acceptance Model) suggested by Davis (1986). The survey focused on age twenties to thirties male and female who had experience in receiving fashion brands message through Facebook. 329 questionnaires were used to analyze the results of study, and SPSS 12.0 was used to conduct factor analysis, reliability analysis, and multiple regression analysis. The results of this research are as follows. First, interaction/playfulness, information, reliability, and convenience of access were extracted as the characteristics of fashion brands SNS marketing. Second, all SNS factors had significant relation on perceived usefulness. But only interaction/playfulness and convenience of access showed significant relation on perceived ease of use. Third, perceived usefulness and perceived ease of use affected continuous use intention. Forth, continuous use intention had significant relation on brand attitude and showed direct and indirect significant relation to purchase intention.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.5
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• pp.506-512
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• 2000

In this paper, we propose a Fuzzy Classifier System(FCS) makes the classifier system be able to carry out the mapping from continuous inputs to outputs. The FCS is based on the fuzzy controller system combined with machine learning. Therefore the antecedent and consequent of a classifier in FCS are the same as those of a fuzzy rule. In this paper, the FCS modifies input message to fuzzified message and stores those in the message list. The FCS constructs rule-base through matching between messages of message list and classifiers of fuzzy classifier list. The FCS verifies the effectiveness of classifiers using Bucket Brigade algorithm. Also the FCS employs the Genetic Algorithms to generate new rules and modifY rules when performance of the system needs to be improved. Then the FCS finds the set of the effective rules. We will verifY the effectiveness of the poposed FCS by applying it to Autonomous Mobile Robot avoiding the obstacle and reaching the goal.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.37 no.5
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• pp.1-10
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• 2000

In this paper, we propose a Fuzzy Classifier System(FCS) makes the classifier system be able to carry out the mapping from continuous inputs to outputs. The FCS is based on the fuzzy controller system combined with machine learning. Therefore the antecedent and consequent of a classifier in FCS are the same as those of a fuzzy rule. In this paper, the FCS modifies input message to fuzzified message and stores those in the message list. The FCS constructs rule-base through matching between messages of message list and classifiers of fuzzy classifier list. The FCS verifies the effectiveness of classifiers using Bucket Brigade algorithm. Also the FCS employs the Genetic Algorithms to generate new rules and modify rules when performance of the system needs to be improved. Then the FCS finds the set of the effective rules. We will verify the effectiveness of the poposed FCS by applying it to Autonomous Mobile Robot avoiding the obstacle and reaching the goal.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.549-552
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• 2003

In this paper, an efficient architecture of a versatile Reed-Solomon (RS) decoder is designed, where the message length k as well as the block length n can be variable. The decoder permits 3-step pipelined processing based on the modified Euclid's algorithm(MEA). A new architecture for the MEA is designed for variable values of error correcting capability t. To maintain the throughput rate with less circuitry, the MEA block uses both the recursive and the overclocking technique. The decoder can decode a codeword received not only in a burst mode, but also in a continuous mode. It can be used in a wide range of applications due to its versatility. A versatile RS decoder over GF(2$^{8}$ ) having the error-correcting capability of up to 10 has been designed in VHDL, and successfully synthesized in an FPGA chip.

• Journal of the Korea Society of Computer and Information
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• v.28 no.3
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• pp.45-58
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• 2023

KVMF(Korean Variable Message Format) 1.0 protocol is the Army's standard tactical datalink protocol that defines standard messages and communication methods to enable data communication between various weapon systems through bitwise variable message processing. The protocol has been applied to a variety of Army weapon systems over the past decade and has contributed to upgrade the Army's operational capabilities by enabling the implementation of Network Centric Warfare (NCW), the core of modern warfare. Since the KVMF 1.0 protocol was applied, new weapon systems with new technologies have been introduced over time, and new weapon systems have new messages based on the characteristics of the weapon system. As a result, compatibility problems arose due to different message versions with existing weapon systems, and it was expected that these problems would continue to emerge in the future, considering the need for continuous message revisions. Therefore, it became necessary to solve this problem, so this paper proposed a KVMF 2.0 protocol design that guarantees compatibility between forward and backward versions. In this paper, we implemented the design as SW, and confirmed that the design worked successfully by test between forward and backward versions on test environment. Therefore, when the KVMF 2.0 protocol design is applied to a weapon system, we can expect that the weapon system can be compatible with the forward and backward versions working with the existing weapon systems as well as with the future weapon systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1689-1706
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• 2012

The preservation of temporal dependencies among a group of processes that exchange continuous media at runtime is a key issue for emerging mobile distributed systems (MDS), such as monitoring of biosignals and interactive multiuser games. Although several works are oriented to satisfy temporal dependencies, most of them are not suitable for MDSs. In general, an MDS is characterized by the absence of global references (e.g. shared memory and wall clock), host mobility, limited processing and storage capabilities in mobile hosts, and limited bandwidth on wireless communication channels. This paper proposes an asymmetric synchronization protocol to be used at runtime in an MDS without using a common reference. One main aspect of our synchronization protocol is that it translates temporal constraints to causal dependencies of the continuous media data as seen by the mobile hosts. We simulate the protocol by considering a cellular network environment and by using MPEG-4 encoders. The simulation results show that our protocol is effective in reducing the synchronization error. In addition, the protocol is efficient in terms of processing and storage costs at the mobile devices, as well as in the overhead attached per message across the wired and wireless channels.