• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.2
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• pp.187-194
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• 2014

In this paper, we analyze the outage probability of macro diversity combining in cellular networks in consideration of aggregate interference from other mobile stations (MSs). Different from existing works analyzing the outage probability of macro diversity combining, we focus on a diversity gain attained by selecting a base station (BS) subject to relatively low aggregate interference. In our model, MSs are randomly located according to a Poisson point process. The outage probability is analyzed by approximating the multivariate distribution of aggregate interferences on multiple BSs by a multivariate lognormal distribution.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.7
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• pp.827-834
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• 2014

In this paper, a triple-band U-shaped monopole antenna with T-shaped stub for WLAN(Wireless Local Area Networks)/WiMAX(World interoperability for Microwave Access) applications. The proposed antenna is based on a planar monopole design, and composed of U-shaped of radiating patch, T-shaped strip in U-shaped, for triple-band operation. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is fabricated. The numerical and experiment results demonstrated that the proposed antenna satisfied the -10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. And characteristics of gain and radiation patterns are determined for WLAN/WiMAX application.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.2
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• pp.71-78
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• 2008

The sensor node's performance is expected to be improved and the price will be largely decreased. As USN-applied field is expanded, multiple application services are expected to be provided through one USN soon. Multiple applications be required a periodic data reporting, consecutive information monitoring, event-driven data and query-based data as the data pattern that USN is delivered. Accordingly, the mechanism which can assure QoS according to each data characteristic is required. In this paper, A proposed protocol apply the duty cycle of S-MAC protocol variably and flexible according QoS level. This method largely reduces the delay on the delay-sensitive traffic, while keeping the energy efficiency.

• Journal of Advanced Navigation Technology
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• v.14 no.1
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• pp.41-48
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• 2010

Intrusion detection forms a vital component of internet security. To keep pace with the growing trends, there is a critical need to replace single layer detection technology with multi layer detection. Different types of Denial of Service (DoS) attacks thwart authorized users from gaining access to the networks and we tried to detect as well as alleviate some of those attacks. We have proposed a novel cross layer intrusion detection architecture to discover the malicious nodes. The information available across different layers of protocol stack are exploited in order to improve the accuracy of detection. We have used cooperative and distributive anomaly intrusion detection with data mining technique to enhance the proposed architecture. The simulation of the proposed architecture is done in OPNET simulator and the results are analyzed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.115-118
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• 2003

In this paper, we analysed the technical characteristics of power line communications interfering marine mobile services. The various radio services including marine mobile potentially affected by unwanted radiation from telecommunication networks as PLT, VDSL, ADSL, etc. The radio spectrum is unique resource. In particular, the frequency range below 30MHz has extremely favourable propagation conditions allowing economic long range as well as low power communication radio services. The paper were as follows to identify marine mobile service that are likely to be affected by PLC and evaluate the protection needs and to investigate methods of measuring the emissions from PLC.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2321-2328
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• 2006

Today, SIP standard (The signalling protocol for the Internet phone service) raises to be the standard technique because the expandability is high and complexity is low. It is widely investigated and actively advocated to use Si81a1 ring protocol for SIP in VoIP service. SIP service can be applied even outside the Internet phone service; instance messaging and various multimedia technology are just an example. This paper proposed an embodiment proxy server for rambling support to use JAIN SIP API. It provides standard interface for testing the Proxy server for SIP and embodiment of user agent that transfer instant massaging and voice communication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.6
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• pp.1242-1249
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• 2012

This paper proposes a metastability-free synchronization method and a mesochronous synchronizer for NoC. It uses the clock transmitted from TX as a strobe and solves the metastability problem by selecting one of rising or falling clock edge depending on the sampling value in RX when the phase difference between clocks is under a metastability window. The logic simulation results show that it works without metastability under $0^{\circ}{\sim}360^{\circ}$ phase difference in the synchronizer that a fault is inserted. The mesochronous synchronizer has a simple control logic and is suitable for NoC.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1265-1270
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• 2011

Different wireless technologies have been developed for various mobile applications. To offer seamless service in next mobile communication systems, it needs handoff service between heterogeneous mobile access networks. A high data rate handoff call from WLAN to cellular mobile network can increase rapidly the blocking probability of BS of cellular mobile network. To solve this problem, this paper proposes a new handoff scheme based on user service profiles. The performances of the proposed scheme are evaluated using computer simulations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1471-1478
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• 2011

A typical standard of vehicular ad hoc networks, WAVE which consists of IEEE 1609.x Family standards and IEEE 802.11p standard, includes the multi-channel coordination and channel synchronization function to provide safety services or public services during a car is driven. Generally, the performance of data communication and networking technologies is evaluated by using simulation tools, such as ns-2, OPNET, OPNET++, etc. However, these tools doesn't provide the operations of WAVE protocol. Therefore, in this paper, we implement and verify WAVE simulation program based on ns-2.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.62-63
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• 2016

A variety of sensors and equipment are installed on passenger ships. Data collection from these sensors and associated equipment is required for the safe navigation and behavior analysis of ships, but when the ship sails out of the area where it is not possible to use the LTE communication, other types of networks have to be able to support to transmit these information. such as AIS, satellite communication and MF/HF. In this paper, we survey data protocol of onboard sensors and design ASM messages to transfer sensor data on board to the shore-side system.