• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.5 s.335
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• pp.47-54
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• 2005

This paper proposes and analyzes a Tag Anti-collision algorithm in RFID system. We mathematically compare the performance of the proposed algorithm with existing binary algorithms(binary search algorithm, slotted binary tree algorithm using time slot, and bit-by-bit binary tree algorithm proposed by Auto-ID center). We also validated analytic results using OPNET simulation. Based on analytic result, comparing the proposed Improved bit-by-bit binary tree algerian with bit-by-bit binary tree algorithm which is the best of existing algorithms, the performance of Improved bit-by-bit binary tree algorithm is about $304\%$ higher when the number of tags is 20, and $839\%$ higher when the number of tags is 200.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.3
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• pp.387-392
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• 2014

Now a days, there are various application functions to transmit from vehicles to the Internet and vice versa. And the communication can be operated through a roadside infrastructure including with possible use of routing protocols. Specifically, autonomous vehicles for remote driving and monitoring requires transmitting of high depth of multimedia such as video. Especially in a populated urban area, an efficient network is vital because of handling a great amount of the data. Therefore, in this paper, efficient network topology for a crossroad in urban area is suggested by performance evaluation of vehicular networks using a wireless LAN and a routing protocol. For the performance evaluation, various vehicular network topologies are designed and simulated in OPNet simulator.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.3
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• pp.329-334
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• 2014

Recently, various electronic functions are developed for car drivers as the advent of electrical automobile. Especially, there are functions to examine for preventing drowsy or healthcare through monitoring brainwave(EEG) of drivers in real time. This function can be provided by transmitting driver's EEG, and the network function for transmission among cars or between car and road side infrastructure is a vital issue. Therefore, in this paper, to provide efficient routing protocol for transmitting EEG data at a cross road in an urban area, 5 different wireless communication network applied each routing protocol such as AODV, DSR, GRP, OLSR, and TORA is designed and simulated in the OPNet network simulator, then it is evaluated for the result.

• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.97-106
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• 2005

Generally, network QoS is determined by timeliness, bandwidth, and reliability, As IT technologies are growing day by day, the bandwidth and reliability factors are expected to be able to satisfy user's requirements. The timeliness factor, however, has not fully met user's requirements yet. In this paper, we propose a packet forwarding scheme named POSIA (Packet forwarding Scheme based on Interworking Architecture) that can provide quite a good QoS (quality of service) by minimizing processing time which is the major part of the timeliness factor. Based on path and resource reservation mechanism, the proposed POSIA makes routers on the packet forwarding path synchronize with each other and then forward packets, The POSIA has been verified to outperform the existing MPLS packet forwarding scheme through computer simulations using OPNET.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.8
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• pp.915-920
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• 2015

Recently, many companies try to offer various services using drones. Especially, the drone delivery system is a good example. However, the drone delivery service has some problems since the heavy parcels flies over the people walking down streets, so many things must be considered such as dropping mails by collision of drones. To resolve the problem, in this paper, a inter-drone network communication will be used to design the topology and to simulate in the Opnet simulator for the performance evaluation. Additionally, the topology with random mobility of trajectory of drones is also designed and simulated for the result.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.9
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• pp.923-928
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• 2016

The various technologies related to the monitoring human health in real-time for the emergency situations are developing these days. Mostly the human pulse is used for measuring as the vital signs so far, but the EEG became a major research trend now. However, there are some problems measuring and sending EEG signals of all the people walking down the street to the dedicated server. Especially, there are some restrictions for collecting and sending EEG signals in 2-dimensional space in real-time. Therefore, I suggests an efficient network model using 3-dimensional space of drones to avoid the restrictions. The models are designed, simulated, and evaluated with the Opnet simulator.

• 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 Korea Information Processing Society Conference
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• 2017.04a
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• pp.97-100
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• 2017

As part of overseas defense program of the US's Trump administration, the military allies were asked to cover partial operation costs for the weaponry deployed at the US bases in their countries. This raised the Korean government's, as well as defense industry's interest in constructing a tactical/strategic communication network and investments are being made actively. Thus, in this study, the performances of WiMAX and WLAN have been compared and a tactical/strategic communication network has been constructed for simulation by using OPNET. As a result, the simulation for the network using combat tanks was successful. An average communication distance that can be achieved by WLAN in open terrain is about 200m as it has been designed on the premise of short-range wireless communications. When the distance was increased to 1km, the tanks could not receive data. By contrast, it was able to confirm that the WiMAX-based network has allowed smooth communications at the same distance. Based on this result, it can be concluded that using WiMAX for tactical operations will have much more merit than adopting WLAN as far as the distance is concerned.

• The KIPS Transactions:PartC
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• v.17C no.6
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• pp.451-458
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• 2010

To detect and recover packet losses over wireless links is very important in terms of reliability in packet transmission. Most wireless communication systems adopt an automatic repeat request (ARQ) protocol operating at link layer. However, it has been constantly addressed that the interaction not harmonized sufficiently between ARQ and TCP rather degrades TCP performance. In this paper, therefore, we propose an improved scheme from the aspect of the interaction with TCP loss recovery mechanism that can be applied to selective repeat ARQ (SR-ARQ) protocol and prove that the proposed scheme improves TCP performance significantly by OPNET simulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.280-286
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• 2009

The NGN(Next-Generation Network) structure has been considered from various points of view as all If wireless-wired integration network and its performance is one of the main issue in these days. In this paper, various wired and wireless integrated networks with voice service are designed and simulated to obtain problems and factors affects the network performance using OPnet simulator. The characteristics only showed in the wired and wireless integrated networks are measured and analyzed compared with the single networks such as a wired or wireless networks. Especially, in the wired and wireless integrated networks showed degrading performance even if there are few transmissions in the network and furthermore, the various networks of increasing numbers of the nodes and transmission are simulated and evaluated.