• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.8-14
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• 2009

A lamp which is currently employed to LCD(Liquid Crystal Display) Backlight is almost CCFL(Cold Cathod Fluorescent Lamp) and EEFL(External Electrode Fluorescent Lamp). However, the use of these lamps is being restricted as RoHS(the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment) regulation is gradually reinforced. According to this situation, the manufacturing of a lamp which doesn't use mercury is unescapable. Moreover, LCD TV has a defect which take place Motion Blur phenomenon due to response time of LC(Liquid Crystal), and Hold-type characteristic which only exists in LCD differently to CRT, PDP. In this paper, an inverter is proposed to drive a plane light source lamp which is not containing mercury. Driving circuit of proposed inverter is simple because the number of semiconductor device and magnetic device is reduced by using forward topology. Also, Motion Blur phenomenon is decreased by dividing the plane light source lamp to six block along vertical direction, and scanning. Finally, we proved usefulness of proposed inverter through experiment.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.1
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• pp.22-33
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• 1999

In this paper, we propose a new multi-way circuit partitioning system that partition large circuits to progrmmable circuit board which consist of FPGAs and interconnect components. Here the routing topology among the chips are predetermined and the number of available interconnections are fixed. Since the given constraints are difficult to be satisfied by the previous partition method, we suggest a new multi-way partition method by target restriction that considers all the constraints for the given board. To speed up, we construct a multi-level cluster tree for hierarchical partitioning. Experimental results for several benchmarks show that the our partition method partition them by satisfying all the given constraints and it used up to 10 % fewer interconnections among the chips than the previous K-way partition method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3A
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• pp.269-278
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• 2010

There are tendency that wireless sensor network is one of the important techniques for the future IT industry and thereby application areas in it are getting growing. Researches based on the hierarchical network topology are evaluated in good at energy efficiency in related protocols for wireless sensor network. LEACH is the best well known routing protocol for the hierarchical topology. However, there are problems in the range of message broadcasting, which should be expand into the overall network coverage, in LEACH related protocols. This dissertation proposes a new routing protocol to solve the co-shared problems in the previous protocols. The basic idea of our scheme is using the table for nodes connectivity and node energy information. The results show that the proposed protocol could support the load balancing by distributing the clusters with a reasonable number of member nodes and thereby the network life time would be extended in about 1.8 times longer than LEACH.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.89-92
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• 2005

Centralized P2P system, Napster and Unstructured P2P system, Gnutella accomplish main current. Centralized system and unstructured system have a restriction in a scalability. To solve the this problem, structured system is appeared. CAN, Chord, Pastry and Tapestry are delegation of this system. Although structured system don't aware physical proximity of node because it uses Distribute Hash Table. In proposing system, a node can communicate with physical proximity of node using concept of LAN. Internet traffic is also decreased because communication in the Chord network divide in two(original network and sub network).

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.308-314
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• 2015

This paper has proposed a new boost rectifier. Adequate input current was obtained by keeping the duty ratio constant without complicated conventional control methods and the improvement of the waveform was increased. With a decrease of distortion up to 12.9[%], the scope of restriction on harmonics was set to 13.0[%]($3^{td}$ harmonics), 1.1[%]($5^{td}$ harmonics) and 0.6[%]($7^{td}$ harmonics), respectively. Because complicated methods of control are avoided, the circuit configuration is simple and practical. In particular, the said effect turned out to be highly efficient in the low boosting ratio range(boosting ratio$({\alpha})=1.25$). The feasibility of these facts has been proven both theoretically and experimentally.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1538-1545
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• 1998

System reliability has been a major concern since the beginning age of the electronic digital computers. One of the modest ways of increasing reliability is to design fault-tolerant system. This paper propose a construction mechanism of fault-tolerant system for the general graph topology. This system has several spare nodes. Up to date, fault-tolerant system design is applied only to loop and tree networks. But they are very limited cases. New algorithm of this paper tried to have a capability which can be applied to any kinds of topologies without such a many restriction. the algorithm consist of several steps : minimal diameter spaning tree extraction step, optimal node decision step, original connectivity restoration step and finally redundancy graph construction step.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.359-366
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• 2016

Today's multi-core technology rapidly increases with more and more Intellectual Property cores on a single chip. Network-on-Chip (NoC) is an emerging communication network design for SoC. For efficient on-chip communication, routing algorithms plays an important role. This paper proposes a novel multicast routing technique entitled as Docket NoC (Dt-NoC), which eliminates the need of routing tables for faster communication. This technique reduces the latency and computing power of NoC. This work uses a CURVE restriction based algorithm to restrict few CURVES during the communication between source and destination and it prevents the network from deadlock and livelock. Performance evaluation is done by utilizing cycle accurate RTL simulator and by Cadence TSMC 18 nm technology. Experimental results show that the Dt-NoC architecture consumes power approximately 33.75% 27.65% and 24.85% less than Baseline XY, EnA, OEnA architectures respectively. Dt-NoC performs good as compared to other routing algorithms such as baseline XY, EnA, OEnA distributed architecture in terms of latency, power and throughput.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7B
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• pp.659-667
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• 2009

Mobile Ad-hoc Network consists of mobile nodes without immobile base station. In mobile ad-hoc network, network cutting has occurred frequently in node because of energy restriction and frequent transfer of node. Therefore, it requires research for certain techniques that react softly in topology alteration in order to improve reliability of transmission path. This paper proposes path selection techniques to consider mobility of node that respond when search path using AOMDV routing protocol. As applying proposed techniques, We can improve reliability and reduce re-searching number of times caused by path cutting.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.2
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• pp.10-17
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• 2008

In this paper, we propose an efficient data replication strategy based on Peer-to-Peer which improves the performance of Data Grid system. The key idea of this replication strategy is to add the Peer-to-Peer concept for reducing data transmission restriction caused by hierarchical topology. And, it makes the nodes can store data replica to set a critical section at the storage of client level nodes. Therefore, it is possible to transmit the data replica between client level nodes and from client level nodes to upper data replication server. It is more effective to transmit data replica between client level nodes than transmitting data replica 1mm data server or data replication server with respect to minimize the transmission time. This results in improving the performance of Data Grid system. Through simulation, we show that the proposed data replication strategy based on Peer-to-Peer improves the performance of entire Data Grid environment compared to previous strategies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.6
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• pp.558-571
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• 1992

In this paper, we propose an improved method of state exploration called the extended circular exploration (ECE) for the efficiency of state exploration and the reduction of explosively growing state. The ECE does not need to explore all the reachable global states, and It can be applied to JV($\boxDr$$\geq$ 2) -party protocol with alternative routes, i.e., it is applicable to the protocol In which adaptiverouting mechanism can be performed. The ECE eliminates a restriction of topology of the conventional circular exploration(CE) by exploring only those global states which are reachable, provided that the participant processes of any group of transitions proceed at the same speed, and that they can be formed as a cycle. Thus the state space explored if not exhaustive. The algorithm presented can detect deadlock error and unspecified reception error It requires storage space and /or execution time much less than those of the conventional perturbation(CP) . It might be used for a solution of the N-process collision and the interference mechanism.