• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.147-150
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• 2004

In this paper, we propose a reduced-state sequence estimation (RSSE) for trellis coded modulation (TCM) in OFDM with two-stage IDFT/ DFTs, MMSE-LE, and interleaving on frequency selective Rayleigh fading channels. The Viterbi algorithm (VA) is used to search for the best path through the reduced-state trellis combined with equalization and TCM decoding. Computer simulations confirm the bit error probability of the proposed scheme.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.949-952
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• 2005

We propose the hardwired distributed arithmetic which is applied to multiple constant multiplications and the fixed data path in the inner product of fixed coefficient as a result of variable radix-2 multi-bit coding. Variable radix-2 multi-bit coding is to reduce the partial product in constant multiplication and minimize the number of addition and shifts. At results, this procedure reduces the number of partial products that the required multiplication timing is shortened, whereas the area reduced relative to the DA architecture. Also, this architecture shows the best performance for DCT/IDCT and DWT architecture in the point of area reduction up to 20% from reducing the partial products up to 40% maximally.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.59-67
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• 2009

This paper proposes a improved bitmap routing protocol, which finds the best energy efficient routing path by minimizing the network overheads and prolongs the overall network lifetime. Jung proposed a bitmap scheme for sensor networks. His scheme uses a bitmap table to represent the connection information between nodes. However, it has a problem that the table size is depends on the number of nodes in the sensor networks. The problem is very serious in the sensor node with a limited memory. Thereby, this paper proposes a improved bitmap routing protocol to solve the problem in Jung's scheme. Proposed protocol over the memory restricted sensor network could optimize the size of bitmap table by applying the deployed network property. Proposed protocol could be used in the diversity of sensor networks due to it has minimum memory overheads.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.3-8
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• 2002

An intelligent polishing robot automation system is developed. Automatic Tool Change System(A.T.C.), Tool Posture Angle Control, and Robot Program for Polishing Application are developed and integrated into a robotic system that consists of a robot, pneumatic finding tool, and finding abrasives (papers and special films). A.T.C. is specifically designed to exchange whole grinding tool set for complete unmanned operation. Tool Posture Angle Control is developed to give a certain skew angle rather than right angle to tools on the surface for best finishing results. A.T.C. and Tool Posture Angle Control is controlled by a PC and the robot controller. Also, there have been some considerations on enhancing the performance of the system. Some elastic material is inserted between the grinding pad and the holder for better grinding contact. The robot path data is generated automatically from the NC data of previous machining process.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.2
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• pp.303-311
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• 1996

The Self Healing Ring (SHR) is one of the most Intriguing schemes which provide survivability for telecommunication networks. To design a cost effective SONET ring it is necessary to consider load balancing problems by which the link capacity is determined. The load balancing problem in SONET ring when demand splitting is not allowed is considered in this paper. An efficient algorithm is presented which provides the best solution starting from various Initial solutions. The initial solution is obtained by routing ell demands such that no demands pass through an are In the ring. The proposed algorithm iteratively improves the Initial solution by examining each demand and selecting the maximum load are in its path. The demand whose maximum arc load is biggest is selected to be routed in opposite direction. Computational results show that the proposed algorithm is excellent both in the solution quality and in the computational time requirement. The average error bound of the algorithm is 0.11% of the optimum and compared to dual-ascent approach which has good computational results than other heuristics.

• Korean Journal of Geomatics
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• v.3 no.2
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• pp.123-128
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• 2004

As the applied fields of GIS are expanded to the transportation, developing internet-based applications for transportation information is getting attention increasingly. Most applications developed so far are primarily focused on guidance systems for owner-driven cars. Although some recent ones are devoted to public transportation systems, they show limitations in dealing with the following aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggest the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints.

• Journal of the Korean Operations Research and Management Science Society
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• v.5 no.1
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• pp.73-88
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• 1980

It is hoped that this paper may be a contribution to the solution of further problems arising from the gap between theory and practice. The practical cases in the application of PERT.CPM in Korea was investigated and studied. And the results are presented. These examinations of the actual cases led to a conclusion that in order to apply effectively PERT.CPM and to diminish the gap between the planning and actuality, emphasis must be given to the second factors rather than the first one shown on the network diagram, in the course of the control of the work. These second factors are PERT Status Analysis Report, PERT Emergency and PERT Count Down etc. They are the best methods that can eliminate difficult elements on the critical path, by making the maximum use of slack time.

• Bulletin of the Korean Mathematical Society
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• v.46 no.3
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• pp.521-534
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• 2009

In this paper we present new large-update primal-dual interior point algorithms for $P_*$ linear complementarity problems(LAPS) based on a class of kernel functions, ${\psi}(t)={\frac{t^{p+1}-1}{p+1}}+{\frac{1}{\sigma}}(e^{{\sigma}(1-t)}-1)$, p $\in$ [0, 1], ${\sigma}{\geq}1$. It is the first to use this class of kernel functions in the complexity analysis of interior point method(IPM) for $P_*$ LAPS. We showed that if a strictly feasible starting point is available, then new large-update primal-dual interior point algorithms for $P_*$ LAPS have $O((1+2+\kappa)n^{{\frac{1}{p+1}}}lognlog{\frac{n}{\varepsilon}})$ complexity bound. When p = 1, we have $O((1+2\kappa)\sqrt{n}lognlog\frac{n}{\varepsilon})$ complexity which is so far the best known complexity for large-update methods.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.436-439
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• 2008

멀티호밍 기술은 유비쿼터스 네트워크에서 중요한 기술 중 하나이며 이를 이용한 다양한 네트워크 서비스 시나리오들이 제안되고 있다. 따라서 멀티호밍 환경에서 가장 중요한 경로의 설정 방법, 관리 그리고 대체 경로 설정에 관한 연구가 필요하다. 본 논문에서는 기존 가용대역폭 측정방법을 이용하여 각각의 경로의 가용대역폭을 측정하여 단말이 가지는 여러 경로 중 가장 최상의 경로를 결정하는 메커니즘을 제안 한다. 이를 위해 기존의 가용대역폭 측정방법들이 가지는 측정 속도의 문제와 정확한 가용대역폭의 계산을 위한 새로운 알고리즘을 제시하고 이를 이용 단말에서 실시간으로 수신측과 연결되어 있는 경로들에 대한 네트워크의 상태를 파악하여 최적의 경로 설정 메커니즘을 제안한다.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.56-58
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• 1993

This report describes the high speed DC motor (8,000 rpm) that we have designed, manufactured and tested. DC motor is the best drive system in electric-mechanical energy conversion. The design concept for high speed and high energy density to DC motor is to maximize Ampere-conductor in armature and to maximize flux density in armature teeth, armature core, pole, yoke using flux path.