• Tunnel and Underground Space
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• v.13 no.5
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• pp.403-411
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• 2003

Controlled tunnel blasting by deck charge was suggested and simulated by PFC and FEM analyses. Analyzed results showed that suggested method is efficient in fragmentation and able to decrease in vibration level because of decreased amount of charge per delay and dispersion of deck charge. This phenomena was explained by failure mechanism and proved that it can be successfully applied to tunnel blasting.

• ETRI Journal
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• v.35 no.5
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• pp.775-785
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• 2013

Because of their exclusive features, millimeter wave directive mesh networks can be considered for small cell backhaul support in urban environments. For this purpose, a network of closely spaced stations has been considered with very directive line-of-sight links operating in the 60-GHz band. An attempt is made to evaluate channel response and interference behavior in such a network, taking into account the effect of building blockage. A simple grid of building blocks is considered as the propagation environment, and wave propagation is simulated using 2.5-dimensional (2.5D) ray tracing (2D with ground effect) to calculate the received signal at different nodes in the network. The results are compared with free space predictions and used to evaluate interference at all nodes in the channel and describe certain characteristics of links, such as the delay profile and the correlation length.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.117-120
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• 2002

A single DSP implementation of 3D sound movement is described. With the use of a realtime 3D acoustic image localization algorithm, an efficient approach is devised for synthesizing the 3D sound movement by interpolating only two parameters of "delay" and "gain". Based on this algorithm, the realtime 3D sound synthesis is performed by a commercially available 16-bit fixed-point DSP with computational labor of 65 MIPS and memory space of 9.6k words, which demonstrates that the algorithm call be used even for the mobile applications.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1193-1196
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• 2005

In this paper, we presents a new multimedia service transmit method using IPv6. The IPv6 provides the address system of 128 bit and the address space which is infinite it provides. But it will not become the IPv4 and interchange not to be, it uses the DSTM Transition mechanism which will reach and the IPv4 center in the packet header the service type it will be able to support the service class of multi type (TOS) it secures the weak point of data transfer delay it puts a base in the IPv6. The efficiency of this proposed technique have been proven by MPEG-4 streaming video streaming of the IPv6 namely, 6Xtream embodied a order form/live streaming server and the client which it uses to be possible in base and real-time decoding method.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.741-744
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• 2000

본 논문에서는 고밀도 DVD(Digital Versatile Disc) 시스템(4.7GB～l5GB)을 위한 신호 검출기법을 제안하고 FPGA로 구현한다. 본 논문에서 제안하는 FDTrS/DF (Fixed Delay Trellis Search with Decision Feedback)는 트렐리스 구조를 사용하므로 FDTS/DF나 SSD/DF(Signal Space Detection with Decision Feedback)와 같이 이진 가지 구조를 사용하는 신호검출방식에 비해 더 나은 성능을 얻을 수 있다. 또한 FDTrS/DF는 한 단의 트렐리스 구조를 사용해 역추적을 하지 않으므로 하드웨어의 복잡도와 속도면에서 향상된 결과를 얻을 수 있다. 또한 본 논문에서는 하드웨어 구현 시 동작 속도의 향상을 위해 파이프라인 기법과, 계산량 감소를 위해 절대값 분기거리를 사용한다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.184-189
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• 2002

Collision free task planning for dual-arm robot which perform many subtasks in a common work space can be achieved in two steps : path planning and trajectory planning. Path planning finds the order of tasks for each robot to minimize path lengths as well as to avoid collision with static obstacles. A trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position or reduce speed at the middle of its path to avoid collision with the other robot.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.474-477
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• 2005

In tactical theater, it is crucial to detect ground moving targets and to locate them precisely. This problem can be resolved by using SAR (Synthetic Aperture Radar) sensors providing GMTI (Ground Moving Target Indication) capability. In general, to implement a robust GMTI sensor is not simple because of the strong competitions between target signals and clutter signals on the ground, and low speed of moving targets. Contrary to the case that a delay canceller is mostly suitable for ground surveillance radars, DPCA (Displaced Phase Centered Antenna) or STAP (Space Time Adaptive Processing) techniques have been adapted for GMT! function of modem airborne radars. In this paper, anew scheme of DPCA using two passive antennas with vertical separation is proposed, which also provides good clutter cancellation performance. The proposed scheme enables us to scan straight ahead of the carrying platform that is impossible with typical DPCA configuration. Simulations using various conditions have been performed to validate the proposed scheme, and the results are acceptable.

• Journal of Navigation and Port Research
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• v.40 no.2
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• pp.51-56
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• 2016

Expressways mean the primary arterial highways with a high level of efficiency and safety. However, Gyeongbu and Namhae expressways connected with Busan ports are showing travel time delay by increased traffic including the medium/large-sized vehicles of about 20% compared to those of about 13% regardless of the peak periods. This study, thus, intends to analyze lane traffic characteristics in the basic 8-lane segments of the above-mentioned expressways, compute the planning and buffer times based on travel time reliability, find the lane speed showing a higher correlation with planning time between the lane speeds in the basic 8-lane segments, and finally suggest a correlation model for predicting the planning time in expressways.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1080-1084
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• 2007

Many different methods for sound source localization have been developed. Most of them mainly depend on time delay of arrival (TDOA) or on empirical or analytic head related transfer functions (HRTFs). In real implementation, since the direct path between a source and a sensor is interrupted by obstacles as like a head or body of robot, it has to be considered the number of sensors as well as their positions. Therefore, in this paper, we present the methods, which are included sensor position problem, to localize the sound source with 4 microphones to cover the 3D space. Those are modified two-step TDOA methods. Our conclusion is that the different method has to be applied in case to be different microphone position on real robot platform.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.3
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• pp.136-141
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• 2007

In this paper, a new simple control method for active power filter which can realized the complete compensation of the harmonic currents is proposed. In the proposed scheme, a compensating current reference generator employing resonance model implemented by a DSP(Digital Signal Processor) is introduced. Deadbeat control is employed to control the active power filter. The switching pulse width based SVM(Space Vector Modulation) is adopted so that the current of active power filter is been exactly equal to its reference at the next sampling instant. To compensate the computation delay of digital controller, the prediction of current is achieved by the current observer with deadbeat response.