• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.3B
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• pp.280-287
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• 2001

본 논문에서는 기존의 LCD MW를 이용한 각 다중화 시스템에서 인접한 수직방향 MW 사이의 crosstalk를 제거하기 위하여 MW의 뒷단에 수직방향으로 주기적으로 서로 다른 초점 길이를 갖는 이중초점 렌즈를 삽입하여 인접한 MW의 기준빔이 서로 다른 공간에 기록되게 함으로써 기준빔의 전자적 제어뿐만 아니라 고밀도의 정보저장 및 복원이 가능한 새로운 공간-각 다중화 기법을 제안하고 이에 대한 광학 실험을 통해 구현가능성을 제시하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.65-73
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• 2011

In this paper, we present a novel digital multifocusing approach using adaptive region-based histogram equalization for the multiple color-filter aperture (MCA) system with insufficient amount of incoming light. From the image acquired by the MCA system, we can estimate the depth information of objects at different distances by measuring the amount of misalignment among the RGB color planes. The estimated depth information is used to obtain multifocused images together with the process of the region-of-interests (ROIs) classification, registration, and fusion. However, the MCA system results in the low-exposure problem because of the limited size of the apertures. For overcoming this problem, we propose adaptive region-based histogram equalization. Based on the experimental results, the proposed algorithm is proved to be able to obtain in-focused images under the low light level environment.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.34-41
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• 2017

As an alternative of the existing honeycomb shock absorbing device, the new approach on shock absorbing design using the extrusion of hyper-viscoelastic material such as silicon rubber is studied in this paper. The strain energy and stress-strain characteristic of viscoelastic material at extrusion process through the metered orifice has a similarity with the honeycomb core for maximizing shock absorbing capability. And in order to evaluate the design feasibility of this device and to understand the shock absorbing mechanism of energy transformation, finite element analysis and quasi-static compression test of the multi-stage extrusion shock absorber are examined in this paper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.915-918
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• 2009

다중 네트워크 인터페이스 단말과 멀티 네트워크 환경간의 통신을 위한 네트워크 구조에 관한 기존 연구는 GLL, A-MAC처럼 멀티네트워크 자원관리에 초점을 둔 프로토콜 연구가 대부분이며 이 프로토콜들은 2.5 계층, 즉, 네트워크 계층과 데이터 링크 계층 사이에 위치하여 응용을 위해서 다중 인터페이스 중 하나의 인터페이스를 선택할 수 있는 기능을 제공한다. 따라서 기존 연구에 초점은 기존 통신 프로토콜 및 인터넷 구조의 변화를 최소화 할 수 있으나 단말내의 응용이 다중 네트워크 인터페이스를 효율적으로 사용할 수 있는 기술은 아니다. 본 연구에서는 기존 통신 프로토콜 및 인터넷 구조에서 단말이 다중 네트워크 인터페이스 사용 시 발생하는 계층별 문제점 및 IETF MIF WG 표준화 동향을 분석한다. 특히 응용 계층이 멀티 네트워크 인터페이스 기반의 멀티 연결을 지원하지 못하는 문제점, 전송 계층에서의 다중 연결 시 발생하는 문제점, 네트워크 계층에서 다중 인터페이스별로 할당된 IP 주소에 대한 처리문제, 다중 인터페이스 라우팅 문제, Split DNS 문제, 응용별 서비스 요구에 적응적인 인터페이스 선택 방법에 관한 문제를 정의하고 이를 해결하기 위한 연구 방향을 제시한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.706-709
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• 2005

A hybrid focus method with multiple laser slits has been newly proposed and it is based on the integration of DFD and DFF Rough depth information is estimated using DFD equipped with multiple laser slits, and then DFF is applied to only each specific depth range using the depth information resulting from DFD. The proposed hybrid method gives more accurate results than DFD and DFF, and faster measurement than DFF. Its performance has been verified through experiments of calibration blocks with sharp depth discontinuity.

• The Journal of Information Technology
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• v.7 no.3
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• pp.119-126
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• 2004

In multicast traffic, an input can request to connect to up to a certain number of outputs. This reviews the multicast nonblocking multistage interconnection networks. In a multistage interconnection network each stage consists of crossbars of the same size. This paper focuses on the three-stage network and its recursive extensions. Not only will this article bring the literature upto date, but it also will provide some fresh viewpoints to either clarify or simplify some issues.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.1-6
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• 2002

We propose a novel fractal-space multiplexing holographic memory system using moving window and double-focusing lens, which can eliminate crosstalk due to two neighboring moving window rows in the vertical direction of the conventional moving window holographic memory system, and demonstrated its feasibility through optical experiments.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.111-118
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• 2006

A hybrid focus method with multiple laser slits is newly proposed for the measurement of surface morphology with depth discontinuity, and it is based on the integration of DFB and DFF. Rough depth information is estimated through calibration tables which are constructed by DFD with multiple laser slits, and then DFF is applied to only each specific depth range using the rough depth information resulting from DFD. The proposed hybrid method gives more accurate results than DFD and DFF, and faster measurement than DFF in the vicinity of depth discontinuity Its performance is verified through experiments of calibration blocks with sharp depth discontinuity.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2
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• pp.52-57
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• 2001

The passive ranging estimation techniques using a focused beamformer have been studied under the water. It is well known that the passive ranging estimation method using a focused beamformer is excellently evaluated. Among these, the passive ranging sonar is known to have a good performance under low signal-to-noise. ratio. However, its performance is degraded in multi-source environments. In this paper, we proposed the technique using dual focused beamformers to estimate the range. And when the sampling frequency is low, it is very difficult to steer the focused beam to the desired direction, as a result of this, the low performance occurs because of a distorted beam pattern. In this paper, we study the effect of sampling rate on passive ranging by using focused beamformer. And we verified the performance of the proposed method via computer simulation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.4 s.304
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• pp.87-94
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• 2005

3D image mosaicking is useful for 3D visualization of the roadside scene of urban area by projecting 2D images to the 3D planes. When a sequence of images are filmed from a side-looking video camera passing long distance areas, the ghost effect in which same objects appear repeatively occurs. To suppress such ghost effect, the long distance range areas are detected by using the distance between the image frame and the 3D coordinate of tracked optical flows. The ghost effects are suppressed by projecting the part of image frames onto 3D multiple planes utilizing vectors passing the focal point of frames and a virtual focal point. The virtual focal point is calculated by utilizing the first and last frames of the long distance range areas. We demonstrate algorithm that creates efficient 3D Panoramic mosaics without the ghost effect at the long distance area.