• IE interfaces
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• v.16 no.2
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• pp.185-194
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• 2003

This paper deals with a realistic production scheduling under a make-to-order production environment. The practical case is studied on the transformer winding process in the 'H' company. The transformer winding is a process that rolls a coil that is coated with an electric insulation material in order to generate the required voltage using the voltage fluctuation. This process occupies an important position among the production processes in the transformer manufacturing company. And this process is composed of parallel machines with different performances according to the voltage capacity and winding type. In this paper, we propose a practical heuristic algorithm for production scheduling to satisfy the customer’s due date under a make-to-order production environment. Also, we implement the production scheduling system based on the proposed heuristic algorithm. Consequently, the proposed heuristic algorithm and the implemented production scheduling system are currently working in the transformer production factory of the ‘H’ company.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.1-9
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• 2010

In this paper, the novel architecture of Intra-prediction & DCTQ hardware, which can process for the Full HD image($1980{\times}1088$@30fps) in realtime, is proposed. The cycle optimization method for the overall cycle of prediction, transform, scaling, descaling, and reconstruction is proposed. To reduce the cycle in the $4{\times}4$ prediction, the quantization process is performed during the prediction cycle and pre-selection of 2 modes among the 9 modes is performed to reduce the hardware area. To reduce the hardware of $16{\times}16$ and $8{\times}8$ prediction, the sharing logic between 2 prediction is utilized. The proposed architecture can process the 30frame/sec of full HD image in 108 MHz clock and operate 425 cycle for one macroblock.

• Journal of Broadcast Engineering
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• v.16 no.2
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• pp.216-225
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• 2011

Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies have been preparing for stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting with a heterogeneous video codec system, where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, is considered in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service based on the heterogeneous dual codec systems. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of the left and right bitstreams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter obtained from the proposed optimization scheme. Besides, we consider a condition on maintaining quality difference between the left and right images around a desired level in the optimization in order to mitigate negative effects on human visual system. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm independently in terms of the increase in PSNR by 2.02%, the decrease in the average absolute quality difference by 77.6% and the reduction in the variance of the quality difference by 74.38%.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.548-554
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• 2001

A GA(Genetic Algorithm) based 3D-PTV technique has been developed. The measurement system consists of three CCD cameras, Ar-ion laser, an image grabber and a host computer. The fundamental of the developed technique was based on that one-to-one correspondence is found between two tracer particles selected at two different image frames taking advantage of combinatorial optimization of the genetic algorithm. The fitness function controlling reproductive success in the genetic algorithm was expressed by a kind of continuum theory on the sparsely distributed particles in space. In order to verify the capability of the constructed measurement system, a performance test was made using the LES data set of an impinging jet. The developed 3D-PTV system was applied to the measurement of flow characteristics of the wake of a circular cylinder.

• Korean Journal of Optics and Photonics
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• v.14 no.2
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• pp.200-207
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• 2003

In this paper we present a new method of measuring the relative distance of two point objects in three-dimensional space by using phase-shifting digital holography. In our system the reference beam of a spherical wave is used instead of a plane wave. The system is computer simulated and built on an optical table for experiments. It is shown from computer simulations and experiments that the relative distance can be measured without the exact information on the reference beam used in the hologram record. It is shown from experiments that the relative distance between two point objects separated by 0.5 cm in the distance of about 300 cm from the CCD can be measured with an error less than 10％.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1359-1367
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• 2000

A new coherent detection scheme with data based channel estimation (DBCE) for CDMA/BP(staggered burst pilot in parallel) channel structure is proposed. Because the pilot burst initiates DBCE operation periodically it is shown to be remarkably stable to Gaussian noise and Doppler shift with proper parameter settings. In our own system parameter setting, there is a negligible loss(0.068 dB) in $E_{b}/N_{o}$ by the introduction of the burst pilot. When compared with an ideal coherent detection, the required $E_{b}/N_{o}$ on Doppler shift corresponding to the speed of 160Km/H is degraded less that 2.0 dB. the burst pilot can be implemented without complexity even though some extra correlators are needed for DBCE. This improvement is superior to the previously coherent CDMA detectors with external or internal pilot.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1470-1476
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• 2020

This paper describes a design of a lightweight security system-on-chip (SoC) suitable for the implementation of security protocols for IoT and mobile devices. The security SoC using Cortex-M0 as a CPU integrates hardware crypto engines including an elliptic curve cryptography (ECC) core, a SHA3 hash core, an ARIA-AES block cipher core and a true random number generator (TRNG) core. The ECC core was designed to support twenty elliptic curves over both prime field and binary field defined in the SEC2, and was based on a word-based Montgomery multiplier in which the partial product generations/additions and modular reductions are processed in a sub-pipelining manner. The H/W-S/W co-operation for elliptic curve digital signature algorithm (EC-DSA) protocol was demonstrated by implementing the security SoC on a Cyclone-5 FPGA device. The security SoC, synthesized with a 65-nm CMOS cell library, occupies 193,312 gate equivalents (GEs) and 84 kbytes of RAM.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.435-442
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• 2002

본 연구에서는 사장교의 제어기법 개발을 위한 구조물로 제공되는 벤치마크(benchmark) 사장교에 대해 복합제어 기법을 적용하였다. 이 벤치마크 문제에서는 2003년 완공 예정으로 미국 Missouri 주에 건설 중인 Cape Girardeau 교를 대상 구조물로 고려하였다. Cape Girardeau 교는 New Madrid 지진구역에 위치하고, Mississippi 강을 횡단하는 주요 교량이라는 점 때문에 설계단계에서부터 내진 문제에 대하여 자세하게 고려되었다. 상세 설계도면을 기반으로 하여 교량의 전체적인 거동 특성을 정확하게 나타낼 수 있는 3차원 모델이 만들어졌고, 사장교의 제어 성능에 관련된 평가 기준이 수립되었다. 본 연구에서 사용한 복합제어 기법이란 지진하중으로 인해 구조물에 발생되는 하중을 줄이기 위한 수동제어 기법과 상판변위와 같은 구조물의 응답을 추가적으로 제어하기 위한 능동제어 기법이 결합된 제어방법이다. 수동제어 장치로는 현재 일반적으로 많이 사용되고 있는 납고무받침(lead rubber bearing)을 사용하였다. 능동제어 방법에는 $H_2$/LQG 제어 알고리듬(algorithm)을 사용하였다. 수치해석 결과 제안방법의 성능은 수동제어 방법에 비해 매우 효과적이며, 능동제어 방법에 비해서는 좀더 좋은 제어성능을 나타내었다. 또한, 복합제어 방법은 수동제어 부분 때문에 능동제어 방법에 비해 좀더 신뢰할 수 있는 제어 방법이다. 따라서 제안된 제어방법은 지진하중을 받는 사장교의 제어를 위해 효과적으로 사용될 수 있다.

• Journal of computational fluids engineering
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• v.2 no.1
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• pp.1-7
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• 1997

A FA-FD hybrid method, developed for solving three-dimensional incompressible Navier-Stokes equations, is applied to calculate three-dimensional laminar flows through a square duct with a 90° bend. The method discretizes the convective terms in the primary flow direction with 3rd-order upwind finite-differences and the convective and diffusive terms in the transverse directions with the two-dimensional finite analytic method. The non-staggered grid system is used and the pressure-velocity coupling is achieved by a global iteration procedure based on the PISO algorithm. Detailed comparisons between the computed solutions and the available experimental data are given mainly for the velocity distributions at cross-sections in a 90° bend of a square duct with both fully developed and developing entry flows. Although the computational result shows generally a good agreement with the experimental data, there are some significant discrepancies underlining the necessity of more accurate numerical methods as well as reliable experimental data for their validation.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.1091-1105
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• 2012

In this paper, we analyzed statistical characteristics and complexity of HEVC encoder as a leading research of acceleration, optimization and parallelization. Computational complexity of the HEVC encoder is approximately twice the compression performance compared to H.264/AVC. But, the increase of encoder complexity remains a problem to be solved in the future. Before performing the research on acceleration, optimization and parallelization to reduce high complexity of HEVC encoder, we measure the complexity each module for HEVC encoder using it's reference software HM 7.1. We also measured the predicted complexity of fast HEVC encoder software, used in real applications, using HM 7.1 applying fast encoding method. The complexity is measured in terms of the operating cycle of the encoder software under the common test sequences and conditions in the Windows PC environment. In addition, we analyze statistical characteristics of HEVC encoder software according to encoding structures and limitation using coded bitstreams.