• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.2
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• pp.1-9
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• 1980

A voltage synthesizing channel selection circuit was designed to improve on the conventional vol tape synthesizer which has been memorized each charnel's tuning vol cage itself. In the course of this study, tuning voltage was calculated by channel number entered from 10 keys. Then this circuit has tie function of direct access channel selection and rear display of channel number for the whole range of UHF and VHF, Attention was also given to realize the fine tuning by searching each commended channel, and the sequential selection by using 2keys, and the flash of channel indicator in case of inactive station.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.100-103
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• 2011

In the present work, a numerical study of fluid flow and heat transfer on the concave surface with impinging jet has been performed by solving three-dimensional Reynods-averaged Naver-Stokes(RANS) equations. The constant temperature condition was applied to the concave impingement surface. The inclination angle of jet nozzle and the distance between jet nozzles are chosen as design variables under equivalent mass flow rate of working fluid into cooling channel, and area averaged Nusselt number on concave impingement surface is set as the objective function. Thirteen training points are obtained by Latin Hypercube sampling method, and the PEA model is constructed by using the objective function values at the trainging points. And, the sequential quadratic programming is used to search for the optimal paint from the PBA model. Through the optimization, the optimal shape shows improved heat transfer rate as compared to the reference geometry.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.697-701
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• 2010

The numbers of digital video cameras are fast increased. Accordingly, digital video data management is becoming more important. Efficient storing method and fast browsing method still remains to be one of significant issue. In this paper, an optimized data storing process without losing information and an organized appearance features indexing method are proposed. Also, the data removing policy could be used to reduce large amount of space and it facilitates fast sequential search. The appearance features index constructs key information of moving objects to answer queries about what people are doing, particularly when, where and who they move. The evaluation results showed better performance in the transfer time and the saving in storage space.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.812-815
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• 2009

This paper discusses a searching method for special markers attached with persons in a surveillance video stream. The marker is a small plate with infrared LEDs, which is called a spatiotemporal marker because it shows a 2-D sequential pattern synchronized with video frames. The search is based on the motion vectors which is the same as one in video compression. The experiments using prototype markers show that the proposed method is practical. Though the method is applicable to a video stream independently, it can decrease total computation cost if motion vector analyses of a video compression and the proposed method is unified.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.121-127
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• 2006

It has become inevitable to search for alternative fuels due to severe energy crisis these days. Use of alternative fuels, which are typically of lower quality, tends to increase environmental pollution, including formation of nitrogen oxides (NOx). In this paper performance of vacuum residue has been investigated experimentally as well as numerically in typical operating conditions of a furnace. Heat release reaction is modeled as sequential steps of devolatilization, simplified gas phase reaction and char oxidation as that for pulverized coal. Thermal and fuel NOx are predicted by conditional estimation of elementary reaction rates and are compared against measured experimental data. On the overall reasonable agreement is achieved for spatial distributions of major species, temperature and NOx for all test cases.

• Communications for Statistical Applications and Methods
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• v.21 no.2
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• pp.161-168
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• 2014

In mixture experiments with process variables, we consider the case that some of process variables are either uncontrollable or hard to control, which are called noise variables. Given the such mixture experimental data with process variables, first we study how to search for candidate models. Good candidate models are screened by the sequential variables selection method and checking the residual plots for the validity of the model assumption. Two methods, which use numerical optimization methods proposed by Derringer and Suich (1980) and minimization of the weighted expected loss, are proposed to find a cost-effective robust optimal condition in which the performance of the mean as well as the variance of the response for each of the candidate models is well-behaved under the cost restriction of the mixture. The proposed methods are illustrated with the well known fish patties texture example described by Cornell (2002).

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.193-195
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• 2004

저렴한 비용으로 기존의 클라이언트 서버 시스템을 대체할 수 있는 P2P 시스템에서 서로 공유하고자 하는 파일의 리스트를 얼마나 빠르고 효과적으로 검색하느냐는 시스템 성능을 좌우하는 중요한 항목 중 하나이다. 그러나 기존의 P2P 시스템에서의 검색 기법들은 목적 파일들에 대한 검색 시간의 단축과 키워드 검색이라는 두 가지 설계 목표 중 어느 한 쪽에만 치중하여 설계됨으로써 종합적인 검색 기능이 요구되는 실제 시스템에 적용되기에는 매우 불완전하다. 본 논문에서는 P2P 시스템에 참여하여 파일을 공유하고자 하는 노드들의 모든 공유파일 목록을 하나의 전역 디렉토리로 구성하고 이를 이진 값의 순서대로 저장함으로써 높은 검색 속도로 키워드 검색 기능을 제공하는 다중 노드 전역 디렉토리 기반 색인 순차 검색 기법을 제안한다. 제안된 기법은 높은 겅색 속도와 키워드 검색을 지원함으로써 P2P 시스템의 검색 속도 성능 개선과 사용자 편의성을 제공한다.

• The KSFM Journal of Fluid Machinery
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• v.12 no.4
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• pp.44-53
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• 2009

Numerical design optimization of a fan-shaped hole for film-cooling has been carried out to improve film-cooling effectiveness by combining a three-dimensional Reynolds-averaged Navier-Stokes analysis with the radial basis neural network method, a well known surrogate modeling technique for optimization. The injection angle of hole, lateral expansion angle of hole and ratio of length-to-diameter of the hole are chosen as design variables and spatially averaged film-cooling effectiveness is considered as an objective function which is to be maximized. Twenty training points are obtained by Latin Hypercube sampling for three design variables. Sequential quadratic programming is used to search for the optimal point from the constructed surrogate. The film-cooling effectiveness has been successfully improved by the optimization with increased value of all design variables as compared to the reference geometry.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.520-527
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• 2016

A new dual-loop digital delay-locked loop (DLL) using a hybrid (binary + sequential) search algorithm is presented to achieve both wide-range operation and high delay resolution. A new phase-interpolation range selector (PIRS) and a variable successive approximation register (VSAR) algorithm are adopted to resolve the boundary switching and harmonic locking problems of conventional digital DLLs. The proposed digital DLL, implemented in a $0.18-{\mu}m$ CMOS process, occupies an active area of $0.19mm^2$ and operates over a wide frequency range of 0.15-1.5 GHz. The DLL dissipates a power of 11.3 mW from a 1.8 V supply at 1 GHz. The measured peak-to-peak output clock jitter is 24 ps (effective pk-pk jitter = 16.5 ps) with an input clock jitter of 7.5 ps at 1.5 GHz. The delay resolution is only 2.2 ps.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.2
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• pp.1-7
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• 1984

This paper is concerned with an optimum design study of containerships in preliminary stage by applying economic criteria. The Net Present Value Index (NPVI) and the Required Freight Rate(RFR) are used as measures of merit. Hooke & Jeeves direct search method and External Penalty Function method of Sequential Unconstrained Minimization Techniques(SUMT) are used for solving constrained nonlinear optimization problem. Sensitivity analysis is carried out to investigate the effect on the optimum solution due to change of values in some parameters such as crane capacity, load factor, oil price, ship speed and the ratio between loaded FEU and TEU.