• Journal of Advanced Marine Engineering and Technology
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• 제40권3호
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• pp.191-197
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• 2016

선박이 고출력화, 대형화 됨에 따라 추진축의 강성은 증가한 반면에 선체는 고장력 후판을 사용하므로 이전의 선체보다 훨씬 더 쉽게 변형되는 실정이다. 흘수변화에 따른 선체변형은 축계를 구성하는 각각의 베어링 옵셋 및 반력에 연쇄적인 영향을 미치게 된다. 이는 기존의 선박보다 더욱 정교한 축계정렬이 요구됨을 의미한다. 본 연구에서는 최근 친환경 고효율 선박으로 등장한 5만 DWT급 석유화학제품운반선을 대상으로 선박의 흘수 변화에 따른 선미부 구조해석을 실시하고 구조해석으로부터 얻어진 축계의 상대변위를 이용하여 축계정렬 해석을 수행하였다. 구조해석은 선박의 통상 운항조건에서 최대 흘수 변화를 고려한 2개 조건에서 수행하였다. 이를 바탕으로 선체변형에 따른 베어링 옵셋 변화가 축계정렬에 미치는 영향을 검토하였다.

• 한국인쇄학회지
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• 제25권2호
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• pp.15-28
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• 2007

For the color offset printing, it starts with input of data. The past days, drum scanner or flat scanner used to input of data, but now it changes gradually into using of digital camera because digital camera become popular. The high quality digital camera saves as a data(RAW format), sRGB which have built in digital camera, or Adobe RGB format. sRGB of ICC(International Color Consortium) profile is a standard color gamut of digital camera. Distribution of color gamut in sRGB is less than Adobe RGB have a distribution in ICC profile. sRGB also can not be expressed in some specific part, because distribution of color gamut in sRGB is not able to cover all parts in ICC Profile of international standards CMYK. It is more popular to use Adobe RGB than sRGB to do high quality offset printing and software basis color setting in Europe and Japan. In spite of this data basis, there is a difficulty of doing color correction between the color proofing prints and the final prints. To see how the software color setting effects to RGB data, this thesis will use Gretag Macbeth ColorChecker 24 patch which has the most general natural color chart to compare sRGB and Adobe RGB to check the differences of color changes. It will use the several factors that came out from the process of making ICC Profile to figure out the optimum In-house profile. It also compares the differences of using matt paper and glossy paper to do best quality color proof offset printing, and how the Rendering Intent effects the proof print.

• IEIE Transactions on Smart Processing and Computing
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• 제3권1호
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• pp.1-9
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• 2014

This paper proposes a low-latency Sample Adaptive Offset filter (SAO) architecture and its Single Instruction Multiple Data (SIMD) optimization scheme to achieve fast High Efficiency Video Coding (HEVC) decoding in a multi-core environment. According to the HEVC standard and its Test Model (HM), SAO operation is performed only at the picture level. Most realtime decoders, however, execute their sub-modules on a Coding Tree Unit (CTU) basis to reduce the latency and memory bandwidth. The proposed low-latency SAO architecture has the following advantages over picture-based SAO: 1) significantly less memory requirements, and 2) low-latency property enabling efficient pipelined multi-core decoding. In addition, SIMD optimization of SAO filtering can reduce the SAO filtering time significantly. The simulation results showed that the proposed low-latency SAO architecture with significantly less memory usage, produces a similar decoding time as a picture-based SAO in single-core decoding. Furthermore, the SIMD optimization scheme reduces the SAO filtering time by approximately 509% and increases the total decoding speed by approximately 7% compared to the existing look-up table approach of HM.

• Radiation Oncology Journal
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• 제23권3호
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• pp.176-185
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• 2005

목적: 환자별 강도변조방사선치료 정도관리(IMRT QA) 중 필름 선량계를 임상에 적용하고, 필름 등선량중심점 치우침 교정 최적화법을 개발하였다. 최적화 후 필름 선량계에 대한 정량적 허용기준도 제시하고자 하였다. 대상 및 방법: IMRT 치료를 시행하기로 한 14명의 두경부종양 환자에서 필름 선량계를 시행하고, 가장 큰 계통적 오차 요인인 필름 등선량중심점 치우침 교정 최적화법을 고안하여 적용하였다. 결과: 필름 선량계의 필름 등선량중심점 치우침 교정 최적화법은 local minimum을 구하는 방식으로 고안하였으며, 환자에게 적용 시 조정값은 2 mm를 보인 2명을 제외하고 12명에서 1 mm로 나타났다. 필름 등선량중심점 치우침 교정 최적화 전후로 선량오차 결과를 산출하였으며, 최적화 전후의 절대 평균 선량오차의 평균은 각각 $2.36\%,\;1.56\%$, 점선량오차가 $5\%$ 이상인 지점의 비율은 평균은 각각 $9.67\%,\;2.88\%$로서 최적화 후 선량오차가 현저히 감소하였다. 최적화 후 절단 저선량 영역을 설정하였으며, 최적화 후 $5\%$ 이상의 점선량오차 지점 수 $10\%$ 미만, 절대평균 선량오차 $3\%$ 미만의 필름 선량계를 위한 정량적 허용 기준을 제시하였다. 결론: 본 연구에서 개발한 최적화법은 필름 선량계의 치우침 교정에 매우 유효하며, 최적화 후 제시된 정량적 허용 기준은 환자별 IMRT QA에 유용하게 사용될 수 있을 것으로 기대된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.157.2-157
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• 2001

This paper describes the synergism of Artificial Neural Network and Fuzzy Logic based approach to improve the reliability of transformer differential protection, the conventional transformer differential protection commonly used a harmonic restraint principle to prevent a tripping from inrush current during initial transformer´s energization but such a principle can not performs the best optimization on tripping time. Furthermore, in some cases there may be false operation such as during CT saturation, high DC offset or harmonic containing in the line. Therefore an artificial neural network and fuzzy logic has been proposed to improve reliability of the transformer protection relay. By using EMTP-ATP the power transformer is modeled, all currents flowing ...

• 한국CDE학회논문집
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• 제6권3호
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• pp.169-173
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• 2001

Presented in this paper is a CPO tool-path linking procedure optimizing technological objectives, such as dealing with islands (positive and negative) and minimizing tool retractions, drilling holes and slotting. Main features of the proposed algorithm are as follows; 1) a data structure, called a 'TPE-net', is devised to provide information on the parent/child relationships among the tool-path-elements, 2) the number of tool retractions is minimized by a 'tool-path-element linking algorithm'fading a tour through the TPE-net, and 3) the number of drilling holes is minimized by making use of the concept of the 'free space'.

• ETRI Journal
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• 제34권6호
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• pp.946-949
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• 2012

We present the optimization of a birefringence-enhanced-waveguide (BWG)-based polarization beam splitter (PBS) in a Mach-Zehnder interferometer (MZI) configuration and analyze the structure-dependent or polarization-dependent phase difference, using a delay-line MZI (DL-MZI). We fabricate the DL-MZI using silica-based planar lightwave circuit technology and, using the DL-MZI, demonstrate the ability to optimize a PBS by measuring the birefringence of the BWG and structure-dependent phase offset.

• 대한조선학회논문집
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• 제46권1호
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• pp.87-95
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• 2009

The applicability of optimization techniques for hull surface fitting has been important in the ship design process. In this research, the Genetic Algorithm has been used as a searching technique for solving surface fitting problem and minimizing errors between B-spline surface and the ship's offset data. The encoded design variables are the location of the vertex points and parametric values. The sufficient accuracy in surface fitting implies not only various techniques for computer-aided design, but also the future production design.

• 한국인쇄학회지
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• 제24권2호
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• pp.69-78
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• 2006

Proofing is one of the inspection operations of printing and can be considered a process control step. The three main kinds of proofs are press proofs, photomechanical proofs, and digital proofs. Photomechanical and digital proofs are also generally refered to as "off-press" proofs. Off-press color proofs are more economical than press proofs. Digital proofs offer fast production time along with a much lower cost per page. Hard-copy digital proofs can be output using thermal transfer printers, ink jet printers, and color laser copiers, as well as dye sublimation and electrophotographic technology. Ink jet method is commonly using because of the reasonal price. But ink jet system is difficult to reproduce an exact color proof. This research was carried out for the purpose of optimization of ink jet color proofing, using two kinds of ink jet printers with 6 colors (C, M, Y, K, mC, mM) and 4 colors (C, M, Y, K) system.

• 대한기계학회논문집A
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• 제27권4호
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• pp.485-490
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• 2003

RP(Rapid Prototyping) has been used in the various industrial applications. This paper presents the optimization techniques fur fabricated 3D model design using RP machine for the medical field. Once the original brain model data are obtained from 2D slices of MRI/CT machine, the data can be modeled as an optimal ellipse. The objective of this study includes optimization of fabrication time and surface roughness using the adaptive slicing method. It can reduce fabrication time without losing surface roughness quality by accumulating the slices with variable thickness. According to the parameter tuning and synthesis of its effect, more suitable parameter values can be obtained by enhanced 3D brain model fabrication. Therefore, accurate 3D brain model fabricated by RP machine can enable a surgeon to perform pre-operation. to make a decision for the operation sequence and to perceive the 3D positions in prototype, before delicate operation of actual surgery.