• Title/Summary/Keyword: engineering optimization

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Optimum Design Based on Sequential Design of Experiments and Artificial Neural Network for Enhancing Occupant Head Protection in B-Pillar Trim (센터 필라트림의 FMH 충격성능 향상을 위한 순차적 실험계획법과 인공신경망 기반의 최적설계)

  • Lee, Jung Hwan;Suh, Myung Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.11
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    • pp.1397-1405
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    • 2013
  • The optimal rib pattern design of B-pillar trim considering occupant head protection can be determined by two methods. One is the conventional approximate optimization method that uses the statistical design of experiments (DOE) and response surface method (RSM). Generally, approximated optimum results are obtained through the iterative process by trial-and-error. The quality of results strongly depends on the factors and levels assigned by a designer. The other is a methodology derived from previous work by the authors, called the sequential design of experiments (SDOE), to reduce the trial-and-error procedure and to find an appropriate condition for using artificial neural network (ANN) systematically. An appropriate condition is determined from the iterative process based on the analysis of means. With this new technique and ANN, it is possible to find an optimum design accurately and efficiently.

A Digital Elevation Analysis : Sparially Distributed Flow Apportioning Algorithm (수치 고도 분석 : 분포형 흐름 분배 알고리즘)

  • Kim, Sang-Hyeon;Kim, Gyeong-Hyeon;Jeong, Seon-Hui
    • Journal of Korea Water Resources Association
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    • v.34 no.3
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    • pp.241-251
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    • 2001
  • A flow determination algorithm is proposed for the distributed hydrologic model. The advantages of a single flow direction scheme and multiple flow direction schemes are selectively considered to address the drawbacks of existing algorithms. A spatially varied flow apportioning factor is introduced in order to accommodate the accumulated area from upslope cells. The channel initiation threshold area(CIT) concept is expanded and integrated into the spatially distributed flow apportioning algorithm in order to delineate a realistic channel network. An application of a field example suggests that the linearly distributed flow apportioning scheme provides some advantages over existing approaches, such as the relaxation of over-dissipation problems near channel cells, the connectivity feature of river cells, the continuity of saturated areas and the negligence of the optimization of few parameters in existing algorithms. The effects of grid sizes are explored spatially as well as statistically.

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Optimizing the fermentation condition of low salted squid jeotgal by lactic acid bacteria with enhanced antioxidant activity

  • Akther, Fahima;Le, Bao;Chung, Gyuhwa;Yang, Seung Hwan
    • Journal of Applied Biological Chemistry
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    • v.60 no.4
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    • pp.391-402
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    • 2017
  • Lactic acid bacteria (LAB) are widely used as starter culture in food fermentation due to their harmless entity and health beneficial properties along with the ability to change texture, aroma, flavor and acidity of food products. In this study, five different LAB (FB003, FB058, FB077, FB081, and FB111) isolated from different Korean traditional fermented foods, assigned to Lactobacillus plantarum, Pediococcus pentosaceus, Weissella viridescens, Lactobacillus sakei, and Leuconostoc mesenteroides, respectively, on the basis of their physiological properties and 16S rRNA sequence analysis, to use as fermentation starter and check their ability to fasten the ripening time as well as the overall optimization in the fermentation condition. To check their suitability as starters, their safety, acid and bile tolerance, NaCl and temperature resistance, susceptibility to common antibiotics, and antimicrobial activities were determined. Squid jeotgal samples were prepared by adding $10^8CFU/g$ of each strain in different samples, which were then kept for fermentation at $4^{\circ}C$ and checked for their antioxidant activities at 0, 7, 15, and 21-day intervals. The samples fermented with FB003 and FB077 displayed the highest antioxidant activity. This study revealed two effective starter cultures (FB003, FB077) for squid jeotgal fermentation, which presented increased functionalities. The results of this study will lead to the development of novel industrial-scale production avenues for jeotgal preparation, and offer new insights into the prevention and control of chronic diseases.

The Optimization of Offset Printing Process for High Quality Color Reproduction (1) - Prepress and proofing - (고품질 색재현을 위한 오프셋 인쇄공정의 최적화에 관한 연구(I) - 프리프레스와 교정인쇄를 중심으로 -)

  • Kim, Sung-Su;Kang, Sang-Hoon
    • Journal of the Korean Graphic Arts Communication Society
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    • v.25 no.2
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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.

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The Optimization of Offset Printing Process for High Quality Color Reproduction (II) - Platemaking and Presswork - (고품질 색재현을 위한 오프셋 인쇄공정의 최적화에 관한 연구(II) - 제판과 인쇄공정을 중심으로 -)

  • Kim, Sung-Su;Kang, Sang-Hoon
    • Journal of the Korean Graphic Arts Communication Society
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    • v.25 no.2
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    • pp.69-84
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    • 2007
  • Producing printing plate is essential progress to do offset printing. In this Film-less period, the more PS plate becomes extinct, the more the age of the Plate-Making of Exposure declines the place to stand. To do offset printing, the CTP (Computer to Plate) is taking a place of PS plate that covers speed, quality and economical problems. The biggest advantage of using CTP is that laser directly goes to the plate, thus there are no dust from the Plate-Making of Exposure. It is also theoretically able to print $200lpi{\sim}300lpi$ as well as print 1751pi, because it has over 2400dpi resolution. The high quality printing could be available inside of the country, if printing machine keeps the optimum condition in offset printing. The CTP has many advantages, however there is a difficulty for the operators to preserve the equipment. The actual circumstance is that they cannot make a decision about how many dots need to be generated, and also it is necessary to know how to establish the setup at RIP on CTP to make the optimum condition output. If offset printing machine keeps the optimum condition, it would be able to print up to high quality printing however it is hard to comment what is the optimum condition for the printing machine. Anyone could say easy subjectively that machine is in the optimum condition, however it is objectively hard to estimate by number. In this research GATF / Plate Test target used to analyze the image and to make numerical value of the optimum condition of the CTP. It also used GATF / The sheep fed test printing 5.0 to know the density of the color representation, dot gain and gray balance for the optimum condition of the print machine. The purpose of this research is to represent the ISO 12647-2 which is the international standard with domestic printing equipments.

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Minimizing Energy Consumption in Scheduling of Dependent Tasks using Genetic Algorithm in Computational Grid

  • Kaiwartya, Omprakash;Prakash, Shiv;Abdullah, Abdul Hanan;Hassan, Ahmed Nazar
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.8
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    • pp.2821-2839
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    • 2015
  • Energy consumption by large computing systems has become an important research theme not only because the sources of energy are depleting fast but also due to the environmental concern. Computational grid is a huge distributed computing platform for the applications that require high end computing resources and consume enormous energy to facilitate execution of jobs. The organizations which are offering services for high end computation, are more cautious about energy consumption and taking utmost steps for saving energy. Therefore, this paper proposes a scheduling technique for Minimizing Energy consumption using Adapted Genetic Algorithm (MiE-AGA) for dependent tasks in Computational Grid (CG). In MiE-AGA, fitness function formulation for energy consumption has been mathematically formulated. An adapted genetic algorithm has been developed for minimizing energy consumption with appropriate modifications in each components of original genetic algorithm such as representation of chromosome, crossover, mutation and inversion operations. Pseudo code for MiE-AGA and its components has been developed with appropriate examples. MiE-AGA is simulated using Java based programs integrated with GridSim. Analysis of simulation results in terms of energy consumption, makespan and average utilization of resources clearly reveals that MiE-AGA effectively optimizes energy, makespan and average utilization of resources in CG. Comparative analysis of the optimization performance between MiE-AGA and the state-of-the-arts algorithms: EAMM, HEFT, Min-Min and Max-Min shows the effectiveness of the model.

A Study on the Stress Analysis of Oil Hydraulic Piston Pump with a Swash Plate Type (사판식 유압 피스톤 펌프의 응력해석에 관한 연구)

  • Jeong, Bong-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2424-2429
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    • 2015
  • In an oil hydraulic piston pump, the cylinder block and valve plate in high speed relative sliding motion have the characteristics which should be extremely controlled for the optimization of leakage and friction losses, and pressure-resistance design of them is very important for high pressure performance. But the studies on the stress analysis of those parts have not been performed briskly. Therefore, in this paper, the stress and displacement distributions of the cylinder block and valve plate in the oil hydraulic piston pump with a swash plate type are discussed through the static stress analysis using CATIA V5. The stress and displacement of the cylinder block are more influenced by the axial pressure than by the radial pressure, and are larger by approximately 66% and 30%, respectively. The results show that a review of the material and shape of the valve plate is required.

Fast Intermode Decision for Scalable Video Coding using Statistical Hypothesis Testing (스케일러블 비디오 부호화에서 통계적 가설 검증 기법을 이용한 고속 화면간 모드 결정)

  • Lee, Bum-Shik;Hahm, Sang-Jin;Kim, Byung-Sun;Lee, Keun-Sik;Park, Keun-Soo;Kim, Mun-Churl
    • Journal of Broadcast Engineering
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    • v.12 no.3
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    • pp.250-265
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    • 2007
  • In this paper, a fast intermode decision scheme is introduced by efficiently performing the mode decision using statistical hypothesis testing for hierarchical B-picture coding of SVC, in which much computational power is expensed for combined variable block sizes and hierarchical B-pictures. The hypothesis testing in the proposed method is performed on $16{\times}16\;and\;8{\times}8$ blocks to have early termination for RD computation of all possible modes. The early termination in intermode decision is performed by comparing the pixel values of current blocks and corresponding motion-compensated blocks. The proposed scheme exhibits effective early termination behavior in intermode decision and leads to a significant reduction up to 69% in computational complexity with slight increment in bit amounts. The degradation of visual quality turns out to be negligible in terms of PSNR values.

Methodologies to Improve Emotional Image Qualities by Optimizing Technological Image Quality Metrics (기술적인 화질 지표 조절양 최적화를 통한 감성 화질 향상 방안)

  • You, Jae-Hee
    • Science of Emotion and Sensibility
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    • v.20 no.1
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    • pp.57-66
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    • 2017
  • Emotional image quality optimization methodologies are investigated using technological image quality controls based on the eye tests of various image samples. The images are evaluated based on various contrast, lightness and saturation image quality metric tone curves. The order of importance to image quality enhancements is contrast, saturation and brightness. The slopes of emotional image qualities with respect to technical image quality metric changes are found to be composed of mathematical function modelling with nearly zero, intermediate and maximum slope regions in general, which can reflect well known log and saturated as well as conventional reverse U shape natures. Image quality improvements are analyzed not only with just single but also with multiple image quality metrics. To ease the unified image quality metric analysis and control, a new function is presented to utilize both the newly found and conventional emotional image quality behaviors. It is found that the overall image quality enhancement can be realized only in a few limited cases of multiple image quality metric controls. It is also found that the kinds of image quality enhancement methodologies are not strongly dependent on image contents (genre).

Synthesis of Single Crystal Diamond by Variation of Deposition Pressure by HFCVD (HFCVD에 의한 증착압력 변화에 따른 Single Crystal Diamond 합성)

  • Kim, Min Su;Bae, Mun Ki;Kim, Seong-Woo;Kim, Tae Gyu
    • Journal of the Korean Society for Heat Treatment
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    • v.33 no.1
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    • pp.20-24
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    • 2020
  • Single crystal diamonds are in great demand in such fields as mechanical, electronic applications and optoelectronics. Large area single crystal diamonds are attracting attention in future industries for mass production and low cost. In this study, hot filament CVD (HFCVD) is used to grow large area single crystal diamond. However, the growth rate of large area single crystal diamond using HFCVD is known to be very low. The goal of this study is to use single crystal diamond substrates in HFCVD with methane-hydrogen gas mixtures to increase the growth rate of single crystal diamond and to optimize the conditions by analysing the effects of deposition conditions for high quality crystallinity. The deposition pressure, the ratio of CH4/H2 gas, the substrate temperature and the distance between the filament and the substrate were optimized. The sample used a 4×4 (mm2) size single crystal diamond substrate (100), the CH4/H2 gas ratio was fixed at 5%, the substrate temperature was synthesized to about 1000℃. At this time, the deposition pressure was changed to three types of 50, 75, 85 Torr and deposited. Finally, optimization was investigated under pressure conditions to analyse the growth rate and quality of single crystal diamond.