• Title/Summary/Keyword: Linear blending

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Real-Time Nonlinear Lens-Flare Rendering Method Based on Look-Up Table (룩업테이블 기반 실시간 비선형 렌즈플레어 렌더링 방법)

  • Jo, Sunghun;Jeong, Yuna;Lee, Sungkil
    • Journal of KIISE
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    • v.44 no.3
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    • pp.253-260
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    • 2017
  • In computer graphics, high-quality lens flares have been generated using costly offline rendering. A recent matrix-based approximation has enabled generation of high-quality lens flares suitable for real-time applications, but its quality degrades due to the lack of nonlinear patterns of lens flares. This paper introduces a method for high-quality lens-flare rendering, which includes blending of both nonlinear as well as linear patterns. The nonlinear patterns are pre-rendered or photo-graphically captured offline and stored in a look-up table. The online stage reads only the pattern by looking up the table using a light angle, hence making its performance drop negligible while greatly improving the quality.

Crystallization Characteristics of Metallocene Low Density Polyethylene/Low Density Polyethylene Blends (메탈로센 선형 저밀도 폴리에틸렌/선형 저밀도 폴리에틸렌 블렌드의 결정화 거동)

  • 김경룡;한정우;강호종
    • Polymer(Korea)
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    • v.25 no.6
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    • pp.840-847
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    • 2001
  • The crystallization characteristics of metallocene linear low density polyethylene (m-LLDPE)/linear low density polyethylene (LLDPE) blends were investigated. The effect of blending on the induction time for crystallization, spherulites growth rate, and maximum size of spherulites was mainly considered in this study. The formation of separate crystal which is well known crystallization behavior in LLDPE/LDPE blend was not found in m-LLDPE/LLDPE blends. The blending m-LLDPE to LLDPE caused the dramatic decrease in the induction time of m-LLDPE/LLDPE blends but it seems that the blend composition shows less effect on the induction time. Lower branching number in m-LLDPE resulted in the increasing of spherulites growth rate and the maximum size of spherulites is depend upon both the induction time and spherulites growth rate of LLDPE component affected by m-LLDPE.

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Effect of Metallocene-catalyzed Polyethylene on the Rheological and Mechanical Properties of Poly(phenylene sulfide)/Polyethylene Blends

  • Lee, Bo-Sun;Chun, Byoung-Chul;Chung, Yong-Chan
    • Fibers and Polymers
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    • v.5 no.2
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    • pp.145-150
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    • 2004
  • Blends of poly(phenylene sulfide) (PPS) and polyethylene, either linear low density polyethylene (LLDPE) or metallocene-catalyzed polyethylene (MPE), that were prepared by melt blending, were investigated. From the rheological properties as determined by capillary rheometry, the melt viscosity of both PPS/LLDPE and PPS/MPE blends was low when PE was in dispersed phase, but high melt viscosity was observed for both blends with PPS in dispersed phase. Significant differences depending on the composition were found in the mechanical properties such as percent elongation at break and notched Izod impact strength. In addition, dispersed phase morphology of the blends was analyzed by a scanning electron microscope (SEM), together with brief discussion about the difference between them.

Image Enhancement Based on Local Histogram Specification (로컬 히스토그램 명세화에 기반한 화질 개선)

  • Khusanov, Ulugbek;Lee, Chang-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.1
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    • pp.18-23
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    • 2013
  • In this paper we propose an image enhancement technique based on histogram specification method over local overlapping regions referred as Local Histogram Specification. First, both reference and original images are splitted into local regions that each overlaps half of its adjacent regions and general histogram specification method is used between corresponding local regions of reference and original image. However it produces noticeable boundary effects. Linear weighted image blending method is used to reduce this effect in order to make seamless image and we also proposed new technique dealing with over-enhanced contrast areas. We satisfied with our experimental results that showed better enhancement accuracy and less noise amplifications compared to other well-known image enhancement methods. We conclude that the proposed method is well suited for motion detection systems as a responsible part to overcome sudden illumination changes.

A study on the Performance of Hybrid Normal Mapping Techniques for Real-time Rendering

  • ZhengRan Liu;KiHong Kim;YuanZi Sang
    • International journal of advanced smart convergence
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    • v.12 no.4
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    • pp.361-369
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    • 2023
  • Achieving realistic visual quality while maintaining optimal real-time rendering performance is a major challenge in evolving computer graphics and interactive 3D applications. Normal mapping, as a core technology in 3D, has matured through continuous optimization and iteration. Hybrid normal mapping as a new mapping model has also made significant progress and has been applied in the 3D asset production pipeline. This study comprehensively explores the hybrid normal techniques, analyzing Linear Blending, Overlay Blending, Whiteout Blending, UDN Blending, and Reoriented Normal Mapping, and focuses on how the various hybrid normal techniques can be used to achieve rendering performance and visual fidelity. performance and visual fidelity. Under the consideration of computational efficiency, visual coherence, and adaptability in different 3D production scenes, we design comparative experiments to explore the optimal solutions of the hybrid normal techniques by analyzing and researching the code, the performance of different hybrid normal mapping in the engine, and analyzing and comparing the data. The purpose of the research and summary of the hybrid normal technology is to find out the most suitable choice for the mainstream workflow based on the objective reality. Provide an understanding of the hybrid normal mapping technique, so that practitioners can choose how to apply different hybrid normal techniques to the corresponding projects. The purpose of our research and summary of mixed normal technology is to find the most suitable choice for mainstream workflows based on objective reality. We summarized the hybrid normal mapping technology and experimentally obtained the advantages and disadvantages of different technologies, so that practitioners can choose to apply different hybrid normal mapping technologies to corresponding projects in a reasonable manner.

Combustion Characteristics for Co-firing of Biomass (Walnut Shell) (바이오매스(호두껍질) 혼소에 대한 연소 특성에 관한 연구)

  • Kim, Jin-Ho;Lee, Byoung-Hwa;Sh, Lkhagvadorj;Kim, Sang-In;Jeon, Chung-Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.1
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    • pp.53-59
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    • 2015
  • Combustion characteristics for co-firing of biomass (Walnut Shell) as blending fuel in coal fired boiler have investigated using thermogravimetric analyser (TGA) and drop tube reactor (DTR). The results show that devolatilization and char combustion for WS occurs at lower temperature than those of existing coals and has lower activation energy value, which is resulting in higher reactivity. When the WS is blended with coal, TGA results show linear profiles depending on blending ratio for each fuel. However, DTR results exist the non-additive phenomena for blending of WS. As blending ratio of WS increase, the UBC decrease at BBR 5%, but the UBC rather increase from BBR 10% due to oxygen deficiency formed from rapid combustion of WS. This paper propose that fuel lean condition by oxygen rich lead to higher blending ratio of biomass by solving the oxygen deficiency condition.

Non-linear Preferences on Bioethanol in South Korea (국내 바이오에탄올에 대한 비선형적 선호에 관한 연구)

  • Bae, Jeong Hwan
    • Environmental and Resource Economics Review
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    • v.23 no.3
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    • pp.515-551
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    • 2014
  • Recently, there has been a debate as to whether bioethanol should replace some portion of gasoline for fuels in South Korea, as energy security as well as climate change issues are rising as a significant national agenda. However, a considerable amount of subsidy will be required to compensate for the higher price of bioethanol-blended gasoline. In this context, government subsidy will obtain justification only when the positive social gains from consuming bioethanol for fuels can exceed the negative social costs. Through a nation-wide choice experimental survey, we examine if South Koreans have a positive value as well as non-linear preferences on substituting bioethanol for gasoline. The results reveal that the willingness to pay for purely domestic bioethanol-blended gasoline within 10% is about 52 KRW; Koreans have concave preferences on the blending ratio of bioethanol to gasoline. The turning point of the blending ratio of bioethanol was 6.5%. Also, we found inverse U-shaped curve between income and bioethanol choice probability and the turning point of the income was calculated as 250~299million KRW. Politically conservative propensity advocates uses of bioethanol blended gasoline, but awareness on bioethanol or more weights on environmental conservation have significantly negative effects on the choice of bioethanol. However, the design of the survey questionnaire is incompatible with the RFS of Korea and assumes orthogonality among the following four interrelated attributes: (i) domestic or offshore procurement of feedstocks in the case of domestic production, (ii) domestic production or import of bioethanol, (iii) the blending ratios, and (iv) the retail price increases. In addition, the results of model estimation and of model selection test are not definite. Hence, the results in this study should not be directly applied to the design of the specifics of the Korean RFS. Hence, the results in this study require cautions in applying to the design of the Korean RFS policy.

Development of a Simulation Program to Predict the Performance of the Multi-grade Lubricant before Blending Base Oil with Additives (기유와 첨가제 혼합 전 다등급 윤활유의 성능 예측 시뮬레이션 프로그램 개발)

  • Chun, Sang-Myung
    • Tribology and Lubricants
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    • v.28 no.2
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    • pp.47-55
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    • 2012
  • Generally, to product multi-grade oil like engine oil, a sort of mineral base oil is mixed with a fundamental additive package liquid and a polymer liquid as viscosity index improver in order to improve the lubricating property of base oil. That is, engine oil is the mixture of more than two fluids. Specially, a polymeric type liquid cannot be seen as the linear viscosity like Newtonian fluids. In this research, by using the governing equation describing non-Newtonian hydrodynamic lubrication related with the mixture of incompressible fluids based on the principle of continuum mechanics, it will be compared the bearing performance between the mixture of each liquid to be blended and multi-grade engine oil as a single fluid in a high speed hydrodynamic journal bearing. Further, it is to be found the way estimating the performance of the blended multi-grade engine lubricant in a journal bearing in advance before blending by using the physical properties of mineral base oil, fundamental additive liquid and polymer liquid of viscosity index improver. So, it can be reduced the number of trial and error to get the wanted lubricant by selecting the proper volume fraction of each liquid to satisfy the expected performance and estimating in advance the performance of various multi-grade oils before blending. Therefore, it can be shorten the developing time and saved the developing cost.

Linear Free Energy Relationship on the Chemical Shift of Imidoyl Proton in N-benzylideneaniline Derivatives by PMR Spectrometry (核磁氣 共鳴分光法에 義한 N-Benzylideneaniline 誘導體중 Imidoyl Proton 의 Chemical Shift 에 미치는 自由에너지 關係)

  • Nack Do Sung;Cheon Kyu Park;Moon kyu Park;Ki Sung Kwon;Kim, Tae Rin
    • Journal of the Korean Chemical Society
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    • v.29 no.3
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    • pp.277-282
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    • 1985
  • The effects of linear free energy relationship (LFER) on the imidoyl proton (H${\alpha}$)-substituent chemical shift (SCS) in case of varying para-substituted C-phenyl group in N-benzylideneaniline derivatives were studied. The H${\alpha}$-SCS values and LFER parameters such as ${\sigma}$,${\sigma}^+$, ${\sigma}_I$,${\sigma}_R, F and R were applied to the Hammett, Okamoto-Brown, and Taft, Swain-Lupton's dual substituents parameter (DSP) equations. The results were: (1) the blending coefficient values, ${\lambda}$ = 2.8∼3.2, it's means that the resonance effect (R) was larger than inductive effect (I) and field effect (F), and (2) the values of percent resonance and percent field effects were %R = 66.6 and %F = 33.4, respectively, yielding the ratio of resonance effect (R) to field effect (F) of 2 : 1.

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