• Title/Summary/Keyword: Projection Principle

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HYBRID MONOTONE PROJECTION ALGORITHMS FOR ASYMPTOTICALLY QUASI-PSEUDOCONTRACTIVE MAPPINGS

  • Wu, Changqun;Cho, Sun-Young
    • East Asian mathematical journal
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    • v.25 no.4
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    • pp.415-423
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    • 2009
  • In this paper, we consider the hybrid monotone projection algorithm for asymptotically quasi-pseudocontractive mappings. A strong convergence theorem is established in the framework of Hilbert spaces. Our results mainly improve the corresponding results announced by [H. Zhou, Demiclosedness principle with applications for asymptotically pseudo-contractions in Hilbert spaces, Nonlinear Anal. 70 (2009) 3140-3145] and also include Kim and Xu [T.H. Kim, H.K. Xu, Strong convergence of modified Mann iterations for asymptotically nonexpansive mappings and semigroups, Nonlinear Anal. 64 (2006) 1140-1152; Convergence of the modified Mann's iteration method for asymptotically strict pseudo-contractions, Nonlinear Anal. 68 (2008) 2828-2836] as special cases.

Range Simulation on Spin Effort of golfball (골프공 스핀효과에 따른 비거리 시뮬레이션)

  • Han, Tae-Jong;Kim, Yong-Sun;Lee, Soon-Ho
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.117-131
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    • 2003
  • This study simulated the range of golf ball with different projection angles using a drive swing condition. For the simulation purpose, the differential equation of dynamics was induced by using Bernoulli's principle and average back spin frequency, instant velocity, and dimple of golf ball from amateur group, professional group, and Tiger Woods were chosen as the initial condition. The study result indicated that lift coefficient($C_{lift}$) relative to drag coefficient ($C_d$), 0.3 of differential equation was applied differently in terms of back spin Sequency, and when $C_{lift}$ was 0.4 for amateur, 0.5 for professional, and 0.7 for Tiger Woods the projection ranges of ball were closely matched with initial condition. With selected $C_{lift}$ and back spin frequency of initial condition, the ranges with different projection angle was measured as 193m ($13-17^{\circ}$) for amateur, 240m ($9-13^{\circ}$), professional and 273m ($9^{\circ}$)Tiger Woods, respectively. For the range in terms of back spin frequency and projection angle, the amateur group indicated relatively high spin frequency (70 RPS) and showed the maximal range (195m) with $13^{\circ}$ of projection angle. The tendency of longer range with higher projection angle was also found under the different conditions of spin frequency in this group. The professional group showed their maximal range (245m) with conditions of 60RPS of spin frequency and $9^{\circ}$ of projection angle. Their range was decreased dramatically when the spin frequency was reduced to 40-50 RPS. For Tiger Woods, the maximal range was found with 40RPS of spin frequency and the range was decreased notably when the spin frequency was above 40RPS.

In-camera VFX implementation study using short-throw projector (focused on low-cost solution)

  • Li, Penghui;Kim, Ki-Hong;Lee, David-Junesok
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.2
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    • pp.10-16
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    • 2022
  • As an important part of virtual production, In-camera VFX is the process of shooting actual objects and virtual three-dimensional backgrounds in real-time through computer graphics technology and display technology, and obtaining the final film. In the In-camera VFX process, there are currently only two types of medium used to undertake background imaging, LED wall and chroma key screen. Among them, the In-camera VFX based on LED wall realizes background imaging through LED display technology. Although the imaging quality is guaranteed, the high cost of LED wall increases the cost of virtual production. The In-camera VFX based on chroma key screen, the background imaging is realized by real-time keying technology. Although the price is low, due to the limitation of real-time keying technology and lighting conditions, the usability of the final picture is not high. The short-throw projection technology can compress the projection distance to within 1 meter and get a relatively large picture, which solves the problem of traditional projection technology that must leaving a certain space between screen and the projector, and its price is relatively cheap compared to the LED wall. Therefore, in the In-camera VFX process, short-throw projection technology can be tried to project backgrounds. This paper will analyze the principle of short-throw projection technology and the existing In-camera VFX solutions, and through the comparison experiments, propose a low-cost solution that uses short-throw projectors to project virtual backgrounds and realize the In-camera VFX process.

An Efficient Algorithm for 3-D Range Measurement using Disparity of Stereoscopic Camera (스테레오 카메라의 양안 시차를 이용한 거리 계측의 고속 연산 알고리즘)

  • 김재한
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1163-1168
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    • 2001
  • The ranging systems measure range data in three-dimensional coordinate from target surface. These non-contact remote ranging systems is widely used in various automation applications, including military equipment, construction field, navigation, inspection, assembly, and robot vision. The active ranging systems using time of flight technique or light pattern illumination technique are complex and expensive, the passive systems based on stereo or focusing principle are time-consuming. The proposed algorithm, that is based on cross correlation of projection profile of vertical edge, provides advantages of fast and simple operation in the range acquisition. The results of experiment show the effectiveness of the proposed algorithm.

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Development of Non-contact Image Measuring Technique for Evaluating Micro-relief (미세주름 측정을 위한 비접촉식 영상측정기술의 발전)

  • Kim, Nam-Soo;Kim, Yong-Min
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.3 s.52
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    • pp.253-257
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    • 2005
  • Assurance of the objectivity and reproducibility is a major key point in wrinkle measurement used for evaluating the degree of skin aging. The measurement of relief is quickly converted to a non-contact method, of which tools or instruments do not come in contact with skin directly, to minimize the artificial effects which influence the shape or depth of the relief. Here, we showed how wrinkle measurement techniques have been changed briefly and compared PRIMOS and replica method in the point of view of measurement principle and features, the former is non-contact fringe projection tool and the latter is contact type of the method.

A Case Study on Investigation Stability of Cut Slope in Road (국도와 인접한 절토부 사면안전성 대책에 관한 연구)

  • 이승호;임재승;정태영;신희순;이은동
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.45-52
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    • 2003
  • Construction and extension of road by industrialization are increasing. According to this, construction of large cutting slope is increasing. Therefore, many methods for slope stability by this are applied. Failure happens according to dip and dip direction of slope. It is actuality that is connoting unstable element. This slope include coaly shale. Stability of slope failure this study takes place by road extension running examination for stability property calculate. Use this and examined stability about stereographic projection and wedge failure. Apply suitable reinforcement countermeasure about unstable cutting slope and analyzed stability. Wish to consider effective and robust processing plan of great principle earth and sand side securing stability. Hereafter with these data, is going to utilize in reinforcement and failure prevention.

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The Principle and Applications of Moire Phenomenon (모아레 현상의 원리와 응용)

  • 박윤창
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.6
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    • pp.25-31
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    • 2000
  • "모아레(MOIRE)"란 말은 처음으로 프랑스인들에 의해 불려진 단어로써 고대 중국에서 수입된 비단 위에 새겨진 물결무늬(wave pattern)를 일컫는 말이다. 이렇게 불리어지던 모아레는 요즈음에 들어서서 두 개 이상의 주기적인 패턴(periodic pattern)이 겹쳐질 때 만들어지는 간섭무늬 (interference fringe)를 지칭하는 말로써 다양한 분야에서 매우 광범위하게 사용되어 지고 있다.(중략)

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Fresnel computer-generated holograms for 3-D display of Real objects

  • Yatagai, Toyohiko;Sando, Yusuke;Itoh, Masahide
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.437-440
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    • 2003
  • Computer-generated holograms of real existing are synthesized by using a series of projection images of an incoherently illuminated object. The principle of computer tomography is applied to obtain the 3-D Fourier spectrum of the object. A Fresnel hologram is calculated directly from the 3-D Fourier spectrum. Experimental results with simulation are presented and some optical properties of reconstructed images are discussed.

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Algorithms and Programs for Optimization of Large-Scale Dynamic System (대형동적 시스템의 최적화 앨고리즘 및 프로그램 개발에 관한 연구)

  • 양흥석;박영문;김건중
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.32 no.4
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    • pp.121-127
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    • 1983
  • In this paper an efficient algorithm for Pontriagin's maximum principle is developed. Fletcher-Powell method is adopted as optimization technique which shows fast and stable convergence characteristics. Terminal constraints are alse considered by using Hestens' algorithm and penalty function method together. Control variable inequality constraints are also considered by using Gradient Projection technique combined with Flectcher-Powell method. Test experiment shows good and reliable results.

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Three-dimensional Machine Vision System based on moire Interferometry for the Ball Shape Inspection of Micro BGA Packages (마이크로 BGA 패키지의 볼 형상 시각검사를 위한 모아레 간섭계 기반 3차원 머신 비젼 시스템)

  • Kim, Min-Young
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.1
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    • pp.81-87
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    • 2012
  • This paper focuses on three-dimensional measurement system of micro balls on micro Ball-Grid-Array(BGA) packages in-line. Most of visual inspection system still suffers from sophisticate reflection characteristics of micro balls. For accurate shape measurement of them, a specially designed visual sensor system is proposed under the sensing principle of phase shifting moire interferometry. The system consists of a pattern projection system with four projection subsystems and an imaging system. In the projection system, four subsystems have spatially different projection directions to make target objects experience the pattern illuminations with different incident directions. For the phase shifting, each grating pattern of subsystem is regularly moved by PZT actuator. To remove specular noise and shadow area of BGA balls efficiently, a compact multiple-pattern projection and imaging system is implemented and tested. Especially, a sensor fusion algorithm to integrate four information sets, acquired from multiple projections, into one is proposed with the basis of Bayesian sensor fusion theory. To see how the proposed system works, a series of experiments is performed and the results are analyzed in detail.