• Title/Summary/Keyword: aberrations

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Design of a Catadioptric System with Corrected Color Aberration and Flat Petzval Curvature Using a Graphically Symmetric Method

  • Lim, Tae-Yeon;Park, Sung-Chan
    • Current Optics and Photonics
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    • v.2 no.4
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    • pp.324-331
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    • 2018
  • This paper describes a symmetric method for determining a combination of element power and optical material to design a catadioptric system with corrected color aberration and flat Petzval curvature. To graphically obtain the solutions, a glass chart containing the Abbe number, the refractive index, and the optical power, which are closely related to these aberrations, is suggested. First, we recompose an optical system as a doublet of the specific lens and an equivalent single lens, and then locate both lenses on lines that are symmetric to each other on a glass chart, through changing the lens parameters effectively. Utilizing this method, an achromatic catadioptric system with flat Petzval curvature is obtained.

High-Resolution Microarrays for Mapping Promoter Binding sites and Copy Number Variation in the Human Genome

  • Albert Thomas
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2006.02a
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    • pp.125-126
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    • 2006
  • NimbleGen has developed strategies to use its high-density oligonucleotide microarray platform (385,000 probes per array) to map both promoter binding sites and copy number variation at very high-resolution in the human genome. Here we describe a genome-wide map of active promoters determined by experimentally locating the sites of transcription imitation complex binding throughout the human genome using microarrays combined with chromatin immunoprecipitation. This map defines 10,567 active promoters corresponding to 6,763 known genes and at least 1,196 un-annotated transcriptional units. Microarray-based comparative genomic hybridisation (CGH) is animportant research tool for investigating chromosomal aberrations frequently associated with complex diseases such as cancer, neuropsychiatric disorders, and congenital developmental disorders. NimbleGen array CGH is an ultra-high resolution (0.5-50 Kb) oligo array platform that can be used to detect amplifications and deletions and map the associated breakpoints on the whole-genome level or with custom fine-tiling arrays. For whole-genome array CGH, probes are tiled through genic and intergenic regions with a median probe spacing of 6 Kb, which provides a comprehensive, unbiased analysis of the genome.

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A Study on Stability Improvement of High Energy Laser Beam Wavefront Correction System

  • Jung, Jongkyu;Lee, Sooman
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.2
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    • pp.1-7
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    • 2018
  • The adaptive optics for compensating for optical wavefront distortion due to atmospheric turbulence has recently been used in systems that improve beam quality by eliminating the aberrations of high power laser beam wavefront. However, unseen-mode, which can not be measured in the wavefront sensor, increases the instability of the laser beam wavefront compensator on the adaptive optics system. As a method for improving such instability, a mathematical method for limiting the number of singular values is used when generating the command matrix involved in generation of the drive command of the wavefront compensator. In the past, however, we have relied solely on experimental methods to determine the limiting range of the singular values. In this paper, we propose a criterion for determining the limiting range of the singular values using the driving characteristics and the correlation technique of the wavefront compensator's actuators and have proved its performance experimentally.

Chromosome Variation in Suspension Cells Derived from Cultured Immature Embryo of Triticum spp. (밀(Triticum spp.)의 미성숙배로부터의 유도한 현탁 배양세포에서의 염색체 변이)

  • 방재욱
    • Journal of Plant Biology
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    • v.33 no.3
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    • pp.189-196
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    • 1990
  • Suspension cell lines have been newly established from the calli derived from the immuature embryo culture of hexapolid (Triticum aestivum var. sicco), tetrapolid (T. durum) and diploid (T. tauchii or Aegilops squarrosa) wheat species. The chromosomal variation in suspension cultured cell lines was examined and old cell line, C82d, established from T. aestivum var. copain was also used. New method using 1-bromonaphthalene for metaphase rapping of suspension cells was developed. Variation in chromosome number was observed among all the suspension lines. Cells with doubled chromosome number and deleted chromosome were also observed. Extensive structural changes in chromosome were found in C82d line. Chromosome aberrations showed loss of chromosome arms and chromosome segment. The mean chromosome number in suspension cells of T. aestivum var. sicco was 40, in C82d line 33, in T. durum 28 and in T. tauchii 14. The stability of chromosome in suspension cells of diploid and tetrapolid wheats was higher than that of hexaploid wheat.

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Optical system design fur head mounted display using diffractive optical elements (회절광학소자를 이용한 Head Mounted Display용 광학계 설계)

  • 박성찬
    • Korean Journal of Optics and Photonics
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    • v.12 no.6
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    • pp.512-518
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    • 2001
  • In this paper, the geometrical properties of the optical system for Head Mounted Display (HMD) were investigated. Also, this work deals with the concept for an optical system design bated on Diffractive Optical Elements (DOE). In designing the optical system for HMD, it is considered that the optical system should have compact, high performance, and comfortable properties while user sees the picture. In order to satisfy these requirements, we applied DOE and aspheric surfaces to the lens so that correction of color and monochromatic aberrations could be obtained. Also, the design and evaluation for the optical system were carried out using the generalized model of the human eye. Finally, it was expected to fulfill all the requirements of an HMD system.

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Wavefront Sensitivity Analysis Using Global Wavefront Aberration in an Unobscured Optical System

  • Joo, Won Don
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.228-235
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    • 2012
  • It is very important to analyze effectively the tolerance of an optical system with high resolution as the projection lens of photolithography or as the objective lens of a microscope. We would like to find an effective assembly structure and compensators to correct aberrations through global wavefront sensitivity analysis using Zernike polynomial expansion from the field and pupil coordinates rather than from only pupil coordinates. In this paper, we introduce global wavefront coefficients by small perturbations of the optical system, and analyze the optical performance with these coefficients. From this analysis, it is possible to see how we can enlarge the tolerance through the proper assembly structure and compensators.

Studies on Cytochemical Toxicities of Chlorophenols to the Rat (Chlorophenol류의 세포화학적 독성에 관한 연구)

  • Chung, Yong
    • YAKHAK HOEJI
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    • v.22 no.4
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    • pp.175-192
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    • 1978
  • Chlorination of the polluted water may produce odoriferous and objectionable-tasting chlorophenols which are hazardous to health. These studies were undertaken to investigate the hazardous effects of chlorophenols to the rat. 1. The chlorophenols such as o-chlorophenol and 2,6-dichlorophenol inhibited rat growth and caused increment of the ratio between liver weight and body weight. 2. The hemoglobin content, hamatocrit ratio and A/G of rat blood were decreased by chlorophenols administration. The activities of alkaline phosphatase, lactic dehydrogenase (LDH) and glutamate oxaloacetate transaminase (GOT) in serum as well as in liver were increased provisonally and decreased after one or two weeks adminstration. 3. The liver mitochondrial respiration ($QO_{2}$) was inhibited by chlorophenols treatment in in-vivo and in-vitro test. 4. The liver microsomal cytochrome P-450 was decreased by chlorophenols administration 5. Liver tissue was degenerated with congestion, atrophy, swelling, vacuolation, dilation of rough endoplasmic reticulum and denature of mitochondrial particle with swelling, and cristal destruction by chlorophenols adminstration. 6. After one and two weeks of adminstration of chlorophenols to rat, the aberrations of bone marrow chromosome and inhibition of its mitosis were observed respectively.

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Characteristics of Point-diffraction Interferometer for certification of high-precision optical system (고정밀 광학계 측정을 위한 점회절 간섭계의 특성 연구)

  • Lee, Kyeong-Hee;Choi, Young-Wook
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.138-139
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    • 2007
  • The use of conventional Twyman and Fizeau interferometers inevitably fails in testing high precision optics because of errors always existing in reference elements producing the reference wavefront. Therefore it is necessary to apply to this task the interferometers of a radically new type, which are able to produce perfect reference wavefront with the help of light diffraction by a small obstacle or pinhole. In this paper new theoretical approaches and schematics of point diffraction interferometers are considered in detail with paying attention to constructive reliability. Such interferometers do not use reference optical surfaces and readily provide adequate estimation of errors and aberrations value of 0.01 wavelengths.

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Shaded-Mask Filtering for Extended Depth-of-Field Microscopy

  • Escobar, Isabel;Saavedra, Genaro;Martinez-Corral, Manuel;Calatayud, Arnau;Doblas, Ana
    • Journal of information and communication convergence engineering
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    • v.11 no.2
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    • pp.139-146
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    • 2013
  • This paper proposes a new spatial filtering approach for increasing the depth-of-field (DOF) of imaging systems, which is very useful for obtaining sharp images for a wide range of axial positions of the object. Many different techniques have been reported to increase the depth of field. However the main advantage in our method is its simplicity, since we propose the use of purely absorbing beam-shaping elements, which allows a high focal depth with a minimum modification of the optical architecture. In the filter design, we have used the analogy between the axial behavior of a system with spherical aberration and the transverse impulse response of a 1D defocused system. This allowed us the design of a ring-shaded filter. Finally, experimental verification of the theoretical statements is also provided.