• Title/Summary/Keyword: CGH.

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Fast Computation Algorithm of Fresnel Holograms Using Recursive Addition Method (반복 가산 기법을 이용한 Fresnel 홀로그램의 고속 계산 알고리듬)

  • Choi, Hyun-Jun;Seo, Young-Ho;Kim, Dong-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.5C
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    • pp.386-394
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    • 2008
  • For digital holographic video system, it is important to generate digital hologram as fast as possible. This paper proposed a fixed-point method and fast generation method that can calculate the Fresnel hologram using operation of whole-coordinate recursive addition. To compute the digital hologram, 3D object is assumed to be a collection of depth-map point generated using a PC. Our algorithm can compute a phase on a hologram by recursive addition with fixed-point format at a high speed. When we operated this algorithm on a personal computer, we could maximally compute digital hologram about 70% faster than conventional method and about 30% faster than of [3]'s method.

3-D DISPLAY USING COMPUTER-GENERATED BINARY HOLOGRAMS

  • Yoshinori-Kajiki;Masaaki-Okamoto;Koji-Yamasaki;Eiji-Shimizu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1999.06a
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    • pp.227-232
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    • 1999
  • We have been making researches on 3-D displays using computer-generated holograms(CGHs). Our CGHs are binary Fresnel holograms that reconstruct point light sources and are recorded by using high resolution laser printers (image setters). We use an image setter with a resolution of 5080 dots per inch. It is possible to reconstruct CGHs with light-emitting points. As the resolution of the image setter is not so high, it is better to use a spherical wave as a reference beam. We considered the recordable points objects are restricted by the low resolution, and proposed the multiplex type hologram to reduce the number of point objects recorded in the unit area of the CGH. We proposed a method to make computer-generated color hologram which could reconstruct color point light sources, by combining RGB color filters with the stripe CGHs corresponding to each color. We considered two kinds of gradation method on our binary CGHs. In this paper, we propose a multiple reconstruction method for improving the narrow viewing field.

A Study on the Angular Characteristics of Photopolymer-based Hologram Recording and Reproducing Light

  • Kwang-pyo, Hong;Jiwoon, Lee;Lee-hwan, Hwang;Soon-chul, Kwon;Seunghyun, Lee
    • International Journal of Advanced Culture Technology
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    • v.10 no.4
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    • pp.460-469
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    • 2022
  • Increasing interest in the metaverse world these days, interest in realistic content such as 3D displays is growing. In particular, hologram images seen in movies provide viewers with an immersive display that cannot be seen in conventional 2D images. Since the first discovery of holography by Dennis Gabor in 1948, this technology has developed rapidly. Spatially, this beginning of technology like Optical hologram called analog hologram and Digital hologram such as computer-generated hologram (CGH). In analog and digital holograms, a recording angle and a recording wavelength are having important role when reproducing and display hologram. In the hologram, diffraction of light causes by unexpected formed by the synthesis from interference with object and reference light. When recording, the incident light information and mismatched reproduction light reconstruct the hologram in an undesirable direction. Reproduction light that is out of sync with incident light information with initial condition of recording will cause reconstructed image in an undesirable direction. Therefore, we analyze the holographic interference pattern generated by hologram recording in volume holograms using photopolymer and analyze the characteristics that vary depending on the angle of the reproduced light. This is expected to be used as a basic research on various holographic application that may cause as holograms are applied to industries in the future.

Effect of Mulligan SNAGs on Pain, Neck Dysfunction, and Depression in patients with Cervicogenic headache (멀리건 SNAGs 기법이 경추성 두통 환자의 통증, 경부 기능 장애 및 우울증에 미치는 영향)

  • Park, Jae-myoung;Shin, Eui-joo;Hong, Hyun-pyo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.28 no.2
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    • pp.25-34
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    • 2022
  • Background: Cervical headache (CGH) is a common condition that causes serious damage. Mulligan described a sustained natural apophyseal glides (SNAGs) as a manual therapy approach to treat this dysfunction. Although there have been several case studies to evaluate the effectiveness of SNAG, the efficacy of SNAG for cervical headaches is still controversial. Therefore, this study examined the effects of Mulligan's SNAG technique on cervical headache and pain intensity to present basic clinical data. Methods: Thirty-two subjects participated in this study, 16 each in the experimental and control groups. The experimental group applied Mulligan's SNAGs technique and the control group applied the placebo SNAGs technique. Results: Significant differences (p<.05) in the changes in pain, neck disability index (NDI) and Hamilton rating scale for depression (HRSD) were observed between the two groups. Conclusion: The application of Mulligan's SNAG technique to patients with cervical headaches effectively reduced headache, depression, and neck dysfunction. Based on this study, Mulligan's SNAGs technique can be used as an objective research method for additional studies targeting cervical headache patients in the future.

Characterization of growth hormone-like sequence of loach, Misgurnus mizolepis (미꾸라지 성장 호르몬 염기 서열의 특성에 대하여)

  • Kim, Jin-Kyung;Song, Young-Hwan
    • Journal of fish pathology
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    • v.7 no.2
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    • pp.95-103
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    • 1994
  • We have prepared cDNA libray of loach. M. mizolepis in order to isolate cDNA clone of growth hormone gene. Total RNA was isolated from pituitary of loach, and then mRNA was further purified from total RNA by oligo (dT)-coupled magnetic beads. The purified mRNA was used as substrates to prepare cDNA. The resulting cDNA was ligated into the EcoRV/Smal site of pBlueKS+. The ligation mixture have transformed E. coli JM109 strain with electroporator to obtain high yield of transformation efficiency. All the transformants was screened with DIG-labeled Tilapia growth hormone gene by high density colony hybridization. After isolating 10 putative colonies showing the positive signals, secondary colony hybridization and southern hybridization could confirm it as true clones. The nucleotide sequence of one candidate, pCGHI, was compared with 312 bp DNA fragment used as DNA probe and show 52% relative homology to Tilapia growth hormone gene.

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Fast Generation and Reconstruction of Digital Holograms Using a Novel Look-up Table (새로운 룩업테이블을 이용한 3차원 디지털 홀로그램의 고속 합성 및 복원)

  • Kim, Seung-Chul;Kim, Eun-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.3C
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    • pp.255-261
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    • 2008
  • Conventional look-up table(LT) has gained a lot of speed increase in generation of digital holograms for 3D objects, but it has required an enormous memory size of the LT. In this paper, a novel approach to dramatically reduce the size of the conventional LT, still keeping its advantage of fast computational speed is proposed, which is called here a N-LT(novel look-up table) method. In the proposed method, only the fringe patterns of the center points on each image plane are pre-calculated, called elemental fringe patterns and stored in the look-up table. Then, the fringe patterns for other object points on each image plane can be obtained by simply shifting this pre-calculated elemental fringe pattern according to the displaced values from the center to those points and adding them together. Some experimental results revealed that the computational speed and the required memory size of the proposed approach are found to be 48.7 times faster than that of the ray-tracing method and 217 times smaller than that of the conventional LT method, respectively.

Targeting SHCBP1 Inhibits Cell Proliferation in Human Hepatocellular Carcinoma Cells

  • Tao, Han-Chuan;Wang, Hai-Xiao;Dai, Min;Gu, Cheng-Yu;Wang, Qun;Han, Ze-Guang;Cai, Bing
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5645-5650
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    • 2013
  • Src homology 2 domain containing (SHC) is a proto-oncogene which mediates cell proliferation and carcinogenesis in human carcinomas. Here, the SHC SH2-domain binding protein 1 (SHCBP1) was first established to be up-regulated in human hepatocellular carcinoma (HCC) tissues by array-base comparative genome hybridization (aCGH). Meanwhile, we examine and verify it by quantitative real-time PCR and western blot. Our current data show that SHCBP1 was up-regulated in HCC tissues. Overexpression of SHCBP1 could significantly promote HCC cell proliferation, survival and colony formation in HCC cell lines. Furthermore, knockdown of SHCBP1 induced cell cycle delay and suppressed cell proliferation. Furthermore, SHCBP1 could regulate the expression of activate extracellular signal-regulated kinase 1/2 (ERK1/2) and cyclin D1. Together, our findings indicate that SHCBP1 may contribute to human hepatocellular carcinoma by promoting cell proliferation and may serve as a molecular target of cancer therapy.

Fast Generation of 3-D Hologram Fringe Patterns by using the Block Redundancy of 3-D Object Images and the Novel Look-up Table Method (3차원 영상의 블록 중복성 및 N-LUT 기법을 이용한 3차원 홀로그램 프린지 패턴의 고속합성)

  • Kim, Si-Hyung;Koo, Jung-Sik;Kim, Seung-Cheol;Kim, Eun-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2355-2364
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    • 2012
  • Recently, the novel loop-up table(N-LUT) method to solve the tremendous memory problem of the conventional look-up table (LUT) method as well as to increase the generation speed of hologram patterns has been proposed. But, as the resolution of an input 3-D object is enhanced, the number of object points to be calculated for generation of its hologram pattern also increases, which results in a sharp increase of the computation time. Therefore, in this paper, a new approach for fast generation of the hologram pattern of 3-D object images is proposed by using the block redundancy feature of 3-D object images and the N-LUT method. Experimental results show that in the proposed method the number of object points and the overall computation time have been reduced by 43.3 % and 47.9 %, respectively compared to those of the conventional method for the case of the $5{\times}5$ block size. These good experimental results finally confirm the feasibility of the proposed method.

Wavelet-based Electronic Watermarking Algorithm for Digital Holography Interference Patterns (디지털 홀로그래피 간섭패턴을 위한 웨이블릿 기반의 전자적인 워터마킹 알고리듬)

  • Choi, Hyun-Jun;Seo, Young-Ho;Wi, Sung-Min;Yoo, Ji-Sang;Kim, Dong-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.10
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    • pp.1751-1758
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    • 2008
  • Digital holography interference pattern generated by a computer calculation (CGH) is one of the most expensive contents and its usage is being expanded. Thus, it is highly necessary to protect the ownership of digital hologram. In this paper a hologram-domain and a frequency-domain electronic watermarking schemes were proposed. The hologram-domain scheme was only to compare the results to the ones from frequency-domain scheme and the frequence-domain scheme used 2-dimensional against the attaks. Especially the MDWT-domain scheme was very high robustness such that th error ratio at the worst case was only 3%. Thus, we expect that it is used as a good watermarking scheme of digital hologram with high performance.

Genetic Change from Colorectal Carcinoma Patients Using Comparative Genomic Hybridization (비교유전자교잡법을 이용한 대장암환자에서의 유전자변화)

  • Lee, Jae Sik
    • Korean Journal of Clinical Laboratory Science
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    • v.47 no.4
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    • pp.209-215
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    • 2015
  • Colorectal carcinoma is one of the four major cancers in Korea, and it shows the tendency of increase every year due to economic development and changes to western styles. Accordingly, various diagnostic methods are needed and so comparative genomic hybridization (CGH) was performed. Deletion was detected on 5q (10%), 10q (17%), 17p (40%), 18p (23%), 18q (47%), 22q (23%), and higher deletion loci were 18q (12/30, 47%), 17p (12/30, 40%), and 22q (7/30, 23%). Amplification was shown on chromosomes 6pq (10%), 7p (17%), 7q (33%), 8q (13%), 9pq (10%), 12q (17%), 13q (37%), 20p (23%), and 20q (57%) respectively. The highest amplification was detected on chromosomes 20q (17/30, 57%), 13q (11/30, 37%), and 7q (10/30, 33%). The genetic change pattern with the locus of colorectal carcinoma was shown mean 3.1 (amplification 1.7, deletion 1.4) on the right colorectal carcinoma, while rectal carcinoma appeared high mean 6.3 (amplification 3.7, deletion 2.6) (p<0.001). The genetic change pattern with lymphatic gland metastasis, mean 3.5 (amplification 2.2, deletion 1.3) from "no metastasis" group, while high mean 6.3 (amplification 3.5, deletion 2.8) from metastasis group (p<0.003). The genetic change pattern with disease stages appeared mean 3.5 (amplification 2.1, deletion 1.4) from I-II stages, while high mean 6.0 (amplification 3.4, deletion 2.6) from III-IV stages (p<0.006). No significance was observed in comparing histological classification and serum CEA increased groups.