• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.54-63
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• 2011

This paper proposes a new equation to calculate computer-generated hologram (CGH) in a high speed and its cell-based VLSI (veri large scale integrated circuit) architecture. After finding the calculational regularity in the horizontal or vertical direction from the basic CGH equation, we induce the new equation to calculate the horizontal or vertical hologram pixel values in parallel. We also propose the architecture of the CGH cell consisting of a initial parameter calculator and update-phase calculator(s) on the basis of the equation and implement them in hardware. Also we show a hardware architecture to parallelize the calculation in the horizontal direction by extending CGH. In the experiments we analyze the used hardware resources. These analyses makes it possible to select the amount of hardware to the precision of the results. Here, for the CGH kernel and the structure of the processor, we used the platform from our previous works.

• Molecules and Cells
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• v.38 no.12
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• pp.1044-1053
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• 2015

This study first investigated the effects of corn gluten hydrolysate (CGH) (1.5 g/day) administration for 7 days on appetite-responsive genes in lean Sprague-Dawley (SD) rats. In a second set of experiments, the metabolic changes occurring at multiple time points over 8 weeks in response to CGH (35.33% wt/wt) were observed in high-fat (HF, 60% of energy as fat) diet-fed SD rats. In lean rats, the hypothalamus neuropeptide-Y and proopiomelanocortin mRNA levels of the CGH group were significantly changed in response to CGH administration. In the second part of the study, CGH treatment was found to reduce body weight and perirenal and epididymal fat weight. CGH also prevented an increase in food intake at 2 weeks and lowered plasma leptin and insulin levels in comparison with the HF group. This reduction in the plasma and hepatic lipid levels was followed by improved insulin resistance, and the beneficial metabolic effects of CGH were also partly related to increases in plasma adiponectin levels. The Homeostasis Model of Assessment - Insulin Resistance (HOMA-IR), an index of insulin resistance, was markedly improved in the HF-CGH group compared with the HF group at 6 weeks. According to the microarray results, adipose tissue mRNA expression related to G-protein coupled receptor protein signaling pathway and sensory perception was significantly improved after 8 weeks of CGH administration. In conclusion, the present findings suggest that dietary CGH may be effective for improving hyperglycemia, dyslipidemia and insulin resistance in diet-induced obese rats as well as appetite control in lean rats.

• Journal of Genetic Medicine
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• v.10 no.1
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• pp.52-56
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• 2013

Mosaic trisomy 14 syndrome is a well-known but unusual chromosomal abnormality with a distinct and recognizable phenotype. Array comparative genomic hybridization (CGH) analysis has recently become a widely used method for detecting DNA copy number changes, in place of traditional karyotype analysis. However, the array CGH shows a limitation for detecting the low-level mosaicism. Here, we report the detailed clinical and cytogenetic findings of patient with low-frequency mosaic trisomy 14, initially considered normal based on usual cut-off levels of array CGH, but confirmed by G-banding karyotyping. Our patient had global developmental delay, short stature, congenital heart disease, craniofacial dysmorphic features, and dark skin patches over her whole body. Estimated mosaicism proportion was 23.3% by G-banding karyotyping and 18.0% by array CGH.

• Korean Journal of Optics and Photonics
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• v.8 no.3
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• pp.194-198
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• 1997

We realized CGH display of moving objects with an optical addressed spatial light modulator. CGH was calculated by the horizontal parallex method for saving a calculating time, and calculation speed was improved by making a lookup table of trigonometric function and root calculation. This lookup table was applied to a low resolution SLM, and succeeded in a simultaneous display of the three hologram images by the scanning method.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.9-11
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• 2002

We improve the free-space optical interconnection efficiency by using circular aperture computer-generated hologram (CGH). In free-space optical interconnection system using CGH, the single CGH is composed of sub-CGHs, which can change the direction of input beams to desired output positions, by Fourier transform. Each sub-CGH is rectangular shape, so the input beams through each sub-CGH are transformed to sinc functions in output plane. The side lobes of each sinc function are superimposed in output plane and they result in detection error in output plane, so the detection efficiency is low. We use the circular shaped sub-CGHs in order to reduce the side lobe value in output plane instead of rectangular shaped sub-CGHs. The each input beam is transformed to first-order Bessel functions through circular shaped sub-CGHs in output plane. The side lobes of first-order Bessel functions us low values compared with side lobes of sinc function, so we can improve the detection efficiency in output plane. We use binary phase modulated CGH, and confirm this improvement results by simulation.

• Korean Journal of Optics and Photonics
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• v.11 no.2
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• pp.80-84
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• 2000

Parabolic almninium mlITOr of m.5('||'&'||'cent; 50 nun) was fabncated by a diamond tummg machine. Computer generated hologram (CGH) for the test of parabolic mirror was encoded by binary phase hologram Approximation of curved fringe to line was made by staircase encoding. After fringe data 1ransformed mto a Post Scnpt file. magnified master CGH was printed by a laser printer, and then it reduced to the photographIc film. Parabolic mirror was tested by Twyman-Green interferometer with CGH at VIewing arm. Its experimental result was compared with those of surface profile and auto-collimatIon test, and then the errors were analyzed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.571-572
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• 2020

3D 디스플레이 산업에 있어서 홀로그램의 상용화는 여전히 많은 문제점을 가지고 있다. Computer Generated Hologram(CGH)은 홀로그램 분야 중에서도 3D 물체를 생성하는데 여러 가지 강점을 가지고 있지만 큰 해상도를 가진 CGH를 생성하는데 많은 연산시간이 걸려 상업화에 걸림돌이 되고 있다. 이 논문에서는 이를 해결하기 위하여 오목 렌즈 함수를 이용한 초 고해상도 CGH를 생성하는 알고리즘을 이용하여 초 고해상도 홀로그램을 생성하는 방법을 제안하였다. 초 고해상도 CGH를 생성하기 위하여 필요한 일반적인 방법으로 실제로 계산해야 될 CGH의 크기는 4 메가픽셀(2k X 2k) 수준의 저해상도로서, 저사양의 컴퓨터로서도 충분히 빠르고 부담 없이 계산해낼 수 있는 사이즈이다. 생성된 CGH로 Array를 형성한 후, 해당 위치에 알맞은 임의의 오목 렌즈 함수를 곱해줌으로서 임의의 크기 및 복원 거리를 가지는 초고해상도 CGH를 생성할 수 있음을 확인하였다.

• Journal of the Optical Society of Korea
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• v.6 no.2
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• pp.21-26
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• 2002

Interferometric metrology with a null CGH(computer-generated hologram) is presented for measuring highly aspheric surfaces used in a large screen projection television system with high accuracy. The cubic spline surface model which works in a single-pass configuration with a refractive index of object space 0 is used for designing a null CGH. A hybrid null corrector with plano-concave lens in front of a CGH is presented to make the CGH easier to fabricate. Experimental results are presented to demonstrate the validity of the proposed technique.

• Broadcasting and Media Magazine
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• v.24 no.2
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• pp.32-38
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• 2019

컴퓨터 생성 홀로그래피(CGH)는 광파의 진행을 수치적으로 시뮬레이션하여 홀로그램 영상을 합성하는 연구분야이다. 실물 기반 홀로그램으로는 제작하기 어려운 다양한 가상 장면을 다룰 수 있으며 복잡한 광학계 구축 문제로부터 자유로운 장점 등으로 인하여 많은 연구가 진행되고 있다. 특히 대규모 병렬 처리가 가능한 범용 GPU의 발전은 CGH 실용화의 견인차가 되고 있다. 본 고에서는 CGH의 원리 소개와 함께 GPU에 기반한 CGH 고속화의 이슈 및 향후 전망을 살펴보고자 한다.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.706-717
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• 2015

The computer generated hologram (CGH) method is the technology which can generate a hologram by using only a personal computer (PC) commonly used. However, the CGH method requires a huge amount of calculational time for the 3D object with a super multi-light source or a high-definition hologram. Hence, some solutions are obviously necessary for reducing the computational complexity of a CGH algorithm or increasing the computing performance of hardware. In this paper, we propose a method which can generate a digital hologram of the 3D object with a super multi-light source using parallel distributed computing. The traditional methods has the limitation of improving CGH performance by using a single PC. However, the proposed method where a server PC efficiently uses the computing power of client PCs can quickly calculate the CGH method for 3D object with super multi-light source. In the experimental result, we verified that the proposed method can generate the digital hologram with 1,5361,536 resolution size of 3D object with 157,771 light source in 121 ms. In addition, in the proposed method, we verify that the proposed method can reduce generation time of a digital hologram in proportion to the number of client PCs.