• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6C
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• pp.901-906
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• 2004

For a digital image watermarking some autostereograms are used such as random dot images. In there, the extraction efficiency is good and the distortion rate is low. In this paper, we shall select an optimized scaling parameter which derives low distortion rate and high extraction efficiency, when we use a random dot images as like as autostereograms into some images except for extremely biased gray level images.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.1-4
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• 2000

The test of stereoacuity provides relatively accurate assessment of binocular functior. in the clinical fields. The purpose of this study was to investigate performance on the Random-dot E(RDE) stereotest under the binocular conditions by the difference of the illumination and test distance. The more light illumination increase. The more pass of RDE stereotest increase. On the other hand. On the near distance of test target. All subjects have a pass toe RDE stereatest. But On the far distance of test target. Some subjects have a pass the RDE stereatest. According to the test distance. The more far distance of test target. the less subjects have a pass the RDE stereotest. As a results, The RDE stereotest have effected the test distance and illumination.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.267-274
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• 2022

In this paper, we report the design and fabrication of binary diffractive optical elements (DOEs) for random-dot-pattern projection for Schlieren imaging. We selected the binary phase level and a pitch of 10 ㎛ for the DOE, based on cost effectiveness and ease of manufacture. We designed the binary DOE using an iterative Fourier-transform algorithm with binary phase optimization. During initial optimization, we applied a computer-generated pseudorandom dot pattern of uniform intensity as a target pattern, and found significant intensity nonuniformity across the field. Based on the evaluation of the initial optimization, we weighted the target random dot pattern with Gaussian profiles to improve the intensity uniformity, resulting in the improvement of uniformity from 52.7% to 90.8%. We verified the design performance by fabricating the designed binary DOE and a beam projector, to which the same was applied. The verification confirmed that the projector produced over 10,000 random dot patterns over 430 mm × 430 mm at a distance of 5 meters, as designed, but had a slightly less uniformity of 84.5%. The fabrication errors of the DOE, mainly edge blurring and spacing errors, were strong possibilities for the difference.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.66-71
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• 2002

In Generally, a imbedding and extracting is good as watermark using a random dot image. In this paper, when the autostreogram which has some randomness is used watermark image, distortion rate is low and extraction rate is high. Using this quality, when any logo image is transformed to same image domain randomly, distortion rate is low and extraction rate is high, more over the robustness is good in spite of hard clipping.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.66-71
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• 2002

In Generally, a imbedding and extracting is good as watermark using a random dot image. In this paper, when the autostreogram which has some randomness is used watermark image, distortion rate is low and extraction rate is high. Using this quality, when any logo image is transformed to same image domain randomly, distortion rate is low and extraction rate is high, more over the robustness is good in spite of hard clipping.

• Carbon letters
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• v.21
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• pp.8-15
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• 2017

The thermoelectric Seebeck and Peltier effects of a single walled carbon nanotube (SWCNT) quantum dot nanodevice are investigated, taking into consideration a certain value of applied tensile strain and induced ac-field with frequency in the terahertz (THz) range. This device is modeled as a SWCNT quantum dot connected to metallic leads. These two metallic leads operate as a source and a drain. In this three-terminal device, the conducting substance is the gate electrode. Another metallic gate is used to govern the electrostatics and the switching of the carbon nanotube channel. The substances at the carbon nanotube quantum dot/metal contact are controlled by the back gate. Results show that both the Seebeck and Peltier coefficients have random oscillation as a function of gate voltage in the Coulomb blockade regime for all types of SWCNT quantum dots. Also, the values of both the Seebeck and Peltier coefficients are enhanced, mainly due to the induced tensile strain. Results show that the three types of SWCNT quantum dot are good thermoelectric nanodevices for energy harvesting (Seebeck effect) and good coolers for nanoelectronic devices (Peltier effect).

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.69-80
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• 2009

Purpose: We investigated validity of a monitor-based computer eye test program, Test Chart 2000 Pro (developed by Thomson Software Solutions, UK). Methods: We chose ten common eye tests of the Test Chart 2000 Pro and Korean Standard Eye Test, applying them to same subject groups each by each, followed by comparison and analyses of agreement degree of the results. Results: Among the ten eye tests, Snellen Chart, Cross-cyl target, Duochrome test, Fan and Block test, and Random dot stereograms showed statistically significant agreement between both the Korean standard eye test method and Test Chart 2000 Pro. On the other hand, some disagreements were found between the two eye test methods in LogMAR Chart, Single Letter Chart, Phoria Test, Fixation Disparity Test, and Worth 4 Dot Test. Conclusions: Comparing to the Korean Standard Eye Test that consists of Han eye chart and Phoroptor, validity of the Test Chart 2000 Pro is not so high. Further improvements of the Test Chart 2000 Pro in accuracy are required.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.11a
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• pp.729-732
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• 2003

In this paper, the transformed logo image is used as a watermark image, then the extraction rate is good when the logo image is transformed into randomly distribute Image domain. The robustness is good resist of clipping and noise.

• Korean Journal of Cognitive Science
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• v.10 no.3
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• pp.67-75
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• 1999

We investigated whether human could perceive the heading direction from the optic flow made from random dots and real images simulating the motion of the observer and objects. When an object moves across the focus of expansion(FOE) in random dot simulation. the observer perceived the focus of expansion biased toward the motion direction of the object. supporting the hypothesis that the direction repulsion is produced between the expansional and the horizontal planar motion components. With real image display observers tended to perceive one's heading direction biased toward the c center of the scene regardless of the direction and position of moving 0bcts. And it was observed that the deeper the depth of the background was the larger the judgment error was. These results suggest it is more likely that human depends on different cues than the optic flow when they perceive or judge one's heading direction in the real environment.

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.282-286
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• 2003

The purpose of this study was to isolate a specific DNA probe for the strain ATTC 25611 of the species Prevotella intermedia by using a new rapid screening mothod. The whole-genomic DNA of P. intermedia ATCC 25611 was isolated and purified. The HindIII-digested genomic DNAs from the strain were cloned by the random cloning method. To screen the strain-specific DNA probe, inverted dot blot hybridization tests were performed. In this assay, 20 ng of recombinant plasmids containing the HindIII-digested genomic DNA fragment were boiled and blotted onto a nylon membrane, and hybridized with digoxigenin-dUTP labeled genomic DNAs in a concentration of 100 ng/ml. Southern blot analysis was performed in order to confirm the results of the inverted dot blot hybridization tests. The data showed that a Pi34 probe (2.1 kbp; 1 out of 32 probes) was specific for P. intermedia strain ATCC 25611 and could be useful for the detection and identification of the strain, particularly in epidemiological studies of periodontal disease.