• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.28-31
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• 2016

In this study, it was investigated about optical simulation in highg brightness and high uniformity direct-type backlight design for medical application. Direct-type backlight has been used high-brightness backlight such as Medical LCD application. The key parameter in designing direct-type backlight was consists of three geometrical dimension such as the distance of two lamps, the gap of lamp and reflection plate and the number of lamps. It has many of variations in optical design and it causes the different properties in backlight system. It shows the best values of above parameters; 26mm of the distance of two lamps, 4.5mm of the gap of lamp and reflection plate and 16 lamps. And we produced the specimen as above condition, and acquired good result in backlight such as the value of the brightness is 6423 nit in center of emission area and less than 5% in brightness uniformity. It shows the effective ways of designing backlight system using optical simulation method for medical LCD application.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.221-224
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• 2003

Recently, TFT-LCD is widely used of medicine machine on the display devices. However, the display precision of TFT-LCD is 8 bits instead of 10 bits of CRT display. If the medical image have more than 8 bits, we must requantize the medical image. We propose an efficient method to reduce medical image from 10 bits into 8 bits by employing human visual perception. The proposed method shows good performance for the medical image display.

• Transactions on Electrical and Electronic Materials
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• v.9 no.1
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• pp.16-19
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• 2008

In this study, it was investigated about optical simulation in direct-type backlight design. Direct-type backlight has been used high-brightness backlight such as medical LCD application. The key parameter in designing direct-type backlight was consists of three geometrical dimension such as the distance of two lamps, the gap of lamp and reflection plate and the number of lamps. It has many of variations in optical design and it causes the different properties in backlight system. It shows the best values of above parameters; 26 mm of the distance of two lamps, 4.5 mm of the gap of lamp and reflection plate and 16 lamps. And we produced the specimen as above condition, and acquired good result in backlight such as the value of the brightness is 6423 nit in center of emission area and less than 5 % in brightness uniformity. It shows the effective ways of designing backlight system using optical simulation method for medical LCD application.

• Korean Journal of Ophthalmology
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• v.32 no.6
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• pp.470-477
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• 2018

Purpose: To investigate the relationship between the progression of visual field (VF) loss and changes in lamina cribrosa depth (LCD) as determined by spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging in patients with primary open angle glaucoma (POAG). Methods: Data from 60 POAG patients (mean follow-up, $3.5{\pm}0.7$ years) were included in this retrospective study. The LCD was measured in the optic disc image using SD-OCT enhanced depth imaging scanning at each visit. Change in the LCD was considered to either 'increase' or 'decrease' when the differences between baseline and the latest two consecutive follow-up visits were greater than the corresponding reproducibility coefficient value ($23.08{\mu}m$, as determined in a preliminary reproducibility study). All participants were divided into three groups: increased LCD (ILCD), decreased LCD (DLCD), and no LCD change (NLCD). The Early Manifest Glaucoma Trial criteria were used to define VF deterioration. Kaplan-Meier survival analysis and Cox's proportional hazard models were performed to explore the relationship between VF progression and LCD change. Results: Of the 60 eyes examined, 35.0% (21 eyes), 28.3% (17 eyes), and 36.7% (22 eyes) were classified as the ILCD, DLCD, and NLCD groups, respectively. Kaplan-Meier survival analysis showed a greater cumulative probability of VF progression in the ILCD group than in the NLCD (p < 0.001) or DLCD groups (p = 0.018). Increased LCD was identified as the only risk factor for VF progression in the Cox proportional hazard models (hazard ratio, 1.008; 95% confidence interval, 1.000 to 1.015; p = 0.047). Conclusions: Increased LCD was associated with a greater possibility of VF progression. The quantitative measurement of LCD changes, determined by SD-OCT, is a potential biomarker for the prediction of VF deterioration in patients with POAG.

• Progress in Medical Physics
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• v.17 no.2
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• pp.77-82
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• 2006

The image display is an Important component of PACS and of medical digital imaging chain. Displayed image qualify is affected by the physical characteristics of display device, appropriate clinical settings and calibrations, and ambient lighting conditions. The performance of display systems is continuously degraded over time due to luminance deterioration and changes of clinical setting parameters. A routine QC is recommended because the performance of display systems is continuously degraded over time. Ten flat panel monochrome LCD display devices were included in the evaluation of the QC effect. The effect of QC on primary class LCD medical display devices for selected QC tests was evaluated by comparing the performances, luminance response, luminance dependencies, display resolution and display chromaticity in this study, of before and after the calibration procedures. The effects of the QC are significant to luminance response and luminance spatial dependencies test and the other side, are slight to the display resolution and display chromaticity test. A routine QC of display device is essential for the consistency of medical image display and presentation. The study of the QC effects of display devices will play an important role in practical QC procedures of display devices.

• Journal of Digital Contents Society
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• v.5 no.1
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• pp.73-78
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• 2004

In this paper we implemented a field-sequential stereoscopic endoscope system that can generate stereoscopic images with different perspective depth using LCD shutter. The stereoscopic image is generated form stereoscopic adapter that has LCD shutter. We have compared the stereoscopic depth of a field-sequential stereoscopic endoscope system with that of the conventional endoscope system. And the implemented system is verified by evaluation the field-sequential stereoscopic image on a Monitor. This system will be use to medical instruments in time.

• Korean Journal of Oriental Medicine
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• v.17 no.2
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• pp.115-120
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• 2011

Objectives : The purpose of this study is to develop an apparatus which can take a facial image by self-operated capturing technique. The user can obtain one's facial image immediately after adjusting facial tilt and focusing distance. The system has been designed for classifying Sasang typology based on facial image. Methods : The system is composed of a Webcam, one-way glass mirror and mini LCD. The Webcam takes a facial image which is displayed on the mini LCD. Then the user can see and adjust to the right position in the real time through the image mirror-reflected from the mini LCD. The optical sensor is used to estimate the proper focusing distance. To verify the performance of the system, 11 characteristic points on the facial image are used and compared with high performance DSLR camera(D700) by applying the coefficient of variance and Bland-Altman Plot. Results : The developed system and D700 show enough agreement with the small coefficient of variance to analyse constitutional types with a facial im mage. However, the result of Bland-Altman plot shows that the width parameters have distortions owing to short focusing distance. Conclusions : The system is expected to be utilized on u-healthcare services for home environment after improving the distortion in the width parameters.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1245-1252
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• 2022

Induced pluripotent stem cells (iPSCs) can be generated from somatic cells using Oct4, Sox2, Klf4, and c-Myc (OSKM). Small molecules can enhance reprogramming. Licochalcone D (LCD), a flavonoid compound present mainly in the roots of Glycyrrhiza inflata, acts on known signaling pathways involved in transcriptional activity and signal transduction, including the PGC1-α and MAPK families. In this study, we demonstrated that LCD improved reprogramming efficiency. LCD-treated iPSCs (LCD-iPSCs) expressed pluripotency-related genes Oct4, Sox2, Nanog, and Prdm14. Moreover, LCD-iPSCs differentiated into all three germ layers in vitro and formed chimeras. The mesenchymal-to-epithelial transition (MET) is critical for somatic cell reprogramming. We found that the expression levels of mesenchymal genes (Snail2 and Twist) decreased and those of epithelial genes (DSP, Cldn3, Crb3, and Ocln) dramatically increased in OR-MEF (OG2^+/+/ROSA26^+/+) cells treated with LCD for 3 days, indicating that MET effectively occurred in LCD-treated OR-MEF cells. Thus, LCD enhanced the generation of iPSCs from somatic cells by promoting MET at the early stages of reprogramming.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.121-123
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• 2002

Fast response characteristics of twisted nematic liquid crystal display (TN-LCD) cell with different nematic liquid crystals (NLCs) and cell gap on a rubbed polyimide (PI) surface were studied. High transmittance and fast response time of the TN-LCD on the rubbed PI surface were achieved by using high birefringence ($\Delta$ n) and low cell gap. It is considered that the transmittance and response time of the TN-LCD on the rubbed PI surface decreased as $\Delta$ nd decrease.

• Analytical Science and Technology
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• v.25 no.2
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• pp.127-132
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• 2012

A test tool for self-leveling and flowing characters of coating materials used to semiconductors and electronic parts, especially for protection of LCD and PDP connectors, was designed, and the test tool was evaluated using polymeric siloxane coating materials which have various viscosities. The test results showed that the designed test tool was effective to measure self-leveling and flowing properties of coating materials. Therefore, considering that the viscosity is not directly correlated with self-leveling and flowing properties, we believe that this test tool will be a very useful tool for measurement instead of classical method using viscosities of coating materials. Particularly, the measurement of self-leveling and flowing properties using the test tool would be expected to be used in the area of selecting suitable protective coating materials for LCD (Liquid Crystal Display), PDP (Plasma Display Panel) and semiconductor connection parts.