• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.221-224
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• 2001

The dynamic characteristics of a hydraulic press for micro-stamping are investigated by Finite Element Analysis. This machine requires high precision in producing milli-structure of electric products such as TFT-LCD back-up light reflector. First, the modal analysis of the parts and the assembly of the hydraulic press is performed. Then, the sensitivity analysis is carried out. The results show that the bearing stiffness and the base mounting stiffness affect the specific mode shapes.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.421-428
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• 1998

Sensitivity analysis of suspension elements of an articulated bogie for light railway vehicles is presented. The ride, stability and safety are used as dynamic performance index. Suspension elements of 10 and a conicity of wheel are used as design variables, To analyze sensitivity of design variables, the railway vehicle dynamics analysis program AGEM is used. The results shows that the secondary suspension elements have a strong effect on ride and the primary suspension elements have a moderate effect on ride. Conicity of wheel has a strong effect on the stability, The safety is not effected by all the design variables.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.247-252
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• 2014

Purpose: This study was to investigate the properties and the location of neural reorganization following eccentric viewing training. Methods: 14 subjects with normal vision took part in eccentric viewing training. The measurements of the light sensitivity and multifocal electroretinogram were performed before and after the training. Results: The measurements of the light sensitivity and multifocal electroretinogram for pre-eccentric viewing training and post-eccentric viewing training showed the significant difference (p<0.047 and p<0.028, respectively). Conclusions: The retinal outer plexiform layer is unable to regenerate. However, the neural reorganization in the retinal outer plexiform layer is able to take place following eccentric viewing training.

• Journal of Sensor Science and Technology
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• v.27 no.3
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• pp.160-164
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• 2018

In this paper, a wide dynamic range complementary metal-oxide-semiconductor (CMOS) image sensor with the adjustable sensitivity by using cascode metal-oxide-semiconductor field-effect transistor (MOSFET) and inverter is proposed. The characteristics of the CMOS image sensor were analyzed through experimental results. The proposed active pixel sensor consists of eight transistors operated under various light intensity conditions. The cascode MOSFET is operated as the constant current source. The current generated from the cascode MOSFET varies with the light intensity. The proposed CMOS image sensor has wide dynamic range under the high illumination owing to logarithmic response to the light intensity. In the proposed active pixel sensor, a CMOS inverter is added. The role of the CMOS inverter is to determine either the conventional mode or the wide dynamic range mode. The cascode MOSFET let the current flow the current if the CMOS inverter is turned on. The number of pixels is $140(H){\times}180(V)$ and the CMOS image sensor architecture is composed of a pixel array, multiplexer (MUX), shift registers, and biasing circuits. The sensor was fabricated using $0.35{\mu}m$ 2-poly 4-metal CMOS standard process.

• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.79-82
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• 2015

This paper proposes a novel complementary metal oxide semiconductor (CMOS) active pixel sensor (APS) and presents its performance characteristics. The proposed APS exhibits a linear-logarithmic response, which is simulated using a standard $0.35-{\mu}m$ CMOS process. To maintain high sensitivity and improve the dynamic range (DR) of the proposed APS at low and high-intensity light, respectively, two additional nMOSFETs are integrated into the structure of the proposed APS, along with a photogate. The applied photogate voltage reduces the sensitivity of the proposed APS in the linear response regime. Thus, the conversion gain of the proposed APS changes from high to low owing to the addition of the capacitance of the photogate to that of the sensing node. Under high-intensity light, the integrated MOSFETs serve as voltage-light dependent active loads and are responsible for logarithmic compression. The DR of the proposed APS can be improved on the basis of the logarithmic response. Furthermore, the reference voltages enable the tuning of the sensitivity of the photodetector, as well as the DR of the APS.

• The Korean Journal of Ecology
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• v.8 no.2
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• pp.69-73
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• 1985

Germination respone to sulfuric acid treatment, temperature, light and underwater condition were experimented for Albizzia julibrissin Durazz. seed. It took 60 minutes to break the dormancy of impermeable seed for the effective sulfuric acid treatment, and temperature sensitivity was decreased by 90 minutes' treatment. The germination rate of the seed was highest, i.e. 96% at 60 minutes acid treatment in a 21。C growth chamber. On the occasion of light sensitivity, the seed was light indifferent. The imbibition rate of seed was higher at 27。C than 21。C and in proportion to the period of acid treatment time. A. julibrissin Durazz. seed were well germinated at underwagter condition.

• Journal of the Korean Magnetics Society
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• v.10 no.2
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• pp.93-98
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• 2000

Drive line shape for reflective magneto-optic spatial light modulator has been designed by computer simulation. A factor of 3 improvement in pixel switching sensitivity and power consumption, compared to the conventional reflective magneto-optic spatial light modulator, has been achieved by the use of wedge-shape drive line and a soft magnetic layer. A factor of 2 higher optical efficiency and a factor of 2 simpler fabrication process have been achieved by the use of drive lines that covers most of the surface of pixel and unpatterned insulator.

• Journal of Information Display
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• v.13 no.1
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• pp.43-49
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• 2012

Depth sensitivity is considered one of the factors influencing 3D displays the most. In this paper, the perceptual 3D depth was quantitatively measured to compare the depth difference among the display devices. No difference was found in the typical display performance among the devices, but the subjective evaluation of the depth sensitivity where the disparity was varied showed that the organic light emitting diode (OLED) had the highest performance, mainly due to its almost 0% crosstalk, one of the features of OLED. Crosstalk is a form of image superposition that greatly affects the depth sensitivity. The experiment results showed that the quantitative depth sensitivity varies due to geometric factors such as disparity, viewing distance, and subjective sensitivity, depending on the display image characteristics, such as crosstalk and contrast.

• Current Optics and Photonics
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• v.7 no.2
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• pp.200-206
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• 2023

Near-infrared (NIR) sensing technology using CMOS image sensors is used in many applications, including automobiles, biological inspection, surveillance, and mobile devices. An intuitive way to improve NIR sensitivity is to thicken the light absorption layer (silicon). However, thickened silicon lacks NIR sensitivity and has other disadvantages, such as diminished optical performance (e.g. crosstalk) and difficulty in processing. In this paper, a pixel structure for NIR sensing using a stacked CMOS image sensor is introduced. There are two photodetection layers, a conventional layer and a bottom photodiode, in the stacked CMOS image sensor. The bottom photodiode is used as the NIR absorption layer. Therefore, the suggested pixel structure does not change the thickness of the conventional photodiode. To verify the suggested pixel structure, sensitivity was simulated using an optical simulator. As a result, the sensitivity was improved by a maximum of 130% and 160% at wavelengths of 850 nm and 940 nm, respectively, with a pixel size of 1.2 ㎛. Therefore, the proposed pixel structure is useful for NIR sensing without thickening the silicon.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.31-34
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• 2002

In this paper, the electric properties of amophous selenium multilayer samples has been investigated. In order to develop the hybrid flat-panel digital· X-ray image detector, we measured and analyzed their performance parameters such as the X -ray sensitivity and dark-current for a amophous selenium multilayers X-ray detector with a phosphor layer, The hybrid digital X-ray image detector can be constructed by integrating a phosphor layer (or a scintillative layer) that convert X-ray to a light on a-Se photoconduction mulilayers that convert a light to electrical signal. As results, the dielectric materials such as parylene between the phosphor layer and the top electrode may reduce the dark-current of the samples. Amorphous selenium multilayers having dielectric layer(parylene) has characteristics of low dark-current, high X-ray sensitivity. So we can acquired a enhanced signal to noise ratio. In this paper offer the method can reduce the dark-current in the hybrid X-ray detector.