• Journal of the Semiconductor & Display Technology
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• v.12 no.4
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• pp.45-48
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• 2013

The electronic device, such as flat panel display (FPD), is very important in our life as a means of communication between humans. Liquid crystal display (LCD), which is categorized as a flat panel display, has been used in many display products, especially in TV industry. An LED TV is composed of several electrical components, such as liquid critical module (LCM), analog to digital convertor (AD), power supplier, and inverter board. These modules are very vulnerable to particulate contamination, and causing malfunction or visibility degradation. In this study, we developed a test method for prediction of LCM's lifetime. The test system consists of carbon particle generation flame, dilution system, test chamber, and particle concentration monitoring instrument. Since the carbon particles are the most abundant in the atmosphere and easily absorb light, soot particles are used as a challenging material for this test. The concentration of generated soot particles is set around 4,000,000 #/cc, which is 400 times higher than that of usual atmospheric particles. Through this experiment, we deduced the relationship between the dust concentration and life time of the test specimen.

• International Journal of Automotive Technology
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• v.8 no.1
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• pp.67-73
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• 2007

This study analyzes the interior noise that is generated during acceleration of a passenger car in terms of car body structure and panel contribution. According to the transfer method, interior noise is classified into structure-borne noise and air-borne noise. Structure-borne noise is generated when the engine's vibration energy, an excitation source, is transferred to the car body through the engine mount and the driving system and the panel of the car body vibrates. When structure-borne noise resonates in the acoustic cavity of the car interior, acute booming noise is generated. This study describes plans for improving the car body structure and the panel form through a cause analysis of frequency ranges where the sound pressure level of the rear seat relative to the front seat is high. To this end, an analysis of the correlation between body attachment stiffness and acoustic sensitivity as well as a panel sensitive component analysis were conducted through a structural sound field coupled analysis. Through this study, via research on improving the car body structure in terms of reducing rear seat noise, stable performance improvement and light weight design before the proto-car stage can be realized. Reduction of the development period and test car stage is also anticipated.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.139.2-139.2
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• 2005

• Journal of Ginseng Research
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• v.7 no.2
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• pp.172-192
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• 1983

Light environment and growth of Panax ginseng In habitat and cultivation under natural shade were renewed. Grower's experiences on ginseng stand In relation to light environment were assessed. Change of shading method and grower's concepts on light requirement of ginseng plant in Korea, Manchuria and Japan was counted. Growth of wild ginseng was better under rich light. Optimum crown density index appeared to be 0.7 In natural habitat and 0.4 to 0.7 for the cultivation in forest. Change of light Intensity in forest was greatest in May and reached near to constant value (from 40% to 3% for broad leaf deciduous forest and loom 4% to 2% for pine forest). Insufficient light condition induced long and thin stem, poor flowering and seed bearing, and sequent dormancy. Relation between light and ginseng strand was not clear but light Interception with cool weather was effective. Topography and orientation of bed have been deeply considered for light environment. Panel or bark of won were used for shading in deep forest manly In Manchuria while reed blind and straw thatch were used in Korea. Kinds and number of shades material and seasonal or daily schedule have been simplified probably by labor pressure due to eulargement of plantation. Post height has been greater while width of roof, bed and ditch has changed lisle. Scientific survey in the past omitted important light control methods (complete light hardening etc) which has been practiced in specific areas. The concept and technique of light control in the past in Korea were delicate and intensive including the control of temperature and moisture. For the application of old concept in modem cultivation precise Investigation of the technique including the measurement of light, temperature and moisture is needed.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.255-258
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• 2004

We have developed the Scan-backlight Stereoscopic LCD that is a kind of field-sequential -Stereoscopic LCD combining the Dual-Directional-Backlight and the fast-response OCB panel. The Dual-Directional-Backlight using a double-sided prism sheet can change the direction of light by switching the LED light sources. The OCB panel using Feed-Forward Drive can realize frame rate of 120 Hz. As a result, the Scan-backlight Stereoscopic display works at its original resolving power, and produces flicker-free stereoscopic images. This auto stereoscopic display can resolved the problems of the double images and the pseudoscopic images in case of watching at oblique angles.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.8
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• pp.703-709
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• 2010

An analysis tool for predicting transmission loss in high speed trains based on combined use of the statistical energy analysis and the finite element methods has been proposed. The analysis utilizes a commercially available numerical solver VA ONE with imbedded NASTRAN module. The proposed analysis tool is first verified by comparing numerically predicted transmission loss of a light rail transport(LRT) structure with experimental results. The comparison shows that the numerically predicted transmission loss is similar to the experimental data. The analysis tool is then applied to the prediction of transmission loss in the high speed train(HST) currently under development. Various sub-structures such as the floor, side panel and ceiling have been numerically analyzed to predict their transmission losses. The results obtained here can be used as input data for predicting the interior noise level of the HST at design stage.

• Transactions on Electrical and Electronic Materials
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• v.8 no.5
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• pp.215-217
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• 2007

Recently, color reproduction properties have attracted lots of attention with mass production of LCD especially corresponding to TV application and achievement of color reproduction properties such as CRT have been considered one of technical goals for high quality display. However, revision of the color reproduction properties only with CF(color filter) have fundamental limitations and resultant decrease in the transmittance of panel causes demand on high brightness of BL(Back Light). In this paper, we present such a method in which by optimization of original light spectrum from the BL source will improves the color reproduction properties corresponding to them of the CRT. When the intensity of RED and Green-Blue from ramp is revised densely, the characteristics different from CCFL(Cold Cathode Fluorescent Lamp) used before become added so that about 11 % of the color reproduction properties is improved compare to the existing LCD panel.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2227-2229
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• 1999

As a direct-view flat panel displays, there are many devices, such as plasma display panels(PDPs), vacuum fluorescent displays (VFDs), and light emitting diode(LED). Among these, a PDP is the first type of panel display to be made commercially available. A 'Plasma display' is the general term for a flat display utilizing the light emission that is produced by gas discharge. However, the brightness and Luminous efficiency are still not adequate for consumer television. So, the new sustain electrode type of ac PDP was proposed. By arranging the transparent electrode of quadrangle by zigzag, the area of electrode are reduced, and the length of electrode gap is increased. It generates a high luminous efficiency(corresponding to a 40% improvement of standard type), the same discharge voltage characteristics, and the low power consumption at same luminance.

• Macromolecular Research
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• v.14 no.1
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• pp.1-33
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• 2006

Polyimides (PIs) exhibit excellent thermal stability, mechanical, dielectric, and chemical resistance properties due to their heterocyclic imide rings and aromatic rings on the backbone. Due to these advantageous properties, PIs have found diverse applications in industry. Most PIs are insoluble because of the nature of the high chemical resistance. Thus, they are generally used as a soluble precursor polymer, which forms complexes with solvent molecules, and then finally converts to the corresponding polyimides via imidization reaction. This complexation with solvent has caused severe difficulty in the characterization of the precursor polymers. However, significant progress has recently been made on the detailed characterization of PI precursors and their imidization reaction. On the other hand, much research effort has been exerted to reduce the dielectric constant of PIs, as demanded in the microelectronics industry, through chemical modifications, as well as to develop high performance, light-emitting PIs and liquid crystal (LC) alignment layer PIs with both rubbing and rubbing-free processibility, which are desired in the flat-panel display industry. This article reviews this recent research progresses in characterizing PIs and their precursors and in developing low dielectric constant, light-emitting, and LC alignment layer PIs.

• Korean Journal of Optics and Photonics
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• v.23 no.3
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• pp.119-123
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• 2012

The structure of an LCD backlight unit (BLU) was simplified by installing a micro reverse-pyramid array (MRPA) or a micro reverse-cone array (MRCA) on the top surface of the light guide panel (LGP) in order to eliminate the conventional diffuser sheet and the prism sheet. The optimum conditions of the MRPA and the MRCA in the new light guide panel were obtained through optical simulation. The change of the luminance and view angle that depend on the side angle, the height, and the length at the top of the MRPA and MRCA were studied. The optimized side angle and the view angle of the MRPA and MRCA were 59 and 57 degrees for the side angles and 68 and 64 degrees for the view angles, respectively.