• Journal of the Korean Society of Systems Engineering
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• v.13 no.2
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• pp.1-8
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• 2017

The Core in Weapon system R&D is to realize the user required capabilities in limited schedule and cost. Therefore, the design of weapon system focuses to functional design for realization of requirement capabilities. However, the weapon system should not only basically bring the confidence to friendly forces bring fear to enemy forces to maximize the operational effectiveness of weapon systems and we consider the exterior design as the important factor to compete with foreign systems in international defense market besides capabilities and cost. For that reason, we made study case about the visual design decision process applied to the LVT(light tactical vehicle) project which was recent successful deployment among the many R&D projects of auto industry. Based on this case, this study suggests the necessity of the exterior design decision process the maneuver weapon system is developed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.9
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• pp.850-857
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• 2011

Generally, sound-absorbing materials in vehicles are used for giving the comfort to passengers by reducing noise while driving. Materials of which targets are light weight, high performance, eco friendliness and recycling have been developed recently. In this study, sound-absorbing materials using PET(polyethylene terephthalate) hollow fibers to achieve the light weight and the high sound absorption performance are developed, and then evaluated to meet a requirement for the automotive components. The test results show that the acoustic performances of developed products having new fiber structure are better than those of the conventional product.

• Journal of the Korean Graphic Arts Communication Society
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• v.14 no.1
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• pp.89-114
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• 1996

Liquid crystal-polymer composite(LCPC) films consisting of a continuous LC phase embedded in a three-dimensional network of polymer matrix are formed by photopolymerization-induced phase separ on. The LCPC films are switched from a light-scattering stats to a highly transparent stats on the application of electric fields. Since the alignment of LC molecular determines the electro-optical properties of films, the requirement for good contrast is to generate the nematic phase at high concentration. On the other hand, the concentration of UV-curable monomer must be increased above some critical value to from the flexible matrix of unbounded polymer. The mixing ratio of LC and UV-curable monomer affects the electro-optical and viscoelastic properties of LCPD films in two opposing ways. By controlling the phase separation process, at an LC fraction of 0.7, the maximum performance of LCPC films has been achieved, the response time of which is 2ms on the application of electric fields.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.178-181
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• 2001

The organic light-emitting devices (OLEDs) based on fluorescence have low efficiencies due to the requirement of spin-symmetry conservation. By using the phosphorescent material, the internal quantum efficiency can reach 100 %, compared to 25 % in the case of the fluorescent material. Thus, the phosphorescent OLEDs have recently been extensively studied and showed higher internal quantum efficiencies then the conventional OLEDs. In this study, we investigated the characteristics of the phosphorescent OLEDs, with the green emitting phosphor, Ir(ppy)$_3$ (tris(2-phenylpyridine)iridium). The devices with a structure of ITO/TPD/Ir(PPy)$_3$ doped in the host material/BCP/Alq$_3$/Li:Al/Al were fabricated, and its electrical and optical characteristics were studied. By changing the doping concentration of Ir(PPy)$_3$ and the host materials, we fabricated several devices and investigated the device characteristics.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.8
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• pp.1000-1003
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• 2014

There are 70 vertical and 70 horizontal correctors for Pohang Light Source. Until mid of 2000, power supplies for these correctors were based on 1990's technology, so the global orbit feedback system was not possible with poor 12 bit resolution. A new task force team was assembled to develop new power supplies with BESSY type DAC cards. After the project, two vertical correctors in each lattice were connected with new power supplies, and the global orbit feedback was available within the accuracy of 5 microns. However, this replacement was not enough to satisfy the beam stability requirement of 2 microns for PLS. We have launched another power supply design based on all digital technology. This attempt was completed within a year, and 80 units were assembled in house. Currently, the global orbit feedback system is running successfully with new digital power supplies and the compensation of chamber motion due to the thermal load by using digital displacement transducers attached on each BPMs.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.2050-2055
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• 2009

This paper describes the proceeding experimental results to replace the 32 [W] fluorescent lamp installed in subway train to a LED module. We fabricated 25 [W] LED modules to meet the illuminance 300 [lx] specified in the standard for subway train. After the installation of LED modules, comparative analysis with conventional fluorescent lamps was carried out. From the experimental results, illuminances on the height of 0.85 [m] and 1 [m] above floor were 323 [lx] and 360 [lx], respectively. These illuminances satisfied the requirement 300 [lx]. By the application of 25 [W] LED module as a light source in subway train, energy saving about 22 [%] compared with 32 [W] fluorescent is acquired. Also, low cost of maintenance is expected due to 8 times longer lifetime 50,000 hours of LED than that 6,000 hours of fluorescent lamp.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.409-414
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• 2003

In this study we examined the method to select the size of the conductor rail for light rail system. Study results shows that using the conductor rail with lower resistivity requires fewer power substation, which results in lower construction cost. It also produces less copper loss. Therefore first choose the conductor rail with lowest resistivity and select the substation location, Next conduct computer simulation study to confirm it meets voltage requirement. if the minimum voltage is well above the required minimum voltage, substation number can probably be further reduced.

• Journal of Mushroom
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• v.8 no.4
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• pp.137-141
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• 2010

This experiment was carried out to clarify the effect of light qualities on the growth characteristics and yield of fruiting body in the cultivation of Lyophyllum ulmarium. The intensity of illumination by light qualities was in the order of white light(2,270Lux), yellow light(1,750Lux), blue light(460Lux) and red light(400Lux). An investigation of fruiting body showed these results that the pileus size and stipe diameter of fruiting body on CBM(Chungbuk mushroom)-1757 were much larger than Hypsizigus marmoreus, and an effect of yellow light seemed to be better than those of another light. In comparison with Hypsizigus marmoreus, the growth duration of CBM-1757 was shortened by 8 days which included 2 days for mycelial culture, 1 day for first pinning requirement and 1 day for growth. The growth duration in yellow light illumination was about 70 days showing the tendency of 2~4 days reduction. There were no differences in results such as number of effective stem and fresh weight. The yield of fruiting body per bottle in CBM-1757(95.6g) was little higher than Hypsizigus marmoreus(94.8g). By a white light's standard, the yields of blue and red light illumination were decreased by 2~9%, but that of yellow light illumination was increased by 8%. The chromaticity results showed that brightness, red and yellow coloration of CBM-1757 were higher than those of Hypsizigus marmoreus, and yellow light treatment was more effective than another light.

• Korean Journal of Plant Resources
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• v.8 no.1
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• pp.41-46
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• 1995

This experiment was carried out to investigate the effects of temperature, light quality and gibberellic acid on the seed germination of Rhododendron weyrichii Max. Optimum temperature for germination was $20^{\circ}C$ at constant temperature, but the final germination rate at $15^{\circ}C$ was about the same with the rates were attained by alternating temperature under higher temperature such as $25^{\circ}C$ or $30^{\circ}C$. The germination rate was increased by yellow and red light treatments at $20^{\circ}C$, but green light treatment strongly inhibited seed germination at $25^{\circ}C$. Gibberellic acid substitutes light requirement for germination of R. weyrichii seeds.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.374-374
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• 2012

Nowadays, Active Matrix Organic Light-Emitting Diodes (AM-OLEDs) are the superior display device due to their vivid full color, perfect video capability, light weight, low driving power, and potential flexibility. One of the advantages of AM-OLED over Liquid Crystal Display (LCD) lies in its flexibility. The potential flexibility of AM-OLED is not fully explored due to its sensitivity to moisture and oxygen which are readily present in atmosphere, and there are no flexible encapsulation layers available to protect these. Therefore, we come up with a new concept of Inorganic-Organic hybrid thin film as the encapsulation layer. Our Inorganic layer is Al2O3 and Organic layer is F-Alucone. We deposited these layers in vacuum state using Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) techniques. We found the results are comparable to commercial requirement of 10-6 g/m2 day for Water Vapor Transmission Rate (WVTR). Using ALD and MLD, we can control the exact thin film thickness and fabricate more dense films than chemical or physical vapor deposition methods. Moreover, this hybrid encapsulation layer potentially has both the flexibility of organic layers and superior protection properties of inorganic layer.