• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.04a
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• pp.115.2-115
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• 1979

By employing a two-stage continuous culture system, some of important physiological parameters involved in cellulase bicsynthesis have been evalua-ted with an ultimate objective of detigning an op-timally controlled tellulase process. Volumetric and specific cellulase productivities obtained were 90 IU/liter/hr and 8IU/g biomass/hr respectively. The maximum specific enzyme productivity observed was 14.8 IU/g hiomass/hr. The optimal dilution rate in the second stage which corresponded to the maximum enzyme productivity was 0.026-0.028 hr$^{-1}$ , and the specific growth rate in the second stage ihat suported maximum specific enzyme productivity was equal to orslightly less than zero. The maintenance coefficients deter-mined for oxygen and for carbon source are M$_{o}$=0.85mmmole/g biomass/hr and M$_{c}$=0.14 mmole hexose/g bio mass/hr respectively. The yield constants determined are; Y(x/o) =32.3g biomass/mole oxygen, Y (x/c) =1.1g bio-mass/g carbon or 0.44g biomass/g hexose, Y(x/n) = 19.6g biomass/g nitrogen for the enzyme produc-tion stage and 12.5g biomass/g nitrogen for the cell growth stage.e.e.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.249-253
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• 2000

Oral and Maxillofacial defects is produced by trauma or cancer surgery. This defects have been shown functional loss such as mastication, swallowing, speech and psychosocial esthetic problem. Oral and Maxillofacial defects is reconstructed by the use of many flaps. However although previous flap surgery was done, additional soft tissue defects can be still remained. In this case, Walk-Up flap that is introduced by Marx RE in 1990 is recommended for successful reconstruction. We report Walk-Up flap for reconstruction of remained soft tissue defects of tongue S.C.C. After induction chemotherapy, tongue S.C.C. is excised surgically and reconstructed by use of PMMC flap. Post-op infection results in surrounding soft tissue defect with oro-facial fistula. We have experienced a case of Walk-up flap by use of PMMC flap for reconstruction with satisfactory result, so we report it with literature reviews.

• The Journal of Korea Robotics Society
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• v.8 no.2
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• pp.92-103
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• 2013

Humanoid robot is the most intimate robot platform suitable for human interaction and services. Biped walking is its basic locomotion method, which is performed with combination of joint actuator's rotations in the lower extremity. The present work employs humanoid robot simulator and numerical optimization method to generate optimal joint trajectories for biped walking. The simulator is developed with Matlab based on the robot structure constructed with the Denavit-Hartenberg (DH) convention. Particle swarm optimization method minimizes the cost function for biped walking associated with performance index such as altitude trajectory of clearance foot and stability index concerning zero moment point (ZMP) trajectory. In this paper, instead of checking whether ZMP's position is inside the stable region or not, reference ZMP trajectory is approximately configured with feature points by which piece-wise linear trajectory can be drawn, and difference of reference ZMP and actual one at each sampling time is added to the cost function. The optimized joint trajectories realize three phases of stable gait including initial, periodic, and final steps. For validation of the proposed approach, a small-sized humanoid robot named DARwIn-OP is commanded to walk with the optimized joint trajectories, and the walking result is successful.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.4
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• pp.317-323
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• 2004

We fabricated a MISFET using Pd/NiCr gate for the detecting of hydrogen gas in the air and investigated its electrical characteristics. To improve stability and high concenntration sensitivity and remove the blister generated by the penetration of hydrogen atoms Pd/NiCr catalyst gate metal are used as dual gate. To reduce the gate drift voltage caused by the inflow of hydrogen, the gate insulators of sensing and reference FFET were constructed with double insulation layers of silicon dioxide and silicon nitride. The hydrogen response of MISFET were amplified with the difference of gate voltages of both MISFET. To minimize the drift and the noise, we used a OP177 operational amplifier. The sensitivity of the Pd/NiCr gate MISFET was lower than that of Pd/Pt gate MISFET, but it showed good stability and ability to detect high concentration hydrogen up to 1000ppm.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1705-1707
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• 1997

In this work, a possible new PD de technique, based on the electro-optic effect(P effect), has been proposed. The refractive index ellipsoid of EO crystal, as $LiNbO_3$, is changed by both the externally a electric field and its hysteresis loop of which effect on this hysteresis loop gives rise t discrepancy of index variation. Therefore, an eq regarding the phase variation of modulated beam through $LiNbO_3$ crystal under applied e field, is newly proposed considering the influen hysteresis characteristics. For this purpose generated from needle-plane electrode in oil has detected by use of $LiNbO_3$ cell and analyzed b equation. As a result, it is observed that PD measu phase intervals are limited by the cr characteristics such as asymmertrical P-E hyst and half-wave voltage.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.379-386
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• 2016

In this paper, phase noise analysis result for 2.4 GHz PLL(phase locked loop) using SPD(sample phase detector) is proposed. It can be used for high performance frequency synthesizer's LO(local oscillator) to extend output frequency range or for LO of offset PLL to reduce a division rate or for clock signal of DDS(direct digital synthesizer). Before manufacturing, theoretical estimation of PLL's phase noise performance should be performed. In order to calculate phase noise of PLL using SPD, Leeson model is used for modeling phase noise of VCO(voltage controlled oscillator) and OCXO(ovened crystal oscillator). After theoretically analyzing phase noise of PLL, optimized loop filter bandwidth was determined. And then, phase noise of designed loop filter was calculated to find suitable OP-Amp. Also, the calculated result of phase noise was compared with the measured one. The measured phase noise of PLL was -130 dBc/Hz @ 10 kHz.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.2
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• pp.150-157
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• 2021

Nowadays, a DC microgrid that can link various distributed power sources is gaining much attention. Accordingly, research on fault situations, such as line-to-line and line-to-ground faults of the DC microgrid, has been conducted to improve grid reliability. However, the blackout of an AC system and the oscillation of a DC bus voltage have not been reported or have not been sufficiently verified by previous research. In this study, a 20 kW DC microgrid testbed using a power HIL simulation technique is proposed. This testbed can simulate various fault conditions without any additional grid facilities and dangerous experiments. It includes the blackout of the DC microgrid caused by the AC utility grid's blackout, a drastic load increment, and the DC bus voltage oscillation caused by the LCL filter of the voltage source converter. The effectiveness of the proposed testbed is verified by using Opal-RT's OP5707 real-time simulator with a 3 kW prototype three-port dual-active-bridge converter.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.121-126
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• 2002

The railroad cars or the commercial vehicles are generally manufactured by the spot welding. Among various kinds of spot welded lap joints, multi-lap joints are one of popular joints in manufacturing their body structures. But, fatigue strength of these joints are lower than that of base metal due to high stress concentration at the nugget edge of the spot weld and are known to considerably be influenced by welding conditions as well as the mechanical and geometrical factors. Thus, it is necessary to establish a reasonable and systematic fatigue design criterion for spot welded multi-lap joints. In this paper, the $\Delta$P-N$_{f}$ curves has been rearranged in the $\Delta$$\sigma$-N$_{f}$ relation with the maximum stress at the nugget edge of spot welded multi-lap joints subjected to tensile shear load. Consequently, the fatigue data were evaluated in terms of fracture mechanics by plotting on the $\Delta$OP-N$_{f}$ curves. From the results obtained, both of them have been revealed to be applicable to fatigue design of spot welded multi-lap joints. However, the fracture mechanical approach is found to be more effective than the maximum stress approach in the range on N$_{f}$$\geq$2x10$^{5}$ . .

• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.247-255
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• 2016

This study was performed to investigate the effect of packaging materials on quality characteristics of washed potatoes such as Hunter's a value, chlorophyll and potato glycoalkaloids (PGA) content during their storage for 15 days. Packaging methods were evaluated into five ways: no packaging (NP, positive control), paper bag (PB, negative control), onion net (ON), transparent oriented to polypropylene without hole (TP), opaque oriented polypropylene with 4 holes (OP). Hunter's a values of washed potatoes showed minus in NP and TP after 12 days storage, whereas all plus values were observed in those of PB, ON, and OP. Total chlorophyll content of washed potatoes was the highest in no packaging at 15 days after storage. The PGA content of washed potatoes showed low levels in flesh part (below $5mg/100g{\cdot}FW$) as well as in peel part ($4.5-9.3mg/100mg{\cdot}FW$) in all packagings up to 15 days after storage.

• The Research Journal of the Costume Culture
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• v.17 no.3
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• pp.407-423
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• 2009

The purpose of this study is to analyze Bakst's stage costume illustrations for Ballets Russes. The Russian Ballets has renown in the West since the early 20th century. Diaghilev first made his name as the organizer of art exhibitions in Russia and Western Europe. Diaghilev risked presenting only ballets in 1909, that time Bakst designed $Sch{\acute{e}}h{\acute{e}}razade$, L'Oiseau de Feu and Le Carnival. $Sch{\acute{e}}h{\acute{e}}razade$ was something new which overwhelmed the French people by then. It was seen to be the achievement of Wagner's idea where all the elements; the music, the design, the choreography, and the dancing fused into a perfect whole. The entire production was a hitherto unseen harmony of colors, sounds and movements. For the 1911 season in Paris, Diaghilev planned to present six new ballets and Bakst designed four ballets. Bakst's design of the set and the costume greatly shocked the audience. His "Originality" shines on the fact that he introduced a palette of colors in theater for the first time in history. He used a magic of colors to suggest the secret meaning of what was happening on the stage. The results can be divided into three distinct characteristics. First, oriental designs such as $Cl{\acute{e}}op{\hat{a}}tre$, $Sch{\acute{e}}h{\acute{e}}razade$, L'Oiseau de Feu, La $P{\acute{e}}ri$ and Le Dieu Blue with Russian, Indian and Persian traditional design in headdress and accessories ars found. Second, Le Carnival and La Spectre de la Rose used romantic styles with oriental details. Third, Greek chiton and Himation are used in Narcisse, $H{\acute{e}}l{\grave{e}}ne$ de Sparte, $L'Apr{\grave{e}}s-Midi\;d^{\grave{\;}}un$ Faune and Daphnis et $Chlo{\acute{e}}$ inspirde with various colors and geometic patterns. Bakst's orient of lush colored costumes, head dress, cushions, rugs and hangings became the immediate fashion imitated by Parisian couture houses and interior decorators.