• 전기학회논문지
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• 제57권6호
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• pp.1032-1035
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• 2008

In this paper, a DC power management scheme is proposed for efficient battery operation of 60-GHz receivers. It consists of a rectenna and a zero-cross detector. The harmonic rejection capability of a circular sector antenna is used to simplify the rectenna. The zero-cross detector is introduced to increase sensitivity. When the received power density is larger than 0.013 $mW/cm^2$, it can generate enough DC power to activate an RF receiver. Experimental data is used to verify the proposed idea.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1635-1639
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• 2006

LTPS has potential capability to realize various kinds of circuit integrations on panel glass because of its relatively higher field effect mobility of around 100cm2/Vs. Recent progress of LTPS technologies and advanced technologies, which are generally called "System on Glass (SOG)," will be discussed. The technology includes circuit integration, photo-sensor integration for input functions, and display quality and performance improvement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1925-1927
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• 1999

At the study, it has fabricated Al/AlN/GaAs MIS capacitor using DC reactive sputtering method. To applicate GaAs semiconductor in a MIS devices, investigated capability of AIN thin film by the insulator layer. Also it has investigated inversion of C-V characteristics by addition of the hydrogen(hydrogen concentration: 5%) and it has investigated that leakage current has $10^{-8}A/cm^2$ for 1 MV/cm breakdown electric field of I-V characteristics.

• 한국양식학회지
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• 제9권4호
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• pp.453-459
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• 1996

Cellulase was purified from marine rotifer, Brachionus plicatilis, to homogeneity by using chromatographic methods. Purified enzyme is an endo-${\beta}$-1,4 glucanase and shows a strong hydrolytic activity against carboxymethyl (CM) -cellulose. The physicochemical parameters of enzyme activity were determined. The molecular weight of the purified protein was approximately 62 kDa as determined by SDS-polyacrylamide gel electrophoresis. The enzymatic capability to digest cellulose of Chlorella cell wall was compared with that of other well known cellulases from Thermomonospora fusca. Experiments involving Chlorella digestion indicated that CM-cellulase from marine rotifer, Brachionus plicatilis, could digest Chlorella very efficiently while cellulase purified from Thermomonospora fusca did not. From the result here, we propose that the cellulolytic system from marine rotifer is responsible for the hydrolysis of cellulosic wall of Chlorella, probing that rotifer digests Chlorella as a major live food.

• Transactions on Electrical and Electronic Materials
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• 제2권4호
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• pp.30-32
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• 2001

In this paper, a new silicon-on-insulator (SOI) lateral insulated gate bipolar transistor (LIGBT) is proposed to improve the latch-up performance without current path underneath the n$^{+}$ cathode region. The improvement of latch-up performance is verified using the two- dimensional simulator MEDICI and the simulation results on the latch-up current density are 4468 A/cm2 for the proposed LIGBT and 1343 A/$\textrm{cm}^2$ for the conventional LIGBT. The proposed SOI LIGBT exhibits 3 times larger latch-up capability than the conventional SOI LIGBT.T.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2001년도 학술논문발표회
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• pp.64-69
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• 2001

This study is the fundamental report to propose the capability of discarded Bentonite by heat-treatment as concrete mineral admixture. The experiment is performed by flow test of mortar and by compressive strength of 7, 14, 28, 91 days, As a result of experiment about mortar using discarded Bentonite by heat-treatment, in the case of $500^{\circ}C$, $600^{\circ}C$, $700^{\circ}C$, $800^{\circ}C$.60min, compressive strength is superior to the every situation than plain Mortar. Especially, in the case of $700^{\circ}C$.60min, as strength activity index is measured by 109%, it can be applied as concrete mineral admixture. But, flow of Mortar using discarded Bentonite by heat-treatment is decreased about 2.5cm in the case of 30min and about 1.7cm in the case of 60min.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1123-1123
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• 2001

In recent years, a miniature spectrometer has been extensively developed due to the marriage of fiber optics and semiconductor detector array. This type of miniature spectrometer has advantages of low price and robustness due to the capability of mass production and no moving parts are required such as lenses, mirrors and scanning monochromator. These systems are ideal for use in teaching labs, process monitoring and field analyses. A portable near infrared (NIR) system has been developed for qualitative and quantitative analysis. This system includes a tungsten halogen lamp for light source, a fiber optics connected a light source, and a sample module to the microspectrometer, The size of spectrometer can be as small as 2.5 cm x 1.5 cm x 0.1 cm. Wavelength ranges can be chosen as 360-800 nm, 800-1100 nm and 1100-1900 nm depending on the type of detector. The software consists of various tools for multivariate analysis and pattern recognition techniques. To evaluate the system, long and short-term stability, wavelength accuracy, and stray light have been investigated and compared with conventional scanning type NIR spectrometer. This developed system can be sufficiently used for quantitative and qualitative analysis for various samples such as agricultural product, herbal medicine, food, petroleum, and pharmaceuticals, etc.

• Journal of Biosystems Engineering
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• 제26권4호
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• pp.331-336
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• 2001

This study was to develop a kerosene flame weeder. An air compressor was driven though the PTO of a tractor to provide necessary air for fuel combustion and proper pressure to supply fuel from fuel tank to the nozzle. It was found that the flame was extinguished very easily by wind and vibration of the tractor. This trouble could be solved by attaching a burner cap, which is a modified venturi tube, at the end of the nozzle. The constructed flame weeder was tested for the weeding capability in the prepared field. Weed extinction rate and weight decrease rate were analysed. Measured maximum flame temperature was 1,121$\^{C}$ when the fuel consumption was 13.41 kg/h and fuel supply pressure was 88.2 kPa. The maximum temperature occurred at 20cm from the front end the burner, and it decreased to 46$\^{C}$ as the distance increased to 110cm. The flame length of up to 70cm, where the flame temperature was higher than 372$\^{C}$, would be used for weeding purpose. Weed extinction rate and weight decreasing rate increased as the fuel consumption increased. The flame weeder was evaluated to be a practical weeder through improvement as the weed extinction rate and weight decrease rate were analysed to be 75% and 85%, respectively when the fuel consumption was 116.87kg/ha.

• 한국전기전자재료학회논문지
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• 제26권11호
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• pp.785-789
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• 2013

Silicon Carbide (SiC) is the material with the wide band-gap (3.26 eV), high critical electric field (~2.3 MV/cm), and high bulk electron mobility (~900 $cm^2/Vs$). These electronic properties allow attractive features, such as high breakdown voltage, high-speed switching capability, and high temperature operation compared to Si devices. In general, device design has a significant effect on the switching and electrical characteristics. It is known that in this paper, we demonstrated that the switching performance and breakdown voltage of IGBT is dependent with doping concentration of p-base region and drift layer by using 2-D simulations. As a result, electrical characteristics of SiC-IGBT deivce is higher breakdown voltage ($V_B$= 1,600 V), lower on-resistance ($R_{on}$= 0.43 $m{\Omega}{\cdot}cm^2$) than Si-IGBT. Also, we determined that processing time and cost is reduced by the depth of n-drift region of IGBT was reduced.

• Bulletin of the Korean Chemical Society
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• 제9권3호
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• pp.137-143
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• 1988

We have investigated the infrared spectra for carbon monoxide chemisorbed on silica supported ruthenium with and without potassium coating within the frequency range of 1800-2200 $cm^{-1}$ at various ruthenium concentrations and CO pressures. For the system without potassium coating, three bands were observed in the infrared spectra when CO was adsorbed on both the reduced and oxidized form of supported ruthenium. However, the relative intensities of these three bands were found to have no interdependence. Therefore, we have assigned each of these bands as arising from the CO stretching vibration for carbon monoxide molecules adsorbed on the Ru sites of different nature. On coating with potassium, the 2030 $cm^{-1}$ band observed for the system without potassium coating was found to suffer red shift by 10-30 $cm^{-1}$ and we conclude that this bathochromic shift is caused by enhancement in the capability of back donation of electrons from the metal atom to the antibonding ${\pi}{\ast}$ orbitals of CO due to the presence of potassium.