• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.301-306
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• 2009

This paper describes the design and fabrication of 16$\times$16 microbolometer infrared focal plane arrays based on iMEMS technology. Amorphous silicon was used for infrared-sensitive material, and it showed the resistance of 18 Mohm and the temperature coefficient of resistivity of -2.4 %. The fabricated sensors exhibited responsivity of 78 kV/W and thermal time constant of 8.0 msec at a bias voltage of 0.5 V. The array performances had satisfactory uniformity less than 5 % within one-sigma. Also, 1/f noise of pixel was measured and the noise factor of $6\times10^{-11}$ was extracted. Finally, we obtained detectivity of $1.27\times10^9cmHz^{0.5}/W$ and noise equivalent temperature difference of 200 mK at a frame rate of 30 Hz.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.159-166
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• 2014

The study is conducted on the subject of optimization of components sizing for series hybrid electric propulsion systems. The components sizing of series type hybrid system is very important because each component of series type is larger than the corresponding component of the parallel type or series-parallel type. If the components sizing is greater or less than what is required to this system, the performance of the system is getting worse. The methodology for the sizing of a driving motor is introduced based on the foundation of determined system configuration and performance target. And the sizing of an engine/generator and a battery is achieved based on simulation results using Dynamic Programming. It is possible to find the optimal sizing of these components by comparing fuel efficiency of hybrid electric propulsion system for 8 driving cycles.

• The Korean Journal of Food And Nutrition
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• v.35 no.3
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• pp.185-192
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• 2022

This study investigated the volatile flavor components of the essential oil from Chrysanthemum coronarium var. spatiosumBailey. The essential oil obtained from the aerial parts of the plant by the hydrodistillation extraction method was analyzed by gas chromatography and gas chromatography-mass spectrometry. One hundred and one (99.11%) volatile flavor components were identified in the essential oil from the Chrysanthemum coronarium var. spatiosum Bailey. The major compounds were hexanedioic acid, bis(2-ethylhexyl) ester (12.45%), 6.10.14-trimethyl-2-pentadecanone (7.94%), 1-(phenylethynyl)-1-cyclohexanol (6.34%), α-farnesene (5.55%), phytol (4.99%), and α-caryophyllene (4.39%). When the volatile flavor components of Chrysanthemum coronarium var. spatiosum Bailey were classified by functional group, the content was high in the order of hydrocarbons, alcohols, esters, ketones, aldehydes, and phthalides. Sesquiterpene hydrocarbons were the most common hydrocarbons, mainly due to α-farnesene and α-caryophyllene. Among the alcohols, the content of aliphatic alcohols was significantly higher, mainly due to 1-(phenylethnyl)-1-cyclohexanol (6.34%) and phytol (4.99%). The analysis of the volatile flavor components of Chrysanthemum coronarium var. spatiosum Bailey in this study will provide useful information to consumers when purchasing food and to industries using fragrance ingredients.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1719-1723
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• 2009

The LiFeP$O_4$ powder was synthesized by using the solid state reaction method with Fe($C_2O_4){\cdot}2H_2O,\;(NH_4)_2HPO_4,\;Li_2CO_3$, and chitosan as a carbon precursor material for a cathode of a lithium-ion battery. The chitosan added LiFePO4 powder was calcined at 350 ${^{\circ}C}$ for 5 hours and then 800 ${^{\circ}C}$ for 12 hours for the calcination. Then we calcined again at 800 ${^{\circ}C}$ for 12 hours. We characterized the synthesized compounds via the crystallinity, the valence states of iron ions, and their shapes using TGA, XRD, SEM, TEM, and XPS. We found that the synthesized powders were carbon-coated using TEM images and the iron ion is substituted from 3+ to 2+ through XPS measurements. We observed voltage characteristics and initial charge-discharge characteristics according to the C rate in LiFeP$O_4$ batteries. The obtained initial specific capacity of the chitosan added LiFeP$O_4$ powder is 110 mAh/g, which is much larger than that of LiFeP$O_4$ only powder.

• ETRI Journal
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• v.35 no.4
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• pp.559-565
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• 2013

In this work, we develop a simulation method to predict a two-dimensional luminance distribution method using a circuitry simulation. Based on the simulation results, we successfully fabricate large area ($90mm{\times}90mm$) transparent organic light-emitting diode panels with high luminance uniformity.

• Journal of Drive and Control
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• v.13 no.1
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• pp.10-17
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• 2016

e-4WD(Electric-4WD) system is a 4WD(4-Wheel Drive) System that can transform a car into a Hybrid System. e-4WD consists of a Motor, Inverter, Speed reducer and Clutch. The Motor, Speed reducer and Clutch are installed on the rear sub-frame as a chassis module type. The inverter is installed separately. Compared to a mechanical 4WD, the e-4WD system has many advantages. For example, the reduced number of drivetrain components makes better use of the space. Driving with a motor only at low speed improves fuel economy and reduces exhaust gas. Engine downsizing is available because the motor assists the engine. The performance of a conventional HEV(Hybrid Electric Vehicle) system can also be maintained. This paper proposes the specifications of components and the control logic for an e-4WD System. And the effect of the e-4WD system is proven using a test vehicle equipped with components under various test conditions.

• East Asian mathematical journal
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• v.34 no.4
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• pp.451-462
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• 2018

This study analyzed the learning components of the web-based adaptive math learning programs in order to develop adaptive math learning program using artificial intelligence. The components of the web-based adaptive math learning program set for analysis are classified into learning process presentation, concept learning, problem presentation, problem solving process, and learning result processing then analyzed three programs. As a result of analysis, the typical characteristic of components is that it uses a method of repeatedly presenting the same type of problem in order to learn one concept.

• The Korean Journal of Food And Nutrition
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• v.12 no.4
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• pp.375-379
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• 1999

Volatile components of Cornsilk(Zea mays L.) were isolated by purge and trap headspace method and were analyzed by GC and GC/MSD. A total of 44 components were identified in the cornsilk volatile coponents including 9 alcohols 7 aldehydes and ketones 14 terpenes and terpene alcohols 3 pyrazines 5 hydrocarbons and 6 miscellaneous components. The major components were 2-propanol(8.08%) pen-tanol(1.82%) hexanol(2.86%) hexanal(3.68%) heptanal(7.40%) nonanal(7.93%) decanal (2.04%) $\alpha$-copaene(2.20%) limonene(1.68%) $\alpha$-selinene(1.03%) $\beta$-selinene(1.03%)

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.4
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• pp.477-481
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• 1998

Colored components in black tea were extracted, freeze-dried, and analysed to investigate the possibility using as a natural dye. Fractionation of the colored components was carried out by gel permeation chromatography. The colored components in black tea were elected into seven fractions. Each fraction was analyzed by UV spectrophotometer. The early fluted fractions 1-4 did not show any absorption peaks in 320-700 nm and showed the increase in absorption as it approaches to short wavelength and are considered as highly polymerized colored substances. Fractions 5-6 showed tar at 350 m and are considered as thearubigins. Fraction 7 showed absorption peaks at 376 nm and 456 nm and is considered as theaflavin. IR spectra of each fraction show: Strong C=0 stretching band at 1650 cm-1 appears in fractions 1-4, but not in fractions 5-7. Strong C=0 stretching band at 1700 cm-L appears in fraction 3-7. C=0 stretching band at 1610 cm-1 appears as a shoulder in fraction 4 and progressively changes into strong peak in fraction 5-7. From these results, it is assumed that colored components in black tea consist of polyphenolic substances having different molecular weight which were formed during tea manufacturing process. The colorants from black tea infusion were applied to silk, wool, cotton and nylon fabrics. Black tea colorants showed high affinity to wool, silk and nylon, but very low affinity to cotton fabrics.

• Journal of Ginseng Research
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• v.20 no.1
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• pp.42-48
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• 1996

This study was carried out to determine the differences of essential oil components among Korean, Chinese and Japanese red ginseng, and Korean white ginseng (Panax ginseng C.A Mayer) , American and Canadian ginseng (P. Quinquefolium), and sanchi ginseng (P notoginseng). The steam distilled oils of these ginsengs were analyzed by GC and GC-MS, and 22 sesquiterpenes, 8 sesquiterpene alcohols, 8 monoterpenes, 5 aldehydes, 4 esters, 3 acids, 2 alcohols and 5 miscellaneous components were identified. The major oil components of Korean, Chinese and Japanese red ginseng were $\beta$-panasinsene, $\beta$-caryophyllene, $\alpha$-panasinsene, $\alpha$-neoclovene, selina-4,11-diane, bicyclo-ger-macrene and spathulenol. The contents of $\beta$-panasinsene, $\alpha$-neoclovene, $\alpha$-basabolene and spathulenol were higher in Korean red ginseng than Chinese and Japanese red ginseng. The contents of $\alpha$-cubebene, selina-4,11-diene and ledol were higher in Chinese red ginseng than Korean and Japanese red ginseng, but those of selina-4,11-diene and spathulenol were lower in Japanese red ginseng than Korean or Chinese red ginseng. On the other hand, the GC patterns of the oils from American, Canadian and sanchi ginseng were different from that of Korean white ginseng.