• ETRI Journal
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• 제27권5호
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• pp.585-594
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• 2005

A small electronic nose (E-Nose) system has been developed using an 8-channel vapor detection array and personal digital assistant (PDA). The sensor array chip, integrated on a single microheater-embedded polyimide substrate, was made of carbon black-polymer composites with different kinds of polymers and plasticizers. We have successfully classified various volatile organic compounds such as methanol, ethanol, i-propanol, benzene, toluene, n-hexane, n-heptane, and c-hexane with the aid of the sensor array chip, and have evaluated the resolution factors among them, quantitatively. To achieve a PDA-based E-Nose system, we have also elaborated small sensor-interrogating circuits, simple vapor delivery components, and data acquisition and processing programs. As preliminary results show, the miniaturized E-Nose system has demonstrated the identification of essential oils extracted from mint, lavender, and eucalyptus plants.

• Journal of electromagnetic engineering and science
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• 제16권3호
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• pp.182-190
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• 2016

The problem of resolution in antenna ground-penetrating radar (GPR) is very important for the investigation and detection of buried targets. We should solve this problem with software or a numeric method. The purposes of this paper are the modelling and simulation resolution of antenna radar GPR using three antennas, arrays (as in the software REFLEXW), the antenna dipole (as in GprMax2D), and a bow-tie antenna (as in the experimental results). The numeric code has been developed for study resolution antennas by scattered electric fields in mode B-scan. Three frequency antennas (500, 800, and 1,000 MHz) have been used in this work. The simulation results were compared with experimental results obtained by Rial and colleagues under the same conditions.

• 한국식품영양과학회지
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• 제29권6호
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• pp.1123-1126
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• 2000

수증기 증류법으로부터 얻은 배초향(Agastache rugo-sa, Labiatae)의 정유는 부패균을 포함하는 수종의 미생물에 대하여 현저한 항균활성을 나타내었다. 배초향의 유효성분을 확인하기 위하여 정유성분을 GC-MS로 분석한 결과 GC chromatogram에서 얻은 각 피크의 reten-tion time 및 mass spectral data 의표준물질과의 비교에 의해서 isomenthone, methone, dihydrocarvone, anetho-le, vanillin, eugenol, methyleugenol, $\beta$-caryophyllene, $\beta$-caryophyllene oxide 등의 정유성분이 확인되었다. 이 연구에서 밝혀진 여러 성분들의 항균 활성은 잘 알려져 있으므로 이들이 유효성분으로 추측된다. 또한 Korean mint로 세계적으로 알려져 있는 배초향의 정유는 식품 방부제로서 적합할 것으로 생각된다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.311-314
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• 2009

This paper presents the characteristics of grounding impedance of counterpoises buried at various soil structures. Grounding impedance measurements were made by the Fall-of-Potential method. The experiments were carried out in 50 m counterpoise of 25 $mm^2$ buried at a depth of 0.5 m. The test current was injected by the impulse generator having the front time of $1{\sim}60{\mu}s$. As a result, the soil structures greatly influences on the grounding impedance characteristics of counterpoise. The transient grounding impedances strongly depend on the injection mint and the front time of impulse current.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.358-358
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• 2006

The graft copolymerization of methyl methacrylate (MMA), butyl acrylate (BA) and acrylamide (AAm) onto oil palm empty fruit bunch (OPEFB) fiber were successfully carried out in aqueous solution using $H_{2}O_{2}/Fe^{2+}$ as initiator. For all monomers the percentage of grafting increases with the amount of monomer and can be controlled by setting the appropriate reaction conditions. The optimum reaction period were found to be 120 minutes for all monomers whereas the optimum temperature and the amount of initiator needed for grafting depend on the type of the monomer used. The mechanisms of grafting vinyl monomer onto OPEFB were proposed. The grafted products were characterized by gravimetric analysis, FTIR and SEM.

• 생약학회지
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• 제47권2호
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• pp.192-196
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• 2016

The herb of Agastache rugosa (Lamiaceae) called Korean mint as a spice or Agastache Herba as a crude drug is known to contain highly fragrant volatile substances. This research aimed to establish the quantitative gas chromatography (GC) method on the essential oil of A. rugosa using the three standard compounds, estragole, methyleugenol, pulegone, and to find whether the essential oil has anti-Alzheimer's activity. The GC quantification method was established by determining the linearity of calibration curve ($R^2$), linear range, and both limit-of-detection (LOD) and limit-of-quantification (LOQ). The $IC_{50}$ of the essential oil on the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were determined to be $69.06{\pm}0.26$ and $76.71{\pm}0.58{\mu}g/ml$, respectively.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2012년도 심포지엄 및 춘계학술발표회
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• pp.277-278
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• 2012

• Current Applied Physics
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• 제18권11호
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• pp.1399-1402
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• 2018

Nanorod films of cobalt oxide ($Co_3O_4$) have been grown by a unique oblique angle deposition (OAD) technique in an e-beam evaporator for supercapacitor electrode applications. This technique offers a non-chemical route to achieve large aspect ratio nanorods. The fabricated electrodes at OAD $80^{\circ}$ exhibited a specific capacitance of 2875 F/g. The electrochemically active surface area was $1397cm^{-2}$, estimated from the non-Faradaic capacitive current region. Peak energy and power densities obtained for $Co_3O_4$ nanorods were 57.7 Wh/Kg and 9.5 kW/kg, respectively. The $Co_3O_4$ nanorod electrode showed a good endurance of 2000 charge-discharge cycles with 62% retention. The OAD approach for fabricating supercapacitor nanostructured electrodes can be exploited for the fabrication of a broad range of metal oxide materials.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.952-961
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• 2003

In the first part of the study, rates of estrus occurrence and success of A.I. service in the Thai-native and Friesian crossbred, and purebred Friesian cows fed in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand were traced monthly throughout a year. An electric fan and a water sprinkler cooled the stall for the purebred cows during the hot season (March-September). Both rates in pure Friesians were at their highest in the cold-dry season (October- February), but they decreased steadily during the hot-dry season (March-May) and were at their lowest in the hot-wet season (June-September). Seasonal change of a similar pattern was observed in the incidence of estrus, but not in the success rate of insemination in the crossbred cows. By the use of reproductive data, compiled in the same institute, on the 75 % cross- and purebred Friesian cows, and climatological data in Chiang Mai district, effects of ambient temperature and humidity on the reproductive traits of cows were examined by regression analysis in the second half of the study. Significant relationships in the crossbred, expressed by positive-linear and parabola regressions, were found between reproductive parameters such as days to the first estrus (DTFE), A.I. service (DTFAI), and conception, the number of A.I. services required for conception and some climatic factors. However, regarding this, no consistent or intelligible results were obtained in purebred cows, perhaps because electric fans and water sprinklers were used for this breed in the hot season. Among climatic factors examined, the minimum temperature (MINT) in early lactation affected reproductive activity most conspicuously. As the temperature during one or two months prior to the first estrus and A.I. service rose, DTFE and DTFAI steadily became longer, although, when MINT depleted below $17-18^{\circ}C$, the reproductive interval tended to be prolonged again on some occasions. The maximum temperature also affected DTFE and DTFAI, but only in limited conditions. The effect of humidity was not clear, although the inverse relationship between DTFE and minimum humidity during 2 months before the first estrus in the crossbred seemed to be significant. Failure to detect any definite effect of climate on the reproductive traits of pure Friesians seemed to indicate that forced ventilation by electric fans and water sprinklers were effective enough to protect the reproductive ability of this breed from the adverse effects of a hot climate.

• 한국컴퓨터산업학회논문지
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• 제4권4호
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• pp.533-546
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• 2003

기존의 대금지불 방법들은 개별 정보들과 같은 소액 상품의 결제 수단으로는 부적절하다. 이유는 상품의 가치보다 결제 수단을 운영하는데 들어가는 비용이 더 크기 때문에 경제성이 전혀 없기 때문이다. 그리하여, 인터넷 상에서 활발한 거래가 예견되는 초소액의 정보 상품들을 경제적으로 처리할 수 있는 새로운 대금결제 방식이 요구된다. 최근에 제안된 몇몇 소액지불 시스템들로는 "Millicent", "PayWord", "MicroMint", "iKP" 등이 있다. 이들 각각은 나금대로의 방식으로 안전성과 소비용화를 추구하고 있다. 그러나, 이들 방식들은 핵심 메커니즘의 소비용화와 적절한 보안의 만족 등에는 문제가 없었으나 "계좌(account)의 관리"와 "지불 화폐의 집중,관리" 에는 큰 문제점을 가지고 있다. 소액대금결제 시스템에서는 계좌 관리의 복잡성과 지불 값들의 집중의 효율적인 해결이 가장 먼저 고려되어지고 우선시 되어져야 할 항목이다. 그리하여, 본 논문은 PayWord시스템을 바탕으로 적절한 보안 만족, 운영 비용의 저렴화를 이룰 수 있게 하는 핵심 메커니즘의 사용, 불필요한 계좌의 이중 사용 배제, 지불 화폐 값들의 집중관리 해결 등을 만족시켜줄 수 있는 효율적인 소액대금결제 시스템인 PayHash를 설계, 구현하였다.의 집중관리 해결 등을 만족시켜줄 수 있는 효율적인 소액대금결제 시스템인 PayHash를 설계, 구현하였다.