• 한국세라믹학회지
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• 제19권1호
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• pp.19-23
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• 1982

The technique to determine the components in the supersulphated slag cement is discussed by several selective extraction analyses. Accordingly, the rate of hydration reaction of supersulphated slag cement could be quantitatively measured by the following 3 kinds of the selective extraction analyses. (1) Determination of unreacted slag - a salicylic acid, acetone.methanol solution (2) Determination of free $CaSO_4$ - a half saturated lime water (3) Determination of free $Ca(OH)_2$ - glycerine.alcohol solution

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.643-646
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• 1999

In this paper, we propose a feature extraction method based on Bhattacharyya distance for multiclass problems. The Bhattacharyya distance provides a valuable information in determining the effectiveness of a feature set and has been used as separability measure for feature selection. Recently, a feature extraction algorithm hat been proposed for two normally distributed classes based on Bhattacharyya distance. In this paper, we propose to expand the previous approach to multiclass cases. Experiment results show that the proposed method compares favorably with the conventional methods.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1991년도 추계종합학술발표회논문집
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• pp.77-80
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• 1991

This paper proposes a new feature extraction method which is effectively used in character recognition, and validate the effectiveness through various computational methods for similiarity degree. To get feature vectors used in this method, Hough transform is applied to character image, which is used for edge extraction in image processing. By that transformation technique, strokes could be extracted and feature vectors constructed suitably. The characteristic of this method is solving the difficulties in stroke extraction through transform space analysis, which is induced by noise and blurring, and representing high recognition rate 99.3% within 10 candidates in relative low dimension.

• 한국자원식물학회지
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• 제11권1호
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• pp.60-63
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• 1998

For the purposed of improving the utilization of natural chemical pigment, carthamin, of Carthamus tinctorius, the effective extraction methods on this compound were pursued in the present study. The best solvent for the extraction was found to be the 1 %(v/v) NaOH solution, at 25 hours. In addition, more carthamin was extracted flowers from main stem than fromb-ranches . The carthamin content of Korean local safflower was shown to be higher than that of Japanese variety used for medicinal uses.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.884-892
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• 2020

Corticosterone is known as a biological stress index in many species including birds. Feather corticosterone concentration (FCC) has increasingly been used as a measure for chronic stress status in broiler chickens. As sample preparation is the first step of analytical process, different techniques of feather matrix disruption need to be validated for obtaining better result in analysing corticosterone extraction. The current study was a validation of pulverizing the feather by bead beater (BB) and surgical scissors (SS) processing prior to corticosterone extraction in feather of broiler chickens. The type of feather processing prior to the hormone extraction may alter the final output. Thereby, finding a standard method according to laboratory facilities is pivotal. This study carried out to determine the effects of feather pulverization methods on the extraction amount of corticosterone in broiler chickens. Feathers were sampled from four weeks old Ross 308 broiler chickens (n = 12 birds). All broiler chickens were kept under the same environmental condition and had access to feed and water. Feather samples were assigned to one of the following processing methods 1) using a BB for pulverizing and 2) using a SS for chopping into tiny pieces. Each sample was duplicated into two wells during enzyme immunoassay (EIA) analysis to improve the accuracy of the obtained data. The results showed lower standard errors and constant output of FCC by using the BB method compared with the SS method. Overall comparison of FCC showed a significantly higher (p < 0.001) amount of the FCC in the BB compared with the SS. Overall, using the BB method is recommended over the SS method for feather processing due to the ability to homogenize a large number of samples simultaneously, ease of use and greater extraction of feather corticosterone.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.391-407
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• 2023

This article provides a survey of wet (aqueous) methods for recovery, separation, and purification of uranium from fission products in carbonate solutions during the reprocessing of spent nuclear fuel and methods for removal of radionuclides from alkaline radioactive waste. The main methods such as selective direct precipitation, ion exchange, and solvent extraction are considered. These methods were compared and evaluated for reprocessing of spent nuclear fuel in carbonate media according to novel alternative non-acidic methods and for treatment processes of alkaline radioactive waste.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.701-704
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• 2001

유자과피의 향기성분 중 대부분을 차지하는 limonene은 추출물의 함량을 결정하는데 많은 영향을 준다. 일반적으로 Citrus속의 과실류의 향기 성분들 중 가장 많이 함유되어 있는 limonene의 경우 초임계 이산화탄소에 대한 용해도는 압력 140${\sim}$150 bar, 온도 $35{\sim}40^{\circ}C$일 때 최대이고 유자 또한 다량의 limonene을 함유한 과실류로서 초임계 이산화탄소 압력 2000 psi와 온도 $40^{\circ}C$에서 향기성분 중 limonene의 추출율이 향상되어 함량이 786.6088 mg/g으로 최대로 나타났다.

• 자연과학논문집
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• 제5권2호
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• pp.63-73
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• 1992

There are many methods of obtaining butadiene described in the literature. In the america it is produced largely from petroleum gases, i.e., by catalytic dehydrogenation of butene of butene-butane mixtures. Butadiene can be recovered from the $C_4$ residue of an olefin plant by distilling off a fraction containing most of the butadiene, catalytically hydrogenating the higher acetylenes to olefins and separating the product from other olefins and isobutane by extraction. Also it can be obtained by cracking naphtha and light oil. Among the individual dienes of commercial importance, 1, 3-butadiene is of first importance. It is used primarily for the production of polymers.In the present paper, it was investigated for a effect of the formation and the growth inhibition of popped corn polymer in butadiene extraction unit. As a result of study, inhibitors, $NaNO_2$ and TBC were good effective for inhibition of the formation and growth in popcorn polymer. The rational formula of popcorn polymer obtained was $(C_4H_6)_x$.

• 한국정보처리학회논문지
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• 제1권3호
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• pp.311-318
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• 1994

시각신경계의 특정추출 기구인 수용영역 즉, RF(Receptive Field)모델을 이용하여 한자의 획의 분리 및 추출에 관한 방법을 제안한다. 한자의 복잡한 정보에 대한 분리 추출과 데이터베이스화 등은 더욱 명백한 처리과정을 필요로하고 있다. 본 기법의 특 징은 망막과 대뇌 시각영역의 특징추출 기구인 수용영역을 모델링 하였고 신경세포 입력 방식에 따라 국소적인 처리에서 얻어진 정보를 대국적인 처리로 통합 추출하는 것으로서 그 기능성과 유효성을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.139-142
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• 2013

A study was carried out to evaluate the solid phase micro-extraction (SPME) for formaldehyde emission analysis of uncoated plywood. In SPME, formaldehyde was on-fiber derivatized through headspace extraction and analyzed by gas chromatography coupled with mass spectrometry (GC/MS). The SPME was compared with desiccators (DC-JAS 233), small-scale chamber (SSC-ASTM D6007) and liquid-liquid extraction (LLE-EPA 556) methods which were performed in accordance with their respective standards. Compared to SSC (RSD 4.3%) and LLE (RSD 5.0%), the SPME method showed better repeatability (RSD 1.8%) and not much difference from DC (RSD 1.4%). The SPME has proven to be highly precise (at 95% confidence level) with better recovery (REC 102%). Validation of the SPME method for formaldehyde quantitative analysis was evidenced. In addition, the SPME by air sampling directly from plywood specimens (SPME-W) correlated best with DC ($r^2$ = 0.983), followed by LLE ($r^2$ = 0.950) and SSC ($r^2$ = 0.935).