• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.997-1001
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• 2000

The organic acids in 3 kinds of medicinal herbal extracts were screened and compared each other according to their organic acid contents by an efficient gas chromatographic method. It involves solid-phase extraction of organic acids using Chromosorb P with subsequent conversion to stable tert-butyldimethysilyl derivatives for the direct analysis by capillary column gas chromatography and gas chromatography-mass spectrometry. Total of 24 organic acids were reproducibly identified from 3 kinds of herbal extracts. When the GC profiles were simplified to their retention index spectra, characteristic patterns were obtained for each herb sample. As expected, three kinds of herbal extracts showed three distinct patterns.

• Korean Journal of Community Nutrition
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• v.4 no.1
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• pp.95-102
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• 1999

This study used questionnaires to investigate the safety awareness for imported foods by 365 male and female adults in Taejon. The results of the study were as follow : By factor analysis, the subjects' behaviors and awareness of the imported food was grouped into 3 factors such as 'health and quality factor', 'purchasing factor' and 'contamination factor'. 'Health and quality factor' and 'purchasing factor' were not recognized negatively by the subjects, moreover' contamination factor' was recognized very highly. The subjects' concern and worry about the imported food was also very high. The marital status, education level, nutriton knowledge adn recognition level of contamination by pesticides and heavy metals of foods partially affected the recognitio level of imported foods. The major selection criteria of imported food were distribution period(36.3%), price(28.8%) and purchasing experience(17.3%). The imported food mean discrimination score was 8.4±3.1 out of 13. The worst discriminatio score was red pepper. The subjects' experiences with imported foods selection affected the most instead of education level or nutrition knowledge. The higher discrimination score group more negatively recognized imported food and contamination recognition level was higher whereas the lowerdiscrimination score group more positively recognized the purchasing frequency and with to buy more easily. But both groups desired to reinforce contamination control. The better discrimination score of imported food pooring recognized sanitation concerns(p<0.05), quality(p<0.05), cooking convenience(p<0.01), desire for more variety(p<0.05), and the higher contamination recognition level(p<0.05) and desire to reinforce contamination control(p<0.01).

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.291-296
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• 1984

The lipid composition of domestic and imported beef samples was analyzed and the lipid rancidity and flavor changes during their cooking and storage for 48 hours at $4^{\circ}C$ were investigated. The contents of total lipids and neutral lipids of raw, cooked and cooked-stored samples were higher in domestic beef than in imported beef. During cooking by simmering or roasting and storage for 48 hours at $4^{\circ}C$, the contents of total lipids and phospholipids showed a decreasing tendency in all samples. The results of sensory test for domestic and imported beef samples with two different cooking methods revealed significant differences between domestic and imported in both simmering and roasting. In a palatability test by hedonic scale, no significant difference was observed among roasted samples while a significant difference was observed among simmered samples between cooked domestic and cooked-stored imported beef. The increaase of TBA values in all cooked samples was mild right after cooking whereas it was rapid in cooked-stored samples. As TBA values increased, sensory scores decreased in all samples.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1112-1120
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• 2017

Petroleum products are composed of various types of hydrocarbon compounds. Like other types of liquids, they presented the variation of density and volume according to temperature change. The method of measuring the density of petroleum products in a liquid phase is based on experimental data obtained mainly for each fractionally distilled petroleum product. In this study, the density and volume changes of kerosene and automotive diesel according to temperature change were measured and the property of change were analyzed. The conversion values were calculated using the density volume conversion table proposed by international standard ASTM. In addition, we analyzed the differences between the reference values and the measured values for the temperature changes specified in the domestic metering law.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1596-1603
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• 2007

In this paper, we experimented by three kind of method for feature parameter, training method and recognition algorithm of most suitable for speech recognition system and considered. We decided speech recognition system of most suitable through two kind of experiment after we make speech recognizer. First, we did an experiment about three kind of feature parameter to evaluate recognition performance of it in speech recognizer using existent MFCC and MFCC new feature parameter that change characteristic space using PCA and ICA. Second, we experimented recognition performance or HMM, SVM and RVM by studying data number. By an experiment until now, feature parameter by ICA showed performance improvement of average 1.5% than MFCC by high linear discrimination from characteristic space. RVM showed performance improvement of maximum 3.25% than HMM in an experiment by decrease of studying data. As such result, effective method for speech recognition system to propose in this paper derives feature parameters using ICA and un recognition using RVM.

• Korean Journal of Remote Sensing
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• v.15 no.3
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• pp.183-194
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• 1999

The Brightness, color and texture included in a multispectral satellite data are used as important factors to analyze and to apply the image data for a proper use. One of the most significant process in the satellite data analysis using texture or color information is to extract features effectively expressing the information of original image. It was described in this paper that six features were introduced to extract useful features from the analysis of the satellite data, and also a classification network using the back-propagation neural network was constructed to evaluate the classification ability of each vector feature in SPOT imagery. The vector features were adopted from the training set selection for the interesting region, and applied to the classification process. The classification results showed that each vector feature contained many merits and demerits depending on each vector's characteristics, and each vector had compatible classification ability. Therefore, it is expected that the color and texture features are effectively used not only in the classification process of satellite imagery, but in various image classification and application fields.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.459-459
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• 2017

본 연구에서는 순물소모량 개념의 농업용수 수요량 추정방법을 적용하여 기후변화에 따른 제주도의 미래 수요량 변화를 추정 분석하였다. 지하수를 주 수원으로 하고 관정에 의한 밭작물 위주의 작물재배와, 일정 규모 이상의 강우시에만 유출이 발생하며, 유출량의 대부분이 지하수로 침투되는 물순환 특성 등을 고려할 수 있는 제주도 지역에 적합한 순물소모량 산정방법을 적용하였다. 순물소모량 산정에 필요한 실제증발산량 및 잠재증발산량 등은 유역모형인 SWAT을 이용하여 산정하였다. SWAT 모형의 구동에 필요한 미래 기후자료는 10개의 대표적인 대순환모델(General Circulation Model, GCM) 결과로부터 상세화(Downscaling) 기법을 통해 적용하였으며, RCP 4.5와 RCP 8.5 시나리오를 중심으로 미래 기후변화에 따른 영향을 분석하였다. 미래(2010-2099)의 수문성분별 변화를 살펴본 결과, 연도별 증감과 GCM 모델별 차이는 있으나, 평균적으로 강수량, 잠재증발산량, 실제증발산량, 함양량 등이 점차 증가하는 것으로 나타났으며, RCP 4.5보다는 RCP 8.5 시나리오에서 증가현상이 좀 더 크게 나타났다. 순물소모량 또한 2010년에 비해 2099년을 기준으로 약 100~200mm 정도 증가하는 것으로 나타났으며, RCP 8.5 시나리오에서 증가폭이 크게 나타났다. 그러나 이는 자연적인 기후변화에 따른 단위면적당 순물소모량으로서, 인위적인 요인인 농업형태의 변화(관개면적의 증감, 작물품종의 변화, 인위적 용수절감 등)에 따라 실제 지역별 농업용수 수요량은 다른 경향을 나타낼 수도 있다. 특히 농업용수는 계절별, 지역별 편차가 크게 나타나므로, 자연적 조건에 의한 가용수자원량과 지역별 공급시설에 의한 용수공급량 및 수요예측량의 상호분석을 통해 안정적 물수급을 위한 대응책 마련이 필요할 것으로 판단된다.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.9
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• pp.373-378
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• 2019

Since many programming sources are open online, problems with reckless plagiarism and copyrights are occurring. Among them, source codes produced by repeated authors may have unique fingerprints due to their programming characteristics. This paper identifies each author by learning from a Google Code Jam program source using deep neural network. In this case, the original creator's source is to be vectored using a pre-processing instrument such as predictive-based vector or frequency-based approach, TF-IDF, etc. and to identify the original program source by learning by using a deep neural network. In addition a language-independent learning system was constructed using a pre-processing machine and compared with other existing learning methods. Among them, models using TF-IDF and in-depth neural networks were found to perform better than those using other pre-processing or other learning methods.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.555-561
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• 2012

The Hilbert Huang Transform (HHT) technigue with Empirical Mode Decomposition (EMD) is one of the time-frequency domain analysis methods and it has several advantages such that analyzing non-stationary and nonlinear signal is possible. However, there are shortcomings in detecting near-range of frequencies and added noise signals. In this paper, to analyze characteristics of each method, HHT and Short-Time Fourier Transform (STFT) effective in dealing with stationary signals are compared. And with thermoacoustic instabilities signals from a Rijke tube test, HHT and the improved HHT with Ensemble Empirical Mode Decomposition (EEMD) are compared. The results show that the improved HHT is more appropriate than the original HHT due to the relative insensitivity to noise. Therefore it will result in more accurate analysis.

• Korean Journal of Optics and Photonics
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• v.3 no.1
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• pp.27-36
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• 1992

Frequency modulation spectroscopy of the super-cavity, of which finesse is app. 40,000 has been demonstrated by using a sigle mode He-Ne laser. In-phase and quardrature components of frequency modulation signals (FM signal) were obtained by using the 1.5 MHz-driven-electrooptic phase modulator. The vector locus of the FM signa in the phase space, which is consisted of in-phase and quardrature components of the FM signal, was observed and analyzed for the dependence of FM signal upon the phase of the reference signal of a phase-sensitive-detector. According to rotating the phase of the reference signal, the vector locus was observed to rotate with the same phase angle as the reference signal. The in-phase component of the FM signals will be used to stabilize the frequency of the He-Ne laser to the resonant frequency of the super-cavity.