• 한국식품저장유통학회지
• /
• 제15권6호
• /
• pp.840-846
• /
• 2008

포도씨의 총 카테킨 함량과 추출물의 항산화성을 극대화하기 위한 마이크로웨이브 추출조건의 최적화를 시도하였다. 중심합성계획에 따라 추출조건(microwave power $0{\sim}120\;W$, 에탄올 농도 $0{\sim}100%$, 추출시간 $1{\sim}5\;min$)을 설계하고, 종속변수로서 추출물의 수율, 카테킨 함량 및 전자공여능을 회귀 분석함으로써 최적 추출조건을 예측하였다. 모든 회귀식의 $R^2$는 0.9 이상으로 1% 수준에서 유의성이 인정되었다. 총 카테킨 함량의 최대 추출 값은 434.16 mg%로 예측되었으며, 추출조건은 microwave power 122.76 W, 에탄올 농도 42.88%, 추출시간 4.67 min으로 나타났다. 추출물에 대한 세 가지 종속변수의 극대 값을 얻기 위한 추출조건 범위는 $75{\sim}150\;W$, $40{\sim}60%$ 및 $3.5{\sim}5.0\;min$이었다. 이상의 예측 값(총 추출수율 6.72%, 총 카테킨 함량 408.65mg%, 전자공여능 83.33%)은 실제 값과 유의적인 차이가 없었으며, 최적화된 마이크로웨이브 추출법(112.5 W, 50% 에탄올, 4.2분)은 현행추출법 (80% 에탄올, $60^{\circ}C$, 3시간, 150 rpm)에 비해 추출효율이 우수하였다.

• 한국식품위생안전성학회지
• /
• 제14권4호
• /
• pp.365-371
• /
• 1999

인삼시료에 있는 quintozene, tolclofos-methyl 그리고 procymidone 등의 농약성분을 추출하기 위한 방법으로서 microwave를 이용할 수 있을 지의 여부와 인삼을 가공제품으로 만들기 전에 microwave를 이용하여 잔류농약 성분을 신속히 추출하여 제거시킬 수 있는지 알고자 하였다. 인삼분말 시료에 hexane을 추출용매로 이용한 microwave 추출의 최적 조건은 power 150 watts, 추출시간 2분이었고 그 추출 효율은 Soxhlet으로 7시간 동안 가열 환류 추출한 결과를 지수 100으로 하였을 때 quintozene 100, tolclofos-methyl 92, procymidone 100으로 거의 동일한 수준으로 나타났다. 그리고 microwave 추출법을 사용함으로써 실제 Soxhlet 추출법에서 사용된 용매양의 최소 7배 이상 감소시킬 수 있었고 추출 시간 또한 7시간에서 2분으로 훨씬 단축되었다. 인삼 엑기스 제조 전 잔류농약 성분의 제거 실험에 있어서 45%나 60% ethyl alcohol을 용매로 사용하고 microwave로 power 150 watts 추출시간 2분 이내로 1회 추출하여 quintozene 100%, tolclofos-methyl 69%, procymidone 83%정도의 제거효과를 얻었다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
• /
• pp.915-918
• /
• 2000

In this paper, we propose an efficient feature vector extraction and decision fusion methods for the automatic classification of power system disturbances. Here, FFT and WPT(wavelet packet transform) are und to extract an appropriate feature for classifying power quality disturbances with variable properties. In particular, the WPT can be utilized to develop an adaptable feature extraction algorithm using best basis selection. Furthermore. the extracted feature vectors are applied as input to the decision fusion system which combines the decisions of several classifiers having complementary performances, leading to improvement of the classification performance. Finally, the applicability of the proposed approach is demonstrated using some simulations results obtained by analyzing power quality disturbances data generated by using Matlab.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
• /
• pp.671-674
• /
• 1997

The objective of this paper is to present a new feature-vector extraction method for the automatic detection and classification of power quality(PQ) disturbances, where FIT, DWT(Discrete Wavelet Transform), and Fisher's criterion are utilized to extract an appropriate feature vector. In particular, the proposed classifier consists of three parts: i.e., (i) automatic detection of PQ disturbances, where the wavelet transform and signal power estimation method are utilized to detect each disturbance, (ii) feature vector extraction from the detected disturbance, and (iii) automatic classification, where Multi-Layer Perceptron(MLP) is used to classify each disturbance from the corresponding extracted feature vector. To demonstrate the performance and applicability of the proposed classification algorithm, some test results obtained by analyzing 10-class power quality disturbances are also provided.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.96.5-96
• /
• 2002

This paper describes extraction procedures for the center coordinates of steam generator tubes of Youngkwang nuclear power plant No. 6 unit. The centering coordinates of tubes are needed for monitoring whether ECT probe is exactly inserted into tube or not. However, The tube image tends to have poor contrast because steam generator bowl is sealed. The centering coordinates extraction procedure consists of two steps. The first step is to process the region with high contrast in entire image of steam generator tubes. Using the center points extracted in the first step and the geometry of tubes lined up in regular triangle patterns the centering coordinates of the rest region with low contrast...

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
• /
• pp.79-79
• /
• 2011

The oceans are an untapped resource, capable of making a major contribution to our future energy needs. In the search for a non polluting renewable energy source, there is a push to find an economical way to harness energy from the ocean. Tidal stream is one of ocean energy form that is being investigated as potential source for power generation. Tidal current turbines are therefore designed as conversion machinery to generate power from tidal currents. A study on energy extraction from tidal currents is presented in this paper.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 C
• /
• pp.1030-1032
• /
• 1998

In this paper, an efficient feature vector extraction method and MLP neural network are utilized to automatically detect and classify power quality disturbances, where the proposed classification procedure consists of the following three parts: i.e., (i) PQ disturbance detection using discrete wavelet transform. (ii) feature vector extraction from the detected disturbance. using several methods, such as FFT, DWT, Fisher's criterion. etc.. and (iii) classification of the corresponding type of each PQ disturbance by recognizing the pattern of the extracted feature vector. To demonstrate the performance and, applicability of the proposed classification algorithm. some test results obtained by analyzing 10-class PQ disturbances are also provided.

• Nuclear Engineering and Technology
• /
• 제53권3호
• /
• pp.866-878
• /
• 2021

Procedures play a key role in ensuring safe operation at nuclear power plants (NPPs). Development and maintenance of a large number of procedures reflecting the best knowledge available in all relevant areas is a complex job. This paper introduces a newly developed methodology and the implemented software, called iExtractor, for the extraction of syntactic and semantic information from NPP procedures utilizing natural language processing (NLP)-based technologies. The steps of the iExtractor integrated with sets of rules and an ontology for NPPs are described in detail with examples. Case study results of the iExtractor applied to selected procedures of a U.S. commercial NPP are also introduced. It is shown that the iExtractor can provide overall comprehension of the analyzed procedures and indicate parts of procedures that need improvement. The rich information extracted from procedures could be further utilized as a basis for their enhanced management.

• 한국통신학회논문지
• /
• 제28권9C호
• /
• pp.876-883
• /
• 2003

본 논문에서는 초음파 영상에서 로그 전력 스펙트럼(log power spectrum)을 이용한 장기 인식 알고리듬을 제시한다. 제안한 알고리듬은 크게 특징추출과 특징분류의 두 단계로 구성된다. 특징추출에서는 이동불변의 성질을 가지는 로그 전력 스펙트럼을 이용하여 전처리를 수행한 입력 영상으로부터 장기 조직의 반향(echo of the tissue) 성분을 추출한다. 특징 분류에서는 마하라노비스(Mahalanobis) 거리를 사용하여 입력영상으로부터 추출한 특징벡터와 각 영상 부류의 평균벡터 사이의 유사도를 측정한다. 실제 초음파 영상에 대한 실험결과는 제안된 알고리듬이 전력 스펙트럼(power spectrum)과 유클리드(Euclid) 거리를 이용한 인식 알고리듬보다 최대 30% 향상된 인식률을, 또 가중 큐프런시(weighted quefrency) 복소 켑스트럼(complex cepstrum)을 이용한 알고리듬보다 10∼40% 향상된 인식률을 보여준다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 D
• /
• pp.2307-2309
• /
• 2004

This paper presents a modeling and simulation of a fuzzy controller for maximum power extraction of a grid-connected wind energy conversion system with a link of a rectifier and an inverter. It discusses the maximum power control algorithm for a wind turbine and proposes, in a graphical form, the relationships of wind turbine output, rotor speed, power coefficient, tip-speed ratio with wind speed when the wind turbine is operated under the maximum power control. The control objective is to always extract maximum power from wind and transfer the power to the utility by controlling both the pitch angle of the wind turbine blades and the inverter firing angle. Pitch control method is mechanically complicated, but the control performance is better than that of the stall regulation method. The simulation results performed on MATLAB will show the variation of generator's rotor angle and rotor speed, pitch angle, and generator output.