• Title/Summary/Keyword: elimination method

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Analysis of Trench Coat Design by the Checklist Method (체크리스트법에 의한 트렌치코트 디자인 분석)

  • Kim, Min Chae;Lim, Ji Young
    • Journal of the Korean Society of Costume
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    • v.62 no.7
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    • pp.97-116
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    • 2012
  • The purpose of this study is to analyze the trench coat designs shown in the latest collection by using a checklist method among many fashion design idea methods and then investigate the trend of trench coat design in multilateral directions. As for the research method, 1,307 photos selected from the photos of women's trench coats publicized from 2006 until 2011 were used for the analysis and then a frequency analysis was conducted. As a result, the types of checklist methods shown in trench coats included modification type, elimination type, conversion type, combination type, minimization type, addition type, and magnification type. In the modification type, the modification of color to the back side stood out; in the elimination type, the design eliminating epaulet stood out ; in the conversion type, conversion to jacket among many items stood out. In the combination type, the combination between different material texture and identical colors among colors stood out ; in the minimization type, the design minimizing sleeves stood out; in the addition type, the addition of sleeves among many details stood out ; in the magnification type, the design magnifying panels stood out.

Estimation and Elimination of ECG Artifacts from Single Channel Scalp EEG (단일 채널 두피 뇌전도에서의 심전도 잡음 추정 및 제거)

  • Cho, Sung-Pil;Song, Mi-Hye;Park, Ho-Dong;Lee, Kyoung-Joung;Park, Young-Cheol
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1910-1911
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    • 2007
  • A new method for estimating and eliminating electrocardiogram (ECG) artifacts from single channel scalp electroencephalogram (EEG) is proposed. The proposed method consists of emphasis of QRS complex from EEG using least squares acceleration (LSA) filter, generation of synchronized pulse with R-peak and ECG artifacts estimation and elimination using adaptive filter. The performance of the proposed method was evaluated using simulated and real EEG recordings, we found that the ECG artifacts were successfully estimated and eliminated in comparison with the conventional multi-channel techniques, which are independent component analysis (ICA) and ensemble average (EA) method. In conclusion, we can conclude that the proposed method is useful for the detecting and eliminating the ECG artifacts from single channel EEG and simple to use for ambulatory/portable EEG monitoring system.

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Power line interference noise elimination method based on independent component analysis in wavelet domain for magnetotelluric signal

  • Cao, Xiaoling;Yan, Liangjun
    • Geosystem Engineering
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    • v.21 no.5
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    • pp.251-261
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    • 2018
  • With the urbanization in recent years, the power line interference noise in electromagnetic signal is increasing day by day, and has gradually become an unavoidable component of noises in magnetotelluric signal detection. Therefore, a kind of power line interference noise elimination method based on independent component analysis in wavelet domain for magnetotelluric signal is put forward in this paper. The method first uses wavelet decomposition to change single-channel signal into multi-channel signal, and then takes advantage of blind source separation principle of independent component analysis to eliminate power line interference noise. There is no need to choose the layer number of wavelet decomposition and the wavelet base of wavelet decomposition according to the observed signal. On the treatment effect, it is better than the previous power line interference removal method based on independent component analysis. Through the de-noising processing to actual magnetotelluric measuring data, it is shown that this method makes both the apparent resistivity curve near 50 Hz and the phase curve near 50 Hz become smoother and steadier than before processing, i.e., it effectively eliminates the power line interference noise.

An Analysis of Fifth Graders' Solution Methods in Finding the Area of Plane Figure (초등학교 5학년 평면도형의 넓이 구하기 수업에서 나타난 학생들의 해결 방법 분석)

  • Yu, Yeon-Ja;Pang, Jeong-Suk
    • School Mathematics
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    • v.10 no.3
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    • pp.443-461
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    • 2008
  • The purpose of this study was to provide teachers with suggestions on how to teach the unit of finding the area of plane figure by analyzing students' different solution methods. The solution methods were analyzed according to how the original area of the given figure was kept: partition, transformation, and elimination. The partition method was most used. With regard to transformation, students seemed to find it easy to use the area of rectangle. With regard to elimination, students were successful using elimination to find the area of a given figure but had difficulty in producing a formula from the method. The teacher played a key role to encourage students to employ different solution methods, and gave them opportunities to compare and contrast various methods. A cautionary note is that, with too much emphasis on 'variety', the mathematical efficiency may be lost in the process. It suggests that a teacher should be careful to establish appropriate sociomathe- matical norms with students in order that they can make their own judgment on which solution method is mathematically worth and efficient.

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A Study on Torque and Speed Control of Three Phase Induction Motor (3상(相) 유도전동기(誘導電動機)의 토크 및 속도제어(速度制御)에 관한 연구(硏究))

  • Choi, K.H.;Jeong, S.K.;Yang, J.H.
    • Journal of Fisheries and Marine Sciences Education
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    • v.7 no.1
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    • pp.111-126
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    • 1995
  • In general, the electromagnetic transient phenomenon always exists in induction motor(IM) with the torque change. The control performance of IM is very worse than that of D.C motor owing to this transient phenomenon. So many studies about the elimination methods of the transient phenomenon have been making progress. Interesting methods of them are the Field acceleration method(FAM) and the method of impulse addition on the input voltage at the time point of torque change. In this paper, first, the circuit equation of IM is derived from the phase segregation method. The torque equation consisted of the stator and rotor currents is derived from the solving of the circuit equation. As we well known, the transient terms exist in this the torque equation. The method of impulse addition on the input voltage at the instance of torque change is confirmed theoretically for the elimination of the transient phenomenon. With the base on it, the author proposed a real time algorithm to eliminate the transient terms. The control system is consisted of the PI controller with the feedforward of torque change. The author could confirm that the quick stepwise responses of torque and speed can be obtained from response simulations.

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Detection and Location of Cable Fault Using Improved SSTDR (개선된 SSTDR을 이용한 케이블 고장 검출과 위치 계산)

  • Jeon, Jeong-Chay;Kim, Jae-Jin;Choi, Myeong-Il
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.9
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    • pp.1583-1589
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    • 2016
  • This paper proposes an improved spread spectrum time domain reflectometry (ISSTDR) using time-frequency correlation and reference signal elimination method in order to have more accurate fault determination and location detection than conventional (SSTDR) despite increased signal attenuation due to the long distance to cable fault location. The proposed method has a two-step process: the first step is to detect a peak location of the reference signal using time-frequency correlation analysis, and the second step is to detect a peak location of the correlation coefficient of the reflected signal by removing the reference signal. The proposed method was validated through comparison with existing SSTDR methods in open-and short-circuit fault detection experiments of low voltage power cables. The experimental results showed that the proposed method can detect correlation coefficients at fault locations accurately despite reflected signal attenuation so that cable faults can be detected more accurately and clearly in comparison to existing methods.

Prediction on the Ratio of Added Value in Industry Using Forecasting Combination based on Machine Learning Method (머신러닝 기법 기반의 예측조합 방법을 활용한 산업 부가가치율 예측 연구)

  • Kim, Jeong-Woo
    • The Journal of the Korea Contents Association
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    • v.20 no.12
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    • pp.49-57
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    • 2020
  • This study predicts the ratio of added value, which represents the competitiveness of export industries in South Korea, using various machine learning techniques. To enhance the accuracy and stability of prediction, forecast combination technique was applied to predicted values of machine learning techniques. In particular, this study improved the efficiency of the prediction process by selecting key variables out of many variables using recursive feature elimination method and applying them to machine learning techniques. As a result, it was found that the predicted value by the forecast combination method was closer to the actual value than the predicted values of the machine learning techniques. In addition, the forecast combination method showed stable prediction results unlike volatile predicted values by machine learning techniques.

Automatic Lower Extremity Vessel Extraction based on Bone Elimination Technique in CT Angiography Images (CT 혈관 조영 영상에서 뼈 소거법 기반의 하지 혈관 자동 추출)

  • Kim, Soo-Kyung;Hong, Helen
    • Journal of KIISE:Software and Applications
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    • v.36 no.12
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    • pp.967-976
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    • 2009
  • In this paper, we propose an automatic lower extremity vessel extraction based on rigid registration and bone elimination techniques in CT and CT angiography images. First, automatic partitioning of the lower extremity based on the anatomy is proposed to consider the local movement of the bone. Second, rigid registration based on distance map is performed to estimate the movement of the bone between CT and CT angiography images. Third, bone elimination and vessel masking techniques are proposed to remove bones in CT angiography image and to prevent the vessel near to bone from eroding. Fourth, post-processing based on vessel tracking is proposed to reduce the effect of misalignment and noises like a cartilage. For the evaluation of our method, we performed the visual inspection, accuracy measures and processing time. For visual inspection, the results of applying general subtraction, registered subtraction and proposed method are compared using volume rendering and maximum intensity projection. For accuracy evaluation, intensity distributions of CT angiography image, subtraction based method and proposed method are analyzed. Experimental result shows that bones are accurately eliminated and vessels are robustly extracted without the loss of other structure. The total processing time of thirteen patient datasets was 40 seconds on average.

Elimination of Low Order Harmonics in Multilevel Inverters Using Genetic Algorithm

  • Salehi, Reza;Farokhnia, Naeem;Abedi, Mehrdad;Fathi, Seyed Hamid
    • Journal of Power Electronics
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    • v.11 no.2
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    • pp.132-139
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    • 2011
  • The selective harmonic elimination pulse width modulation (SHEPWM) switching strategy has been applied to multilevel inverters to remove low harmonics. Naturally, the related equations do not have feasible solutions for some operating points associated with the modulation index (M). However, with these infeasible points, minimizing instead of eliminating harmonics is performed. Thus, harmful harmonics such as the $5^{th}$ harmonic still remains in the output waveform. Therefore, it is proposed in this paper to ignore solving the equation associated with the highest order harmonics. A reduction in the eliminated harmonics results in an increase in the degrees of freedom. As a result, the lower order harmonics are eliminated in more operating points. A 9-level inverter is chosen as a case study. The genetic algorithm (GA) for optimization purposes is used. Simulation results verify the proposed method.

Cascaded Multi-Level Inverter Based IPT Systems for High Power Applications

  • Li, Yong;Mai, Ruikun;Yang, Mingkai;He, Zhengyou
    • Journal of Power Electronics
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    • v.15 no.6
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    • pp.1508-1516
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    • 2015
  • A single phase H-bridge inverter is employed in conventional Inductive Power Transfer (IPT) systems as the primary side power supply. These systems may not be suitable for some high power applications, due to the constraints of the power electronic devices and the cost. A high-frequency cascaded multi-level inverter employed in IPT systems, which is suitable for high power applications, is presented in this paper. The Phase Shift Pulse Width Modulation (PS-PWM) method is proposed to realize power regulation and selective harmonic elimination. Explicit solutions against phase shift angle and pulse width are given according to the constraints of the selective harmonic elimination equation and the required voltage to avoid solving non-linear transcendental equations. The validity of the proposed control approach is verified by the experimental results obtained with a 2kW prototype system. This approach is expected to be useful for high power IPT applications, and the output power of each H-bridge unit is identical by the proposed approach.