• Title/Summary/Keyword: method comparison

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A Comparison between 3-D Analytical and Finite Difference Method for a Trapezoidal Profile Fin

  • Lee, Sung-Joo;Kang, Hyung-Suk
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.41-50
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    • 2001
  • A comparison is made of the temperature distribution and heat loss from a trapezoidal profile fin using two different 3-dimensional methods. These two methods are analytical and finite difference methods. In the finite difference method 78 nodes are used for a fourth of the fin. A trapezoidal profile fin being the height of the fin tip is half of that of the fin base is chosen arbitrarily as the model. One of the results shows that the relative error in the total convection heat loss obtained by using 78 nodes in the finite difference method as compared to the heat conduction through the fin root obtained by analytic method seems to be good (i.e., -3.5%

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Analysis of Fingerprint Recognition Characteristics Based on New CGH Direct Comparison Method and Nonlinear Joint Transform Correlator

  • Jeong, Man-Ho
    • Journal of the Optical Society of Korea
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    • v.13 no.4
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    • pp.445-450
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    • 2009
  • Fingerprint recognition using a joint transform correlator (JTC) is the most well-known technology among optical fingerprint recognition methods. The JTC method optically compares the reference fingerprint image with the sample fingerprint image then examines match or non-match by acquiring a correlation peak. In contrast to the JTC method, this paper presents a new method to examine fingerprint recognition by producing a computer generated hologram (CGH) of those two fingerprint images and directly comparing them. As a result, we present some parameters to show that fingerprint recognition capability of the CGH direct comparison method is superior to that of the JTC method.

Reconstruction of Qihaishu, an ancient diagnostic method in Huangdineijing (고대 진단법 '기해술(奇咳術)'의 복원)

  • Kim, Ki-Wang
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.13 no.2
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    • pp.1-13
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    • 2009
  • Objectives: Huangdineijing, the major classic of Oriental Medicine, preserves several precedent diagnostic classics and it's methods. Qihaishu (奇咳術), is a name of such classic, and the name of it's essential method at the same time. Up to now, the whole features of that method has not been unveiled. In the present thesis, I presented some clues to figure out the method - Qihaishu. Methods: By comparison of some articles in Canggongliechuan (in Shiji) (史記倉公列傳) to those of Huangdineijing Suwen (黃帝內經素問), I reconstructed the diagnostic steps of Qihaishu. Results: It was proved that Qihaishu method was carried by comparison of left and right arterial pulse under the Wuxing (五行) context. Conclusion: Qihaishu is not a set of knowledge describing the features of diseases, but a pulse palpation method to get prognosises.

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Comparison of Korteweg-Helmholtz Electromagnetic Force Density and Magnetic Charge Force Density in Magnetic Systems (자기시스템의 Korteweg-Helmholtz 전자력 밀도와 자하 전자력 밀도의 비교)

  • Lee, Se-Hui;Choe, Myeong-Jun;Park, Il-Han
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.4
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    • pp.226-232
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    • 2000
  • In magnetic systems, distribution of electromagnetic force density causes mechanical deformation, which results in noise and vibration. In this paper, Korteweg-Helmholtzs energy method and equivalent magnetic charge method are employed for comparison of their resulting distributions of force density. The force density from the Korteweg-Helmholtzs method is expresses with two Maxwell stresses on the inside and the outside fo magnetic material respectively. The other is calculated using the magnetic Coulombs law. In the numerical model of an electromagnet, their numerical results are compared. The distributions by the two methods are almost the same. And their total forces are also shown to be the same to the one calculated from the conventional Maxwell stress tensor. But the magnetic charge method is easier and more efficient in numerical calculation.

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PWM Method to Reduce Input Current THD for Three-phase Rectifier (3상 정류기의 입력전류 THD저감을 위한 PWM 방법)

  • Shin, Hee-Kuen;Yoon, Byung-Chul;Kim, Hag-Wone;Cho, Kwan-Yuhl;Lim, Byung-Kuk;Ko, Don-Yeol
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.17-19
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    • 2010
  • In this paper, new PWM method is proposed to reduce input current THD of PWM Rectifier. In general, the carrier comparison PWM method is used for PWM rectifier in which triangle wave is used as a carrier wave. However, large d-axis current ripple by this method can be a source of large THD. In this paper, new carrier comparison PWM method is proposed in which sawtooth wave is used as a carrier wave. Depending on the phase of the voltage commands, the rising or falling sawtooth wave is selected to reduce the THD. The simulation results verified the performance of the proposed method.

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A Study on Daylight Control Method for Securing Visual Comfort and Reducing Lighting Loads on Interior Lighting Environment (실내조명환경의 시각적 쾌적성 확보 및 조명부하 저감을 위한 채광제어방법에 관한 연구)

  • Han, Sang-Pil
    • Journal of the Korean Solar Energy Society
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    • v.32 no.6
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    • pp.100-105
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    • 2012
  • In previous study, to investigate the impression of the compound lighting based on the AC-Model at the full-size room, the impressions of various compound lighting were completed as compared with that of the uniform lightings through the comparison method (a paired comparison) by Semantic Differential scaling. Also, we examined the effect of the supplementary lighting type increasing the lights at the side of the window and the blind-control lighting type, and they were compared with the existing compound lighting type. In results, pared comparison of the compound lighting and the uniform lighting, indicates that the impression of the compound lighting is generally similar to that of the uniform lighting when there are same ratios of the light from the window. Based on these results, we suggest that the AC-Model might be applied to various conditions. And we also introduce the method for daylighting that it is possible to reduce discomfort glare and to improve visual impressions as the supplementary type and blind-control type on the compound lighting. And it was found that electric power consumption of the compound lighting room was lower than that of the uniform lighting room when as same lighting ratio of the compound lighting and the uniform lighting from the window was provided or there was the lighting distribution simulated to same light ratio from the window. Since the method of the ACModel was described in the experimental condition, additional studies should be performed to determine if this model could be applied to different window configurations, lighting layout and types of a room.

A Study on Audience Counting Method in Auditorium Based on Pattern Comparison (패턴비교를 이용한 공연장에서의 관객 수 카운팅 방법에 관한 연구)

  • Sim, Sang-Kyun;Park, Young-Kyung;Kim, Joong-Kyu
    • The KIPS Transactions:PartB
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    • v.14B no.1 s.111
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    • pp.13-22
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    • 2007
  • In this paper, we propose an audience counting method in an auditorium based on pattern comparison. The previous counting methods based on object detection can't exactly count the audience in real time because auditorium has coarse illumination condition and so many audiences. Therefore, in this paper, we count the audience in an auditorium with fixed seats by the method which the pattern from each reference seat is compared to the pattern from each input seat. Especially, to overcome limitations based on either illumination or noise, two pattern comparison methods are efficiently employed and combined. One is based on the amplitude projection, and the other is based on Walsh-Hadamard Kernel. Walsh-Hadamard Kernel has the characteristic which complements amplitude projection. Therefore, we ran achieve the accurate counting in the presence of coarse illumination and noise. The experimental results show that our method performs well on sequences of images acquired in an auditorium. We also verify a realistic possibility for other applications applying our method to the parking positioning system.

A Method to Compare Images for Managing Tools to Repair Ships (선박 수리장비 관리를 위한 이미지 비교기법)

  • Park, Sung-Hoon;Kim, Jin-Deog
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.10
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    • pp.2489-2496
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    • 2014
  • The existing ship repair tool management system based on hand writing has many problems such as frequent loss of tool and overdue. To solve this problem, same systems have adopted the bar-code system. However, the systems can't cope with a problem to substitute spurious tool for genuine one on bar-code damage. Therefore, additional validation steps are necessary in order to manage expensive ship repair tool. In this paper, we propose an image comparison method for ship repair tool management. To be more concrete, we propose a normalization method and determination conditions for image comparison to use characteristics of mobile device. The normalization method makes use of the characteristics of mobile device that provides functions of real time recording, overlapping and cropping images. The proposed method applies three conditions(sum of inner angles, size of angle, position of corner coordinates) into the comparison module. The implemented system shows good performance on change direction, lighting, size and etc. The accuracy is more than 95%.

PMP Estimation and Its Application for the Design Flood Determination in River Basin (하천유역의 설계 홍수량 결정을 위한 P.M.P의 산정 및 적용)

  • 이순택;박정규
    • Proceedings of the Korea Water Resources Association Conference
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    • 1986.07a
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    • pp.93-101
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    • 1986
  • This study aims at analysis and application of PMP(Probable Maximum Precipitation) for the determination of design of major hydraulic structures. PMP was estimated by hydro-meteorolgical method and envelope curve method. PMF(Probable Maximum Flood) was then estimated from this PMP by synthetic unit hydrograph method and chow method. From the comparison of three methods for PMP estimation of magnitude of PMP in order of statistical, hydro-meteorlogical, envelope curve method. Amon PMP results estimated by each method it is believed that the hydro-meteorological method gave the best proper value in comparison with historical maximum rainfall because of this method reflected upon all meteorological factor. From the comparison of PMP with probable rainfall and flood, it was shown that estimated value by statistical method and hydro-metelogical method were nearly equivalent to the value of return period 200 to 500 year. It was found that PMF estimated from would be more safe for the design of major hydraulic structures in the consinderation.

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A Comparison Study of Multiclass SVM Methods in Microarray Data

  • Hwang, Jin-Soo;Lee, Ji-Young;Kim, Jee-Yun
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.2
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    • pp.311-324
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    • 2006
  • The Support Vector Machine(SVM) is very functional and efficient classification method to any other classification analysis method. However, its optimal extension to more than two classes is not obvious. In this paper several multi-category SVM methods are introduced and compared using simulation and real data sets. Also comparison with traditional multi-category classification and SVM based methods is performed.

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