• Title/Summary/Keyword: Analytical method

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A new analysis on timing jitters in APD receivers of optical communication systems when considering intersymbol interferences (APD를 사용하는 광통신 시스템 수신기에서 심벌간 간섭을 고려할 경우 타이밍 지터에 대한 새로운 해석)

  • 신요안;은수정;김부균
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.3
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    • pp.539-546
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    • 1997
  • In this paper, we proposed a new mehtod to analyze the performance degradation by timing jitters in the APD (avalanche photodiode) receivers of intensity modulation/direct detection digital optical communication systems where raised cosine pulse-shaping filters are used to reduce the effect of noise while minimizing intersymbol interferences. The proposed analytical method is an extension of an analytical method we have already developed for pin diode receivers, and incorporates the effects of APD's multiplication factor and resulting shot noise. Using the proposed analytical method, we derive an approximated power penalty due to timing jitters based on an assumption of Gaussian distribution for timing jitters, and compare with that of the conventional analytical method. The results obtained from the proposed analytical method show that conventional analytical methods underestimate the influence of timing jitters on the reciver performance. The results also show that APD's multiplication factor which optimizes receiver sensitivity is smaller than that obtained by the conventional analytical method.

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Analysis and Optimization of the Axial Flux Permanent Magnet Synchronous Generator using an Analytical Method

  • Ikram, Junaid;Khan, Nasrullah;Junaid, Qudsia;Khaliq, Salman;Kwon, Byung-il
    • Journal of Magnetics
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    • v.22 no.2
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    • pp.257-265
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    • 2017
  • This paper presents a 2-D analytical method to calculate the back EMF of the axial flux permanent magnet synchronous generator (AFPMSG) with coreless stator and dual rotor having magnets mounted on both sides of rotor yoke. Furthermore, in order to reduce the no load voltage total harmonics distortion (VTHD), the initial model of the coreless AFPMSG is optimized by using a developed analytical method. Optimization using the 2-D analytical method reduces the optimization time to less than a minute. The back EMF obtained by using the 2-D analytical method is verified by a time stepped 3-D finite element analysis (FEA) for both the initial and optimized model. Finally, the VTHD, output torque and torque ripples of both the initial and optimized models are compared with 3D-FEA. The result shows that the optimized model reduces the VTHD and torque ripples as compared to the initial model. Furthermore, the result also shows that output torque increases as the result of the optimization.

Development of new integrated particle tracking techniques combining the numerical method, semi-analytical method, and analytical method (수치, 해석적, 준 해석적 및 해석적 방법을 통합한 새로운 입자추적기술 개발)

  • Suk, Hee-Jun
    • Journal of Soil and Groundwater Environment
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    • v.13 no.6
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    • pp.50-61
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    • 2008
  • In this study, new integrated particle tracking algorithm was developed to reduce the inherent problem of Eulerian- Lagrangian method, or adverse effect of particle tracking error on mass balance error. The new integrated particle tracking algorithm includes numerical method, semi-analytical method, and analytical method which consider both temporal and spatial changes of velocity field during time step. Detail of mathematical derivations is well illustrated and four examples are made to verify through the comparison of the new integrated particle tracking with analytical solution or Runge-Kutta method. Additionally, It was shown that the there is better superiority of the new integrated particle tracking algorithm over other existing particle tracking method such as Lu's method.

Theoretical analysis of Y-shape bridge and application

  • Lu, Peng-Zhen;Zhang, Jun-Ping;Zhao, Ren-Da;Huang, Hai-Yun
    • Structural Engineering and Mechanics
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    • v.31 no.2
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    • pp.137-152
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    • 2009
  • Mechanic behavior of Y-shape thin-walled box girder bridge structure is complex, so one can not exactly hold the mechanical behavior of the Y-shape thin-walled box girder bridge structure through general calculation theory and analytical method. To hold the mechanical behavior better, based on elementary beam theory, by increasing the degree of freedom analytical method, taking account of restrained torsiondistortion angledistortion warp and shearing lag effect at the same time, authors obtain a thin-walled box beam analytical element of 10 degrees of freedom of every node, derive stiffness matrix of the element, and code a finite element procedure. In addition, authors combine the obtained procedure with spatial grillage analytical method, meanwhile, they build a new analytical method that is the spatial thin-walled box girder element grillage analysis method. In order to validate the precision of the obtained analysis method, authors analyze a type Y-shape thin-walled box girder bridge structure according to the elementary beam theory analytical method, the shell theory analytical method and the spatial thin-walled box girder element grillage analysis method respectively. At last, authors test a type Y-shape thin-walled box girder bridge structure. Comparisons of the results of theory analysis with the experimental text show that the spatial thin-walled box girder element grillage analysis method is simple and exact. The research results are helpful for the knowledge of the mechanics property of these Y-shape thin-walled box girder bridge structures.

Nonlinear Analysis for the Prediction of Lateral Behavior of Single Piles in Non-homogeneous Sandy Soil (비균질 사질토 지반에서 단일말뚝의 수평거동 예측을 위한 비선형 해석기법)

  • 김영수;김병탁;허노영
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.5-16
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    • 2000
  • THe purpose of this paper is to suggest the analytical method which can predict lateral nonlinear behavior in non-homogeneous soil using the coefficient of soil resistance and ultimate soil resistance. Those parameters are obtained through back analysis on the base of the results of a series of model tests.Analytical method of Chang is more or less difficult to predict nonlinear behavior in non-homogeneous sol. So, in this study, for the prediction of nonlinear behavior the compositive analytical method which apply the p - y curve to Chang model is suggested. Also, the program is developed to predict nonlinear behavior using the compositive analytical method and it can be used to calculated the deflection, bending moment and soil reaction with DFM in non-homogeneous soil. To establish applicability of the suggested analytical method, the results of model tests and field tests and Pentagon2D finite element program are compared with those of the compositive analytical method. In the analysis values of the coefficient of soil reaction and ultimate soil resistance are also applied to the case of non-homogeneous soil. Lateral defection calculated using the compositive analytical method has been found to be in good agreement with values measured in field and model load tests.

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Eddy Current Analysis of Linear Switched Reluctance Motor using Analytical Method (해석적 방법을 이용한 직선형 스위치드 릴럭턴스 전동기의 2차측 와전류 해석)

  • Jang, Seok-Myeon;Park, Ji-Hoon;Han, Cheol;You, Dae-Joon;Seo, Jin-Ho;Lee, Kyoung-Bok
    • Proceedings of the KIEE Conference
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    • pp.1077-1078
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    • 2011
  • This paper deals with eddy current analysis of linear switched reluctance motor using analytical method. First, flux density is calculated using analytical method. From flux density, eddy current is analyzed according to moving speed. Finally, analyzed result is compared with finite element method.

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The calculation of inductance profile for linear switched reluctance motor by analytical method (해석적 방법에 의한 리니어 스위치드 릴럭턴스 전동기의 인덕턴스 프로파일 산정)

  • Jang, Seok-Myeong;Park, Ji-Hoon;Choi, Jang-Young;Sung, Ho-Kyung
    • Proceedings of the KIEE Conference
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    • pp.138-140
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    • 2005
  • This paper deals with inductance profile of linear switched reluctance motor. Inductance profile of LSRM calculate at align and unalign position using analytical method. Analytical method of this paper used space harmonics method, Also, analysis result compares with data that is derived through an experiment, and proved validity.

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A Study on PCB Analysis of Insulating Oil in Waste Condenser (폐콘덴서의 절록유 중에 함유된 PCB 분석에 관한 연구)

  • 김귀자;박재주
    • Environmental Analysis Health and Toxicology
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    • v.4 no.1_2
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    • pp.11-17
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    • 1989
  • A quantitative analytical method of highly concentrated PCB is established in the research. With the quantitative analytical method PCB of insulating oil was examined. The following conclusions are derived from this research. 1. The recovery ratio was 95.7% with the quantitative analytical method, which indicates it can be used for the analysis of PCB. 2. PCB concentration of insulation oil in waste condenser was found to be 21.2% thru 13.85% , which was highly concentrated. 3. PCB insulation oil in waste condenser was same as PCB-42.

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Determination of Total Volatile Bases of Tobacco Using Near Infrared Spectroscopy (근외적 분광분석법을 이용한 담배 중 전휘발성염기 분석)

  • Kim Yong-Ok;Jang Gi-Chul;Lee Chul-Hee;Chung Han-Joo
    • Journal of the Korean Society of Tobacco Science
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    • v.27 no.2
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    • pp.207-211
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    • 2005
  • This study was carried out to develop calibration equation of total volatile bases of tobacco leaf using near infrared spectroscopy(NIRS). Burley, imported flue-cured and oriental leaf tobacco samples were collected in 2005 crop year. Calibration equation was developed by modified partial least square method. The standard error of calibration and $R^2$ between traditional analytical method and NIRS analytical method were $0.038\%$, 0.983 for burley and $0.027\%$, 0.986 for imported flue-cured and oriental leaf, respectively. The standard error of performance and $R^2$ between traditional analytical method and NIRS analytical method were $0.048\%$, 0.940 for burley and $0.024\%$, 0.986 for imported flue-cured and oriental leaf, respectively. From these results, the NIRS analytical method seems to be applicable in analyzing total volatile bases of tobacco.

Introduction of the Rapid Analysis Method for PCBs in Insulating Oils and Its Comparison Study to the Analysis Method in Korea

  • Hong, Jang-Ho;Takahashi, Tomohumi;Ishizaka, Takahiro;Toita, Hideki;Min, Byung-Yoon;Honda, Katsuhisa
    • Environmental Engineering Research
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    • v.16 no.1
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    • pp.11-18
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    • 2011
  • The aim of this research was to introduce a new rapid analysis method (heating of the multi-layer silica gel column/alumina column) for polychlorinated biphenyls in insulating oils, and to compare our new method with the analytical method currently used in Korea. The entire pretreatment procedure was completed within 2 hr, using about only 20 mL of solvents via our rapid analytical method. Furthermore, the pretreatment procedure can always be uniformly performed, regardless of oil type (JIS 1~JIS 7 and KS 1~KS 7). The recovery rates were more than 89%, with relative standard deviations below 6.0%. In conclusion, this rapid analytical method could reduce the pretreatment time and solvent usage by 1/10 and between 1/25 and 1/50, respectively, compared to analytical method currently used in Korea.