• Title/Summary/Keyword: Deviation ratio

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Multi - channel Spectrum Analyzer for High Capacity Optical Transport Networks

  • Youn, Ji-Wook;Kim, Hyung-Joo;Lee, Jong-Hyun
    • Journal of the Optical Society of Korea
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    • v.7 no.4
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    • pp.249-252
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    • 2003
  • A simple multi-channel spectrum analyzer using an InGaAs array sensor and a diffraction grating is proposed and developed for high-capacity optical transport networks. With the developed multichannel spectrum analyzer, we could measure signal power, wavelength, and optical signal-to-noise ratio of each channel for multi-channel optical signals with 100 GHz and 50 GHz channel spacing, simultaneously. We could measure each channel power and wavelength with a deviation of less than 0.2 dB and 0.063 nm, respectively. We have obtained optical signal-to-noise ratio with a deviation of less than 1.0 dB compared with conventional optical spectrum analyzer in the wide input power range between -42 dBm and -27 dBm per channel.

A Survey on Pants Grading of the Korean Apparel Industry (국내 의류 업체의 바지 그레이딩 실태 조사)

  • Lee, Mi-Sook
    • Fashion & Textile Research Journal
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    • v.11 no.6
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    • pp.896-903
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    • 2009
  • The purpose of this study was to compare and analyze the present condition of pants grading and the methods for the specific dimensional increments, a questionnaire has been conducted. For the questionnaire, 16 casual wear brands, which were on higher ranking of sales in Korea, were selected. The results are summarized as follows. Based on the pants grading data resulting from the research conducted on the (16) domestic clothing brands, the grading method could be classified into three different types. According to the criteria; i.e., the front and back divided by crease of pants and the deviation ratio of the grading increments of the waist and the hip girth, the grading types were (1) G1: front 5:5, back 5:5, (2) G2: front 4:6, back 4:6, and (3) G3: front 4:6, back 3:7.

Estimation of Probability Valuable for Diffusion Coefficient of Chloride Ion (염소이온 확산계수의 확률변수 평가)

  • Bae Su Ho;Lee Kwang Myong;Kim Jee Sang;Jung Sang Hwa
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.515-518
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    • 2005
  • In recent years, many research works have been carried out in order to obtain a more controlled durability and long-term performance of concrete structures exposed to chloride environments. In particular, the development of new procedures for probability-based durability analysis and design has been proved to be very valuable. To carry out the procedures described above, the statistical properties of design valuables such as diffusion coefficient of chloride ion, surface chloride concentration, and chloride threshold value etc. should be known. For this purpose, this paper presents the statistical properties of the diffusion coefficient of chloride ion such as mean value and standard deviation with water-cement(w/c) ratio and curing conditions, respectively. It was observed from the test that the standard deviation for the diffusion coefficient of chloride ion was found to be small with decrease in the w/c ratio irrespective of curing conditions and that of standard curing was found to be smaller than that of field curing.

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A Study on the Precision Cutting Characteristics by the Diamond Tool on the Cutting Distance (다이아몬드 공구의 절삭거리에 따른 정밀가공 특성 연구)

  • Yu, Ki-Hyun;Cheong, Chin-Yong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.5
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    • pp.127-133
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    • 1998
  • This research intends to gain the sight for the qualitative characteristics of precision cutting by using the CNC lathe with a mono-crystal diamond(MCD) and a poly-crystal diamond(PCD) tool on the cutting distance. In case of an MCD tool, as the cutting distance increases, the surface roughness becomes worse and the standard deviation of surface roughness is small. In case of a PCD tool, as the cutting distance increases, the surface roughness becomes stable with a large standard deviation. The cutting force ratio(Ft/Fn) decreases as the nose radius increases and the decreasing ratio becomes larger for small nose radius.

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Signal-to-Noise Ratio Formulas of a Scalar Gaussian Quantizer Mismatched to a Laplacian Source

  • Rhee, Ja-Gan;Na, Sang-Sin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.6C
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    • pp.384-390
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    • 2011
  • The paper derives formulas for the mean-squared error distortion and resulting signal-to-noise (SNR) ratio of a fixed-rate scalar quantizer designed optimally in the minimum mean-squared error sense for a Gaussian density with the standard deviation ${\sigma}_q$ when it is mismatched to a Laplacian density with the standard deviation ${\sigma}_q$. The SNR formulas, based on the key parameter and Bennett's integral, are found accurate for a wide range of $p\({\equiv}\frac{\sigma_p}{\sigma_q}\){\geqq}0.25$. Also an upper bound to the SNR is derived, which becomes tighter with increasing rate R and indicates that the SNR behaves asymptotically as $\frac{20\sqrt{3{\ln}2}}{{\rho}{\ln}10}\;{\sqrt{R}}$ dB.

A Study on the Improvement of the JADE Algorithm (JADE알고리즘의 개선에 관한 연구)

  • Yoon H.R.;Lee J.S.;Jeon D.K.;Lee K.J.
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.5
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    • pp.305-310
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    • 2003
  • In this paper, we proposed an IJADE(Improved joint approximate diagonalisation of eigenmatrices) which use high order statistics instead of second order statistics for data whitening. For simulation, we artificially construct signals mixed with two ECG signals, 60Hz power line interference and 16Hz sine signal and then put them into a JADE and an IJADE. To evaluate the performance of separated ECG signal in each algorithm, we have adopted indices such as kurtosis, standard deviation ratio, correlation coefficient and euclidean distance. As a results, IJ ADE showed theimproved performances as kurtosis of $2\%,$ standard deviation ratio of 0.2194, and Euclidean distance of 0.07 except correlation coefficient showing similar value. In conclusion, the proposed IJADE showed a good performance in separating ECG and a possibilities in applying to the various biological signal.

An Analysis of the Optimal Thermal Storage Time of Air-Conditioning System with Slab Thermal Storage : An Analysis by the Gradient Method Algorithm (슬래브축열의 최적축열시간 산정 : 구배법 알고리즘에 의한 해석)

  • Jung, Jae-Hoon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.10
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    • pp.702-709
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    • 2008
  • In this paper, the optimal thermal storage time of an air-conditioning system with slab thermal storage in office building was analyzed on the basis of the gradient method algorithm. The sum of room temperature deviation and heat extraction rate was set to the criterion function. It was calculated that four hours is the optimal thermal storage time under the standard evaluation criterion. Furthermore, some case studies were executed by controlling ratio of weight functions of room temperature deviation and heat extraction rate in criterion function. It is possible to design many kinds of optimal operation of an air-conditioning system with slab thermal storage by controlling ratio of the weight functions in criterion function.

Method of Decreasing the Deviation of Corrected Engine Torque using Knock Correction Rate in Gasoline Engine Performance Test on Dynamometer (가솔린엔진 대상 성능시험시의 노킹보정률을 사용한 엔진 수정토크의 편차개선)

  • Cho, Yoon-Ho;Kim, Woo-Tai;Bae, Choong-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.4
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    • pp.1-7
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    • 2008
  • Recent trends of development in small size gasoline engines are both to have higher compression ratio for the purpose of improved fuel consumption and to advance spark timing up to DBL in a low to mid engine speed region for a good acceleration performance of vehicles. However, there occurs the deviation of corrected engine torque results during engine performance test on dynamometer because test conditions influence the onset of knock. Therefore, this research shows the test deviation of corrected engine torque decreases when knock correction rate is used.

Fault Location Diagnosis Technique of Photovoltaic Power Systems through Statistic Signal Process of its Output Power Deviation (출력편차의 통계학적 신호처리를 통한 태양광 발전 시스템의 고장 위치 진단 기술)

  • Cho, Hyun Cheol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.11
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    • pp.1545-1550
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    • 2014
  • Fault detection and diagnosis (FDD) of photovoltaic (PV) power systems is one of significant techniques for reducing economic loss due to abnormality occurred in PV modules. This paper presents a new FDD method against PV power systems by using statistical comparison. This comparative approach includes deviation signals between the outputs of two neighboring PV modules. We first define a binary hypothesis testing under such deviation and make use of a generalized likelihood ratio testing (GLRT) theory to derive its FDD algorithm. Additionally, a recursive computational mechanism for our proposed FDD algorithm is presented for improving a computational effectiveness in practice. We carry out a real-time experiment to test reliability of the proposed FDD algorithm by utilizing a lab based PV test-bed system.

Variation of Tracer Distribution During the Antarctic Polar Vortex Breakup Shown in ILAS and ILAS-II Data (ILAS와 ILAS-II 자료에서 나타난 남극 와동 붕괴기간의 미량기체 분포변화)

  • Choi, Wookap;Lim, Kyungsoo
    • Atmosphere
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    • v.20 no.3
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    • pp.367-377
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    • 2010
  • Variation of tracer distribution during the vortex-breakup period in the Antarctic region was observed by the data from the Improved Limb Atmospheric Spectrometer (ILAS) and ILAS-II. All four trace species including methane, nitrous oxide, ozone, and water vapor show similar patterns of vertical gradient in spite of different structures of zonal mean mixing ratio. Timings of vortex breakup on each level are estimated by two different methods, and they are compared with zonal standard deviations following the latitude circle of each trace species. Although the tracers have different chemical life times and sink/source, the zonal standard deviation patterns show remarkable similarities. The zonal standard deviation shown here to measure the zonal asymmetry of tracer distribution is believed to diagnose the timing of the Antarctic polar-vortex breakup reasonably well.