• Title/Summary/Keyword: correlation error

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The Factor of Knee Joint Function in Women (여성의 무릎관절 기능 영향요인)

  • Lee, Hyun-Ok;Yang, Kyung-Hye
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.16 no.2
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    • pp.67-75
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    • 2010
  • Purpose: The purpose of this is to identify the relationship among the age, body mass index(BMI) and exercise frequency(EF) with knee joint position sense in korean healthy women. Methods: Healthy women of 328 who participated in this study were tested knee joint position sense; reposition error was measured with a Myrin goniometer. Each reposition error was analyzed using descriptive statics, pearson correlation coefficients, and stepwise multiple regression. Results: The mean reposition error by age groups was significant decrease getting older. The mean reposition error by BMI groups was significant decrease getting higher. And the mean reposition error by EF groups was significant decrease getting lower. The knee joint position sense showed a significantly correlation with age(r=0.36, p=.00), BMI(r=0.34, p=.00) and EF(r=-0.50, p=.00). The most powerful predictor of knee joint position sense was EF. The reposition error according to stepwise multiple regression is $3.36+(-2.64){\times}EF+0.13{\times}age$, and account for 46%($R^2=0.46$) of the variance in the knee joint position sense. Conclusion: The older the women are, for prevent of knee injuries due to decreased joint position sense, regular exercise is essential factor.

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A Canonical Correlation Analysis of the Relationship between Menu Management Variables and Performance in Contract-Foodservice Operations (위탁 급식 점포의 메뉴 운영 요인과 성과의 연관성에 관한 연구)

  • Park, Ju-Yeon;Kim, Tae-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.6
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    • pp.1089-1098
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    • 2008
  • The principal objective of this study was to reveal the relationship between the menu management indicators and menu performance indicators in contract-foodservice operations. Menu indicators differed according to the type of business, type of contract, type of serving, and number of service lines. In accordance with the results of our correlation analysis, we noted significant correlations between menu performance indicators and menu management indicators. The first of these was the correlation between the food cost ration and meal counts, food loss, and the use of prepared vegetables. The second of these was the correlation between food cost per meal and forecasting error, food loss, and inventory turnover. The last of these correlations was the negative correlation between menu CSI(customer satisfaction index) and the use of prepared vegetables. According to the results of our canonical correlation analysis, 2 significant functions were identified. In the first function, we noted significant correlations between meal counts, use of prepared vegetables, food loss, and food cost ratio. Additionally, we noted significant correlations between forecasting error, inventory turnover, food loss, and food cost per meal in the second function. Menu management indicators had no influence on customer satisfaction.

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Error Performance Analysis of DS-CDMA System in Wireless Channel

  • Kang, Heau-Jo
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.1-5
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    • 2003
  • This paper discusses the spectral efficiency and performance of asynchronous direct sequency spread spectrum multiple access systems strict bandwidth limitation by Nyquist filtering. The signal to noise plus interference ratio(SNIR) at the output from the correlation receiver is derived analytically taking the cross correlation characteristics of spreading sequences into account, and also an approximated SNIR of a simple form is presented for the systems employing Gold sequences. Based on the analyzed result of SNIR, bit error rate performance and spectral efficiency are also estimated. and at last, we analyzed improvement rate using RS, convolution as a method for improving functions.

AN EVALUATION OF THE SOLAR RADIO BURST LOCATOR (SRBL) AT OVRO

  • HwangBo, J.E.;Bong, Su-Chan;Cho, K.S.;Moon Y.J.;Lee, D.Y.;Park, Y.D.;Gary Dale E.;Dougherty Brian L.
    • Journal of The Korean Astronomical Society
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    • v.38 no.4
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    • pp.437-443
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    • 2005
  • The Solar Radio Burst Locator (SRBL) is a spectrometer that can observe solar microwave bursts over a wide band (0.1-18 GHz) as well as detect the burst locations without interferometry or mechanical scanning. Its prototype has been operated at Owens Valley Radio Observatory (OVRO) since 1998. In this study, we have evaluated the capability of the SRBL system in flux and radio burst location measurements. For this, we consider 130 microwave bursts from 2000 to 2002. The SRBL radio fluxes of 53 events were compared with the fluxes from USAF/RSTN and the burst locations of 25 events were compared with the optical flare locations. From this study, we found: (1) there is a relatively good correlation (r = 0.9) between SRBL flux and RSTN flux; (2) the mean location error is about 8.4 arcmin and the location error (4.7 arcmin) of single source events is much smaller than that (14.9 arcmin) of multiple source events; (3) the minimum location error usually occurred just after the starting time of burst, mostly within 10 seconds; (4) there is a possible anti-correlation (r = -0.4) between the pointing error of SRBL antenna and the location error. The anti-correlation becomes more evident (r=-0.9) for 6 strong single source events associated with X-class flares. Our results show that the flux measurement of SRBL is consistent with that of RSTN, and the mean location error of SRBL is estimated to be about 5 arcmin for single source events.

The Correlation of Refractive Error and Ocular Dimensions in Older Age (고령의 연령에서 굴절이상과 안광학 성분들의 연관성 분석)

  • Lim, Byung Kwan;Jeon, Soon-Woo;Jeong, Youn Hong
    • Journal of Korean Ophthalmic Optics Society
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    • v.16 no.3
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    • pp.293-297
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    • 2011
  • Purpose: This study was to know the correlation among refractive error and the dimensions of ocular components on older adults. Methods: The subjects were 95 older age who had no eye diseases. The refractive error, corneal radius, corneal diopter, axial length, anterior chamber depth and lens thickness were measured and analysed. Results: The axial length(AL)/corneal radius(CR) ratio was positively correlated with the corneal diopter, axial length, the anterior chamber depth. Then it was negatively correlated with corneal radius. It was shown that the highest correlation was between the corneal diopter and axial length (r = -0.545, p = 0.000). The spherical equivalent of the refractive error was negatively correlated with the AL/CR ratio. Conclusions: It was shown that the AL/CR ratio was a very important indicator for diagnosing the refractive error of the old age.

Comparison of Accommodative Response among Emmetropes, Spectacle and Contact Lens Wearer (정시, 안경 및 콘택트렌즈 착용자의 조절반응량 비교)

  • Lee, Kyu-Byung;Park, Jeehyun;Kim, Hyojin
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.4
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    • pp.403-410
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    • 2012
  • Purpose: The purposes of this study are to investigate accommodative response among emmetropes, spectacle wearer and contact lens wearer, and correlation between refractive error and accommodative respons for each group. Methods: The 72 subjects(144 eyes) who do not have any ocular diseases were participate in this study. Subjects were categorized into emmetropes, spectacle wearer and contact lens wearer by refractive error using closed-field auto-refractometer. We measured dominant eye, naked/habitual visual acuity and refractive error of monocular/binocular vision of refractive error for far/near distance with open-field auto-refractometer and calculated accommodative lag. Results: There were no significant difference of accommodative lag between right and left eye dominant and non-dominant eye, monocular and binocular vision, and spectacle lens wearer and contact lens wearer, However the accommodative lag of binocular vision was severe than monocular vision at near. The lag of myopia was larger than emmetropes, and male was larger than female. Significant correlation was found between refractive error and accommodative lag in total subjects and the same result was found in emmetropes and contact lens wearer. However there were no significant correlation in the spectacle wearer. Conclusions: There were significant difference between emmetrops and myopes in terms of accommodative lag, however accommodative lag of spectacle wearer was not different with contact lens wearer in myopes. There were also significant correlation between refractive error and accommodative lag in emmetropes and contact lens wearer, but the accommodative lag of spectacle wearer was not significantly correlated with refractive error.

A Study on Determining the Optimal Time to Launch of Software Considering Error Correction Time (오류 수정 시간을 고려한 소프트웨어 최적 출시 시점 결정 연구)

  • Ahn, Cheol-Hoon
    • Journal of Software Assessment and Valuation
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    • v.16 no.2
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    • pp.69-76
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    • 2020
  • In this paper, the problem of determining the optimal time to market of software was studied using error correction time, an indicator of error correction difficulty. In particular, it was intended to modify the assumption that error detection time and correction time are independent in the software reliability growth model considering the existing error correction time, and to establish a general framework model that expresses the correlation between error detection time and correction time to determine when the software will be released. The results showed that it was important from an economic perspective to detect errors that took time to correct early in the test. It was concluded that it was very important to analyze the correlation between error detection time and error correction time in determining when to release the optimal software.

A Study on the Analysis of Errors occurred by Different Type of Automatic Bacteria Counting Equipments used in Counting Bacterial Number of Raw Milk (우유의 세균 자동측정장치의 오차범위 조사 및 오차발생 요인 분석에 관한 연구)

  • 정충일;엄양섭;김광태;강국희;이수원
    • Food Science of Animal Resources
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    • v.21 no.2
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    • pp.163-168
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    • 2001
  • This study was conducted to analyze the errors occurred between standard plate count(SPC) and Bactometer, Malthus, Bactoscan and to investigate correlation coefficient(r) between SPC and each equipments for the purpose of making new calibration curve. Correlation coefficients of three different types of equipments to SPC value were 0.71, 0.81, 0.84 respectively(n=287) and that of three types of equipments were 0.71∼0.82 relatively low. In raw milk, correlation coefficients of three types of equipments of SPC were in the range of 0.67∼0.73 below 3.0${\times}10^4$(CUF/ml) of bacterial number, and those between the three types of equipments were 0.68∼0.72. Between 3.0${\times}10^4$∼5.0${\times}10^5$(CFU/ml) of bacterial number, correlation coefficients of the three different types of equipments were 0.71∼0.81. and those between the three different types of equipments were 0.64∼0.77. Over 5.0${\times}10^5$(CFU/ml), correlation coefficient of the three types equipments were 0.66∼0.83 and those between them were 0.70∼0.85 respectively. The error of the three different types equipments to SPC value was significantly high, 37∼53% of them was under 50% of error range, and in case of raw milk less than 3.0${\times}10^4$ of bacterial number, 44∼67% of them showed over 100% of error.

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Generating Method of an Unambiguous Correlation Function for AltBOC Signal Tracking (AltBOC의 코드 추적을 위한 비모호 상관함수 생성 기법)

  • Woo, Sunghyuk;Chae, Keunhong;Lee, Seong Ro;Park, Soonyoung;Yoon, Seokho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.5
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    • pp.957-963
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    • 2015
  • The autocorrelation of an alternative binary offset carrier (AltBOC) signal provides an improved positioning accuracy because of its narrow main-peak. However, The AltBOC signal has a disadvantage that the autocorrelation of the AltBOC signal has multiple side-peaks which incur a severe positioning error. In this paper, we propose a generating method of an unambiguous correlation function for AltBOC signal tracking. Specifically, we first obtain symmetric partial correlation functions, and subsequently, we obtain an unambiguous correlation function by combining them. In numerical results, it is confirmed that the proposed correlation function provides better tracking error standard devation (TESD) performances comparing with the conventional correlation functions.

Pseudo-Correlation-Function Based Unambiguous Tracking Technique for CBOC (6,1,1/11) Signals

  • Jeong, Gil-Seop;Kong, Seung-Hyun
    • Journal of Positioning, Navigation, and Timing
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    • v.4 no.3
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    • pp.107-114
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    • 2015
  • Binary Offset Carrier (BOC) signal planned for future Global Navigation Satellite System (GNSS) provided better positioning accuracy and smaller multipath error than GPS C/A signal. However, due to the multiple side peaks in the auto-correlation function (ACF) of the BOC modulated signals, a receiver may false lock onto one of the side peaks in the tracking mode. This false lock would then result in a fatal tracking error. In this paper, we propose an unambiguous tracking method for composite BOC (CBOC) signals to mitigate this problem. It aims to reduce the side peaks of the ACF of CBOC modulated signals. It is based on the combination of traditional CBOC correlation function (CF) and reference CF of unmodulated pseudo- random noise code (PRN code). First, we present that cross-correlation function (CCF) with unmodulated PRN code is close to the secondary peaks of the traditional CBOC. Then, we obtain an unambiguous correlation function by subtracting traditional CBOC ACF from these CFs. Finally, the tracking performance for the CBOC signals is examined, and it is shown that the proposed method has better performance than the traditional unambiguous tracking method in additive white Gaussian noise (AWGN) channel.