• Title/Summary/Keyword: Error Estimates

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LACTATION CURVE OF HOLSTEIN FRIESIAN COWS IN THE KINGDOM OF SAUDI ARABIA

  • Ali, A.K.A.;Al-Jumaah, R.S.;Hayes, E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.4
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    • pp.439-447
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    • 1996
  • Monthly test day production for 12,020 records, were collected from six of the largest specialized dairy farms located in central region of the Kingdom of Saudi Arabia. The records described lactating cows in four parities and two seasons of calving. Monthly test day records were fitted using Wood's model $At{{^b}{_e}}^{-ct}$ with multiple and additive error term. Linear and non-linear regression models were used to find the estimates of the parameters necessary to draw the lactation curves. The shape of the lactation curves of different parities showed that third lactation has the heighest peak (43.08 kg) for linear regression model and (42.08 kg) for non-linear regression model. Fourth lactation has the lowest peak (24.00kg) for linear regression model and (25.64 kg) for non-linear regression models. Cows of second and third lactations reached the peak at 58 day for both linear and non-linear regression models. Cows of first lactation were more persistent and had late peak at 68 and 67 days for both models respectively. While, third lactation cows were lower persistent and had early peak at 58 day for both models. Cows calved at winter months have higher starting values (A), higher ascending slope (b) and higher decending slope (c). Least square means of milk yield of the first four parities and for overall data were 6,653, 7,659, 7,482, 6,988 and 7,614 kg respectively. The corresponding lactation period were 358, 367, 350, 363 and 364 days respectively.

A Study on the Preprocessing Method Using Construction of Watershed for Character Image segmentation

  • Nam Sang Yep;Choi Young Kyoo;Kwon Yun Jung;Lee Sung Chang
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.814-818
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    • 2004
  • Off-line handwritten character recognition is in difficulty of incomplete preprocessing because it has not dynamic and timing information besides has various handwriting, extreme overlap of the consonant and vowel and many error image of stroke. Consequently off-line handwritten character recognition needs to study about preprocessing of various methods such as binarization and thinning. This paper considers running time of watershed algorithm and the quality of resulting image as preprocessing For off-line handwritten Korean character recognition. So it proposes application of effective watershed algorithm for segmentation of character region and background region in gray level character image and segmentation function for binarization image and segmentation function for binarization by extracted watershed image. Besides it proposes thinning methods which effectively extracts skeleton through conditional test mask considering running time and quality. of skeleton, estimates efficiency of existing methods and this paper's methods as running time and quality. Watershed image conversion uses prewitt operator for gradient image conversion, extracts local minima considering 8-neighborhood pixel. And methods by using difference of mean value is used in region merging step, Converted watershed image by means of this methods separates effectively character region and background region applying to segmentation function. Average execution time on the previous method was 2.16 second and on this paper method was 1.72 second. We prove that this paper's method removed noise effectively with overlap stroke as compared with the previous method.

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Efficient Blind Maximal Ratio Combining Methods for Digital Communication Systems (디지탈 통신 시스템을 위한 효율적인 블라인드 최대비 결합 방법)

  • Oh, Seong-Keun
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.11
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    • pp.1-11
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    • 1998
  • We present somple block methods for blind maximal ratio combining (MRC) based on a maximum likelihood (ML) principle and finite alphabet properties (FAP) inherent in digital communication systems. The methods can provide accurate estimates of channel parameters even with a small subset of data, thus realizing nearly perfect combining. The channel parameters of diversity branches and the data sequence are estimated simultaneously by using an alternating projection technique. Two different methods, that is, (1) Joint combining and data sequence estimation(JC-DSE) method and (2) Pre-combining and blind phase estimation (PC-BPE) method are presented. Efficient initiallization schemes that can assure the convergence to the global optimum are also presented. Simulation results demonstrate the performance of two methods on the symbol error rate (SER) and the estimated accuracy of the channel parameters.

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On Estimating Position and Velocity of Mobile Stations by Path-loss Data Base in a Cellular System (셀룰라 이동 통신 시스템에서 경로손실 데이터 베이스를 이용한 이동국의 위치와 속도 추정 방식)

  • Lee, Sang-Hun;Chung, Woo-Gon;Choi, Hyung-Jin
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.11
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    • pp.19-27
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    • 1998
  • To achieve the required services in the next-generation cellular telephone systems, the size of the cell become smaller and/or is of mixed macrocells and microcells. For more efficient system control, We make use of the mobile position and velocity information, provided that the mobility information is relatively accurate. In this paper, we propose an improved version of path-loss measurement algorithm introduced in literature[11]. The microcellular structure with severe multipath fading, reflection and refraction make mobile position and velocity estimation very difficult. In the proposed method, the pre-recorded path-loss informations, called the discrete position data base, are searched to estimate the position. Velocity estimation is obtained as a difference of the position values with respect to the time difference. Moving average filter is applied to smooth the estimated velocity and to reduce the error in the estimates. We also propose a method to simplify system implementation by reducing search area for discrete area database.

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Optimization of the Gain Parameters in a Tracking Module for ARPA system on Board High Dynamic Warships

  • Pan, Bao-Feng;Njonjo, Anne Wanjiru;Jeong, Tae-Gweon
    • Journal of Navigation and Port Research
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    • v.40 no.5
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    • pp.241-247
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    • 2016
  • The tracking filter plays a key role in the accurate estimation and prediction of maneuvering a vessel's position and velocity when attempting to enhance safety by avoiding collision. Therefore, in order to achieve accurate estimation and prediction, many oceangoing vessels are equipped with the Automatic Radar Plotting Aid (ARPA) system. However, the accuracy of prediction depends on the tracking filter's ability to reduce noise and maintain a stable transient response. The purpose of this paper is to derive the optimal values of the gain parameters used in tracking a High Dynamic Warship. The algorithm employs a ${\alpha}-{\beta}-{\gamma}$ filter to provide accurate estimates and updates of the state variables, that is, positions, velocity and acceleration of the high dynamic warship based on previously observed values. In this study, the filtering coefficients ${\alpha}$, ${\beta}$ and ${\gamma}$ are determined from set values of the damping parameter, ${\xi}$. Optimization of the damping parameter, ${\xi}$, is achieved experimentally by plotting the residual error against different values of the damping parameter to determine the least value of the damping parameter that results in the optimum smoothing coefficients leading to a reduction in the noise corruption effect. Further investigation of the performance of the filter indicates that optimal smoothing coefficients depend on the initial and average velocity of the target.

Sample Size and Statistical Power Calculation in Genetic Association Studies

  • Hong, Eun-Pyo;Park, Ji-Wan
    • Genomics & Informatics
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    • v.10 no.2
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    • pp.117-122
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    • 2012
  • A sample size with sufficient statistical power is critical to the success of genetic association studies to detect causal genes of human complex diseases. Genome-wide association studies require much larger sample sizes to achieve an adequate statistical power. We estimated the statistical power with increasing numbers of markers analyzed and compared the sample sizes that were required in case-control studies and case-parent studies. We computed the effective sample size and statistical power using Genetic Power Calculator. An analysis using a larger number of markers requires a larger sample size. Testing a single-nucleotide polymorphism (SNP) marker requires 248 cases, while testing 500,000 SNPs and 1 million markers requires 1,206 cases and 1,255 cases, respectively, under the assumption of an odds ratio of 2, 5% disease prevalence, 5% minor allele frequency, complete linkage disequilibrium (LD), 1:1 case/control ratio, and a 5% error rate in an allelic test. Under a dominant model, a smaller sample size is required to achieve 80% power than other genetic models. We found that a much lower sample size was required with a strong effect size, common SNP, and increased LD. In addition, studying a common disease in a case-control study of a 1:4 case-control ratio is one way to achieve higher statistical power. We also found that case-parent studies require more samples than case-control studies. Although we have not covered all plausible cases in study design, the estimates of sample size and statistical power computed under various assumptions in this study may be useful to determine the sample size in designing a population-based genetic association study.

A Study on the Simplification of Quantity Calculation of Reinforcing Bar (철근 수량산출 간소화 방안)

  • Jo, Yeong-Ho;Yun, Seok-Heon
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.6
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    • pp.521-527
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    • 2019
  • Quantity takeoff and cost estimates in Korea are carried out in practice without any clear standards or standards. Especially, quantity takeoff of Reinforcing bar and BoQ documentation process is very complex using 2D drawings. In this study, 10 case sites were analyzed for the status of inefficient quantity takeoff and how the statement was prepared. In order to solve this problem, this study presented a method for calculating the quantity of rebars through the ratio of concrete volume for schools, offices, and apartment buildings, and analyzed the accuracy of results. In the future, it is expected that the error range can be reduced by defining the factors affecting the results and calculating the correction value for them.

Rapid Diagnosis of CMT1A Duplications and HNPP Deletions by Multiplex Microsatellite PCR

  • Choi, Byung-Ok;Kim, Joonki;Lee, Kyung Lyong;Yu, Jin Seok;Hwang, Jung Hee;Chung, Ki Wha
    • Molecules and Cells
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    • v.23 no.1
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    • pp.39-48
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    • 2007
  • Charcot-Marie-Tooth (CMT) disease and hereditary neuropathy with liability to pressure palsies (HNPP) are frequent forms of genetically heterogeneous peripheral neuropathies. Reciprocal unequal crossover between flanking CMT1A-REPs on chromosome 17p11.2-p12 is a major cause of CMT type 1A (CMT1A) and HNPP. The importance of a sensitive and rapid method for identifying the CMT1A duplication and HNPP deletion is being emphasized. In the present study, we established a molecular diagnostic method for the CMT1A duplication and HNPP deletion based on hexaplex PCR of 6 microsatellite markers (D17S921, D17S9B, D17S9A, D17S918, D17S4A and D17S2230). The method is highly time-, cost- and sample-saving because the six markers are amplified by a single PCR reaction and resolved with a single capillary in 3 h. Several statistical and forensic estimates indicated that most of these markers are likely to be useful for diagnosing the peripheral neuropathies. Reproducibility, as determined by concordance between independent tests, was estimated to be 100%. The likelihood that genotypes of all six markers are homozygous in randomly selected individuals was calculated to be $1.6{\times}10^{-4}$, which indicates that the statistical error rate for this diagnosis of HNPP deletion is only 0.016%.

An investigation of lead absorption in an electric accumulator factory with the use of personal samplers

  • Williams M.K.;King E.;Walford Joan
    • 대한예방의학회:학술대회논문집
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    • 1994.02a
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    • pp.561-575
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    • 1994
  • Williams, M K., King, E., and Walford, Joan (1969). Brit. J. industr. Med., 26, 202-216. An investigation of lead absorption in an electric accumulator factory with the use of personal samplers. Thirty-nine lead workers and controls, in stable conditions of exposure, each wore personal lead-in-air samplers daily for two weeks. During the second week samples for blood lead, urinary lead, urinary coproporphyrin, urinary $\gamma$-aminolevulinic acid (ALA), the punctate basophil count, and haemoglobin were taken daily. Duplicate estimations were made on one day. The lead exposures of men doing almost identical jobs differed by ratios of up to four to one. This could be attributed on y to personal differences in working habits. The correlation coefficients and regression equations of the biochemical tests with lead-in-air and with each other were determined. The mean values and $95\%$ confidence limits of single determinations of some of the biochemical tests corresponding to the two commonly accepted TLVs of lead-in-air (0-20 and 0-15 mg./$m^{3}$) were calculated from the regression equations. For each biochemical test the variation due to analytical error, the variation from day to day within subjects and the residual variation about the regression on lead-in-air were calculated. Previous estimates of the latter are not known. Excessive confidence may be placed in an index of exposure due to its low coefficient of variation within subjects unless the coefficient of variation between subjects about regression is taken into account. The correction for specific gravity of estimations of lead and ALA in spot samples of urine was found to reduce slightly the residual variation between subjects about the regression on lead-in-air and to increase the correlations with lead-in-air and with the other biochemical tests, but these changes were not statistically significant. The modified method used for estimating blood lead and urinary lead is described and validated.

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Investigating the scaling effect of the nonlinear response to precipitation forcing in a physically based hydrologic model (강우자료의 스케일 효과가 비선형수문반응에 미치는 영향)

  • Oh, Nam-Sun;Lee, K.
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.149-153
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    • 2006
  • Precipitation is the most important component and critical to the study of water and energy cycle. This study investigates the propagation of precipitation retrieval uncertainty in the simulation of hydrologic variables for varying spatial resolution on two different vegetation cover. We explore two remotely sensed rain retrievals (space-borne IR-only and radar rainfall) and three spatial grid resolutions. An offline Community Land Model (CLM) was forced with in situ meteorological data In turn, radar rainfall is replaced by the satellite rain estimates at coarser resolution $(0.25^{\circ},\;0.5^{\circ}\;and\;1^{\circ})$ to determine their probable impact on model predictions. Results show how uncertainty of precipitation measurement affects the spatial variability of model output in various modelling scales. The study provides some intuition on the uncertainty of hydrologic prediction via interaction between the land surface and near atmosphere fluxes in the modelling approach.

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