• 제목/요약/키워드: Variance Values

검색결과 1,034건 처리시간 0.023초

pH 적정공정의 모델링 및 자기동조 제어기 설계 (Modelling of a pH titration process and design of a self-tuning pH controller)

  • 김우태;이혁희;최태호;이지태
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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    • pp.476-481
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    • 1988
  • In this paper a pH process of a weak acid with a strong base is modeled into a bilinear form, and a self-tuning pH control algorithm which is robust against initial values of solution and disturbances is presented. The control algorithm employs the recursive least square method for the parameter estimation and the generalised minimum variance criterion as the objective function. The computer simulation shows that the tracking of desired pH values is obtained in satisfactory manner regardless of the initial values chosen for the process.

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Genetic parameters for marbling and body score in Anglonubian goats using Bayesian inference via threshold and linear models

  • Figueiredo Filho, Luiz Antonio Silva;Sarmento, Jose Lindenberg Rocha;Campelo, Jose Elivalto Guimaraes;de Oliveira Almeida, Marcos Jacob;de Sousa, Antonio Junior;da Silva Santos, Natanael Pereira;da Silva Costa, Marcio;Torres, Tatiana Saraiva;Sena, Luciano Silva
    • Asian-Australasian Journal of Animal Sciences
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    • 제31권9호
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    • pp.1407-1414
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    • 2018
  • Objective: The aim of this study was to estimate (co) variance components and genetic parameters for categorical carcass traits using Bayesian inference via mixed linear and threshold animal models in Anglonubian goats. Methods: Data were obtained from Anglonubian goats reared in the Brazilian Mid-North region. The traits in study were body condition score, marbling in the rib eye, ribeye area, fat thickness of the sternum, hip height, leg perimeter, and body weight. The numerator relationship matrix contained information from 793 animals. The single- and two-trait analyses were performed to estimate (co) variance components and genetic parameters via linear and threshold animal models. For estimation of genetic parameters, chains with 2 and 4 million cycles were tested. An 1,000,000-cycle initial burn-in was considered with values taken every 250 cycles, in a total of 4,000 samples. Convergence was monitored by Geweke criteria and Monte Carlo error chain. Results: Threshold model best fits categorical data since it is more efficient to detect genetic variability. In two-trait analysis the contribution of the increase in information and the correlations between traits contributed to increase the estimated values for (co) variance components and heritability, in comparison to single-trait analysis. Heritability estimates for the study traits were from low to moderate magnitude. Conclusion: Direct selection of the continuous distribution of traits such as thickness sternal fat and hip height allows obtaining the indirect selection for marbling of ribeye.

인산염 이온 형태에 의한 pH 변량 모형 (pH Variance Model Depending on Phosphate Ion Form)

  • 소재우;소순일;남상용
    • 원예과학기술지
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    • 제33권6호
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    • pp.854-859
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    • 2015
  • 본 시험은 배양액 내 pH 변화에 따른 이온과 EC의 모형을 구명하고자 수행하였다. 배양액 내 $HPO_4{^{-2}}$$H_2PO_4{^-}$의 변량에 따른 pH가 변하는데, pH 4.0-5.0은 EC의 변량이 상승하고, pH 5.0-7.0은 EC의 변량이 완만하고, pH 7.0-8.0은 다시 상승하였다. 배양액 내 다량원소의 변량을 보면, pH가 상승할수록 K, Ca, N, P의 이온 농도도 증가하는데, 특히 K과 P의 변량이 크게 나타났다. 반면 Mg와 S의 변량은 일정하게 유지되었다. 배양액의 IBM(ion balance model)에 따른 분석에서, EC의 변량은 크게 변하지 않고, 이온의 균형점이 a분면에서 d분면으로 이동하면 pH가 상승하면서 음이온 보다 양이온이 증가하는 것으로 나타났다. 또한 pH 변량이 높을수록 EC 중앙선으로부터 멀어져 배양액의 이온 불균형이 증가되었다. $HPO_4{^{-2}}$$H_2PO_4{^-}$의 변량에 대한 K와 Ca의 당량비 보정은 pH가 증가할수록 K는 감소하지만 Ca는 증가하였고, EC 변량의 영향보다 큰 것으로 나타났다. K와 Ca의 당량비 보정에 따른 pH 변량은 0.97의 이차 다항식 상관모형을 나타냈다. 본 연구를 통해 인산염의 구배에 따른 pH, 이온, EC의 변량에 대하여 pH 변량 모형이 구명되었다.

주성분 분석을 이용한 홍삼의 내부품질과 자기공명특성 분석 (Analysis of Internal Quality and Magnetic Resonance Characteristics of Red Ginseng Using PCA)

  • 김성민;김철수
    • Journal of Biosystems Engineering
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    • 제28권3호
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    • pp.261-268
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    • 2003
  • Ten MHz pulsed NMR spectrometer was used to measure the magnetic resonance characteristics of Korean red ginseng. The difference in the internal structures of good and bad red ginsengs was examined by their NMR characteristics. Average values of $T_1$ and free induction decay(FID) ratios of under grade Korean red ginseng were the highest among the three groups categorized as normal, medium and under grades Korean red ginseng and average values of $T_2$ and $T_2$$^{*}$ of them were the lowest among the three groups. Principal component analysis(PCA) was used to observe the contribution of measured NMR values to the grade of Korean red ginseng. The measured $T_1$, $T_2$, $T_2$$^{*}$ and FID ratio of 79 Korean red ginsengs classified as normal grade, medium grade and under grade were examined using PCA analysis. Cumulative variance of PC1 through PC3 occupied more than 90% of total variance at first and second NMR measurement. Plots of PC scores for the most important PCs showed that normal red ginseng samples were distributed around the left region of PC1 axis and most of the undergrade red ginseng samples were scattered around the right region of PC1 axis.

윷놀이에서 말이 가는 거리의 분포 (A study on the distribution of the distance of Mal movement in Yut board game)

  • 김도형;오창혁
    • Journal of the Korean Data and Information Science Society
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    • 제21권6호
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    • pp.1281-1288
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    • 2010
  • 한 조로 사용 되는 네 개의 윷가지의 크기와 모양이 같아서 각 윷가지의 등이 나올 확률이 같은 윷놀이를 생각한다. 윷놀이에서는 모나 윷이 나오면 한 번 더 던지는 규칙이 있으므로, 한 사람의 차례에서 윷을 던져 말이 가는 거리 X에 관심이 있게 된다. 따라서, 거리 X에 대한 확률질량함수를 구하고, 각 윷가락의 등이 나올 확률의 몇 개의 값에 대하여 확률을 표로 나타낸다. 또한, 거리 X의 기댓값, 분산, 왜도, 첨도를 구하며, 주어진 윷의 등의 확률의 몇 개 값에 대하여 값을 구하여 표로 나타낸다.

Character Classification with Triangular Distribution

  • Yoo, Suk Won
    • International Journal of Advanced Culture Technology
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    • 제7권2호
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    • pp.209-217
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    • 2019
  • Due to the development of artificial intelligence and image recognition technology that play important roles in the field of 4th industry, office automation systems and unmanned automation systems are rapidly spreading in human society. The proposed algorithm first finds the variances of the differences between the tile values constituting the learning characters and the experimental character and then recognizes the experimental character according to the distribution of the three learning characters with the smallest variances. In more detail, for 100 learning data characters and 10 experimental data characters, each character is defined as the number of black pixels belonging to 15 tile areas. For each character constituting the experimental data, the variance of the differences of the tile values of 100 learning data characters is obtained and then arranged in the ascending order. After that, three learning data characters with the minimum variance values are selected, and the final recognition result for the given experimental character is selected according to the distribution of these character types. Moreover, we compare the recognition result with the result made by a neural network of basic structure. It is confirmed that satisfactory recognition results are obtained through the processes that subdivide the learning characters and experiment characters into tile sizes and then select the recognition result using variances.

Contribution of local site-effect on the seismic response of suspension bridges to spatially varying ground motions

  • Adanur, Suleyman;Altunisik, Ahmet C.;Soyluk, Kurtulus;Dumanoglu, A. Aydin;Bayraktar, Alemdar
    • Earthquakes and Structures
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    • 제10권5호
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    • pp.1233-1251
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    • 2016
  • In this paper, it is aimed to determine the stochastic response of a suspension bridge subjected to spatially varying ground motions considering the geometric nonlinearity. Bosphorus Suspension Bridge built in Turkey and connects Europe to Asia in Istanbul is selected as a numerical example. The spatial variability of the ground motion is considered with the incoherence, wave-passage and site-response effects. The importance of site-response effect which arises from the difference in the local soil conditions at different support points of the structure is also investigated. At the end of the study, mean of the maximum and variance response values obtained from the spatially varying ground motions are compared with those of the specialised cases of the ground motion model. It is seen that each component of the spatially varying ground motion model has important effects on the dynamic behaviour of the bridge. The response values obtained from the general excitation case, which also includes the site-response effect causes larger response values than those of the homogeneous soil condition cases. The variance values calculated for the general excitation case are dominated by dynamic component at the deck and Asian side tower. The response values obtained for the site-response effect alone are larger than the response values obtained for the incoherence and wave-passage effects, separately. It can be concluded that suspension bridges are sensitive to the spatial variability of ground motion. Therefore, the incoherence, the wave-passage and especially the site-response effects should be considered in the stochastic analysis of this type of engineering structures.

Grouping the Range Blocks Depending on the Variance Coherence

  • Lee, Yun-Jung;Kim, Young-Bong
    • 한국멀티미디어학회논문지
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    • 제7권12호
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    • pp.1665-1670
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    • 2004
  • The general fractal image compression provides a high compression rate, but it requires a large encoding time. In order to overcome this disadvantage, many researchers have introduced various methods that reduce the total number of domain blocks considering their block similarities or control the number of searching domain block depending on its distribution. In this paper, we propose a method that can reduce the number of searching domain blocks employing the variance coherence of intensity values and also the number of range blocks requiring the domain block search through the classification of range blocks. This proposed method effectively reduces the encoding time and also a negligible drop of the quality as compared with the previous methods requiring the search of all range blocks.

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웨이브렛을 이용한 공간적 영역분할에 의한 얼굴 인식 (Wavelet-Based Face Recognition by Divided Area)

  • 이성록;이상효;조창호;조도현;이상철
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.2307-2310
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    • 2003
  • In this paper, a method for face recognition based on the wavelet packet decomposition is proposed. In the proposed method, the input image is decomposed by the 2-level wavelet packet transformation and then the face areas are defined by the Integral Projection technique applied to each of the 1-level subband images, HL and LH. After the defined face areas are divided into three areas, called top, bottom, and border, the mean and the variance of the three areas of the approximation image are computed, and the variance of the single predetermined face area for the rest of 15 detail images, from which the feature vectors of statistical measure are extracted. In this paper we use the wavelet packet decomposition, a generalization of the classical wavelet decomposition, to obtain its richer signal analysis features such as discontinuity in higher derivatives, self-similarity, etc. And we have shown that even with very simple statistical features such as mean values and variance we can make an excellent basis for face classification, if an appropriate probability distance is used.

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최우도 모형을 이용한 수위-유량곡선식 개발 (Development of Rating Curves Using a Maximum Likelihood Model)

  • 김경훈;박준일;신찬기
    • 환경위생공학
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    • 제23권4호
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    • pp.83-93
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    • 2008
  • The non-linear least squares model(NLSM) has long been the standard technique used by hydrologists for constructing rating curves. The reasons for its adaptation are vague, and its appropriateness as a method of describing discharge measurement uncertainty has not been well investigated. It is shown in this paper that the classical method of NLSM can model only a very limited class of variance heterogeneity. Furthermore, this lack of flexibility often leads to unaccounted heteroscedasticity, resulting in dubious values for the rating curve parameters and estimated discharge. By introducing a heteroscedastic maximum likelihood model(HMLM), the variance heterogeneity is treated more generally. The maximum likelihood model stabilises the variance better than the NLSM approach, and thus is a more robust and appropriate way to fit a rating curve to a set of discharge measurements.