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Artykuły w czasopismach na temat "Regression of Proportion"
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Wang, Jin, Aizhi Sun, Qian Gao, Fuqiang Zhai, Shen Wu i Alex A. Volinsky. "Slag material's proportion optimised by polynomial regression". Proceedings of the Institution of Civil Engineers - Construction Materials 167, nr 1 (luty 2014): 8–13. http://dx.doi.org/10.1680/coma.12.00003.
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Milicevic, Mario, Vedran Batos, Adriana Lipovac i Zeljka Car. "Deep Regression Neural Networks for Proportion Judgment". Future Internet 14, nr 4 (23.03.2022): 100. http://dx.doi.org/10.3390/fi14040100.
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Deep regression models are widely employed to solve computer vision tasks, such as human age or pose estimation, crowd counting, object detection, etc. Another possible area of application, which to our knowledge has not been systematically explored so far, is proportion judgment. As a prerequisite for successful decision making, individuals often have to use proportion judgment strategies, with which they estimate the magnitude of one stimulus relative to another (larger) stimulus. This makes this estimation problem interesting for the application of machine learning techniques. In regard to this, we proposed various deep regression architectures, which we tested on three original datasets of very different origin and composition. This is a novel approach, as the assumption is that the model can learn the concept of proportion without explicitly counting individual objects. With comprehensive experiments, we have demonstrated the effectiveness of the proposed models which can predict proportions on real-life datasets more reliably than human experts, considering the coefficient of determination (>0.95) and the amount of errors (MAE < 2, RMSE < 3). If there is no significant number of errors in determining the ground truth, with an appropriate size of the learning dataset, an additional reduction of MAE to 0.14 can be achieved. The used datasets will be publicly available to serve as reference data sources in similar projects.
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Han, Bing, i Nelson Lim. "Estimating conditional proportion curves by regression residuals". Statistics in Medicine 29, nr 13 (23.03.2010): 1443–54. http://dx.doi.org/10.1002/sim.3889.
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Lee, Dong-Hee. "Regression Models for Bivariate Semi-continuous Proportion Data". Korean Data Analysis Society 19, nr 2 (30.04.2017): 663–73. http://dx.doi.org/10.37727/jkdas.2017.19.2.663.
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Naik, V. D., i P. C. Gupta. "On regression method for estimating a population proportion". Statistical Papers 37, nr 1 (marzec 1996): 85–92. http://dx.doi.org/10.1007/bf02926162.
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Galvis, Diana M., Dipankar Bandyopadhyay i Victor H. Lachos. "Augmented mixed beta regression models for periodontal proportion data". Statistics in Medicine 33, nr 21 (24.04.2014): 3759–71. http://dx.doi.org/10.1002/sim.6179.
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Shim, Jooyong, i Changha Hwang. "Geographically weighted kernel logistic regression for small area proportion estimation". Journal of the Korean Data and Information Science Society 27, nr 2 (31.03.2016): 531–38. http://dx.doi.org/10.7465/jkdi.2016.27.2.531.
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Zhang, L., B. Wu, B. Huang i P. Li. "Nonlinear estimation of subpixel proportion via kernel least square regression". International Journal of Remote Sensing 28, nr 18 (23.08.2007): 4157–72. http://dx.doi.org/10.1080/01431160600993454.
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Martínez, Sergio, Maria Rueda, Antonio Arcos i Helena Martínez. "Estimating the Proportion of a Categorical Variable With Probit Regression". Sociological Methods & Research 49, nr 3 (8.03.2018): 809–34. http://dx.doi.org/10.1177/0049124118761771.
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This article discusses the estimation of a population proportion, using the auxiliary information available, which is incorporated into the estimation procedure by a probit model fit. Three probit regression estimators are considered, using model-based and model-assisted approaches. The theoretical properties of the proposed estimators are derived and discussed. Monte Carlo experiments were carried out for simulated data and for real data taken from a database of confirmed dengue cases in Mexico. The probit estimates give valuable results in comparison to alternative estimators. Finally, the proposed methodology is applied to data obtained from an immigration survey.
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Parker, Anthony J., Dipankar Bandyopadhyay i Elizabeth H. Slate. "A spatial augmented beta regression model for periodontal proportion data". Statistical Modelling: An International Journal 14, nr 6 (25.09.2014): 503–21. http://dx.doi.org/10.1177/1471082x14535515.
Pełny tekst źródłaRozprawy doktorskie na temat "Regression of Proportion"
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Miyashiro, Eliane Shizue. "Modelos de regressão beta e simplex para análise de proporções". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-06112009-224039/.
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Diversos estudos compreendem a análise de variáveis definidas no intervalo (0, 1), como porcentagens ou proporções. Os modelos mais adequados são os de regressão baseados nas distribuições beta e simplex. Neste trabalho, apresentamos o modelo de regressão beta proposto por Ferrari & Cribari-Neto (2004) e desenvolvemos o modelo de regressão simplex. Definimos um resíduo para o modelo de regressão simplex, muito útil na análise de diagnóstico, a partir do trabalho de Espinheira, Ferrari & Cribari-Neto (2008). Apresentamos uma forma geral para algumas medidas de diagnóstico, que podem ser aplicadas para os dois modelos. Avaliamos os modelos de regressão beta e simplex por meio de duas aplicações a dados reais, utilizando essas medidas.Many studies consider the analysis of variables restricted to the interval (0, 1), as percentages and proportions. The most recommended models are based upon the beta and simplex distributions. In this work, we present the beta regression model proposed by Ferrari and Cribari-Neto (2004) and develop the simplex regression model. We propose a residual for the simplex regression model, which is very useful for the diagnostic analysis, based upon the work of Espinheira et al. (2008). We generalize some diagnostic techniques that can be applied to both models. We evaluate the beta and simplex models by two applications to real data, using those techniques.
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Forslind, Fanni. "The Effect of Immigration on Income Distribution : A Comparative Study of Ordinary Least Squares and Beta Regression". Thesis, Uppsala universitet, Statistiska institutionen, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-433098.
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The purpose of this study is to estimate the relationship between income inequality and immigration in Sweden. To do so, data from the data base Kolada with observations from all 290 municipalities in Sweden is used. As a proxy for income distribution the Gini coefficient is used and as a proxy for immigration the share of foreign born of working age is used. The model also controls for income tax, education level and unemployment level. The dependent variable the Gini coefficient is bounded by a unit interval and it is therefore not possible to simply run a linear regression. Such a model could potentially predict outside the interval. To properly estimate the relationship two approaches are made. Firstly a model is estimated with Ordinary Least Squares (OLS) after the dependent variable is transformed on to the real line through log-odds. Then a model is estimated using beta regression. The study concludes that there is a statistically significant positive correlation between income inequality and immigration in Sweden. The OLS estimated model shows that a 1 unit increase in immigration, on average increases the log-odds of 0.28336 units, ceteris paribus. Beta regression provides perhaps more intuitive results. If immigration increases with 1% the income inequality increases with on average 0.1046%, ceteris paribus. Because of the easier interpretation, among other things, beta regression is determined to be a better estimation method in this study.
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Cribari-Neto, Francisco, i Achim Zeileis. "Beta Regression in R". Department of Statistics and Mathematics x, WU Vienna University of Economics and Business, 2009. http://epub.wu.ac.at/726/1/document.pdf.
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The class of beta regression models is commonly used by practitioners to model variables that assume values in the standard unit interval (0, 1). It is based on the assumption that the dependent variable is beta-distributed and that its mean is related to a set of regressors through a linear predictor with unknown coefficients and a link function. The model also includes a precision parameter which may be constant or depend on a (potentially different) set of regressors through a link function as well. This approach naturally incorporates features such as heteroskedasticity or skewness which are commonly observed in data taking values in the standard unit interval, such as rates or proportions. This paper describes the betareg package which provides the class of beta regressions in the R system for statistical computing. The underlying theory is briefly outlined, the implementation discussed and illustrated in various replication exercises.Series: Research Report Series / Department of Statistics and Mathematics
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LEAL, ALTURO Olivia Lizeth. "Nonnested hypothesis testing inference in regression models for rates and proportions". Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/24573.
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Existem diferentes modelos de regressão que podem ser usados para modelar taxas, proporções e outras variáveis respostas que assumem valores no intervalo unitário padrão, (0,1). Quando só uma classe de modelos de regressão é considerada, a seleção do modelos pode ser baseada nos testes de hipóteses usuais. O objetivo da presente dissertação é apresentar e avaliar numericamente os desempenhos em amostras imitas de testes que podem ser usados quando há dois ou mais modelos que são plausíveis, são não-encaixados e pertencem a classes de modelos de regressão distintas. Os modelos competidores podem diferir nos regressores que utilizam, nas funções de ligação e/ou na distribuição assumida para a variável resposta. Através de simulações de Monte Cario nós estimamos as taxas de rejeição nulas e não-nulas dos testes sob diversos cenários. Avaliamos também o desempenho de um procedimento de seleção de modelos. Os resultados mostram que os testes podem ser bastante úteis na escolha do melhor modelo de regressão quando a variável resposta assume valores no intervalo unitário padrão.
There are several different regression models that can be used with rates, proportions and other continuous responses that assume values in the standard unit interval, (0,1). When only one class of models is considered, model selection can be based on standard hypothesis testing inference. In this dissertation, we develop tests that can be used when the practitioner has at his/her disposal more than one plausible model, the competing models are nonnested and possibly belong to different classes of models. The competing models can differ in the regressors they use, in the link functions and even in the response distribution. The finite sample performances of the proposed tests are numerically eval-uated. We evaluate both the null and nonnull behavior of the tests using Monte Cario simulations. The results show that the tests can be quite useful for selecting the best regression model when the response assumes values in the standard unit interval.
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Persson, Inger. "Essays on the Assumption of Proportional Hazards in Cox Regression". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2002. http://publications.uu.se/theses/91-554-5208-6/.
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Crumer, Angela Maria. "Comparison between Weibull and Cox proportional hazards models". Kansas State University, 2011. http://hdl.handle.net/2097/8787.
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Master of ScienceDepartment of Statistics
James J. Higgins
The time for an event to take place in an individual is called a survival time. Examples include the time that an individual survives after being diagnosed with a terminal illness or the time that an electronic component functions before failing. A popular parametric model for this type of data is the Weibull model, which is a flexible model that allows for the inclusion of covariates of the survival times. If distributional assumptions are not met or cannot be verified, researchers may turn to the semi-parametric Cox proportional hazards model. This model also allows for the inclusion of covariates of survival times but with less restrictive assumptions. This report compares estimates of the slope of the covariate in the proportional hazards model using the parametric Weibull model and the semi-parametric Cox proportional hazards model to estimate the slope. Properties of these models are discussed in Chapter 1. Numerical examples and a comparison of the mean square errors of the estimates of the slope of the covariate for various sample sizes and for uncensored and censored data are discussed in Chapter 2. When the shape parameter is known, the Weibull model far out performs the Cox proportional hazards model, but when the shape parameter is unknown, the Cox proportional hazards model and the Weibull model give comparable results.
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Maier, Marco J. "DirichletReg: Dirichlet Regression for Compositional Data in R". WU Vienna University of Economics and Business, 2014. http://epub.wu.ac.at/4077/1/Report125.pdf.
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Dirichlet regression models can be used to analyze a set of variables lying
in a bounded interval that sum up to a constant (e.g., proportions, rates,
compositions, etc.) exhibiting skewness and heteroscedasticity, without
having to transform the data.
There are two parametrization for the presented model, one using the common
Dirichlet distribution's alpha parameters, and a reparametrization of the
alpha's to set up a mean-and-dispersion-like model.
By applying appropriate link-functions, a GLM-like framework is set up that
allows for the analysis of such data in a straightforward and familiar way,
because interpretation is similar to multinomial logistic regression.
This paper gives a brief theoretical foundation and describes the
implementation as well as application (including worked examples) of
Dirichlet regression methods implemented in the package DirichletReg (Maier,
2013) in the R language (R Core Team, 2013). (author's abstract)Series: Research Report Series / Department of Statistics and Mathematics
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Galvis, Soto Diana Milena 1978. "Bayesian analysis of regression models for proportional data in the presence of zeros and ones = Análise bayesiana de modelos de regressão para dados de proporções na presença de zeros e uns". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306682.
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Orientador: Víctor Hugo Lachos DávilaTese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica
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Resumo: Dados no intervalo (0,1) geralmente representam proporções, taxas ou índices. Porém, é possível observar situações práticas onde as proporções sejam zero e/ou um, representando ausência ou presença total da característica de interesse. Nesses casos, os modelos que analisam o efeito de covariáveis, tais como a regressão beta, beta retangular e simplex não são convenientes. Com o intuito de abordar este tipo de situações, considera-se como alternativa aumentar os valores zero e/ou um ao suporte das distribuições previamente mencionadas. Nesta tese, são propostos modelos de regressão de efeitos mistos para dados de proporções aumentados de zeros e uns, os quais permitem analisar o efeito de covariáveis sobre a probabilidade de observar ausência ou presença total da característica de interesse, assim como avaliar modelos com respostas correlacionadas. A estimação dos parâmetros de interesse pode ser via máxima verossimilhança ou métodos Monte Carlo via Cadeias de Markov (MCMC). Nesta tese, será adotado o enfoque Bayesiano, o qual apresenta algumas vantagens em relação à inferência clássica, pois não depende da teoria assintótica e os códigos são de fácil implementação, através de softwares como openBUGS e winBUGS. Baseados na distribuição marginal, é possível calcular critérios de seleção de modelos e medidas Bayesianas de divergência q, utilizadas para detectar observações discrepantes
Abstract: Continuous data in the unit interval (0,1) represent, generally, proportions, rates or indices. However, zeros and/or ones values can be observed, representing absence or total presence of a carachteristic of interest. In that case, regression models that analyze the effect of covariates such as beta, beta rectangular or simplex are not appropiate. In order to deal with this type of situations, an alternative is to add the zero and/or one values to the support of these models. In this thesis and based on these models, we propose the mixed regression models for proportional data augmented by zero and one, which allow analyze the effect of covariates into the probabilities of observing absence or total presence of the interest characteristic, besides of being possivel to deal with correlated responses. Estimation of parameters can follow via maximum likelihood or through MCMC algorithms. We follow the Bayesian approach, which presents some advantages when it is compared with classical inference because it allows to estimate the parameters even in small size sample. In addition, in this approach, the implementation is straightforward and can be done using software as openBUGS or winBUGS. Based on the marginal likelihood it is possible to calculate selection model criteria as well as q-divergence measures used to detect outlier observations
Doutorado
Estatistica
Doutora em Estatística
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Johnson, Edward P. "Applying Bayesian Ordinal Regression to ICAP Maladaptive Behavior Subscales". Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2121.pdf.
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Pereira, Gustavo Henrique de Araujo. "Modelos de regressão beta inflacionados truncados". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-14082012-123751/.
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Os modelos de regressão beta e beta inflacionados conseguem ajustar adequadamente grande parte das variáveis do tipo proporção. No entanto, esses modelos não são úteis quando a variável resposta não pode assumir valores no intervalo (0,c) e assume o valor c com probabilidade positiva. Variáveis relacionadas a algum tipo de pagamento limitado entre dois valores, quando estudadas em relação ao seu valor máximo, possuem essas características. Para ajustar essas variáveis, introduzimos a distribuição beta inflacionada truncada (BIZUT), que é uma mistura de uma distribuição beta com suporte no intervalo (c,1) e uma distribuição trinomial que assume os valores zero, um e c. Propomos ainda um modelo de regressão para as situações em que a variável resposta tem distribuição BIZUT. Admitimos que todos os parâmetros da distribuição podem variar em função de variáveis preditoras. Além disso, o modelo permite que o parâmetro conhecido c varie entre as unidades populacionais. Para esse modelo são desenvolvidos diversos aspectos inferenciais, são obtidos resultados para as situações em que c é variável e são conduzidos estudos de simulação de Monte Carlo. Além disso, discutimos análise de resíduos, desenvolvemos análise de influência local e realizamos uma aplicação a dados reais de cartão de crédito.The beta regression model or the inflated beta regression model may be a reasonable choice to fit a proportion in most situations. However, they do not fit well variables that do not assume values in the open interval (0,c), 0 < c < 1 and assume the c value with positive probability. Variables related to a kind of double bounded payment amount when studied as a proportion of the maximum payment amount have this feature. For these variables, we introduce the truncated inflated beta distribution (TBEINF). This proposed distribution is a mixture of the beta distribution bounded in the open interval (c,1) and a trinomial distribution that assumes the values zero, one and c. This work also proposes a regression model where the response variable is TBEINF distributed. The model allows all the unknown parameters of the conditional distribution of the response variable to be modeled as functions of explanatory variables. Moreover, the model allows nonconstant known parameter c across population units. For this model, some inferential aspects are developed, some results when c is not constant are obtained and Monte Carlo simulation studies are performed. In addition, residual and local influence analysis are discussed and an application to credit card data is presented.
Książki na temat "Regression of Proportion"
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O'Quigley, John. Proportional Hazards Regression. New York, NY: Springer New York, 2008. http://dx.doi.org/10.1007/978-0-387-68639-4.
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Tapia-Aguilar, Alberto. Accurate confidence intervals for regression parameters in proportional hazards model. Toronto: [s.n.], 1994.
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Spray, Judith A. Comparison of loglinear and logistic regression models for detecting changes in proportions. Iowa City: American College Testing Program, 1988.
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LeBlanc, Michael R. Step-function covariate effects in the proportional hazards model. Toronto, Ont: University of Toronto, Department of Statistics, 1993.
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O'Quigley, John. Proportional Hazards Regression. Springer New York, 2010.
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O'Quigley, John. Survival Analysis: Proportional and Non-Proportional Hazards Regression. Springer International Publishing AG, 2022.
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O'Quigley, John. Survival Analysis: Proportional and Non-Proportional Hazards Regression. Springer, 2021.
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Proportional Hazards Regression (Statistics for Biology and Health). Springer, 2008.
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O'Quigley, John. Proportional Hazards Regression (Statistics for Biology and Health). Springer, 2008.
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Persson, Inger. Essays on the Assumption of Proportional Hazards in Cox Regression. Uppsala Universitet, 2002.
Znajdź pełny tekst źródłaCzęści książek na temat "Regression of Proportion"
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García Portilla, Jason. "Component 1 (Macro): Quantitative (Regression) Analysis". W “Ye Shall Know Them by Their Fruits”, 211–31. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78498-0_15.
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AbstractThis chapter corresponds to the macro-quantitative component. It discusses how competitiveness and corruption were modelled, how the methods were applied in the correlation analysis and which empirical results were achieved.Regression analysis is used to test the relationship between variables of some prominent prosperity/corruption theories. This part does not seek to prove causation, but instead empirically explores whether competitiveness/transparency are related to indicators such as state religion or a population’s religious affiliation.Consistent results of the models on competitiveness (GCI) are: (1) a positive influence of EPI on GCI; (2) a positive influence of a German legal origin (or German language) on GCI; (3) a negative influence of an Orthodox population on GCI; and (4) a negative influence of a Roman Catholic population (or Roman Catholic State Religion) on GCI. These results are also consistent with the predictions in the theory chapters (Chaps. 10.1007/978-3-030-78498-0_6–10.1007/978-3-030-78498-0_11).The corruption model applied here tests the interrelations between GDP, political liberties (democracy proxy), and language and ethnic fractionalisation. The results of the models on corruption are entirely compatible with theory. The results confirm my hypothesis that transparency levels are directly (i.e. positively) related to the proportion of Protestants in countries in Europe and the Americas.
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Guo, Jiaxu, Shaowei Hu, Xuan Zhao, Xiu Tao i Ying Nie. "Compressive Strength Performance of Additives for Cement-Based Grouting Material with Low Water-Binder Ratio by Response Surface Methodology". W Lecture Notes in Civil Engineering, 368–79. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1260-3_34.
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AbstractIn order to research the influence and the function mechanism of calcium formate and defoaming agent on the compressive strength of cement-based grouting material with low water-binder ratio at different ages, quadratic polynomial regression models were established by RSM, and the mix proportion was optimized. The function mechanism of additives was analysed by macroscopic mechanical properties and microstructure. The results indicated that the response surface method is scientific in optimizing the mix proportion of cement-based grouting material. The optimal mix proportion was obtained as fallow: the calcium formate was 0.64%, the water-binder ratio was 0.21 and the defoaming agent was 0.26%, with taking 1d, 3d, 28d compressive strength as the optimization objective. Calcium formate is highly significant for the early compressive strength of cement-based grouting materials with low water-binder ratio, while the water-binder ratio and defoaming agent are highly significant for that of the middle and late period. Calcium formate promotes the formation of CSH gel and $$\mathrm{Ca}{\left(\mathrm{OH}\right)}_{2}$$ Ca OH 2 crystallization in the early period, and the defoaming agent can effectively reduce macropores. The results can provide an optimization method for the mix proportion design of cement-based grouting material and a theoretical reference for its mechanical properties.
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Harrell, Frank E. "Cox Proportional Hazards Regression Model". W Regression Modeling Strategies, 475–519. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19425-7_20.
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Harrell, Frank E. "Cox Proportional Hazards Regression Model". W Regression Modeling Strategies, 465–507. New York, NY: Springer New York, 2001. http://dx.doi.org/10.1007/978-1-4757-3462-1_19.
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Wang, Wei, i Chengcheng Hu. "Proportional Hazards Regression Models". W Springer Handbook of Engineering Statistics, 387–96. London: Springer London, 2006. http://dx.doi.org/10.1007/978-1-84628-288-1_21.
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Matthews, David Edward, i Vernon Todd Farewell. "13 Proportional Hazards Regression". W Using and Understanding Medical Statistics, 149–59. Basel: KARGER, 2007. http://dx.doi.org/10.1159/000099428.
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Riyanti, Novi Dwi, Werner R. Murhadi i Mudji Utami. "The Influence of Good Corporate Governance through the Gender Diversity on Firm Performance". W Proceedings of the 19th International Symposium on Management (INSYMA 2022), 5–12. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-008-4_2.
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AbstractThe objective of this study is to look at how board size, board gender diversity, independent commissioners, leverage, and firm size affect firm performance in manufacturing companies in Indonesia Stock Exchange and the Philippines Stock Exchange. This study used a quantitative approach with two least square regression analysis models and a sample of manufacturing sector companies listed on the Indonesia Stock Exchange and the Philippines Stock Exchange, with a total of 100 business entities and 480 observations. This study used the presence of female commissioners and the proportion of female commissioners to measure board gender diversity. According to the findings of this study, independent commissioners in Indonesia have a significantly positive effect on return on assets, female commissioners in Indonesia have a significant adverse effect on return on assets, and Tobin’s Q, both leverage in Indonesia and firm size in the Philippines have a significant adverse effect on return on assets. Meanwhile, leverage in Indonesia has a significant negative effect on Tobin’s Q, as does board size in Indonesia and firm size in Indonesia and the Philippines.
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Broström, Göran. "Proportional Hazards and Cox Regression". W Event History Analysis with R, 43–64. Wyd. 2. Boca Raton: Chapman and Hall/CRC, 2021. http://dx.doi.org/10.1201/9780429503764-3.
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Zang, Wanjun, i Jiang Wen. "Analysis of Slurry Ratio of Rotary Digging Pile in Deep Sand Layer". W Lecture Notes in Civil Engineering, 137–49. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1748-8_11.
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AbstractSlurry ratio is a crucial link in the construction of bored pile, which directly determines the quality of bored pile. In order to determine the key performance parameters of the slurry required to form piles in the deep sand layer, relying on Huizhou north station engineering, an orthogonal test of slurry proportioning was designed and carried out, and SPSS statistical analysis software was used to carry out bivariate correlation analysis and multivariate stepwise analysis of the test results, combined with the slurry performance index test regression equation and using MATLAB software optimization processing, slurry optimal mix ratio and verify, the research results show that: orthogonal test screening value, software calculation value, test value is not different. Conclusion: The results show that bentonite and CMC have significant influence on slurry indexes, while Na2CO3 and PHP can adjust slurry performance to meet the slurry use standard; the optimal mix ratio is 148 g bentonite, Na2CO3 5.2 g, CMC 3.5 g, PHP 0.05 g; the slurry ratio test analysis and treatment, and the optimization mix ratio is feasible and reasonable, class I pile proportion more than 98% to meet the actual engineering requirements.
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McNulty, Keith. "Proportional Odds Logistic Regression for Ordered Category Outcomes". W Handbook of Regression Modeling in People Analytics, 143–62. Boca Raton: Chapman and Hall/CRC, 2021. http://dx.doi.org/10.1201/9781003194156-7.
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Center, Julian L., Kevin H. Knuth, Ariel Caticha, Julian L. Center, Adom Giffin i Carlos C. Rodríguez. "Regression for Proportion Data". W BAYESIAN INFERENCE AND MAXIMUM ENTROPY METHODS IN SCIENCE AND ENGINEERING. AIP, 2007. http://dx.doi.org/10.1063/1.2821266.
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Zhang, Bin, i Shoucheng Yuan. "Analysis of Affecting Factors of Proportion of Tertiary Industry Based on Ridge Regression". W 2018 2nd International Conference on Management, Education and Social Science (ICMESS 2018). Paris, France: Atlantis Press, 2018. http://dx.doi.org/10.2991/icmess-18.2018.66.
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Ojha, Varun Kumar, Paramartha Dutta, Hiranmay Saha i Sugato Ghosh. "Linear regression based statistical approach for detecting proportion of component gases in manhole gas mixture". W 2012 1st International Symposium on Physics and Technology of Sensors (ISPTS). IEEE, 2012. http://dx.doi.org/10.1109/ispts.2012.6260865.
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Tengiz, Yusuf Ziya, i Zehra Meliha Tengiz. "A Study on Beef Price in Turkey". W International Conference on Eurasian Economies. Eurasian Economists Association, 2018. http://dx.doi.org/10.36880/c10.02213.
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Beef prices in Turkey is increased for long time. That outcome is caused to find out the reasons which are variables related to beef prices. The target of this study is to clarify relationship of beef price and its independent variables with a regression model. Data analyzed with SPSS 23.0. Based on the model’s equation, the independent variables which are average world beef unit price (USD), per capita beef consumption in Turkey (kg), government livestock incentives (TRY), consumer price index on beef (%), exchange rate (USD/TRY), real effective exchange rate (%) and gross domestic national product (%) are found as direct proportion with beef prices. On the other hand, poultry meat as an alternative to beef has inverse proportion with the prices.
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Suhendra, Euphrasia Susy, i Dini Tri Wardani. "The Influence of Corporate Governance Mechanism to Earnings Management on Indonesia and China Industrial Banking". W International Conference on Eurasian Economies. Eurasian Economists Association, 2013. http://dx.doi.org/10.36880/c04.00597.
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The goal of this research is to evaluate the influence of managerial ownership structure, independent board of commissioners proportion, independent commissioner size, and audit committee size on earnings management in banking industry in China and Indonesia. The data used is secondary data with discretionary accrual as earnings management proxy. Data is processed and analyzed by independent samples t-test and multiple linear regression The results of this research show that there is a difference between earnings management, managerial ownership structure, proportion independent board of commissioners, board of commissioners size in banking industry in Indonesia and China, however there is no difference between Audit Committee size. The variable of managerial ownership structure in Indonesian’s banking industry is negatively significant influence on earnings management, whereas in China has no influence. The variable of independent board of commissioners proportion in banking industry in Indonesia has no influence on earnings management, while negatively significant influence on China’s. The variable of Board of Commissioners size in Indonesia banking industry positively significant influence on earnings management, while negatively significant influence in China. Then, the variable of Audit Committee size in Indonesia banking industry negatively significant influence on earnings management, whereas positively significant influence in China.
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Plume, Lauris, i Imants Plume. "Analysis of factors influencing energy efficiency of biogas plants". W 22nd International Scientific Conference Engineering for Rural Development. Latvia University of Life Sciences and Technologies, Faculty of Engineering, 2023. http://dx.doi.org/10.22616/erdev.2023.22.tf150.
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The number of biogas plants in Latvia has decreased by 9 plants, from 56 in 2017 to 47 in 2022. One of the reasons for this decrease in the number of biogas plants is low energy efficiency. The energy efficiency factor is influenced by different factors. Factors influencing the operation of the 49 biogas plants in 2020 were assessed, including the factor Installed electric power that is not changeable by the plant operator. Other factors constitute a group of factors that can be compensated in daily operation like a proportion of input biomass. The parameters of all factors were analyzed using statistical methods. Results of analyses show that there is no single factor having the effect on the capacity factor with statistically acceptable reliability. However, correlation analyses and the obtained linear regression revealed two most significant factors, i.e. the proportion of manure (MA) and proportion of silage (SIL) in feedstock whose combination gives statistically significant linear equation for assessment of changes in the capacity factor (CF) MAof biogas plant. This two-factor model can be used to evaluate the capacity factor of a biogas plant with a combined input of manure and silage in Latvia.
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Okewole, Dorcas Modupe, i Olusanya Elisa Olubusoye. "Assessment Question Type in a Statistics Course for Non Majors: Analysis of Students’ Preference". W IASE 2021 Satellite Conference: Statistics Education in the Era of Data Science. International Association for Statistical Education, 2022. http://dx.doi.org/10.52041/iase.yqqbv.
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This study involves the analysis of students’ preference on the Assessment Question Type (AQT) in an applied statistics course for non majors. Developing interest in a statistics course may be greatly influenced by performance in statistics courses taken earlier or expectations on the one being considered. It is important that assessment of the students’ performance in the course be through a valid evaluation tool which includes appropriate question type. Students’ AQT preference information was obtained using an instrument designed for the purpose and was shown to vary mostly between multiple choice and essay questions. Proportion of scores from multiple choice questions in the final examination was modeled with beta regression. Students’ level of understanding of the course (as judged by the total score in the examination) was shown to influence proportion of marks from the two AQT employed. Implications of the results were discussed.
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Torres, Kevin Michael, Noura Al Madani i Rodrigo Rafael Gutierrez. "Significance in the Integration of Facies Analysis, Stable Isotopes and Diagenetical Results for the High-Resolution Sequence Stratigraphy Characterization in the Shallow Platform of Shuaiba Formation, Lower Cretaceous, Abu Dhabi Onshore, UAE". W Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/207828-ms.
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Abstract The study presents the sequence stratigraphy of the carbonate platform focused in lower part of Shuaiba Formation, as well as the organization of the arrangement formed by the cyclical sedimentological evolution at high-resolution scale, through the facies analysis, diagenetical imprints and finally, significance of stable carbonate isotope results in the building up of carbonate platform in southeast Abu Dhabi. Interpreted stratigraphic surfaces from integration of depositional facies reviewed in all available cored data within studied area and stable carbon isotope results allowed that four small-scale regression-transgression depositional cycles can be discriminated which are stacked into a medium-scale sequence, that may record a 600 kyr Milankovitch signal. The small-scale sequences were correlated within the studied area using both conventional well logs and stable isotope records. Transgression hemicycles represent the increasing of accommodation space and can be identified in direct evidence, such as 25-40 ft. thickness of lithocodium/bacinella floatstones and skeletal peloidal packstones facies, association of facies interpreted within upper slope sub-environment. Likewise, in δ13C profiles, the rise/fall turnarounds of small-scale sequences are marked by negative δ13C peaks and associated with characteristics patterns: (1) proportion decrease of shallower sub-environments facies is interpreted as an rising relative sea-level and (2) decreasing δ13C trends interpreted to be related to decreasing nutrient supply. The medium/big pores of floatstones poorly connected in packstone matrix are expressed in the medium/high porosity with low permeabilities. In contrast, regressive hemicycles represent the reduction in accommodation space and can be characterized in direct evidence, such as the growing up of persistent 10-20 ft. thickness with thousands of meters of correlation of stromatoporoids and rudist facies, association of facies interpreted within shelf-margin complex sub-environment. In addition, the fall/rise turnarounds are marked by positive δ13C peaks, associated with the stromatoporoids/rudists mounds with characteristic patterns: (1) proportion increase of shallower sub-environments facies is interpreted as falling relative sea-level and increase in proximity and (2) increasing δ13C values interpreted to reflect increasing nutrient supply. Unusually very high permeability is attributed to the present of fractures and dissolution events that is enhanced where proportion of stromatoporoids facies are more pronounced. The described characterization resulted in the identification of genetic cycles that reproduce the sedimentological evolution, which are presented in small-scale sequences. In addition, the δ13C values enabled to understand the internal organization and the development of the carbonate building up in the Shuaiba shallow platform evolution. This study provides update and understanding on sedimentary facies, depositional pattern, and expands on previous published works, using new approach from semi-regional to local scales. Finally, results help to understand the laterally extensive water break-through thin intervals, which are directly related to the regressive hemicycles described previously.
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Dousseau, Gabriella Corrêa, Heitor Nunes de Oliveira Sento-Sé Neto, Luisa Pacheco Avezum, Mariana Floriano Luiza Piva, Isabel de Oliveira Santos, José Lopes de Vasconcelos Júnior, Henrique Alves Bezerra i Maria Sheila Guimarães Rocha. "Elderly’s thrombolysis in the real-world setting: a cohort study". W XIV Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2023. http://dx.doi.org/10.5327/1516-3180.141s1.432.
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Introduction: The higher prevalence of stroke in the elderly population is increasingly recognized, but safety and efficacy of thrombolysis in this population are still debatable in clinical practice. Methods: This is a retrospective cohort study of stroke patients admitted in a health center in Brazil. We investigated the effectiveness of thrombolysis in stroke patients aged above 80y. The primary outcome was Rankin at discharge and the secondary outcome was lethality. Results: We studied a cohort of 185 stroke patients aged above 80. Mean age was 84.9 (standard deviation [SD] 4.1). The majority was female (121–65.4%). Mean initial National Institute of Health Stroke Scale (NIHSS) was 12.2 (SD 6.7). Most patients had arterial hypertension (83.2%) with equal proportion between sexes. Thrombolysis was performed in 20.8%. The proportion of risk factors was the same for those who received or not thrombolytic therapy. Age, Aspects score, and comorbidity index were similar for the groups, as was the proportion of female/male. The rate of in-hospital infection was insignificantly higher in the non-thrombolytic group (34.9% for non-thrombolytic group and 25% for the thrombolytic one; P = 0.285). NIHSS was significantly higher for the thrombolytic group (14.6 versus 10.9 points – P = 0.0007). The rate of case-fatality was 30.1% for the non-thrombolytic group and 19.3% for those treated with thrombolysis. A multivariate logistic regression analysis disclosed in-hospital infection as the main predictor of lethality (odds ratio [OR] 3.1; CI 1.33–7.15; P < 0.0001) for both groups. Predictors of a good outcome at discharge (Rankin score ≤ 2) included a lower initial NIHSS score and the treatment with thrombolysis (adjusted OR 5.3; CI 1.79–15.80). Conclusion: Thrombolysis in stroke patients aged 80 years was safe and effective, disclosing the strongest predictor of good short-term outcome.
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Gutium, Mircea. "Evolution of Consumption Expenditures of Population of the Republic of Moldova". W International Conference Innovative Business Management & Global Entrepreneurship. LUMEN Publishing, 2020. http://dx.doi.org/10.18662/lumproc/ibmage2020/23.
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Consumption expenditures is one of the key indicators that reflects the purchasing power of the population. Purchasing power in turn shows the level of social welfare. The population with a stable evolution of consumer spending is at least able to maintain its level of consumption with inflation. In addition, if consumer spending rises in proportion to the level of inflation, there is an increase in welfare and living standards. High level of consumption has positive influence on business. greater aggregate demand will generate more profits, boost company development, and foster job creation. In this study, the affirmation was verified that the consumer price index is one of the factors that influence the standard of living, but not primarily. The following scientific methods were used to approve or reject the statement: scientific abstraction, analysis and synthesis, graphical and tabular method, comparative analysis method, correlation and regression analysis. In this study there was made comparison of consumption evolution and its structure in the Republic of Moldova and in the European Union to identify the difference in welfare. The linear regression model between the consumer price index and growth rate of household expenditures was elaborated.
Raporty organizacyjne na temat "Regression of Proportion"
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Koenker, Roger, i Naveen Narisetty. Censored quantile regression survival models with a cure proportion. The IFS, październik 2019. http://dx.doi.org/10.1920/wp.cem.2019.5619.
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Puttanapong, Nattapong, Arturo M. Martinez Jr, Mildred Addawe, Joseph Bulan, Ron Lester Durante i Marymell Martillan. Predicting Poverty Using Geospatial Data in Thailand. Asian Development Bank, grudzień 2020. http://dx.doi.org/10.22617/wps200434-2.
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This study examines an alternative approach in estimating poverty by investigating whether readily available geospatial data can accurately predict the spatial distribution of poverty in Thailand. It also compares the predictive performance of various econometric and machine learning methods such as generalized least squares, neural network, random forest, and support vector regression. Results suggest that intensity of night lights and other variables that approximate population density are highly associated with the proportion of population living in poverty. The random forest technique yielded the highest level of prediction accuracy among the methods considered, perhaps due to its capability to fit complex association structures even with small and medium-sized datasets.
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Tangka, Florence K. L., Sujha Subramanian, Madeleine Jones, Patrick Edwards, Sonja Hoover, Tim Flanigan, Jenya Kaganova i in. Young Breast Cancer Survivors: Employment Experience and Financial Well-Being. RTI Press, lipiec 2020. http://dx.doi.org/10.3768/rtipress.2020.rr.0041.2007.
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The economic burden of breast cancer for women under 50 in the United States remains largely unexplored, in part because young women make up a small proportion of breast cancer cases overall. To address this knowledge gap, we conducted a web-based survey to compare data from breast cancer survivors 18–39 years of age at first diagnosis and 40–49 years of age at first diagnosis. We administered a survey to a national convenience sample of 416 women who were 18–49 years of age at the time of their breast cancer diagnosis. We analyzed factors associated with financial decline using multivariate regression. Survivors 18–39 years of age at first diagnosis were more likely to report Stage II–IV breast cancer (P<0.01). They also quit their jobs more often (14.6%) than older survivors (4.4%; P<0.01) and faced more job performance issues (55.7% and 42.8%, respectively; P=0.02). For respondents in both groups, financial decline was more likely if the survivor had at least one comorbid condition (odds ratios: 2.36–3.21) or was diagnosed at Stage II–IV breast cancer (odds ratios: 2.04–3.51).
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Shivakumar, Pranavkumar, Kanika Gupta, Antonio Bobet, Boonam Shin i Peter J. Becker. Estimating Strength from Stiffness for Chemically Treated Soils. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317383.
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The central theme of this study is to identify strength-stiffness correlations for chemically treated subgrade soils in Indiana. This was done by conducting Unconfined Compression (UC) Tests and Resilient Modulus Tests for soils collected at three different sites—US-31, SR-37, and I-65. At each site, soil samples were obtained from 11 locations at 30 ft spacing. The soils were treated in the laboratory with cement, using the same proportions used for construction, and cured for 7 and 28 days before testing. Results from the UC tests were compared with the resilient modulus results that were available. No direct correlation was found between resilient modulus and UCS parameters for the soils investigated in this study. A brief statistical analysis of the results was conducted, and a simple linear regression model involving the soil characteristics (plasticity index, optimum moisture content and maximum dry density) along with UCS and resilient modulus parameters was proposed.
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Brosh, Arieh, David Robertshaw, Yoav Aharoni, Zvi Holzer, Mario Gutman i Amichai Arieli. Estimation of Energy Expenditure of Free Living and Growing Domesticated Ruminants by Heart Rate Measurement. United States Department of Agriculture, kwiecień 2002. http://dx.doi.org/10.32747/2002.7580685.bard.
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Research objectives were: 1) To study the effect of diet energy density, level of exercise, thermal conditions and reproductive state on cardiovascular function as it relates to oxygen (O2) mobilization. 2) To validate the use of heart rate (HR) to predict energy expenditure (EE) of ruminants, by measuring and calculating the energy balance components at different productive and reproductive states. 3) To validate the use of HR to identify changes in the metabolizable energy (ME) and ME intake (MEI) of grazing ruminants. Background: The development of an effective method for the measurement of EE is essential for understanding the management of both grazing and confined feedlot animals. The use of HR as a method of estimating EE in free-ranging large ruminants has been limited by the availability of suitable field monitoring equipment and by the absence of empirical understanding of the relationship between cardiac function and metabolic rate. Recent developments in microelectronics provide a good opportunity to use small HR devices to monitor free-range animals. The estimation of O2 uptake (VO2) of animals from their HR has to be based upon a consistent relationship between HR and VO2. The question as to whether, or to what extent, feeding level, environmental conditions and reproductive state affect such a relationship is still unanswered. Studies on the basic physiology of O2 mobilization (in USA) and field and feedlot-based investigations (in Israel) covered a , variety of conditions in order to investigate the possibilities of using HR to estimate EE. In USA the physiological studies conducted using animals with implanted flow probes, show that: I) although stroke volume decreases during intense exercise, VO2 per one heart beat per kgBW0.75 (O2 Pulse, O2P) actually increases and measurement of EE by HR and constant O2P may underestimate VO2unless the slope of the regression relating to heart rate and VO2 is also determined, 2) alterations in VO2 associated with the level of feeding and the effects of feeding itself have no effect on O2P, 3) both pregnancy and lactation may increase blood volume, especially lactation; but they have no effect on O2P, 4) ambient temperature in the range of 15 to 25°C in the resting animal has no effect on O2P, and 5) severe heat stress, induced by exercise, elevates body temperature to a sufficient extent that 14% of cardiac output may be required to dissipate the heat generated by exercise rather than for O2 transport. However, this is an unusual situation and its affect on EE estimation in a freely grazing animal, especially when heart rate is monitored over several days, is minor. In Israel three experiments were carried out in the hot summer to define changes in O2P attributable to changes in the time of day or In the heat load. The animals used were lambs and young calves in the growing phase and highly yielding dairy cows. In the growing animals the time of day, or the heat load, affected HR and VO2, but had no effect on O2P. On the other hand, the O2P measured in lactating cows was affected by the heat load; this is similar to the finding in the USA study of sheep. Energy balance trials were conducted to compare MEI recovery by the retained energy (RE) and by EE as measured by HR and O2P. The trial hypothesis was that if HR reliably estimated EE, the MEI proportion to (EE+RE) would not be significantly different from 1.0. Beef cows along a year of their reproductive cycle and growing lambs were used. The MEI recoveries of both trials were not significantly different from 1.0, 1.062+0.026 and 0.957+0.024 respectively. The cows' reproductive state did not affect the O2P, which is similar to the finding in the USA study. Pasture ME content and animal variables such as HR, VO2, O2P and EE of cows on grazing and in confinement were measured throughout three years under twenty-nine combinations of herbage quality and cows' reproductive state. In twelve grazing states, individual faecal output (FO) was measured and MEI was calculated. Regression analyses of the EE and RE dependent on MEI were highly significant (P<0.001). The predicted values of EE at zero intake (78 kcal/kgBW0.75), were similar to those estimated by NRC (1984). The EE at maintenance condition of the grazing cows (EE=MEI, 125 kcal/kgBW0.75) which are in the range of 96.1 to 125.5 as presented by NRC (1996 pp 6-7) for beef cows. Average daily HR and EE were significantly increased by lactation, P<0.001 and P<0.02 respectively. Grazing ME significantly increased HR and EE, P<0.001 and P<0.00l respectively. In contradiction to the finding in confined ewes and cows, the O2P of the grazing cows was significantly affected by the combined treatments (P<0.00l ); this effect was significantly related to the diet ME (P<0.00l ) and consequently to the MEI (P<0.03). Grazing significantly increased O2P compared to confinement. So, when EE of grazing animals during a certain season of the year is estimated using the HR method, the O2P must be re measured whenever grazing ME changes. A high correlation (R2>0.96) of group average EE and of HR dependency on MEI was also found in confined cows, which were fed six different diets and in growing lambs on three diets. In conclusion, the studies conducted in USA and in Israel investigated in depth the physiological mechanisms of cardiovascular and O2 mobilization, and went on to investigate a wide variety of ruminant species, ages, reproductive states, diets ME, time of intake and time of day, and compared these variables under grazing and confinement conditions. From these combined studies we can conclude that EE can be determined from HR measurements during several days, multiplied by O2P measured over a short period of time (10-15 min). The study showed that RE could be determined during the growing phase without slaughtering. In the near future the development microelectronic devices will enable wide use of the HR method to determine EE and energy balance. It will open new scopes of physiological and agricultural research with minimizes strain on animals. The method also has a high potential as a tool for herd management.
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Edeh, Henry C. Assessing the Equity and Redistributive Effects of Taxation Reforms in Nigeria. Institute of Development Studies (IDS), listopad 2021. http://dx.doi.org/10.19088/ictd.2021.020.
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Achieving the Sustainable Development Goals (SDGs) of poverty and inequality reduction through redistribution have indeed become critical concerns in many low- and middle-income countries, including Nigeria. Although redistribution results from the effect of tax revenue collections, micro household-level empirical analyses of the distributional effect of personal income tax (PIT) and value added tax (VAT) reforms in Nigeria have been scarcely carried out. This study for the first time quantitatively assessed both the equity and redistributive effects of PIT and VAT across different reform scenarios in Nigeria. Data used in this study was mainly drawn from the most recent large scale nationally representative Nigeria Living Standard Survey, conducted in 2018/2019. The Kakwani Index was used to calculate and compare the progressivity of PIT and VAT reforms. A simple static micro-simulation model was employed in assessing the redistributive effect of PIT and VAT reforms in the country. After informality has been accounted for, the PIT was found to be progressive in the pre- 2011 tax scheme, but turned regressive in the post-2011 tax scheme. It was also discovered that the newly introduced lump sum relief allowance in the post-2011 PIT scheme accrues more to the high-income than to the low-income taxpayers – confirming the regressivity of the current PIT scheme. However, the study further shows (through counterfactual simulations) that excluding the relatively high-income taxpayers from sharing in the variable part of the lump sum relief allowance makes PIT progressive in the post-2011 scheme. The VAT was uncovered to be regressive both in the pre-2020 scheme, and in the current VAT reform scheme. Further, after putting informality into consideration, the PIT was found to marginally reduce inequality but increase poverty in the pre-2011 scheme. The post-2011 PIT scheme reduced inequality and increased poverty, but by a smaller proportion – confirming a limited redistribution mainly resulting from the concentration of the lump sum relief allowance at the top of the distribution. However, if the variable part of the lump sum relief allowance is provided for ‘only’ the low-income taxpayers below a predefined income threshold, the post-2011 PIT scheme becomes largely redistributive. VAT was uncovered to marginally increase inequality and poverty in the pre-2020 scheme. Though the current VAT scheme slightly increased inequality, it considerably increased poverty in the country. It is therefore suggested that a better tax reform, with well-regulated relief allowance and differentiated VAT rates, will help to enhance the equity and redistribution capacity of the Nigeria tax system.
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Börjesson, Patrik, Maria Eggertsen, Lachlan Fetterplace, Ann-Britt Florin, Ronny Fredriksson, Susanna Fredriksson, Patrik Kraufvelin i in. Long-term effects of no-take zones in Swedish waters. Redaktorzy Ulf Bergström, Charlotte Berkström i Mattias Sköld. Department of Aquatic Resources, Swedish University of Agricultural Sciences, 2023. http://dx.doi.org/10.54612/a.10da2mgf51.
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Marine protected areas (MPAs) are increasingly established worldwide to protect and restore degraded ecosystems. However, the level of protection varies among MPAs and has been found to affect the outcome of the closure. In no-take zones (NTZs), no fishing or extraction of marine organisms is allowed. The EU Commission recently committed to protect 30% of European waters by 2030 through the updated Biodiversity Strategy. Importantly, one third of these 30% should be of strict protection. Exactly what is meant by strict protection is not entirely clear, but fishing would likely have to be fully or largely prohibited in these areas. This new target for strictly protected areas highlights the need to evaluate the ecological effects of NTZs, particularly in regions like northern Europe where such evaluations are scarce. The Swedish NTZs made up approximately two thirds of the total areal extent of NTZs in Europe a decade ago. Given that these areas have been closed for at least 10 years and can provide insights into long-term effects of NTZs on fish and ecosystems, they are of broad interest in light of the new 10% strict protection by 2030 commitment by EU member states. In total, eight NTZs in Swedish coastal and offshore waters were evaluated in the current report, with respect to primarily the responses of focal species for the conservation measure, but in some of the areas also ecosystem responses. Five of the NTZs were established in 2009-2011, as part of a government commission, while the other three had been established earlier. The results of the evaluations are presented in a synthesis and also in separate, more detailed chapters for each of the eight NTZs. Overall, the results suggest that NTZs can increase abundances and biomasses of fish and decapod crustaceans, given that the closed areas are strategically placed and of an appropriate size in relation to the life cycle of the focal species. A meta-regression of the effects on focal species of the NTZs showed that CPUE was on average 2.6 times higher after three years of protection, and 3.8 times higher than in the fished reference areas after six years of protection. The proportion of old and large individuals increased in most NTZs, and thereby also the reproductive potential of populations. The increase in abundance of large predatory fish also likely contributed to restoring ecosystem functions, such as top-down control. These effects appeared after a 5-year period and in many cases remained and continued to increase in the longer term (>10 years). In the two areas where cod was the focal species of the NTZs, positive responses were weak, likely as an effect of long-term past, and in the Kattegat still present, recruitment overfishing. In the Baltic Sea, predation by grey seal and cormorant was in some cases so high that it likely counteracted the positive effects of removing fisheries and led to stock declines in the NTZs. In most cases, the introduction of the NTZs has likely decreased the total fishing effort rather than displacing it to adjacent areas. In the Kattegat NTZ, however, the purpose was explicitly to displace an unselective coastal mixed bottom-trawl fishery targeting Norway lobster and flatfish to areas where the bycatches of mature cod were smaller. In two areas that were reopened to fishing after 5 years, the positive effects of the NTZs on fish stocks eroded quickly to pre-closure levels despite that the areas remained closed during the spawning period, highlighting that permanent closures may be necessary to maintain positive effects. We conclude from the Swedish case studies that NTZs may well function as a complement to other fisheries management measures, such as catch, effort and gear regulations. The experiences from the current evaluation show that NTZs can be an important tool for fisheries management especially for local coastal fish populations and areas with mixed fisheries, as well as in cases where there is a need to counteract adverse ecosystem effects of fishing. NTZs are also needed as reference for marine environmental management, and for understanding the effects of fishing on fish populations and other ecosystem components in relation to other pressures. MPAs where the protection of both fish and their habitats is combined may be an important instrument for ecosystembased management, where the recovery of large predatory fish may lead to a restoration of important ecosystem functions and contribute to improving decayed habitats. With the new Biodiversity Strategy, EUs level of ambition for marine conservation increases significantly, with the goal of 30% of coastal and marine waters protected by 2030, and, importantly, one third of these areas being strictly protected. From a conservation perspective, rare, sensitive and/or charismatic species or habitats are often in focus when designating MPAs, and displacement of fisheries is then considered an unwanted side effect. However, if the establishment of strictly protected areas also aims to rebuild fish stocks, these MPAs should be placed in heavily fished areas and designed to protect depleted populations by accounting for their home ranges to generate positive outcomes. Thus, extensive displacement of fisheries is required to reach benefits for depleted populations, and need to be accounted for e.g. by specific regulations outside the strictly protected areas. These new extensive EU goals for MPA establishment pose a challenge for management, but at the same time offer an opportunity to bridge the current gap between conservation and fisheries management.
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Goetsch, Arthur L., Yoav Aharoni, Arieh Brosh, Ryszard (Richard) Puchala, Terry A. Gipson, Zalman Henkin, Eugene D. Ungar i Amit Dolev. Energy Expenditure for Activity in Free Ranging Ruminants: A Nutritional Frontier. United States Department of Agriculture, czerwiec 2009. http://dx.doi.org/10.32747/2009.7696529.bard.
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Heat production (HP) or energy expenditure for activity (EEa) is of fundamental nutritional importance for livestock because it determines the proportion of ingested nutrients available for productive functions. Previous estimates of EEa are unreliable and vary widely with different indirect methodologies. This leads to erroneous nutritional strategies, especially when intake on pasture does not meet nutritional requirements and supplementation is necessary for acceptable production. Therefore, the objective of this project was to measure EEa in different classes of livestock (beef cattle and goats) over a wide range of ecological and management conditions to develop and evaluate simple means of prediction. In the first study in Israel, small frame (SF) and large frame (LF) cows (268 and 581 kg) were monitored during spring, summer, and autumn. Feed intake by SF cows per unit of metabolic weight was greater (P < 0.001) than that by LF cows in both spring and summer and their apparent selection of higher quality herbage in spring was greater (P < 0.10) than that of LF cows. SF cows grazed more hours per day and walked longer distances than the LF cows during all seasons. The coefficient of specific costs of activities (kJ•kg BW-0.75•d-1) and of locomotion (J•kg BW-0.75•m-1) were smaller for the SF cows. In the second study, cows were monitored in March, May, and September when they grazed relatively large plots, 135 and 78 ha. Energy cost coefficients of standing, grazing, and horizontal locomotion derived were similar to those of the previous study based on data from smaller plots. However, the energy costs of walking idle and of vertical locomotion were greater than those found by Brosh et al. (2006) but similar to those found by Aharoni et al. (2009). In the third study, cows were monitored in February and May in a 78-ha plot with an average slope of 15.5°, whereas average plot slopes of the former studies ranged between 4.3 and 6.9°. Energy cost coefficients of standing, grazing, and walking idle were greater than those calculated in the previous studies. However, the estimated energy costs of locomotion were lower in the steeper plot. A comparison on a similar HP basis, i.e., similar metabolizable energy (ME) intake, shows that the daily energy spent on activities in relation to daily HP increased by 27% as the average plot slope increased from 5.8 and 6.02 to 15.5°. In the fourth study, cows grazing in a woodland habitat were monitored as in previous studies in December, March, and July. Data analysis is in progress. In the first US experiment, Boer and Spanish does with two kids were used in an experiment beginning in late spring at an average of 24 days after kidding. Two does of each breed resided in eight 0.5-ha grass/forb pastures. Periods of 56, 60, 63, 64, and 73 days in length corresponded to mid-lactation, early post-weaning, the late dry period, early gestation, and mid-gestation. EEa expressed as a percentage of the ME requirement for maintenance plus activity in confinement (EEa%) was not influenced by stocking rate, breed, or period, averaging 49%. Behavioral activities (e.g., time spent grazing, walking, and idle, distance traveled) were not highly related to EEa%, although no-intercept regressions against time spent grazing/eating and grazing/eating plus walking indicated an increase in EEa% of 5.8 and 5.1%/h, respectively. In the second study, animal types were yearling Angora doeling goats, yearling Boer wether goats, yearling Spanish wether goats, and Rambouilletwether sheep slightly more than 2 yr of age. Two animals of each type were randomly allocated to one of four pastures 9.3, 12.3, 4.6, and 1.2 ha in area. The experiment was conducted in the summer with three periods, 30, 26, and 26 days in length. EEa% was affected by an interaction between animal type and period (Angora: 16, 17, and 15; Boer: 60, 67, and 34; Spanish: 46, 62, and 42; sheep: 22, 12, and 22% in periods 1, 2, and 3, respectively (SE = 6.1)). EEa% of goats was predicted with moderate accuracy (R2 = 0.40-0.41) and without bias from estimates of 5.8 and 5.1%/h spent grazing/eating and grazing/eating plus walking, respectively, determined in the first experiment; however, these methods were not suitable for sheep. These methods of prediction are simpler and more accurate than currently recommended for goats by the National Research Council.