Top PDF Analysis of Life Histories: A State Space Approach

Analysis of Life Histories: A State Space Approach

Analysis of Life Histories: A State Space Approach

few other programs in LIFEHIST such as those programs for constructing Single Decrement, Multiple Decrement Life Tables as well as for doing a Cox Proportional Hazards Analysis (for time-invariant and time-varying covariates). I say ‘for Canadian researchers’ because most Canadian survey data come with sample weights attached to each individual and these weights have to be used for proper analysis. Unfortunately, most statistical packages do not allow using fractional weights, and using discrete weights in whatever modified form in these packages makes the standard errors meaningless. There is a way of correcting the standard errors produced by these packages (see Zhao et al., 1995 for details) but most researchers may not be able to follow such procedures. In these extra programs included in LIFEHIST, I have considered possible improvements to the existing procedures. For example, in constructing single decrement life tables, a common procedure in all the packages is to assume linearity or uniformity of events in a specific time interval. LIFEHIST includes in the output Chiang’s coefficients for average lifetime that can show whether the assumption is valid or not for each interval, and uses these coefficients rather than the linearity assumption in constructing the life tables. Thus, the LIFEHIST output may differ from the outputs produced by other packages. Similarly, in the Cox proportional hazards model output, users will find some useful information on the rank of the timing vector and on ties. Few researchers nowadays have time to worry about all these finer details on the assumptions on which analytical techniques are based, without being aware that their inferences are not justified when these assumptions are not met. Working with longitudinal data calls for a serious attention to many such assumptions with which we do our research.
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STATE-SPACE APPROACH FOR THE ANALYSIS OF SOIL WATER CONTENT AND TEMPERATURE IN A SUGARCANE CROP

STATE-SPACE APPROACH FOR THE ANALYSIS OF SOIL WATER CONTENT AND TEMPERATURE IN A SUGARCANE CROP

latosol, called “terra roxa estruturada” (Rhodic Kandindox) (Figure 1). The crop was planted in October 1997, harvested in October 1998, and after this the soil temperature and moisture study began, using the first ratoon crop. Three management treatments were compared: i. mulching with trash (cane tips and straw from the last harvest, T 1 and T 2 ); ii. bare soil between rows (T 3 ); and iii. soil surface with the residues left by the traditional practice of straw burning before harvest (T 4 ). The treatments T 1 and T 2 are similar in respect to the mulching with trash, and therefore replicates in terms of this soil temperature study, being different only in terms of 15 N label which was used in an additional
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Reducing the impact of state space explosion in Stochastic Automata Networks

Reducing the impact of state space explosion in Stochastic Automata Networks

The discrete event simulation aims to reproduce the system evolution step by step studying a par- ticular realization of a stochastic model. As discussed on Section 4.1 the advantage is that simulation is a generic approach that can be applied to every model described as a set of events and associ- ated transition functions. The main disadvantages are related to the simulation computational cost (justifiable only if there is no analytical solution available) and the statistical validation since tradi- tional approaches does not guarantee exact samples and it is difficult to determine values such as the burning time period, the starting state and the quantity of samples a priori. The backward coupling simulation provides a way to overcome the forward simulation drawbacks (the choose of an initial state, not necessary anymore since we use all states starting parallel trajectories, and the transient period determination, eliminated since there are a finite number of steps in the past to collect an exact sample). The simulation results can be presented with confidence intervals allowing the verification if the quantity of samples generated is sufficient for the model statistical analysis.
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Simulation of an Economic Policy on Second Life Using a Conjunctural Analysis Approach

Simulation of an Economic Policy on Second Life Using a Conjunctural Analysis Approach

The State rarely interferes, it is the kingdom of: Laissez-faire. The Domestic revenues should be increased in order to select dynamic residents who can stimulate investment to contribute to GDP. Indeed, internal revenue = subscription fees, by increasing this tax, we could select residents who are really eager to have a return on investment for the money spent for the subscription Decrease of custom taxes in order to warm up trades. Donations are increased to 3% of GDP in the year T +1, depending on fundings from "Diplo Foundation, a research institute whose research purpose focuses on issues related to ICT. Increase in other revenues due to progress in the building sector. Changing the structure of expenditures. Regarding capital expenditures, the state of technology being the best to date, it would be better if the State invest in the field of electronic security to enforce the confidence of residents and multinationals and encourage them to invest. It will be the matter of ensuring quality of services offered by residents, to care about the legality of their activities etc. The wages and materials are increased to encourage officials and other specialists are employed. Capital expenditures increase by 25%, while expenses increase by 11%. Capital expenditures increase more than current spending. As for interest on public debt, its overall variation is negligible, but the payment of interest on the debt inside the country is growing while the payment of interest for external debt does not vary. Capital expenditures increase by 25%, while expenses increase by 11%. Capital expenditures increase more than current spending. For the deficit financing, the interior financing diminish to alleviate the internal pressure over domestic saving and avoid crowding - out "effect.
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Estimating Brazilian monthly GDP: a state-space approach

Estimating Brazilian monthly GDP: a state-space approach

Our …rst step is to get as many series as possible that satisfy the …rst condition, later checking which of them satisfy the second condition. As a starting point, we considered the …rst two series that represent monthly economic activity – Industrial Production, labelled IP, and Sales, labelled Sales. For these variables we have long-span data, and they are believed to have cycles that are concurrent with the latent “business cycles.” Since Stock and Watson (1999) argue that, if we were to choose one variable to best represent the state of business cycles, this variable would be the GDP, a natural empirical strategy to interpolate GDP would be to use not only the coincident series used in business-cycle analysis but also additional coincident series as well. The latter can be veri…ed by standard methods – e.g., the Bry and Boschan (1971) algorithm. In order to increase the number of coincident series, we follow Cardoso (1981), from which we have selected additional four candidate series: Energy Demand – labelled Energy, Steel Production – labelled Steel, Cement Production – labelled Cement, and Vehicle Production – labelled Vehicles.
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STATE-SPACE APPROACH TO EVALUATE THE RELATION BETWEEN SOIL PHYSICAL AND CHEMICAL PROPERTIES

STATE-SPACE APPROACH TO EVALUATE THE RELATION BETWEEN SOIL PHYSICAL AND CHEMICAL PROPERTIES

Figure 4a presents the state-space analysis applied to soil water content, soil organic matter, clay content, and aggregate stability with the open circle symbol representing the measured soil water content. The middle line represents the predicted values of soil water content using the state equation. The upper and the lower lines represent the fiducial limits which take a plus or minus two standard deviation, respectively, into consideration. It can be seen from the equation in the figure that the soil water content at location i-1 contributes with about 91 % to the estimate of the soil water content in location i, while organic matter, clay content, and aggregate stability at location i-1 contribute 7, 6, and 2.4 %, respectively. Figure 4b indicates that this state-space model under use of all four series describes the soil water content (R 2 = 0.797) better than the
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Estimating Brazilian monthly GDP: a state-space approach

Estimating Brazilian monthly GDP: a state-space approach

Our …rst step is to get as many series as possible that satisfy the …rst condition, later checking which of them satisfy the second condition. As a starting point, we considered the …rst two series that represent monthly economic activity – Industrial Production, labelled IP, and Sales, labelled Sales. For these variables we have long-span data, and they are believed to have cycles that are concurrent with the latent “business cycles.” Since Stock and Watson (1999) argue that, if we were to choose one variable to best represent the state of business cycles, this variable would be the GDP, a natural empirical strategy to interpolate GDP would be to use not only the coincident series used in business-cycle analysis but also additional coincident series as well. The latter can be veri…ed by standard methods – e.g., the Bry and Boschan (1971) algorithm. In order to increase the number of coincident series, we follow Cardoso (1981), from which we have selected additional four candidate series: Energy Demand – labelled Energy, Steel Production – labelled Steel, Cement Production – labelled Cement, and Vehicle Production – labelled Vehicles.
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Water volume reduction increases eutrophication risk in tropical semi-arid reservoirs

Water volume reduction increases eutrophication risk in tropical semi-arid reservoirs

Even though there are multiple studies in the Brazilian semi-arid region dealing with eutrophication and their associated problems in lakes and reservoirs (Freire et al., 2009; Barbosa et al., 2012; Medeiros  et  al., 2014; Costa  et  al., 2016; Brasil  et  al., 2016), few have analyzed how dramatic shifts in rainfall reduction affect key limnological variables, such us total phosphorus and chlorophyll-a. Thus, this study aims to test the hypothesis that the reduction of water volume, driven by prolonged droughts, affects the trophic state of Brazilian semi-arid reservoirs by increasing their susceptibility to eutrophication. To do so, we used a comparative analysis of ecosystems in a space-for-time substitution approach to predict the consequences of reservoirs water volume reduction on the total concentrations of phosphorus, nitrogen and chlorophyll-a, turbidity, conductivity, and Secchi depth. We compared the previous variables from two sets of reservoirs located in a Brazilian semi-arid region with contrasting levels of precipitation.
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Análise estatística multivariada de parâmetros de qualidade de leite cru refrigerado no estado de Minas Gerais

Análise estatística multivariada de parâmetros de qualidade de leite cru refrigerado no estado de Minas Gerais

Data analysis of refrigerated raw milk from 722 producers in five regions of the Minas Gerais State were used to evaluate, in a multivariate space, the associations between the variables to assess the milk quality. The following variables were considered: milk fat, protein, lactose, total solids, and solids nonfat contents, somatic cell count (SCC) and total bacterial count. The first analysis of principal components showed that from the seven principal components obtained from the correlation matrix, three had variance less than 0.7 (eigenvalue), which indicated the exclusion of three variables (those that have higher correlation with the principal components of less eigenvalue): total solids, and solids nonfat contents, and SCC. The exclusion of only two of these variables, total solids, and solids nonfat contents, resulted in higher correlation with levels of protein and fat. The third variable, SCC was not excluded because, internationally, it is one of the most important parameters to determine the quality of raw milk. Then, further analysis was performed and the associations between variables could be observed. With the implementation of each component a score was calculated for classification of producers. The cluster analysis was used to form groups according to similarity in quality of milk produced. It can be concluded that the approach of multivariate data analysis of raw milk is a good alternative as a tool to evaluate what are the most important variables to determine associations and to form group producer's according to milk quality.
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Estimating brazilian monthly GDP: a state-space approach

Estimating brazilian monthly GDP: a state-space approach

Our …rst step is to get as many series as possible that satisfy the …rst condition, later checking which of them satisfy the second condition. As a starting point, we considered the …rst two series that represent monthly economic activity – Industrial Production, labelled IP, and Sales, labelled Sales. For these variables we have long-span data, and they are believed to have cycles that are concurrent with the latent “business cycles.” Since Stock and Watson (1999) argue that, if we were to choose one variable to best represent the state of business cycles, this variable would be the GDP, a natural empirical strategy to interpolate GDP would be to use not only the coincident series used in business-cycle analysis but also additional coincident series as well. The latter can be veri…ed by standard methods – e.g., the Bry and Boschan (1971) algorithm. In order to increase the number of coincident series, we follow Cardoso (1981), from which we have selected additional four candidate series: Energy Demand – labelled Energy, Steel Production – labelled Steel, Cement Production – labelled Cement, and Vehicle Production – labelled Vehicles.
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ANÁLISE DE DADOS DE SOLO VIA MÉTODOS DE ESPAÇO DE ESTADO: REGRESSÃO COM COEFICIENTES VARIÁVEIS

ANÁLISE DE DADOS DE SOLO VIA MÉTODOS DE ESPAÇO DE ESTADO: REGRESSÃO COM COEFICIENTES VARIÁVEIS

ABSTRACT: The assessment of the relationship among soil properties (such as total nitrogen and organic carbon) taken along lines called transects is a subject of great interest in agricultural experimentation. This question has been usually approached through standard state-space methods by some authors in the soil science literature. Important limitations of the mentioned procedures used in practice are pointed out and discussed in this paper, specially those related to the model parameters, meaning and practical interpretation. In the standard state-space approach, based on an autoregressive structure, it does not present any parameters that express the variables relationship at the same point in space, but only at lagged points. Also, its model parameters (in the transition matrix) have a global meaning and not a local one, not expressing more directly the soil heterogeneity. Therefore, the objective here is to propose an alternative state-space approach, based on dynamic (space-varying parameters) regression models in order to avoid the mentioned drawbacks. Soil total nitrogen and soil organic carbon samples were collected on a Typic Haplustox. Samples were taken along a line (transect) located in the middle of two adjacent contour lines. The transect samples, totaling 97, were collected in the plow layer (0-0.20 m) at points spaced 2 meters appart. Results show the comparative advantages of the proposed method (based on an alternative state- space approach) in relation to the standard state-space analysis. Such advantages are related to a more adequate incorporation of soil heterogeneity along the spatial transect resulting in a better model fitting, and greater flexibility of the model’s building process with an easier interpretability of the local model coefficients.
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Reconstructed State Space Model for Recognition of Consonant - Vowel (Cv) Utterances Using Support Vector Machines

Reconstructed State Space Model for Recognition of Consonant - Vowel (Cv) Utterances Using Support Vector Machines

For reasons ranging from technological curiosity about the mechanisms for mechanical realization of human speech capabilities, to the desire to automate simple tasks naturally requiring human-machine interactions, research in ASR and speech synthesis by machine has attracted a great deal of attention over the past six decades . To design an intelligent machine that can recognize the spoken word by different speakers in different environments and comprehend its meaning is far from achieving the desired goal on any language. As the speech recognition technology becomes more and more sophisticated, its uses become more and more widespread. For decades, AT & T Bell Labs, USA has been at the fore front of speech recognition and natural language technology research. They have invested more than one million research hours over the past few decades in Speech and Language technology research. Recently it is reported that they have developed a core technology platform, which is a cloud – based system of services that not only identifies words but interprets meaning and context to deliver accurate result. The system is built on servers that model and compare speech to recorded voices. This system needs to get improved accuracy so as to use as a speaker independent continuous speech recognition and understanding system in English.
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Rev. LatinoAm. Enfermagem  vol.18 número1

Rev. LatinoAm. Enfermagem vol.18 número1

Because CF is a congenital disease and is most often diagnosed during childhood, many children with CF start to quantify their differences. For example, they realize, only by being in contact with their peers, that they are smaller and thinner than their peers, that they cough and become tired more easily, and thus the school environment is frequently the landmark of their experience with their chronic disease (5,8-10) .

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Modeling and Analysis of Queuing Systems in Banks A case study of Ghana Commercial Bank Ltd. Kumasi Main Branch

Modeling and Analysis of Queuing Systems in Banks A case study of Ghana Commercial Bank Ltd. Kumasi Main Branch

Abstract: Queues are common sight of many banks in Ghana. The obvious implication of customers waiting in long and winding queues could result to prolonged discomfort and economic cost to them; however increasing the service rate will require additional number of tellers which implies extra cost to management. This study therefore attempts to find the trade-off between minimizing the total economic cost (waiting cost and service cost) and the provision of a satisfactory and reasonably shortest possible time of service to customers, in order to assist management of the bank in deciding the optimal number of tellers needed. Data for this study was collected at the Ghana Commercial Bank Ltd, Kumasi Main Branch for one month through observations, interviews and by administering of questionnaire and was formulated as multi-server single line queuing model. The data was analyzed using TORA optimization Software as well as using descriptive method of analysis. The performance measures of different queuing systems were evaluated and analyzed. The results of the analysis showed using a five teller system was better than a four or a six-teller system in terms of average waiting time and thetotal economic cost, hence the study recommends that, the management should adopt a five teller model to reduce total economic costs and increase customer satisfaction.
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PERFUSION SYSTEM CONTROLLER STRATEGIES DURING AN ECMO SUPPORT

PERFUSION SYSTEM CONTROLLER STRATEGIES DURING AN ECMO SUPPORT

ECMO support has been established as a routine treatment used for the patients whose Heart or Lungs is not working properly and is most often used for Bypass procedures, and Heart transplantations. The ECMO procedure is similar to a Heart-Lung bypass used during open-Heart surgery. Extracorporeal Membrane Oxygenation can take over the function of the child's Heart and / or Lungs for a limited time until the child recovers from the initial cause of the failure [4]. Figure 1 shows a new born having respiratory failure is placed in ECMO setup in ICU. The most frequent use for ECMO has been with new born infants with lack of a fully functioning respiratory system or other birth defect,although it may also be helpful in selected cases of severe heart failure in adults and children. During CPB the functions of the Heart and Lungs are taken over by the ECMO setup there by guaranteeing a bloodless, motionless operating field. In Extra Corporeal Membrane Oxygenator the blood is circulated from the venous to the arterial side of the patient’s vascular system by a pump in the machine. Additionally an Oxygenator takes over the function of the Lungs by the addition of fresh Oxygen (O 2 ) to and the removal of Carbon
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Economic development and crime in Brazil: a multivariate and spatial analysis

Economic development and crime in Brazil: a multivariate and spatial analysis

To fill this gap in the literature, the present paper aims to characterize the spatial distribution of crime among Brazilian municipalities, specifically the presence of spatial dependence and heterogeneity, as well as the formation of significant clusters. We seek to test the hypothesis that crime suffers from spatial effects; in other words, that it is spatially concentrated in certain regions throughout the territory. In order to achieve the objective proposed, we use Exploratory Spatial Data Analysis (ESDA) as a tool to identify and measure such spatial effects. Although there are no studies that have investigated this matter considering all Brazilian municipalities, many papers that investigate crime at the local or aggregate levels have identified the spatial component as important to explain crime distribution in Brazil (ALMEIDA et al., 2005; OLIVEIRA, 2008; ALMEIDA; GUANZIROLI, 2013; PLASSA; PARRÉ, 2015; ANJOS JÚNIOR et al., 2016; SASS et al., 2016; GOMES et al., 2017).
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J. Aerosp. Technol. Manag.  vol.3 número3

J. Aerosp. Technol. Manag. vol.3 número3

One method to develop a control system for on/off actuators can be found in minimum-time problem, in optimal control theory. This method permits to calculate the optimal time to turn on and off the actuators and, consequently, to get the optimal payload trajectory in the state space. Based on this, it will be developed a modiied method that uses the initial conditions for an optimal trajectory to create or adjust a switching function. Minimum-time problem has a good performance when the parameters of a dynamic system are well known, but this performance is affected when there are parameter uncertainties. Therefore, the switching function must be created or adjusted to these uncertainties in real time. In this paper, it will be shown the performance and how to adjust the RCS control algorithm for the following parameter uncertainties: payload mass, payload inertial momentum, actuator torque level, and/or actuator response delay. This control algorithm also has the advantage that it does not require great effort in processing.
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Fractional Order Modelling Using State Space Theory

Fractional Order Modelling Using State Space Theory

Abstract - There are various fractional order systems existing. This paper deals with the modelling of fractional order systems using an old and unique model structure i.e. state space model. The fractional order process system can be mathematically modelled by state space model. Simulation results validated that the fractional order model using state space is better as compared to other models such as first order with delay.

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Sao Paulo Med. J.  vol.127 número4

Sao Paulo Med. J. vol.127 número4

It is impossible to fully comprehend the impact of adverse pregnan- cy outcomes on the subsequent pregnancy. However, some measure- ments may be able to show the efect of these outcomes on quality of life. Some of the consequences of previous pregnancy loss on the subse- quent pregnancy are relected in the results from the SF-36 domains. A study that investigated the psychometric properties of the SF-36 ques- tionnaire in relation to the index pregnancy conirmed that this tool could be used in clinical practice to measure quality of life on eight sub- scales during early pregnancy. 24
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Connection space approach to ambiguities of gauge theories

Connection space approach to ambiguities of gauge theories

This paper presents a formal property which shows up in the space of gauge poten- tials and provides (at least) a partial classification of the connections corresponding to a given curvature. We will use both the physicist’s and the mathematician’s nomenclatures interchangeably. It should perhaps be recalled that what physicists call “gauge potentials” and “field strengths” are, in the language of mathematicians, “connections” and “curva- tures” on fiber bundles. They are, respectively, 1-forms and 2-forms with values in the Lie algebra of the gauge group (the bundle “structure group”). Connections and curva- tures belong, consequently, to the adjoint representation, in which the group acts on its own Lie algebra. We will use an invariant notation, such as A = J a A a µ dx µ for a connec-
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