La modélisation spatialisée de la demande de transport de fret est classiquement fondée sur une représentation `a quatre étapes des décisions que prennent les chargeurs et les transporteurs; cette représentation distingue les décisions de volume émis et reçus, de choix de fournisseur ou destinataire, de mode de transport et enfin d’itinéraire. Mais le transport de marchandise est une opération de nature discrète : les marchandises sont transportées par blocs, ou envois. Ces envois sont absents de la représentation à quatre étapes. Ce travail a pour but d’étudier le rôle du choix de la taille d’envois dans le fonctionnement du transport de fret. Après une revue de la modélisation du transport de fret et de certains problèmes logistiques, le transport de fret est analysé et décrit de fa¸con systémique. Les agents en jeu et leurs comportements sont identifiés. La distinction entre consommation et production du transport de fret est établie, ce qui permet de clarifier le lien entre logistique et transport de fret. Ensuite, l’attention est portée sur l’observation empirique du système de transport de fret. Des propositions sont faites pour améliorer les enquêtes en bord de route menées en France auprès des poids lourds. Elles concernent principalement la productivité et les options techniques des transporteurs routiers. Une validation économétrique du modèle micro économique de taille d’envoi optimale Economic Order Quantity est effectuée au moyen de la base de données ECHO. Enfin, la modélisation microéconomique est employée pour traiter deux sujets en particulier. Premièrement, pour analyser en détail la formation des prix d’équilibre de transport de fret, en représentant les impératifs logistiques des chargeurs et la technologie des transporteurs (notamment la consolidation d’envois). Deuxièmement pour représenter en détail le lien entre la logistique des chargeurs et leur demande de transport de fret, afin, entre autre, de pouvoir modéliser l’usage simultané de deux modes de transport par un unique transporteur pour un unique flux de marchandises / Classic spatialised freight transport models are based on a four stage representation of the decisions shippers and carriers take. The decisions this representation distinguishes are: emitted and received flow rates, supplier or receiver choice, transport mode, itinerary. However, freight transport is discrete by nature: commodities are moved by bundles called shipments. Shipments are absent from the four stage representation. This study is aimed at investigating the role of the choice of shipment size in the freight transport system. After a review of recent freight transport modelling advances and of some logistic models, we proceed to a systems analysis of freight transport. Agents are identified, their behaviours and relationships are described. This allows for a clarification of the linkage between logistics and freight transport. Then, attentions is paid to the empirical observation of the freight transport system. Propositions are made to improve French roadside surveys, so as to better observe the productivity and technical choices of motor carriers. The seminal microeconomic model of optimal shipment size called Economic Order Quantity is assessed econometrically using the ECHO database. Lastly, two particular issues are addressed using microeconomic models. First, the equilibrium freight rates of a schematic road freight transport market are modelled, on the basis of an explicit representation of the logistic imperatives of shippers and of the technology of carriers (the consolidation of shipments in vehicles is accounted for). Second, the logistic imperatives of shippers are analysed in detail to explain why a shipper would use two transport modes simultaneously for a unique commodity flow

This study utilized a new database of levee failures along 685 km of the Middle and Lower Mississippi River from St. Louis, MO to Memphis, TN during the past 120 years. The goals of this investigation were to: 1) identify the relative importance of geologic and geomorphic factors that have led to levee failures through the past century along the Mississippi River and 2) measure levee crest elevations to determine if they have increased or decreased between 1998 and 2007 and if they are built to the proper design grade elevation. Logistic regression analysis was utilized to examine selected site characteristics at each levee failure location. These site characteristics (levee failure parameters) included: 1) levee underlain by previous channel fill, 2) presence/absence of borrow pit, 3) location of failure on a meander bend, 4) width of channel, 5) width of floodway, 6) constriction-over-time factor, 7) land-cover type, 8) width of vegetative buffer, 9) sinuosity of channel, 10) intensity of dredging, and 11) presence/absence of bank revetment. Each of these parameters was evaluated using geologic maps, soil survey data, Digital Elevation Models (DEMs), historic river maps, and dredging reports (Winkley, 1977; Pinter et al., 2004). Two models were created for each river reach. The first model for both reaches used a 95% significance threshold, while the second model for the MMR used a 80% significance threshold, and the second model for the LMR used a 90% significance threshold. The first model for the Middle Mississippi River (MMR) identified only the presence/absence of channel fills to predict levee failure as significant, had an R² value of 0.178, a p-value of 0.002, and a percentage accuracy of 68.6%. The second model for the MMR identified the following variables as significant: presence/absence of channel fills to predict levee failure, location of failure on a meander bend, channel width, land-cover type, and intensity of dredging. This model had an R2 value of 0.408, p-value of 0.002, and a percentage accuracy of 74.3%. The 95% model for the Lower Mississippi River (LMR) identified location of failure on a meander bend, land-cover type, constriction-over-time factor, and sinuosity of the channel as significant. This model had an R2 value of 0.326, p-value of 0.003, and a percentage accuracy of 69.5%. The 90% LMR model identified the following variables as significant: the presence/absence of borrow pits, location of failure on meander bend, channel width, land-cover type, constriction-over-time factor, vegetative buffer width, channel sinuosity, and presence/absence of bank revetment. This model had an R2 value of 0.385, p-value of 0.006, and a percentage accuracy of 72.0%. The MMR and LMR models with the 95% significance threshold had no predictors in common because of differences between the two river reaches or possibly because of the small sample size. However, the expanded MMR and LMR models shared three predictors (i.e., meander location, channel width, and land cover type). The second portion of this project used post-processed dual-frequency GPS surveying to measure levee elevations between St. Louis, MO and Cairo, IL. These elevations were compared to the 50-year design flood grade elevations and to a 1998 DEM to identify areas of levee heightening, levee degradation and/or subsidence, and locations of past levee crevasses. This surveying revealed areas that, between 1998 and 2007, were raised up to ~1.5 meters and other areas that degraded or subsided up to ~1.0 meter. Also, the locations of five recent levee crevasses were investigated, showing local increases or decreases at those points. The importance of levee road construction type was identified through many sharp increases or decreases at the transition between road types. Overall, this project showed promising implications for the determination of levee failure susceptibility and proper levee elevation heights using logistic regression analysis and kinematic GPS surveying. The logistic regression models predicted the potential for levee failure based on local site characteristics of levees between St. Louis, MO and Memphis, TN. The high-precision kinematic GPS surveying illustrated levee elevations along the MMR to a high degree of accuracy, allowing for the rapid and efficient identification of areas that do not correspond to the proper design flood grade elevation.

Working within the National Longitudinal Transition Study (NLTS) theoretical framework, the purpose of this study was to explore the effects of individual characteristics, in-school experiences, post-school experiences, and contextual factors on Vocational Rehabilitation (VR) closure status among 4,443 young adults with disabilities who had received and completed services from Oregon VR between 2003 and 2013. This study analyzed extant data from the Oregon Rehabilitation Case Automation System (ORCA), an integrated case management database that collects and tracks demographic characteristics, service records and employment data on each individual who receives services from VR. Four logistic regression models were developed using Hosmer, Lemeshow, and Studivant's model building approach to test the effects of individual characteristics, in-school experiences, post-school experiences, and contextual factors on VR closure status. Seven risk factors were identified that decrease the probability of young adults with disabilities achieving a positive VR closure status: (1) being female; (2) having a primary disability of mental illness; (3) having a primary disability of traumatic brain injury; (4) having an interpersonal impediment to employment; (5) receiving Supplemental Security Income at application; (6) closing VR services during federal fiscal year (FFY) 2008; and (7) closing VR services during FFY 2009. Five protective factors were identified that increase the probability of young adults with disabilities achieving a positive VR closure status: (1) participation in the Oregon Youth Transition Program; (2) earning at least a high school completion certificate by closure; (3) receiving a higher number of VR services; (4) closing VR services on or below the median number of days to closure; and (5) closing VR services during FFY 2004. These findings support the hypothesis that individual characteristics, in-school experiences, post-school experiences, and contextual factors are predictors of positive VR closure status among young adults with disabilities. Further, these results provide evidence that transition services and supports provided to young adults with disabilities receiving services from VR can help them to achieve positive VR closure status.

This thesis investigates the factors that are associated with annual changes in the share price of Johannesburg Stock Exchange (JSE) listed companies. In this study, an increase in value of a share is when the share price of a company goes up by the end of the financial year as compared to the previous year. Secondary data that was sourced from McGregor BFA website was used. The data was from 2004 up to 2011. Deciding which share to buy is the biggest challenge faced by both investment companies and individuals when investing on the stock exchange. This thesis uses binary logistic regression to identify the variables that are associated with share price increase. The dependent variable was annual change in share price (ACSP) and the independent variables were assets per capital employed ratio, debt per assets ratio, debt per equity ratio, dividend yield, earnings per share, earnings yield, operating profit margin, price earnings ratio, return on assets, return on equity and return on capital employed. Different variable selection methods were used and it was established that the backward elimination method produced the best model. It was established that the probability of success of a share is higher if the shareholders are anticipating a higher return on capital employed, and high earnings/ share. It was however, noted that the share price is negatively impacted by dividend yield and earnings yield. Since the odds of an increase in share price is higher if there is a higher return on capital employed and high earning per share, investors and investment companies are encouraged to choose companies with high earnings per share and the best returns on capital employed. The final model had a classification rate of 68.3% and the validation sample produced a classification rate of 65.2% / Mathematical Sciences / M.Sc. (Statistics)

Master of Science / Department of Statistics / Trevor Hefley / Binary regression models for spatial data are commonly used in disciplines such as epidemiology and ecology. Many spatially-referenced binary data sets suffer from location error, which occurs when the recorded location of an observation differs from its true location. When location error occurs, values of the covariates associated with the true spatial locations of the observations cannot be obtained. We show how a change of support (COS) can be applied to regression models for binary data to provide bias-corrected coefficient estimates when the true values of the covariates are unavailable, but the unknown location of the observations are contained within non-overlapping polygons of any geometry. The COS accommodates spatial and non-spatial covariates and preserves the convenient interpretation of methods such as logistic and probit regression. Using a simulation experiment, we compare binary regression models with a COS to naive approaches that ignore location error. We illustrate the flexibility of the COS by modeling individual-level disease risk in a population using a binary data set where the location of the observations are unknown, but contained within administrative units. Our simulation experiment and data illustration corroborate that conventional regression models for binary data which ignore location error are unreliable, but that the COS can be used to eliminate bias while preserving model choice.

Made available in DSpace on 2014-06-11T19:31:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-21Bitstream added on 2014-06-13T19:02:00Z : No. of bitstreams: 1 bravin_lfn_dr_botfca.pdf: 1587223 bytes, checksum: 0a57d84559c7e11913147515a220326a (MD5) / Universidade Estadual Paulista (UNESP) / O objetivo do trabalho é avaliar o estágio em que se encontra a logística no agronegócio brasileiro.Tem como foco a hidrovia Tietê-Paraná, suas características técnicas, as transformações recentes com a evolução à logística integrada e as vantagens competitivas obtidas na operação desse modal integrado com outro meio de transporte para a redução do custo final de frete. No desenvolvimento do trabalho foram estudadas rotas de transporte de cargas agrícolas do Estado de Goiás e Mina Gerais com destino ao Estado de São Paulo, que é o maior mercado consumidor do Brasil e estão inseridos na bacia hidrográfica dos rios Tietê e Paraná. A rota selecionada tem percursos com distâncias médias de 720 quilômetros que são atendidas pelos modais de transporte rodoviário, ferroviário e hidroviário. Para o estudo do modelo logístico foram comparados dados do custo de frete do modelo utilizado atualmente - rodoviário e ferroviário ao do modelo proposto no trabalho - hidroviário.Analisou-se também as vantagens ambientais e operacionais, o seu tempo de percurso no transporte de cargas e as interferências causadas pelas plantas aquáticas no leito navegável da hidrovia. Os valores de fretes praticados pelo modal rodoviário são de R$.t 0,10 ou R$ 72,00 a tonelada, do ferroviário, de R$.t 0,063 ou R$ 45,75 a tonelada a tonelada e no modal hidroviário, o custo de frete, atendendo os mesmos requisitos de origem e destino da carga, é de R$.t 0,040 ou R$ 28,80 a tonelada. As vantagens ambientais e econômicas são inúmeras, podendo ser destacado a quantidade de quilos transportados por Hp (horse power) na hidrovia, cerca de 4.000 quilos por unidade de Hp, muito acima do modal rodoviário que movimenta perto de 150 quilos com a mesma potência. Isto resulta em grande economia de combustível, menores impactos ambientais. A interferência ambiental na hidrovia ocorre... / The objective of the work is to evaluate the period of training that if finds the logistic one in the agribusiness having as focus of study the waterway Tietê-Paraná, its characteristics techniques, the recent transformations with the evolution to the logistic one integrated and the gotten competitive advantages in the operation of this modal one integrated with another way of transport for the reduction it final cost of freight. In the development of the work routes of agricultural load transport of the state of Goiás with destination to the state of São Paulo had been studied, which represents the biggest consuming market of Brazil and she is inserted in the area of influences the rivers Tietê and Paraná. The selected route has passages with average distances of 720 kilometers that are taken care of by the modal ones of road transport, railroad worker and hidro modality. For the study of the logistic model they had been calculated and compared given of the cost of freight of the model used currently - road and railroad worker to the one of the model considered in the work - hidro modality; where if it carried through an analysis of the ambient advantages, operational, its time of passage in the load transport and the interferences caused for the increase of aquatic plants in the navigable stream bed of the waterway. The values of freights practised for the modal road are of R$.t0,10 or R$ 72,00 the ton, the values of the railroad worker are of R$.t 0,063 or R$ 45,75 the ton and in the hidro modality the freight cost taking care of the same requirements of origin and destination of the load is of R$.t 0,040 or R$ 28,80 the ton. The ambient advantages are innumerable, being able to be detached the amount of kilos carried by Hp (horse to power) in the hidrovia, which puts into motion 4,000 kg for unit of Hp differentiating of the modal road who puts into motion... (Complete abstract, click electronic access below)

abstract: Correlation is common in many types of data, including those collected through longitudinal studies or in a hierarchical structure. In the case of clustering, or repeated measurements, there is inherent correlation between observations within the same group, or between observations obtained on the same subject. Longitudinal studies also introduce association between the covariates and the outcomes across time. When multiple outcomes are of interest, association may exist between the various models. These correlations can lead to issues in model fitting and inference if not properly accounted for. This dissertation presents three papers discussing appropriate methods to properly consider different types of association. The first paper introduces an ANOVA based measure of intraclass correlation for three level hierarchical data with binary outcomes, and corresponding properties. This measure is useful for evaluating when the correlation due to clustering warrants a more complex model. This measure is used to investigate AIDS knowledge in a clustered study conducted in Bangladesh. The second paper develops the Partitioned generalized method of moments (Partitioned GMM) model for longitudinal studies. This model utilizes valid moment conditions to separately estimate the varying effects of each time-dependent covariate on the outcome over time using multiple coefficients. The model is fit to data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) to investigate risk factors of childhood obesity. In the third paper, the Partitioned GMM model is extended to jointly estimate regression models for multiple outcomes of interest. Thus, this approach takes into account both the correlation between the multivariate outcomes, as well as the correlation due to time-dependency in longitudinal studies. The model utilizes an expanded weight matrix and objective function composed of valid moment conditions to simultaneously estimate optimal regression coefficients. This approach is applied to Add Health data to simultaneously study drivers of outcomes including smoking, social alcohol usage, and obesity in children. / Dissertation/Thesis / Doctoral Dissertation Statistics 2018

The Analysis of Logistic Distribution of Dispenser Net in Grocery at The Certain Company

Subject of this thesis is analysis of logistic and distribution chain of Amway Corporation. Almost all around the world the company products are distributed through multilevel marketing, direct sales channel and e-shops. Detail analysis of production and product range is just highlighting exclusive position on the market. In addition different types and advantages of cooperation with Amway are analyzed in a detail, such as marketing plan, bonus calculation for distributors, etc. Competitiveness of products is underlined by price and product features comparative analysis. Main conclusions from practical part of thesis are for distributors is possibility to build up their own business and for advantages of using distributors.

The purpose of thesis was optimizing logistic system in the company ESAB Vamberk, s. r. o. This objective includes comparison of informational and material flows of chosen products. The weak part of the logistic system was delivering raw materials. My intention was to come up with optimal solution. The first option was sharing of production plan with suppliers of raw materials. The second option was outsourcing. In the present economic situation it is better to use outsourcing which decreases storing costs. Another weak part of the logistic system was the storing of the finished goods. The company ESAB Vamberk, s. r. o. divided its products into two groups A and C according to the turnover. The items with could be coded B are included in the group A. I have used the ABC method and I have divided all the items into three groups according mentioned turnover. I have also came up with changes in placing the products in the storage of finished goods because some products are placed on the atypical pallets. In the present time the company ESAB Vamberk, s. r. o. holds high safety stock for drawn wire which is in the group A. The safety stock keeps the financial resources, which could company use for decreasing impacts of economical recession. This is why I came up with suggestion to decrease the safety stock by 50 %. On the other hand the information flow was very good. Because of using the EDI system and follow-up programs the data flows through the company continuously. The material flow has got shortcomings, which were mentioned above.