Twin line (two seed lines 7.25 in apart per bed) and conventional single seed line per bed cotton production systems were compared at 18 sites across Arizona and the Palo Verde Valley near Blythe, Ca. in 2002 and 9 sites in 2003. Three experiments at the Chaffin site in 2002 compared twin line plant populations of 57,000 (57K), 75,000 (75K), and 90,000 (90K) plants per acre (ppa). In 2002, the twin line system produced more lint than the conventional single line system at 4 of 18 locations; the yields of the twin line and single line systems were 1273 and 1186 lb/acre, 1572 and 1461 lb/acre, 1478 and 1290 lb/acre, and 1309 and 1210 lb/acre, respectively, at the Grasty, Ramona, Rovey, and Wells sites, respectively. In 2003, none of the experiments resulted in higher twin line system lint yields. In 2002, there were no significant differences in yield or fiber micronaire in 7 of the 18 experiments. In 2003, there were no significant differences in yield in 3 of the 9 experiments. In 2002, the twin line system produced less lint than the conventional system at 5 of 18 locations; yields of the twin line and single line systems were 2019 and 2189 lb/acre, 1400 and 1489 lb/acre, 1537 and 1845 lb/acre, 1065 and 1200 lb/acre, and 1271 and 1431 lb/acre, respectively, at the Chaffin (75K), Cooley, Hull, Papago, and Wakimoto sites, respectively. In 2003, the twin line system resulted in less yield in 6 of the 9 experiments; yields of the twin line and single line systems were 1154 and 1285 lb./acre, 1906 and 2109 lb./acre, 1797 and 1938 lb./acre, 878 and 1114 lb./acre, 726 and 821 lb./acre, and 1230 and 1404 lb./acre, respectively, at the Hull, Marlatt 1, 2,, 3, Murphy Late Plant, and the University of Arizona (UA) Marana Agricultural Center sites respectively. In 2002, fiber micronaire was reduced in five experiments; the micronaire values were 4.25 and 4.73, 4.46 and 4.78, 4.60 and 4.85, 4.76 and 4.98, and 4.93 and 5.15, in the twin line and single line systems, respectively, at the Rogers, Papago, Grasty, Hull, and Perry sites, respectively. In 2003, there were no significant differences in fiber micronaire at all 9 test locations. In 2003, visual observations suggested that the spindle pickers were unable to effectively harvest bolls the lowest bolls primarily below the cross-over point of the two2 mainstems cross in the twin line system. Hand harvest comparisons of the twin and single line system resulted in yields of 1776 and 1661 lb./acre respectively, a 6% difference at the Maricopa Agricultural Center. It was concluded that tThe inability to effectively harvest the twin line cotton is the most significant system problem with this production system.

Reverse production systems are often comprised of several tiers with independent members competing at each tier. This research develops and designs a decision-making process for decentralized reverse production systems where each participant in the network determines its decisions in a self-interested way. This dissertation includes three major parts. The first part develops a prototype model for a decentralized reverse production system with two tiers, collectors and processors, focusing on the coordination of transactions of recycled items between these two tiers. The collectors determine the individual material flow allocation mechanisms, based on predictions of the range of prices from the processors, that relate the flow amount to the overall vector of acquisition prices that will be offered by the processors to all the collectors. The processors compete for the flow from the collectors and reach an equilibrium state where no entity is willing to change its decisions. In the second part, we extend the prototype model for a general multi-tiered recycling network comprised of the upstream boundary tier, several intermediate tiers, and the downstream boundary tier where each of the tiers has multiple independent entities. Recycled items flow from the top tier to the downstream tier, but acquisition prices are set from the downstream tier back to the upstream tier. Finally the third part provides a comparison of centralized and decentralized models for reverse production systems and addresses several numerical insights of different system subsidy schemes.

No description available.

Thesis (Mestre em Agronomia)--Universidade de São Paulo, 1984. / Includes bibliographical references (leaves 111-115).

In the context of the paper, a research work is shown to implement a networked decentralized safety architecture that replaces the central architecture. Thus, the safety system fits better into the rest of the automation structure. On the one hand, this is done by a clearer hardware structure, as there is now one safety controller per decentralized unit, which, analogous to the distributed automation system, communicates with the other stations via an Ethernet-based bus system, thus greatly reducing the wiring and commissioning effort. On the other hand, the decentralized processing allows a local shutdown of the safety-relevant components and an escalation of the emergency shutdown to other areas, depending on the emergency stop situation. This means that in the event of a safety-critical situation, the shutdown is reduced to what is necessary from a safety point of view, which increases system availability.

A majority of the established automotive manufacturers are under severe competitive pressure and their long term economic sustainability is threatened. In particular the transformation towards more CO2-efficient energy sources is a huge financial burden for an already investment capital intensive industry. In addition existing operations urgently need rapid improvement and even more critical is the development of highly productive, efficient and sustainable manufacturing solutions for new and updated products. Simultaneously, a number of severe drawbacks with current improvement methods for industrial production systems have been identified. In summary, variation is not considered sufficient with current analysis methods, tools used are insufficient for revealing enough knowledge to support decisions, procedures for finding optimal solutions are not considered, and information about bottlenecks is often required, but no accurate methods for the identification of bottlenecks are used in practice, because they do not normally generate any improvement actions. Current methods follow a trial-and-error pattern instead of a proactive approach. Decisions are often made directly on the basis of raw static historical data without an awareness of optimal alternatives and their effects. These issues could most likely lead to inadequate production solutions, low effectiveness, and high costs, resulting in poor competitiveness. In order to address the shortcomings of existing methods, a methodology and framework for manufacturing management decision support using simulation-based multi-objective optimisation is proposed. The framework incorporates modelling and the optimisation of production systems, costs, and sustainability. Decision support is created through the extraction of knowledge from optimised data. A novel method and algorithm for the detection of constraints and bottlenecks is proposed as part of the framework. This enables optimal improvement activities with ranking in order of importance can be sought. The new method can achieve a higher improvement rate, when applied to industrial improvement situations, compared to the well-established shifting bottleneck technique. A number of 'laboratory' experiments and real-world industrial applications have been conducted in order to explore, develop, and verify the proposed framework. The identified gaps can be addressed with the proposed methodology. By using simulation-based methods, stochastic behaviour and variability is taken into account and knowledge for the creation of decision support is gathered through post-optimality analysis. Several conflicting objectives can be considered simultaneously through the application of multi-objective optimisation, while objectives related to running cost, investments and other sustainability parameters can be included through the use of the new cost and sustainability models introduced. Experiments and tests have been undertaken and have shown that the proposed framework can assist the creation of manufacturing management decision support and that such a methodology can contribute significantly to regaining profitability when applied within the automotive industry. It can be concluded that a proof-of-concept has been rigorously established for the application of the proposed framework on real-world industrial decision-making, in a manufacturing management context.

Thesis (MScAgric (Agronomy))--Stellenbosch University, 2008. / The use of hydroponic strawberry production systems is increasing worldwide. Although higher planting densities are possible in vertical production systems, these higher planting densities may have a negative effect on individual plant yield and fruit quality due to lower light levels when compared to conventional (horizontal) production systems. Optimum planting densities will for this reason be affected by light intensities inside the greenhouse and configuration of the vertical production systems. Two experiments were conducted in a plastic cladded greenhouse, fitted with a wetwall and fan cooling system, at the Department of Agronomy, University of Stellenbosch, South Africa during the period of April 2007 to November 2007 (late autumn to early summer). Mean daily maximum temperatures exceeded 26 oC during most of the 14 week harvest period (22 August to 30 November 2007), while photosynthetic active radiation (PAR), measured at 12h00 on cloudless days, inside the greenhouse increased from about 200 μMol m-2 s-1 to about 460 μMol m-2 s-1 during this period. The first experiment compared the effect of two vertical production systems (vertical system and ‘A-shape’ system), subjected to different planting density (16.7, 23.3 and 33.3 plants m-2) and shading (0%, 20%, 50%) treatments, as measured on selected yield, quality and growth factors. The second experiment studied the effect of different planting density (3.3, 5.6 and 10 plants m-2) and shading (0%, 20%, 50%) treatments on the same yield, quality and growth factors in a conventional production system. A comparison with regard to these factors was also made between the highest planting densities of the conventional-, vertical- and ‘A-shape’ system.

Purpose: Since the perception of what characterizes a modern building changes with time, it’s important for companies in the housing business to be updated on how the market and customer preferences change. For companies, with long-run standardized production systems, to not lose market shares as a result of the inability to change the exterior appearance of the product a new building should be produced to meet the customers’ requirements. The aim of the study is to create an aesthetically modernized building and study how it changes the production process and affect the cost of production. Method: The methods used in the study consist of qualitative data collection in the form of in-depth analyzes of literature studies, semi-structured interviews and collection of documents. Through the use of these methods a theoretical background and empirical data have been compiled into a result. Findings: The elements that are considered as modern according to literature and customer preferences are horizontal panels, well thought out window placement with abundant glass surfaces and details that affect the aesthetic appearance. To introduce these elements to production the standard needs to be reviewed and more alternatives added. The findings show that with exterior changes, in regards to modernity, does not increase the cost of production more than that the company, for which the study was conducted, is able to keep the total price lower than competitors. Implications: Higher flexibility in the production process needs to be introduced to meet the demand of the market. The work that’s considered to be flexible today may mean standards tomorrow. The conclusion is that companies should keep their standardized production patterns with elements of flexible work. A more detailed study in a technological solution may be followed by this study. Limitations: The study has been conducted in cooperation with a company in the catalogue home industry where only exterior changes for a single storey house are taken into consideration of the study. A further limitation is that a detailed cost calculation is excluded. Keywords: standardization, prefabrication, construction elements, production systems, customer segments, modernization.

Este trabalho introduz a formalização algébrica do F-MFG (Functional Mark Flow Graph) para a análise e simulação computacional de modelos de sistemas antropocêntricos de produção, onde são enfocadas a interação e a interface do elemento humano com o sistema produtivo. Abordando os sistemas antropocêntricos como uma classe de sistemas a eventos discretos, o F-MFG, que é uma técnica baseada nas redes de Petri, comprova ter potencial para descrever detalhadamente as ações e estados do sistema. O F-MFG, em conjunto com a Metodologia PFS/MFG (Production Flow Schema/ Mark Flow Graph), estabelece um procedimento eficiente para o projeto de sistemas antropocêntricos, tornando concisa a modelagem e a posterior avaliação estrutural e comportamental do sistema. / This work introduces an algebraic formalization of F-MFG (Functional-Mark Flow Graph). This formalization is effective for analysis and simulation of anthropocentric production systems, which is focused on the interaction and interface between human elements and production systems. When approaching anthropocentric systems as Discrete Event Dynamic Systems, the F-MFG, which is a Petri Net based technique, has been demonstrated its potential capabilities in describing detailed models of system actions and states. The PFS/MFG Methodology (Production Flow Schema/Mark Flow Graph Methodology) combined with F-MFG establishes an efficient procedure for the design of anthropocentric systems. This procedure results in concise modeling and analysis (system structural and behavioral evaluation) processes.

A agricultura está relacionada à concentração atmosférica de gases de efeito estufa (GEE) através dos processos básicos que ocorrem no sistema solo-planta. Mudanças no uso e manejo do solo podem causar tanto efeito negativo como positivo no que se refere à emissão de gases de efeito estufa para a atmosfera. O objetivo deste trabalho foi avaliar o fluxo de óxido nitroso e metano em diferentes sistemas de produção agropecuários e na vegetação natural durante as estações do ano, analisando os fatores edafoclimáticos que influenciam as emissões desses gases de efeito estufa. O experimento foi desenvolvido na Empresa Brasileira de Pesquisa Agropecuária, na cidade de São Carlos - SP (21 ° 57\'S, 47 ° 50\'W), no período de outubro de 2013 a agosto de 2014, onde se avaliou o fluxo de gases de efeito estufa em todas as estações do ano. Foram avaliadas as emissões de óxido nitroso (N2O) e metano (CH4) das pastagens pelo solo dos sistemas de integração lavoura-pecuária floresta - ILPF, integração lavoura-pecuária - ILP, silvipastoril - IPF, pastagem sob manejo intensivo - INT, pastagem sob manejo extensivo - EXT e a vegetação natural (Floresta Estacional Semidecidual do Bioma Mata Atlântica) - Floresta. O delineamento experimental foi em blocos ao acaso com repetições. Foram usadas duas repetições para cada área de pastagem, que consistiram nos blocos. Os fluxos líquidos de emissão de óxido nitroso e metano foram coletados de amostras de ar provenientes de \"câmaras estáticas\", seis por tratamento, sendo três câmaras (repetições) por bloco (área de pastagem ou parcelas na floresta) em cada amostragem. As coletas das amostras gasosas foram feitas em três tempos (0, 30 e 60 minutos) durante 10 dias em cada estação do ano (meados) e analisadas por cromatografia gasosa. Simultaneamente às coletas de gases, coletaram-se amostras de solo em áreas adjacentes para determinação dos teores de N-total, N-NH+4 e N-NO-3 e da umidade gravimétrica. Nessas amostras foram mensuradas a fertilidade do solo, as densidades aparente e de partícula do solo e a porcentagem do espaço poroso do solo ocupado por água. Nas taxas de emissões de metano, os sistemas de produção intensivo e extensivo tiveram as maiores contribuições, ambos com uma emissão média diária de 0,067g de CH4 ha-1 d-1. O verão foi a estação do ano que apresentou a maior emissão de metano, com uma taxa média de 0,110 g CH4 ha-1 d-1. Em relação ao óxido nitroso, os sistemas de iLP e intensivo, apresentaram os menores índices de emissão, 0,007 g de N2O ha-1 d-1. Entre as estações do ano, não houve diferença estatística na emissão média de N2O. Dentre as variáveis edafoclimáticas correlacionadas com a emissão dos gases, somente temperatura média e máxima apresentaram correlação significativa com o fluxo de N2O ha-1 d-1 e para o metano, temperatura média e mínima, umidade relativa do ar, precipitação, espaço poroso do solo, amônio e nitrato do solo obtiveram correlação com a emissão de CH4 ha-1 d-1, entretanto as correlações foram muito fracas. Houve interação entre as estações do ano e os sistemas de produção para os fluxos dos gases de efeito estufa. As emissões de metano e óxido nitroso foram bastante baixas em todos os sistemas de produção e na floresta e variaram em função das estações do ano, havendo pequenos fluxos de emissão e, em algumas ocasiões, influxos na dinâmica dos gases metano e óxido nitroso. / Agriculture is related to the atmospheric concentration of greenhouse gases (GHG) through the basic processes that occur in the soil-plant system. Changes in land use and management can cause both negative and positive effects on GHG emission into the atmosphere. The objective of this work was to evaluate the flow of nitrous oxide (N2O) and methane (CH4) in different agricultural production systems and in the natural vegetation during the four seasons, analyzing the edaphoclimatic factors that influence the emissions of these gases. The experiment was carried out at the Brazilian Agricultural Research Corporation, in São Carlos, SP (21 ° 57\'S, 47 ° 50\'W), from October 2013 to August 2014. Nitrous oxide and methane emissions were evaluated in the soil of the crop-livestock-forest (CLF), crop-livestock (CL) and livestock-forest (LF) integrated systems, traditional intensively manged pasture (INT), pasture under extensive management - EXT and the natural vegetation - Seasonal Semideciduous Forest of the Atlantic Forest Biome - FOR. The experimental design was in randomized blocks (two replicates per treatment). Nitrous oxide and CH4 emission net flows were collected from air samples from six \"static chambers\" allocated per treatment (three replicates) per block (pasture area or forest plots) at each sampling. The gas samples were collected three times (0, 30 and 60 minutes) and analyzed by gas chromatography. Simultaneously to the gas sampling, soil samples were collected in adjacent areas to determine N-total, N-NH+4 and N-NO-3 contents and gravimetric moisture. The soil fertility, apparent and particle densities and the percentage of soil porous space occupied by water were measured. In the methane emission rates, intensive and extensive production systems had the highest contributions, both with an average daily emission of 0.067g CH4 ha-1 d-1. Summer was the season with the highest methane emission, with an average rate of 0.110 g CH4 ha-1 d-1. In relation to nitrous oxide, the iLP and intensive systems had the lowest emission rates, 0.007 g of N2O ha-1 d-1. Among the seasons, there was no statistical difference in the mean emission of N2O. Among the edaphoclimatic variables correlated with the gas emission, only mean and maximum temperature showed a significant correlation with the N2O ha-1 d-1 flow and for methane, mean and minimum temperature, relative humidity, precipitation, pore space Soil, ammonium and soil nitrate obtained correlation with the emission of CH4 ha-1 d-1, however the correlations were very weak. There was interaction between the seasons of the year and the production systems for the flows of greenhouse gases. The emissions of methane and nitrous oxide were quite low in all production systems and in the forest and varied according to the seasons, with small emission fluxes and, at times, influxes in the dynamics of methane and nitrous oxide gases.