Página 12 dos resultados de 13926 itens digitais encontrados em 0.010 segundos

## Development of a traffic emission inventory for a mexican city

Jaime, Aideé Morales
Português
Relevância na Pesquisa
26.7%
Air pollution has been one of the priorities issues in the environmental awareness, especially in cities from developing countries. Transport sector has an important contribution to the urban air quality degradation in these countries. Hence the importance to develop traffic emission inventories in order to allow the identification and quantification of atmospheric pollutant emissions in a defined area. The aim of this work is to develop a traffic emission inventory for the city of Querétaro, Mexico, using two different approaches (top-down and bottom-up) and to compare the results obtained from using both methodologies. Vehicle emissions from top-down inventory for the state of Querétaro show an increase compared to vehicle emissions reported in the 1999 Mexican National Emission Inventory due to the accelerated growth and development of the city of Querétaro. Emissions from the municipalities located in the south of the state of Querétaro are higher than in the rest of the municipalities, probably due to the higher number of highways and roads existing in this area. Vehicle emissions from bottom-up inventory using IVE model and considering different type of roads show that arterial roads are the main contributors of emission due to vehicle activity...

## The GreenCut2 Resource, a Phylogenomically Derived Inventory of Proteins Specific to the Plant Lineage*

Karpowicz, Steven J.; Prochnik, Simon E.; Grossman, Arthur R.; Merchant, Sabeeha S.
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.7%
The plastid is a defining structure of photosynthetic eukaryotes and houses many plant-specific processes, including the light reactions, carbon fixation, pigment synthesis, and other primary metabolic processes. Identifying proteins associated with catalytic, structural, and regulatory functions that are unique to plastid-containing organisms is necessary to fully define the scope of plant biochemistry. Here, we performed phylogenomics on 20 genomes to compile a new inventory of 597 nucleus-encoded proteins conserved in plants and green algae but not in non-photosynthetic organisms. 286 of these proteins are of known function, whereas 311 are not characterized. This inventory was validated as applicable and relevant to diverse photosynthetic eukaryotes using an additional eight genomes from distantly related plants (including Micromonas, Selaginella, and soybean). Manual curation of the known proteins in the inventory established its importance to plastid biochemistry. To predict functions for the 52% of proteins of unknown function, we used sequence motifs, subcellular localization, co-expression analysis, and RNA abundance data. We demonstrate that 18% of the proteins in the inventory have functions outside the plastid and/or beyond green tissues. Although 32% of proteins in the inventory have homologs in all cyanobacteria...

## From Models to Measurements: Comparing Downed Dead Wood Carbon Stock Estimates in the U.S. Forest Inventory

Domke, Grant M.; Woodall, Christopher W.; Walters, Brian F.; Smith, James E.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.7%
The inventory and monitoring of coarse woody debris (CWD) carbon (C) stocks is an essential component of any comprehensive National Greenhouse Gas Inventory (NGHGI). Due to the expense and difficulty associated with conducting field inventories of CWD pools, CWD C stocks are often modeled as a function of more commonly measured stand attributes such as live tree C density. In order to assess potential benefits of adopting a field-based inventory of CWD C stocks in lieu of the current model-based approach, a national inventory of downed dead wood C across the U.S. was compared to estimates calculated from models associated with the U.S.’s NGHGI and used in the USDA Forest Service, Forest Inventory and Analysis program. The model-based population estimate of C stocks for CWD (i.e., pieces and slash piles) in the conterminous U.S. was 9 percent (145.1 Tg) greater than the field-based estimate. The relatively small absolute difference was driven by contrasting results for each CWD component. The model-based population estimate of C stocks from CWD pieces was 17 percent (230.3 Tg) greater than the field-based estimate, while the model-based estimate of C stocks from CWD slash piles was 27 percent (85.2 Tg) smaller than the field-based estimate. In general...

## Development and validation of a lead emission inventory for the Greater Cairo area

Safar, Zeinab; Labib, Mounir W.; Gertler, Alan W.
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.7%

## Inventory Reduction and Productivity Growth: Linkages in the Japanese Automotive Industry

Demeester, Lieven; Lieberman, Marvin B.
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Formato: 2304712 bytes; application/pdf
Português
Relevância na Pesquisa
26.7%
The literature on JIT production suggests a causal link between work-in-process inventory and manufacturing productivity. Such a connection has been described in numerous case studies but never tested statistically. This paper uses historical data for 52 Japanese automotive companies to evaluate the inventory-productivity relationship. We find that firms increased their productivity rank during periods of substantial inventory reduction. More detailed tests suggest that inventory reductions stimulated gains in productivity: on average, each 10% reduction in inventory led to about a 10% gain in labor productivity, with a lag of about one year. Such effects were more immediate for Toyota affiliates but undetectable for close suppliers of Nissan. These findings imply that inventory reduction served as an important driver of process improvement for many Japanese automotive companies, although some firms emphasized other methods.

## Measuring impact of CONWIP control on production rate and inventory distribution for a flexible production system through simulation; Measuring impact of CONstant Work in Process control on production rate and inventory distribution for a flexible production system through simulation

Lampe, Erik Joseph
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 30 leaves
Português
Relevância na Pesquisa
26.7%
This research investigates the production output and inventory distribution of a manufacturing system that produces multiple part types on flexible machines while incorporating CONWIP inventory controls. The production machines, which are separated by individual storage areas for each part type, are modeled as unreliable and operate according to a strict priority sequence. The maximum total inventory of each part type in the entire system is limited a preset number of tokens in the system. While varying the token levels and the demand for finished parts, the average production output for each part type and the average inventory level for each buffer is monitored to understand their behaviors. The relationship between the inventory distributions and the production rates is also investigated. The goal of this research is to develop intuition behind the system behavior.; by Erik Joseph Lampe.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (leaf 30).

## LP-based subgradient algorithm for joint pricing and inventory control problems; Linear programming-based subgradient algorithm for joint pricing and inventory control problems

Rao, Tingting
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 94 p.
Português
Relevância na Pesquisa
26.7%
It is important for companies to manage their revenues and -reduce their costs efficiently. These goals can be achieved through effective pricing and inventory control strategies. This thesis studies a joint multi-period pricing and inventory control problem for a make-to-stock manufacturing system. Multiple products are produced under shared production capacity over a finite time horizon. The demand for each product is a function of the prices and no back orders are allowed. Inventory and production costs are linear functions of the levels of inventory and production, respectively. In this thesis, we introduce an iterative gradient-based algorithm. A key idea is that given a demand realization, the cost minimization part of the problem becomes a linear transportation problem. Given this idea, if we knew the optimal demand, we could solve the production problem efficiently. At each iteration of the algorithm, given a demand vector we solve a linear transportation problem and use its dual variables in order to solve a quadratic optimization problem that optimizes the revenue part and generates a new pricing policy. We illustrate computationally that this algorithm obtains the optimal production and pricing policy over the finite time horizon efficiently. The computational experiments in this thesis use a wide range of simulated data. The results show that the algorithm we study in this thesis indeed computes the optimal solution for the joint pricing and inventory control problem and is efficient as compared to solving a reformulation of the problem directly using commercial software. The algorithm proposed in this thesis solves large scale problems and can handle a wide range of nonlinear demand functions.; by Tingting Rao.; Thesis (S.M.)--Massachusetts Institute of Technology...

## Statistical Modelling of Europe-wide Landslide Susceptibility Using Limited Landslide Inventory Data

VAN DEN EECKHAUT MIET; HERVAS DE DIEGO Francisco; JAEDICKE Christian; MALET Jean-Philippe; MONTANARELLA Luca; NADIM Farrokh
Fonte: SPRINGER HEIDELBERG Publicador: SPRINGER HEIDELBERG
Tipo: Articles in Journals Formato: Printed
Português
Relevância na Pesquisa
26.7%
In many regions, the absence of a landslide inventory hampers the production of susceptibility or hazard maps. Therefore, a method combining a procedure for sampling of landslide-affected and landslide-free grid cells from a limited landslide inventory and logistic regression modelling was tested for susceptibility mapping of slide- and flow-type landslides on a European scale. Landslide inventories were available for Norway, Campania (Italy) and the Barcelonnette Basin (France) and from each inventory a random subsample was extracted. In addition, a landslide dataset was produced from the analysis of Google Earth images in combination with extraction of landslide locations reported in scientific publications. Attention was paid to have a representative distribution of landslides over Europe. In total, the landslide-affected sample contained 1340 landslides. Then, a procedure to select landslide-free grid cells was designed taking account of the incompleteness of the landslide inventory and the high proportion of flat areas in Europe. Using stepwise logistic regression, a model including slope gradient, standard deviation of slope gradient, lithology, soil and land cover types was calibrated. The classified susceptibility map produced from the model was then validated by visual comparison with national landslide inventory or susceptibility maps available from literature. The first results are promising and suggest that in case of landslide disasters the method can be used for urgently required landslide susceptibility mapping in regions where currently only sparse landslide inventory data are available.; JRC.H.7-Climate Risk Management

## Navy inventory management decision-making

MacDonald, Steven D
Português
Relevância na Pesquisa
26.7%
Approved for public release; distribution is unlimited; The General Accounting Office (GAO) has stated that the Department of Defense (DoD) believes it is better to overbuy inventory items than to manage with just the right amount of stock. This thesis asserts that Navy inventory managers do not have a general tendency to overbuy items, but rather make rational purchasing decisions influenced and motivated by the environment of rewards and penalties in which they work. It is also asserted that Navy inventory managers are risk adverse due to the nature of their environment. Personal stockout costs are examined as one of the key factors influencing decision-making and risk adverse behavior. This thesis introduces a conceptual model that describes the Navy inventory management decision-making environment. This model shows the relationship between personal stockout costs, required service levels, cost considerations, and planning horizons across the different decision-making levels in the Navy. This study concludes that readiness-based performance measures must be changed to incorporate a cost focus, and that the risk facing inventory managers due to personal stockout costs needs to be reduced to change their behavior of lower inventory levels are desired

## A continuous review model for the reparable item inventory system.

Freiheit, James Edward
Português
Relevância na Pesquisa
26.7%
Approved for public release, distribution is unlimited.; In general, a reparable inventory system deals with two classes of the same type of item. The first class consists of those items which have been procured from the manufacturer and have never been put to use. The second class consists of those items which have been used, have failed, have been repaired, and are ready to be used again. In addition to the two classes of items, the system also contains two distinct inventories. These are the ready-for-issue and the non-ready-for-issue inventories. The ready-for-issue inventory contains both classes of items in their usable state, and the non-ready-for-issue inventory contains only the latter in its failed but reparable state. This paper develops a quasi-probabilistic inventory model for the reparable inventory system based on the premise that the repair facility is the primary source of inventory, with procurements being made periodically only to supplement this primary source.

## Inventory accuracy in NISTARS controlled non-mechanized warehouses

Westhoven, Stephen Douglas
Português
Relevância na Pesquisa
26.7%
Approved for public release, distribution unlimited; This thesis studies the inventory accuracy in nonmechanized warehouses under the NISTARS automated warehousing system. This thesis is designed to answer two questions. Is there a significant difference between the NISTARS non-mechanized warehouses and the other types of warehouses? What are the reasons for the difference if one exists? The data were extracted from the official inventory reports of the Naval Supply Center, San Diego, CA. To ensure the data were representative of the inventory position of all warehouses under the control of the supply center, they were taken from the NAVSUP required quarterly STATMAN random sampled inventories. The study indicates that there is a significant difference (13% less) in the inventory accuracy in non-mechanized warehouses under NISTARS control. Also, that the research codes used in the inventory reports are not effective. Additionally, the data output from the inventory reports is not fully used to improve the system

## Potential applicability of just-in-time inventory management within the Navy

Giacoman, Rebeca M.
Português
Relevância na Pesquisa
26.7%
There is growing concern over inventory management policies within the Navy as well as questions as to how to improve supply management efficiency. Just-in-time is an inventory management system that has enabled private industries to reduce inventories and waste to become more efficient and profitable. The primary focus of this study is to determine the potential for JIT application within the Navy based on certain criteria necessary for a successful JIT system. Navy organizations are categorized and certain aspects of their resupply functions are analyzed to determine the appropriate inventory management system. A comparison is made of the Navy inventory management system to the elements of a JIT resupply system. An assessment is made to determine eligibility of Navy operations for a JIT inventory management system. Finally, a case study of Naval Aviation Depot North Island, an organization that exhibits potential for JIT, is examined for the specific conditions necessary to permit a JIT resupply system. The study of the NADEP reveals a viable potential for a JIT system within the component repair function. Further research involving review of the current inventory management procedures for the NADEP is recommended.

## US Navy Ships Food Service Divisions: Modernizing Inventory Management

Stefan Edwards; Robert James
Português
Relevância na Pesquisa
26.7%
Sponsored Report (for Acquisition Research Program); The Navy's current inventory management procedures for receipt, inventory, stowage, and issue of provisions onboard ships have remained relatively unchanged for decades. Culinary Specialists are utilizing an antiquated and unreliable inventory management program (the Food Management System'FSM) developed in the 1990s, relying on hand-written receipts, and inventory and issue procedures to manage provisions across the Fleet. As a result of current practices, ships are experiencing an unusually high rate of inspection failures and poor inventory validities. Applying a strategic supply-chain management approach, we will describe current procedures, from receipt to issue of provisions, including collecting and analyzing qualitative and quantitative data. We will offer conclusions and recommendations on ways to substantially improve the overall process (e.g., improve inventory validities, reduce man-hours and improve the quality of life for Culinary Specialists).

## Corporate social responsibility and inventory policy

Barcos, Lucía; Barroso, Alicia; Surroca, Jordi; Tribó, Josep A.
Tipo: Trabalho em Andamento Formato: application/octet-stream; application/pdf
Relevância na Pesquisa
26.7%
In this article, we study the impact of implementing corporate social responsible (CSR) practices on a firm’s inventory policy. Our proposal is that there is an inverted U-shape relationship between firms’ CSR and their inventory levels. Two elements explain such proposal. First, stakeholders have different interests regarding the outcome of the inventory system. Specifically, we hypothesize that customers pressure firms to increase inventories; employees have conflicting views regarding inventories and, for this reason, they do not pressure firms in a particular direction; and environmental activists force firms to reduce inventories. The second reason is that there is different level of stakeholder proactiveness contingent on the intensity in the implementation of social responsible policies. In particular, we posit that for low levels of CSR, customers are more relevant, while for larger levels other stakeholders gain more importance. We test this theoretical prediction by crossing two databases, COMPUSTAT, for financial data, and KLD for data on social responsibility. Our final database contains data on 1881 different US companies for the period 1996-2006. The results found conform to our theoretical prediction. Our analysis will be helpful to strategic and tactical decision-making processes on inventory management and will allow researchers to offer concrete advice on the likely outcomes of various stakeholder relationship practices in order to improve the effectiveness of inventory systems. Additionally...

## The use of simulation to evaluate inventory models for management of hazardous material

Collins, Bobbi L.; Stroh, Gregory F.
Tipo: Tese de Doutorado Formato: 166 p.
Português
Relevância na Pesquisa
26.7%
A problem for the Navy Supply System is identifying the proper inventory model for managing a Hazardous Material Minimization Center. This thesis analyzes three recently proposed inventory models: two continuous review economic order quantity (EOQ) inventory models and a periodic review inventory model. Based on this analysis, the authors develop both a continuous review EOQ model and a periodic review model for evaluation. These models differ from the previous ones in that they comprise all of the relevant hazardous material inventory costs including extension of shelf-life. The two new models are then evaluated through the use of simulation. A base set of data was first used in simulating both models. This was then followed by four additional simulated scenarios providing sensitivity analyses of demand-related changes to each model. The thesis' analysis focuses on total variable costs as the primary tool for evaluating the models. The results in all cases were very close, suggesting that it can be left to the inventory managers as to whether to use a continuous review or periodic review model. Additional testing with actual demand data is strongly recommended before any implementation of either model.; NA; NA; U.S. Navy (U.S.N.) authors.

## Application of a system-based inventory model to Marine Corps repairable parts

Barnett, Craig P.