Search results for "production [pi]"

Relations entre les variations climatiques, les perturbations du cycle du carbone et les crises de la production carbonatée : application au Crétacé …

2011

The Early Cretaceous is punctuated by carbon cycle perturbations, associated with organic matter burial episodes and carbonate production crises. These events coincide with short-term cooling (<1Ma), yet the mechanisms are still unclear, because of low resolution in sea surface temperature reconstructions. Recent climatic models suggest that carbonate-platform-collapse events may trigger a short-term ocean cooling episode (Donnadieu et al., accepted). In order to establish relations between climates and carbonate productions, we performed stratigraphic, palaeoecologic and geochemical analyses on Valanginian sediments from the La Charce-Vergol and the Ollioules sections (South-East France) a…

An expert system for vineyard management based upon pervasive computer technologies

2009

Determining the optimal maturity level for performing viticulture operations and harvesting activities is a difficult task, because, depending on the variety, the climatic conditions and cultural practices, the phenologic maturation process occurs at different times. Recently, ubiquitous computing technologies allow an extremely precise and cost effective monitoring of environmental conditions by means of an RFID based sensor networks. The implementation of such technologies in vineyard management is nowadays under development, however, besides the possibility of gathering data, the need is perceived of developing decision support tools to fully exploit the potential opportunities of these …

Ranking and comparing key factors causing time-overruns in on-site construction

2022

For years, the construction industry has looked for ways to avoid time-overruns in construction. Despite previous research mapping the factors affecting time performance, site-managers have difficulties in reducing the time-overrun. In order to create a clearer guidance on how to control time-performance, this study investigates the resource related factors because they are within the site-manager’s control. Three Case studies were followed and a survey including 36 participants where conducted. Both investigated and ranked the likelihood of delay due to the seven different resource factors. The ranking of the resource factors was identified as: (1) Construction design, (2) Connecting works…

Production Planning in Production Networks: Models for Medium and Short-term Planning

2008

Distributed production networks are structures which are considered able to provide the organisational agility and efficiency necessary to compete in the global market. The performance of such organisations heavily depends on the ability of those involved in the network to coordinate their activities. Two approaches are available for managing complex distributed production networks: a centralised approach, where a unique entity (the planner, for instance) has all the necessary information to make planning decisions for the entire network; or a decentralised approach where each entity in the network has the necessary information and knowledge to make autonomous planning decisions, while the …

U.S. stock prices and macroeconomic fundamentals: Fresh evidence using the quantile ARDL approach

2020

This paper explores the long‐run relationship and the associated short‐run dynamics between the U.S. stock market and three major macroeconomic fundamentals, namely the U.S. industrial production index, the U.S. 10‐year Treasury bond yield and the West Texas Intermediate oil price, for the time period covering 1985–2015. The quantile autoregressive distributed lag (QARDL) model presented by Cho et al. (2015) Journal of Econometrics, 188, 281–300, which combines the autoregressive distributed lag model of Pesaran and Shin (1998), Cambridge University Press, and Pesaran et al. (2001) Journal of Applied Econometrics, 16, 289–326, and the quantile regression methodology of Koenker and Bassett (…

Operation management in reconfigurable manufacturing systems: Reconfiguration for error handling

2006

Abstract Reconfigurable manufacturing systems offer quick adjustment of production capacity and functionality in response to unpredictable market changes as being systems designed at the outset for rapid change in system configuration, its machines and controls. During the production process, out-of-ordinary events occur dynamically and unpredictably both at the system (machine breakdowns, change in job's priorities, etc.) and at the cell level (tool failures, robot collisions, etc.). Such exceptions interrupt the production process by causing errors in the schedule plan (system level) or in the task plan (cell level). Error handling is the policy meant for reacting to errors caused by the …

2014

This paper presents a mathematical model for robust production planning. The model helps fashion apparel suppliers in making decisions concerning allocation of production orders to different production plants characterized by different lead times and production costs, and in proper time scheduling and sequencing of these production orders. The model aims at optimizing these decisions concerning objectives of minimal production costs and minimal tardiness. It considers several factors such as the stochastic nature of customer demand, differences in production and transport costs and transport times between production plants in different regions. Finally, the model is applied to a case study.…

Negotiation in Distributed Production Planning Environments

2006

Mass customization and global competition push enterprises to adopt proper business models able to capture all the opportunities arising from emerging competition rules. An increasing number of industrial enterprises distribute their production capacity world wide to achieve lower production costs, lower distribution costs (due to the closer proximity to customers), and deeper knowledge of customer needs. As a drawback, coordination of the different production plants and the balance among plants and enterprise goals represent a critical issue in the network management. In this context the paper looks at the production planning problem, adopting a traditional hierarchical time-based perspect…

Integrated Approach to Part Scheduling and Inspection Policies for a Job Shop Manufacturing System

2007

The quality of a product greatly depends on the quality of its components. This requires that manufacturing specifications have to be met in the manufacturing environment and as a consequence inspection stations are present in many manufacturing systems and inspection policies must be adopted. One problem, which has been widely investigated, concerns the detection of the inspection points in the hypothesis that the action to be taken is known when a defective part is detected. If different jobs are to be produced, then operation scheduling becomes yet another complex problem needing to be solved. And while the problem of scheduling has received a great amount of attention from researchers, …

Coordination policies to support decision making in distributed production planning

2003

Abstract Distributed production networks are considered organizational structures able to match agility and efficiency necessary to compete in the global market. Performances of such organization structures heavily depend on the ability of the network actors of coordinating their activities. The research proposes to model and design coordination problems within production network by using the Multiple Agent Technology. In particular, the paper proposes new strategies for coordinating production-planning activities within production networks. Such models have been developed and tested by using a proper simulation environment developed by using open source code and architecture. The results o…