Embedding Population Dynamics Models in Inference

Increasing pressures on the environment are generating an ever-increasing need to manage animal and plant populations sustainably, and to protect and rebuild endangered populations. Effective management requires reliable mathematical models, so that the effects of management action can be predicted, and the uncertainty in these predictions quantified. These models must be able to predict the response of populations to anthropogenic change, while handling the major sources of uncertainty. We describe a simple ``building block'' approach to formulating discrete-time models. We show how to estimate the parameters of such models from time series of data, and how to quantify uncertainty in those estimates and in numbers of individuals of different types in populations, using computer-intensive Bayesian methods. We also discuss advantages and pitfalls of the approach, and give an example using the British grey seal population.Comment: Published at http://dx.doi.org/10.1214/088342306000000673 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Coordinating pricing and inventory decisions in a multi-level supply chain: A game-theoretic approach

This paper concerns coordination of enterprise decisions such as suppliers and components selection, pricing and inventory in a multi-level supply chain composed of multiple suppliers, a single manufacturer and multiple retailers. The problem is modeled as a three-level dynamic non-cooperative game. Analytical and computational methods are developed to determine the Nash equilibrium of the game. Finally, a numerical study in computer industry is conducted to understand the influence of the market scale parameter and the components selection strategy on the optimal decisions and profits of the supply chain as well as its constituent members. Several research findings have been obtained. © 2010 Elsevier Ltd.link_to_subscribed_fulltex

A web-based information system to support end-of-life product recovery

Increased public awareness towards global environmental problems has forced manufacturing companies to consider the negative impacts of their activities on the environment. In this context, the effective management of products at the end of their useful life has become of paramount importance due to the ever-increasing national and international legislation and directives aimed at making take-back and recovery of used products obligatory for the original equipment manufacturer. This highlights a need for a systematic approach for enhancement of information, business and production management systems to deal with additional activities and processes related to the recovery of products. The research reported in this paper has developed a five-stage methodology to support product end-of-life management within manufacturing companies. The modelling and design of appropriate product recovery information systems, which constitute the main core of this methodology, are also described. The paper concludes with the description of an application of this methodology and information system design for the recovery of cutting tools at the end of their useful life in metalworking applications

Distributed autonomous real-time planning and control of small to medium enterprises

The research reported in this paper is built on the use of the concepts of ‘holonic manufacturing’ and is seeking new methods to reinforce the autonomous and cooperative attributes of planning and control activities within human centred manufacturing facilities. It is claimed that in small enterprises, where the success depends on the skill of individual employees and their ability to collaborate, the manufacturing performance can be improved by the use of the appropriate information technology (IT) tools and the appropriate planning and control structure, designed and developed on the basis of these holonic concepts. Such novel tools and planning structures must provide the most appropriate information in a way that enhances collaborative activity within the business and strengthens the role of the individual. This paper identifies a number of major requirements that must be considered for the design and implementation of an effective production planning and control (PPC) structure, tailored for the needs of small enterprises. Based on these requirements and the use of holonic manufacturing concepts, a novel distributed autonomous real-time planning and control structure is presented. The final sections of the paper describe the implementation of such a planning and control structure within a typical configuration for the production facility of a small metalworking enterprise

The adoption of STEP-NC for the manufacture of asymmetric rotational components

This paper reports ongoing research on the use of the evolving ISO 14649 standard, informally termed STEP-NC, which represents a new data model for the next generation of computer numerical controllers. The paper presents the major challenges in implementing STEPcompliant CAD/CAM (computer-aided design/manufacture) systems for manufacturing asymmetric rotational parts. It also discusses the need for a new ISO 14649 schema specific for asymmetric rotational parts and outlines a feasible solution to use the ISO 14649 data model for turn/mill machining

Theology, News and Notes - Vol. 46, No. 02

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1136/thumbnail.jp

Calibration of pelagic stereo-BRUVs and scientific longline surveys for sampling sharks

Our understanding of the ecology of sharks and other highly mobile marine species often relies on fishery-dependent data or extractive fishery-independent techniques that can result in catchability and size-selectivity biases. Pelagic Baited Remote Underwater stereo-Video Systems (pelagic stereo-BRUVs) provide a standardized, non-destructive and fishery-independent approach to estimate biodiversity measures of fish assemblages in the water column. However, the performance of this novel method has not yet been assessed relative to other standard sampling techniques. We compared the catch composition, relative abundance and length distribution of fish assemblages sampled using pelagic stereo-BRUVs and conventional scientific longline surveys. In particular, we focused on sharks of the family Carcharhinidae (requiem sharks) to assess the sampling effectiveness of this novel technique along a latitudinal gradient off the coast of Western Australia. We calibrated the sampling effort required for each technique to obtain equivalent samples of the target species and discuss the advantages, limitations and potential use of these methods to study highly mobile species.The proportion of sharks sampled by pelagic stereo-BRUVs and scientific longline surveys was comparable across the latitudinal gradient. Carcharhinus plumbeus was the most abundant species sampled by both the techniques. Longline surveys selected larger individuals of the family Carcharhinidae in comparison with the length distribution data obtained from pelagic stereo-BRUVs. However, the relative abundance estimates (catch per unit of effort) from the pelagic stereo-BRUVs were comparable to those from 5 to 30 longline hooks. Pelagic stereo-BRUVs can be calibrated to standard techniques in order to study the species composition, behaviour, relative abundance and size distribution of highly mobile fish assemblages at broad spatial and temporal scales. This technique offers a non-destructive fishery-independent approach that can be implemented in areas that may be closed to fishing and is suitable for studies on rare or threatened species