Analysis of Environmental and Economic Efficiency: Application of the Overseer model and simulated data

New Zealand’s success in raising agricultural productivity has been accompanied by higher input use, leading to adverse effects on the environment. Until recently, analysis of farm performance has tended to ignore such negative externalities. The current emphasis on environmental issues has led dairy farmers to target improvements in both environmental performance and productivity. Therefore measuring the environmental performance of farms and integrating this information into farm productivity calculations should assist informed policy decisions which promote sustainable development. However this is a challenging process since conventional environmental efficiency measures are usually based on simple input and output flows but nitrogen discharge is a complex process which depends on climate variability, pasture and cow physiology and geophysical variability. Furthermore the outdoor, pastoral nature of New Zealand farming means that it is difficult to control input and output flows, particularly of nitrogen. Therefore this paper proposes a novel approach to measure environmental and economic efficiency of farms using the Overseer nutrient budget model and a spatially micro-simulated virtual population data. Empirical analysis is based on dairy farms in the Karapiro catchment, where nitrogen discharge from dairy farming is major source of nonpoint pollution.Data Envelopment Analysis, Economic, Efficiency, Environment, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Land Economics/Use, Livestock Production/Industries, Research Methods/ Statistical Methods,

A Lightweight Policy System for Body Sensor Networks

Body sensor networks (BSNs) for healthcare have more stringent security and context adaptation requirements than required in large-scale sensor networks for environment monitoring. Policy-based management enables flexible adaptive behavior by supporting dynamic loading, enabling and disabling of policies without shutting down nodes. This overcomes many of the limitations of sensor operating systems, such as TinyOS, which do not support dynamic modification of code. Alternative schemes for adaptation, such as network programming, have a high communication cost and suffer from operational interruption. In addition, a policy-driven approach enables finegrained access control through specifying authorization policies. This paper presents the design, implementation and evaluation of an efficient policy system called Finger which enables policy interpretation and enforcement on distributed sensors to support sensor level adaptation and fine-grained access control. It features support for dynamic management of policies, minimization of resources usage, high responsiveness and node autonomy. The policy system is integrated as a TinyOS component, exposing simple, well-defined interfaces which can easily be used by application developers. The system performance in terms of processing latency and resource usage is evaluated. © 2009 IEEE.Published versio

A practitioner's guide to intergovernmental fiscal transfers

Intergovernmental fiscal transfers are a dominant feature of subnational finance in most countries. They are used to ensure that revenues roughly match the expenditure needs of various orders (levels) of subnational governments. They are also used to advance national, regional, and local area objectives, such as fairness and equity, and creating a common economic union. The structure of these transfers creates incentives for national, regional, and local governments that have a bearing on fiscal management, macroeconomic stability, distributional equity, allocative efficiency, and public services delivery. This paper reviews the conceptual, empirical, and practice literature to distill lessons of policy interest in designing the fiscal transfers to create the right incentives for prudent fiscal management and competitive and innovative service delivery. It provides practical guidance on the design of performance-oriented transfers that emphasize bottom-up, client-focused, and results-based government accountability. It cites examples of simple but innovative grant designs that can satisfy grantors'objectives while preserving local autonomy and creating an enabling environment for responsive, responsible, equitable, and accountable public governance. The paper further provides guidance on the design and practice of equalizationtransfers for regional fiscal equity as well as the institutional arrangements for implementation of such transfer mechanisms. It concludes with negative (practices to avoid) and positive (practices to emulate) lessons from international practices.Public Sector Economics&Finance,Intergovernmental Fiscal Relations and Local Finance Management,Public Sector Management and Reform,Public&Municipal Finance,Urban Economics

PRESERVING WATER QUALITY IN AGRICULTURE: BIOBED ROTATION TO VERTICAL

Up to 95% of the contamination of surface water by pesticides comes from on-farm point sources in connection with washing and preparation operations. This contamination is a growing concern for environment and human health. Because of their efficiency, their low cost and their friendly and simple use, Biobeds were recognized as the best tool to treat these pesticide effluents. Assuming a single passage of the effluent through the Biobed followed by release of the percolate, the research focused on the efficiency of the depuration after a single percolation. Accounting for unknown hazards such as metabolites and bound residues leads, however, local rules in Europe to enjoin a recycling of the effluent until full evaporation to prevent any release in the environment. Managed as such, we show that the Biobeds are waterlogged and no longer perform the elimination of the effluent. This induces large hazards of either direct volatilization or effluent release, and goes with increased costs, dissatisfaction or demotivation of the farmers, thus jeopardizing the development of this solution. Accounting for these new depuration conditions leads to a new Biobed paradigm, namely optimization of the transpiration of the water rather than optimization of the single percolation depuration, which leads to sharp changes in Biobed forms, content and management. Moreover, the corresponding new system shows larger performance, decreased space and maintenance requirements, and improved aesthetics. This is shown in the present study based on compared monitoring of the systems performance, hydrodynamics and substrate conditions during use.Resource /Energy Economics and Policy,

A Hardware Implementation of a Run-Time Scheduler for Reconfigurable Systems

New generation embedded systems demand high performance, efficiency and flexibility. Reconfigurable hardware can provide all these features. However the costly reconfiguration process and the lack of management support have prevented a broader use of these resources. To solve these issues we have developed a scheduler that deals with task-graphs at run-time, steering its execution in the reconfigurable resources while carrying out both prefetch and replacement techniques that cooperate to hide most of the reconfiguration delays. In our scheduling environment task-graphs are analyzed at design-time to extract useful information. This information is used at run-time to obtain near-optimal schedules, escaping from local-optimum decisions, while only carrying out simple computations. Moreover, we have developed a hardware implementation of the scheduler that applies all the optimization techniques while introducing a delay of only a few clock cycles. In the experiments our scheduler clearly outperforms conventional run-time schedulers based on As-Soon-As-Possible techniques. In addition, our replacement policy, specially designed for reconfigurable systems, achieves almost optimal results both regarding reuse and performance

Simulation Based Study of Safety Stocks under Short-Term Demand Volatility in Integrated Device Manufacturing.

© IEOM Society InternationalA problem faced by integrated device manufacturers (IDMs) relates to fluctuating demand and can be reflected in long-term demand, middle-term demand, and short-term demand fluctuations. This paper explores safety stock under short term demand fluctuations in integrated device manufacturing. The manufacturing flow of integrated circuits is conceptualized into front end and back end operations with a die bank in between. Using a model of the back-end operations of integrated circuit manufacturing, simulation experiments were conducted based on three scenarios namely a production environment of low demand volatility and high capacity reliability (Scenario A), an environment with lower capacity reliability than scenario A (Scenario B), and an environment of high demand volatility and low capacity reliability (Scenario C). Results show trade-off relation between inventory levels and delivery performance with varied degree of severity between the different scenarios studied. Generally, higher safety stock levels are required to achieve competitive delivery performance as uncertainty in demand increases and manufacturing capability reliability decreases. Back-end cycle time are also found to have detrimental impact on delivery performance as the cycle time increases. It is suggested that success of finished goods safety stock policy relies significantly on having appropriate capacity amongst others to support fluctuations

Tools for distributed application management

Distributed application management consists of monitoring and controlling an application as it executes in a distributed environment. It encompasses such activities as configuration, initialization, performance monitoring, resource scheduling, and failure response. The Meta system (a collection of tools for constructing distributed application management software) is described. Meta provides the mechanism, while the programmer specifies the policy for application management. The policy is manifested as a control program which is a soft real-time reactive program. The underlying application is instrumented with a variety of built-in and user-defined sensors and actuators. These define the interface between the control program and the application. The control program also has access to a database describing the structure of the application and the characteristics of its environment. Some of the more difficult problems for application management occur when preexisting, nondistributed programs are integrated into a distributed application for which they may not have been intended. Meta allows management functions to be retrofitted to such programs with a minimum of effort