Multiscale approach to the security of hardware supply chains for energy systems

While the cybersecurity field has focused primarily on software and network security, threats and vulnerabilities of hardware device supply chains are growing concerns. Of particular importance and interest in this vein is the way in which semiconductors and other electronic devices are increasingly deployed to support energy distribution, storage, and control at a variety of scales. Future smart grid supply chains must be secured to prevent cyber attacks from affecting energy infrastructure, and the societal and economic functions on which they depend. This perspective paper calls for a multiscale approach to address modeling and decision-making for energy system hardware supply chains. A multiscale approach, as discussed in this paper, can facilitate resilience of supply chains across the life cycles of these systems, through low- and high-tech techniques to monitor and act on the supply chain. This can incorporate both qualitative and quantitative factors to suit the variety of stakeholders, geographic scales, organizational levels, and planning and operational time horizons.     

Measurement of filtration rates by infaunal bivalves in a recirculating flume

A flume system and protocol for measuring the filtration rate of infaunal bivalves is described. Assemblages of multi-sized clams, at natural densities and in normal filter-feeding positions, removed phytoplankton suspended in a unidirectional flow of water. The free-stream velocity and friction velocity of the flow, and bottom roughness height were similar to those in natural estuarine waters. Continuous variations in phytoplankton (Chroomonas salinay) cell density were used to measure the filtration rate of the suspension-feeding clam Potamocorbula amurensis for periods of 2 to 28 h. Filtration rates of P. amurensis varied from 100 to 580 liters (gd)^-1 over a free-stream velocity range of 9 to 25 cm s^-1. Phytoplankton loss rates were usually constant throughout the experiments. Our results suggest that suspension-feeding by infaunal bivalves is sensitive to flow velocity.     

Clean air with economic growth: Optimization modeling

Conflicts between the goals of having clean air and economic development are widespread. This paper discusses the conceptual and mathematical development of a linear programming optimization model and an interative solution procedure to determine optimal economic development strategies to promote employment subject to various contexts which limit air pollution carrying capacity. Three cases are formulated: (1) maximizing employment subject to ambient concentration constraints, (2) maximizing employment subject to emissions constraints, and (3) minimizing emissions subject to employment constraints. Empirical relationships using Census and pollutant inventory data describe a conceptual urban system, so that indirect and induced impacts of development strategies are also included. The modeling incorporates both point and nonpoint sources, and is shown to be adaptable for nonreactive emissions.     

An examination of community flood warning systems: Are we providing the right assistance?

The technology transfer of flood warning systems offers a large potential for reducing human losses and property damage in flood-prone regions; much of the technology and methodology is readily transferable from developed countries and “appropriate” for developing countries. This paper examines some community folk warning systems in the United States that could be incorporated into a rational strategy for technology transfer. It discusses why official organized systems should not be relied on completely and how participation in and transfer of highly cost-effective and reliable community warning systems by development assistance agencies could greatly benefit the people as well as the governments of developing countries.     

Campsite impact on three western Wilderness areas

Campsites were studied in subalpine forests in the Eagle Cap Wilderness in Oregon, and in the Mission Mountains Tribal Wilderness and the Rattlesnake Wilderness in Montana. Research objectives were to examine ecological changes on these sites and the extent to which these changes become more pronounced as use increases For most parameters measured, impact on campsites used for only a few nights per year exceeds threshold values beyond which further increases in use have little effect Loss of litter, tree root exposure, and site enlargement are the major types of alteration that are more pronounced on sites occupied more frequently than several nights per year In heavily used parts of backcountry areas, this suggests that ecological change can be minimized by limiting use to a small number of sites In the three areas studied, campsite occupancy rates would probably have to be no higher than a few nights per year before dispersal of use among a large number of sites would be an ecologically sound strategy     

Water Resources Research Prioritization and Management-Problems and Perspectives1

ABSTRACT: At a time when productive water resources research is essential to protecting the quality of and wisely using our limited water resources, pervasive trends toward consumerism, fiscal restraint, centralized management, and using research for other social objectives threaten research productivity. The research prioritization and management structure that these trends have created was examined in the microcosm of its application at the Utah Water Research Laboratory. The result indicated that ephemeral prioritization and the failure of research users to target researchers to their own particular needs is diluting productivity. Incremental research prioritization and greater use of advisory councils in facilitating user-researcher interaction are suggested as corrective approaches, but the only firm conclusion at this point in time must be that empirical studies of the performance of alternatives in research management structure are solely needed.     

Statistical Analysis of Spatial Pattern: A Comparison of Grid and Hierarchical Sampling Approaches

Previous studies have combined random-site hierarchical sampling designs with analysis of variance techniques, and grid sampling with spatial autocorrelation analysis. We illustrate that analysis techniques and sampling designs are interchangeable using densities of an infaunal bivalve from a study in Poverty Bay, New Zealand. Hierarchical designs allow the estimation of variances associated with each level, but high-level factors are imprecisely estimated, and they are inefficient for describing spatial pattern. Grid designs are efficient for describing spatial pattern, and are amenable to conventional analysis. Our example deals with a continuous spatial habitat, but our conclusions also apply in disjunct or patchy habitats. The influence of errors in positioning is also assessed. The advantages of systematic sampling are reviewed, and more efficient hierarchical approaches are identified. The distinction between biological and statisticalsignificance in all analyses is emphasised.     

On the propagation of error in air pollution measurements

Four methods for estimating the uncertainties in air pollution measurements are outlined. The approaches are: analytical solution-approximation; application of distribution theory; experimentation; and simulation. The advantages and disadvantages of each method are illustrated using data from High-Volume air samplers, the instrument most commonly used for monitoring ambient concentrations of airborne particles.Dr Evans is Assistant Professor of Environmental Science and Mr Kinney is a doctoral candidate in the Department of Environmental Science and Physiology, Harvard School of Public Health. Dr Cooper is at the Manufacturing Research Laboratory, Thomas J. Watson Research Center, IBM, Yorktown Heights, NY.