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21.
《Journal of Industrial Ecology》2004,8(1-2):11-21
Land use is an increasingly important component of sustainability evaluations, and numerous performance metrics have evolved to meet this need. The selection of appropriate land-use metrics for decision makers, however, remains an ongoing challenge. Additionally, life-cycle practitioners often struggle to provide meaningful impact assessment because of challenges associated with traditional land-use impact metrics. This article is intended to assist decision makers and life-cycle practitioners who wish to more effectively measure and evaluate one aspect of land use: surface area occupation. Existing performance metrics are discussed, and the specific circumstances under which each is appropriate are identified. Building on leading-edge research and analysis in the field of life-cycle impact assessment, a modified methodology for evaluating surface area occupation is proposed. This approach is demonstrated for a series of mining practices including three individual gold mines, a bauxite mine, and a copper mine. The specific data requirements and resulting equivalency factors for each mine are discussed. Results indicate that equivalency factors for gold (average of 700 acre-yr/ton) are expected to be several orders of magnitude higher than for either bauxite (0.004 acre-yr/ ton) or copper (0.03 acre-yr/ton). These dramatic differences in results demonstrate that equivalency factors are appropriate and necessary for including land-use impact potential as part of a life-cycle assessment that includes several different minerals or material requirements. 相似文献
22.
粒度变化对上海市景观格局分析的影响 总被引:6,自引:1,他引:5
采用1989年上海市1∶50 000彩红外航空遥感影像解译的土地利用数据,系统分析了粒度变化对中心城区、郊区和城郊结合部3类景观格局分析的影响.结果表明:景观格局指数对粒度具有尺度依赖性,随粒度的变粗,格局指数的变化可归为单调下降、阶梯上升或单峰变化以及不规则变化3类;景观格局指数随粒度变化的曲线存在多个拐点,并对应于合适的景观格局分析尺度,上海城市景观格局分析的合适尺度为10~20 m;不同城市景观类型对景观格局指数的粒度效应具有较大影响,景观格局指数在城郊结合部表现出与城区和郊区不同的变化趋势. 相似文献
23.
In the study of food webs, the existence and explanation of recurring patterns, such as the scale invariance of linkage density, predator–prey ratios and mean chain length, constitute long-standing issues. Our study focused on litter-associated food webs and explored the influence of detritivore and predator niche width (as δ13C range) on web topological structure. To compare patterns within and between aquatic and terrestrial ecosystems and take account of intra-habitat variability, we constructed 42 macroinvertebrate patch-scale webs in four different habitats (lake, lagoon, beech forest and cornfield), using an experimental approach with litterbags. The results suggest that although web differences exist between ecosystems, patterns are more similar within than between aquatic and terrestrial web types. In accordance with optimal foraging theory, we found that the niche width of predators and prey increased with the number of predators and prey taxa as a proportion of total taxa in the community. The tendency was more marked in terrestrial ecosystems and can be explained by a lower per capita food level than in aquatic ecosystems, particularly evident for predators. In accordance with these results, the number of links increased with the number of species but with a significantly sharper regression slope for terrestrial ecosystems. As a consequence, linkage density, which was found to be directly correlated to niche width, increased with the total number of species in terrestrial webs, whereas it did not change significantly in aquatic ones, where connectance scaled negatively with the total number of species. In both types of ecosystem, web robustness to rare species removal increased with connectance and the niche width of predators. In conclusion, although limited to litter-associated macroinvertebrate assemblages, this study highlights structural differences and similarities between aquatic and terrestrial detrital webs, providing field evidence of the central role of niche width in determining the structure of detritus-based food webs and posing foraging optimisation constraints as a general mechanistic explanation of food web complexity differences within and between ecosystem types. 相似文献
24.
Curtis C. Travis 《人类与生态风险评估》2011,17(2):467-477
Internal dose metrics, as computed with pharmacokinetic models, are increasingly used as a means for extrapolating animal toxicological data to humans and to extrapolate across routes of administration. These internal dose metrics are thought to provide a more scientific means of comparing toxicological effects across animal species. The use of internal dose metrics is based on the universal assumption that toxic effects are equal across species if and only if the concentration of the toxic moieties in the target tissue is equal across species. Herein it is shown that this assumption is inconsistent with empirical toxicological data. It is shown that measurement of internal dose metrics in chronological time, as is done for AUC (Area under the concentration curve) and rate of metabolite production per kg of target tissue, does not produce equal toxic effects across species. A consequence of this observation is that the application of pharmacokinetics in risk assessments for such important chemicals as trichloroethylene, vinyl chloride, perchloroethylene, and perchlorate may need reassessment. 相似文献
25.
Landscape ecology planning principles in Korean Feng-Shui, Bi-bo woodlands and ponds 总被引:1,自引:0,他引:1
The purpose of this study is to suggest practical planning principles, which are absent in landscape ecology planning, according to which the spatial completeness of the watershed is derived from native Korean Feng-Shui (). Landscape ecology planning principles are used widely in contemporary planning projects in terms of patch, corridor, matrix and network of landscape pattern. However, landscape indices for planning principles are complicated and constrained, and so are limited to applications for site and eco-village plannings. Native Korean Feng-Shui is different from Chinese Feng-Shui in that it is aimed at theoretical completeness in terms of aspect and topographical shape, based on the concept of ideal Myung-dang () to complete the space, according to local conditions in the physiognomy of the watershed. The complementary method is called Bi-bo () in native Korean Feng-Shui. These principles have been applied in traditional Korean villages, leading to consistent location choices and fractal patterns in land use. Furthermore, Bi-bo woodlands and ponds have been introduced to achieve spatial completeness in the landscape structure of the village. 相似文献
26.
A flexible multi-dimensional QoS performance measure framework for distributed heterogeneous systems
Jong-Kook Kim Debra A. Hensgen Taylor Kidd Howard Jay Siegel David St. John Cynthia Irvine Tim Levin N. Wayne Porter Viktor K. Prasanna Richard F. Freund 《Cluster computing》2006,9(3):281-296
When users’ tasks in a distributed heterogeneous computing environment (e.g., cluster of heterogeneous computers) are allocated
resources, the total demand placed on some system resources by the tasks, for a given interval of time, may exceed the availability
of those resources. In such a case, some tasks may receive degraded service or be dropped from the system. One part of a measure
to quantify the success of a resource management system (RMS) in such a distributed environment is the collective value of
the tasks completed during an interval of time, as perceived by the user, application, or policy maker. The Flexible Integrated
System Capability (FISC) measure presented here is a measure for quantifying this collective value. The FISC measure is a
flexible multi-dimensional measure such that any task attribute can be inserted and may include priorities, versions of a
task or data, deadlines, situational mode, security, application- and domain-specific QoS, and task dependencies. For an environment
where it is important to investigate how well data communication requests are satisfied, the data communication request satisfied
can be the basis of the FISC measure instead of tasks completed. The motivation behind the FISC measure is to determine the
performance of resource management schemes if tasks have multiple attributes that needs to be satisfied. The goal of this
measure is to compare the results of different resource management heuristics that are trying to achieve the same performance
objective but with different approaches.
This research was supported by the DARPA/ITO Quorum Program, by the DARPA/ISO BADD Program and the Office of Naval Research
under ONR grant number N00014-97-1-0804, by the DARPA/ITO AICE program under contract numbers DABT63-99-C-0010 and DABT63-99-C-0012,
and by the Colorado State University George T. Abell Endowment. Intel and Microsoft donated some of the equipment used in
this research.
Jong-Kook Kim is pursuing a Ph.D. degree from the School of Electrical and Computer Engineering at Purdue University (expected in August
2004). Jong-Kook received his M.S. degree in electrical and computer engineering from Purdue University in May 2000. He received
his B.S. degree in electronic engineering from Korea University, Seoul, Korea in 1998. He has presented his work at several
international conferences and has been a reviewer for numerous conferences and journals. His research interests include heterogeneous
distributed computing, computer architecture, performance measure, resource management, evolutionary heuristics, and power-aware
computing. He is a student member of the IEEE, IEEE Computer Society, and ACM.
Debra Hensgen is a member of the Research and Evaluation Team at OpenTV in Mountain View, California. OpenTV produces middleware for set-top
boxes in support of interactive television. She received her Ph.D. in the area of Distributed Operating Systems from the University
of Kentucky. Prior to moving to private industry, as an Associate Professor in the systems area, she worked with students
and colleagues to design and develop tools and systems for resource management, network re-routing algorithms and systems
that preserve quality of service guarantees, and visualization tools for performance debugging of parallel and distributed
systems. She has published numerous papers concerning her contributions to the Concurra toolkit for automatically generating
safe, efficient concurrent code, the Graze parallel processing performance debugger, the SAAM path information base, and the
SmartNet and MSHN Resource Management Systems.
Taylor Kidd is currently a Software Architect for Vidiom Systems in Portland Oregon. His current work involves the writing of multi-company
industrial specifications and the architecting of software systems for the digital cable television industry. He has been
involved in the establishment of international specifications for digital interactive television in both Europe and in the
US. Prior to his current position, Dr. Kidd has been a researcher for the US Navy as well as an Associate Professor at the
Naval Postgraduate School. Dr Kidd received his Ph.D. in Electrical Engineering in 1991 from the University of California,
San Diego.
H. J. Siegel was appointed the George T. Abell Endowed Chair Distinguished Professor of Electrical and Computer Engineering at Colorado
State University (CSU) in August 2001, where he is also a Professor of Computer Science. In December 2002, he became the first
Director of the CSU Information Science and Technology Center (ISTeC). ISTeC is a university-wide organization for promoting,
facilitating, and enhancing CSU’s research, education, and outreach activities pertaining to the design and innovative application
of computer, communication, and information systems. From 1976 to 2001, he was a professor at Purdue University. He received
two BS degrees from MIT, and the MA, MSE, and PhD degrees from Princeton University. His research interests include parallel
and distributed computing, heterogeneous computing, robust computing systems, parallel algorithms, parallel machine interconnection
networks, and reconfigurable parallel computer systems. He has co-authored over 300 published papers on parallel and distributed
computing and communication, is an IEEE Fellow, is an ACM Fellow, was a Coeditor-in-Chief of the Journal of Parallel and Distributed
Computing, and was on the Editorial Boards of both the IEEE Transactions on Parallel and Distributed Systems and the IEEE
Transactions on Computers. He was Program Chair/Co-Chair of three major international conferences, General Chair/Co-Chair
of four international conferences, and Chair/Co-Chair of five workshops. He has been an international keynote speaker and
tutorial lecturer, and has consulted for industry and government.
David St. John is Chief Information Officer for WeatherFlow, Inc., a weather services company specializing in coastal weather observations
and forecasts. He received a master’s degree in Engineering from the University of California, Irvine. He spent several years
as the head of staff on the Management System for Heterogeneous Networks project in the Computer Science Department of the
Naval Postgraduate School. His current relationship with cluster computing is as a user of the Regional Atmospheric Modeling
System (RAMS), a numerical weather model developed at Colorado State University. WeatherFlow runs RAMS operationally on a
Linux-based cluster.
Cynthia Irvine is a Professor of Computer Science at the Naval Postgraduate School in Monterey, California. She received her Ph.D. from
Case Western Reserve University and her B.A. in Physics from Rice University. She joined the faculty of the Naval Postgraduate
School in 1994. Previously she worked in industry on the development of high assurance secure systems. In 2001, Dr. Irvine
received the Naval Information Assurance Award. Dr. Irvine is the Director of the Center for Information Systems Security
Studies and Research at the Naval Postgraduate School. She has served on special panels for NSF, DARPA, and OSD. In the area
of computer security education Dr. Irvine has most recently served as the general chair of the Third World Conference on Information
Security Education and the Fifth Workshop on Education in Computer Security. She co-chaired the NSF workshop on Cyber-security
Workforce Needs Assessment and Educational Innovation and was a participant in the Computing Research Association/NSF sponsored
Grand Challenges in Information Assurance meeting. She is a member of the editorial board of the Journal of Information Warfare
and has served as a reviewer and/or program committee member of a variety of security related conferences. She has written
over 100 papers and articles and has supervised the work of over 80 students. Professor Irvine is a member of the ACM, the
AAS, a life member of the ASP, and a Senior Member of the IEEE.
Timothy E. Levin is a Research Associate Professor at the Naval Postgraduate School. He has spent over 18 years working in the design, development,
evaluation, and verification of secure computer systems, including operating systems, databases and networks. His current
research interests include high assurance system design and analysis, development of models and methods for the dynamic selection
of QoS security attributes, and the application of formal methods to the development of secure computer systems.
Viktor K. Prasanna received his BS in Electronics Engineering from the Bangalore University and his MS from the School of Automation, Indian
Institute of Science. He obtained his Ph.D. in Computer Science from the Pennsylvania State University in 1983. Currently,
he is a Professor in the Department of Electrical Engineering as well as in the Department of Computer Science at the University
of Southern California, Los Angeles. He is also an associate member of the Center for Applied Mathematical Sciences (CAMS)
at USC. He served as the Division Director for the Computer Engineering Division during 1994–98. His research interests include
parallel and distributed systems, embedded systems, configurable architectures and high performance computing. Dr. Prasanna
has published extensively and consulted for industries in the above areas. He has served on the organizing committees of several
international meetings in VLSI computations, parallel computation, and high performance computing. He is the Steering Co-chair
of the International Parallel and Distributed Processing Symposium [merged IEEE International Parallel Processing Symposium
(IPPS) and the Symposium on Parallel and Distributed Processing (SPDP)] and is the Steering Chair of the International Conference
on High Performance Computing(HiPC). He serves on the editorial boards of the Journal of Parallel and Distributed Computing
and the Proceedings of the IEEE. He is the Editor-in-Chief of the IEEE Transactions on Computers. He was the founding Chair
of the IEEE Computer Society Technical Committee on Parallel Processing. He is a Fellow of the IEEE.
Richard F. Freund is the originator of GridIQ’s network scheduling concepts that arose from mathematical and computing approaches he developed
for the Department of Defense in the early 1980’s. Dr. Freund has over twenty-five years experience in computational mathematics,
algorithm design, high performance computing, distributed computing, network planning, and heterogeneous scheduling. Since
1989, Dr. Freund has published over 45 journal articles in these fields. He has also been an editor of special editions of
IEEE Computer and the Journal of Parallel and Distributed Computing. In addition, he is a founder of the Heterogeneous Computing
Workshop, held annually in conjunction with the International Parallel Processing Symposium. Dr. Freund is the recipient of
many awards, which includes the prestigious Department of Defense Meritorious Civilian Service Award in 1984 and the Lauritsen-Bennet
Award from the Space and Naval Warfare Systems Command in San Diego, California. 相似文献
27.
Assessment of European streams with diatoms, macrophytes, macroinvertebrates and fish: a comparative metric-based analysis of organism response to stress 总被引:10,自引:0,他引:10
DANIEL HERING RICHARD K. JOHNSON SANDRA KRAMM STEFAN SCHMUTZ KRZYSZTOF SZOSZKIEWICZ PIET F. M. VERDONSCHOT 《Freshwater Biology》2006,51(9):1757-1785
1. Periphytic diatoms, macrophytes, benthic macroinvertebrates and fish were sampled with standard methods in 185 streams in nine European countries to compare their response to degradation. Streams were classified into two main stream type groups (i.e. lowland, mountain streams); in addition, the lowland streams were grouped into four more specific stream types. 2. Principal components analysis with altogether 43 environmental parameters was used to construct complex stressor gradients for physical–chemical, hydromorphological and land use data. About 30 metrics were calculated for each sample and organism group. Metric responses to different stress types were analysed by Spearman Rank Correlation. 3. All four organism groups showed significant response to eutrophication/organic pollution gradients. Generally, diatom metrics were most strongly correlated to eutrophication gradients (85% and 89% of the diatom metrics tested correlated significantly in mountain and lowland streams, respectively), followed by invertebrate metrics (91% and 59%). 4. Responses of the four organism groups to other gradients were less strong; all organism groups responded to varying degrees to land use changes, hydromorphological degradation on the microhabitat scale and general degradation gradients, while the response to hydromorphological gradients on the reach scale was mainly limited to benthic macroinvertebrates (50% and 44% of the metrics tested correlated significantly in mountain and lowland streams, respectively) and fish (29% and 47%). 5. Fish and macrophyte metrics generally showed a poor response to degradation gradients in mountain streams and a strong response in lowland streams. 6. General recommendations on European bioassessment of streams were derived from the results. 相似文献
28.
Detection of ecological change using multiple organism groups: metrics and uncertainty 总被引:10,自引:9,他引:1
A number of biological approaches are commonly used to assess the ecological integrity of stream ecosystems. Recently, it
is becoming increasingly common to use multiple organism groups in bioassessment. Advocates of the multiple organism approach
argue that the use of different organism groups should strengthen inference-based models and ultimately result in lower assessment
error, while opponents argue that organism groups often respond similarly to stress implying a high degree of redundancy.
Using fish, macroinvertebrate, macrophyte and benthic diatom data, site-specific parameters (e.g., water chemistry and substratum)
and catchment variables from European mountain (n = 77) and lowland (n = 85) streams we evaluated the discriminatory power and uncertainty associated with the use of a number of biological metrics
commonly used in stream assessment. The primary environmental gradient for both streams types was land use and nutrient enrichment.
Secondary and tertiary gradients were related to habitat quality or alterations in hydromorphology. Benthic diatom and macroinvertebrate
metrics showed high discriminatory power (R2 values often >0.50) and low error (<30%) with the primary (nutrient) gradient, while both fish and macrophyte metrics performed
relatively poorly. Conversely, both fish and macrophyte metrics showed higher response (high coefficients of determination)
than either benthic diatom or macroinvertebrate metrics to the second (e.g., alteration in habitat/hydromorphology) gradient.
However, the discriminatory power and error associated with individual metrics varied markedly, indicating that caution should
be exercised when selecting the ‘best’ organism group or metric to monitor stress. 相似文献
29.
1. International river catchments pose challenges for effective water resource management. Catchment‐wide strategies are often complicated by differences in national bioassessment and quality classification. Intercalibration efforts aim to harmonise these differences, but rely on the consistent delineation of near‐natural reference sites that are almost unavailable in today’s landscape, especially for large rivers. 2. We introduce the concept of alternative benchmarking that is based on the notion of aquatic communities at similar (low) levels of impairment associated with least‐disturbed conditions (LDC) as defined by abiotic criteria. Using data acquired during the second Joint Danube Survey, we defined LDC sites based on a multivariate gradient of anthropogenic pressures, mostly related to morphological deterioration, that spans the entire navigable Danube. 3. The river was subdivided into four stretches, each featuring homogeneous biological assemblages. Indirect gradient analysis revealed relationships between the pressure gradient and selected features of the macroinvertebrate and macrophyte community but not for diatoms or phytoplankton. 4. We identified biological metrics suitable for the quality classification of individual stretches or the entire river. Impoundment is the major hydromorphological alteration on the Danube but various metrics still responded significantly to differences in the morphological condition of sites not affected by impoundment. 5. A comparison of macroinvertebrate sampling techniques (airlift versus kick‐and‐sweep) revealed differences in how the acquired data reflect the effects of anthropogenic pressure. Biological metrics based only on kick‐and‐sweep sample data were insensitive to habitat deterioration in the heavily modified Upper Danube. 6. This study exemplifies the empirical approach of alternative benchmarking in intercalibration and offers practical solutions to some of the challenges of large river bioassessment. 相似文献
30.
Landscape pattern indices or landscape metrics, an important means in landscape pattern analysis, has resulted in the prosperity of landscape ecology. However, landscape pattern analysis was criticized recently for its poor correlation with ecological processes. In this paper, the current situation and challenges in landscape pattern analysis was elaborated, and the future of landscape pattern analysis was discussed. We believe that the landscape metrics is still the main method in spatial pattern analysis, and is important for landscape ecology. However, there are 3 challenges in landscape pattern analysis: (1) how to develop new methods by integrating explicit ecological sense in landscape pattern analysis? (2) How to link landscape pattern and ecological processes? (3) How to apply the theory of “matrix-patch-corridor” to practice? In future, 5 issues are to be addressed: (1) to develop a methodology to describe landscape pattern in a dynamic manner; (2) to explore the ecological sense of landscape pattern using a series of landscape metrics; (3) to develop new methods for landscape pattern analysis related to ecological processes; (4) to conduct landscape pattern analysis at multi-dimensions; (5) to explain the relationship between landscape pattern and ecological processes by multi-scale pattern analysis. 相似文献