In southern Florida, a vast network of canals and water control structures mediate freshwater discharge into the coastal zone. Management protocol for one such canal network (C-111) is being modified in part to try to...
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In southern Florida, a vast network of canals and water control structures mediate freshwater discharge into the coastal zone. Management protocol for one such canal network (C-111) is being modified in part to try to improve habitat for estuarine fish and wading birds in northeastern Florida Bay, an estuarine part of Everglades National Park. Changes in canal management could alter the spatial and temporal salinity regime in the estuary. To better predict the effect of such changes on estuarine habitat, abundances of submersed vegetation and benthic animals were sampled repeatedly at 12 stations that differed in salinity. A variety of other parameters were also measured (nutrients, light, temperature, oxygen, sediment characteristics, and others). Mean salinity among stations ranged from 11.4 parts per thousand to 33.1 parts per thousand. Densities of benthic plants and animals differed among stations by several orders of magnitude. The standard deviation of salinity was the best environmental correlate with mean plant biomass and benthic animal density: less biota occurred at stations with greater fluctuations in salinity. The two stations with the least plant biomass also had the highest mean water temperatures. In a stepwise multiple regression analysis, standard deviation of salinity accounted for 59% of the variation in the logarithm of mean plant biomass among stations. For every 3 parts per thousand increase in the standard deviation, total benthic plant biomass decreased by an order of magnitude. Mean water temperature accounted for only 14% of the variation, and mean salinity was not included for lack of significance. At stations with widely fluctuating salinities, not only was biomass low, but species dominance also frequently changed. Severe fluctuation in salinity may have prevented abundant benthos by causing physiological stress that reduced growth and survival. Salinity may not have remained within the range of tolerance of any one plant species for
Mobile Ad Hoc Networks are communication networks built up of a collection of mobile devices which can communicate through wireless connections. Mobile Ad Hoc Networks have many challenges such as routing, which is th...
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Ethernet-based Passive Optical Network(EPON) is considered a very promising solution for the first mile problem of the next generation *** to its particular characteristic of shared media structure,EPON suffers many s...
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Ethernet-based Passive Optical Network(EPON) is considered a very promising solution for the first mile problem of the next generation *** to its particular characteristic of shared media structure,EPON suffers many security vulnerabilities. Communication security must be guaranteed when EPON is applied in *** paper gives a general introduction to the EPON system,analyzes the potential threats and attacks pertaining to the EPON system,and presents effective countermea-sures against these threats and attacks with emphasis on the authentication protocols and key distribution.
This work is unique and contributes new knowledge to the field whereas it involves introducing a new method based on coupling two or three stochastic models, analyzing new data represented by drought and flooding risk...
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Since the 1950s, AT&T has provided underwater detection equipment to the U.S. Navy to satisfy the navy's two-tier mission of studying the ocean and developing and testing sonar systems. The latest generation o...
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Since the 1950s, AT&T has provided underwater detection equipment to the U.S. Navy to satisfy the navy's two-tier mission of studying the ocean and developing and testing sonar systems. The latest generation of hardware is a fiber-optic system that has the transmission capacity of all the previous systems combined. Its design and development has provided a challenge both from the technical aspect of meeting stringent performance requirements and from the engineering aspect of managing a large defense program having a budget greater than $500 million. Following a brief summary of AT&T's history in the development and manufacture of underwater acoustic detection hardware, this paper provides a technical description of the fiber-optic system and a project history describing the processes used in bringing the equipment into production. During the period of program execution (1989 to the present), systemsengineering management philosophy has evolved from strict now-down of requirements via military standards to concurrent engineering and product-realization teams. The Fixed Distributed System (FDS) project has followed the same route, partly by design and partly by necessity. It provided some valuable lessons that have been learned and incorporated into the present AT&T Advanced Technology systems (ATS) engineering process, which has been the basis for AT&T Best Current Practices in systemsengineering.
In the context of data mining, infrequent association rules may be beneficial for analysing rare or extreme cases with very low support values and high confidence. In researching risky situations or allocating specifi...
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作者:
Abel, Kate D.
Bachelor of Engineering in Engineering Management Program School of Systems and Enterprises United States
About a decade ago, a movement was started at Stevens Institute of Technology to infuse the Capstone experience with systemsengineering (SE) and engineering Management (EM) knowledge. However the discipline specific ...
The benefits of modularization, such as reusability and upgradeability, remain underutilized in space. Exploiting these advantages after a spacecraft is launched introduces too much cost and risk in the current paradi...
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Interdependency among critical infrastructure (CI) is an increasing phenomenon. The 21st century has been defined by events that have changed individuals' perceptions of what CI is and its risks and vulnerabilitie...
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ISBN:
(纸本)9781627482820
Interdependency among critical infrastructure (CI) is an increasing phenomenon. The 21st century has been defined by events that have changed individuals' perceptions of what CI is and its risks and vulnerabilities. One of the major critical infrastructures is the energy sector as described by public policy, and oil is an important component of this sector. This paper explores the relationships between oil and other infrastructures. We argue that the relationship between oil and other systems has changed the structure of the oil industry. How to manage this new structure is an emerging issue that requires attention from a systems approach. Whether oil is in its crude form or refined form, its value cannot be minimized due to its various applications. Oil and its derivatives are not an independent infrastructure;they are interconnected to other forms of energy and other infrastructures. These interconnections have increased risk and vulnerability from hostile nations, terrorists, criminals, and incompetent operators. We conclude that oil is critical to the well-being of humanity and yet is so fragile that it can be affected by cascading events from other critical infrastructure due coupling and pervasive computing technologies. Copyright, American Society for engineering Management, 2012.
This paper presents our response to the national need to educate more students in the area of power systemsengineering. Our Electric Energy systems Control program (EESCP) is described, both in terms of (1) individua...
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