Transgenic crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) hav... more Transgenic crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) have been grown in many parts of the world since 1996. In the United States, the Environmental Protection Agency (EPA) has required that industry submit insect resistance management (IRM) plans for each Bt corn and cotton product commercialized. A coalition of stakeholders including the EPA, USDA, academic scientists, industry, and grower organizations have cooperated in developing specific IRM strategies. Resistance monitoring (requiring submission of annual reports to the EPA), and a remedial action plan addressing any contingency if resistance should occur, are important elements of these strategies. At a global level, Monsanto conducts baseline susceptibility studies (prior to commercialization), followed by monitoring studies on target pest populations, for all of its commercialized Bt crop products. To date, Monsanto has conducted baseline/monitoring studies
EURASIP Journal on Advances in Signal Processing, 2010
... scheme does not have to transmit the palette from the embedding side to the recipient, hences... more ... scheme does not have to transmit the palette from the embedding side to the recipient, hencestrengthening secu-rity. ... In this section, we propose a Progressive Exponential Clustering-(PEC-) based steganographic scheme for hiding secret data in true colour images. ...
Dowel Bar Retrofitting (DBR) is a pavement rehabilitation technique commonly adopted to increase ... more Dowel Bar Retrofitting (DBR) is a pavement rehabilitation technique commonly adopted to increase the service life of pavements in the United States. This method involves either preventative or corrective maintenance of structural cracks or joints in jointed concrete pavement structures. The performance of DBR installations is typically measured using the Load Transfer Efficiency (LTE) parameter based on deflections. In this study, DBR was modeled using finite element analysis considering geometric, material, and support parameters. Statistical analyses were used to develop equations to predict performance of DBR in terms of stress transfer across joints or cracks. The use of stress-based load transfer provides engineers a more direct ability to determine what effect the load transfer mechanism has on reducing bending stress in the slab. This allows for proper retrofit strategies to be adopted thereby reducing fatigue mechanisms and extending the service life of rigid pavement systems.
A novel analytic framework is devised for the performance modelling of a wireless 4G cell with bu... more A novel analytic framework is devised for the performance modelling of a wireless 4G cell with bursty multiple class traffic flows consisting of Internet protocol (IP) voice calls, streaming media and data packets subject to an efficient medium access control (MAC) protocol with a buffer threshold-based traffic handling generalized partial sharing (GPS) scheme. In this context, an open queueing network
Firewalls are a well-established security mechanism to restriet the traffic exchanged between net... more Firewalls are a well-established security mechanism to restriet the traffic exchanged between networks to a certain subset of users and applications. In order to cope with new application types like multimedia applications, new firewall architectures are necessary. The performance of these new architectures is a critical factor because Quality of Service (QoS) demands of multimedia applications have tobe satisfied. We show how the performance of firewall architectures for multimedia applications can be determined. A model is presented which can be used to describe the performance of multimedia firewall architectures. This model can be used to dimension firewalls for usage with multimedia applications. In addition, we present the results of a Iab experiment, used to evaluate the performance of a distributed firewall architecture and to validate the model.
Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-... more Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-Permian mass extinction (c.251.4 Ma) within the basal Triassic Hindeodus parvus conodont zone. ETMs are distinguished from rarer, and more regional, subsequent Triassic microbialites. Large differences in ETMs between northern and southern areas of the South China Block suggest geographic provinces, and ETMs are most abundant throughout equatorial Tethys Ocean with further geographic variation. ETMs occur in shallow marine shelves in a superanoxic stratified ocean and form the only widespread Phanerozoic microbialites with structures similar to those of the Cambro-S. Kershaw et al." Earliest Triassic Microbialites…" Facies (2007) Archive Version. The original publication is available at www.springerlink.com and via DOI http://dx.doi.org/10.1007/s10347-007-0105-5 3 Ordovician, and briefly after the latest Ordovician, Late Silurian and Late Devonian extinctions. ETMs disappeared long before the mid-Triassic biotic recovery, but it is not clear why, if they are disaster taxa. In general, ETM occurrence suggests that microbially-mediated calcification occurred where upwelled carbonate-rich anoxic waters mixed with warm surface waters, forming regional dysoxia, so that extreme carbonate supersaturation and dysoxic conditions were both required for their growth. Long-term oceanic and atmospheric changes may have contributed to a trigger for ETM formation. In equatorial western Pangea the earliest microbialites are late Early Triassic, but are predicted to occur in the earliest Triassic if suitable deposits are found.
A series of hydroxyapatite/alginate (HA/Alg) nanocomposites with alginate amounts varying from 10... more A series of hydroxyapatite/alginate (HA/Alg) nanocomposites with alginate amounts varying from 10 to 40 wt% were prepared through in situ hybridization technique. The inorganic phase in the composites was carbonate-substituted HA with low crystallinity. The crystallinity of HA decreased with the increase of alginate content. HA crystallites were needle-like in shape with a typical size of 20 to 50 nm in length and 5 nm in width. FT-IR spectroscopy indicated that the chemical interaction occurred between the mineral phase and the polymer matrix. As compared to pure HA without alginate, the composites showed more homogeneous microstructures, where HA nanocrystals were well embedded in alginate matrix. Among all the samples, the composite containing 30 wt% alginate exhibited a highly ordered three-dimensional network, similar to natural bone’s microstructure.
The concept of improving building performance has, for all practical purposes, always existed at ... more The concept of improving building performance has, for all practical purposes, always existed at what might be deemed the societal level. If engineered systems do not perform as society and users deem acceptable, these systems do not continue to be constructed and are eliminated over time. The inadequate systems are replaced by improved ones whose performance is expected to be more acceptable to the stakeholders and to society. In modern times this evolution manifests itself as revisions and updates to prescriptive design codes, which typically are anywhere from one to seven years apart.
Most housing in the United States is light-frame wood construction (90% nationally, and 99% in Ca... more Most housing in the United States is light-frame wood construction (90% nationally, and 99% in California). Residential construction in the United States typically has received little or no structural engineering. The performance of wood residential construction to earthquake effects was apparent in the 1994 Northridge Earthquake, and underlines the need for new approaches to enhance building performance through improved prediction, evaluation and design methods. In this paper, methods of stochastic nonlinear dynamic analysis are used to simulate the behavior of lateral force-resisting shear wall systems typically found in residential construction subjected to earthquakes. The probability that shear wall drift limits are exceeded for uniform hazard earthquake ground motions with various return periods and intensities can be estimated from this analysis and can be related to performance levels for residential occupancy that have been suggested in concurrent research on performance-based engineering. The probability of failure under a spectrum of possible earthquakes is determined by convolving the structural fragility derived from the above analysis with the seismic hazard specified by the US Geological Survey.
A fragility analysis methodology is developed for assessing the response of light-frame wood cons... more A fragility analysis methodology is developed for assessing the response of light-frame wood construction exposed to stipulated extreme windstorms and earthquakes. Performance goals and limit states (structural and nonstructural) are identified from a review of the performance of residential construction during recent hurricanes and earthquakes in the United States. Advanced numerical modeling tools provide a computational platform for risk analysis of light-frame wood building structural systems. The analysis is demonstrated for selected common building configurations and construction (defined, e.g., by roof sheathing, truss spacing, and roof or shear wall nailing patterns). Limit state probabilities of structural systems for the performance levels identified above are developed as a function of 3-s gust wind speed (hurricanes) and spectral acceleration (earthquakes), leading to a relation between limit state probabilities and the hazard stipulated in ASCE Standard 7, "Minimum design loads for buildings and other structures."
Internet users with realistic routing configurations derived from the routing registry. We conduc... more Internet users with realistic routing configurations derived from the routing registry. We conduct a series of real-time security exercises on this routing system to study the consequence of intentionally propagating false routing information on interdomain routing and the effectiveness of corresponding defensive measures. We describe three kinds of simplistic BGP attacks in the context of security exercises designed specifically for training purposes. While an attacker can launch attacks from a compromised router by changing its routing policies, administrators will be able to observe the adverse effect of these attacks and subsequently apply appropriate defensive measures to mitigate their impact, such as installing filtering rules. These exercises, all carried out in real time, demonstrate the feasibility of largescale realistic routing experiments using the real-time routing experiment platform.
Transgenic crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) hav... more Transgenic crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) have been grown in many parts of the world since 1996. In the United States, the Environmental Protection Agency (EPA) has required that industry submit insect resistance management (IRM) plans for each Bt corn and cotton product commercialized. A coalition of stakeholders including the EPA, USDA, academic scientists, industry, and grower organizations have cooperated in developing specific IRM strategies. Resistance monitoring (requiring submission of annual reports to the EPA), and a remedial action plan addressing any contingency if resistance should occur, are important elements of these strategies. At a global level, Monsanto conducts baseline susceptibility studies (prior to commercialization), followed by monitoring studies on target pest populations, for all of its commercialized Bt crop products. To date, Monsanto has conducted baseline/monitoring studies
EURASIP Journal on Advances in Signal Processing, 2010
... scheme does not have to transmit the palette from the embedding side to the recipient, hences... more ... scheme does not have to transmit the palette from the embedding side to the recipient, hencestrengthening secu-rity. ... In this section, we propose a Progressive Exponential Clustering-(PEC-) based steganographic scheme for hiding secret data in true colour images. ...
Dowel Bar Retrofitting (DBR) is a pavement rehabilitation technique commonly adopted to increase ... more Dowel Bar Retrofitting (DBR) is a pavement rehabilitation technique commonly adopted to increase the service life of pavements in the United States. This method involves either preventative or corrective maintenance of structural cracks or joints in jointed concrete pavement structures. The performance of DBR installations is typically measured using the Load Transfer Efficiency (LTE) parameter based on deflections. In this study, DBR was modeled using finite element analysis considering geometric, material, and support parameters. Statistical analyses were used to develop equations to predict performance of DBR in terms of stress transfer across joints or cracks. The use of stress-based load transfer provides engineers a more direct ability to determine what effect the load transfer mechanism has on reducing bending stress in the slab. This allows for proper retrofit strategies to be adopted thereby reducing fatigue mechanisms and extending the service life of rigid pavement systems.
A novel analytic framework is devised for the performance modelling of a wireless 4G cell with bu... more A novel analytic framework is devised for the performance modelling of a wireless 4G cell with bursty multiple class traffic flows consisting of Internet protocol (IP) voice calls, streaming media and data packets subject to an efficient medium access control (MAC) protocol with a buffer threshold-based traffic handling generalized partial sharing (GPS) scheme. In this context, an open queueing network
Firewalls are a well-established security mechanism to restriet the traffic exchanged between net... more Firewalls are a well-established security mechanism to restriet the traffic exchanged between networks to a certain subset of users and applications. In order to cope with new application types like multimedia applications, new firewall architectures are necessary. The performance of these new architectures is a critical factor because Quality of Service (QoS) demands of multimedia applications have tobe satisfied. We show how the performance of firewall architectures for multimedia applications can be determined. A model is presented which can be used to describe the performance of multimedia firewall architectures. This model can be used to dimension firewalls for usage with multimedia applications. In addition, we present the results of a Iab experiment, used to evaluate the performance of a distributed firewall architecture and to validate the model.
Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-... more Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-Permian mass extinction (c.251.4 Ma) within the basal Triassic Hindeodus parvus conodont zone. ETMs are distinguished from rarer, and more regional, subsequent Triassic microbialites. Large differences in ETMs between northern and southern areas of the South China Block suggest geographic provinces, and ETMs are most abundant throughout equatorial Tethys Ocean with further geographic variation. ETMs occur in shallow marine shelves in a superanoxic stratified ocean and form the only widespread Phanerozoic microbialites with structures similar to those of the Cambro-S. Kershaw et al." Earliest Triassic Microbialites…" Facies (2007) Archive Version. The original publication is available at www.springerlink.com and via DOI http://dx.doi.org/10.1007/s10347-007-0105-5 3 Ordovician, and briefly after the latest Ordovician, Late Silurian and Late Devonian extinctions. ETMs disappeared long before the mid-Triassic biotic recovery, but it is not clear why, if they are disaster taxa. In general, ETM occurrence suggests that microbially-mediated calcification occurred where upwelled carbonate-rich anoxic waters mixed with warm surface waters, forming regional dysoxia, so that extreme carbonate supersaturation and dysoxic conditions were both required for their growth. Long-term oceanic and atmospheric changes may have contributed to a trigger for ETM formation. In equatorial western Pangea the earliest microbialites are late Early Triassic, but are predicted to occur in the earliest Triassic if suitable deposits are found.
A series of hydroxyapatite/alginate (HA/Alg) nanocomposites with alginate amounts varying from 10... more A series of hydroxyapatite/alginate (HA/Alg) nanocomposites with alginate amounts varying from 10 to 40 wt% were prepared through in situ hybridization technique. The inorganic phase in the composites was carbonate-substituted HA with low crystallinity. The crystallinity of HA decreased with the increase of alginate content. HA crystallites were needle-like in shape with a typical size of 20 to 50 nm in length and 5 nm in width. FT-IR spectroscopy indicated that the chemical interaction occurred between the mineral phase and the polymer matrix. As compared to pure HA without alginate, the composites showed more homogeneous microstructures, where HA nanocrystals were well embedded in alginate matrix. Among all the samples, the composite containing 30 wt% alginate exhibited a highly ordered three-dimensional network, similar to natural bone’s microstructure.
The concept of improving building performance has, for all practical purposes, always existed at ... more The concept of improving building performance has, for all practical purposes, always existed at what might be deemed the societal level. If engineered systems do not perform as society and users deem acceptable, these systems do not continue to be constructed and are eliminated over time. The inadequate systems are replaced by improved ones whose performance is expected to be more acceptable to the stakeholders and to society. In modern times this evolution manifests itself as revisions and updates to prescriptive design codes, which typically are anywhere from one to seven years apart.
Most housing in the United States is light-frame wood construction (90% nationally, and 99% in Ca... more Most housing in the United States is light-frame wood construction (90% nationally, and 99% in California). Residential construction in the United States typically has received little or no structural engineering. The performance of wood residential construction to earthquake effects was apparent in the 1994 Northridge Earthquake, and underlines the need for new approaches to enhance building performance through improved prediction, evaluation and design methods. In this paper, methods of stochastic nonlinear dynamic analysis are used to simulate the behavior of lateral force-resisting shear wall systems typically found in residential construction subjected to earthquakes. The probability that shear wall drift limits are exceeded for uniform hazard earthquake ground motions with various return periods and intensities can be estimated from this analysis and can be related to performance levels for residential occupancy that have been suggested in concurrent research on performance-based engineering. The probability of failure under a spectrum of possible earthquakes is determined by convolving the structural fragility derived from the above analysis with the seismic hazard specified by the US Geological Survey.
A fragility analysis methodology is developed for assessing the response of light-frame wood cons... more A fragility analysis methodology is developed for assessing the response of light-frame wood construction exposed to stipulated extreme windstorms and earthquakes. Performance goals and limit states (structural and nonstructural) are identified from a review of the performance of residential construction during recent hurricanes and earthquakes in the United States. Advanced numerical modeling tools provide a computational platform for risk analysis of light-frame wood building structural systems. The analysis is demonstrated for selected common building configurations and construction (defined, e.g., by roof sheathing, truss spacing, and roof or shear wall nailing patterns). Limit state probabilities of structural systems for the performance levels identified above are developed as a function of 3-s gust wind speed (hurricanes) and spectral acceleration (earthquakes), leading to a relation between limit state probabilities and the hazard stipulated in ASCE Standard 7, "Minimum design loads for buildings and other structures."
Internet users with realistic routing configurations derived from the routing registry. We conduc... more Internet users with realistic routing configurations derived from the routing registry. We conduct a series of real-time security exercises on this routing system to study the consequence of intentionally propagating false routing information on interdomain routing and the effectiveness of corresponding defensive measures. We describe three kinds of simplistic BGP attacks in the context of security exercises designed specifically for training purposes. While an attacker can launch attacks from a compromised router by changing its routing policies, administrators will be able to observe the adverse effect of these attacks and subsequently apply appropriate defensive measures to mitigate their impact, such as installing filtering rules. These exercises, all carried out in real time, demonstrate the feasibility of largescale realistic routing experiments using the real-time routing experiment platform.
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