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Articles 3151 - 3180 of 3345
Full-Text Articles in Physical Sciences and Mathematics
Late-Holocene Climate And Ecosystem History From Chesapeake Bay Sediment Cores, Usa, Debra A. Willard, Thomas M. Cronin, Stacey Verardo
Late-Holocene Climate And Ecosystem History From Chesapeake Bay Sediment Cores, Usa, Debra A. Willard, Thomas M. Cronin, Stacey Verardo
United States Geological Survey: Staff Publications
Palaeoclimate records from late-Holocene sediments in Chesapeake Bay, the largest estuary in the USA, provide evidence that both decadal to centennial climate variability and European colonization had severe impacts on the watershed and estuary. Using pollen and dinoflagellate cysts as proxies for mid-Atlantic regional precipitation, estuarine salinity and dissolved oxygen (DO) during the last 2300 years, we identified four dry intervals, centred on ad 50 (P1/D1), ad 1000 (P2/D2), ad 1400 (P3) and ad 1600 (P4). Two centennial-scale events, P1/D1 and P2/D2, altered forest composition and led to increased salinity and DO levels in the estuary. Intervals P3 and P4 …
Digitization In An Archival Environment, Sally Mckay
Digitization In An Archival Environment, Sally Mckay
E-JASL: Electronic Journal of Academic and Special Librarianship (1999-2009, Volumes 1-10)
Introduction
Cultural institutions such as museums, libraries, archives, and historical societies house remarkable collections of cultural artifacts. It is the responsibility of the staff working for those institutions to preserve, protect and provide responsible stewardship for the materials, and to the best of their ability, provide continued long-term access (Russell, 2000).
Advances in technology allow institutions to provide expanded access and education; however, there are important priorities that must be addressed prior to embarking on a digital conversion project.
Digitization in an archival environment includes taking a physical object or analog item, such as an art object, a tape recording, …
Apparent Break In Earthquake Scaling Due To Path And Site Effects On Deep Borehole Recordings, Satoshi Ide, Gregory C. Beroza, Stephanie G. Prejean, William L. Ellsworth
Apparent Break In Earthquake Scaling Due To Path And Site Effects On Deep Borehole Recordings, Satoshi Ide, Gregory C. Beroza, Stephanie G. Prejean, William L. Ellsworth
United States Geological Survey: Staff Publications
We reexamine the scaling of stress drop and apparent stress, rigidity times the ratio between seismically radiated energy to seismic moment, with earthquake size for a set of microearthquakes recorded in a deep borehole in Long Valley, California. In the first set of calculations, we assume a constant Q and solve for the corner frequency and seismic moment. In the second set of calculations, we model the spectral ratio of nearby events to determine the same quantities. We find that the spectral ratio technique, which can account for path and site effects or nonconstant Q, yields higher stress drops, …
Topographically Driven Groundwater Flow And The San Andreas Heat Flow Paradox Revisited, Demian M. Saffer, Barbara A. Bekins, Stephen Hickman
Topographically Driven Groundwater Flow And The San Andreas Heat Flow Paradox Revisited, Demian M. Saffer, Barbara A. Bekins, Stephen Hickman
United States Geological Survey: Staff Publications
Evidence for a weak San Andreas Fault includes borehole heat flow measurements that show no evidence for a frictionally generated heat flow anomaly and the inferred orientation of σ1 nearly perpendicular to the fault trace. Interpretations of the stress orientation data remain controversial, at least in close proximity to the fault, leading some researchers to hypothesize that the San Andreas Fault is, in fact, strong and that its thermal signature may be removed or redistributed by topographically driven groundwater flow in areas of rugged topography, such as typify the San Andreas Fault system. To evaluate this scenario, we use …
Stratigraphy, Geochronology, And Accretionary Terrane Settings Of Two Bronson Hill Arc Sequences, Northern New England, Robert H. Moench, John N. Aleinikoff
Stratigraphy, Geochronology, And Accretionary Terrane Settings Of Two Bronson Hill Arc Sequences, Northern New England, Robert H. Moench, John N. Aleinikoff
United States Geological Survey: Staff Publications
The Ammonoosuc Volcanics, Partridge Formation, and the Oliverian and Highlandcroft Plutonic Suites of the Bronson Hill anticlinorium (BHA) in axial New England are widely accepted as a single Middle to Late Ordovician magmatic arc that was active during closure of Iapetus. Mapping and U–Pb dating indicate, however, that the BHAcontains two volcano-sedimentary-intrusive sequences of probable opposite subduction polarity, here termed the Ammonoosuc and Quimby sequences.
The Ammonoosuc sequence is defined by the Middle Ordovician Ammonoosuc Volcanics near Littleton, NH, the type area, northeast to Milan, NH, and Oquossoc, ME; it also includes black slate of the Partridge Formation (C.bicornis …
Differences In Habitat Use By Blanding’S Turtles, Emydoidea Blandingii, And Painted Turtles, Chysemys Picta, In The Nebraska Sandhills, R. Bruce Bury, David J. Germano
Differences In Habitat Use By Blanding’S Turtles, Emydoidea Blandingii, And Painted Turtles, Chysemys Picta, In The Nebraska Sandhills, R. Bruce Bury, David J. Germano
United States Geological Survey: Staff Publications
We sampled a variety of wetlands in the Nebraska sandhills at Valentine National Wildlife Refuge. Significantly more individuals of painted turtles (Chrysemys picta) occurred in lakes and open waters than in marshes or small ponds, and the opposite was true for Blanding’s turtles (Emydoidea blandingii). Besides this marked difference in habitat use, 46% of the captured E. blandingii in pond/marsh habitat were juveniles, but only 31.6% in lakes and open water. Current information suggests that marshes and small ponds are important habitat for juvenile turtles, especially Emydoidea blandingii.
Monitoring Trends In Bat Populations Of The United States And Territories: Status Of The Science And Recommendations For The Future, Thomas J. O'Shea, Michael A. Bogan, Laura E. Ellison
Monitoring Trends In Bat Populations Of The United States And Territories: Status Of The Science And Recommendations For The Future, Thomas J. O'Shea, Michael A. Bogan, Laura E. Ellison
United States Geological Survey: Staff Publications
Populations of bats (Order Chiroptera) are difficult to monitor. However, current recognition of the importance of bats to biodiversity, their ecological and economic value as ecosystem components, and their vulnerability to declines makes monitoring trends in their populations a much-needed cornerstone for their future management. We report findings and recommendations of a recent expert workshop on monitoring trends in bat populations in the United States and territories. We summarize selected case reports presented by others at the workshop, including reviews of methods and ongoing efforts to monitor a wide range of species of bats in a diverse array of situations. …
Public Knowledge And Perceptions Of Black-Tailed Prairie Dogs, Berton Lee Lamb, Kurt Cline
Public Knowledge And Perceptions Of Black-Tailed Prairie Dogs, Berton Lee Lamb, Kurt Cline
United States Geological Survey: Staff Publications
Black-tailed prairie dogs (Cynomys ludovicianus) historically occupied an 11-state region of the United States. We surveyed 1,900 residents (response rate 56%) of this region to understand citizen knowledge and perceptions about prairie dogs and their management. Those who have direct experience— e.g., those who live very close to prairie dog colonies or know the location of the nearest colony—have higher levels of knowledge. A significantly higher level of knowledge was documented among those who were politically active when compared with the general public. Those who found environmental issues difficult to understand were associated with lower knowledge. People with …
Last Glacial Loess In The Conterminous Usa, E. Arthur Bettis Iii, Daniel R. Muhs, Helen M. Roberts, Ann G. Wintle
Last Glacial Loess In The Conterminous Usa, E. Arthur Bettis Iii, Daniel R. Muhs, Helen M. Roberts, Ann G. Wintle
United States Geological Survey: Staff Publications
The conterminous United States contains an extensive and generally well-studied record of Last Glacial loess. The loess occurs in diverse physiographic provinces, and under a wide range of climatic and ecological conditions. Both glacial and non-glacial loess sources are present, and many properties of the loess vary systematically with distance from loess sources. United States’ mid-continent Last Glacial loess is probably the thickest in the world, and our calculated mass accumulation rates (MARs) are as high as 17,500 g/m2/yr at the Bignell Hill locality in Nebraska, and many near-source localities have MARs greater than 1500 g/m2/yr. …
Evolution From A Conventional Well Field To A Riverbank-Filtration System, John D. North, Douglas J. Schnoebelen, Shelli Grapp, Roy E. Hesemann
Evolution From A Conventional Well Field To A Riverbank-Filtration System, John D. North, Douglas J. Schnoebelen, Shelli Grapp, Roy E. Hesemann
United States Geological Survey: Staff Publications
The City of Cedar Rapids is located in east-central Iowa and has a population of 121,000. The Cedar River alluvial aquifer is the sole source of drinking water for the City. Within the last few years, the Cedar River — which drains a major agricultural watershed — has experienced extended periods of elevated levels of nitrate and herbicides (notably, atrazine and its degradation byproducts) that were above the maximum contaminant level for drinking water. Fortunately, during these extended periods of compromised water quality in the river, RBF enabled the Cedar Rapids Water Department to obtain and treat adequate quantities of …
Ethylenediaminetetraacetic Acid Occurrence And Removal Through Bank Filtration In The Platte River, Nebraska, Jason R. Vogel, Larry B. Barber, Tyler B. Coplen, Ingrid M. Verstraeten, Thomas F. Speth, Jerry Obrist, Win Butler
Ethylenediaminetetraacetic Acid Occurrence And Removal Through Bank Filtration In The Platte River, Nebraska, Jason R. Vogel, Larry B. Barber, Tyler B. Coplen, Ingrid M. Verstraeten, Thomas F. Speth, Jerry Obrist, Win Butler
United States Geological Survey: Staff Publications
The USGS, USEPA, and City of Lincoln Water System (Nebraska) have conducted a study to determine the occurrence and removal of EDTA, NTA, and nonylphenol monoethoxycarboxylate to nonylphenol pentaethoxycarboxylate (NP1EC-NP5EC) in the hydrologic system at the City of Lincoln well field. The objective of the study is to evaluate the occurrence and removal of EDTA, NTA, and total nonylphenolpolyethoxycarboxylate (NPEC) by bank filtration at the City of Lincoln well field. This presentation will discuss removal during two sampling periods — May and August 2002 — based upon surface-water fractions in the collector well calculated using stable isotope ratios of hydrogen …
An Experimental And Theoretical Study Of Transient Negative Ions In Mg, Zn, Cd And Hg, J. P. Sullivan, Paul Burrow, D. S. Newman, K. Bartschat, J. A. Michejda, P. Panajotovic, M. Moghbelalhossein, R. P. Mceachran, Stephen J. Busckman
An Experimental And Theoretical Study Of Transient Negative Ions In Mg, Zn, Cd And Hg, J. P. Sullivan, Paul Burrow, D. S. Newman, K. Bartschat, J. A. Michejda, P. Panajotovic, M. Moghbelalhossein, R. P. Mceachran, Stephen J. Busckman
Paul Burrow Publications
A range of experimental and theoretical techniques have been applied to the study of transient negative ions (resonances) formed in electron scattering from the Group II metals Mg, Zn, Cd, and Hg at incident electron energies below the first ionization potential. A wealth of resonance structures have been observed and from the experimental observations and theoretical information, classifications are proposed for some of these negative ion states.
Homogeneous Weights And Exponential Sums, José Felipe Voloch, Judy L. Walker
Homogeneous Weights And Exponential Sums, José Felipe Voloch, Judy L. Walker
Department of Mathematics: Faculty Publications
In this paper, we give a formula as an exponential sum for a homogeneous weight defined by Constantinescu and Heise [3] in the case of Galois rings (or equivalently, rings of Witt vectors) and use this formula to estimate the weight of codes obtained from algebraic geometric codes over rings.
Intercontinental Migration Of Large Mammalian Carnivores: Earliest Occurrence Of The Old World Beardog Amphicyon (Carnivora, Amphicyonidae) In North America, Robert M. Hunt Jr.
Intercontinental Migration Of Large Mammalian Carnivores: Earliest Occurrence Of The Old World Beardog Amphicyon (Carnivora, Amphicyonidae) In North America, Robert M. Hunt Jr.
Department of Earth and Atmospheric Sciences: Faculty Publications
North American amphicyonid carnivorans are prominent members of the mid-Cenozoic terrestrial carnivore community during the late Eocene to late Miocene (Duchesnean to Clarendonian). Species range in size from <5 kg to >200 kg. Among the largest amphicyonids are Old and New World species of the genus Amphicyon: A. giganteus in Europe (18–~15? Ma) and Africa, A. ingens in North America (15.9–~14.2 Ma). Amphicyon first appears in the Oligocene of western Europe, surviving there until the late Miocene. Migration to Africa and North America takes place in the early Miocene. The genus occurs in the Arrisdrift fauna (Namibia) of southwest Africa, indicating migration south …5>
A Daily Soil Temperature Dataset And Soil Temperature Climatology Of The Contiguous United States, Q. Steven Hu, Yongjun Zheng
A Daily Soil Temperature Dataset And Soil Temperature Climatology Of The Contiguous United States, Q. Steven Hu, Yongjun Zheng
Department of Earth and Atmospheric Sciences: Faculty Publications
Although affected by atmospheric circulations, variations in soil temperature result primarily from the radiation and sensible and latent heat exchanges at the surface and heat transfer in the soils of different thermal properties. Thus, soil temperature and its variation at various depths are unique parameters that are useful in understanding both the surface energy processes and regional environmental and climatic conditions. Yet, despite the importance, long-term quality data of soil temperatures are not available for the United States. The goal of this study is to fill this data gap and to develop a soil temperature dataset from the historical data …
Chemical Repellents For Reducing Crop Damage By Blackbirds, Michael L. Avery, John L. Cummings
Chemical Repellents For Reducing Crop Damage By Blackbirds, Michael L. Avery, John L. Cummings
United States Department of Agriculture Wildlife Services: Staff Publications
Chemical repellants are intended to prevent birds from feeding on a particular food (the crop) at a given location. To be considered effective, a chemical repellent must produce 1 of 2 responses (1) depredating birds remain but feed on an alternative non-crop food item or (2) depredating birds leavc and go elsewhere to feed. The search for a safe, cost-effective chemical repellent has spanned decades. During the 1950s, 196Os, and 199Os, repellent screening programs, using captive red-winged blackbirds (Aaelaius Dboeniceus), brown-headed cowbirds (Molorhrus ater), and European starlings (Sturnus vulgaris), identified numerous potentially useful compounds. …
Wading Bird Management And Research On North American Aquaculture Facilities, Brian Dorr, Jimmy D. Taylor Ii
Wading Bird Management And Research On North American Aquaculture Facilities, Brian Dorr, Jimmy D. Taylor Ii
United States Department of Agriculture Wildlife Services: Staff Publications
Aquaculture in North America varies geographically with respect to species cultured, annual production, size, complexity, and spatial arrangement of facilities. Species assemblages of predacious birds using aquaculture facilities also vary with many of these industry characteristics. Wading birds are highly adaptable, relatively ubiquitous throughout the aquaculture industry, and often associated with fish depredation problems at aquaculture facilities. Suitability of information regarding the impacts of wading birds to aquaculture varies dramatically by depredating species and industry sector. Great blue herons (Ardea herodias) cause considerable depredation losses on trout aquaculture in the Northeast, and current research suggests that little blue …
Training Deer To Avoid Sites Through Negative Reinforcement, Dale L. Nolte, Kurt C. Vercauteren, Kelly R. Perry, Suzanne E. Adams
Training Deer To Avoid Sites Through Negative Reinforcement, Dale L. Nolte, Kurt C. Vercauteren, Kelly R. Perry, Suzanne E. Adams
United States Department of Agriculture Wildlife Services: Staff Publications
Deer frequently visit areas where they may cause damage. Incidents along roadways and runways inflict numerous injuries to animals and humans, and cause considerable economic losses. Concerns are increasing that deer interactions with domestic animals may contribute to spread of disease. Deer foraging in residential areas, agricultural fields, or plant propagation sites can impede growth and possibly survival of desirable plants. We conducted a series of trials to determine whether mild electric shock would induce place avoidance in deer. Shock was delivered through a device attached to a collar. A noise cue was emitted as an animal approached a defined …
The Influence Of Predator Odours And Overcrowded Mouse Odours On Regulation Of Oestrous Cycles In House Mice (Mus Musculus), Natalia Yu. Severtzov, Svetlana V. Naidenko, Anna E. Voznesenskaia, Georgy J. Krivomazov, Larry Clark, Vera V. Voznessenskaya
The Influence Of Predator Odours And Overcrowded Mouse Odours On Regulation Of Oestrous Cycles In House Mice (Mus Musculus), Natalia Yu. Severtzov, Svetlana V. Naidenko, Anna E. Voznesenskaia, Georgy J. Krivomazov, Larry Clark, Vera V. Voznessenskaya
United States Department of Agriculture Wildlife Services: Staff Publications
We investigated the influence of chemical signals derived from different sources—urine of feral cats (Felis catus) and urine from overcrowded mice (Mus musculus) on regulation of oestrous cycles in Mus musculus musculus under laboratory conditions. Cat urine and urine from mice housed in overcrowded conditions caused very similar effects. Application of urine from feral cats and from overcrowded conspecifics to the bedding of experimental animals for a period of 21 days caused a significant increase in numbers of animals with extended oestrous cycles. Application of cat urine or overcrowded mouse urine to the bedding of female …
Double-Crested Cormorant Impacts To Commercial And Natural Resources, Jimmy D. Taylor Ii, Brian S. Dorr
Double-Crested Cormorant Impacts To Commercial And Natural Resources, Jimmy D. Taylor Ii, Brian S. Dorr
United States Department of Agriculture Wildlife Services: Staff Publications
The North American population of double-crested cormorants (Phalacrocorax auritus) has increased at an annual rate of 6.8% since 1966, with regional growth exceeding 20%/year since 1990 in Ontario and states bordering the Great Lakes. Population numbers, though operating under biological carrying capacity, have exceeded acceptance capacity with several wildlife stakeholder groups throughout Canada and the United States. Stakeholder concerns predominantly focus around social, ecological, and economic values associated with habitat destruction, changes in recreational fisheries, and loss of production at aquaculture facilities. We describe perceptible impacts to these commercial and natural resources, and discuss current research and management …
Characteristics Of Mountain Lion Bed, Cache And Kill Sites In Northeastern Oregon, James J. Akenson, M. Cathy Nowak, Mark G. Henjum, Gary W. Witmer
Characteristics Of Mountain Lion Bed, Cache And Kill Sites In Northeastern Oregon, James J. Akenson, M. Cathy Nowak, Mark G. Henjum, Gary W. Witmer
United States Department of Agriculture Wildlife Services: Staff Publications
We described mountain lion (Puma concolor) habitat characteristics during two studies in the same area of northeastern Oregon during the 1990s. In the first study (1992-1994) we evaluated micro-habitat features associated with 61 diurnal bed sites that were not associated with kills. We used similar techniques in the second study (1996- 1998) to evaluate habitat features at 79 cache sites near lion-killed prey. A dog was used to find 93% of the diurnal bed sites. Radio telemetry triangulation was used in the second study. Characteristics of diurnal bed sites and cache sites were compared with random habitat plots. …
Status Of Double-Crested Cormorant Phalacrocorax Auritus Research And Management In North America, Scott J. Werner, Shauna L. Hanisch
Status Of Double-Crested Cormorant Phalacrocorax Auritus Research And Management In North America, Scott J. Werner, Shauna L. Hanisch
United States Department of Agriculture Wildlife Services: Staff Publications
The Double-crested Cormorant, the most abundant of North America’s six cormorant species, has rebounded to high numbers after new extirpation in the 1960s and early 1970s. Enhanced environmental regulations and the availability of prey fishes facilitated the resurgence of Double-crested Cormorant populations by the mid-1970s and numbers have continued to increase steadily in most geographic regions through the present. The North American population of Double-crested Cormorants has been estimated at one to two million birds. Concerns about impacts of Double-crested Cormorants on aquacultural stock, sport fish populations, other birds, vegetation, private property, and local economies have been raised. Economic impacts …
Sulfate Oxygen-17 Anomaly In An Oligocene Ash Bed In Mid-North America: Was It The Dry Fogs?, Huiming Bao, Mark H. Thiemens, David B. Loope, Xun-Lai Yuan
Sulfate Oxygen-17 Anomaly In An Oligocene Ash Bed In Mid-North America: Was It The Dry Fogs?, Huiming Bao, Mark H. Thiemens, David B. Loope, Xun-Lai Yuan
Department of Earth and Atmospheric Sciences: Faculty Publications
The oxygen and sulfur isotope compositions of sulfate, particularly the oxygen-17 anomaly, provide clues to the origin of sulfate. We report a variable oxygen-17 anomaly for water- and acid-leached sulfate from an Oligocene volcanic ash bed in the northern High Plains, U.S.A. We find no sulfate O-17 anomaly, however, in freshly collected ashes from recent eruptions around the world. The Oligocene paleoclimatic and sedimentary evidence argues against a hyperarid condition in the High Plains, thus a long-term background atmospheric sulfate accumulation is less likely the origin. Combining sulfur isotope data, we suggest that the anomalous sulfate was associated with volcanic …
Pliocene Summer Sea Surface Temperature Reconstruction Using Silicoflagellates From Southern Ocean Odp Site 1165, Jason M. Whitehead, Steven M. Bohaty
Pliocene Summer Sea Surface Temperature Reconstruction Using Silicoflagellates From Southern Ocean Odp Site 1165, Jason M. Whitehead, Steven M. Bohaty
Department of Earth and Atmospheric Sciences: Faculty Publications
In the modern marine environment the silicoflagellate genus Dictyocha is rare, or absent, south of the Antarctic polar front (APF); the genus Distephanus, in contrast, is dominant. In sediments recovered from ODP Site 1165, 1600 km south of the front, however, three intervals where Dictyocha is abundant are interpreted to represent Pliocene warm events. Comparison of our data with Ciesielski and Weaver’s [1974] modern core top silicoflagellate relationship with sea surface temperature (SST) indicates that at Site 1165 mean annual SST was approximately 5C at 3.7 Ma (event I), and approximately 4C at 4.3–4.4 Ma (event II) and 4.55–4.8 …
Teaching A Multiagent Systems Class With Game Days: Designs And Lessons Learned, Leen-Kiat Soh
Teaching A Multiagent Systems Class With Game Days: Designs And Lessons Learned, Leen-Kiat Soh
School of Computing: Technical Reports
In the Fall semester of 2002, I introduced and taught a class in Multiagent Systems. The class was aimed for seniors (with special permission) and graduate students in Computer Science, covering some breadth and depth of issues in multiagent systems. One of the requirements was participation in four Game Days. On each Game Day, student teams competed against each other in games related to issues such as auction, task allocation, coalition formation, and negotiation. This article documents my designs of and lessons learned from these Game Days. The Game Days were very successful. Through role-playing, the students were motivated and …
Inter-Domain Dynamic Routing In Multi-Layer Optical Transport Networks, Xi Yang, Byrav Ramamurthy
Inter-Domain Dynamic Routing In Multi-Layer Optical Transport Networks, Xi Yang, Byrav Ramamurthy
School of Computing: Conference and Workshop Papers
Next-generation optical transport networks will automatically and dynamically provision end-to-end connections. In this paper, we study the problem of inter-domain dynamic routing under a multi-layer multi-domain network model, which allows the end-to-end connections to be set up not only across multiple routing domains but also through two transport layers: the optical layer and the digital layer. In this model, a connection can traverse the domain boundary either through optical bypass or through optical-electrical-optical (O/E/O) processing. We propose an inter-domain dynamic routing scheme with modest time complexity to address the problem from an algorithmic perspective.
Learning Monotone Dnf Using Spp Teaching Assistant, N. V. Vinodchandran
Learning Monotone Dnf Using Spp Teaching Assistant, N. V. Vinodchandran
School of Computing: Technical Reports
In this paper we prove a new upper bound on learning monotone DNF formulae in an exact learning model called the teaching assistant model. This model, introduced in one of our earlier works, uses teaching assistant classes for classifying the complexity of learning problems. Teaching assistant classes are a learning-theoretic analog of complexity classes. We show that monotone DNF are learnable using a teaching assistant in the class SPP. On the other hand, concept classes such as k-CNF or Boolean circuits are not learnable using an SPP teaching assistant unless Np SPP. We also observe that the recent SPP algorithm …
A Novel Fiber Delay Line Buffering Architecture For Optical Packet Switching, Lin Li, Stephen Scott, Jitender S. Deogun
A Novel Fiber Delay Line Buffering Architecture For Optical Packet Switching, Lin Li, Stephen Scott, Jitender S. Deogun
School of Computing: Conference and Workshop Papers
Due to the lack of optical random access memory, optical fiber delay line (FDL) is currently the only way to implement optical buffering. Feed-forward and feedback are two kinds of FDL structures in optical buffering. Both have advantages and disadvantages. In this paper, we propose a more effective hybrid FDL architecture that combines the merits of both schemes. The core of this switch is the arrayed waveguide grating (AWG) and the tunable wavelength converter (TWC). It requires smaller optical device sizes and fewer wavelengths and has less noise than feedback architecture. At the same time, it can facilitate preemptive priority …
A New Efficient Algorithm For Solving The Simple Temporal Problem, Lin Xu, Berthe Y. Choueiry
A New Efficient Algorithm For Solving The Simple Temporal Problem, Lin Xu, Berthe Y. Choueiry
School of Computing: Conference and Workshop Papers
Motivation for Simple Temporal Problem (STP)
STP - TCSP - DTP
Consistency properties & algorithms
General CSPs
STP
Contributions
Use (improved) PPC for STP
Refine it into ΔSTP
Evaluation on random instances, 3 generators
Summary & new results
A New Efficient Algorithm For Solving The Simple Temporal Problem, Lin Xu, Berthe Y. Choueiry
A New Efficient Algorithm For Solving The Simple Temporal Problem, Lin Xu, Berthe Y. Choueiry
School of Computing: Conference and Workshop Papers
In this paper we propose a new efficient algorithm, the Δ STP-solver, for computing the minimal network of the Simple Temporal Problem (STP). This algorithm achieves high performance by exploiting a topological property of the constraint graph (i.e., triangulation) and a semantic property of the constraints (i.e., convexity) in light of the results reported by Bliek and Sam-Haroud [1], which were presented for general CSPs and have not yet been applied to temporal networks. Importantly, we design the constraint propagation in Δ STP-solver to operate on triangles instead of operating on edges and implicitly guarantee the decomposition of …