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101.
Ute C. Herzfeld Bruce F. Wallin Carlton J. LeuschenJoel Plummer 《Computers & Geosciences》2011,37(11):1793-1801
The objective of this paper is to derive an algorithm for preserving important subscale morphologic characteristics at grids of lower-resolution, in particular for linear features such as canyons and ridge lines. The development of such an algorithm is necessitated by applications that require reduced spatial resolution, as is common in cartographic generalization, GIS applications, and geophysical modeling. Since any algorithm that results in weighted averages, including optimum interpolation and ordinary kriging, cannot reproduce correct depths, a new algorithm is designed based on principles of mathematical morphology. The algorithm described here is applied to derive a subglacial bed of the Greenland Ice Sheet that includes the trough of Jakobshavn Isbræ as a continuous canyon at correct depth in a low-resolution (5-km) digital elevation model (DEM). Data from recent airborne radar measurements of the elevation of the subglacial bed as part of the CReSIS project are utilized. The morphologic algorithm is designed with geophysical ice-sheet modeling in mind, in the following context. Currently occurring changes in the Earth's climate and the cryosphere cause changes in sea level, and the societal relevance of these natural processes motivates estimation of maximal sea-level rise in the medium-term future. The fast-moving outlet glaciers are more sensitive to climatic change than other parts of the Greenland ice sheet. Jakobshavn Isbrae, the fastest-moving ice stream in Greenland, follows a subglacial geologic trough. Since the existence of the trough causes the acceleration of the slow-moving inland ice in the Jakobshavn region and the formation of the ice stream, correct representation of the trough in a DEM is essential to model changes in the dynamics of the ice sheet and resultant sea-level predictions, even if current ice-sheet models can typically be run only at 5-km resolution. The DEM resultant from this study helps to bridge the conceptual gap between data analysis and geophysical modeling approaches. It is available as SeaRISE Greenland bed data set dev1.2 at http://websrv.cs.umt.edu/isis/index.php/SeaRISE_Assessment. 相似文献
102.
Consider the robust network design problem of finding a minimum cost network with enough capacity to route all traffic demand
matrices in a given polytope. We investigate the impact of different routing models in this robust setting: in particular,
we compare oblivious routing, where the routing between each terminal pair must be fixed in advance, to dynamic routing, where routings may depend arbitrarily on the current demand. Our main result is a construction that shows that the
optimal cost of such a network based on oblivious routing (fractional or integral) may be a factor of Ω(log n) more than the cost required when using dynamic routing. This is true even in the important special case of the asymmetric
hose model. This answers a question in (Chekuri, SIGACT News 38(3):106–128, 2007), and is tight up to constant factors. Our proof technique builds on a connection between expander graphs and robust design
for single-sink traffic patterns (Chekuri et al., Networks 50(1):50–54, 2007). 相似文献
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Akila Varadarajan Nilesh Patel Bruce Maxim William I. Grosky 《Multimedia Tools and Applications》2008,40(2):211-239
There has been increased interest on the impact of mobile devices such as PDAs and Tablet PCs in introducing new pedagogical
approaches and active learning experiences. We propose an intelligent system that efficiently addresses the inherent subjectivity
in student perception of note taking and information retrieval. We employ the idea of cross indexing the digital ink notes
with matching electronic documents in the repository. Latent Semantic Indexing is used to perform document and page level
indexing. Thus for each retrieved document, the user can go over to the relevant pages that match the query. Techniques to
handle problems such as polysemy (multiple meanings of a word) in large databases, document folding and no match for query
are discussed. We tested our system for its performance, usability and effectiveness in the learning process. The results
from the exploratory studies reveal that the proposed system provides a highly enhanced student learning experience, thereby
facilitating high test scores.
Akila Varadarajan is a Senior Software Engineer at Motorola, IL with the Mobile devices division. Prior joining Motorola, she was a Software development intern at Autodesk, MI and Graduate Research assistant at University of Michigan - Dearborn. She received her MS in Computer Engineering from University of Michigan in 2006 and her BS in Computer Engineering from Madurai Kamaraj University, India in 2003. She is interested in Mobile computing - specifically Human Factors of Mobile Computing, Information retrieval and pattern recognition. Nilesh Patel is Assistant Professor in the department of Computer Science and Engineering at Oakland University, MI. He received his PhD and MS in Computer Science from Wayne State University, MI in 1997 and 1993. He is interested in Multimedia Information Processing - specifically audio and video indexing, retrieval and event detection, Pattern Recognition, Distributed Data Mining in a heterogeneous environment, and Computer Vision with special interest in medical imaging. Dr. Patel has also served in the automotive sector for several years and developed interest in Telematics and Mobile Computing. Bruce Maxim has worked as a software engineer for the past 31 years. He is a member of the Computer and Information Science faculty at the University of Michigan-Dearborn since 1985. He serves as the computing laboratory supervisor and head of the undergraduate programs in Computer Science, Software Engineering, and Information Systems. He has created more than 15 Computer and Information Science courses dealing with software engineering, game design, artificial intelligence, user interface design, web engineering, software quality, and computer programming. He has authored or co-authored four books on programming and software engineering. He has most recently served on the pedagogy subcommittee for Software Engineering 2004 and contributed to the IDGA Game Curriculum Framework 2008 guidelines. William I. Grosky is currently Professor and Chair of the Department of Computer and Information Science at University of Michigan - Dearborn, Dearborn, Michigan. Prior to joining the University of Michigan in 2001, he was Professor and Chair of the Department of Computer Science at Wayne State University, Detroit, Michigan. Before joining Wayne State University in 1976, he was an Assistant Professor in the Department of Information and Computer Science at Georgia Tech, Atlanta, Georgia. He received his B.S. in Mathematics from MIT in 1965, his M.S. in Applied Mathematics from Brown University in 1968, and his Ph.D. in Engineering and Applied Science from Yale University in 1971. 相似文献
William I. GroskyEmail: |
Akila Varadarajan is a Senior Software Engineer at Motorola, IL with the Mobile devices division. Prior joining Motorola, she was a Software development intern at Autodesk, MI and Graduate Research assistant at University of Michigan - Dearborn. She received her MS in Computer Engineering from University of Michigan in 2006 and her BS in Computer Engineering from Madurai Kamaraj University, India in 2003. She is interested in Mobile computing - specifically Human Factors of Mobile Computing, Information retrieval and pattern recognition. Nilesh Patel is Assistant Professor in the department of Computer Science and Engineering at Oakland University, MI. He received his PhD and MS in Computer Science from Wayne State University, MI in 1997 and 1993. He is interested in Multimedia Information Processing - specifically audio and video indexing, retrieval and event detection, Pattern Recognition, Distributed Data Mining in a heterogeneous environment, and Computer Vision with special interest in medical imaging. Dr. Patel has also served in the automotive sector for several years and developed interest in Telematics and Mobile Computing. Bruce Maxim has worked as a software engineer for the past 31 years. He is a member of the Computer and Information Science faculty at the University of Michigan-Dearborn since 1985. He serves as the computing laboratory supervisor and head of the undergraduate programs in Computer Science, Software Engineering, and Information Systems. He has created more than 15 Computer and Information Science courses dealing with software engineering, game design, artificial intelligence, user interface design, web engineering, software quality, and computer programming. He has authored or co-authored four books on programming and software engineering. He has most recently served on the pedagogy subcommittee for Software Engineering 2004 and contributed to the IDGA Game Curriculum Framework 2008 guidelines. William I. Grosky is currently Professor and Chair of the Department of Computer and Information Science at University of Michigan - Dearborn, Dearborn, Michigan. Prior to joining the University of Michigan in 2001, he was Professor and Chair of the Department of Computer Science at Wayne State University, Detroit, Michigan. Before joining Wayne State University in 1976, he was an Assistant Professor in the Department of Information and Computer Science at Georgia Tech, Atlanta, Georgia. He received his B.S. in Mathematics from MIT in 1965, his M.S. in Applied Mathematics from Brown University in 1968, and his Ph.D. in Engineering and Applied Science from Yale University in 1971. 相似文献
108.
The effectiveness of intermittent, microclimate cooling for men who worked in US Army chemical protective clothing (modified mission-oriented protective posture level 3; MOPP 3) was examined. The hypothesis was that intermittent cooling on a 2 min on-off schedule using a liquid cooling garment (LCG) covering 72% of the body surface area would reduce heat strain comparably to constant cooling. Four male subjects completed three experiments at 30 degrees C, 30% relative humidity wearing the LCG under the MOPP 3 during 80 min of treadmill walking at 224 +/- 5 W . m(-2). Water temperature to the LCG was held constant at 21 degrees C. The experiments were; 1) constant cooling (CC); 2) intermittent cooling at 2-min intervals (IC); 3) no cooling (NC). Core temperature increased (1.6 +/- 0.2 degrees C) in NC, which was greater than IC (0.5 +/- 0.2 degrees C) and CC (0.5 +/- 0.3 degrees C) ( p < 0.05). Mean skin temperature was higher during NC (36.1 +/- 0.4 degrees C) than IC (33.7 +/- 0.6 degrees C) and CC (32.6 +/- 0.6 degrees C) and mean skin temperature was higher during IC than CC ( p < 0.05). Mean heart rate during NC (139 +/- 9 b . min(-1)) was greater than IC (110 +/- 10 b . min(-1)) and CC (107 +/- 9 b . min(-1)) ( p < 0.05). Cooling by conduction (K) during NC (94 +/- 4 W . m(-2)) was lower than IC (142 +/- 7 W . m(-2)) and CC (146 +/- 4 W . m(-2)) ( p < 0.05). These findings suggest that IC provided a favourable skin to LCG gradient for heat dissipation by conduction and reduced heat strain comparable to CC during exercise-heat stress in chemical protective clothing. 相似文献
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In this study, the three-dimensional structure of the wild-type human telomerase RNA pseudoknot was predicted via molecular modeling. The wild-type pseudoknot structure is then compared to the recent NMR solution structure of the telomerase pseudoknot, which does not contain the U177 bulge. The removal of the bulge from the pseudoknot structure results in higher stability and significant reduction of activity of telomerase. We show that the effect of the bulge on the structure results in a significant transformation of the pseudoknot junction region where the starting base pairs are disrupted and unique triple base pairs are formed. We found that the formation of the junction region is greatly influenced by interactions of the U177 bulge with loop residues and rotation of residue A174. Moreover, this is the first study to our knowledge where a structure as complex as the pseudoknot has been solved by purely theoretical methods. 相似文献