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2011

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Two Phase Heuristic Algorithm For The University Course Timetabling Problem: The Case Of University Of Dar Es Salaam, A. R. Mushi, A. R. Mushi Dec 2011

Two Phase Heuristic Algorithm For The University Course Timetabling Problem: The Case Of University Of Dar Es Salaam, A. R. Mushi, A. R. Mushi

Tanzania Journal of Science

University course timetabling is the problem of scheduling resources such as lecturers, courses, and rooms to a number of timeslots over a planning horizon, normally a week, while satisfying a number of problem-specific constraints. Since timetabling problems differ from one institution to another, this paper investigated the case of the University of Dar Es salaam, based on the combination of Simulated Annealing (SA), and steepest descent in a two-phase approach. Solutions have been generated which greatly outperform the manually generated ones. Furthermore, the method compares well with previous work on Tabu Search but with faster execution time and higher quality …


Implementation Of A Tabu Search Heuristic For The Examinations Timetabling Problem, A. R. Mushi Dec 2011

Implementation Of A Tabu Search Heuristic For The Examinations Timetabling Problem, A. R. Mushi

Tanzania Journal of Science

This paper reports on the design and implementation of an algorithm for the construction of an examinations timetable. The Examinations Timetabling Problem is the problem of assigning examinations and candidates to time periods and examination rooms while satisfying a set of specific constraints. Every University has a different set of constraints and structure of examinations. Generally, timetabling problems are NP-Hard and therefore very difficult to solve. However, they are of great interest due to their important practical application in educational institutions. This paper discusses a heuristic algorithm basing on the examinations timetabling at the University of Dar es salaam. The …


Contact Metamorphism In The Supracrustal Rocks Of The Sukumaland Greenstone Belt In The North West Tanzania, N. Boniface Dec 2011

Contact Metamorphism In The Supracrustal Rocks Of The Sukumaland Greenstone Belt In The North West Tanzania, N. Boniface

Tanzania Journal of Science

Biotite-granite intrusions in meta-ironstones at Geita Hills and the Bukoli alkali-granite intrusion in metabasites at Mawemeru area produced heat that baked the respective country rocks through epidote-amphibolite- to amphibolite-facies. Critical and informative mineral assemblages in the metairostones of Geita Hills are garnet-grunerite-epidote-quartz and garnetferrogedrite- biotite-quartz and in the metabasites of Mawemeru is ferrotschermakite-(Naplagioclase)- quartz. Peak temperatures ranging between 438°C and 544°C were calculated from the above mineral assemblages and a pressure not exceeding 3 kbar was inferred to from the composition of magnesium-iron amphiboles (grunerite with XFe ratio of 0.83, i.e. Gru83). Hornfels textures in the metaironstones are suggested by …


Identification Of Clay Minerals Of The Eastern Southern Region Of Lake Victoria By Ethylene Glycol And Heat: X-Ray Diffraction And Infrared Spectroscopy Studies, E. H. J. Lugwisha Dec 2011

Identification Of Clay Minerals Of The Eastern Southern Region Of Lake Victoria By Ethylene Glycol And Heat: X-Ray Diffraction And Infrared Spectroscopy Studies, E. H. J. Lugwisha

Tanzania Journal of Science

The effect of glycol and heat on some clay minerals of the eastern southern region of Lake Victoria in Tanzania has been studied. First, Whole Rock Powder mount XRD analysis was carried out at the measuring range 2 # ranging between 2o – 65o. Four non-clay minerals found in samples were Na-feldspar, K-feldspar, pyrope and quartz. Oriented clay mineral XRD analysis diffractograms were developed when the air-dried samples were diffracted in measuring range 2# between 2oo – 32o. Main clay mineral groups found in the samples were kaolinite, illite and montmorillonite. After glycolating the samples, it was evident that kaolinite …


Razvoj Modela Kriterijev Za Odločanje O Uvedbi Elektronske Hrambe Dokumentov, Marjeta Horjak, Andrej Kovačič Dec 2011

Razvoj Modela Kriterijev Za Odločanje O Uvedbi Elektronske Hrambe Dokumentov, Marjeta Horjak, Andrej Kovačič

Economic and Business Review

The article deals with the importance and necessity of research on electronic storage of documents. No empirical research has been conducted in Slovenia on the relationship between regulatory complexity and its impact on decision-making when implementing electronic document storage in compliance with the law. The aim of the research is therefore to shed light on the issue of legally compliant electronic storage in the context of Slovenian regulations in comparison with other European countries and, based on the research findings, to propose recommendations for their development and the creation of a systematic approach and scientific knowledge on document storage. The …


Search For Ultrahigh Energy Neutrinos In Highly Inclined Events At The Pierre Auger Observatory, P. Abreu, M. Aglietta, E. J. Ahn, I. F.M. Albuquerque, D. Allard, I. Allekotte, J. Allen, P. Allison, J. Alvarez Castillo, J. Alvarez-Muñiz, M. Ambrosio, A. Aminaei, L. Anchordoqui, S. Andringa, T. Antičić, A. Anzalone, C. Aramo, E. Arganda, F. Arqueros, H. Asorey, P. Assis, J. Aublin, M. Ave, M. Avenier, G. Avila, T. Bäcker, M. Balzer, K. B. Barber, A. F. Barbosa, R. Bardenet, S. L.C. Barroso, B. Baughman, J. Bäuml Dec 2011

Search For Ultrahigh Energy Neutrinos In Highly Inclined Events At The Pierre Auger Observatory, P. Abreu, M. Aglietta, E. J. Ahn, I. F.M. Albuquerque, D. Allard, I. Allekotte, J. Allen, P. Allison, J. Alvarez Castillo, J. Alvarez-Muñiz, M. Ambrosio, A. Aminaei, L. Anchordoqui, S. Andringa, T. Antičić, A. Anzalone, C. Aramo, E. Arganda, F. Arqueros, H. Asorey, P. Assis, J. Aublin, M. Ave, M. Avenier, G. Avila, T. Bäcker, M. Balzer, K. B. Barber, A. F. Barbosa, R. Bardenet, S. L.C. Barroso, B. Baughman, J. Bäuml

Faculty Publications

The Surface Detector of the Pierre Auger Observatory is sensitive to neutrinos of all flavors above 0.1 EeV. These interact through charged and neutral currents in the atmosphere giving rise to extensive air showers. When interacting deeply in the atmosphere at nearly horizontal incidence, neutrinos can be distinguished from regular hadronic cosmic rays by the broad time structure of their shower signals in the water-Cherenkov detectors. In this paper we present for the first time an analysis based on down-going neutrinos. We describe the search procedure, the possible sources of background, the method to compute the exposure and the associated …


Enhanced Microbial Utilization Of Recalcitrant Cellulose By An Ex Vivo Cellulosome-Microbe Complex, Chun You, Xiao-Zhou Zhang, Noppadon Sathitsuksanoh, Lee R. Lynd Dec 2011

Enhanced Microbial Utilization Of Recalcitrant Cellulose By An Ex Vivo Cellulosome-Microbe Complex, Chun You, Xiao-Zhou Zhang, Noppadon Sathitsuksanoh, Lee R. Lynd

Dartmouth Scholarship

A cellulosome-microbe complex was assembled ex vivo on the surface of Bacillus subtilis displaying a miniscaffoldin that can bind with three dockerin-containing cellulase components: the endoglucanase Cel5, the processive endoglucanase Cel9, and the cellobiohydrolase Cel48. The hydrolysis performances of the synthetic cellulosome bound to living cells, the synthetic cellulosome, a noncomplexed cellulase mixture with the same catalytic components, and a commercial fungal enzyme mixture were investigated on low-accessibility recalcitrant Avicel and high accessibility regenerated amorphous cellulose (RAC). The cellbound cellulosome exhibited 4.5- and 2.3-fold-higher hydrolysis ability than cell-free cellulosome on Avicel and RAC, respectively. The cellulosome-microbe synergy was not completely …


Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen Dec 2011

Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen

All Faculty Scholarship for the College of the Sciences

Differences in the timing of glacial advances, which are commonly attributed to climatic changes, can be due to variations in valley topography. Cosmogenic 10Be dates from 24 glacial moraine boulders in 5 valleys define two age populations, late-glacial and early Holocene. Moraine ages correlate with paleoglacier valley hypsometries. Moraines in valleys with lower maximum altitudes date to the lateglacial, whereas those in valleys with higher maximum altitudes are early Holocene. Two valleys with similar equilibrium-line altitudes (ELAs), but contrasting ages, are < 5 km apart and share the same aspect, such that spatial differences in climate can be excluded. A glacial mass-balance cellular automata model of these two neighboring valleys predicts that change from a cooler-drier to warmer-wetter climate (as at the Holocene onset) would lead to the glacier in the higher altitude catchment advancing, while the lower one retreats or disappears, even though the ELA only shifted by ~120 m.


Optimizacija Procesa Razreza Po Skupinah, Mihael Cesar, Mirko Gradišar, Jure Erjavec, Luka Tomat Dec 2011

Optimizacija Procesa Razreza Po Skupinah, Mihael Cesar, Mirko Gradišar, Jure Erjavec, Luka Tomat

Economic and Business Review

The article proposes a method for solving a one-dimensional problem of cutting material in groups. The method is useful for large orders that, for technological and logistical reasons, cannot be fulfilled in one step but in several successive steps. The method has two stages. In the first stage, pairs of orders are calculated, which are combined into groups in the second stage. The method is carried out in the form of a computer algorithm of G- CUT and tested on a practical example.


Symmetry Breaking From Radiation Reaction In Ultra-Intense Laser Fields, Chris Harvey, Thomas Heinzl, Mattias Marklund Dec 2011

Symmetry Breaking From Radiation Reaction In Ultra-Intense Laser Fields, Chris Harvey, Thomas Heinzl, Mattias Marklund

School of Engineering, Computing and Mathematics

No abstract provided.


Partition Decoupling For Multi-Gene Analysis Of Gene Expression Profiling Data, Rosemary Braun, Gregory Leibon, Scott Pauls, Daniel Rockmore Dec 2011

Partition Decoupling For Multi-Gene Analysis Of Gene Expression Profiling Data, Rosemary Braun, Gregory Leibon, Scott Pauls, Daniel Rockmore

Dartmouth Scholarship

Background:

Multi-gene interactions likely play an important role in the development of complex phenotypes, and relationships between interacting genes pose a challenging statistical problem in microarray analysis, since the genes involved in these interactions may not exhibit marginal differential expression. As a result, it is necessary to develop tools that can identify sets of interacting genes that discriminate phenotypes without requiring that the classification boundary between phenotypes be convex.

Results:

We describe an extension and application of a new unsupervised statistical learning technique, known as the Partition Decoupling Method (PDM), to gene expression microarray data. This method may be used …


The Gap, The Trap, And The High Flyers Flaps: A Summary And Analysis Of Three Important Studies Focusing On Excellence Gaps In American Education, Jason S. Mcintosh Dec 2011

The Gap, The Trap, And The High Flyers Flaps: A Summary And Analysis Of Three Important Studies Focusing On Excellence Gaps In American Education, Jason S. Mcintosh

Gifted Children

America’s educational system has undergone major changes in the last decade. A focus on “proficiency,” high stakes testing, and standards-based curriculum has become the name of the game. As a result, more students are meeting minimum competency every year. Researchers from three different organizations recently examined the effects of these curricular changes on the performance of America’s highest achieving students. This article synthesizes and summarizes the Center for Evaluation and Educational Policy’s 2010 report entitled Mind the Other Gap: The Growing Excellence Gap in K-12 Education, the Jack Kent Cooke Foundation’s 2006 report entitled Achievement Trap: How America is Failing …


Effective Use Of Secondary Data Analysis In Gifted Education Research: Opportunities And Challenges, Christian E. Mueller, Caroline O. Hart Dec 2011

Effective Use Of Secondary Data Analysis In Gifted Education Research: Opportunities And Challenges, Christian E. Mueller, Caroline O. Hart

Gifted Children

No abstract provided.


Author Notes Dec 2011

Author Notes

Gifted Children

No abstract provided.


The Ap Challenge Program: Advancing Gifted Minority Student Achievement In High School And Beyond, Mary Nguyen, Carolyn M. Callahan, Dean L. Stevenson Dec 2011

The Ap Challenge Program: Advancing Gifted Minority Student Achievement In High School And Beyond, Mary Nguyen, Carolyn M. Callahan, Dean L. Stevenson

Gifted Children

No abstract provided.


Book Review: Differentiating For The Young Child: Teaching Strategies Across The Content Areas, Prek-3, Second Edition, By Joan Franklin Smutny And S. E. Von Fremd, Pamela L. Shue Dec 2011

Book Review: Differentiating For The Young Child: Teaching Strategies Across The Content Areas, Prek-3, Second Edition, By Joan Franklin Smutny And S. E. Von Fremd, Pamela L. Shue

Gifted Children

No abstract provided.


Studying Acceleration With National Datasets And Surveys: Some Suggestions, Some Results, And Our Experiences, David F. Lohman, Maureen A. Marron Dec 2011

Studying Acceleration With National Datasets And Surveys: Some Suggestions, Some Results, And Our Experiences, David F. Lohman, Maureen A. Marron

Gifted Children

No abstract provided.


Directional Limits On Persistent Gravitational Waves Using Ligo S5 Science Data, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. S. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, M. A. Arain, M. C. Araya, M. Aronsson, K. G. Arun, Y. Aso, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, D. Barker, S. Barnum, F. Barone Dec 2011

Directional Limits On Persistent Gravitational Waves Using Ligo S5 Science Data, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. S. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, M. A. Arain, M. C. Araya, M. Aronsson, K. G. Arun, Y. Aso, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, D. Barker, S. Barnum, F. Barone

Faculty Publications

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10-50strain2Hz-1 and 5-35×10 -49strain2Hz-1sr-1 for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets …


Noise, Bifurcations, And Modeling Of Interacting Particle Systems, Luis Mier-Y-Teran-Romero, Eric Forgoston, Ira B. Schwartz Dec 2011

Noise, Bifurcations, And Modeling Of Interacting Particle Systems, Luis Mier-Y-Teran-Romero, Eric Forgoston, Ira B. Schwartz

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

We consider the stochastic patterns of a system of communicating, or coupled, self-propelled particles in the presence of noise and communication time delay. For sufficiently large environmental noise, there exists a transition between a translating state and a rotating state with stationary center of mass. Time delayed communication creates a bifurcation pattern dependent on the coupling amplitude between particles. Using a mean field model in the large number limit, we show how the complete bifurcation unfolds in the presence of communication delay and coupling amplitude. Relative to the center of mass, the patterns can then be described as transitions between …


Impact Of National Board Certification, Advanced Degree, And Socio-Economic Status On The Literacy Achievement Rate Of 11th Grade Students In Arkansas, Merlina T. Mccullough Dec 2011

Impact Of National Board Certification, Advanced Degree, And Socio-Economic Status On The Literacy Achievement Rate Of 11th Grade Students In Arkansas, Merlina T. Mccullough

Student Theses and Dissertations

No abstract provided.


Correlation Of Inflation-Produced Magnetic Fields With Scalar Fluctuations, Robert R. Caldwell, Leonardo Motta, Marc Kamionkowski Dec 2011

Correlation Of Inflation-Produced Magnetic Fields With Scalar Fluctuations, Robert R. Caldwell, Leonardo Motta, Marc Kamionkowski

Dartmouth Scholarship

If the conformal invariance of electromagnetism is broken during inflation, then primordial magnetic fields may be produced. If this symmetry breaking is generated by the coupling between electromagnetism and a scalar field—e.g. the inflaton, curvaton, or Ricci scalar—then these magnetic fields may be correlated with primordial density perturbations, opening a new window to the study of non-Gaussianity in cosmology. In order to illustrate, we couple electromagnetism to an auxiliary scalar field in a de Sitter background. We calculate the power spectra for scalar-field perturbations and magnetic fields, showing how a scale-free magnetic-field spectrum with rms amplitude of ∼nG at Mpc …


Directional Limits On Persistent Gravitational Waves Using Ligo S5 Science Data, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. S. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, M. A. Arain, M. C. Araya, M. Aronsson, K. G. Arun, Y. Aso, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, D. Barker, Tiffany Z. Summerscales Dec 2011

Directional Limits On Persistent Gravitational Waves Using Ligo S5 Science Data, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. S. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, M. A. Arain, M. C. Araya, M. Aronsson, K. G. Arun, Y. Aso, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, D. Barker, Tiffany Z. Summerscales

Faculty Publications

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10-50strain2Hz-1 and 5-35×10 -49strain2Hz-1sr-1 for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets …


A Content Analysis Of Teacher Perceptions Of The Implementation Of Small Learning Communities At A High School, Christen Tonry Gonzalez Dec 2011

A Content Analysis Of Teacher Perceptions Of The Implementation Of Small Learning Communities At A High School, Christen Tonry Gonzalez

USF Tampa Graduate Theses and Dissertations

Educational reform is vital to meet the educational, social, and personal needs of an ever-changing student population. Many attempts at educational reform have been made over the past century. A number of reforms were originated and directed by policy at the Federal, State and regional levels, and others were developed at the district or school level. Demands for educational change are ever-present, and the acceptance of or resistance to change continues to be a topic of discussion and focus of research.

The purpose of this study was to understand change in the implementation of small learning communities (SLCs) at a …


The Hubble Space Telescope * Cluster Supernova Survey. Ii. The Type Ia Supernova Rate In High-Redshift Galaxy Clusters, K Barbary, G Aldering, R Amanullah, M Brodwin, N Connolly, Ks Dawson, M Doi, P Eisenhardt, L Faccioli, V Fadeyev, Hk Fakhouri, As Fruchter, D G. Gilbank, Md Gladders, G Goldhaber, A Goobar, T Hattori, E Hsiao, Xiaosheng Huang, Y Ihara, K Kashikawa, B Koester, K Konishi, M Kowalski, C Lidman, L Lubin, J Meyers, T Morokuma, T Oda, N Panagia, S Perlmutter, M Postman, P Ripoche, P Rosati, D Rubin, Dj Schlegel, Al Spadafora, Sa Stanford, M Strovink, N Suzuki, N Takanashi, K Tokita, N Yasuda Dec 2011

The Hubble Space Telescope * Cluster Supernova Survey. Ii. The Type Ia Supernova Rate In High-Redshift Galaxy Clusters, K Barbary, G Aldering, R Amanullah, M Brodwin, N Connolly, Ks Dawson, M Doi, P Eisenhardt, L Faccioli, V Fadeyev, Hk Fakhouri, As Fruchter, D G. Gilbank, Md Gladders, G Goldhaber, A Goobar, T Hattori, E Hsiao, Xiaosheng Huang, Y Ihara, K Kashikawa, B Koester, K Konishi, M Kowalski, C Lidman, L Lubin, J Meyers, T Morokuma, T Oda, N Panagia, S Perlmutter, M Postman, P Ripoche, P Rosati, D Rubin, Dj Schlegel, Al Spadafora, Sa Stanford, M Strovink, N Suzuki, N Takanashi, K Tokita, N Yasuda

Physics and Astronomy

We report a measurement of the Type Ia supernova (SN Ia) rate in galaxy clusters at 0.9 < z < 1.46 from the Hubble Space Telescope Cluster Supernova Survey. This is the first cluster SN Ia rate measurement with detected z > 0.9 SNe. Finding 8 ± 1 cluster SNe Ia, we determine an SN Ia rate of 0.50+0.23 –0.19 (stat) +0.10 –0.09 (sys) h 2 70 SNuB (SNuB ≡ 10–12 SNe L –1 ☉, B yr–1). In units of stellar mass, this translates to 0.36+0.16 –0.13 (stat) +0.07 –0.06 (sys) h 2 70 SNuM (SNuM ≡ 10–12 SNe M –1 ☉ yr–1). This represents a …


Superhalogen Properties Of Cumcln Clusters: Theory And Experiment, Y. J. Ko, H. Wang, K. Pradhan, P. Koirala, Anil K. Kandalam, K. H. Bowen, P. Jena Dec 2011

Superhalogen Properties Of Cumcln Clusters: Theory And Experiment, Y. J. Ko, H. Wang, K. Pradhan, P. Koirala, Anil K. Kandalam, K. H. Bowen, P. Jena

Physics & Engineering Faculty Publications

No abstract provided.


Twin Falls County V. Idaho Com'n On Redistricting Appellant's Reply Brief Dckt. 39373 Dec 2011

Twin Falls County V. Idaho Com'n On Redistricting Appellant's Reply Brief Dckt. 39373

Idaho Supreme Court Records & Briefs, All

No abstract provided.


Gravity Wave Heating And Cooling Of The Thermosphere: Sensible Heat Flux And Viscous Flux Of Kinetic Energy, Michael P. Hickey Ph.D., R. L. Walterscheid, G. Schubert Dec 2011

Gravity Wave Heating And Cooling Of The Thermosphere: Sensible Heat Flux And Viscous Flux Of Kinetic Energy, Michael P. Hickey Ph.D., R. L. Walterscheid, G. Schubert

Publications

Total wave heating is the sum of the convergence of the sensible heat flux and the divergence of the viscous flux of wave kinetic energy. Numerical simulations, using a full-wave model of the viscous damping of atmospheric gravity waves propagating in a nonisothermal atmosphere, are carried out to explore the relative contributions of these sources of wave heating as a function of wave properties and altitude. It is shown that the sensible heat flux always dominates in the lower thermosphere, giving a lower region of heating and an upper stronger region of cooling. The heating due to the divergence of …


Entangled-Photon Compressive Ghost Imaging, Petros Zerom, Kam Wai Clifford Chan, John C. Howell, Robert W. Boyd Dec 2011

Entangled-Photon Compressive Ghost Imaging, Petros Zerom, Kam Wai Clifford Chan, John C. Howell, Robert W. Boyd

Mathematics, Physics, and Computer Science Faculty Articles and Research

We have experimentally demonstrated high-resolution compressive ghost imaging at the single-photon level using entangled photons produced by a spontaneous parametric down-conversion source and using single-pixel detectors. For a given mean-squared error, the number of photons needed to reconstruct a two-dimensional image is found to be much smaller than that in quantum ghost imaging experiments employing a raster scan. This procedure not only shortens the data acquisition time, but also suggests a more economical use of photons for low-light-level and quantum image formation.


Science With A Skew: The Nuclear Power Industry After Chernobyl And Fukushima, Gayle Greene Dec 2011

Science With A Skew: The Nuclear Power Industry After Chernobyl And Fukushima, Gayle Greene

Scripps Faculty Publications and Research

It is one of the marvels of our time that the nuclear industry managed to resurrect itself from its ruins at the end of the last century, when it crumbled under its costs, inefficiencies, and mega-accidents. Chernobyl released hundreds of times the radioactivity of the Hiroshima and Nagasaki bombs combined, contaminating more than 40% of Europe and the entire Northern Hemisphere. But along came the nuclear lobby to breathe new life into the industry, passing off as “clean” this energy source that polluted half the globe. The “fresh look at nuclear”—in the words of a New York Times makeover piece …


Cluster Control Of Automated Surface Vessels, Paul David Mahacek Dec 2011

Cluster Control Of Automated Surface Vessels, Paul David Mahacek

Mechanical Engineering Senior Theses

This research focuses on the design and control of a fleet of robotic kayaks, and presents experimental data regarding the functionality and performance of the system. One of the key technical challenges in fielding multi-robot systems for real-world applications is the coordination and relative motion control of the individual units. Coordinated formation control of the fleet is implemented through the use of the cluster space control architecture, which is a full-order controller that treats the fleet as a virtual, articulating, kinematic mechanism. The resulting system is capable of autonomous navigation utilizing a centralized controller, currently implemented via a shore-based computer …