Physical Sciences and Mathematics Commons^™

Large Sets Of Zero Analytic Capacity, John Garnett, Stan T. Yoshinobu

Mathematics

We prove that certain Cantor sets with non-sigma-finite one-dimensional Hausdorff measure have zero analytic capacity.

The Cataclysmic Variable Cw 1045+525: A Secondary-Dominated Dwarf Nova?, C. Tappert, J. R. Thorstensen, W. H. Fenton, N. Bennert, L. Schmidtobreick, A. Bianchini

Physics

We present spectroscopic and photometric observations of the cataclysmic variable CW 1045+525. Both the optical spectrum and the photometric lightcurve show a strong contribution of a K5V-M0V secondary. We derive an orbital period d by measuring the radial velocities of the absorption lines of the secondary. The period and spectral type of the secondary suggest a distance of 350-700 pc. There is evidence for additional sources of line- and continuum emission, but no direct evidence of an accretion disc. We discuss several scenarios for the nature of CW 1045+525 on the basis of our results, finding a dwarf nova classification …

Computer Sound Card Assisted Measurements Of The Acoustic Doppler Effect For Accelerated And Unaccelerated Sound Sources, Thomas J. Bensky, S. E. Frey

Physics

An approach to experimentally measuring the speed of a moving object by direct application of the Doppler effect for sound is discussed. The method presented here uses a Windows computer and sound card to record Doppler shifted sound from a moving source. This sound card approach allows for direct acquisition of Doppler shifted sound intensity as a function of time, affording much analytical and pedagogical freedom in undergraduate lab instruction. In addition, the acquisition of such data allows for the experimental study of not only constant velocity sound sources, but of accelerated sound sources as well.

Magnetite Morphology And Life On Mars, Peter R. Buseck, Rafal E. Dunin-Borkowski, Bertrand Devouard, Richard B. Frankel, Martha R. Mccartney, Paul A. Midgley, Mihály Pósfai, Mathew Weyland

Physics

Nanocrystals of magnetite (Fe₃O₄) in a meteorite from Mars provide the strongest, albeit controversial, evidence for the former presence of extraterrestrial life. The morphological and size resemblance of the crystals from meteorite ALH84001 to crystals formed by certain terrestrial bacteria has been used in support of the biological origin of the extraterrestrial minerals. By using tomographic and holographic methods in a transmission electron microscope, we show that the three-dimensional shapes of such nanocrystals can be defined, that the detailed morphologies of individual crystals from three bacterial strains differ, and that none uniquely match those reported from …

Sequential Searches: Proofreading, Russian Roulette, And The Incomplete Q-Eulerian Polynomials Revisited, Don Rawlings

Mathematics

No abstract provided.

Enhanced Double Ionization With Circularly Polarized Light, Glen D. Gillen, M. A. Walker, L. D. Van Woerkom

Physics

Using 120-fs, 800-nm Ti:sapphire laser pulses, ionic yields of singly and doubly charged magnesium ions were measured as a function of intensity and laser field ellipticity. A clear “nonsequential” enhancement of the doubly charged ion is observed for circularly polarized light in addition to linearly polarized light. Over the entire intensity range the double-ionization yield is considerably higher for linear polarization than it is for circular polarization.

Whose Limit Is It Anyway?, Joseph E. Borzellino

Mathematics

In a tongue-in-cheek manner, we investigate the notion of limit. We illustrate some of its shortcomings and show that addressing these shortcomings can often lead to unexpected consequences.

Computing Cyclomatic Complexity With Cubic Flowgraphs, Yongming Tang, Ali H. Dogru, Franz J. Kurfess, Murat M. Tanik

Computer Science and Software Engineering

Two new methods for the computation of cyclomatic complexity especially for decomposable representations are introduced. Building software by integration is a developing paradigm, especially enabled by the emerging component technologies. Decomposition of the design for a top-down approach is a prerequisite for this paradigm. Cubic flowgraphs are instrumental in providing formalisms for decomposition and integration. Cyclomatic complexity analysis of a design representation that is decomposable is the goal of this research. In addition to introducing cyclomatic complexity computation using cubic flowgraphs, preservation of cyclomatic complexity in the decomposition of the cubic flowgraph is also presented.

Magnetic Microstructure Of Bacterial Magnetite By Electron Holography, Martha R. Mccartney, Ulysses Lins, Marcos Farina, Peter R. Buseck, Richard B. Frankel

Physics

A brackish lagoon at Itaipu, Brazil, contains magnetotactic bacteria with unusually large magnetite magnetosomes (lengths 100–200 nm). The micromagnetic structures of the magnetosomes from two different coccoid organisms from the lagoon have been determined by electron holography. The results are consistent with single-magnetic-domain structure in the elongated magnetosomes from one organism and metastable, single-magnetic-domain structure in the larger, more equi-axed, magnetosomes from the other organism. The results are consistent with theoretical predictions of the transition dimension between stable and metastable single-domain structure in magnetite.

The Meaning Of An Information-Centric Computer Environment, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

It is often lamented that we human beings are suffering from an information overload. This is a myth, as shown in Fig.1 there is no information overload. Instead we are suffering from a data overload. The confusion between data and information is not readily apparent and requires further explanation. Unorganized data are voluminous but of very little value. Over the past 15 years, industry and commerce have made significant efforts to rearrange this unorganized data into purposeful data, utilizing various kinds of database management systems. However, even in this organized form, we are still dealing with data and not information.

Crystal-Size Distributions And Possible Biogenic Origin Of Fe Sulfides, Mihály Pósfai, Krisztina Cziner, Emö Márton, Péter Márton, Peter R. Buseck, Richard B. Frankel, Dennis A. Bazylinski

Physics

Sedimentary greigite (Fe₃S₄) can form either by ''biologically controlled'' or by ''biologically induced mineralization'' (BCM and BIM, respectively). In order to identify the origin of magnetic Fe sulfides, we studied and compared the sizes and morphologies of greigite crystals produced by a magnetotactic microorganism (previously described and referred to as the ''many-celled magnetotactic prokaryote'', MMP) and Fe sulfides from two specimens of Miocene sedimentary rocks (from Łaka, in the foredeep of the Western Carpathians and from Michalovce, in the Transcarpathian Depression). Greigite grains from the MMP and the Łaka rock show nearly Gaussian crystal-size distributions (CSDs), …

Off-Axis Electron Holography Of Magnetotactic Bacteria: Magnetic Microstructure Of Strains Mv-1 And Ms-1, R. E. Dunin-Borkowski, Martha R. Mccartney, Mihály Pósfai, Richard B. Frankel, Dennis A. Bazylinski, Peter R. Buseck

Physics

Off-axis electron holography in the transmission electron microscope is used to characterize the magnetic microstructure of magnetotactic bacteria. The practical details of the technique are illustrated through the examination of single cells of strains MV-1 and MS-1, which contain crystals of magnetite (Fe₃O₄) that are ~50nm in size and are arranged in chains. Electron holography allows the magnetic domain structures within the nanocrystals to be visualized directly at close to the nanometer scale. The crystals are shown to be single magnetic domains. The magnetization directions of small crystals that would be superparamagnetic if they were isolated …

Determination Of Surface Heterogeneity And Enthalpies Of Ca-K And Pb-K Systems In Tropical Soil Using Flow Adsorption Calorimetry, Chip Appel, Lena Ma, Dean Rhue, Bill Reve

Earth and Soil Sciences

No abstract provided.

Precise Environmental Searches: Integrating Hierarchical Information Search With Envirodaemon, George Chang, Gunjan Samtani, Marcus Healey, Franz J. Kurfess, Jason Wang

Computer Science and Software Engineering

Information retrieval has evolved from searches of references, to abstracts, to documents. Search on the Web involves search engines that promise to parse full-text and other files: audio, video, and multimedia. With the indexable Web at 320 million pages and growing, difficulties with locating relevant information have become apparent. The most prevalent means for information retrieval relies on syntax-based methods: keywords or strings of characters are presented to a search engine, and it returns all the matches in the available documents. This method is satisfactory and easy to implement, but it has some inherent limitations that make it unsuitable for …

“Soft” Anharmonic Vortex Glass In Ferromagnetic Superconductors, Leo Radzihovsky, A. M. Ettouhami, Karl Saunders, John Toner

Physics

Ferromagnetic order in superconductors can induce a spontaneous vortex (SV) state. For external field H = 0, rotational symmetry guarantees a vanishing tilt modulus of the SV solid, leading to drastically different behavior than that of a conventional, external-field-induced vortex solid. We show that quenched disorder and anharmoinc effects lead to elastic moduli that are wave-vector dependent out to arbitrarily long length scales, and non-Hookean elasticity. The latter implies that for weak external fields H, the magnetic induction scales universally like B(H)∼B(0)+cHα, with α≈0.72. For weak disorder, we predict the SV solid is a topologically ordered glass, in …

Randomized Motion Planning For Groups Of Nonholonomic Robots, Christopher M. Clark, Stephen M. Rock.

Computer Science and Software Engineering

This paper presents a technique for motion planning which is capable of planning trajectories for a large number of nonholonomic robots. The robots plan within a two dimensional environment that consists of stationary/moving obstacles, and fixed boundaries. Each robot uses randomized motion planner techniques based on Probabilistic Road Maps (PRM’s) to construct it’s own trajectory that is free of collisions with moving obstacles and other robots. The randomized motion planner allows easy integration of the robots nonholonomic constraint into the planning so that only kinematically consistent plans are constructed. It is important to include this constraint in the planning problem …

Topological Noise Removal, Igor Guskov, Zoë J. Wood

Computer Science and Software Engineering

Meshes obtained from laser scanner data often contain topological noise due to inaccuracies in the scanning and merging process. This topological noise complicates subsequent operations such as remeshing, parameterization and smoothing. We introduce an approach that removes unnecessary nontrivial topology from meshes. Using a local wave front traversal, we discover the local topolo-gies of the mesh and identify features such as small tunnels. We then identify non-separating cuts along which we cut and seal the mesh, reducing the genus and thus the topological complexity of the mesh.

Information-Centric Decision-Support Systems: A Blueprint For ‘Interoperability’, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

For the past 20 years the US military services have suffered under the limitations of stove-piped computer software applications that function as discrete entities within a fragmented data-processing environment. Lack of interoperability has been identified by numerous think tanks, advisory boards, and studies, as the primary information systems problem (e.g., Army Science Board 2000, Air Force SAB 2000 Command and Control Study, and NSB Network-Centric Naval Forces 2000). Yet, despite this level of attention, all attempts to achieve interoperability within the current data-centric information systems environment have proven to be expensive, unreliable, and generally unsuccessful.

Proceedings Of The 2001 Onr Decision-Support Workshop Series: Continuing The Revolution In Military Affairs, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

In August of 1998 the Collaborative Agent Design Research Center (CADRC) of the California Polytechnic State University in San Luis Obispo (Cal Poly), approached the Office of Naval Research (ONR) with the proposal for an annual workshop focusing on emerging concepts in decision-support systems for military applications. The proposal was considered timely by the ONR Logistics Program Office for at least two reasons. First, rapid advances in information systems technology over the past decade had produced distributed, collaborative computer-assistance capabilities with profound potential for providing meaningful support to military decision makers. Indeed, some systems based on these new capabilities such …

Perspective Filters As A Means For Interoperability Among Information-Centric Decision-Support Systems, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

No abstract provided.

Immaccs: A Multi-Agent Decision-Support System, Jens G. Pohl, Mark Porczak, Kym Jason Pohl, Russell Leighton, Hisham Assal, Alan Davis, Lakshmi Vempati, Anthony Wood

Collaborative Agent Design (CAD) Research Center

This report describes work performed by the Collaborative Agent Design Research Center for the US Marine Corps Warfighting Laboratory (MCWL), on the IMMACCS experimental decision-support system. IMMACCS (Integrated Marine Multi-Agent Command and Control System) incorporates three fundamental concepts that distinguish it from existing (i.e., legacy) command and control applications. First, it is a collaborative system in which computer-based agents assist human operators by monitoring, analyzing, and reasoning about events in near real-time. Second, IMMACCS includes an ontological model of the battlespace that represents the behavioral characteristics and relationships among real world entities such as friendly and enemy assets, infrastructure objects …

Instrument For The Measurement Of Hysteresis Loops Of Magnetotactic Bacteria And Other Systems Containing Submicron Magnetic Particles, Hendrik De Waard, James Hilsinger, Richard B. Frankel

Physics

An electronic control system for the measurement of hysteresis curves of microscopically observed magnetic structures such as chains of magnetosomes in magnetotactic bacteria suspended or swimming in water is described. Using continuous magnetic fields generated by four coils for guidance or orientation of the bacteria or other magnetic structures, and pulsed magnetic fields in two additional coils for changing the degree of magnetization in small steps, hysteresis curves can be traversed. The circuits described can be constructed with readily available components. The guiding- and pulsed-field coils can be fashioned in any standard machine shop. The typical sensitivity of the system …

A Laboratory-Based Nonlinear Dynamics Course For Science And Engineering Students, Nilgun Sungar, John P. Sharpe, Matthew J. Moelter, Neil Fleishon, Kent Morrison, Jean Mcdill, Rod Schoonover

Physics

We describe the implementation of a new laboratory-based interdisciplinary undergraduate course on nonlinear dynamical systems. Geometrical methods and data visualization techniques are especially emphasized. A novel feature of the course is a required laboratory where the students analyze the behavior of a number of dynamical systems. Most of the laboratory experiments can be economically implemented using equipment available in many introductory physics microcomputer-based laboratories.

Mage: A Distributed Programming Model, Earl Barr, Raju Pandey, Michael Haungs

Computer Science and Software Engineering

Writing distributed programs is difficult. To ease this task, we introduce a new programming abstraction. which we call a mobility attribute. Mobility attributes provide a syntax that describes the mobility semantics of program components. Programmers attach mobility attributes to program components to dynamically control the placement of these components within the network. Mobility attributes intercept component invocations and decide whether and where to move a component before the component executes. This allows the programmer to improve her program's run-time efficiency by colocating components and resources. We present MAGE, an object oriented distributed system, that supports mobility attributes and illustrates their …

Nitrogen And Phosphorus Use Efficiency In Stands Of Loblolly And Slash Pine, Christopher Dicus, Thomas J. Dean

Natural Resources Management and Environmental Sciences

Nitrogen and phosphorus use efficiency (NUE and PUE, respectively), the annual amount of stemwood produced per unit net N or P used in total aboveground production, were examined in 17-year-old pure stands of unthinned loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Englem.) planted at two spacings. Slash pine stands had a greater NUE and PUE than loblolly pine, which was attributed to greater relative allocation of aboveground production to stemwood, lower foliar N and P concentrations, and greater foliar retranslocation of N and P by slash pine. Compared to 2.4 x 2.4 meter spaced stands, …

Little Languages And Their Programming Environments, John Clements, Paul Graunke, Shriram Krishnamurthi, Matthias Felleisen

Computer Science and Software Engineering

Programmers constantly design, implement, and program in little languages. Two different approaches to the implementation of little languages have evolved. One emphasizes the design of little languages from scratch, using conventional technology to implement interpreters and compilers. The other advances the idea of extending a general-purpose host language; that is, the little language shares the host language's features (variables, data, loops, functions) where possible; its interpreters and compilers; and even its type soundness theorem. The second approach is often called a language embedding.

This paper directs the attention of little language designers to a badly neglected area: the programming environments …

Icdm: An Architecture And Toolkit In Support Of Agent-Based, Decision-Support Applications, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Agent-based, decision-support systems provide human decision-makers with a means of solving complex problems through collaboration with heterogeneous collections of both human and computer-based expert agents. Over the past decade the Collaborative Agent Design (CAD) Research Center has developed several proof-of-concept and production-oriented agent-based, decision-support systems for both commercial and Department of Defense applications. These applications range in domain from engineering design to tactical command and control. While diverse in application, each of these systems is predicated on the same set of fundamental principles derived from years of experience in this area. Primary among these principles are the notions of high-level …

Probabilistic Temporal Databases, I: Algebra, Alex Dekhtyar, Robert Ross, V. S. Subrahmanian

Computer Science and Software Engineering

Dyreson and Snodgrass have drawn attention to the fact that in many temporal database applications, there is often uncertainty present about the start time of events, the end time of events, the duration of events, etc. When the granularity of time is small (e.g. milliseconds), a statement such as "Packet p was shipped sometime during the first 5 days of January, 1998" leads to a massive amount of uncertainty (5 X 24 X 60 X 60 X 1000) possibilities. As noted in [41], past attempts to deal with uncertainty in databases have been restricted to relatively small amounts of uncertainty …

Method And Apparatus For Detection And Prevention Of Calling Card Fraud, Hooshmand Afsar, David S. Janzen, Mark Ross Erickson, Hazel Suzanne Shirley, Christine Louise Fogarty, Michael Scott Nielsen, Douglas Alan Clark

Computer Science and Software Engineering

A method and apparatus for detection and prevention of calling card fraud is disclosed. The invention provides enhanced intelligence and efficiency in part applying by a fraud analysis associated with a calling card bill type or service provider as identified by originating partitions in network switches. Additionally, the invention incorporates a case-subcase arrangement of fraud analysis information and conducts fraud analysis on a case-by-case basis, thereby providing streamlined handling of suspected fraud. Still additionally, the invention includes an administrative monitor that continuously collects and reviews fraud system status information to detect abnormalities in the system.

Transition From Data To Information, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

It is often lamented that we human beings are suffering from an information overload. This is a myth; as shown in Fig.1, there is no information overload. Instead, we are suffering from a data overload. The confusion between data and information is not readily apparent and requires further explanation. Unorganized data are voluminous but of very little value. Over the past 15 years, industry and commerce have made significant efforts to rearrange this unorganized data into purposeful data, utilizing various kinds of database management systems. However, even in this organized form, we are still dealing with data and not …