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Smith College

2007

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Articles 1 - 30 of 36

Full-Text Articles in Physical Sciences and Mathematics

Theory And Numerics Of Gravitational Waves From Preheating After Inflation, Jean-François Dufaux, Amanda Bergman, Gary Felder, Lev Kofman, Jean-Philippe Uzan Dec 2007

Theory And Numerics Of Gravitational Waves From Preheating After Inflation, Jean-François Dufaux, Amanda Bergman, Gary Felder, Lev Kofman, Jean-Philippe Uzan

Physics: Faculty Publications

Preheating after inflation involves large, time-dependent field inhomogeneities, which act as a classical source of gravitational radiation. The resulting spectrum might be probed by direct detection experiments if inflation occurs at a low enough energy scale. In this paper, we develop a theory and algorithm to calculate, analytically and numerically, the spectrum of energy density in gravitational waves produced from an inhomogeneous background of stochastic scalar fields in an expanding universe. We derive some generic analytical results for the emission of gravity waves by stochastic media of random fields, which can test the validity/accuracy of numerical calculations. We contrast our …

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Evidence For A Population Of High-Redshift Submillimeter Galaxies From Interferometric Imaging, Joshua D. Younger, Giovanni G. Fazio, Jia Sheng Huang, Min S. Yun, Grant W. Wilson, Matthew L.N. Ashby, Mark A. Gurwell, Kamson Lai, Alison B. Peck, Glen R. Petitpas, David J. Wilner, Daisuke Iono, Kotaro Kohno, Ryohei Kawabe, David H. Hughes, Itziar Aretxaga, Tracy Webb, Alejo Martínez-Sansigre, Sungeun Kim, Kimberly S. Scott, Jason Austermann, Thushara Perera, James Lowenthal, Eva Schinnerer, Vernesa Smolčić Dec 2007

Evidence For A Population Of High-Redshift Submillimeter Galaxies From Interferometric Imaging, Joshua D. Younger, Giovanni G. Fazio, Jia Sheng Huang, Min S. Yun, Grant W. Wilson, Matthew L.N. Ashby, Mark A. Gurwell, Kamson Lai, Alison B. Peck, Glen R. Petitpas, David J. Wilner, Daisuke Iono, Kotaro Kohno, Ryohei Kawabe, David H. Hughes, Itziar Aretxaga, Tracy Webb, Alejo Martínez-Sansigre, Sungeun Kim, Kimberly S. Scott, Jason Austermann, Thushara Perera, James Lowenthal, Eva Schinnerer, Vernesa Smolčić

Astronomy: Faculty Publications

We have used the Submillimeter Array to image a flux-limited sample of seven submillimeter galaxies, selected by the AzTEC camera on the JCMT at 1.1 mm, in the COSMOS field at 890 μm with ∼2″ resolution. All of the sources - two radio-bright and five radio-dim - are detected as single point sources at high significance (>6 σ), with positions accurate to ∼0.2″ that enable counterpart identification at other wavelengths observed with similarly high angular resolution. All seven have IRAC counterparts, but only two have secure counterparts in deep HST ACS imaging. As compared to the two radio-bright sources …

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The Slider-Pinning Problem, Audrey Lee, Ileana Streinu, Louis Theran Dec 2007

The Slider-Pinning Problem, Audrey Lee, Ileana Streinu, Louis Theran

Computer Science: Faculty Publications

A Laman mechanism is a flexible planar bar-and-joint framework with m ≤ 2n-3 edges and exactly k = 2n-m degrees of freedom. The slider-pinning problem is to eliminate all the degrees of freedom of a Laman mechanism, in an optimal fashion, by individually fixing x or y coordinates of vertices. We describe two easy to implement O(n2) time algorithms.

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Vertex Pops And Popturns, Greg Aloupis, Brad Ballinger, Prosenjit Bose, Mirela Damian, Erik D. Demaine, Martin L. Demaine, Robin Flatland, Ferran Hurtado, Stefan Langerman, Joseph O'Rourke, Perouz Taslakian, Godfried Toussaint Dec 2007

Vertex Pops And Popturns, Greg Aloupis, Brad Ballinger, Prosenjit Bose, Mirela Damian, Erik D. Demaine, Martin L. Demaine, Robin Flatland, Ferran Hurtado, Stefan Langerman, Joseph O'Rourke, Perouz Taslakian, Godfried Toussaint

Computer Science: Faculty Publications

No abstract provided.

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Unfolding Polyhedra Via Cut-Tree Truncation, Alex Benton, Joseph O'Rourke Dec 2007

Unfolding Polyhedra Via Cut-Tree Truncation, Alex Benton, Joseph O'Rourke

Computer Science: Faculty Publications

We prove that an infinite class of convex polyhedra, produced by restricted vertex truncations, always unfold without overlap. The class includes the "domes," providing a simpler proof that these unfold without overlap.

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Modeling T Tauri Winds From He I Λ10830 Profiles, John Kwan, Suzan Edwards, William Fischer Nov 2007

Modeling T Tauri Winds From He I Λ10830 Profiles, John Kwan, Suzan Edwards, William Fischer

Astronomy: Faculty Publications

The high opacity of He I λ10830 makes it an exceptionally sensitive probe of the inner wind geometry of accreting T Tauri stars. In this line, blueshifted absorption below the continuum results from simple scattering of stellar photons, a situation that is readily modeled without definite knowledge of the physical conditions and recourse to multilevel radiative transfer. We present theoretical line profiles for scattering in two possible wind geometries, a disk wind and a wind emerging radially from the star, and compare them to observed He I λ10830 profiles from a survey of classical T Tauri stars. The comparison indicates …

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Supercurrent Survival Under A Rosen-Zener Quench Of Hard-Core Bosons, I. Klich, Courtney Lannert, G. Refael Nov 2007

Supercurrent Survival Under A Rosen-Zener Quench Of Hard-Core Bosons, I. Klich, Courtney Lannert, G. Refael

Physics: Faculty Publications

We study the survival of supercurrents in a system of impenetrable bosons on a lattice, subject to a quantum quench from its critical superfluid phase to an insulating phase. We show that the evolution of the current when the quench follows a Rosen-Zener profile is exactly solvable. This allows us to analyze a quench of arbitrary rate, from a sudden destruction of the superfluid to a slow opening of a gap. The decay and oscillations of the current are analytically derived and studied numerically along with the momentum distribution after the quench. In the case of small supercurrent boosts ν, …

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Band Unfoldings And Prismatoids: A Counterexample, Joseph O'Rourke Oct 2007

Band Unfoldings And Prismatoids: A Counterexample, Joseph O'Rourke

Computer Science: Faculty Publications

This note shows that the hope expressed in [ADL+07]--that the new algorithm for edge-unfolding any polyhedral band without overlap might lead to an algorithm for unfolding any prismatoid without overlap--cannot be realized. A prismatoid is constructed whose sides constitute a nested polyhedral band, with the property that every placement of the prismatoid top face overlaps with the band unfolding.

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Unfolding Restricted Convex Caps, Joseph O'Rourke Sep 2007

Unfolding Restricted Convex Caps, Joseph O'Rourke

Computer Science: Faculty Publications

This paper details an algorithm for unfolding a class of convex polyhedra, where each polyhedron in the class consists of a convex cap over a rectangular base, with several restrictions: the cap’s faces are quadrilaterals, with vertices over an underlying integer lattice, and such that the cap convexity is "radially monotone," a type of smoothness constraint. Extensions of Cauchy’s arm lemma are used in the proof of non-overlap.

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Paving Hessenberg Varieties By Affines, Julianna S. Tymoczko Sep 2007

Paving Hessenberg Varieties By Affines, Julianna S. Tymoczko

Mathematics Sciences: Faculty Publications

Regular nilpotent Hessenberg varieties form a family of subvarieties of the flag variety arising in the study of quantum cohomology, geometric representation theory, and numerical analysis. In this paper we construct a paving by affines of regular nilpotent Hessenberg varieties for all classical types, generalizing results of De Concini-Lusztig-Procesi and Kostant. This paving is in fact the intersection of a particular Bruhat decomposition with the Hessenberg variety. The nonempty cells of the paving and their dimensions are identified by combinatorial conditions on roots. We use the paving to prove these Hessenberg varieties have no odd-dimensional homology.

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Characterizing Sparse Graphs By Map Decompositions, Ruth Haas, Audrey Lee, Ileana Streinu, Louis Theran Aug 2007

Characterizing Sparse Graphs By Map Decompositions, Ruth Haas, Audrey Lee, Ileana Streinu, Louis Theran

Mathematics Sciences: Faculty Publications

A map is a graph that admits an orientation of its edges so that each vertex has out-degree exactly 1. We characterize graphs which admit a decomposition into k edge-disjoint maps after: (1) the addition of any ℓ edges; (2) the addition of some ℓ edges. These graphs are identified with classes of sparse graphs; the results are also given in matroidal terms.

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Coexistence Of Superfluid And Mott Phases Of Lattice Bosons, R. A. Barankov, Courtney Lannert, S. Vishveshwara Jun 2007

Coexistence Of Superfluid And Mott Phases Of Lattice Bosons, R. A. Barankov, Courtney Lannert, S. Vishveshwara

Physics: Faculty Publications

Recent experiments on strongly interacting bosons in optical lattices have revealed the coexistence of spatially separated Mott-insulating and number-fluctuating phases. We explore the condensate properties of the number fluctuating phase trapped between the Mott-insulating regions and derive the associated collective-mode structure. We discuss the crossover of the interlayer properties between two- and three-dimensional behavior as a function of the lattice parameters and estimate the critical temperatures for the transition from the normal to superfluid state.

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Strain And Rotation Rate From Gps In Tibet, Anatolia, And The Altiplano, Richard W. Allmendinger, Robert Reilinger, John P. Loveless Jun 2007

Strain And Rotation Rate From Gps In Tibet, Anatolia, And The Altiplano, Richard W. Allmendinger, Robert Reilinger, John P. Loveless

Geosciences: Faculty Publications

Deformation measured by regional GPS networks in continental plateaus reflects the geologic and tectonic variability of the plateaus. For two collisional plateaus (Tibet and Anatolia) and one noncollisional (the Altiplano), we analyze the regional strain and rotation rate by inverting GPS velocities to calculate the full two-dimensional velocity gradient tensor. To test the method, we use gridded velocities determined from an elastic block model for the eastern Mediterranean/Middle East region and show that to a first order, the deformation calculated directly from the GPS vectors provides an accurate description of regional deformation patterns. Principal shortening and extension rate axes, vertical …

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Preheating And Affleck-Dine Leptogenesis After Thermal Inflation, Gary Felder, Hyunbyuk Kim, Wan-Il Park, Ewan D. Stewart Jun 2007

Preheating And Affleck-Dine Leptogenesis After Thermal Inflation, Gary Felder, Hyunbyuk Kim, Wan-Il Park, Ewan D. Stewart

Physics: Faculty Publications

Previously, we proposed a model of low energy Affleck-Dine leptogenesis in the context of thermal inflation. The lepton asymmetry is generated at the end of thermal inflation, which occurs at a relatively low energy scale with the Hubble parameter somewhere in the range 1 keV ≲ H ≲ 1 MeV. Thus Hubble damping will be ineffective in bringing the Affleck-Dine field into the lepton conserving region near the origin, leaving the possibility that the lepton number could be washed out. Previously, we suggested that preheating could damp the amplitude of the Affleck-Dine field allowing conservation of the lepton number. In …

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Epsilon-Unfolding Orthogonal Polyhedra, Mirela Damian, Robin Flatland, Joseph O'Rourke Jun 2007

Epsilon-Unfolding Orthogonal Polyhedra, Mirela Damian, Robin Flatland, Joseph O'Rourke

Computer Science: Faculty Publications

An unfolding of a polyhedron is produced by cutting the surface and flattening to a single, connected, planar piece without overlap (except possibly at boundary points). It is a long unsolved problem to determine whether every polyhedron may be unfolded. Here we prove, via an algorithm, that every orthogonal polyhedron (one whose faces meet at right angles) of genus zero may be unfolded. Our cuts are not necessarily along edges of the polyhedron, but they are always parallel to polyhedron edges. For a polyhedron of n vertices, portions of the unfolding will be rectangular strips which, in the worst case, …

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Homogenization Of Forest Plant Communities And Weakening Of Species-Environment Relationships Via Agricultural Land Use, Mark Vellend, Kris Verheyen, Kathryn M. Flinn, Hans Jacquemyn, Annette Kolb, Hans Van Calster, George Peterken, Bente Jessen Graae, Jesse Bellemare, Olivier Honnay, Jörg Brunet, Monika Wulf, Fritz Gerhardt, Martin Hermy May 2007

Homogenization Of Forest Plant Communities And Weakening Of Species-Environment Relationships Via Agricultural Land Use, Mark Vellend, Kris Verheyen, Kathryn M. Flinn, Hans Jacquemyn, Annette Kolb, Hans Van Calster, George Peterken, Bente Jessen Graae, Jesse Bellemare, Olivier Honnay, Jörg Brunet, Monika Wulf, Fritz Gerhardt, Martin Hermy

Biological Sciences: Faculty Publications

Disturbance may cause community composition across sites to become more or less homogenous, depending on the importance of different processes involved in community assembly. In north-eastern North America and Europe local (alpha) diversity of forest plants is lower in forests growing on former agricultural fields (recent forests) than in older (ancient) forests, but little is known about the influence of land-use history on the degree of compositional differentiation among sites (beta diversity). Here we analyse data from 1446 sites in ancient and recent forests across 11 different landscapes in north-eastern North America and Europe to demonstrate decreases in beta diversity …

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Late Cambrian (Steptoean) Sedimentation And Responses To Sea-Level Change Along The Northeastern Laurentian Margin: Insights From Carbon Isotope Stratigraphy, Bosiljka Glumac, Laurel E. Mutti May 2007

Late Cambrian (Steptoean) Sedimentation And Responses To Sea-Level Change Along The Northeastern Laurentian Margin: Insights From Carbon Isotope Stratigraphy, Bosiljka Glumac, Laurel E. Mutti

Geosciences: Faculty Publications

Carbon isotopes are applied as tools for stratigraphic correlation of poorly fossiliferous Upper Cambrian carbonate strata in the northern U.S. Appalachians. Upper Cambrian (Steptoean) marine carbonate rocks record a significant global positive carbon isotope excursion (δ 13C = +4‰-5‰ Vienna Peedee belemnite [VPDB]), the timing of which is well documented in fossiliferous sections elsewhere. The Steptoean excursion peaks at a sea-level lowstand that produced the Sauk II-Sauk III sequence boundary on the North American craton. In this study, this excursion is documented for the first time in the northern U.S. Appalachians in poorly exposed limestone debris flow and olistolith deposits …

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Relativistic Effects In Homogeneous Gold Catalysis, David J. Gorin, F. Dean Toste Mar 2007

Relativistic Effects In Homogeneous Gold Catalysis, David J. Gorin, F. Dean Toste

Chemistry: Faculty Publications

Transition-metal catalysts containing gold present new opportunities for chemical synthesis, and it is therefore not surprising that these complexes are beginning to capture the attention of the chemical community. Cationic phosphine-gold(i) complexes are especially versatile and selective catalysts for a growing number of synthetic transformations. The reactivity of these species can be understood in the context of theoretical studies on gold; relativistic effects are especially helpful in rationalizing the reaction manifolds available to gold catalysts. This Review draws on experimental and computational data to present our current understanding of homogeneous gold catalysis, focusing on previously unexplored reactivity and its application …

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Spatial Variation In Sea Urchins, Fish Predators, And Bioerosion Rates On Coral Reefs Of Belize, Jocelyn Brown-Saracino, Paulette Peckol, H. Allen Curran, Martha L. Robbart Mar 2007

Spatial Variation In Sea Urchins, Fish Predators, And Bioerosion Rates On Coral Reefs Of Belize, Jocelyn Brown-Saracino, Paulette Peckol, H. Allen Curran, Martha L. Robbart

Biological Sciences: Faculty Publications

Although sea urchins are critical for controlling macroalgae on heavily fished coral reefs, high densities threaten reefs, as urchins are also prodigous bioeroders. This study examined urchin population characteristics, bioerosion rates, their fish predators (Labridae), and potential competitors (Scaridae) on unprotected reefs and a reef within a marine protected area (MPA) in the lagoonal regions off Belize. Urchin density (<1 >m-2) and bioerosion rates (∼0.2 kg CaCO3m-2year-1) were lowest and members of the Labridae were the highest (∼20 fish 200 m-3) within the MPA, while several unprotected reefs had higher (∼18-40 m-2) urchin densities, lower Labridae abundances (1-3 fish 200 …

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Nonlinear Inflaton Fragmentation After Preheating, Gary Felder, Lev Kofman Feb 2007

Nonlinear Inflaton Fragmentation After Preheating, Gary Felder, Lev Kofman

Physics: Faculty Publications

We consider the nonlinear dynamics of inflaton fragmentation during and after preheating in the simplest model of chaotic inflation. While the earlier regime of parametric resonant particle production and the later turbulent regime of interacting fields evolving towards equilibrium are well identified and understood, the short intermediate stage of violent nonlinear dynamics remains less explored. Lattice simulations of fully nonlinear preheating dynamics show specific features of this intermediate stage: occupation numbers of the scalar particles are peaked, scalar fields become significantly nongaussian and the field dynamics become chaotic and irreversible. Visualization of the field dynamics in position space reveals that …

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Inflaton Fragmentation After Λφ4 Inflation, Gary Felder, Olga Navros Feb 2007

Inflaton Fragmentation After Λφ4 Inflation, Gary Felder, Olga Navros

Physics: Faculty Publications

We use lattice simulations to examine the detailed dynamics of inflaton fragmentation during and after preheating in λφ4 chaotic inflation. The dynamics are qualitatively similar to preheating after m2φ2 inflation, involving the exponential growth and subsequent expansion and collision of bubble-like inhomogeneities of the inflaton and other scalar fields. During this stage fluctuations of the fields become strongly non-Gaussian. In the quartic theory, the conformal nature of the theory allows us to extend our simulations to much greater times than is possible for the quadratic model. With these longer simulations we have been able to determine …

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Dynamics Of Condensate Shells: Collective Modes And Expansion, Courtney Lannert, T. C. Wei, S. Vishveshwara Jan 2007

Dynamics Of Condensate Shells: Collective Modes And Expansion, Courtney Lannert, T. C. Wei, S. Vishveshwara

Physics: Faculty Publications

We explore the physics of three-dimensional shell-shaped condensates, relevant to cold atoms in "bubble traps." We study the ground state of the condensate wave function, spherically symmetric collective modes, and expansion properties of such a shell using a combination of analytical and numerical techniques. We find two breathing-type modes with frequencies that are distinct from that of the filled spherical condensate. Upon trap release and subsequent expansion, we find that the system displays self-interference fringes. We estimate characteristic time scales, degree of mass accumulation, three-body loss, and kinetic energy release during expansion for a typical system of Rb87.

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Distributed Resource Participation In Local Balancing Energy Markets, Judith Cardell Jan 2007

Distributed Resource Participation In Local Balancing Energy Markets, Judith Cardell

Engineering: Faculty Publications

In response to the new and potentially conflicting economic and technical demands of independent, distributed resources, the power system requires a new means for coordinating system and market operations. Price signals are one mechanism available to coordinate the operation of a power system in the emerging competitive markets. This paper discusses the integration of distributed resources into the operations of the power system by means of organizing the resources into microgrids and allowing them to participate in local electricity markets through responding to price signals. The simulations of price signals proposed in this paper successively expand upon the current open …

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Paleosalinity History Of Middle Holocene Lagoonal And Lacustrine Deposits In The Enriquillo Valley, Dominican Republic Based On Pore Morphometrics And Isotope Geochemistry Of Ostracoda, Pamela Medley, Neil E. Tibert, William P. Patterson, H. Allen Curran, Lisa Greer, Jean-Paul Colin Jan 2007

Paleosalinity History Of Middle Holocene Lagoonal And Lacustrine Deposits In The Enriquillo Valley, Dominican Republic Based On Pore Morphometrics And Isotope Geochemistry Of Ostracoda, Pamela Medley, Neil E. Tibert, William P. Patterson, H. Allen Curran, Lisa Greer, Jean-Paul Colin

Geosciences: Faculty Publications

The southwestern region of the Dominican Republic (Enriquillo Valley) contains exceptionally well-preserved, relict marine and saline lake deposits of mid-Holocne age. Abundant euryhaline ostracodes found in this deposit include Cyprideis salebrosa, C. mexicana, C. similis, and C. edentata. Morphometric and geochemical analyses performed on Cyprideis spp. provide high δ18O and δ13C values that are coincident with relative abundances of irregularly shaped pores that permeate the ostracode carapace. We recognize three stratigraphic intervals with distinct ostracode pore shape and stable isotope trends: (I) a 4.5-5.0m interval that contains ostracodes with highly irregular shaped pores (multiradiate) and …

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Ichnogenic Porosity, High-Frequency Cyclostratigraphy, And Groundwater Flow In The Karst Biscayne Aquifer, Se Florida, Usa, Kevin Cunningham, H. Allen Curran Jan 2007

Ichnogenic Porosity, High-Frequency Cyclostratigraphy, And Groundwater Flow In The Karst Biscayne Aquifer, Se Florida, Usa, Kevin Cunningham, H. Allen Curran

Geosciences: Faculty Publications

No abstract provided.

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Ichnofacies, Ichnocoenoses, And Ichnofabrics Of Quaternary Shallow-Marine To Dunal Tropical Carbonates: A Model And Implications, H. Allen Curran Jan 2007

Ichnofacies, Ichnocoenoses, And Ichnofabrics Of Quaternary Shallow-Marine To Dunal Tropical Carbonates: A Model And Implications, H. Allen Curran

Geosciences: Faculty Publications

A model of five ichnocoenoses within the Skolithos and Psilonichnus ichnofacies characterizes the modern, Holocene, and Pleistocene coastal-carbonate depositional environments and limestones of the Bahamas, as well as the Miami Limestone of south Florida. The subtidal to intertidal ichnocosnoses of the Skolithos ichnofacies are dominated by trace-making activities and trace fossils of callianassid shrimp, which can create distinctive and maximum ichnofabrics. Fossil Upogebia vasquezi burrows found in intertidal calcarenites and burrows of the trace fossil Psilonichnus upsilon, most common in beach backshore beds, have excellent potential as stratigraphic markers and can be used as indicators of past sea-level positions. …

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Paleoenvironmental Reconstruction Of The Middle Eocene Trieste-Pazin Basin (Croatia) From Benthic Foraminiferal Assemblages, Sanja ŽIvkovic, Bosiljka Glumac Jan 2007

Paleoenvironmental Reconstruction Of The Middle Eocene Trieste-Pazin Basin (Croatia) From Benthic Foraminiferal Assemblages, Sanja ŽIvkovic, Bosiljka Glumac

Geosciences: Faculty Publications

Foraminiferal assemblages from four stratigraphic sections of the Trieste-Pazin basin in central Istria, Croatia (southwestern Tethyan realm) were investigated to reconstruct paleoenvironmental conditions and to determine the age of these deposits. The following five Middle Eocene planktonic foraminiferal zones were identified from the range and frequency of foraminiferal species: Globigerinatheka kugleri/Morozovella aragonensis Zone (E9), Acarinina topilensis Zone (E10), Morozovelloides lehneri Zone (E11), Orbulinoides beckmanni Zone (E12), and Morozovelloides crassatus Zone (E13). A data set of benthic foraminifera relative frequency has been subjected to R- and Q-mode cluster analyses to demonstrate the linkage between taxa distribution and paleoenvironmental gradients. Benthic foraminiferal …

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Emergence Of Singular Structures In Oldroyd-B Fluids, Becca Thomases, Michael Shelley Jan 2007

Emergence Of Singular Structures In Oldroyd-B Fluids, Becca Thomases, Michael Shelley

Mathematics Sciences: Faculty Publications

Numerical simulations reveal the formation of singular structures in the polymer stress field of a viscoelastic fluid modeled by the Oldroyd-B equations driven by a simple body force. These singularities emerge exponentially in time at hyperbolic stagnation points in the flow and their algebraic structure depends critically on the Weissenberg number. Beyond a first critical Weissenberg number the stress field approaches a cusp singularity, and beyond a second critical Weissenberg number the stress becomes unbounded exponentially in time. A local approximation to the solution at the hyperbolic point is derived from a simple ansatz, and there is excellent agreement between …

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In-Between Theory And Practice: Dialogues In Design Research, Arianna Bassoli, Johanna Brewer, Karen Martin Jan 2007

In-Between Theory And Practice: Dialogues In Design Research, Arianna Bassoli, Johanna Brewer, Karen Martin

Computer Science: Faculty Publications

Why Wait? and Betwixt are two of the workshops we have recently run on the theme of in-between-ness. The approach of social computing, where researchers work to understand how the socio-cultural aspects of human life relate to the design of new technologies, was the starting point for our investigation. By observing actual instances of in-between-ness in context we explored how design activities can be used as an opportunity to discuss and take positions on a specific theme, and as a space for narrowing the gap in design research between theoretical and practical thinking.

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Recognition-Based Motion Capture And The Humaneva Ii Test Data, Nicholas Howe Jan 2007

Recognition-Based Motion Capture And The Humaneva Ii Test Data, Nicholas Howe

Computer Science: Faculty Publications

Quantitative comparison of algorithms for human motion capture have been hindered by the lack of standard benchmarks. The development of the HumanEva I & II test sets provides an opportunity to assess the state of the art by evaluating existing methods on the new standardized test videos. This paper presents a comprehensive evaluation of a monocular recognition-based pose recovery algorithm on the HumanEva II clips. The results show that the method achieves a mean relative error of around 10-12 cm per joint.

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