bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of cultivated barley (Hordeum vulgare). 1. Historical aspects, and phenetic character analysis of some characters by information theory and by spatial autocorrelation
Authors: Baum Bernard B.
Published: December 2009

A brief historical sketch of the classification of barley (Hordeum vulgare L.) cultivars is presented along with reference to key reviews on this subject. Characters, utilized in the comprehensive study on the barley cultivars of North America by Aberg and Wiebe (U.S. Department of Agriculture Technical Bulletin 942), were subjected to a series of phenetic character analyses using an information theory model and a spatial autocorrelation model. The ranking of the 48 characters in order of their importance (for classification and identification purposes) from the character analysis by information theory was compared with the previous rating of characters made by Aberg and Wiebe and was found to differ significantly. Numerous trials of character analysis by spatial autocorrelation using various Minkowski distances, setting various values among three parameters, never yielded results comparable with those obtained by Aberg and Wiebe. Among those trials, a few combinations of values for the three parameters (X, Y, and Z) yielded results comparable with those obtained with character analysis by information theory. Those same combinations of values were found by Estabrook and Gates (Taxon, 33: 13–25) in their study of Banisteriopsis in 1984, where they also developed the method of character analysis by spatial autocorrelation. Kernel weight was found to be the most important character.
A systematic revision of the genus Carex (Cyperaceae) with respect to the section Lupulinae
Authors: Menapace Francis J. , Wujek Daniel E. , Reznicek Anton A.
Published: December 2009

To assess the phenetic affiliation of species in Carex sect. Lupulinae, we examined achene epidermal micromorphology, using scanning electron microscopy. The newly disclosed differences in achene micromorphology, in particular the presence of silica platforms with or without central bodies, in conjunction with macromorphological features, support the division of section Lupulinae into subsection Lupulinae (comprises Carex lupulina, C. lupuliformis, C. louisianica, and C. gigantea) and subsection Intumescentes (comprises C. intumescens and C. grayi).
Microscopy of Fusarium solani infected rough lemon citrus fibrous roots
Authors: Nemec S. , Achor D. Stamper , Albrigo L. G.
Published: December 2009

Mode of Fusarium solani penetration into rough lemon citrus rootstock seedling fibrous roots was determined and root symptomatology was evaluated using light, scanning, and transmission electron microscopy. Roots contained limited subepidermal infection 15 h after inoculation. Invasion of epidermal cells was principally through broken epidermal and root hair cell walls, but direct penetration also occurred. Cortical infection was primarily intracellular. Severe root rot was present 36–60 h after inoculation and in most cases infection after 60 h resulted in disruption of the phloem and endodermis around the still relatively intact primary xylem. Naturally infected roots from field trees were collected in an advanced stage of rot. In these, F. solani digestion of middle lamellae of primary xylem was common, and infection and erosion of secondary vessel element walls occurred frequently.
Seasonal pattern of biomass allocation in flowering and nonflowering specimens of three Pinguicula species
Authors: Karlsson P. S.
Published: December 2009

The seasonal patterns of biomass allocation in flowering and nonflowering specimens of Pinguicula alpina L., P. villosa L., and P. vulgaris L. were compared in a subarctic environment. Pinguicula alpina had a large perennial root system, comprising 50% of the nonreproductive biomass. The other two species had smaller, annual roots, representing 5–10% of their biomass. Nonflowering specimens usually had winter buds about twice as large as flowering specimens, P. vulgaris varied, however, with site in this respect. Flowering P. alpina allocated approximately equal proportions of biomass to reproduction (flower stalk, capsule, and seeds) and over-wintering organs (bud and roots), while P. villosa's investment in reproduction was about five times that invested in the winter bud. For P. vulgaris, no correlation was found between the size of reproductive organs and the size of the bud. The number of seeds produced per capsule varied from 30 in P. villosa to 110–140 in the other two species. Seed weight was lower in P. alpina (15 μg/seed) than in P. vulgaris (24μg) and P. villosa (28μg). Plant biomass and reproductive effort varied between sites for P. vulgaris; however, this variation was apparently not related to differences in nutrient availability between sites.
Digital image measurement of the area and anatomical structure of tree rings
Authors: Yanosky Thomas M. , Robinove Charles J.
Published: December 2009

A microcomputer coupled to a video digitizer was used to develop methods for measuring areas of tree rings and for delineating and measuring microscopic anatomical features. Digitally imaged areas of individual rings of a loblolly pine cross section were within 2.6% of areas measured with a planimeter and were more accurate than areas calculated from radius widths. Various anatomical features were "mapped" within digitized images of consecutive rings, individual rings, and highly magnified parts of the rings of green ash. Fibers within various ring zones, including those known to have formed when trees were flooded, were readily differentiated on the basis of image brightness. The image-determined ratio of lumen to wall material within different groups of fibers was considered a measure of structural comparability. These techniques thus provide a rapid, accurate method to study relationships between tree rings and factors affecting their development. Methods could be improved by increasing both spatial and brightness resolution.
Induced vivipary in the sedge Cyperus virens and the transmission of the fungus Balansia cyperi (Clavicipitaceae)
Authors: Clay Keith
Published: December 2009

Individuals of the sedge Cyperus virens Mich. are frequently infected by the systemic fungus Balansia cyperi Edg. (Clavicipitaceae). Developing inflorescences of infected plants are enveloped by fungal hyphae, preventing their expansion. Viviparous plantlets are sometimes produced on the aborted inflorescences of infected plants and the plantlets themselves are infected by B. cyperi. To estimate the extent of infection and vivipary, five populations of C. virens from the southwestern coast of Louisiana were sampled along randomly located line transects. Approximately one-half of over 500 sampled plants were infected by B. cyperi and about 30% of the infected plants were viviparous. There were significant differences between transects within populations and among populations in the percentage of infected plants and of infected, viviparous plants. Viviparous, infected plants were, on average, four times as big as uninfected plants and three times as big as nonviviparous, infected plants. Induced vivipary represents a mechanism of vegetative reproduction where host plant and fungus are dispersed simultaneously in the same propagule.
Organization of the photosynthetic apparatus from triazine-resistant and -susceptible biotypes of several plant species
Authors: Lemoine Yves , Dubacq Jean-Paul , Zabulon Gerald , Ducruet Jean-Marc
Published: December 2009

To specify the relations between triazine resistance and modification of the photosynthetic apparatus, the organization of plastids from herbicide-resistant and -susceptible biotypes of Chenopodium album L., Amaranthus retroflexus L., Solanum nigrum L., Brassica campestris L., and Brassica napus L. has been compared. The plastids from resistant biotypes exhibit a higher degree of stacking owing to a paucity of stroma lamellae and irrespective of the granum size distribution. Their enrichment in chlorophyll b and xanthophylls results from a higher content in light-harvesting chlorophyll a/b – proteins (LHCP), especially of the oligomer LHCP1. The resulting enlargement of photosystem II antennae is correlated to the fluorescence properties of isolated plastids. The most important difference in the lipid composition of thylakoid membranes is the increase of the Δ3-trans-hexadecenoic acid proportion in phosphatidylglycerol from resistant plastids, which is thought to participate in the formation of the oligomeric structure of LHCP1. The slight increase of the unsaturation of lipids, especially of mono-galactosyldiacylglycerol, from resistant plastids, is but a consequence of their higher proportion of appressed membranes. These alterations in lipid composition and ultrastructure of the chloroplasts resemble those occurring in plants grown under low irradiance. This adaptative reorganization of thylakoid components seems to be a compensatory mechanism allowing the overcoming of limitations in the QA – QB electron transfer and, thus, its occurrence and extent depend on the light and temperature conditions of growth.
Fine structure of Classopollis exines
Authors: Rowley John R. , Srivastava Satish K.
Published: December 2009

Serial sections for light microscopy or transmission electron microscopy of two Classopollis pollen tetrads show that the exine structure, except for the nexine, has radially arranged rodlike units interwoven with transverse subunits. The nexine consists of strands or thin sheets except in the equatorial infratectal striate band area, where it is up to ca. 1 μm thick. Nexine is absent in the areas of the distal cryptopore and the subequatorial circumpolar infratectal canal. It is very thin or absent in the tetrad scar. Native contrast and reactivity to stain disappeared on immersion of thin sections in 1 M NaOH or HCl or in water. Reactivity to stains was regained after oxidizing the sections in KMnO4. Reactivity to stains appears to be dependent upon non-sporopollenin molecules embedded within exines. The above immersions remove stain reactive sites. Oxidative etching of sporopollenin exposes new sites. The specimens of Classopollis classoides Pflug studied and illustrated were picked from an Upper Jurassic sample (CRC 31519-2) collected at Osmington Mills locality, Dorset, England.
Observations on the variation in pollen morphology of Palmae and its significance
Authors: Ferguson I. K.
Published: December 2009

Study of the pollen morphology of the Palmae by using scanning electron microscopy and transmission electron microscopy shows that there is more remarkable variation and parallelism in pollen characters, especially exine ornamentation and stratification, than has been demonstrated previously. The pollen of Arenga borneensis has gemmate exine ornamentation and closely resembles that of species of the closely related Caryota (Caryoteae) as well as Iriartea and Dictyocaryum (Iriarteae). Some species of Pinanga (Areceae), Korthalsia, and Daemonorops (Calameae) have pollen which can only be separated from the A. borneensis type by careful electron microscope study. Other species of Arenga have spiny pollen with a smooth foot layer, which resemble Wallichia (Caryoteae) and other Caryota species. Catoblastus, Wettinia, and Socratea (Iriarteae) have similar characteristic pollen with columellate spines interspersed with dense scabrate ornamentation. Again, species of Pinanga and Korthalsia have superficially similar pollen, as do the genera Mauritia, Mauritiella, and Lepidocaryum (Lepidocaryeae). However, these groups can be distinguished by structural differences of the spines. Very similar tectate, perforate pollen with supratectal spines occur in genera which have small differences in apertures but are widely separated taxonomically. These include Pinanga, Nypa, Salacca (Calameae), and Ravenea (Ceroxyleae). In view of this variation and parallelism it is suggested that there is a need for caution in assigning fossil pollen to extant genera until a much more detailed and extensive study of palm pollen morphology is carried out.
VARIABLE NEIGHBORHOOD SEARCH FOR ORDER BATCHING IN A WAREHOUSE
Authors: ALBAREDA-SAMBOLA MARIA , ALONSO-AYUSO ANTONIO , MOLINA ELISENDA , DE BLAS CLARA SIMÓN
Published: December 2009

In this paper we address the problem of batching orders in a warehouse, with the objective of minimizing the total travel time. Order batching is an NP-hard optimization problem that is very difficult to solve exactly in practice. Thus, most implemented solutions are based on elementary heuristic methods that perform a relatively limited exploration of the solution space. As an alternative, we propose a heuristic based on variable neighborhood search, where the emphasis is placed on performing an intensive exploration of the most promising regions of the solution space. Simulations are conducted to study the performance of the method with different warehouse configurations, and an exhaustive comparative analysis, which considers all the best known heuristics, is carried out. The results obtained show that the proposed heuristic is competitive and that it provides a suitable method which can be used in practice. Additionally, since the performance of the algorithms depends heavily on factors such as storage policy, routing strategies, or the structure of the orders, we have developed an ANOVA in order to consider the effect of all the above factors on the different methods tested.
THERMAL TRANSPORT BY BALLISTIC PHONON IN A SEMICONDUCTOR RECTANGULAR QUANTUM WIRE MODULATED WITH QUANTUM DOT
Authors: YU XIAO-YAN , PENG XIAO-FANG , CHEN KE-QIU
Published: December 2009

Thermal transport by ballistic phonon in a semiconductor rectangular quantum wire modulated with quantum dot at low temperatures is investigated with the use of the scattering matrix method. The calculated results show that the total transmission coefficient versus the reduced phonon frequency exhibits interesting characteristics such as inhomogeneous quantum transport steps. Quantized thermal conductance plateau can be observed at low temperatures, and the thermal conductance is not increased monotonically with increasing temperature. The results also show that the phonon transport probability and thermal conductance can be controlled to a certain degree by adjusting the parameters of the proposed quantum structure.
OPTICAL ABSORPTION SPECTRA RELATED TO DONOR IMPURITIES IN GaAs/Ga1-xAlxAs RIDGE QUANTUM WIRE
Authors: KHORDAD R. , BIJANZADEH A. R.
Published: December 2009

The optical absorption spectra associated with transitions between the n = 1 valence level and the donor-impurity band in a V-groove GaAs / Ga 1-x Al x As quantum wire is calculated using a variational procedure within the effective mass approximation. Results are obtained for different dimensions of ridge quantum wire.
A VARIABLE MODIFIED CHAPLYGIN GAS MODEL WITH INTERACTION
Authors: XING LILI , GUI YUANXING , WANG CHUNYAN
Published: December 2009

We consider in this paper a variable modified Chaplygin gas (VMCG) model for describing the unification of dark energy and dark matter, in which dark energy interacts with dark matter. Concretely, the evolution of the VMCG model with interaction is discussed and the statefinder diagnostic for the model is performed. By analysis, we find that the effective state parameter of dark energy can cross the phantom divide wΛ= -1 and our universe will not end up with a Big Rip in the future. Furthermore, we perform a statefinder analysis on this scenario and show the discrimination between this scenario and other dark energy models.
CONSTRUCTING AN INHOMOGENEOUS BRANEWORLD THROUGH SPACE–TIME MATCHING
Authors: GIANG DAN , DYER CHARLES C.
Published: December 2009

We attempt to construct the braneworld analog of the cheese slice universe, an inhomogeneous cosmology constructed from alternating layers of Kasner and FLRW space–times. This construction is possible in four dimensions and we find that the energy conditions can be satisfied in the braneworld context. However, an extension into the bulk becomes more problematic. We use a 3 + 1 + 1 decomposition inspired by the ADM decompositions to show that structure is required in the bulk to support an inhomogeneous brane.
THE RATE OF CONVERGENCE OF q-BERNSTEIN–STANCU POLYNOMIALS
Authors: JIANG YANJIE , LI JUNMING
Published: December 2009

Let q > 0, α ≥ 0, f ∈ C[0, 1], and [Formula: see text] be the q-Bernstein–Stancu polynomials. In the case α = 0, [Formula: see text] reduces to the well-known q-Bernstein polynomials introduced by Phillips in 1997. In this paper, we study the rate of convergence of the sequence [Formula: see text]. Both a theorem on convergence and a Voronovskaya-type theorem on the rate of convergence are proved.
OPTIMAL LOWER ESTIMATES FOR THE WORST CASE CUBATURE ERROR AND THE APPROXIMATION BY HYPERINTERPOLATION OPERATORS IN THE SOBOLEV SPACE SETTING ON THE SPHERE
Authors: WANG HEPING
Published: December 2009

In this paper, we study two problems: one is of the worst case cubature error over the Sobolev classes on the sphere and another is of the approximation by hyperinterpolation operators on the sphere in the Sobolev space setting. We obtain lower estimates for the worst case cubature error over the Sobolev classes, which are optimal in the sense of order. We also obtain optimal estimates for the approximation by hyperinterpolation operators on the sphere in the Sobolev space setting.
DIMENSION REDUCTION OF MICROARRAY GENE EXPRESSION DATA: THE ACCELERATED FAILURE TIME MODEL
Authors: NGUYEN TUAN S. , ROJO JAVIER
Published: December 2009

The construction of the components of Partial Least Squares (PLS) is based on the maximization of the covariance/correlation between linear combinations of the predictors and the response. However, the usual Pearson correlation is influenced by outliers in the response or in the predictors. To cope with outliers, we replace the Pearson correlation with the Spearman rank correlation in the optimization criteria of PLS. The rank-based method of PLS is insensitive to outlying values in both the predictors and response, and incorporates the censoring information by using an approach of Nguyen and Rocke (2004) and two approaches of reweighting and mean imputation of Datta et al. (2007). The performance of the rank-based approaches of PLS, denoted by Rank-based Modified Partial Least Squares (RMPLS), Rank-based Reweighted Partial Least Squares (RRWPLS), and Rank-based Mean-Imputation Partial Least Squares (RMIPLS), is investigated in a simulation study and on four real datasets, under an Accelerated Failure Time (AFT) model, against their un-ranked counterparts, and several other dimension reduction techniques. The results indicate that RMPLS is a better dimension reduction method than other variants of PLS as well as other considered methods in terms of the minimized cross-validation error of fit and the mean squared error of fit in the presence of outliers in the response, and is comparable to other variants of PLS in the absence of outliers. Supplementary Materials are available at
IN SILICO SCREENING OF PROTEIN–PROTEIN INTERACTIONS WITH ALL-TO-ALL RIGID DOCKING AND CLUSTERING: AN APPLICATION TO PATHWAY ANALYSIS
Authors: MATSUZAKI YURI , MATSUZAKI YUSUKE , SATO TOSHIYUKI , AKIYAMA YUTAKA
Published: December 2009

We propose a computational screening system of protein–protein interactions using tertiary structure data. Our system combines all-to-all protein docking and clustering to find interacting protein pairs. We tuned our prediction system by applying various parameters and clustering algorithms and succeeded in outperforming previous methods. This method was also applied to a biological pathway estimation problem to show its use in network level analysis. The structural data were collected from the Protein Data Bank, PDB. Then all-to-all docking among target protein structures was conducted using a conventional protein–protein docking software package, ZDOCK. The highest-ranked 2000 decoys were clustered based on structural similarity among the predicted docking forms. The features of generated clusters were analyzed to estimate the biological relevance of protein–protein interactions. Our system achieves a best F-measure value of 0.43 when applied to a subset of general protein–protein docking benchmark data. The same system was applied to protein data in a bacterial chemotaxis pathway, utilizing essentially the same parameter set as the benchmark data. We obtained 0.45 for the F-measure value. The proposed approach to computational PPI detection is a promising methodology for mediating between structural studies and systems biology by utilizing cumulative protein structure data for pathway analysis.
Feature-aligned shape texturing
Authors: Xu Kai , Cohen-Or Daniel , Ju Tao , Liu Ligang , Zhang Hao , Zhou Shizhe , Xiong Yueshan
Published: December 2009

The essence of a 3D shape can often be well captured by its salient feature curves. In this paper, we explore the use of salient curves in synthesizing intuitive, shape-revealing textures on surfaces. Our texture synthesis is guided by two principles: matching the direction of the texture patterns to those of the salient curves, and aligning the prominent feature lines in the texture to the salient curves exactly. We have observed that textures synthesized by these principles not only fit naturally to the surface geometry, but also visually reveal, even reinforce, the shape's essential characteristics. We call these
feature-aligned shape texturing
. Our technique is fully automatic, and introduces two novel technical components in vector-field-guided texture synthesis: an algorithm that orients the salient curves on a surface for constrained vector field generation, and a feature-to-feature texture optimization.
Procedural modeling of structurally-sound masonry buildings
Authors: Whiting Emily , Ochsendorf John , Durand Frédo
Published: December 2009

We introduce structural feasibility into procedural modeling of buildings. This allows for more realistic structural models that can be interacted with in physical simulations. While existing structural analysis tools focus heavily on providing an analysis of the stress state, our proposed method automatically tunes a set of designated free parameters to obtain forms that are structurally sound.
Rendering surface details with diffusion curves
Authors: Jeschke Stefan , Cline David , Wonka Peter
Published: December 2009

Diffusion curve images
(DCI) provide a powerful tool for efficient 2D image generation, storage and manipulation. A DCI consist of curves with colors defined on either side. By diffusing these colors over the image, the final result includes sharp boundaries along the curves with smoothly shaded regions between them. This paper extends the application of diffusion curves to render high quality surface details on 3D objects. The first extension is a view dependent warping technique that dynamically reallocates texture space so that object parts that appear large on screen get more texture for increased detail. The second extension is a
dynamic
feature embedding technique that retains crisp, anti-aliased curve details even in extreme closeups. The third extension is the application of dynamic feature embedding to displacement mapping and geometry images. Our results show high quality renderings of diffusion curve textures, displacements, and geometry images, all rendered interactively.
Interactive reflection editing
Authors: Ritschel Tobias , Okabe Makoto , Thormählen Thorsten , Seidel Hans-Peter
Published: December 2009

Effective digital content creation tools must be both efficient in the interactions they provide but also allow full user control. There may be occasions, when art direction requires changes that contradict physical laws. In particular, it is known that physical correctness of reflections for the human observer is hard to assess. For many centuries, traditional artists have exploited this fact to depict reflections that lie outside the realm of physical possibility. However, a system that gives explicit control of this effect to digital artists has not yet been described. This paper introduces a system that transforms physically correct reflections into art-directed reflections, as specified by
reflection constraints
. The system introduces a taxonomy of reflection editing operations, using an intuitive user interface, that works directly on the reflecting surfaces with real-time visual feedback using a GPU. A user study shows how such a system can allow users to quickly manipulate reflections according to an art direction task.
Relief analysis and extraction
Authors: Zatzarinni Rony , Tal Ayellet , Shamir Ariel
Published: December 2009

We present an approach for extracting reliefs and details from relief surfaces. We consider a relief surface as a surface composed of two components: a base surface and a height function which is defined over this base. However, since the base surface is unknown, the decoupling of these components is a challenge. We show how to estimate a robust height function over the base, without explicitly extracting the base surface. This height function is utilized to separate the relief from the base. Several applications benefiting from this extraction are demonstrated, including relief segmentation, detail exaggeration and dampening, copying of details from one object to another, and curve drawing on meshes.
Abstraction of man-made shapes
Authors: Mehra Ravish , Zhou Qingnan , Long Jeremy , Sheffer Alla , Gooch Amy , Mitra Niloy J.
Published: December 2009

Man-made objects are ubiquitous in the real world and in virtual environments. While such objects can be very detailed, capturing every small feature, they are often identified and characterized by a small set of defining curves. Compact, abstracted shape descriptions based on such curves are often visually more appealing than the original models, which can appear to be visually cluttered. We introduce a novel algorithm for abstracting three-dimensional geometric models using characteristic curves or contours as building blocks for the abstraction. Our method robustly handles models with poor connectivity, including the extreme cases of polygon soups, common in models of man-made objects taken from online repositories. In our algorithm, we use a two-step procedure that first approximates the input model using a manifold, closedenvelopesurface and then extracts from it a hierarchical abstraction curve network along with suitable normal information. The constructed curve networks form a compact, yet powerful, representation for the input shapes, retaining their key shape characteristics while discarding minor details and irregularities.
Partial intrinsic reflectional symmetry of 3D shapes
Authors: Xu Kai , Zhang Hao , Tagliasacchi Andrea , Liu Ligang , Li Guo , Meng Min , Xiong Yueshan
Published: December 2009

While many 3D objects exhibit various forms of global symmetries, prominent intrinsic symmetries which exist only on parts of an object are also well recognized. Such partial symmetries are often seen as more natural than a global one, even when the symmetric parts are under complex pose. We introduce an algorithm to extract
partial intrinsic reflectional symmetries
(PIRS) of a 3D shape. Given a closed 2-manifold mesh, we develop a voting scheme to obtain an intrinsic reflectional symmetry axis (IRSA) transform, which is a scalar field over the mesh that accentuates prominent IRSAs of the shape. We then extract a set of explicit IRSA curves on the shape based on a refined measure of local reflectional symmetry support along a curve. The iterative refinement procedure combines IRSA-induced region growing and region-constrained symmetry support refinement to improve accuracy and address potential issues arising from rotational symmetries in the shape. We show how the extracted IRSA curves can be incorporated into a conventional mesh segmentation scheme so that the implied symmetry cues can be utilized to obtain more meaningful results. We also demonstrate the use of IRSA curves for symmetry-driven part repair.
Packing circles and spheres on surfaces
Authors: Schiftner Alexander , Höbinger Mathias , Wallner Johannes , Pottmann Helmut
Published: December 2009

Inspired by freeform designs in architecture which involve circles and spheres, we introduce a new kind of triangle mesh whose faces' incircles form a packing. As it turns out, such meshes have a rich geometry and allow us to cover surfaces with circle patterns, sphere packings, approximate circle packings, hexagonal meshes which carry a torsion-free support structure, hybrid tri-hex meshes, and others. We show how triangle meshes can be optimized so as to have the incircle packing property. We explain their relation to conformal geometry and implications on solvability of optimization. The examples we give confirm that this kind of meshes is a rich source of geometric structures relevant to architectural geometry.
Adaptive wavelet rendering
Authors: Overbeck Ryan S. , Donner Craig , Ramamoorthi Ravi
Published: December 2009

Effects such as depth of field, area lighting, antialiasing and global illumination require evaluating a complex high-dimensional integral at each pixel of an image. We develop a new adaptive rendering algorithm that greatly reduces the number of samples needed for Monte Carlo integration. Our method renders directly into an image-space wavelet basis. First, we adaptively distribute Monte Carlo samples to reduce the variance of the wavelet basis' scale coefficients, while using the wavelet coefficients to find edges. Working in wavelets, rather than pixels, allows us to sample not only image-space edges but also other features that are smooth in the image plane but have high variance in other integral dimensions. In the second stage, we reconstruct the image from these samples by using a suitable wavelet approximation. We achieve this by subtracting an estimate of the error in each wavelet coefficient from its magnitude, effectively producing the smoothest image consistent with the rendering samples. Our algorithm renders scenes with significantly fewer samples than basic Monte Carlo or adaptive techniques. Moreover, the method introduces minimal overhead, and can be efficiently included in an optimized ray-tracing system.
Structured annotations for 2D-to-3D modeling
Authors: Gingold Yotam , Igarashi Takeo , Zorin Denis
Published: December 2009

We present a system for 3D modeling of free-form surfaces from 2D sketches. Our system frees users to create 2D sketches from arbitrary angles using their preferred tool, which may include pencil and paper. A 3D model is created by placing primitives and annotations on the 2D image. Our primitives are based on commonly used sketching conventions and allow users to maintain a single view of the model. This eliminates the frequent view changes inherent to existing 3D modeling tools, both traditional and sketch-based, and enables users to match input to the 2D guide image. Our annotations---same-lengths and angles, alignment, mirror symmetry, and connection curves---allow the user to communicate higher-level semantic information; through them our system builds a consistent model even in cases where the original image is inconsistent. We present the results of a user study comparing our approach to a conventional "sketch-rotate-sketch" workflow.
Analytic drawing of 3D scaffolds
Authors: Schmidt Ryan , Khan Azam , Singh Karan , Kurtenbach Gord
Published: December 2009

We describe a novel approach to inferring 3D curves from perspective drawings in an interactive design tool. Our methods are based on a traditional design drawing style known as
analytic drawing
, which supports precise image-space construction of a linear 3D scaffold. This scaffold in turn acts as a set of visual constraints for sketching 3D curves. We implement analytic drawing techniques in a pure-inference sketching interface which supports both single-and multi-view incremental construction of complex scaffolds and curve networks. A new representation of 3D drawings is proposed, and useful interactive drawing aids are described. Novel techniques are presented for deriving constraints from single-view sketches drawn relative to the current 3D scaffold, and then inferring 3D line and curve geometry which satisfies these constraints. The resulting analytic drawing tool allows 3D drawings to be constructed using exactly the same strokes as one would make on paper.
DiagSplit
Authors: Fisher Matthew , Fatahalian Kayvon , Boulos Solomon , Akeley Kurt , Mark William R. , Hanrahan Pat
Published: December 2009

We present DiagSplit, a parallel algorithm for adaptively tessellating displaced parametric surfaces into high-quality, crack-free micropolygon meshes. DiagSplit modifies the split-dice tessellation algorithm to allow splits along non-isoparametric directions in the surface's parametric domain, and uses a dicing scheme that supports unique tessellation factors for each subpatch edge. Edge tessellation factors are computed using only information local to subpatch edges. These modifications allow all subpatches generated by DiagSplit to be processed independently without introducing T-junctions or mesh cracks and without incurring the tessellation overhead of binary dicing. We demonstrate that DiagSplit produces output that is better (in terms of image quality and number of micropolygons produced) than existing parallel tessellation schemes, and as good as highly adaptive split-dice implementations that are less amenable to parallelization.
3D polyomino puzzle
Authors: Lo Kui-Yip , Fu Chi-Wing , Li Hongwei
Published: December 2009

This paper presents a computer-aided geometric design approach to realize a new genre of 3D puzzle, namely the
3D Polyomino puzzle
. We base our puzzle pieces on the family of 2D shapes known as
polyominoes
in recreational mathematics, and construct the 3D puzzle model by covering its geometry with polyominolike shapes. We first apply quad-based surface parametrization to the input solid, and tile the parametrized surface with polyominoes. Then, we construct a nonintersecting offset surface inside the input solid and shape the puzzle pieces to fit inside a thick shell volume. Finally, we develop a family of associated techniques for precisely constructing the geometry of individual puzzle pieces, including the ring-based ordering scheme, the motion space analysis technique, and the tab and blank construction method. The final completed puzzle model is guaranteed to be not only buildable, but also interlocking and maintainable.
The graph camera
Authors: Popescu Voicu , Rosen Paul , Adamo-Villani Nicoletta
Published: December 2009

A conventional pinhole camera captures only a small fraction of a 3-D scene due to occlusions. We introduce the graph camera, a non-pinhole with rays that circumvent occluders to create a single layer image that shows simultaneously several regions of interest in a 3-D scene. The graph camera image exhibits good continuity and little redundancy. The graph camera model is literally a graph of tens of planar pinhole cameras. A fast projection operation allows rendering in feed-forward fashion, at interactive rates, which provides support for dynamic scenes. The graph camera is an infrastructure level tool with many applications. We explore the graph camera benefits in the contexts of virtual 3-D scene exploration and summarization, and in the context of real-world 3-D scene visualization. The graph camera allows integrating multiple video feeds seamlessly, which enables monitoring complex real-world spaces with a single image.
A practical approach for photometric acquisition of hair color
Authors: Zinke Arno , Rump Martin , Lay Tomás , Weber Andreas , Andriyenko Anton , Klein Reinhard
Published: December 2009

In this work a practical approach to photometric acquisition of hair color is presented. Based on a single input photograph of a simple setup we are able to extract physically plausible optical properties of hair and to render virtual hair closely matching the original. Our approach does not require any costly special hardware but a standard consumer camera only.
Optimizing walking controllers
Authors: Wang Jack M. , Fleet David J. , Hertzmann Aaron
Published: December 2009

This paper describes a method for optimizing the parameters of a physics-based controller for full-body, 3D walking. A modified version of the SIMBICON controller [Yin et al. 2007] is optimized for characters of varying body shape, walking speed and step length. The objective function includes terms for power minimization, angular momentum minimization, and minimal head motion, among others. Together these terms produce a number of important features of natural walking, including active toe-off, near-passive knee swing, and leg extension during swing. We explain the specific form of our objective criteria, and show the importance of each term to walking style. We demonstrate optimized controllers for walking with different speeds, variation in body shape, and in ground slope.
Compact character controllers
Authors: Lee Yongjoon , Lee Seong Jae , Popović Zoran
Published: December 2009

We present methods for creating compact and efficient data-driven character controllers. Our first method identifies the essential motion data examples tailored for a given task. It enables complex yet efficient high-dimensional controllers, as well as automatically generated connecting controllers that merge a set of independent controllers into a much larger aggregate one without modifying existing ones. Our second method iteratively refines basis functions to enable highly complex value functions. We show that our methods dramatically reduce the computation and storage requirement of controllers and enable very complex behaviors.
Robust task-based control policies for physics-based characters
Authors: Coros Stelian , Beaudoin Philippe , van de Panne Michiel
Published: December 2009

We present a method for precomputing robust task-based control policies for physically simulated characters. This allows for characters that can demonstrate skill and purpose in completing a given task, such as walking to a target location, while physically interacting with the environment in significant ways. As input, the method assumes an abstract action vocabulary consisting of balance-aware, step-based controllers. A novel constrained state exploration phase is first used to define a character dynamics model as well as a finite volume of character states over which the control policy will be defined. An optimized control policy is then computed using reinforcement learning. The final policy spans the cross-product of the character state and task state, and is more robust than the conrollers it is constructed from. We demonstrate real-time results for six locomotion-based tasks and on three highly-varied bipedal characters. We further provide a game-scenario demonstration.
Modeling spatial and temporal variation in motion data
Authors: Lau Manfred , Bar-Joseph Ziv , Kuffner James
Published: December 2009

We present a novel method to model and synthesize variation in motion data. Given a few examples of a particular type of motion as input, we learn a generative model that is able to synthesize a family of spatial and temporal variants that are statistically similar to the input examples. The new variants retain the features of the original examples, but are
not exact copies
of them. We learn a Dynamic Bayesian Network model from the input examples that enables us to capture properties of conditional independence in the data, and model it using a multivariate probability distribution. We present results for a variety of human motion, and 2D handwritten characters. We perform a user study to show that our new variants are less repetitive than typical game and crowd simulation approaches of re-playing a small number of existing motion clips. Our technique can synthesize new variants efficiently and has a small memory requirement.
Real-time prosody-driven synthesis of body language
Authors: Levine Sergey , Theobalt Christian , Koltun Vladlen
Published: December 2009

Human communication involves not only speech, but also a wide variety of gestures and body motions. Interactions in virtual environments often lack this multi-modal aspect of communication. We present a method for automatically synthesizing body language animations directly from the participants' speech signals, without the need for additional input. Our system generates appropriate body language animations by selecting segments from motion capture data of real people in conversation. The synthesis can be performed progressively, with no advance knowledge of the utterance, making the system suitable for animating characters from live human speech. The selection is driven by a hidden Markov model and uses prosody-based features extracted from speech. The training phase is fully automatic and does not require hand-labeling of input data, and the synthesis phase is efficient enough to run in real time on live microphone input. User studies confirm that our method is able to produce realistic and compelling body language.
Static analysis of active XML systems
Authors: Abiteboul Serge , Segoufin Luc , Vianu Victor
Published: December 2009

Active XML is a high-level specification language tailored to data-intensive, distributed, dynamic Web services. Active XML is based on XML documents with embedded function calls. The state of a document evolves depending on the result of internal function calls (local computations) or external ones (interactions with users or other services). Function calls return documents that may be active, and so may activate new subtasks. The focus of this article is on the verification of temporal properties of runs of Active XML systems, specified in a tree-pattern-based temporal logic, Tree-LTL, which allows expressing a rich class of semantic properties of the application. The main results establish the boundary of decidability and the complexity of automatic verification of Tree-LTL properties.
Casper*
Authors: Chow Chi-Yin , Mokbel Mohamed F. , Aref Walid G.
Published: December 2009

In this article, we present a new privacy-aware query processing framework,
Capser
*, in which mobile and stationary users can obtain snapshot and/or continuous location-based services without revealing their private location information. In particular, we propose a
privacy-aware query processor
embedded inside a location-based database server to deal with snapshot and continuous queries based on the knowledge of the user's cloaked location rather than the exact location. Our proposed
privacy-aware query processor
is completely independent of how we compute the user's cloaked location. In other words, any existing location anonymization algorithms that blur the user's private location into cloaked rectilinear areas can be employed to protect the user's location privacy. We first propose a
privacy-aware query processor
that not only supports three new privacy-aware query types, but also achieves a trade-off between query processing cost and answer optimality. Then, to improve system scalability of processing continuous privacy-aware queries, we propose a
shared execution paradigm
that shares query processing among a large number of continuous queries. The proposed scalable paradigm can be tuned through two parameters to trade off between system scalability and answer optimality. Experimental results show that our query processor achieves high quality snapshot and continuous location-based services while supporting queries and/or data with cloaked locations.
Constructing comprehensive summaries of large event sequences
Authors: Kiernan Jerry , Terzi Evimaria
Published: December 2009

Event sequences capture system and user activity over time. Prior research on sequence mining has mostly focused on discovering local patterns appearing in a sequence. While interesting, these patterns do not give a comprehensive summary of the entire event sequence. Moreover, the number of patterns discovered can be large. In this article, we take an alternative approach and build
short
summaries that describe an entire sequence, and discover local dependencies between event types.

We formally define the summarization problem as an optimization problem that balances shortness of the summary with accuracy of the data description. We show that this problem can be solved optimally in polynomial time by using a combination of two dynamic-programming algorithms. We also explore more efficient greedy alternatives and demonstrate that they work well on large datasets. Experiments on both synthetic and real datasets illustrate that our algorithms are efficient and produce high-quality results, and reveal interesting local structures in the data.
Eliminating method redundancy for the improvement of inner class design
Authors: Tee Sim Hui
Published: December 2009

Inner class is a helper class that assists its outer class to perform a specific task. It is declared within the body of outer class. An outer class can contain multiple inner classes in term of breadth and depth. The design principle of inner classes is to have them defined cohesively related to the functionality of outer class. However, method redundancy always renders overheads in inner class design. Eliminating method redundancy is significant because it can reduce the class complexity and enhance the class cohesiveness. This research examines the method redundancy in the inner classes. The author proposes a methodology to rate the complexity of redundant methods in order to reduce class complexity and enhance the inner class design.
The epistemology of computer security
Authors: Schaefer Robert
Published: December 2009

This paper studies computer security from first principles. The basic questions "Why?", "How do we know what we know?" and "What are the implications of what we believe?"
Sensible Tools of Engagement
Authors: Beck Debra
Published: December 2009

In teaching both traditional undergraduates(17-25 years old) and non-traditional graduate students, I've found that age is not necessarily the deciding factor for judging a student's comfort level with technology. Some of my more media-savvy students have been my age or older, while some of those who struggled most were younger. In my experience, the following three types of technology (beyond the threaded discussions that take place online) are within the reach of the majority of my students and are the most useful teaching tools: podcasts, wiki-based group projects, and social bookmarking.
An extensible, pervasive systems, application server
Authors: Munch-Ellingsen Arne , Andersen Anders , Blair Gordon , Issarny Valerie , Griwodz Carsten , Yu Weihai
Published: December 2009

Pervasive systems, with their interconnected mesh of devices, have some similarities, but pervasive systems are mostly diverse and will certainly change over time. Within these pervasive systems, the applications come in many varieties (e.g: context aware, QoS aware, multimedia, realtime, games, discrete, ubiquitous and domain specific as in health care applications, tourist application, etc.). The users expect that the applications are available on many devices (stationary and mobile and sometimes even ubiquitous).
Regulation of Smooth Muscle Contraction by Small GTPases
Authors: Puetz Sandra , Lubomirov Lubomir T. , Pfitzer Gabriele
Published: December 2009

Next to changes in cytosolic [Ca2+], members of the Rho subfamily of small GTPases, in particular Rho and its effector Rho kinase, also known as ROK or ROCK, emerged as key regulators of smooth muscle function in health and disease. In this review, we will focus on the regulation of the contractile machinery by Rho/ROK signaling and its interaction with PKC and cyclic nucleotide signaling. We will briefly discuss the emerging evidence that remodeling of cortical actin is necessary for contraction.