bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexible Developable Surfaces
Authors: Solomon Justin , Vouga Etienne , Wardetzky Max , Grinspun Eitan 
Published: August 2012

AbstractWe introduce a discrete paradigm for developable surface modeling. Unlike previous attempts at interactive developable surface modeling, our system is able to enforce exact developability at every step, ensuring that users do not inadvertently suggest configurations that leave the manifold of admissible folds of a flat two‐dimensional sheet. With methods for navigation of this highly nonlinear constraint space in place, we show how to formulate a discrete mean curvature bending energy measuring how far a given discrete developable surface is from being flat. This energy enables relaxation of user‐generated configurations and suggests a straightforward subdivision scheme that produces admissible smoothed versions of bent regions of our discrete developable surfaces.
Microtiles: Extracting Building Blocks from Correspondences
Authors: Kalojanov Javor , Bokeloh Martin , Wand Michael , Guibas Leonidas , Seidel Hans‐Peter , Slusallek Philipp 
Published: August 2012

AbstractIn this paper, we develop a theoretical framework for characterizing shapes by building blocks. We address two questions: First, how do shape correspondences induce building blocks? For this, we introduce a new representation for structuring partial symmetries (partial self‐correspondences), which we call “microtiles”. Starting from input correspondences that form point‐wise equivalence relations, microtiles are obtained by grouping connected components of points that share the same set of symmetry transformations. The decomposition is unique, requires no parameters beyond the input correspondences, and encodes the partial symmetries of all subsets of the input. The second question is: What is the class of shapes that can be assembled from these building blocks? Here, we specifically consider r‐similarity as correspondence model, i.e., matching of local r‐neighborhoods. Our main result is that the microtiles of the partial r‐symmetries of an object S can build all objects that are (r+ε)‐similar to S for any ε >0. Again, the construction is unique. Furthermore, we give necessary conditions for a set of assembly rules for the pairwise connection of tiles. We describe a practical algorithm for computing microtile decompositions under rigid motions, a corresponding prototype implementation, and conduct a number of experiments to visualize the structural properties in practice.
Modeling Polyhedral Meshes with Affine Maps
Authors: Vaxman Amir 
Published: August 2012

AbstractWe offer a framework for editing and modeling of planar meshes, focusing on planar quad, and hexagonal‐dominant meshes, which are held in high demand in the field of architectural design. Our framework manipulates these meshes by affine maps that are assigned per‐face, and which naturally ensure the planarity of these faces throughout the process, resulting in a linear subspace of compatible planar deformations for any given mesh. Our modeling metaphors include classical handle‐based editing, mesh interpolation, and shape‐space exploration, all of which allow for an intuitive way to produce new polyhedral and near‐polyhedral meshes by editing.
Computing Extremal Quasiconformal Maps
Authors: Weber Ofir , Myles Ashish , Zorin Denis 
Published: August 2012

AbstractConformal maps are widely used in geometry processing applications. They are smooth, preserve angles, and are locally injective by construction. However, conformal maps do not allow for boundary positions to be prescribed. A natural extension to the space of conformal maps is the richer space of quasiconformal maps of bounded conformal distortion. Extremal quasiconformal maps, that is, maps minimizing the maximal conformal distortion, have a number of appealing properties making them a suitable candidate for geometry processing tasks. Similarly to conformal maps, they are guaranteed to be locally bijective; unlike conformal maps however, extremal quasiconformal maps have sufficient flexibility to allow for solution of boundary value problems. Moreover, in practically relevant cases, these solutions are guaranteed to exist, are unique and have an explicit characterization.We present an algorithm for computing piecewise linear approximations of extremal quasiconformal maps for genus‐zero surfaces with boundaries, based on Teichmüller's characterization of the dilatation of extremal maps using holomorphic quadratic differentials. We demonstrate that the algorithm closely approximates the maps when an explicit solution is available and exhibits good convergence properties for a variety of boundary conditions.
Growing Least Squares for the Analysis of Manifolds in Scale‐Space
Authors: Mellado Nicolas , Guennebaud Gaël , Barla Pascal , Reuter Patrick , Schlick Christophe 
Published: August 2012

AbstractWe present a novel approach to the multi‐scale analysis of point‐sampled manifolds of co‐dimension 1. It is based on a variant of Moving Least Squares, whereby the evolution of a geometric descriptor at increasing scales is used to locate pertinent locations in scale‐space, hence the name “Growing Least Squares”. Compared to existing scale‐space analysis methods, our approach is the first to provide a continuous solution in space and scale dimensions, without requiring any parametrization, connectivity or uniform sampling. An important implication is that we identify multiple pertinent scales for any point on a manifold, a property that had not yet been demonstrated in the literature. In practice, our approach exhibits an improved robustness to change of input, and is easily implemented in a parallel fashion on the GPU. We compare our method to state‐of‐the‐art scale‐space analysis techniques and illustrate its practical relevance in a few application scenarios.
Dihedral Angle Mesh Error: a fast perception correlated distortion measure for fixed connectivity triangle meshes
Authors: Váša Libor , Rus Jan 
Published: August 2012

AbstractIn computer graphics, triangle meshes are ubiquitous as a representation of surface models. Processing of this kind of data, such as compression or watermarking, often involves an unwanted distortion of the surface geometry. Advanced processing algorithms are continuously being proposed, aiming at improving performance (compression ratio, watermark robustness and capacity), while minimizing the introduced distortion.In most cases, the final resulting mesh is intended to be viewed by a human observer, and it is therefore necessary to minimise the amount of distortion perceived by the human visual system. However, only recently there have been studies published on subjective experiments in this field, showing that previously used objective error measures exhibit rather poor correlation with the results of subjective experiments.In this paper, we present results of our own large subjective testing aimed at human perception of triangle mesh distortion. We provide an independent confirmation of the previous result by Lavoué et al. that most current metrics perform poorly, with the exception of the MSDM/MSDM2 metrics. We propose a novel metric based on measuring the distortion of dihedral angles, which provides even higher correlation with the results of our experiments and experiments performed by other researchers. Our metric is about two orders of magnitude faster than MSDM/MSDM2, which makes it much more suitable for usage in iterative optimisation algorithms.
Stream Surface Parametrization by Flow‐Orthogonal Front Lines
Authors: Schulze Maik , Germer Tobias , Rössl Christian , Theisel Holger 
Published: August 2012

AbstractThe generation of discrete stream surfaces is an important and challenging task in scientific visualization, which can be considered a particular instance of geometric modeling. The quality of numerically integrated stream surfaces depends on a number of parameters that can be controlled locally, such as time step or distance of adjacent vertices on the front line. In addition there is a parameter that cannot be controlled locally: stream surface meshes tend to show high quality, well‐shaped elements only if the current front line is “globally” approximately perpendicular to the flow direction. We analyze the impact of this geometric property and present a novel solution – a stream surface integrator that forces the front line to be perpendicular to the flow and that generates quad‐dominant meshes with well‐shaped and well‐aligned elements. It is based on the integration of a scaled version of the flow field, and requires repeated minimization of an error functional along the current front line. We show that this leads to computing the 1‐dimensional kernel of a bidiagonal matrix: a linear problem that can be solved efficiently. We compare our method with existing stream surface integrators and apply it to a number of synthetic and real world data sets.
Fast and Robust Normal Estimation for Point Clouds with Sharp Features
Authors: Boulch Alexandre , Marlet Renaud 
Published: August 2012

AbstractThis paper presents a new method for estimating normals on unorganized point clouds that preserves sharp features. It is based on a robust version of the Randomized Hough Transform (RHT). We consider the filled Hough transform accumulator as an image of the discrete probability distribution of possible normals. The normals we estimate corresponds to the maximum of this distribution. We use a fixed‐size accumulator for speed, statistical exploration bounds for robustness, and randomized accumulators to prevent discretization effects. We also propose various sampling strategies to deal with anisotropy, as produced by laser scans due to differences of incidence. Our experiments show that our approach offers an ideal compromise between precision, speed, and robustness: it is at least as precise and noise‐resistant as state‐of‐the‐art methods that preserve sharp features, while being almost an order of magnitude faster. Besides, it can handle anisotropy with minor speed and precision losses.
The structure of acute stress disorder among Chinese adults exposed to an earthquake: Is dysphoric arousal a unique construct of acute posttraumatic responses?
Authors: WANG RICHU , WANG LI , ZHANG JIANXIN , LIU ZHENGKUI , WU KANKAN 
Published: August 2012

Wang, R., Wang, L., Zhang, J., Liu, Z. & Wu, K. (2012). The structure of acute stress disorder among Chinese adults exposed to an earthquake: Is dysphoric arousal a unique construct of acute posttraumatic responses? Scandinavian Journal of Psychology 53, 430–436.As a diagnosis organized mainly on the basis of theoretical conceptualization, acute stress disorder (ASD) has been widely criticized for lack of empirical support since it was introduced into the DSM system. To address this issue, the present study investigated the latent structure of ASD symptoms measured by the Acute Stress Disorder Scale (ASDS). A total of 350 adults with a mean age of 32.9 years (SD = 14.0, range: 16–85) took part in this study 12 to 15 days after an earthquake. The results of confirmatory factor analyses showed that a five‐factor intercorrelated model (dissociation, reexperiencing, avoidance, dysphoric arousal, and anxious arousal) demonstrated the best data fit. The findings provide preliminary empirical evidence in favor of a new reconceptualization of ASD symptoms, and are informative for the impending DSM‐5.
Estimating Consistent Border Effects in Gravity Models with Multilateral Resistance
Authors: Egger Peter H. , Larch Mario 
Published: August 2012

AbstractWe suggest a modification of the Anderson and van Wincoop gravity model that relies on trade friction parameter estimates that are robust to the correlation of trade friction variables with any country‐specific unobservable variables. This leads to significantly different US–Canadian border effects as compared to the original approach.
The power of unit root tests against nonlinear local alternatives
Authors: Demetrescu Matei , Kruse Robinson 
Published: August 2012

This article extends the analysis of local power of unit root tests in a nonlinear direction by considering local nonlinear alternatives and tests built specifically against stationary nonlinear models. In particular, we focus on the popular test proposed by Kapetanioset al.(2003, Journal of Econometrics 112, 359–379) in comparison to the linear Dickey–Fuller test. To this end, we consider different adjustment schemes for deterministic terms. We provide asymptotic results which imply that the error variance has a severe impact on the behaviour of the tests in the nonlinear case; the reason for such behaviour is the interplay of non‐stationarity and nonlinearity. In particular, we show that nonlinearity of the data generating process can be asymptotically negligible when the error variance is moderate or large (compared to the ‘amount of nonlinearity’), rendering the linear test more powerful than the nonlinear one. Should however the error variance be small, the nonlinear test has better power against local alternatives. We illustrate this in an asymptotic framework of what we call persistent nonlinearity. The theoretical findings of this article explain previous results in the literature obtained by simulation. Furthermore, our own simulation results suggest that the user‐specified adjustment scheme for deterministic components (e.g. OLS, GLS, or recursive adjustment) has a much higher impact on the power of unit root tests than accounting for nonlinearity, at least under local (linear or nonlinear) alternatives.
Rehabilitating Social Conflicts in European Public Law
Authors: Dani Marco 
Published: August 2012

AbstractSubject to conditions that public law can secure, social conflicts can be normatively appealing for their dividend in terms of dynamism, identity and stability. While this notion was key to post‐World War II European public law, it no longer holds true now that social conflicts are increasingly marginalised by the expansion of supranational law and its consensus culture. However, far from disappearing social conflicts re‐emerge as challenges to the current institutional setting, even despite the policy of constitutional gesture undertaken by EU institutions. This paper tracks the role of social conflicts in European public law and argues that as long as EU politics fails to embrace a culture of social conflicts, challenges to the authority of EU law can be normatively justified.
Reconfiguring the Politics–Law Relationship in the Integration Project through Conflicts–Law Constitutionalism
Authors: Everson Michelle , Joerges Christian 
Published: August 2012

AbstractThis paper argues that the relationship between law and politics must be reconfigured within the European Union. Dissecting recent crises in economic, social and political organisation within Europe with reference to the three ‘fictitious’ commodities of Karl Polanyi, we find that law in Europe has contributed to de‐legalisation, de‐socialisation and disenfranchisement. Moving on to review the potential for law to respond to crisis through new paradigms of conflict resolution as suggested by Ralf Dahrendorf, we find that the steering capacity of law is nevertheless limited if it fails to establish a sustaining relationship with politics. Our conclusions are modest: conflict–law constitutionalism cannot solve Europe's many crises. However, it does represent a new paradigm of law within which relations between European law and European politics might be re‐established—a vital step to overcoming crisis.
From Workers to Migrants, from Distributive Justice to Inclusion: Exploring the Changing Social Democratic Imagination
Authors: Somek Alexander 
Published: August 2012

Abstract:There is little awareness that from the perspective of distributive justice, a transnational market society exercises a justice‐disabling effect. No longer is society perceived to be a system of co‐operation, the net product of which is to be distributed among all participants fairly, but rather viewed as a composite of uncoordinated templates for the individual pursuit of opportunities. A society of this type does no longer regard a centralised political effort at redistribution as its essential objective; rather, its most fundamental principle concerns equal access to opportunities without regard to nationality or local preference. Such a concern with inclusion appears to be at odds with the received vision of distributive justice whose realisation presupposes bounded solidarity and, hence, closure.
Assessment of methotrexate hepatotoxicity in psoriasis patients: a prospective evaluation of four serum fibrosis markers
Authors: Chládek J. , S̆imková M. , Vanec̆ková J. , Hroch M. , Vávrová J. , Hůlek P. 
Published: August 2012

AbstractBackground  Low‐dose oral methotrexate (MTX) is an effective immunosuppressive therapy for chronic plaque psoriasis. However, its use is hampered by the risk of liver fibrosis.Aim  To compare the results of serial measurements of serum fibrosis markers during the remission‐induction phase of treatment with MTX to those of patients on biological therapy and long‐term MTX therapy (>2 years).Subjects and methods  Serum concentrations of hyaluronic acid, N‐terminal propeptide of collagen type III (PIIINP) and the results of two multi‐test algorithms Fibrotest and Hepascore were evaluated in patients with chronic plaque psoriasis (N = 24, age: 28–79 years, baseline Psoriasis Area Severity Index PASI 13.5, range 2.2–33) at baseline and weeks 16 and 26 after the start of pharmacokinetically guided therapy with MTX (Group A). Patients on established therapy with biologics (N = 15, Group B) and long‐term MTX users (N = 10, Group C) with the mean baseline PASI scores of 0.9 and 1.2 were studied in parallel cohorts.Results  At baseline, HA, Hepascore and PIIINP were correlated with PASI of Group A patients. At weeks 16 and 26, HA decreased by 48% and 40% (P < 0.001) and Hepascore by 31 (P < 0.01) and 20% (P < 0.05) respectively. PASI75 (≥75% improvement from baseline PASI) was observed in 76% of Group A patients by week 26 and the absolute decreases in PASI and both fibrosis markers were correlated (HA: r = 0.49, P = 0.018, Hepascore: r = 0.47, P = 0.022). In contrast, no significant within‐group differences were found in HA and Hepascore results of patients in the groups B and C. PIIINP and Fibrotest were stable in all groups.Conclusion  The fibrosis markers hyaluronic acid and Hepascore (the multiple test algorithm which includes hyaluronic acid) are less liver specific and more prone to reflect psoriasis activity than PIIINP and Fibrotest.
Increased number of circulating endothelial cells (CECs) in patients with psoriasis ‐ preliminary report
Authors: Batycka‐Baran A. , Paprocka M. , Krawczenko A. , Duś D. , Szepietowski J.C. 
Published: August 2012

AbstractBackground  Numerous studies have demonstrated increased cardiovascular risk in psoriasis. Circulating endothelial cells (CECs) have been proposed as a new marker of endothelial dysfunction that plays an important role in pathogenesis of atherosclerosis.Objective  The aim of this study was to compare the number of CECs in psoriatic patients to a control group and to analyze possible correlations between the numbers of CECs and the plasma levels of classical markers of endothelial dysfunction, such as: sICAM‐1, sE‐selectin and von Willebrand factor (vWF).Methods  The number of CECs, identified as CD146 + / CD45‐ cells, were determined in peripheral blood with using flow cytometry in psoriatic patients (n = 63) and controls (n = 31). The plasma levels of: sICAM‐1, sE‐selectin, vWF were measured with ELISA. The severity of psoriasis was assessed with PASI.Results  The number of CECs was significantly increased in psoriatic patients compared with controls (P < 0.00001) and positively correlated with disease severity (R = 0.360; P = 0.0037). The levels of sICAM‐1, sE‐selectin and vWF were significantly elevated in psoriatic patients (P < 0.00001; P < 0.00001; P = 0.00072, respectively). The number of CECs was significantly, positively correlated with the levels of sICAM‐1 (R = 0.393; P = 0.0014) and vWF (R = 0.314; P = 0.012) in psoriatic patients. The levels of sICAM‐1 and sE‐selectin were positively correlated with disease severity (R = 0.356; P = 0.0041 and R = 0.407; P = 0.0009, respectively).Conclusion  The increased number of CECs that correlates with disease severity and plasma levels of sICAM‐1 and vWF may indicate endothelial dysfunction or injury in patients with psoriasis.
Pitted keratolysis; physicians’ treatment and their perceptions in Dutch army personnel
Authors: van der Snoek E.M. , Ekkelenkamp M.B. , Suykerbuyk J.C.C.W. 
Published: August 2012

AbstractBackground  Pitted keratolysis (PK) is a common plantar skin manifestation in army personnel, farmers and athletes. Due to pain while walking and marching, the condition can cause reduced operational deployability (in case of army personnel).Objective  We used a questionnaire to investigate currently used treatment options of PK and perceptions on perceived efficacy of these treatments among Royal Netherlands Armed Forces primary health care physicians.Methods  A cross‐sectional anonymous postal questionnaire survey was conducted among all Royal Netherlands Armed Forces primary health care physicians. In addition to question about prescription behaviour on the treatment of PK by topical and oral therapies and given non‐pharmacological treatment, several questions assessed perceived efficacy of these therapies.Results  Of the 164 eligible primary health care physicians, 51 (31.1%) completed the questionnaire. Half of physicians had seen less than five patients with PK in the preceding year. Two‐thirds of physicians reported problems with operational deployability in less than 10% of army personnel with PK. PK was treated mostly with topical and non‐pharmacological treatments. Oral therapy was seldom prescribed. For hyperhidrosis, aluminium chloride hexahydrate was used in most cases.Conclusion  PK and related reduced operational deployability were less often reported than expected in this study. Dutch physicians prefer combined topical antibiotic therapy with non‐pharmacological treatments and perceive the efficacy of topical antibiotic therapy superior to non‐pharmacological treatments. Preventive measures, topical antibiotic therapy and adequate treatment of hyperhidrosis are the mainstay methods in the management of patients with PK.
Angiotensinogen Gene M235T and T174M Polymorphisms and Susceptibility of Pre‐Eclampsia: A Meta‐Analysis
Authors: Lin Rong , Lei Yunping , Yuan Ziyu , Ju Hongfang , Li Dongna 
Published: August 2012

SummaryThere are controversies in reports on the association of the angiotensinogen (AGT) gene polymorphisms with the risk of developing pre‐eclampsia (PE). We performed a meta‐analysis to examine the association between the AGT polymorphisms and PE risk: M235T (31 studies involving 2555 patients and 6114 controls) and T174M (six studies involving 681 patients and 2076 controls). For the M235T polymorphism, the TT genotype increased the PE risk as compared to the MM genotype (odds ratio 1.61, 95% confidence intervals 1.22–2.14, P= 0.001). When stratified by ethnicity, the TT genotype remained significantly associated with higher PE risk in Caucasians and Mongolians but not in Africans. Similar results were also obtained under all three genetic models of the M235T polymorphism. For the T174M polymorphism, no significant association was found in the comparisons (MT vs. TT and MM vs. TT) and under any genetic models. The analysis excluding the highly significant Hardy–Weinberg equilibrium‐violating studies and sensitivity analysis further strengthened the validity of these associations. No publication bias was observed in this study. This meta‐analysis demonstrates that the AGT M235T polymorphism is significantly associated with PE whereas the T174M polymorphism is not.