Validation of purdue engineering shape benchmark clusters by crowdsourcing

The effective organization of CAD data archives is central to PLM and consequently content based retrieval of 2D drawings and 3D models is often seen as a "holy grail" for the industry. Given this context, it is not surprising that the vision of a "Google for shape", which enables engineers to search databases of 3D models for components similar in shape to a query part, has motivated numerous researchers to investigate algorithms for computing geometric similarity. Measuring the effectiveness of the many approaches proposed has in turn lead to the creation of benchmark datasets against which researchers can compare the performance of their search engines. However to be useful the datasets used to measure the effectiveness of 3D retrieval algorithms must not only define a collection of models, but also provide a canonical specification of their relative similarity. Because the objective of shape retrieval algorithms is (typically) to retrieve groups of objects that humans perceive as "similar" these benchmark similarity relationships have (by definition) to be manually determined through inspection

Haematology and biochemical parameters of different feeding behaviour of teleost fishes from Vellar estuary, India

Haematological parameters have been recognized as valuable tools for monitoring fish health. Haematological and serum biochemical parameters were studied and compared different feeding behaviour of teleost fishes. Three marine teleost fishes, Lates calcarifer (carnivores), Mugil cephalus (omnivores) and Chanos chanos (herbivores), were carried out in order to find out a normal range of blood parameters which would serve as baseline data for assessment of the health status of the fish as well as reference point for future comparative surveys. Blood parameters such as red blood cell count (RBC) and white blood cells count (WBC), haemoglobin, haematocrit, mean cell haemoglobin concentration (MCHC), mean cell volume (MCV), mean cell haemoglobin, glucose, protein, cholesterol and urea were estimated from teleost fishes of different trophic level. Statistical analysis revealed that differences in haematological parameters between marine fish were significant (P<0.01)

Geometric reasoning via internet crowdsourcing

The ability to interpret and reason about shapes is a peculiarly human capability that has proven difficult to reproduce algorithmically. So despite the fact that geometric modeling technology has made significant advances in the representation, display and modification of shapes, there have only been incremental advances in geometric reasoning. For example, although today's CAD systems can confidently identify isolated cylindrical holes, they struggle with more ambiguous tasks such as the identification of partial symmetries or similarities in arbitrary geometries. Even well defined problems such as 2D shape nesting or 3D packing generally resist elegant solution and rely instead on brute force explorations of a subset of the many possible solutions. Identifying economic ways to solving such problems would result in significant productivity gains across a wide range of industrial applications. The authors hypothesize that Internet Crowdsourcing might provide a pragmatic way of removing many geometric reasoning bottlenecks.This paper reports the results of experiments conducted with Amazon's mTurk site and designed to determine the feasibility of using Internet Crowdsourcing to carry out geometric reasoning tasks as well as establish some benchmark data for the quality, speed and costs of using this approach.After describing the general architecture and terminology of the mTurk Crowdsourcing system, the paper details the implementation and results of the following three investigations; 1) the identification of "Canonical" viewpoints for individual shapes, 2) the quantification of "similarity" relationships with-in collections of 3D models and 3) the efficient packing of 2D Strips into rectangular areas. The paper concludes with a discussion of the possibilities and limitations of the approach

(Z)-4-{1-[(2-Hy­droxy­ethyl)­amino]­ethyl­idene}-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

In the title compound C14H17N3O2, the dihedral angle between the rings is 16.68 (13)°. Although the compound crystallizes in the keto form, the possibility of keto-enamine–enol-imine tautomerism is explained by a strong intra­molecular N—H⋯O hydrogen bond

Ethyl 7-oxo-3,5-diphenyl-1,4-diazepane-2-carboxyl­ate

The title compound, C20H22N2O3, crystallizes with two independent mol­ecules in the asymmetric unit. In both mol­ecules, the diazepane rings adopt chair conformations. The mean planes of the diazepane rings in the two molecules form dihedral angles of 71.6 (4)/40.3 (5) and 75.9 (5)/58.6 (7)° with the neighbouring benzene rings. The carbonyl-group O atoms deviate significantly from the diazepane rings, by 0.685 (14) and 0.498 (13) Å. The eth­oxy­carbonyl groups show conformational difference between two mol­ecules, as reflected in the orientation of the carbonyl O atoms and the C—C—O—C torsion angle of −179.0 (2)° in one mol­ecule and 73.2 (2)° in the other. In one molecule there is a short N—H⋯O contact that generates an S(5) ring motif. In the crystal, N—H⋯O inter­actions generate R 2 2(8) graph-set motifs and C—H⋯O inter­actions generate R 2 2(10) and R 2 2(14) graph-set motifs. C—H⋯π inter­actions also occur

The problem of programming language concurrency semantics

Despite decades of research, we do not have a satisfactory concurrency semantics for any general-purpose programming language that aims to support concurrent systems code. The Java Memory Model has been shown to be unsound with respect to standard compiler optimisations, while the C/C++11 model is too weak, admitting undesirable thin-air executions. Our goal in this paper is to articulate this major open problem as clearly as is currently possible, showing how it arises from the combination of multiprocessor relaxed-memory behaviour and the desire to accommodate current compiler optimisations. We make several novel contributions that each shed some light on the problem, constraining the possible solutions and identifying new difficulties. First we give a positive result, proving in HOL4 that the existing axiomatic model for C/C++11 guarantees sequentially consistent semantics for simple race-free programs that do not use low-level atomics (DRF-SC, one of the core design goals). We then describe the thin-air problem and show that it cannot be solved, without restricting current compiler optimisations, using any per-candidate-execution condition in the style of the C/C++11 model. Thin-air executions were thought to be confined to programs using relaxed atomics, but we further show that they recur when one attempts to integrate the concurrency model with more of C, mixing atomic and nonatomic accesses, and that also breaks the DRF-SC result. We then describe a semantics based on an explicit operational construction of out-of-order execution, giving the desired behaviour for thin-air examples but exposing further difficulties with accommodating existing compiler optimisations. Finally, we show that there are major difficulties integrating concurrency semantics with the C/C++ notion of undefined behaviour. We hope thereby to stimulate and enable research on this key issue

Ethyl 2-benzyl-3-[3-(4-chloro­phen­yl)-1-phenyl-1H-pyrazol-4-yl]-4,6-dioxo-5-phenyl­octa­hydro­pyrrolo­[3,4-c]pyrrole-1-carboxyl­ate

The title compound, C37H31ClN4O4, crystallizes with two mol­ecules (A and B) in the asymmetric unit. The pyrrole rings in both mol­ecules are connected via cis fusion, whereas one ring has a twisted conformation and the other assumes a half-chair conformation. In the crystal, the A mol­ecules form inversion dimers via a pair of C—H⋯Cl inter­actions, while the B mol­ecules form chains propagating in [10], via C—H⋯O inter­actions. In the crystal, there are also a number of C—H⋯π inter­actions present