Satisfiability Modulo Transcendental Functions via Incremental Linearization

In this paper we present an abstraction-refinement approach to Satisfiability Modulo the theory of transcendental functions, such as exponentiation and trigonometric functions. The transcendental functions are represented as uninterpreted in the abstract space, which is described in terms of the combined theory of linear arithmetic on the rationals with uninterpreted functions, and are incrementally axiomatized by means of upper- and lower-bounding piecewise-linear functions. Suitable numerical techniques are used to ensure that the abstractions of the transcendental functions are sound even in presence of irrationals. Our experimental evaluation on benchmarks from verification and mathematics demonstrates the potential of our approach, showing that it compares favorably with delta-satisfiability /interval propagation and methods based on theorem proving

Optimisation of build orientation to achieve minimum environmental impact in Stereo-lithography

Abstract Additive Manufacturing includes a number of techniques that combine a specific equipment with certain materials but some common principles concerning the product design and aspects related to manufacturing optimisations can be identified. Amongst these principles, some process parameters are included that contribute to determining the environmental sustainability of engineering products and, in particular, that affect their Life Cycle Impact Assessment. This paper aims to provide a method to find out build orientation for the additive stereo-lithography process by minimising the environmental impact. More precisely, environmental indicators related to product design, materials and machines are included and combined in order to estimate the process time and the volume of needed supports. Besides, Genetic Algorithms have been used to find out the product orientation that optimises the manufacturing process in terms of quantity and volume of used material, thus minimizing its environmental impact. The proposed method has been implemented by a new software application that is presented in a nutshell

The evolution of early-type galaxies at z~1 from the K20 survey

We have performed VLT spectroscopy of an almost complete sample of 18 early-type galaxies with 0.88 < z < 1.3 plus two at z=0.67, selected from the K20 survey, and derived the velocity dispersion for 15+2 of them. By combining these data with HST and VLT images, we study the Fundamental Plane (FP), the Faber-Jackson and the Kormendy relations at z~1, and compare them with the local ones. The FP at z~1 keeps a remarkably small scatter, and shows both an offset and a rotation, which we interpret in terms of evolution of the mass-to-light ratio, and possibly of the size. We show evidence that the evolution rate depends on galaxy mass, being faster for less massive galaxies. We discuss the possible factors driving the evolution of spheroids and compare our results with the predictions of the hierachical models of galaxy formation.Comment: 14 pages, 15 figures, accepted by A&

Evaluation of Competencies for a Sustainable Industrial Environment

The organisation of worker activities in manufacturing shops have been differently conceived depending on political, societal, environmental and economic circumstances affecting industrial development. From Taylorism and Fordism through Lean Manufacturing to the innovative Cell Production system, the level and quality of abilities and competencies of workers have increasingly become the kernel of factory management models. Sustainability has increasingly become a crucial factor for product success. The design and manufacture of industrial products are conceived in circular loops within the 6R framework. The digitalisation of information has allowed significant advancements. Qualified and skilled operators have accompanied and led these evolutions, and their abilities and creativity have grown relevant, despite the continuous increase in automation. This work investigates the contribution of craftsmanship abilities in the industrial environment. For this purpose, the Craftsmanship Index has been proposed to assign a quantitative value to the craftsmanship skills contributing to the manufacturing activities. A customised questionnaire to be administered to workers is used to calculate this index, which is helpful to analyse worker abilities and the way they are learned and developed, being part of effective management and decision-making tools. A case study in the Japanese manufacturing environment expands on previous results achieved in Italy. The Craftsmanship Index allowed us to give a quantitative relevance to the level of abilities of operators depending on the analysed department. Some cultural differences have also emerged thanks to the comparison between the Japanese and the Italian culture

Model Checking a C++ Software Framework, a Case Study

This paper presents a case study on applying two model checkers, SPIN and DIVINE, to verify key properties of a C++ software framework, known as ADAPRO, originally developed at CERN. SPIN was used for verifying properties on the design level. DIVINE was used for verifying simple test applications that interacted with the implementation. Both model checkers were found to have their own respective sets of pros and cons, but the overall experience was positive. Because both model checkers were used in a complementary manner, they provided valuable new insights into the framework, which would arguably have been hard to gain by traditional testing and analysis tools only. Translating the C++ source code into the modeling language of the SPIN model checker helped to find flaws in the original design. With DIVINE, defects were found in parts of the code base that had already been subject to hundreds of hours of unit tests, integration tests, and acceptance tests. Most importantly, model checking was found to be easy to integrate into the workflow of the software project and bring added value, not only as verification, but also validation methodology. Therefore, using model checking for developing library-level code seems realistic and worth the effort.Comment: In Proceedings of the 27th ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE '19), August 26-30, 2019, Tallinn, Estonia. ACM, New York, NY, USA, 11 page

Understanding Transdisciplinary Engineering in Public Policy: A Survey of Policy Actors' Perceptions of Engineering Expertise

The transdisciplinary engineering project aims to transform the practice of engineering for more social benefit, and be agenda driven. For this to work, a key community of non-engineering actors needs to be effectively engaged: those working in public policy. Through data gathered for a project exploring interested in a career development scheme for policy officials offered by the UK's Royal Academy of Engineering, we explore the opportunities and barriers to better engagement between engineering and this community. An explorative online survey with policy actors gathered views on the importance of (non-transdisciplinary) engineering to policy in different policy settings. While those who regard technical expertise as crucial to their policy are keen to engage with engineering, others find it more difficult to engage. We suggest this is down to three factors: narrowness in what ‘engineering' is (so a failure to understand the ability to apply engineering concepts, e.g. systems thinking, in a variety of areas); organisational arrangements that split policy practice that might more readily connect to engineering from those who do policy design; policy analysis rooted in standard microeconomic forms of analysis. We suggest ways in which these issues might be addressed through education and research to enable the effective deployment of transdisciplinary engineering practice

B3 0003+387: AGN Marked Large-Scale Structure at z=1.47?

We present evidence for a significant overdensity of red galaxies, as much as a factor of 14 over comparable field samples, in the field of the z=1.47 radio galaxy B3 0003+387. The colors and luminosities of the brightest red galaxies are consistent with their being at z>0.8. The radio galaxy and one of the red galaxies are separated by 5" and show some evidence of a possible interaction. However, the red galaxies do not show any strong clustering around the radio galaxy nor around any of the brighter red galaxies. The data suggest that we are looking at a wall or sheet of galaxies, possibly associated with the radio galaxy at z=1.47. Spectroscopic redshifts of these red galaxies will be necessary to confirm this large-scale structure.Comment: 19 pages, 7 figures, LaTeX2e/AASTeX v5.0.2. The full photometric catalog is included as a separate deluxetable file. To appear in the Astronomical Journal (~Nov 00

Measuring the Virial Temperature of Galactic Halos Through Electron Scattering of Quasar Emission Lines

Semi-analytic models of galaxy formation postulate the existence of virialized gaseous halos around galaxies at high redshifts. A small fraction of the light emitted by any high-redshift quasar is therefore expected to scatter off the free electrons in the halo of its host galaxy. The broadening of the scattered emission lines of the quasar can be used to measure the temperature of these electrons. For gas in virial equilibrium, the velocity width of the scattered line profile is larger by a factor of (m_p/m_e)^{1/2}=43 than the velocity dispersion of the host galaxy and reaches >10,000 km/s for the massive galaxies and groups in which bright quasars reside. In these systems, the scattered width exceeds the intrinsic width of the quasar lines and hence can be used to measure the virial temperature of the quasar host. The high degree of polarization of the scattered radiation can help filter out the extended scattered light from the central emission by the quasar and its host galaxy. The signal-to-noise ratio of the spectral broadening can be enhanced by matching the full spectrum of the scattered radiation to a template of the unscattered quasar spectrum. Although the central fuzz around low-redshift quasars is dominated by starlight, the fuzz around high-redshift quasars might be dominated by scattering before galaxies have converted most of their gas reservoirs into stars.Comment: 10 pages, 1 figures, submitted to ApJ Letter

Splitting Proofs for Interpolation

We study interpolant extraction from local first-order refutations. We present a new theoretical perspective on interpolation based on clearly separating the condition on logical strength of the formula from the requirement on the com- mon signature. This allows us to highlight the space of all interpolants that can be extracted from a refutation as a space of simple choices on how to split the refuta- tion into two parts. We use this new insight to develop an algorithm for extracting interpolants which are linear in the size of the input refutation and can be further optimized using metrics such as number of non-logical symbols or quantifiers. We implemented the new algorithm in first-order theorem prover VAMPIRE and evaluated it on a large number of examples coming from the first-order proving community. Our experiments give practical evidence that our work improves the state-of-the-art in first-order interpolation.Comment: 26th Conference on Automated Deduction, 201

Very Red and Extremely Red Galaxies in the Fields of z ~ 1.5 Radio-Loud Quasars

We previously identified an excess of mostly red galaxies around 31 RLQs at z=1-2. These fields have an ERO (extremely red object, R-K>6) density 2.7 times higher than the field. Assuming the EROs are passively evolved galaxies at the quasar redshifts, they have characteristic luminosities of only ~L^*. We also present new observations of four z~1.54 RLQ fields: (1) Wide-field J & Ks data confirm an Abell richness ~2 excess within 140" of Q0835+580 but an excess only within 50" of Q1126+101. (2) In 3 fields we present deep narrow-band redshifted H-alpha observations. We detect five candidate galaxies at the quasar redshifts, a surface density 2.5x higher than the field. (3) SCUBA sub-mm observations of 3 fields detect 2 quasars and 2 galaxies with SEDs best fit as highly reddened galaxies at the quasar z. (4) H-band adaptive optics (AO) imaging is used to estimate redshifts for 2 red, bulge-dominated galaxies using the Kormendy relation. Both have structural redshifts foreground to the quasar, but these are not confirmed by photometric redshifts, possibly because their optical photometry is corrupted by scattered light from the AO guidestar. (5) We use quantitative SED fits to constrain the photometric redshifts z_ph for some galaxies. Most galaxies near Q0835+580 are consistent with being at its redshift, including a candidate very old passively evolving galaxy. Many very & extremely red objects have z_ph z_q, and dust reddening is required to fit most of them, including many objects whose fits also require relatively old stellar populations. Large reddenings of E(B-V)~0.6 are required to fit four J-K selected EROs, though all but one of them have best-fit z_ph>z_q. These objects may represent a population of dusty high-z galaxies underrepresented in optically selected samples. (Abridged)Comment: Missing object 1126.424 added to Table 4; title changed to save people the apparent trouble of reading the abstract. 38 pages, 16 figures, 2 in color; all-PostScript figure version available from http://astro.princeton.edu/~pathall/tp3.ps.g