An Algebra of Pure Quantum Programming

We develop a sound and complete equational theory for the functional quantum programming language QML. The soundness and completeness of the theory are with respect to the previously-developed denotational semantics of QML. The completeness proof also gives rise to a normalisation algorithm following the normalisation by evaluation approach. The current work focuses on the pure fragment of QML omitting measurements.Comment: To appear in ENTCS, 3rd International Workshop on Quantum Programming Languages, 2005. 21 Page

Sulfonic acid coating of refractory sand for three-dimensional printing applications

Abstract: Rapid sand casting processes by additive manufacturing are predominantly based on furfuryl alcohol resin bonded sand catalysed with sulfonic acid. The prior coating of the refractory sand with sulfonic acid is a crucial process to ensure the suitability of the sand for threedimensional printing applications. The present paper investigated the sulfonic acid coating process of a local silica sand, which was found to have potential for three-dimensional printing applications in previous studies. Experimental conditions included sulfonic acid catalyst addition and mixing time. Coated sand was assessed for flowability and mechanical properties of test specimens produced by three-dimensional printing using a Voxeljet VX 1000. The optimum catalyst addition ranged between 0.3 and 0.6% yielding to transverse strength in the order of 110 to 165 KN/m2 and tensile strength ranging from 710 to 770 KN/m2

Coordinate-invariant Path Integral Methods in Conformal Field Theory

We present a coordinate-invariant approach, based on a Pauli-Villars measure, to the definition of the path integral in two-dimensional conformal field theory. We discuss some advantages of this approach compared to the operator formalism and alternative path integral approaches. We show that our path integral measure is invariant under conformal transformations and field reparametrizations, in contrast to the measure used in the Fujikawa calculation, and we show the agreement, despite different origins, of the conformal anomaly in the two approaches. The natural energy-momentum in the Pauli-Villars approach is a true coordinate-invariant tensor quantity, and we discuss its nontrivial relationship to the corresponding non-tensor object arising in the operator formalism, thus providing a novel explanation within a path integral context for the anomalous Ward identities of the latter. We provide a direct calculation of the nontrivial contact terms arising in expectation values of certain energy-momentum products, and we use these to perform a simple consistency check confirming the validity of the change of variables formula for the path integral. Finally, we review the relationship between the conformal anomaly and the energy-momentum two-point functions in our formalism.Comment: Corrected minor typos. To appear in International Journal of Modern Physics

Worldsheet Covariant Path Integral Quantization of Strings

We discuss a covariant functional integral approach to the quantization of the bosonic string. In contrast to approaches relying on non-covariant operator regularizations, interesting operators here are true tensor objects with classical transformation laws, even on target spaces where the theory has a Weyl anomaly. Since no implicit non-covariant gauge choices are involved in the definition of the operators, the anomaly is clearly separated from the issue of operator renormalization and can be understood in isolation, instead of infecting the latter as in other approaches. Our method is of wider applicability to covariant theories that are not Weyl invariant, but where covariant tensor operators are desired. After constructing covariantly regularized vertex operators, we define a class of background-independent path integral measures suitable for string quantization. We show how gauge invariance of the path integral implies the usual physical state conditions in a very conceptually clean way. We then discuss the construction of the BRST action from first principles, obtaining some interesting caveats relating to its general covariance. In our approach, the expected BRST related anomalies are encoded somewhat differently from other approaches. We conclude with an unusual but amusing derivation of the value $D= 26$ of the critical dimension.Comment: 64 pages, minor edits in expositio

PRF: A Framework for Building Automatic Program Repair Prototypes for JVM-Based Languages

PRF is a Java-based framework that allows researchers to build prototypes of test-based generate-and-validate automatic program repair techniques for JVM languages by simply extending it with their patch generation plugins. The framework also provides other useful components for constructing automatic program repair tools, e.g., a fault localization component that provides spectrum-based fault localization information at different levels of granularity, a configurable and safe patch validation component that is 11+X faster than vanilla testing, and a customizable post-processing component to generate fix reports. A demo video of PRF is available at https://bit.ly/3ehduSS.Comment: Proceedings of the 28th ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE '20

Determining the effect of three- dimensional printing orientation on the bending strength of sand moulds and cores when using a voxeljet additive manufacturing machine

Abstract: Advances made in Additive Manufacturing (AM) or 3D printing led to the 3D printing of sand moulds and cores used in the foundry industry. Ideally, the mechanical properties of the 3D printed moulds and cores should be uniform throughout the 3D printed part. This will ensure that the casting produced from the 3D printed mould has uniform properties throughout the mould. The following study investigated the effect of the printing location and part orientation in the AM machine used to produce the 3D Printed mould on the bending strength property of sand parts. Several printing orientations and angles were considered in the investigation. Descriptive statistics was used to assess and interpret the results

Mid-upper arm circumference (MUAC) as a feasible tool in detecting adult malnutrition

Objectives: This study aimed to expand on the limited South African malnutrition prevalence data and investigate the feasibility of mid-upper-arm circumference (MUAC) as a malnutrition screening tool. Design: A cross-sectional, multi-centre, descriptive design was adopted. Setting: The study was undertaken in three tertiary public hospitals in the same urban area within the Eastern Cape of South Africa. Subjects: Adult hospitalised patients volunteered to participate (n = 266). Methods: Data were collected using interviewer-administered questionnaires; obtaining anthropometric measurements; and consulting medical files. For maximum accuracy of various MUAC cut-off points, receiver operating characteristic curves were generated and area under the curve determined. Results: Both body mass index (BMI) and MUAC identified 21% of participants as underweight or malnourished, and 39% as overweight or obese. The Malnutrition Universal Screening Tool (MUST) found 23% at increased malnutrition risk. Nurses or doctors detected and referred only 19% of underweight patients (BMI < 18.5 kg/m2), to dietetics services. Direct measurements of BMI and MUST were unobtainable in 38% and 43% of patients respectively, whilst MUAC was obtainable in 100%. A statistically significant relationship (p < 0.001) exists between MUAC, BMI and MUST to detect malnutrition or malnutrition risk. MUAC cut-offs for undernutrition were determined at < 23 cm (BMI < 16 kg/m2) and < 24 cm (BMI < 18.5 kg/m2), respectively, for the study’s population groups. Conclusion: Malnutrition prevalence was high in this study, but often unidentified, with only a fifth referred to dietetic services. MUAC is a feasible method to identify adult malnutrition and should be considered as a malnutrition screening tool and key nutritional status indicator in South African public hospitals

First extraction of inclusive Vcb_{cb} from q2^{2} moments

We present the first determination of Vcb from inclusive B→Xcℓv¯¯¯ℓ using moments of the dilepton invariant mass, q2. These moments are reparametrization invariant quantities and depend on a reduced set of non-perturbative parameters. This reduced set of parameters opens a new path to extract these parameters up to 1/m4b purely from data and can potentially reduce the uncertainty on Vcb. In this paper, we present our first determination of Vcb using this method. Combining the recent measurements of q2 moments by Belle and Belle II, our default fit gives |Vcb| = (41.69±0.63)·10−3. This result presents an important independent cross check of, and is consistent with, the previous state-of-the-art inclusive determinations using lepton energy and hadronic invariant mass moments

The superfield quantisation of a superparticle action with an extended line element

A massive superparticle action based on the generalised line element in N = 1 global superspace is quantised canonically. A previous method of quantising this action, based on a Fock space analysis, showed that states existed in three supersymmetric multiplets, each of a different mass. The quantisation procedure presented uses the single first class constraint as an operator condition on a general N = 1 superwavefunction. The constraint produces coupled equations of motion for the component wavefunctions. Transformations of the component wavefunctions are derived that decouple the equations of motion and partition the resulting wavefunctions into three separate supermultiplets. Unlike previous quantisations of superparticle actions in N = 1 global superspace, the spinor wavefunctions satisfy the Dirac equation and the vector wavefunctions satisfy the Proca equation. The off-shell closure of the commutators of the supersymmetry transformations, that include mass parameters, are derived by the introduction of auxiliary wavefunctions. To avoid the ghosts arising in a previous Fock space quantisation an alternative conjugation is used in the definition of the current, based on a Krein space approach

A 3D track finder for the Belle II CDC L1 trigger

Machine learning methods are integrated into the pipelined first level (L1) track trigger of the upgraded flavor physics experiment Belle II at KEK in Tsukuba, Japan. The novel triggering techniques cope with the severe background from events outside the small collision region provided by the new SuperKEKB asymmetric-energy electron-positron collider. Using the precise drift-time information of the central drift chamber which provides axial and stereo wire layers, a neural network L1 trigger estimates the 3D track parameters of tracks, based on input from the axial wire planes provided by a 2D track finder. An extension of this 2D Hough track finder to a 3D finder is proposed, where the single hit representations in the Hough plane are trained using Monte Carlo. This 3D finder improves the track finding efficiency by including the stereo sense wires as input. The estimated polar track angle allows a specialization of the subsequent neural networks to sectors in the polar angle