Evaluating the Usability of the Glasgow Online Hypertext

Although there are many hypertext systems currently on the market there is little advice available on how authors can create easy-to-use hypertexts. This paper addresses the usability of Glasgow Online — a hypertext which contains tourist information on the city of Glasgow. The issues raised in the paper are based on an observational study in which a number of readers performed tasks representative of those undertaken by tourists visiting Glasgow. The usability issues raised by Glasgow Online are discussed in a wider context and their applicability to other styles of hypertext is considered.     

Mobile HCI 2004: Experience and Reflection

Mobile HCI is rapidly becoming one of the prime conferences on human-computer interaction with mobile technology. Its sixth edition took place on 13-16 September in Glasgow, where it originated in 1998. The conference, chaired by Mark Dunlop (University of Strathclyde) and Stephen Brewster (Glasgow University), gathered a heterogeneous group of academics and practitioners that has acquired a unique identity over the past five years. This year's contributions highlighted four research areas: evaluation methods and techniques, context-adaptive systems (including user adaptation, location technology, and power management), the tension between experience and reflection, and interaction styles (auditory, small-display presentation, tilt and touch input, and text entry).     

Compiling Vector Pascal to the XeonPhi

Intel's XeonPhi is a highly parallel x86 architecture chip made by Intel. It has a number of novel features which make it a particularly challenging target for the compiler writer. This paper describes the techniques used to port the Glasgow Vector Pascal Compiler to this architecture and assess its performance by comparisons of the XeonPhi with 3 other machines running the same algorithms. Copyright © 2015 John Wiley & Sons, Ltd.     

turboTDDFT – A code for the simulation of molecular spectra using the Liouville–Lanczos approach to time-dependent density-functional perturbation theory

We introduce turboTDDFT, an implementation of the Liouville–Lanczos approach to linearized time-dependent density-functional theory, designed to simulate the optical spectra of molecular systems made of up to several hundred atoms. turboTDDFT is open-source software distributed under the terms of the GPL as a component of Quantum ESPRESSO. As with other components, turboTDDFT is optimized to run on a variety of different platforms, from laptops to massively parallel architectures, using native mathematical libraries (LAPACK and FFTW) and a hierarchy of custom parallelization layers built on top of MPI.

Program summary

Program title: turboTDDFTCatalogue identifier: AEIX_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIX_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: GNU General Public License V 2.0No. of lines in distributed program, including test data, etc.: 3 559 889No. of bytes in distributed program, including test data, etc.: 254 283 981Distribution format: tar.gzProgramming language: Fortran 95Computer: Any computer architectureOperating system: GNU/Linux, AIX, IRIX, Mac OS X, and other UNIX-like OS?sClassification: 16.2, 16.6, 7.7External routines: turboTDDFT is a tightly integrated component of the Quantum ESPRESSO distribution and requires the standard libraries linked by it: BLAS, LAPACK, FFTW, MPI.Nature of problem: Calculation of the optical absorption spectra of molecular systems.Solution method: The dynamical polarizability of a system is expressed in terms of the resolvent of its Liouvillian super-operator within time-dependent density-functional theory, and calculated using a non-Hermitean Lanczos method, whose implementation does not require the calculation of any virtual states. Pseudopotentials (both norm-conserving and ultrasoft) are used in conjunction with plane-wave basis sets.Restrictions: Spin-restricted formalism. Linear-response regime. No hybrid functionals. Adiabatic XC kernels only.Unusual features: No virtual orbitals are used, nor even calculated. A single Lanczos recursion gives access to the whole optical spectrum.Additional comments: !!!!! The distribution file for this program is over 254 Mbytes and therefore is not delivered directly when download or E-mail is requested. Instead a html file giving details of how the program can be obtained is sent.Running time: From a few minutes for small molecules on serial machines up to many hours on multiple processors for complex nanosystems with hundreds of atoms.     

HidSecSOFTSUSY: Incorporating effects from hidden sectors in the numerical computation of the MSSM spectrum

SOFTSUSY is a software designed to solve the RG equations of the MSSM and compute its low energy spectrum. HidSecSOFTSUSY is an extension of the SOFTSUSY package which modifies the beta functions to include contributions from light dynamic fields in the hidden sector.

Program summary

Program title: HidSecSOFTSUSYCatalogue identifier: AEHP_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHP_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 4167No. of bytes in distributed program, including test data, etc.: 141 411Distribution format: tar.gzProgramming language: C++, FortranComputer: Personal computerOperating system: Tested on GNU/LinuxWord size: 32 bitsClassification: 11.6External routines: Requires an installed version of SOFTSUSY (http://projects.hepforge.org/softsusy/)Nature of problem: Calculating supersymmetric particle spectrum and mixing parameters while incorporating dynamic modes from the hidden sector into the renormalization group equations. The solution to the equations must be consistent with a high-scale boundary condition on supersymmetry breaking parameters, as well as a weak-scale boundary condition on gauge couplings, Yukawa couplings and the Higgs potential parameters.Solution method: Nested iterative algorithm.Running time: A few seconds per parameter point.     

Numeric and symbolic evaluation of the pfaffian of general skew-symmetric matrices

Evaluation of pfaffians arises in a number of physics applications, and for some of them a direct method is preferable to using the determinantal formula. We discuss two methods for the numerical evaluation of pfaffians. The first is tridiagonalization based on Householder transformations. The main advantage of this method is its numerical stability that makes unnecessary the implementation of a pivoting strategy. The second method considered is based on Aitken?s block diagonalization formula. It yields to a kind of LU (similar to Cholesky?s factorization) decomposition (under congruence) of arbitrary skew-symmetric matrices that is well suited both for the numeric and symbolic evaluations of the pfaffian. Fortran subroutines (FORTRAN 77 and 90) implementing both methods are given. We also provide simple implementations in Python and Mathematica for purpose of testing, or for exploratory studies of methods that make use of pfaffians.

Program summary

Program title:PfaffianCatalogue identifier: AEJD_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJD_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 2281No. of bytes in distributed program, including test data, etc.: 13 226Distribution format: tar.gzProgramming language: Fortran 77 and 90Computer: Any supporting a FORTRAN compilerOperating system: Any supporting a FORTRAN compilerRAM: a few MBClassification: 4.8Nature of problem: Evaluation of the pfaffian of a skew symmetric matrix. Evaluation of pfaffians arises in a number of physics applications involving fermionic mean field wave functions and their overlaps.Solution method: Householder tridiagonalization. Aitken?s block diagonalization formula.Additional comments: Python and Mathematica implementations are provided in the main body of the paper.Running time: Depends on the size of the matrices. For matrices with 100 rows and columns a few milliseconds are required.     

Controllability of Semilinear Systems of Parabolic Equations with Delay on the State

In this paper we prove the approximate controllability of the following semilinear system parabolic equations with delay on the state variable where Ω is a bounded domain in is a n × n non diagonal matrix whose eigenvalues are semi‐simple with non negative real part, the control u belongs to and B is a n × m matrix. Here τ≥0 is the maximum delay, which is supposed to be finite. We assume that the operator L:L²([?τ,0];Z)→Z is linear and bounded with and the nonlinear function f:[0,r] × IRⁿ×IR^m→IRⁿ is smooth and bounded.     

A superspace module for the FeynRules package

We describe an additional module for the Mathematica package FeynRules that allows for an easy building of any N=1 supersymmetric quantum field theory, directly in superspace. After the superfield content of a specific model has been implemented, the user can study the properties of the model, such as the supersymmetric transformation laws of the associated Lagrangian, directly in Mathematica. While the model dependent parts of the latter, i.e., the soft supersymmetry-breaking Lagrangian and the superpotential, have to be provided by the user, the model independent pieces, such as the gauge interaction terms, are derived automatically. Using the strengths of the FeynRules program, it is then possible to derive all the Feynman rules associated to the model and implement them in all the Feynman diagram calculators interfaced to FeynRules in a straightforward way.

Program summary

Program title: “FeynRules”Catalogue identifier: AEDI_v1_1Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDI_v1_1.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 46 491No. of bytes in distributed program, including test data, etc.: 381 582Distribution format: tar.gzProgramming language: MathematicaComputer: Platforms on which Mathematica is availableOperating system: Operating systems on which Mathematica is availableClassification: 11.1, 11.6Catalogue identifier of previous version: AEDI_v1_0Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 1614Does the new version supersede the previous version?: NoNature of problem: Study of the properties of N=1 supersymmetric field theories using the superfield formalism, derivation of the associated Lagrangians.Solution method: We use the FeynRules package and define internally the N=1 superspace. Then, we implement a module allowing to:

• 1. 

  Perform the Grassmann variable series expansion so that any superfield expression can be developed in terms of the component fields. The resulting expression is thus suitable to be treated by the FeynRules package directly.

• 2. 

  Execute a set of operations associated to the superspace, such as the superderivatives of an expression or the calculation of its supersymmetric transformation laws.

Reasons for new version: This is an interim update to the FeynRules-1.4 (AEDI_v1_0), package which includes a new superspace module. Further modules will be added in the future and eventually published as FeynRules-1.6.Summary of revisions: This revised version contains, in addition to the core program, the superfield module of FeynRules.Restrictions: Superfields related to spin 3/2 and 2 particles are not implemented.Unusual features: All calculations in the internal routines are performed completely. The only hardcoded core is the Grassmann variable algebra.Running time: It depends on the user?s purposes. The extraction of a Lagrangian in terms of the component fields may take a few minutes for a complete model with complex mixing between the fields.     

Evaluating FINESSE: a case-study in group-based CAL

The FINESSE project (Finance Education in a Scalable Software Environment)¹ addresses problems associated with the teaching of finance courses in the UK Higher Education sector by constructing a networked, computer-based portfolio management game. The FINESSE consortium consists of finance lecturers at the Universities of Dundee, Strathclyde, Glasgow, Aberdeen and Glasgow Caledonian University, and members of the Computer Sciences division at the University of St Andrews. Subject-specific resources were developed to exploit access to real-time stock-market data thereby allowing students to explore portfolio management strategies in a new and exciting way. This paper focuses on the need for a mix of methods when evaluating a CAL project, and on the desirability of including evaluation as part of the design stage and of the development process. We describe the various approaches employed to evaluate different aspects of FINESSE throughout the first 2 years of its use, and present the results of a student questionnaire.     

ALTDSE: An Arnoldi–Lanczos program to solve the time-dependent Schrödinger equation

We describe a general ab initio and non-perturbative method to solve the time-dependent Schrödinger equation (TDSE) for the interaction of a strong attosecond laser pulse with a general atom. While the field-free Hamiltonian and the dipole matrices may be generated using an arbitrary primitive basis, they are assumed to have been transformed to the eigenbasis of the problem before the solution of the TDSE is propagated in time using the Arnoldi–Lanczos method. Probabilities for survival of the ground state, excitation, and single ionization can be extracted from the propagated wavefunction.

Program summary

Program title: ALTDSECatalogue identifier: AEDM_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDM_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 2154No. of bytes in distributed program, including test data, etc.: 30 827Distribution format: tar.gzProgramming language: Fortran 95. [A Fortran 2003 call to “flush” is used to simplify monitoring the output file during execution. If this function is not available, these statements should be commented out.].Computer: Shared-memory machinesOperating system: Linux, OpenMPHas the code been vectorized or parallelized?: YesRAM: Several Gb, depending on matrix size and number of processorsSupplementary material: To facilitate the execution of the program, Hamiltonian field-free and dipole matrix files are provided.Classification: 2.5External routines: LAPACK, BLASNature of problem: We describe a computer program for a general ab initio and non-perturbative method to solve the time-dependent Schrödinger equation (TDSE) for the interaction of a strong attosecond laser pulse with a general atom [1,2]. The probabilities for survival of the initial state, excitation of discrete states, and single ionization due to multi-photon processes can be obtained.Solution method: The solution of the TDSE is propagated in time using the Arnoldi–Lanczos method. The field-free Hamiltonian and the dipole matrices, originally generated in an arbitrary basis (e.g., the flexible B-spline R-matrix (BSR) method with non-orthogonal orbitals [3]), must be provided in the eigenbasis of the problem as input.Restrictions: The present program is restricted to a ¹S^e initial state and linearly polarized light. This is the most common situation experimentally, but a generalization is straightforward.Running time: Several hours, depending on the number of threads used.References: [1] X. Guan, O. Zatsarinny, K. Bartschat, B.I. Schneider, J. Feist, C.J. Noble, Phys. Rev. A 76 (2007) 053411. [2] X. Guan, C.J. Noble, O. Zatsarinny, K. Bartschat, B.I. Schneider, Phys. Rev. A 78 (2008) 053402. [3] O. Zatsarinny, Comput. Phys. Comm. 174 (2006) 273.     

SLHAplus: A library for implementing extensions of the standard model

We provide a library to facilitate the implementation of new models in codes such as matrix element and event generators or codes for computing dark matter observables. The library contains an SLHA reader routine as well as diagonalisation routines. This library is available in CalcHEP and micrOMEGAs. The implementation of models based on this library is supported by LanHEP and FeynRules.

Program summary

Program title: SLHAplus_1.3Catalogue identifier: AEHX_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHX_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 6283No. of bytes in distributed program, including test data, etc.: 52 119Distribution format: tar.gzProgramming language: CComputer: IBM PC, MACOperating system: UNIX (Linux, Darwin, Cygwin)RAM: 2000 MBClassification: 11.1Nature of problem: Implementation of extensions of the standard model in matrix element and event generators and codes for dark matter observables.Solution method: For generic extensions of the standard model we provide routines for reading files that adopt the standard format of the SUSY Les Houches Accord (SLHA) file. The procedure has been generalized to take into account an arbitrary number of blocks so that the reader can be used in generic models including non-supersymmetric ones. The library also contains routines to diagonalize real and complex mass matrices with either unitary or bi-unitary transformations as well as routines for evaluating the running strong coupling constant, running quark masses and effective quark masses.Running time: 0.001 sec     

Linguistic hedges and the generalized modus ponens

In this paper a modification of the generalized modus ponens is presented, namely, rule: if X is bB then Y is cC; fact: X is aB, conclusion: Y is dC where a, b, c, e, and d are linguistic hedges, and B, C are fuzzy sets. The procedure that allows one to evaluate the modifier d is very simple and gives results given in Refs. 15, 18, 26, and 27. Our approach is algebraic-based and realizes Zadeh's calculus on words by means of Chang's MV algebra. ©1999 John Wiley & Sons, Inc.     

PHON: A program to calculate phonons using the small displacement method

The program phon calculates force constant matrices and phonon frequencies in crystals. From the frequencies it also calculates various thermodynamic quantities, like the Helmholtz free energy, the entropy, the specific heat and the internal energy of the harmonic crystal. The procedure is based on the small displacement method, and can be used in combination with any program capable to calculate forces on the atoms of the crystal. In order to examine the usability of the method, I present here two examples: metallic Al and insulating MgO. The phonons of these two materials are calculated using density functional theory. The small displacement method results are compared with those obtained using the linear response method. In the case of Al the method provides accurate phonon frequencies everywhere in the Brillouin Zone (BZ). In the case of MgO the longitudinal branch of the optical phonons near the centre of the BZ is incorrectly described as degenerate with the two transverse branches, because the non-analytical part of the dynamical matrix is ignored here; however, thermodynamic properties like the Helmholtz free are essentially unaffected.

Program summary

Program title: PHONCatalogue identifier: AEDP_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDP_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 19 580No. of bytes in distributed program, including test data, etc.: 612 193Distribution format: tar.gzProgramming language: Fortran 90Computer: Any Unix, LinuxOperating system: UnixRAM: Depends on super-cell size, but usually negligibleClassification: 7.8External routines: Subprograms ZHEEV and DSYEV (Lapack); needs BLAS. A tutorial is provided with the distribution which requires the installation of the quantum-espresso package (http://www.quantum-espresso.org)Nature of problem: Stable crystals at low temperature can be well described by expanding the potential energy around the atomic equilibrium positions. The movements of the atoms around their equilibrium positions can then be described using harmonic theory, and is characterised by global vibrations called phonons, which can be identified by vectors in the Brillouin zone of the crystal, and there are 3 phonon branches for each atom in the primitive cell. The problem is to calculate the frequencies of these phonons for any arbitrary choice of q-vector in the Brillouin zone.Solution method: The small displacement method: each atom in the primitive cell is displaced by a small amount, and the forces induced on all the other atoms in the crystal are calculated and used to construct the force constant matrix. Supercells of ∼100 atoms are usually large enough to describe the force constant matrix up to the range where its elements have fallen to negligibly small values. The force constant matrix is then used to compute the dynamical matrix at any chosen q-vector in the Brillouin zone, and the diagonalisation of the dynamical matrix provides the squares of the phonon frequencies. The PHON code needs external programs to calculate these forces, and it can be used with any program capable of calculating forces in crystals. The most useful applications are obtained with codes based on density functional theory, but there is no restriction on what can be used.Running time: Negligible, typically a few seconds (or at most a few minutes) on a PC. It can take longer if very dense meshes of q-points are needed, for example, to compute very accurate phonon density of states.     

James Clerk Maxwell's Glasgow manuscripts: extracts relating to control and stability

Four of Maxwell's letters which were written to William Thomson, and are currently held by Glasgow University Library, are reproduced and discussed. Some of the material relates to control, and leads to possible explanations of certain points which were treated enigmatically in Maxwell's 1868 paper on governors.     

OneLOop: For the evaluation of one-loop scalar functions

OneLOop is a program to evaluate the one-loop scalar 1-point, 2-point, 3-point and 4-point functions, for all kinematical configurations relevant for collider-physics, and for any non-positive imaginary parts of the internal squared masses. It deals with all UV and IR divergences within dimensional regularization. Furthermore, it provides routines to evaluate these functions using straightforward numerical integration.

Program summary

Program title: OneLOopCatalogue identifier: AEJO_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJO_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 12 061No. of bytes in distributed program, including test data, etc.: 74 163Distribution format: tar.gzProgramming language: FortranComputer: WorkstationsOperating system: Linux, UnixRAM: NegligibleClassification: 4.4, 11.1Nature of problem: In order to reach next-to-leading order precision in the calculation of cross sections of hard scattering processes, one-loop amplitudes have to be evaluated. This is done by expressing them as linear combination of one-loop scalar functions. In a concrete calculation, these functions eventually have to be evaluated. If the scattering process involves unstable particles, consistency requires the evaluation of these functions with complex internal masses.Solution method: Expressions for the one-loop scalar functions in terms of single-variable analytic functions existing in literature have been implemented.Restrictions: The applicability is restricted to the kinematics occurring in collider-physics.Running time: The evaluation of the most general 4-point function with 4 complex masses takes about 180 μs, and the evaluation of the 4-point function with 4 real masses takes about 18 μs on a 2.80 GHz Intel Xeon processor.     

A uniform object-oriented solution to the eigenvalue problem for real symmetric and Hermitian matrices

We present a system of classes, SHMatrix, to deal in a unified way with the computation of eigenvalues and eigenvectors in real symmetric and Hermitian matrices. Thus, two descendant classes, one for the real symmetric and other for the Hermitian cases, override the abstract methods defined in a base class. The use of the inheritance relationship and polymorphism allows handling objects of any descendant class using a single reference of the base class. The system of classes is intended to be the core element of more sophisticated methods to deal with large eigenvalue problems, as those arising in the variational treatment of realistic quantum mechanical problems. The present system of classes allows computing a subset of all the possible eigenvalues and, optionally, the corresponding eigenvectors. Comparison with well established solutions for analogous eigenvalue problems, as those included in LAPACK, shows that the present solution is competitive against them.

Program summary

Program title: SHMatrixCatalogue identifier: AEHZ_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHZ_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 2616No. of bytes in distributed program, including test data, etc.: 127 312Distribution format: tar.gzProgramming language: Standard ANSI C++.Computer: PCs and workstations.Operating system: Linux, Windows.Classification: 4.8.Nature of problem: The treatment of problems involving eigensystems is a central topic in the quantum mechanical field. Here, the use of the variational approach leads to the computation of eigenvalues and eigenvectors of real symmetric and Hermitian Hamiltonian matrices. Realistic models with several degrees of freedom leads to large (sometimes very large) matrices. Different techniques, such as divide and conquer, can be used to factorize the matrices in order to apply a parallel computing approach. However, it is still interesting to have a core procedure able to tackle the computation of eigenvalues and eigenvectors once the matrix has been factorized to pieces of enough small size. Several available software packages, such as LAPACK, tackled this problem under the traditional imperative programming paradigm. In order to ease the modelling of complex quantum mechanical models it could be interesting to apply an object-oriented approach to the treatment of the eigenproblem. This approach offers the advantage of a single, uniform treatment for the real symmetric and Hermitian cases.Solution method: To reach the above goals, we have developed a system of classes: SHMatrix. SHMatrix is composed by an abstract base class and two descendant classes, one for real symmetric matrices and the other for the Hermitian case. The object-oriented characteristics of inheritance and polymorphism allows handling both cases using a single reference of the base class. The basic computing strategy applied in SHMatrix allows computing subsets of eigenvalues and (optionally) eigenvectors. The tests performed show that SHMatrix is competitive, and more efficient for large matrices, than the equivalent routines of the LAPACK package.Running time: The examples included in the distribution take only a couple of seconds to run.