A semantic basis for parallel algorithm design

As computing demands increase, emphasis is being placed on parallel architectures- To efficiently use parallel machines, software must be designed to take advantage of these machines. This research concentrates on an abstraction of algorithm design to permit the expression of parallel programs. The abstraction emphasizes thought about algorithms at a high level as opposed to algorithm implementation at a statement level. A model based on data flow allows algorithm expression using flow diagrams. The model specifies operating system requirements that support parallel programming at a module level. Paths are used to carry data between modules. Data enter modules through ports. Module activation is triggered by the satisfaction of data availability conditions. Continual module presence within the system, dynamic activation criteria, and a high level of programming distinguishes this model from other parallel programming systems --Abstract, page ii

BD+36 3317: An algol type eclipsing binary in Delta Lyrae cluster

In this paper, we present standard Johnson UBV photometry of the eclipsing binary BD+36 3317 which is known as a member of Delta Lyrae (Stephenson 1) cluster. We determined colors and brightness of the system, calculated E(B - V) color excess. We discovered that the system shows total eclipse in secondary minimum. Using this advantage, we found that the primary component of the system has B9 - A0 spectral type. Although there is no published orbital solution, we tried to estimate the physical properties of the system from simultaneous analysis of UBV light curves with 2003 version of Wilson-Devinney code. Then we considered photometric solution results together with evolutionary models and estimated the masses of the components as M1 = 2.5 Msun and M2 = 1.6 Msun. Those estimations gave the distance of the system as 353 pc. Considering the uncertainties in distance estimation, resulting distance is in agreement with the distance of Delta Lyrae cluster.Comment: 18 pages, 4 figures, 5 table

Screening of heterogeneous surfaces: charge renormalization of Janus particles

Nonlinear ionic screening theory for heterogeneously charged spheres is developed in terms of a mode-decomposition of the surface charge. A far-field analysis of the resulting electrostatic potential leads to a natural generalization of charge renormalization from purely monopolar to dipolar, quadropolar, etc., including mode-couplings. Our novel scheme is generally applicable to large classes of surface heterogeneities, and is explicitly applied here to Janus spheres with differently charged upper and lower hemispheres, revealing strong renormalization effects for all multipoles.Comment: 2 figure

The cue is key: Design for real-life remembering

This paper aims to put the memory cue in the spotlight. We show how memory cues are incorporated in the area of interaction design. The focus is on external memory cues - cues that exist outside the human mind but have an internal effect on memory reconstruction. Examples of external cues include people, environments, and things, where the latter are most relevant for the aim of this paper since these cues can be incorporated in designs. This paper makes a dual contribution to research: (1) it provides insights into how memory research informs the design of devices to facilitate personal memory recall; and (2) by taking a design perspective, it raises questions about memory cues as part of real-life remembering to inform psychological memory research. Since memory theory inspires design and both fields would benefit from collaboration, we would like these questions to be an inspiration for future memory research, in particular targeting external memory cues. © 2014 Hogrefe Publishing

A Semantic Basis for Parallel Algorithm Design

As computing demands increase, emphasis is being placed on parallel architectures- To efficiently use parallel machines, software must be designed to take advantage of these machines. This research concentrates on an abstraction of algorithm design to permit the expression of parallel programs. The abstraction emphasizes thought about algorithms at a high level as opposed to algorithm implementation at a statement level. A model based on data flow allows algorithm expression using flow diagrams. The model specifies operating system requirements that support parallel programming at a module level. Paths are used to carry data between modules. Data enter modules through ports. Module activation is triggered by the satisfaction of data availability conditions. Continual module presence within the system, dynamic activation criteria, and a high level of programming distinguishes this model from other parallel programming systems

Optical polarisation variability of radio loud narrow line Seyfert 1 galaxies. Search for long rotations of the polarisation plane

Narrow line Seyfert 1 galaxies (NLSy1s) constitute the AGN subclass associated with systematically smaller black hole masses. A few radio loud ones have been detected in MeV -- GeV energy bands by Fermi and evidence for the presence of blazar-like jets has been accumulated. In this study we wish to quantify the temporal behaviour of the optical polarisation, fraction and angle, for a selected sample of radio loud NLSy1s. We also search for rotations of the polarisation plane similar to those commonly observed in blazars. We have conducted R-band optical polarisation monitoring of a sample of 10 RL NLSy1s 5 of which have been previously detected by Fermi. The dataset includes observations with the RoboPol, KANATA, Perkins and Steward polarimeters. In the cases where evidences for long rotations of the polarisation plane are found, we carry out numerical simulations to assess the probability that they are caused by intrinsically evolving EVPAs instead of observational noise. Even our moderately sampled sources show indications of variability, both in polarisation fraction and angle. For the four best sampled objects in our sample we find multiple periods of significant polarisation angle variability. In the two best sampled cases, namely J1505+0326 and J0324+3410, we find indications for three long rotations. We show that although noise can induce the observed behaviour, it is much more likely that the apparent rotation is caused by intrinsic evolution of the EVPA. To our knowledge this is the very first detection of such events in this class of sources. In the case of the largest dataset (J0324+3410) we find that the EVPA concentrates around a direction which is at 49.3\degr to the 15-GHz radio jet implying a projected magnetic field at an angle of 40.7\degr to that axis.Comment: Accepted for publication in section 2. Astrophysical processes of Astronomy and Astrophysic

Morris Water Maze Learning in Two Rat Strains Increases the Expression of the Polysialylated Form of the Neural Cell Adhesion Molecule in the Dentate Gyrus But Has No Effect on Hippocampal Neurogenesis

In the current study, the authors investigated whether Morris water maze learning induces alterations in hippocampal neurogenesis or neural cell adhesion molecule (NCAM) polysialylation in the dentate gyrus. Two frequently used rat strains, Wistar and Sprague–Dawley, were trained in the spatial or the nonspatial version of the water maze. Both training paradigms did not have an effect on survival of newly formed cells that were labeled 7–9 days prior to the training or on progenitor proliferation in the subgranular zone. However, the granule cell layer of the spatially trained rats contained significantly more positive cells of the polysialylated form of the NCAM. These data demonstrate that Morris water maze learning causes plastic change in the dentate gyrus without affecting hippocampal neurogenesis.

Search for low instability strip variables in the young open cluster NGC 2516

In this paper we revise and complete the photometric survey of the instability strip of the southern open cluster NGC 2516 published by Antonello and Mantegazza (1986). No variable stars with amplitudes larger than $0^m.02$ were found. However by means of an accurate analysis based on a new statistical method two groups of small amplitude variables have been disentangled: one with periods $< 0^d.25$ (probably $\delta$ Scuti stars) and one with periods $>0^d.025$. The position in the HR diagram and the apparent time-scale may suggest that the stars of the second group belong to a recently discovered new class of variables, named $\gamma$ Dor variables. They certainly deserve further study. We also present a comparison between the results of the photometric survey and the available pointed ROSAT observations of this cluster.Comment: 7 pages, 2 ps figures. Accepted for P.A.S.

Informing design for reflection: An overview of current everyday practices

© 2016 ACM. There is an increasing interest in HCI in designing to support reflection in users. In this paper, we specifically focus on everyday life reflection, covering and connecting a broad range of topics from someone's life rather than focusing on a very specific aspect. Although many systems aim to support reflection, few are based on an overview of how people currently integrate reflection in everyday life. In this paper, we aim to contribute to this gap through a questionnaire on everyday life reflection practices combining both qualitative and quantitative questions. Findings provide insights in the broad range of people that engage with reflection in different ways. We aim to inform design through four considerations: rumination, timing, initiative and social context

Peripheral interaction: characteristics and considerations

© 2014, Springer-Verlag London. In everyday life, we are able to perceive information and perform physical actions in the background or periphery of attention. Inspired by this observation, several researchers have studied interactive systems that display digital information in the periphery of attention. To broaden the scope of this research direction, a few recent studies have focused on interactive systems that can not only be perceived in the background but also enable users to physically interact with digital information in their periphery. Such peripheral interaction designs can support computing technology to fluently embed in and become a meaningful part of people’s everyday routines. With the increasing ubiquity of technology in our everyday environment, we believe that this direction is highly relevant nowadays. This paper presents an in-depth analysis of three case studies on peripheral interaction. These case studies involved the design and development of peripheral interactive systems and deployment of these systems in the real context of use for a number of weeks. Based on the insights gained through these case studies, we discuss generalized characteristics and considerations for peripheral interaction design and evaluation. The aim of the work presented in this paper is to support interaction design researchers and practitioners in anticipating and facilitating peripheral interaction with the designs they are evaluating or developing