A methodology for the design and evaluation of user interfaces for interactive information systems

The definition of proposed research addressing the development and validation of a methodology for the design and evaluation of user interfaces for interactive information systems is given. The major objectives of this research are: the development of a comprehensive, objective, and generalizable methodology for the design and evaluation of user interfaces for information systems; the development of equations and/or analytical models to characterize user behavior and the performance of a designed interface; the design of a prototype system for the development and administration of user interfaces; and the design and use of controlled experiments to support the research and test/validate the proposed methodology. The proposed design methodology views the user interface as a virtual machine composed of three layers: an interactive layer, a dialogue manager layer, and an application interface layer. A command language model of user system interactions is presented because of its inherent simplicity and structured approach based on interaction events. All interaction events have a common structure based on common generic elements necessary for a successful dialogue. It is shown that, using this model, various types of interfaces could be designed and implemented to accommodate various categories of users. The implementation methodology is discussed in terms of how to store and organize the information

Online Tensor Methods for Learning Latent Variable Models

We introduce an online tensor decomposition based approach for two latent variable modeling problems namely, (1) community detection, in which we learn the latent communities that the social actors in social networks belong to, and (2) topic modeling, in which we infer hidden topics of text articles. We consider decomposition of moment tensors using stochastic gradient descent. We conduct optimization of multilinear operations in SGD and avoid directly forming the tensors, to save computational and storage costs. We present optimized algorithm in two platforms. Our GPU-based implementation exploits the parallelism of SIMD architectures to allow for maximum speed-up by a careful optimization of storage and data transfer, whereas our CPU-based implementation uses efficient sparse matrix computations and is suitable for large sparse datasets. For the community detection problem, we demonstrate accuracy and computational efficiency on Facebook, Yelp and DBLP datasets, and for the topic modeling problem, we also demonstrate good performance on the New York Times dataset. We compare our results to the state-of-the-art algorithms such as the variational method, and report a gain of accuracy and a gain of several orders of magnitude in the execution time.Comment: JMLR 201

Nonlinear reversal of PT symmetric phase transition in a system of coupled semiconductor micro-ring resonators

A system of two coupled semiconductor-based resonators is studied when lasing around an exceptional point. We show that the presence of nonlinear saturation effects can have important ramifications on the transition behavior of this system. In sharp contrast with linear PT-symmetric configurations, nonlinear processes are capable of reversing the order in which the symmetry breaking occurs. Yet, even in the nonlinear regime, the resulting non-Hermitian states still retain the structural form of the corresponding linear eigenvectors expected above and below the phase transition point. The conclusions of our analysis are in agreement with experimental data.Comment: 9 pages, 8 figure

Microparticle image processing and field profile optimisation for automated Lab-On-Chip magnetophoretic analytical systems

The work described in this thesis, concerns developments to analytical microfluidic Lab-On-Chip platform originally developed by Prof Pamme's research group at the University of Hull. This work aims to move away from traditional laboratory analysis system towards a more effective system design which is fully automated and therefore potentially deployable in applications such as point of care medical diagnosis. The microfluidic chip platform comprises an external permanent magnet and chip with multiple parallel reagent streams through which magnetic micro-particles pass in sequence. These streams may include particles, analyte, fluorescent labels and wash solutions; together they facilitate an on-chip multi-step analytical procedure. Analyte concentration is measured via florescent intensity of the exiting micro-particles. This has previously been experimentally proven for more than one analytical procedure. The work described here has addressed a couple of issues which needed improvement, specifically optimizing the magnetic field and automating the measurement process. These topics are related by the fact that an optimal field will reduce anomalies such as aggregated particles which may degrade automated measurements.For this system, the optimal magnetic field is homogeneous gradient of sufficient strength to pull the particles across the width of the device during fluid transit of its length. To optimise the magnetic field, COMSOL (a Multiphysics simulation program) was used to evaluate a number of multiple magnet configurations and demonstrate an improved field profile. The simulation approach was validated against experimental data for the original single-magnet design.To analyse the results automatically, a software tool has been developed using C++ which takes image files generated during an experiment and outputs a calibration curve or specific measurement result. The process involves detection of the particles (using image segmentation) and object tracking. The intensity measurement follows the same procedure as the original manual approach, facilitating comparison, but also includes analysis of particle motion behaviour to allow automatic rejection of data from anomalous particles (e.g. stuck particles). For image segmentation a novel texture based technique called Temporal- Adaptive Median Binary Pattern (T-AMBP) combining with Three Frame Difference method to model the background for representing the foreground was proposed. This proposed approached is based on previously developed Adaptive Median Binary Pattern (AMBP) and Gaussian Mixture Model (GMM) approach for image segmentation. The proposed method successfully detects micro-particles even when they have very low fluorescent intensity, while most of the previous approaches failed and is more robust to noise and artefacts. For tracking the micro-particles, we proposed a novel algorithm called "Hybrid Meanshift", which combines Meanshift, Histogram of oriented gradients (HOG) matching and optical flow techniques. Kalman filter was also combined with it to make the tracking robust.The processing of an experimental data set for generating a calibration curve, getting effectively the same results in less than 5 minutes was demonstrated, without needing experimental experience, compared with at least 2 hours work by an experienced experimenter using the manual approach

Integrable nonlinear parity-time symmetric optical oscillator

The nonlinear dynamics of a balanced parity-time symmetric optical microring arrangement are analytically investigated. By considering gain and loss saturation effects, the pertinent conservation laws are explicitly obtained in the Stokes domain-thus establishing integrability. Our analysis indicates the existence of two regimes of oscillatory dynamics and frequency locking, both of which are analogous to those expected in linear parity-time symmetric systems. Unlike other saturable parity time symmetric systems considered before, the model studied in this work first operates in the symmetric regime and then enters the broken parity-time phase.Comment: 6 pages, 5 figures, accepted for publicatio

Chemical and biological investigations of Delonix regia (Bojer ex Hook.) Raf.

U radu je opisana izolacija pet sastojaka petroleterske i diklormetanske frakcije metanolnog ekstrakta kore biljke Delonix regia: lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) i p-metoksibenzaldehid (5). Nadalje, testirano je antimikrobno djelovanje različitih ekstrakata difuzijskom metodom na disku (15 μg mm2). Zone inhibicije za sastojke topljive u petroleteru, tetraklormetanu i diklormetanu bile su 914 mm, 1113 mm, odnosno 920 mm, dok je zona inhibicije standarda kanamicina bila 2025 mm. U biološkom pokusu smrtnosti morskih kozica najveću toksičnost pokazali su spojevi topljivi u tetraklormetanu (LC50 = 0,83 μg mL1), dok je topljivost sastojaka topljivih u petroleteru i diklormetanu bila LC50 14,94, odnosno 3,29 μg mL1, a standarda vinkristin sulfata 0,812 μg mL1. Ovo je prvo izvješće o izolaciji sastojaka, antimikrobnom djelovanju i citotoksičnosti biljke D. regia.In this study five compounds, lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) and p-methoxybenzaldehyde (5) were isolated from the petroleum ether and dichloromethane fractions of a methanolic extract of the stem bark of Delonix regia. Antimicrobial screening of the different extracts (15 μg mm2) was conducted by disc diffusion method. The zones of inhibition demonstrated by the petroleum ether, carbon tetrachloride and dichloromethane fractions ranged from 914 mm, 1113 mm and 920 mm, respectively, compared to kanamycin standard with the zone of inhibition of 2025 mm. In brine shrimp lethality bioassay, the carbon tetrachloride soluble materials demonstrated the highest toxicity with LC50 of 0.83 μg mL1, while petroleum ether and dichloromethane soluble partitionates of the methanolic extract revealed LC50 of 14.94 and 3.29 μg mL1, respectively, in comparison with standard vincristine sulphate with LC50 of 0.812 μg mL1. This is the first report on compounds separation from D. regia, their antimicrobial activity and cytotoxicity

HEER: Hybrid Energy Efficient Reactive Protocol for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) consist of numerous sensors which send sensed data to base station. Energy conservation is an important issue for sensor nodes as they have limited power.Many routing protocols have been proposed earlier for energy efficiency of both homogeneous and heterogeneous environments. We can prolong our stability and network lifetime by reducing our energy consumption. In this research paper, we propose a protocol designed for the characteristics of a reactive homogeneous WSNs, HEER (Hybrid Energy Efficient Reactive) protocol. In HEER, Cluster Head(CH) selection is based on the ratio of residual energy of node and average energy of network. Moreover, to conserve more energy, we introduce Hard Threshold (HT) and Soft Threshold (ST). Finally, simulations show that our protocol has not only prolonged the network lifetime but also significantly increased stability period.Comment: 2nd IEEE Saudi International Electronics, Communications and Photonics Conference (SIECPC 13), 2013, Riyadh, Saudi Arabi

Study of Soret and Ion slip effects on MHD flow near an Oscillating Vertical Plate in a Rotating System

This study analyses the Soret, Hall and ion slip effects on a free convective flow of an electrically conducting, incompressible and viscous fluid near the vertical oscillatory infinite plate in a rotating system. A set of dimensionless governing equations of the model is obtained. As the equations are linear, an exact solution can be obtained by using Laplace transform method. The influence of various parameters on the concentration, temperature, velocity, Sherwood number and Nusselt number are discussed with the help of graphs. The numerical values of skin-friction are shown in tables. Applications of the study arise in field like planetary and solar plasma fluid dynamical systems, magnetic field controlled materials processing systems, rotating MHD induction machine energy generators etc

Development of a retractable tray dryer for drying crops in solar PV farms

Temperature plays a significant element in Solar PV technology as well as herbal growth. Significant research laboratories have proven that approximately 0.5% electricity from PV generators are reduced based on 1°C increase of the module temperature which is dispersed as heat energy whereas increasing temperature may degrade the plant growth. Harvesting the dissipated heat from the bottom surface of a Photovoltaic (PV) Array is currently a new research area which is in line with sustainable urban development. This study suggested a new prototype of Retractable Tray Dryer (RtD) be embedded directly under PV arrays as means of harvesting the dissipated heat as well as reducing the bottom temperature within the concept of heat convection. The tray dryer is designed in such a way that it can be suited to any PV structures and can be clustered for a large scale farm. A specified leavy-type herbal crop was used as sample and tested at the Universiti Putra Malaysia PV Pilot site. Field test of the embedded tray as compared to the normal system showed higher drying rate for RtD which produces higher yield and good quality of dried crops