E-Macsc: A Novel Dynamic Cache Tuning Technique to Maintain the hit ratio prescribes by the user in internet applications

Department of ComputingRefereed conference pape

Revisiting the relativistic ejection event in XTE J1550-564 during the 1998 outburst

We revisit the discovery outburst of the X-ray transient XTE J1550−564 during which relativistic jets were observed in 1998 September, and review the radio images obtained with the Australian Long Baseline Array, and light curves obtained with the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array. Based on Hi spectra, we constrain the source distance to between 3.3 and 4.9 kpc. The radio images, taken some 2 d apart, show the evolution of an ejection event. The apparent separation velocity of the two outermost ejecta is at least 1.3c and may be as large as 1.9c; when relativistic effects are taken into account, the inferred true velocity is ≥ 0.8c. The flux densities appear to peak simultaneously during the outburst, with a rather flat (although still optically thin) spectral index of −0.2

A comprehensive study of the open cluster NGC 6866

We present CCD $UBVRI$ photometry of the field of the open cluster NGC 6866. Structural parameters of the cluster are determined utilizing the stellar density profile of the stars in the field. We calculate the probabilities of the stars being a physical member of the cluster using their astrometric data and perform further analyses using only the most probable members. The reddening and metallicity of the cluster were determined by independent methods. The LAMOST spectra and the ultraviolet excess of the F and G type main-sequence stars in the cluster indicate that the metallicity of the cluster is about the solar value. We estimated the reddening $E(B-V)=0.074 \pm 0.050$ mag using the $U-B$ vs $B-V$ two-colour diagram. The distance modula, the distance and the age of NGC 6866 were derived as $\mu = 10.60 \pm 0.10$ mag, $d=1189 \pm 75$ pc and $t = 813 \pm 50$ Myr, respectively, by fitting colour-magnitude diagrams of the cluster with the PARSEC isochrones. The Galactic orbit of NGC 6866 indicates that the cluster is orbiting in a slightly eccentric orbit with $e=0.12$. The mass function slope $x=1.35 \pm 0.08$ was derived by using the most probable members of the cluster.Comment: 14 pages, including 16 figures and 7 tables, accepted for publication in MNRAS. Table 4 in the manuscript will be published electronicall

Solving kk-means on High-dimensional Big Data

In recent years, there have been major efforts to develop data stream algorithms that process inputs in one pass over the data with little memory requirement. For the $k$-means problem, this has led to the development of several $(1+\varepsilon)$-approximations (under the assumption that $k$ is a constant), but also to the design of algorithms that are extremely fast in practice and compute solutions of high accuracy. However, when not only the length of the stream is high but also the dimensionality of the input points, then current methods reach their limits. We propose two algorithms, piecy and piecy-mr that are based on the recently developed data stream algorithm BICO that can process high dimensional data in one pass and output a solution of high quality. While piecy is suited for high dimensional data with a medium number of points, piecy-mr is meant for high dimensional data that comes in a very long stream. We provide an extensive experimental study to evaluate piecy and piecy-mr that shows the strength of the new algorithms.Comment: 23 pages, 9 figures, published at the 14th International Symposium on Experimental Algorithms - SEA 201

Synthesis, crystal structure, magnetic and electronic properties of the caesium-based transition metal halide Cs<inf>3</inf>Fe<inf>2</inf>Br<inf>9</inf>

The diversity of halide materials related to important solar energy systems such as CsPbX3 (X = Cl, Br, I) is explored by introducing the transition metal element Fe. In particular a new compound, Cs3Fe2Br9 (space group P6_3/mmc with a = 7.5427(8) and c = 18.5849(13) {\AA}), has been synthesized and found to contain 0D face-sharing Fe2Br9 octahedral dimers. Unlike its isomorph, Cs3Bi2I9, it is black in color, has a low optical bandgap of 1.65 eV and exhibits antiferromagnetic behavior below TN = 13 K. Density functional theory calculations shed further light on these properties and also predict that the material should have anisotropic transport characteristics

Quantitative brain-derived neurotrophic factor lateral flow assay for point-of-care detection of glaucoma

Glaucoma, a ruinous group of eye diseases with progressive degeneration of the optic nerve and vision loss, is the leading cause of irreversible blindness. Accurate and timely diagnosis of glaucoma is critical to promote secondary prevention and early disease-modifying therapies. Reliable, cheap, and rapid tests for measuring disease activities are highly required. Brain-derived neurotrophic factor (BDNF) plays an important role in maintaining the function and survival of the central nervous system. Decreased BDNF levels in tear fluid can be seen in glaucoma patients, which indicates that BDNF can be regarded as a novel biomarker for glaucoma. Conventional ELISA is the standard method to measure the BDNF level, but the multi-step operation and strict storage conditions limit its usage in point-of-care settings. Herein, a one-step and a portable glaucoma detection method was developed based on the lateral flow assay (LFA) to quantify the BDNF concentration in artificial tear fluids. The results of the LFA were analyzed by using a portable and low-cost system consisting of a smartphone camera and a dark readout box fabricated by 3D printing. The concentration of BDNF was quantified by analyzing the colorimetric intensity of the test line and the control line. This assay yields reliable quantitative results from 25 to 300 pg mL-1 with an experimental detection limit of 14.12 pg mL-1. The LFA shows a high selectivity for BDNF and high stability in different pH environments. It can be readily adapted for sensitive and quantitative testing of BDNF in a point-of-care setting. The BDNF LFA strip shows it has great potential to be used in early glaucoma detection

Giant half-cycle attosecond pulses

Half-cycle picosecond pulses have been produced from thin photo-conductors, when applying an electric field across the surface and switching on conduction by a short laser pulse. Then the transverse current in the wafer plane emits half-cycle pulses in normal direction, and pulses of 500 fs duration and 1e6 V/m peak electric field have been observed. Here we show that single half-cycle pulses of 50 as duration and up to 1e13 V/m can be produced when irradiating a double foil target by intense few-cycle laser pulses. Focused onto an ultra-thin foil, all electrons are blown out, forming a uniform sheet of relativistic electrons. A second layer, placed at some distance behind, reflects the drive beam, but lets electrons pass straight. Under oblique incidence, beam reflection provides the transverse current, which emits intense half-cycle pulses. Such a pulse may completely ionize even heavier atoms. New types of attosecond pump-probe experiments will become possible.Comment: 5 pages, 4 figures, to be presented at LEI2011-Light at Extreme Intensities and China-Germany Symposium on Laser Acceleratio

ATOM: AI-Powered Sustainable Resource Management for Serverless Edge Computing Environments

Serverless edge computing decreases unnecessary resource usage on end devices with limited processing power and storage capacity. Despite its benefits, serverless edge computing&#x0027;s zero scalability is the major source of the cold start delay, which is yet unsolved. This latency is unacceptable for time-sensitive Internet of Things (IoT) applications like autonomous cars. Most existing approaches need containers to idle and use extra computing resources. Edge devices have fewer resources than cloud-based systems, requiring new sustainable solutions. Therefore, we propose an AI-powered, sustainable resource management framework called ATOM for serverless edge computing. ATOM utilizes a deep reinforcement learning model to predict exactly when cold start latency will happen. We create a cold start dataset using a heart disease risk scenario and deploy using Google Cloud Functions. To demonstrate the superiority of ATOM, its performance is compared with two different baselines, which use the warm-start containers and a two-layer adaptive approach. The experimental results showed that although the ATOM required more calculation time of 118.76 seconds, it performed better in predicting cold start than baseline models with an RMSE ratio of 148.76. Additionally, the energy consumption and $CO_{2}$ emission amount of these models are evaluated and compared for the training and prediction phases

Molecular Identification of Spirometra erinaceieuropaei Tapeworm in Cases of Human Sparganosis, Hong Kong

Human sparganosis is a foodborne zoonosis endemic in Asia. We report a series of 9 histologically confirmed human sparganosis cases in Hong Kong, China. All parasites were retrospectively identified as Spirometra erinaceieuropaei. Skin and soft tissue swelling was the most common symptom, followed by central nervous system lesions.published_or_final_versio