arXiv subjects

Shakeel Ahmad

Publications and source records attributed to Shakeel Ahmad.

At least 55 records · Page 3Linked to original sources

arXiv2020

TAO Conceptual Design Report: A Precision Measurement of the Reactor Antineutrino Spectrum with Sub-percent Energy Resolution

The Taishan Antineutrino Observatory (TAO, also known as JUNO-TAO) is a satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). A ton-level liquid scintillator detector will be placed at about 30 m from a core of the Taishan Nuclear Power Plant. The reactor antineutrino spectrum will be measured with sub-percent energy resolution, to provide a reference spectrum for future reactor neutrino experiments, and to provide a benchmark measurement to test nuclear databases. A spherical acrylic vessel containing 2.8 ton gadolinium-doped liquid scintillator will be viewed by 10 m^2 Silicon Photomultipliers (SiPMs) of >50% photon detection efficiency with almost full coverage. The photoelectron yield is about 4500 per MeV, an order higher than any existing large-scale liquid scintillator detectors. The detector operates at -50 degree C to lower the dark noise of SiPMs to an acceptable level. The detector will measure about 2000 reactor antineutrinos per day, and is designed to be well shielded from cosmogenic backgrounds and ambient radioactivities to have about 10% background-to-signal ratio. The experiment is expected to start operation in 2022.

physics.ins-det↗

arXiv2019

Centrality Dependence of Multiplicity Fluctuations in Ion-Ion Collisions from the Beam Energy Scan at FAIR

Multiplicity distributions and event-by-event multiplicity fluctuations in AuAu collisions at energies in future heavy-ion experiment at the Facility for Anti-proton and Ion Research (FAIR) are investigated. Events corresponding to FAIR energies are simulated in the frame work of Ultra Relativistic Quantum Molecular Dynamics (URQMD) model. It is observed that the mean and the width of multiplicity distributions monotonically increase with beam energy. The trend of variations of dispersion with mean number of participating nucleons for the centrality-bin width of 5\% are in accord with the Central Limit Theorem. The multiplicity distributions in various centrality bins as well as for full event samples are observed to obey Koba, Nielsen and Olesen (KNO) scaling. The trends of variations of scaled variance with beam energy are also found to support the KNO scaling predictions for larger collision centrality. The findings also reveal that the statistical fluctuations in 5\% centrality-bin width appear to be under control.

nucl-th↗

arXiv2019

Contributions of Jets in Net Charge Fluctuations from the Beam Energy Scan at RHIC and LHC

Dynamical net charge fluctuations have been studied in ultra-relativistic heavy-ion collisions from the beam energy scan at RHIC and LHC energies by carrying out the hadronic model simulation. Monte Carlo model, HIJING is used to generate events in two different modes, HIJING-default with jet quenching switched off and jet/minijet production switched off. A popular variable, $ν_{[+-,dyn]}$ is used to study the net charge fluctuations in different centrality bins and the findings are compared with the available experimental values reported earlier. Although the broad features of net charge fluctuations are reproduced by the HIJING, yet the model predicts the larger magnitude of fluctuations as compared to the one observed in experiments. The role of jets/minijets production in reducing the net charge fluctuations is, however distinctly visible from the analysis of the two types of HIJING events. Furthermore, $dN_{ch}/dη$ and $1/N$ scaling is partially exhibited which is due to the fact that in HIJING, nucleus-nucleus collisions are treated as multiple independent nucleon-nucleon collisions.

hep-ph↗

arXiv2019

Event-by-Event Fluctuations Clusterization and Entropy Production in AA Collisions at AGS and SPS Energies

Event-by-event (ebe) fluctuations in mean pseudorapidity values of relativistic charged particles in full phase space is studied by analysing experimental data on $^{16}O-AgBr$ collisions at 14.5A, 60A, and 200A GeV/c and $^{32}S-AgBr$ collisions at 200A GeV/c. The findings are compared with the prediction of A Multi-Phase Transport(\amm) model and those obtained from the analysis of correlation free Monte-Carlo events. Fluctuations in mean pseudorapidity distributions are noticed to be in excess to that expected from the statistically independent particle emission. The observed dependence of the fluctuation strength measure parameter,$ϕ$ on the beam energy and number of participating target nucleons indicate that nucleus-nucleus collisions can not be treated as simple superposition of multiple nucleon-nucleon interactions. Presence of clusters or jet-like phenomena in multihadron final states are searched for on ebe basis by using the concept of Jaynes Shannon entropy. The findings indicate the presence of cluster like objects in the experimental data with their size and frequency increasing with increasing beam energy. These observations, in turn suggest that the clustering or jet-like algorithm adopted in the present study may be used as a tool for triggering different classes of events.

hep-ph↗

arXiv2018

Correlations and Event-by-Event Fluctuations in High Multiplicity Events Produced in $^{208}$Pb-$^{208}$Pb Collisions

Analysis of high multiplicity events produced in 158A GeV/c $^{208}$Pb-$^{208}$Pb collisions is carried out to study the event-by-event fluctuations. The findings reveal that the method of scaled factorial moments can be used to identify the events having densely populated narrow phase space bins. A few events sorted out adopting this approach are individually analyzed. It is observed that these events do exhibit large fluctuations in their pseudorapidity, $η$ and azimuthal angle, $ϕ$ distributions arising out due to some dynamical reasons. Two particle $Δη$-$Δϕ$ correlation study applied to these events too indicates that some complex two-dimensional structure of significantly high magnitude are present in these events which might have some dynamical origin. The findings reveal that the method of scaled factorial moments may be used as an effective triggering for events with large dynamical fluctuations.

hep-ex↗

arXiv2018

Multifractal Characteristics of Multiparticle Production in Heavy-Ion Collisions at SPS Energies

Entropy, dimensions and other multifractal characteristics of multiplicity distributions of relativistic charged hadrons produced in ion-ion collisions at SPS energies are investigated. The analysis of the experimental data is carried out in terms of phase space bin-size dependence of multiplicity distributions following the Takagi's approach. Yet another method is also followed to study the multifractality which, is not related to the bin-width and (or) the detector resolution, rather involves multiplicity distribution of charged particles in full phase space in terms of information entropy and its generalization, Rényi's order-q information entropy. The findings reveal the presence of multifractal structure-- a remarkable property of the fluctuations. Nearly constant values of multifractal specific heat, 'c' estimated by the two different methods of analysis followed indicate that the parameter 'c' may be used as a universal characteristic of the particle production in high energy collisions. The results obtained from the analysis of the experimental data agree well with the predictions of Monte Carlo model AMPT.

hep-ph↗

arXiv2017

Entropy and Multifractality in Relativistic Ion-Ion Collisions

Entropy production in multiparticle systems is investigated by analysing the experimental data on ion-ion collision at AGS and SPS energies and comparing the findings with those reported earlier for hadron-hadron, hadron-nucleus and nucleus-nucleus collisions. It is observed that the entropy produced in limited and full phase space, when normalised to maximum rapidity exhibits a kind of scaling which is nicely supported by Monte Carlo model \hij. Using the Rényi's order-q information entropy, multifractal characteristics of particle production are examined in terms of Generalized dimensions, D$_{q}$. Nearly the same values of multifractal specific heat, $c$ observed in hadronic and ion-ion collisions over a wide range of incident energies suggest that the quantity $c$ may be used as a universal characteristic of multiparticle production in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions.

hep-ph↗

arXiv2016

Lexical Based Semantic Orientation of Online Customer Reviews and Blogs

Rapid increase in internet users along with growing power of online review sites and social media has given birth to sentiment analysis or opinion mining, which aims at determining what other people think and comment. Sentiments or Opinions contain public generated content about products, services, policies and politics. People are usually interested to seek positive and negative opinions containing likes and dislikes, shared by users for features of particular product or service. This paper proposed sentence-level lexical based domain independent sentiment classification method for different types of data such as reviews and blogs. The proposed method is based on general lexicons i.e. WordNet, SentiWordNet and user defined lexical dictionaries for semantic orientation. The relations and glosses of these dictionaries provide solution to the domain portability problem. The method performs better than word and text level corpus based machine learning methods for semantic orientation. The results show the proposed method performs better as it shows precision of 87% and83% at document and sentence levels respectively for online comments.

cs.CL↗

arXiv2015

Sentiment Analysis on YouTube: A Brief Survey

Sentiment analysis or opinion mining is the field of study related to analyze opinions, sentiments, evaluations, attitudes, and emotions of users which they express on social media and other online resources. The revolution of social media sites has also attracted the users towards video sharing sites, such as YouTube. The online users express their opinions or sentiments on the videos that they watch on such sites. This paper presents a brief survey of techniques to analyze opinions posted by users about a particular video.

cs.SI↗

arXiv2015

Event by Event Analysis of High Multiplicity Events Produced in 158 A GeV/c 208 Pb- 208 Pb Collisions

An extensive analysis of individual high multiplicity events produced in 158 A GeV /c 208Pb- 208Pb collisions is carried by adopting different methods to examine the anomalous behavior of these rare events. A method of selecting the events with densely populated narrow regions or spikes out of a given sample of collision events is discussed.Employing this approach two events with large spikes in their eta- and phi- distributions are selected for further analysis. For the sake of comparison, another two events which do not exhibit such spikes are simultaneously analyzed. The findings suggest that the systematic studies of particle density fluctuations in one- and two-dimensional phase-spaces and comparison with those obtained from the studies of correlation free Monte Carlo events, would be useful for identifying the events with large dynamical fluctuations. Formation of clusters or jet like phenomena in multihadronic final states in individual events is also discussed and the experimental findings are compared with the independent particle emission hypothesis by carrying out Monte Carlo simulations.

nucl-ex↗

arXiv2015

Search for Long-Range Correlations in Relativistic Heavy-Ion Collisions at SPS Energies

Long range correlations are searched for by analyzing the experimental data on 16O-AgBr and 32S-AgBr collisions at 200A GeV/c and the results are compared with the predictions of a multi phase transport (AMPT) model. The findings reveal that the observed forward-backward (F-B) multiplicity correlations are mainly of short-range in nature. The range of F-B correlations are observed to extend with increasing projectile mass. The observed extended range of F-B correlations might be due to overall multiplicity fluctuations arising because of nuclear geometry. The findings are not sufficient for making any definite conclusions regarding the presence of long-range correlations.

nucl-ex↗

arXiv2015

A study of event-by-event fluctuations in relativistic heavy-ion collisions

A method for selecting events with densely populated narrow regions or spikes in a given data sample is discussed. Applying this method to 200 A GeV/c 32S-AgBr and 32S-Gold collision data, a few events having "hot regions" are chosen for further analysis. The finding reveals that a systematic study of particle density fluctuations, if carried out in terms of scaled factorial moments, and the results are compared with those for the analysis of correlation free Monte Carlo events, would be useful in identifying events with large dynamical fluctuations. Formation of clusters or jet-like structure in multihadronic final states in the selected spiky events is also looked into and compared with the predictions of AMPT and independent emission hypothesis models by carrying out Monte Carlo simulation. The findings suggest that clustering or jet-like algorithm adopted in the present study may also serve as an important tool for triggering different classes of events.

nucl-ex↗

arXiv2015

A Study of Fluctuations of Voids in Relativistic Ion-Ion Collisions

Event-by-event fluctuations (ebe) of hadronic patterns are investigated in terms of voids by analyzing the experimental data on 4.5, 14.5 and 60A GeV/c 16O-AgBr collisions. The findings are compared with the predictions of a multi-phase transport AMPT model. Dependence of voids on phase space bin width is examined in terms of two lowest moments of event-by-event fluctuations of voids, and Sq. The findings reveal that scaling exponent estimated from the observed power-law behavior of the voids may be used to characterize the various properties of hadronic phase transition. The results also rule out occurrence of 2nd order quark-hadron phase transition at the projectile energies considered.

nucl-ex↗

arXiv2011

Automatic Vehicle Checking Agent (VCA)

A definition of intelligence is given in terms of performance that can be quantitatively measured. In this study, we have presented a conceptual model of Intelligent Agent System for Automatic Vehicle Checking Agent (VCA). To achieve this goal, we have introduced several kinds of agents that exhibit intelligent features. These are the Management agent, internal agent, External Agent, Watcher agent and Report agent. Metrics and measurements are suggested for evaluating the performance of Automatic Vehicle Checking Agent (VCA). Calibrate data and test facilities are suggested to facilitate the development of intelligent systems.

cs.AI↗

arXiv2010

Mapping of SOA and RUP: DOA as Case Study

SOA (Service Oriented Architecture) is a new trend towards increasing the profit margins in an organization due to incorporating business services to business practices. Rational Unified Process (RUP) is a unified method planning form for large business applications that provides a language for describing method content and processes. The well defined mapping of SOA and RUP leads to successful completion of RUP software projects to provide services to their users. DOA (Digital Office Assistant) is a multi user SOA type application that provides appropriate viewer for each user to assist him through services. In this paper authors proposed the mapping strategy of SOA with RUP by considering DOA as case study.

cs.SE↗

arXiv2010

Improvement in RUP Project Management via Service Monitoring: Best Practice of SOA

Management of project planning, monitoring, scheduling, estimation and risk management are critical issues faced by a project manager during development life cycle of software. In RUP, project management is considered as core discipline whose activities are carried in all phases during development of software products. On other side service monitoring is considered as best practice of SOA which leads to availability, auditing, debugging and tracing process. In this paper, authors define a strategy to incorporate the service monitoring of SOA into RUP to improve the artifacts of project management activities. Moreover, the authors define the rules to implement the features of service monitoring, which help the project manager to carry on activities in well define manner. Proposed frame work is implemented on RB (Resuming Bank) application and obtained improved results on PM (Project Management) work.

cs.SE↗

arXiv2010

Mapping The Best Practices of XP and Project Management: Well defined approach for Project Manager

Software engineering is one of the most recent additions in various disciplines of system engineering. It has emerged as a key obedience of system engineering in a quick succession of time. Various Software Engineering approaches are followed in order to produce comprehensive software solutions of affordable cost with reasonable delivery timeframe with less uncertainty. All these objectives are only satisfied when project's status is properly monitored and controlled; eXtreme Programming (XP) uses the best practices of AGILE methodology and helps in development of small size software very sharply. In this paper, authors proposed that via XP, high quality software with less uncertainty and under estimated cost can be developed due to proper monitoring and controlling of project. Moreover, authors give guidelines that how activities of project management can be embedded into development life cycle of XP to enhance the quality of software products and reduce the uncertainty.

cs.SE↗

arXiv2010

E-Courseware Design and Implementation Issues and Strategies

Over the last few years electronic learning has been in use mostly by corporate institutes in the form of computer aided instructions and computer based training. The scope of such use has not only been limited to introductory courses for beginners and working people but also to impart knowledge in higher education sector. Due to increasing market demands and current prevailing law and order situation of this area (during which the University remain closed for uncertain period of time on many occasions) Gomal University D.I.Khan, Pakistan is planning to introduce e-learning at undergraduate and post graduate level in computer and management sciences for smooth and uninterrupted delivery of quality education to local and distant students. Obvious result of elearning will be two fold. First it will meet market demands along with smooth uninterrupted delivery of quality education and secondly will solve the growing problem of shortage of experts raised by the current law and order situation. This paper investigates the main issues involved in designing and implementing an effective electronic courseware for students with diverse backgrounds belonging to this remote area. Some effective strategies for electronic delivery of courses to local and distant students are also presented along with some examples of implementation.

cs.CY↗