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Multiple ionization and charge equilibration in slow, multiply charged $\mathrm{Ar^{q+} + Ar}$ collision studied via L-MM Auger-Meitner electron spectroscopy
Authors:
Rohit Tyagi,
L. C. Tribedi,
M. K. Harbola,
A. H. Kelkar
Abstract:
We report energy and angle resolved absolute cross section measurements for LMM Auger-Meitner electron emission following collisions of hundred keV protons and $\mathrm{Ar^{3+/6+}}$ ion with an atomic Ar target. The double differential cross section spectra show distinct contributions from target and projectile Auger-Meitner decay. The projectile emission exhibits the expected Doppler shift for va…
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We report energy and angle resolved absolute cross section measurements for LMM Auger-Meitner electron emission following collisions of hundred keV protons and $\mathrm{Ar^{3+/6+}}$ ion with an atomic Ar target. The double differential cross section spectra show distinct contributions from target and projectile Auger-Meitner decay. The projectile emission exhibits the expected Doppler shift for various angles of electron emission, and the measured peak energies are in excellent agreement with kinematic calculations. The energy integrated cross sections show isotropic angular distribution for target and projectile species in their respective rest frames. The Auger-Meitner peak energy for target as well as projectile emission show significant difference in comparison to the characteristic L-MM Auger-Meitner energy peak from atomic Ar. The experimental measurements have been complimented with development of a theoretical model to calculate the transition probabilities corresponding to prominent L-MM Auger-Meitner transitions in neutral and multiply charged Ar atom. Comparison between measured and calculated spectra shows that the measured emission peak at approximately 150 eV originates from Auger-Meitner decay of $\mathrm{Ar^{4+}}$ ions. The peak energies for target and projectile emission are found to be equal, independent of the initial projectile charge state. This indicates that the decay occurs following extensive multiple ionization, charge exchange processes resulting in charge-state equilibration of the collision partners. The results demonstrate that collision-induced electronic rearrangement strongly modifies the Auger-Meitner spectra and provide evidence for an equilibrium target-projectile charge state in low-energy $\mathrm{Ar^{q+} - Ar}$ collisions.
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Submitted 9 August, 2026;
originally announced August 2026.
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CP2K: An electronic structure and molecular dynamics software package - Dynamics, Transport, and Spectroscopic Response
Authors:
Jan Wilhelm,
Anna-Sophia Hehn,
Hossam Elgabarty,
Beliz Sertcan Gökmen,
Maximilian Graml,
Stepan Marek,
Ritaj Tyagi,
Frederick Stein,
Johann V. Potoschnig,
Augustin Bussy,
Christian S. Ahart,
Zehua Chen,
Linnea Andersson,
Zdenek Futera,
Filip Ivanovic,
Margherita Buraschi,
Christoph Schran,
Remi Pasquier,
Leonard Prokisch,
Bibek Samal,
Jelena Schmitz,
Shridhar Sanjay Shanbhag,
Harald Forbert,
Ole Schütt,
Franz Pöschl
, et al. (17 additional authors not shown)
Abstract:
One of the distinguishing aspects of CP2K is its seamless integration of diverse structural and transition-state optimization techniques with advanced sampling approaches including Monte Carlo, molecular dynamics, and metadynamics, enabling the efficient exploration of complex potential- and free-energy landscapes, including rare events. These capabilities are combined with a broad hierarchy of en…
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One of the distinguishing aspects of CP2K is its seamless integration of diverse structural and transition-state optimization techniques with advanced sampling approaches including Monte Carlo, molecular dynamics, and metadynamics, enabling the efficient exploration of complex potential- and free-energy landscapes, including rare events. These capabilities are combined with a broad hierarchy of energy and force evaluation methods, ranging from classical and machine-learned interaction potentials and mixed quantum-classical multiscale and semiempirical schemes, to highly accurate quantum-mechanical electronic-structure approaches. At the heart of the latter lies the Gaussian and plane-wave framework, along with its augmented all-electron generalization, which have been described in detail in our previous code review [T. D. Kühne et al., J. Chem. Phys. 152, 194103 (2020)]. Building on this foundation, the present work revisits the methods within CP2K that turn electronic structure into dynamics, transport, and spectroscopic response. Particular emphasis is placed on the coupling between static response calculations and nuclear motion: spectra may be evaluated at optimized structures, averaged over thermally sampled configurations, obtained from time-correlation functions along ab-initio or path integral molecular trajectories, or followed in real time together with electronic and nuclear dynamics. The same modular structure also enables equilibrium and biased transport simulations, from Kubo-type linear response to open-boundary approaches under external potentials, highlighting CP2K's unique capability to unify quantum chemistry with quantum and statistical mechanics within a versatile, holistic simulation environment.
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Submitted 30 July, 2026; v1 submitted 24 July, 2026;
originally announced July 2026.
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Development of a projectile charge state analyzer and 10 kV bipolar power supply for MeV energy ion - atom/molecule collision experiments
Authors:
Sandeep Bajrangi Bari,
Sahan Raghava Sykam,
Ranojit Das,
Rohit Tyagi,
Aditya H. Kelkar
Abstract:
We have developed a post-collision projectile charge state analyzer (CSA) for detecting the charge state of the projectile ion following ion-atom/molecule collision. The design of the analyzer, based on electrostatic parallel plate deflector was simulated using SIMION ion optics package. We have also developed a 10 kV bipolar programmable power supply to bias the CSA electrodes. The CSA and the po…
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We have developed a post-collision projectile charge state analyzer (CSA) for detecting the charge state of the projectile ion following ion-atom/molecule collision. The design of the analyzer, based on electrostatic parallel plate deflector was simulated using SIMION ion optics package. We have also developed a 10 kV bipolar programmable power supply to bias the CSA electrodes. The CSA and the power supply, both, were tested in collision studies using MeV energy ion beam of proton and carbon ions at the 1.7 MV tandetron accelerator facility at IIT Kanpur.
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Submitted 23 November, 2025;
originally announced November 2025.
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Agentic LLMs for Question Answering over Tabular Data
Authors:
Rishit Tyagi,
Mohit Gupta,
Rahul Bouri
Abstract:
Question Answering over Tabular Data (Table QA) presents unique challenges due to the diverse structure, size, and data types of real-world tables. The SemEval 2025 Task 8 (DataBench) introduced a benchmark composed of large-scale, domain-diverse datasets to evaluate the ability of models to accurately answer structured queries. We propose a Natural Language to SQL (NL-to-SQL) approach leveraging…
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Question Answering over Tabular Data (Table QA) presents unique challenges due to the diverse structure, size, and data types of real-world tables. The SemEval 2025 Task 8 (DataBench) introduced a benchmark composed of large-scale, domain-diverse datasets to evaluate the ability of models to accurately answer structured queries. We propose a Natural Language to SQL (NL-to-SQL) approach leveraging large language models (LLMs) such as GPT-4o, GPT-4o-mini, and DeepSeek v2:16b to generate SQL queries dynamically. Our system follows a multi-stage pipeline involving example selection, SQL query generation, answer extraction, verification, and iterative refinement. Experiments demonstrate the effectiveness of our approach, achieving 70.5\% accuracy on DataBench QA and 71.6\% on DataBench Lite QA, significantly surpassing baseline scores of 26\% and 27\% respectively. This paper details our methodology, experimental results, and alternative approaches, providing insights into the strengths and limitations of LLM-driven Table QA.
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Submitted 11 September, 2025;
originally announced September 2025.
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Improving Narrative Classification and Explanation via Fine Tuned Language Models
Authors:
Rishit Tyagi,
Rahul Bouri,
Mohit Gupta
Abstract:
Understanding covert narratives and implicit messaging is essential for analyzing bias and sentiment. Traditional NLP methods struggle with detecting subtle phrasing and hidden agendas. This study tackles two key challenges: (1) multi-label classification of narratives and sub-narratives in news articles, and (2) generating concise, evidence-based explanations for dominant narratives. We fine-tune…
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Understanding covert narratives and implicit messaging is essential for analyzing bias and sentiment. Traditional NLP methods struggle with detecting subtle phrasing and hidden agendas. This study tackles two key challenges: (1) multi-label classification of narratives and sub-narratives in news articles, and (2) generating concise, evidence-based explanations for dominant narratives. We fine-tune a BERT model with a recall-oriented approach for comprehensive narrative detection, refining predictions using a GPT-4o pipeline for consistency. For narrative explanation, we propose a ReACT (Reasoning + Acting) framework with semantic retrieval-based few-shot prompting, ensuring grounded and relevant justifications. To enhance factual accuracy and reduce hallucinations, we incorporate a structured taxonomy table as an auxiliary knowledge base. Our results show that integrating auxiliary knowledge in prompts improves classification accuracy and justification reliability, with applications in media analysis, education, and intelligence gathering.
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Submitted 4 September, 2025;
originally announced September 2025.
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Magnetic control of an exciton-polariton condensate in a van der Waals magnet
Authors:
Heng Zhang,
Niloufar Nilforoushan,
Christian Weidgans,
Tobias Inzenhofer,
Marlene Liebich,
Josef Riepl,
Julian Hirschmann,
Imke Gronwald,
Kseniia Mosina,
Zdeněk Sofer,
Ritaj Tyagi,
Jan Wilhelm,
Fabian Mooshammer,
Florian Dirnberger,
Rupert Huber
Abstract:
Quasiparticle condensates are among the most spectacular solid-state manifestations of quantum physics. Coupling macroscopic real-space wavefunctions to additional degrees of freedom, such as the electron spin, would add valuable control knobs for quantum applications. While creating spin-carrying superconducting condensates has attracted enormous attention, man-made condensates of light-matter hy…
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Quasiparticle condensates are among the most spectacular solid-state manifestations of quantum physics. Coupling macroscopic real-space wavefunctions to additional degrees of freedom, such as the electron spin, would add valuable control knobs for quantum applications. While creating spin-carrying superconducting condensates has attracted enormous attention, man-made condensates of light-matter hybrids known as exciton-polaritons have lacked an analogous spin-based perspective. Here we open a new door by demonstrating magnetically tunable exciton-polariton condensation in the van der Waals magnet CrSBr. Under photoexcitation, CrSBr microwires embedded in an optical cavity show the hallmarks of polariton condensation: a dramatic increase of the emission intensity from an excited laterally confined polariton state by multiple orders of magnitude, spectral narrowing of the emission line, and a continuous shift of the peak energy. Interferometry evidences an increase in spatial and temporal coherence. Owing to the strong coupling between the spin order and excitonic correlation, the energy of the condensate can be tuned by up to 10.5 meV by an external magnetic field of only 2 Tesla. Our results establish CrSBr microcavities as a powerful platform for exploring magnetic control of polariton condensates and mark a significant step toward spin-controlled coherent quantum light sources.
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Submitted 13 June, 2026; v1 submitted 6 June, 2025;
originally announced June 2025.
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Momentum imaging and kinetic energy release measurements for various fragmentation pathways in MeV energy proton collision with $SO_2$ molecule
Authors:
Sandeep Bajrangi Bari,
Ranojit Das,
Rohit Tyagi,
Aditya H. Kelkar
Abstract:
We have studied the ionization and fragmentation of $SO_2$ molecular target in collision with 1 MeV proton beam using the technique of recoil ion momentum spectroscopy. Fragmentation dynamics of doubly charged $SO_2^{2+}$ molecular ion has been investigated in detail using Dalitz plot and Newton diagrams. We have identified concerted and sequential dissociation pathways in three body dissociation…
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We have studied the ionization and fragmentation of $SO_2$ molecular target in collision with 1 MeV proton beam using the technique of recoil ion momentum spectroscopy. Fragmentation dynamics of doubly charged $SO_2^{2+}$ molecular ion has been investigated in detail using Dalitz plot and Newton diagrams. We have identified concerted and sequential dissociation pathways in three body dissociation of the parent molecular ion. 3D momentum distribution of all fragment particles, including the neutral atom, were obtained along with the kinetic energy release spectra for various fragmentation channels.
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Submitted 6 April, 2025;
originally announced April 2025.
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Harmonic Loss Trains Interpretable AI Models
Authors:
David D. Baek,
Ziming Liu,
Riya Tyagi,
Max Tegmark
Abstract:
In this paper, we introduce harmonic loss as an alternative supervisory signal for training neural networks and large language models (LLMs). Harmonic loss differs from standard cross-entropy loss by (a) replacing the usual SoftMax normalization with a scale-invariant HarMax function and (b) computing logits via Euclidean distance rather than a dot product. Harmonic loss enables improved interpret…
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In this paper, we introduce harmonic loss as an alternative supervisory signal for training neural networks and large language models (LLMs). Harmonic loss differs from standard cross-entropy loss by (a) replacing the usual SoftMax normalization with a scale-invariant HarMax function and (b) computing logits via Euclidean distance rather than a dot product. Harmonic loss enables improved interpretability and faster convergence, owing to its scale invariance and finite convergence point by design, which can be interpreted as a class center. We first validate the performance of harmonic models across algorithmic, vision, and language datasets. Through extensive experiments, we demonstrate that models trained with harmonic loss perform better than standard models by: (a) enhancing interpretability, (b) requiring less data for generalization, and (c) reducing grokking. Moreover, we compare a GPT-2 model trained with harmonic loss to the standard GPT-2, illustrating that the harmonic model develops more interpretable representations. Looking forward, we believe harmonic loss may become a valuable tool in domains with limited data availability or in high-stakes applications where interpretability and reliability are paramount, paving the way for more robust and efficient neural network models.
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Submitted 10 July, 2025; v1 submitted 3 February, 2025;
originally announced February 2025.
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Development of a cylindrical mirror analyzer electron spectrometer and associated data acquisition system to study inner shell electron emission following ion-atom collision
Authors:
Rohit Tyagi,
A. H. Kelkar
Abstract:
In this paper we report on the development and performance of a cylindrical mirror analyser electron spectrometer for ion atom collision experiments. A low cost data acquisition system using Arduino microcontroller has also been developed and tested. We have measured the Auger emission spectra for various gaseous targets in collision with 1 MeV proton beams. Relative total Auger emission cross sec…
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In this paper we report on the development and performance of a cylindrical mirror analyser electron spectrometer for ion atom collision experiments. A low cost data acquisition system using Arduino microcontroller has also been developed and tested. We have measured the Auger emission spectra for various gaseous targets in collision with 1 MeV proton beams. Relative total Auger emission cross sections have also been measured for N2 molecular target as a function of proton energy.
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Submitted 19 February, 2024;
originally announced February 2024.
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L-MM Auger electron emission from chlorinated organic molecules under proton impact: angular distribution and total cross section measurement
Authors:
Rohit Tyagi,
Abhijeet Bhogale,
Sandeep Bari,
L. C. Tribedi,
A. H. Kelkar
Abstract:
We have measured absolute total cross section for LMM Auger electron emission of Cl in chlorinated methane and benzene chloride in collision with H+ ion. Projectile energy dependence of the total yield as well as the angular distribution has been studied. Incident proton energy has been varied from 125 keV to 275 keV in steps of 50 keV. C KLL Auger yield have been compared with previous studies an…
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We have measured absolute total cross section for LMM Auger electron emission of Cl in chlorinated methane and benzene chloride in collision with H+ ion. Projectile energy dependence of the total yield as well as the angular distribution has been studied. Incident proton energy has been varied from 125 keV to 275 keV in steps of 50 keV. C KLL Auger yield have been compared with previous studies and found to be in agreement within the effect of chemical species It has been found that the LMM Auger yield of Cl is much more significantly affected by molecular environment than the C KLL.
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Submitted 26 May, 2023;
originally announced May 2023.
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Design and characterization of a recoil ion momentum spectrometer for investigating molecular fragmentation dynamics upon MeV energy ion impact ionization
Authors:
Avijit Duley,
Rohit Tyagi,
Sandeep B. Bari,
A. H. Kelkar
Abstract:
We present the development and performance of a newly built recoil ion momentum spectrometer to study the fragmentation dynamics of ionized molecules. The spectrometer is based on the two-stage Wiley-McLaren geometry and satisfies both time and velocity focusing conditions. An electrostatic lens has been introduced in the drift region to achieve velocity imaging and higher angular collection. The…
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We present the development and performance of a newly built recoil ion momentum spectrometer to study the fragmentation dynamics of ionized molecules. The spectrometer is based on the two-stage Wiley-McLaren geometry and satisfies both time and velocity focusing conditions. An electrostatic lens has been introduced in the drift region to achieve velocity imaging and higher angular collection. The spectrometer is equipped with a 2D position-sensitive detector with multi-hit coincidence electronics. Ionic fragments with kinetic energy ~ 8 eV can be detected with 4π collection. The overall performance of the spectrometer has been tested by carrying out three-dimensional ion imaging measurements for diatomic (N$_2$) and polyatomic (CH$_2$Cl$_2$) molecules under the impact of 1 MeV proton. Three-dimensional momentum and kinetic energy release distributions were derived from the measured position and time-of-flight spectra. The observed features of the various fragmentation channels as well as the measured kinetic energy release distributions are in complete agreement with the available data.
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Submitted 13 July, 2022;
originally announced July 2022.
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Machine Learning for Real-Time, Automatic, and Early Diagnosis of Parkinson's Disease by Extracting Signs of Micrographia from Handwriting Images
Authors:
Riya Tyagi,
Tanish Tyagi,
Ming Wang,
Lujin Zhang
Abstract:
Parkinson's disease (PD) is debilitating, progressive, and clinically marked by motor symptoms. As the second most common neurodegenerative disease in the world, it affects over 10 million lives globally. Existing diagnoses methods have limitations, such as the expense of visiting doctors and the challenge of automated early detection, considering that behavioral differences in patients and health…
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Parkinson's disease (PD) is debilitating, progressive, and clinically marked by motor symptoms. As the second most common neurodegenerative disease in the world, it affects over 10 million lives globally. Existing diagnoses methods have limitations, such as the expense of visiting doctors and the challenge of automated early detection, considering that behavioral differences in patients and healthy individuals are often indistinguishable in the early stages. However, micrographia, a handwriting disorder that leads to abnormally small handwriting, tremors, dystonia, and slow movement in the hands and fingers, is commonly observed in the early stages of PD. In this work, we apply machine learning techniques to extract signs of micrographia from drawing samples gathered from two open-source datasets and achieve a predictive accuracy of 94%. This work also sets the foundations for a publicly available and user-friendly web portal that anyone with access to a pen, printer, and phone can use for early PD detection.
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Submitted 24 November, 2021;
originally announced November 2021.
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Search of Secondary Pulsation Modes: Globular cluster (NGC 6496)
Authors:
Gireesh C. Joshi,
R. K. Tyagi
Abstract:
The Fourier-discrete-peridogram are used to identify pulsation modes in variables. We have found two pulsation modes in V1 and V2 among 13 new variables as described by Abbas et al.. The five variables V9 to V13 are not shown close to periodic values by analysis of the frequency distribution of multi-band data and also create difficulty to describe their varied nature. The multi-band periodic valu…
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The Fourier-discrete-peridogram are used to identify pulsation modes in variables. We have found two pulsation modes in V1 and V2 among 13 new variables as described by Abbas et al.. The five variables V9 to V13 are not shown close to periodic values by analysis of the frequency distribution of multi-band data and also create difficulty to describe their varied nature. The multi-band periodic values of V1 and V6 are matched with known literature values. The scattering of the varied nature of secondary pulsation modes is eliminated by moving average methodology. The phase curve of secondary mode is found to be more smooth compared to a prominent mode of pulsation.
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Submitted 29 June, 2016;
originally announced June 2016.
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Statistical analysis for precise estimation of structural properties of NGC 1960
Authors:
Gireesh C. Joshi,
R. K. Tyagi
Abstract:
The statistical analysis of gathered of astronomical objects (such as open cluster) are excellent tools to compute its parameters and to constrain the theory of its evolution. Here, we are represented detailed structural and membership analysis of an open cluster NGC 1960 through various statistical formulas and approaches. King empirical methods provide the information about the cluster extent as…
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The statistical analysis of gathered of astronomical objects (such as open cluster) are excellent tools to compute its parameters and to constrain the theory of its evolution. Here, we are represented detailed structural and membership analysis of an open cluster NGC 1960 through various statistical formulas and approaches. King empirical methods provide the information about the cluster extent as 5.2 +/- 0.4 pc. The exact identification of members of cluster is needed to precise estimation of its age, reddening, metallicity etc., therefore, to identify most probable members (MPMs), we adopted the combined approach of various statistical methods (kinematic, photometric and statistical) and 712 members are satisfied needed criteria of MPMs. The basic physical parameters of the cluster such as E(B-V)=0.23+/-0.02 mag, E(V-K)=1.05+/-0.03mag, log(Age)=7.35+/-0.05, and (m-M)=11.35+/-0.10 mag are obtained using the color-color and color-magnitude diagrams. NGC 1960 is found to be located at a distance of 1.34 +/- 0.03 kpc. Using the archival proper motion catalogues, we estimate mean proper motions of NGC 1960 as 0.83+/-0.26 mas yr-1 and -6.55+/-0.23 mas yr-1 in the direction of RA and DEC, respectively.
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Submitted 24 January, 2016;
originally announced January 2016.
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Dynamical Features of Open Star Cluster: DOLIDZE 14
Authors:
Gireesh C. Joshi,
R. K. Tyagi
Abstract:
The radial density profile (RDP) of cluster DOLIDZE 14 provides the radius of 9.8 arcmin, it is based on consideration of first plateau region of RDP. This value is less than the radius which comes through consideration of the second plateau region. The stars, which are inside of the cluster radius, are used to estimate the distance-modulus and E(I-R) by fitting theoretical isochrone on the colour…
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The radial density profile (RDP) of cluster DOLIDZE 14 provides the radius of 9.8 arcmin, it is based on consideration of first plateau region of RDP. This value is less than the radius which comes through consideration of the second plateau region. The stars, which are inside of the cluster radius, are used to estimate the distance-modulus and E(I-R) by fitting theoretical isochrone on the colour-magnitude diagram (CMD). The best fitted stellar isochrone of solar matellacity provides these values as 11.15 mag and 0.25 mag, respectively. These results are used to estimate the mass-function slope of the cluster, which comes to be different that of Salpeter-Value. The enhancement of brighter stars does not found within the cluster region which indicates its old age. The Mass-Segregation phenomena of cluster is found between massive and lighter stars but not found in fainter stars, having magnitude greater than 15 mag in I-band. The relaxation-time is very little in the comparison of its age. The mean proper motion of cluster's radial zones is found to be high in the comparison of field region (12.77-15.18 arcmin). This is indicative of weak-gravitational bond among the stars of the cluster.
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Submitted 2 December, 2015;
originally announced December 2015.
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Complex stellar system ESO65SC03: Open cluster or remnant?
Authors:
Gireesh C. Joshi,
Y. C. Joshi,
S. Joshi,
S. Chowdhury,
R. K. Tyagi
Abstract:
We present a complete spatial and dynamical study of the poorly populated stellar system ESO65SC03. The radial distribution of the system gives a core and cluster radii of 1.10+/-0.63 arcmin and 5.36+/-0.24 arcmin, respectively. The surface number density profile (SNDP) does not show any clear enhancement of the surface stellar number density between the stars of the system and the field regions.…
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We present a complete spatial and dynamical study of the poorly populated stellar system ESO65SC03. The radial distribution of the system gives a core and cluster radii of 1.10+/-0.63 arcmin and 5.36+/-0.24 arcmin, respectively. The surface number density profile (SNDP) does not show any clear enhancement of the surface stellar number density between the stars of the system and the field regions. We derive the optimum isochrone solution for a particular grid size in the colour-magnitude diagram (CMD) using the statistical cleaning procedure. Using the statistically cleaned CMDs, we find the distance modulus, (m-M)_0, and reddening, E({B-V}), of the system to be 11.8+/-0.2 mag and 0.45 mag, respectively. The mean proper motion of this system is -5.37+/-0.81 mas/yr and 0.31+/-0.40 in RA and DEC directions, respectively. The mean proper motion of this system is found to be almost similar to the field region. The mass function for the brighter stars is found to be too high for the system to be an open cluster. These combined results place constraints on whether stellar system ESO65SC03 is a possible open star cluster remnant (POCR) or an Asterism. Our understanding is that the ESO65SC03 is in a stage of POCR by loosing their main sequence stars in the dynamic evolution processes.
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Submitted 12 May, 2015;
originally announced May 2015.
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Basic Parameters of Open Star Clusters DOLIDZE 14 and NGC 110 in Infrared bands
Authors:
Gireesh C. Joshi,
Y. C. Joshi,
S. Joshi,
R. K. Tyagi
Abstract:
The basic physical parameters of a poorly studied open cluster NGC 110 and an unstudied open cluster DOLIDZE 14 are estimated in the present study using the archival PPMXL and WISE catalogues. The radius of both the clusters are estimated by fitting the modified King's empirical model on their stellar density profiles. The other basic parameters of the clusters such as distance, reddening, and age…
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The basic physical parameters of a poorly studied open cluster NGC 110 and an unstudied open cluster DOLIDZE 14 are estimated in the present study using the archival PPMXL and WISE catalogues. The radius of both the clusters are estimated by fitting the modified King's empirical model on their stellar density profiles. The other basic parameters of the clusters such as distance, reddening, and age are obtained by visual fitting of the Marigo's solar metallicity isochrone on their IR colour-magnitude diagrams (CMDs). The mean-proper motion of the clusters are estimated through the individual proper motion of probable members identified through the dynamical and statistical methods. The archival catalogues (JHKW1W2) are constructed for both the clusters by compiling the extracted data from the PPMXL and WISE catalogues. The various colour-excesses, such as E(J-H), E(H-K) and E(W1-W2), are estimated using the best fit theoretical isochrone on the (J-H)-H, (H-K)-H and (W1-W2)-H CMDs, respectively. The ratios of various infrared colours of the clusters are obtained through their two-colour diagrams. We also identify the most probable members in these clusters by estimating spatial, kinematic and spatio-kinematic probabilities of stars within the cluster. A correlation between the E(H-K) and E(W1-W2) is also established.
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Submitted 11 May, 2015;
originally announced May 2015.
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Aspect Based Sentiment Analysis to Extract Meticulous Opinion Value
Authors:
Deepali Virmani,
Vikrant Malhotra,
Ridhi Tyagi
Abstract:
Opinion Mining and Sentiment Analysis is a process of identifying opinions in large unstructured/structured data and then analysing polarity of those opinions. Opinion mining and sentiment analysis have found vast application in analysing online ratings, analysing product based reviews, e-governance, and managing hostile content over the internet. This paper proposes an algorithm to implement aspe…
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Opinion Mining and Sentiment Analysis is a process of identifying opinions in large unstructured/structured data and then analysing polarity of those opinions. Opinion mining and sentiment analysis have found vast application in analysing online ratings, analysing product based reviews, e-governance, and managing hostile content over the internet. This paper proposes an algorithm to implement aspect level sentiment analysis. The algorithm takes input from the remarks submitted by various teachers of a student. An aspect tree is formed which has various levels and weights are assigned to each branch to identify level of aspect. Aspect value is calculated by the algorithm by means of the proposed aspect tree. Dictionary based method is implemented to evaluate the polarity of the remark. The algorithm returns the aspect value clubbed with opinion value and sentiment value which helps in concluding the summarized value of remark.
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Submitted 29 May, 2014;
originally announced May 2014.
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Sentiment Analysis Using Collaborated Opinion Mining
Authors:
Deepali Virmani,
Vikrant Malhotra,
Ridhi Tyagi
Abstract:
Opinion mining and Sentiment analysis have emerged as a field of study since the widespread of World Wide Web and internet. Opinion refers to extraction of those lines or phrase in the raw and huge data which express an opinion. Sentiment analysis on the other hand identifies the polarity of the opinion being extracted. In this paper we propose the sentiment analysis in collaboration with opinion…
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Opinion mining and Sentiment analysis have emerged as a field of study since the widespread of World Wide Web and internet. Opinion refers to extraction of those lines or phrase in the raw and huge data which express an opinion. Sentiment analysis on the other hand identifies the polarity of the opinion being extracted. In this paper we propose the sentiment analysis in collaboration with opinion extraction, summarization, and tracking the records of the students. The paper modifies the existing algorithm in order to obtain the collaborated opinion about the students. The resultant opinion is represented as very high, high, moderate, low and very low. The paper is based on a case study where teachers give their remarks about the students and by applying the proposed sentiment analysis algorithm the opinion is extracted and represented.
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Submitted 12 January, 2014;
originally announced January 2014.