Papers by Pankaj Choudhary
Online network systems have become popular in many social, biological and information system in r... more Online network systems have become popular in many social, biological and information system in recent year. Much research has been done in social network, which is increasingly growing and form a large complex network. Social network such as Facebook provides a platform for users to share their interest, photos & post etc with their friend. A social network can be well described by a network graph, in which node represents users and edges between nodes represent some association. In most social network links are dynamics and change over the time in network. To predict an association between two nodes in a graph, which is likely to be occur in near future and is termed as link prediction. Many approach and method have been used for predicting a link in past years, a significant interest of the methods uses local and global structure of the graph to make predictions. In this survey we are highlighting the impact of time in association (collaboration or interaction) & temporal behavio...
Short Answer Type Discussion Forum Analysis and Assessment
2020 International Conference for Emerging Technology (INCET), 2020
A recent research study on the online discussion forum shows significant improvement in the learn... more A recent research study on the online discussion forum shows significant improvement in the learning growth of students. The discussion forum is a very useful pedagogical tool and plays a very important role in providing interaction among the participant in online courses. The study shows the use of discussion forums in the online course helps the participant in the better learning experience and improved critical thinking through collaborative learning, the course performance, and the cognitive presence is also increased. The researcher suggests that the discussion forum should be the part assessment tool. This paper investigates the use of a question answer type of discussion forum for the assessment of student posts based on the content analysis and the relevance of content to the discussion topic. A similarity measure is calculated for assigning the grade to the student answer and the result is compared with the teacher grade shows the significant results.
Advances in Applied Ceramics, 2018
Barium strontium titanate (Ba (1−x) Sr x TiO 3 where, x = 0.0, 0.2, 0.3, 0.4 and 0.5) nanoparticl... more Barium strontium titanate (Ba (1−x) Sr x TiO 3 where, x = 0.0, 0.2, 0.3, 0.4 and 0.5) nanoparticles have been successfully synthesised by sol-gel method and characterised thoroughly. With the increase in Sr concentration (x > 0.3), the symmetry of the crystal structure changed from tetragonal to cubic phase. The dielectric behaviour of the ceramic nanoparticles was evaluated using impedance analyser with an operating frequency of 1 Hz to 1 MHz. A very high dielectric constant 4915 was obtained for Ba 0.7 Sr 0.3 TiO 3 at 1 Hz frequency with low dielectric loss of 1.91, which showed very good value than the one previously reported. The density of the material was found to be >98% of theoretical density. Dielectric constants were measured by varying the temperature from 35 to 150°C and the Curie temperatures were also evaluated. The small amount of Sr doping was beneficial for obtaining high dielectric constant material which can be used in various electronic applications.
DAE SOLID STATE PHYSICS SYMPOSIUM 2018, 2019
Spinel Co 1-x Cu x Al 2 O 4 (x = 0.0, 0.5) aluminates were successfully synthesized by wet chemic... more Spinel Co 1-x Cu x Al 2 O 4 (x = 0.0, 0.5) aluminates were successfully synthesized by wet chemical based sol-gel auto combustion route. Final ash powder is annealed at 800 °C for 8 h to obtain nano-blue pigments. X-ray diffraction confirms that all pigments are well crystalline and correspond to normal cubic spinel structure with space group Fd3m. Average crystallite size (< 50 nm) is estimated by Williamson-Hall plot. Influence of Cu 2+ ions on pristine CoAl 2 O 4 , shifts the lower wavenumber modes to higher wavenumber from 464.82 to 475.09 cm-1. The absorption bands around ~ 551, 590 and 652 nm in the UV-Vis spectra occur due to spin-allowed electronic transitions [ 4 A 2 (F) → 4 T 1 (P)] in Co 2+ occupied at tetrahedral (T d)-site. This electronic d-d transition exhibits the pigments with a blue chroma. Direct band gap of CoAl 2 O 4 and Co 0.5 Cu 0.5 Al 2 O 4 pigments were found to be 2.91 and 3.50 eV respectively estimated by Tauc plot.
Journal of Magnetism and Magnetic Materials, 2018
Co 2+ doped Mg-Zn spinel chromite compositions Mg 0.5 Zn 0.5-x Co x Cr 2 O 4 (0.0 ≤ x ≤ 0.5) have... more Co 2+ doped Mg-Zn spinel chromite compositions Mg 0.5 Zn 0.5-x Co x Cr 2 O 4 (0.0 ≤ x ≤ 0.5) have been synthesized by the high-temperature solid state method. Synchrotron and X-ray diffraction (XRD) studies show single-phase crystalline nature. The structural analysis is validated by Rietveld refinement confirms the cubic structure with space group Fd3m. Crystallite size is estimated from Synchrotron XRD which was found to be 30-34 nm. Energy dispersive analysis confirms stoichiometric Mg 0.5 Zn 0.5-x Co x Cr 2 O 4 composition. Average crystallite size distribution is estimated from imaging software (Image-J) of SEM is in the range of 100-250 nm. Raman spectroscopy reveals four active phonon modes, and a pronounced red shift is due to enhanced Co 2+ concentration. Increased Co 2+ concentration in Mg-Zn chromites shows a prominent narrowing of band gap from 3.46 to 2.97 eV. The dielectric response is attributed to the interfacial polarization, and the electrical modulus study supports non-Debye type of dielectric relaxation. Ohmic junctions (minimum potential drop) at electrode interface are active at lower levels of doping (x < 0.2) give rise to a low-frequency semicircle as evidenced from the complex impedance analysis. The low dielectric loss and high ac conductivity of Co 2+ doped Mg-Zn spinel chromites are suitable for power transformer applications at high frequencies.
International Journal of Network Security & Its Applications, 2013
Now a days, a new family of web applications 'open applications', are emerging (e.g., Social Netw... more Now a days, a new family of web applications 'open applications', are emerging (e.g., Social Networking, News and Blogging). Generally, these open applications are non-confidential. The security needs of these applications are only client/server authentication and data integrity. For securing these open applications, effectively and efficiently, HTTPI, a new transport protocol is proposed, which ensures the entire security requirements of open applications. Benefit of using the HTTPI is that it is economical in use, well-suited for cache proxies, like HTTP is, and provides security against many Internet attacks (Server Impersonation and Message Modification) like HTTPS does. In terms of performance HTTPI is very close to the HTTP, but much better than HTTPS. A Web service is a method of communication between two ends over the Internet. These web services are developed over XML and HTTP. Today, most of the open applications use web services for most of their operations. For securing these web services, security design based on HTTPI is proposed. Our work involves securing the web services over SOAP, based on the HTTPI. This secure web service might be applicable for open applications, where authentication and integrity is needed, but no confidentiality required. In our paper, we introduce a web service security model based on HTTPI protocol over SOAP and develop a preliminary implementation of this model. We also analyze the performance of our approach through an experiment and show that our proposed approach provides higher throughput, lower average response time and lower response size than HTTPS based web service security approach.
Statistics in Medicine, 2015
Measurement error models offer a flexible framework for modeling data collected in studies compar... more Measurement error models offer a flexible framework for modeling data collected in studies comparing methods of quantitative measurement. These models generally make two simplifying assumptions: (a) the measurements are homoscedastic; and (b) the unobservable true values of the methods are linearly related. One or both of these assumptions may be violated in practice. In particular, error variabilities of the methods may depend on the magnitude of measurement or the true values may be nonlinearly related. Data with these features call for a heteroscedastic measurement error model that allows nonlinear relationships in the true values. We present such a model for the case when the measurements are replicated, discuss its fitting, and explain how to evaluate similarity of measurement methods and agreement between them, which are two common goals of data analysis, under this model. Model fitting involves dealing with lack of a closed form for the likelihood function. We consider estimation
Ajuste y Reforma en Argentina (1989-1995): La economía política de las privatizaciones
Indian Journal of Ophthalmology, 2011
Fungal species wise comparison of mean MIC of natamycin with treatment outcome was made among the... more Fungal species wise comparison of mean MIC of natamycin with treatment outcome was made among the patients with early and late onset disease [Table 1]. A. fl avus (n = 13) showed the highest mean MIC (early-17.7 μg/ml, late-20.0 μg/ml)
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Papers by Pankaj Choudhary