SFXTs versus classical SgXBs: Does the difference lie in the companion wind?

We present a comparative study of stellar winds in classical supergiant high mass X-ray binaries (SgXBs) and supergiant fast X-ray transients (SFXTs) based on the analysis of publicly available out-of-eclipse observations performed with Suzaku and XMM-Newton. Our data-set includes 55 observations of classical SgXBs and 21 observations of SFXTs. We found that classical SgXBs are characterized by a systematically higher absorption and luminosity compared to the SFXTs, confirming the results of previous works in the literature. Additionally, we show that the equivalent width of the fluorescence K{\alpha} iron line in the classical SgXBs is significantly larger than that of the SFXTs (outside X-ray eclipses). Based on our current understanding of the physics of accretion in these systems, we conclude that the most likely explanation of these differences is to be ascribed to the presence of mechanisms inhibiting accretion for most of the time in the SFXTs and leading to a much less efficient photoionization of the stellar wind compared to classical SgXBs.We do not find evidence for the previously reported anti-correlation between the equivalent width of the fluorescence iron line and the luminosity of SgXBs.Comment: 12 pages, 8 figures, 2 tables, Accepted for publication in A&

Variations of the harmonic components of the X-ray Pulse Profile of PSR B1509-58

We used the Fourier decomposition technique to investigate the stability of the X-ray pulse profile of a young pulsar PSR B1509-58 by studying the relative amplitudes and the phase differences of its harmonic components with respect to the fundamental using data from the Rossi X-Ray Timing Explorer. Like most young rotation powered pulsars, PSR B1509-58 has a high spin down rate. It also has less timing noise allowing accurate measurement of higher order frequency derivatives which in turn helps in study of the physics of pulsar spin down. Detailed investigation of pulse profiles over the years will help us establish any possible connection between the timing characteristics and the high energy emission characteristics for this pulsar. Further, the study of pulse profiles of short period X-ray pulsars can also be useful for using them as means of interplanetary navigation system. The X-ray pulse profile of this source has been analysed for 15 $\rm years$ (1996-2011). The long term average amplitudes of the first, second and third harmonics (and their standard deviation for individual measurements) compared to the fundamental are 36.9 % (1.7 %), 13.4 % (1.9 %) and 9.4 % (1.8 %) respectively. Similarly, the phases of the three harmonics (and standard deviations) with respect to the fundamental are 0.36 (0.06), 1.5 (0.2), 2.5 (0.3) $\rm radian$ respectively. We do not find any significant variation of the harmonic components of the pulse profile in comparison to the fundamental.Comment: 10 pages, 7 figure

Autonomous Botnet Detection

With the pervasiveness of internet, huge threats have been seen in last few decades. These threats involve the activities for violation of security in terms of integrity, confidentiality, denial of service, authentication. Due to the existence of such threats, there is requirement to defend our immense corporate secret, online banking account details and social networking account accessible via web interface. Over last few decades there is the emergence of botnet within internet. Botnet can be considered as the mass of compromise machine that are under the authority and control of single botmaster. Because of existence of such botnet there arouse intrusion. And hence intrusion detection has turn out to be sphere of influence of information assurance. At the network-level, the research work to detect bots has proceeded along two important area of vertical and horizontal correlation engine. Vertical and local correlation engine have the downside that these systems require prior knowledge about communication channel and it is indispensable to have at least two hosts in the monitored network(s) should be the members of the same botnet. Hence the new autonomous model is proposed by combining the concept of observation of command and responses received. This model will be built in controlled environment with recording of network activity by using subspace and evidence accumulation clustering. Proposed models are helpful for detection of bots in the midst of few false positives. Keywords: : Intrusion; intrusion detection system; botnet; threat; evidence accumulation; subspace clusterin

Technology, Institutions and Their Interactions: How Do These Explain E-Participation Degree and Levels? A Cross-Country Analysis

This dissertation aims at explaining the difference in the degree of e-participation across countries using institution and technology variables. It further looks at how the factors differ in their influence across the three levels of e-information, e-consultation, and e-decision making. Institutional and technology variables are identified using the literature review of offline and online public participation (or e-participation). Using the policy feedback theory and Giddens’ structuration theory a conceptual model depicting the complex relationship between institutional and technology variables is developed. The dimensions of digital divide, namely ICT affordability and skills, are found to be the most important explanatory variables. However, the most significant finding of the current study is the role of institutions as the antecedent to technology resources for promoting e-participation. Previous cross-national studies have not looked at this relationship between the institution and technology variable. The results of data analysis inform that ICT affordability and skills in a country act as mediator for the institutions to promote e-participation. At the same time ICT skills and the political rights and civil liberties interact to generate a greater impact on e-participation than their solo effect. Although the magnitude of influence of previous e-participation score increases as one progresses to more complex e-participation levels, but its marginal effect reduces considerably at the advanced level of e-decision making

Electrical Equipment Industry Cluster

The growing collaboration between two or more industries in a specific region in which they work in a symbiotic relationship, providing benefits to each other and contributing in the overall development of the region, is what is popularly known as business clusters. Even though this concept is commonly known and implemented in the West, South Asian economies are unfamiliar with the advantages of this unique business strategy. There are, undeniably, many potential business clusters in these developing countries, which if tapped efficiently, could result into an industrial boom. This research focuses on investigating the existence of a business cluster in the electrical equipment sector in Faridabad, a city that shares its borders with the capital city of India (New Delhi). The research relies on an already developed formula from Professor Fregoso Jasso’s 2010 paper to confirm whether there exists a business cluster or not. Developing of a business cluster in the afore mentioned area would result in increased employment and ultimately, higher living standards for the people of the district

A Conservative Bioadhesive Approach to the Reattachment of Complicated Crown Fractures in Permanent First Molars: A Case Report with a 2-Year Followup

This paper presents a clinical report demonstrating combined restorative bioadhesive treatment and prosthetic rehabilitation of uncommon type of dental injury in an eighteen-year-old female involving crown fracture of all the permanent first molars and left upper premolars due to a bicycle riding accident. To restore the coronal fracture with invasion of biologic width, flap surgery with osteotomy and osteoplasty localized on the fractured teeth was performed, and the tooth remnant was reattached to the crown with a self-etch adhesive system. Frank pulp exposure was treated by self-etch dentin adhesive after surface disinfection prior to sealing of the wound site. At 2-year recall, the teeth continue to be aesthetically and functionally stable with a favourable pulpal and periapical environment