Performance Analysis of QoS in PMP Mode WiMax Networks

IEEE 802.16 standard supports two different topologies: point to multipoint (PMP) and Mesh. In this paper, a QoS mechanism for point to multipoint of IEEE 802.16 and BS scheduler for PMP Mode is proposed. This paper also describes quality of service over WiMAX networks. Average WiMAX delay, Average WiMAX load and Average WiMAX throughput at base station is analyzed and compared by applying different scheduler at Base station and at fixed nodes

Beta-delayed neutron emission spectroscopy in the 78Ni region and development of YSO-based implantation detector

Decays of Cu isotopes provide a laboratory to study the properties for nearly doubly-magic nuclei with a significant neutron excess which are also relevant for the r-process models. The beta-decay properties of doubly-magic 78Ni (N=50) are imprinted in the neighboring Cu decay, nuclei with a single proton outside the Z=28 core. The investigated isotopes 79,80,81Cu are strong beta-delayed neutron precursors, suggesting that their decay strength distribution lies above neutron separation energies in 79,80,81Zn daughters. For decay studies, a segmented scintillator YSO (Y2SiO5 : Ce doped) based implantation detector was developed at the University of Tennessee, Knoxville. The detector is compact in structure and offers good spatial and timing resolution, crucial for ion-β correlations and time-of-flight (ToF) based β-delayed neutron emission spectroscopy, respectively. The detector was employed as a part of the BRIKEN neutron counter at the Radioactive Isotope Beam Factory (RIBF) at RIKEN Nishina Center in Japan, aiming to measure one- and two- neutron emission probabilities (P n,2n ). for nuclei around the 78Ni region. Another variant of the detector with a more advanced design was used along with VANDLE (Versatile Array for Neutron Detection at Low Energy) to conduct spectroscopy of β-delayed neutrons in the same region. Reconstruction of the feeding intensities requires analysis of neutron-gamma cascades, as is suggested by the statistical model. This work reports the first direct measurements of β-decay strength to neutron-unbound states in the decay of 81, 80, 79Cu. The results from the experiment are compared to shell-model calculations with various sets of single-particle energies and residual interactions. Finally, predictions for 78Ni decay are made based on the model best-describing 79Cu

Using Machine Learning and Graph Mining Approaches to Improve Software Requirements Quality: An Empirical Investigation

Software development is prone to software faults due to the involvement of multiple stakeholders especially during the fuzzy phases (requirements and design). Software inspections are commonly used in industry to detect and fix problems in requirements and design artifacts, thereby mitigating the fault propagation to later phases where the same faults are harder to find and fix. The output of an inspection process is list of faults that are present in software requirements specification document (SRS). The artifact author must manually read through the reviews and differentiate between true-faults and false-positives before fixing the faults. The first goal of this research is to automate the detection of useful vs. non-useful reviews. Next, post-inspection, requirements author has to manually extract key problematic topics from useful reviews that can be mapped to individual requirements in an SRS to identify fault-prone requirements. The second goal of this research is to automate this mapping by employing Key phrase extraction (KPE) algorithms and semantic analysis (SA) approaches to identify fault-prone requirements. During fault-fixations, the author has to manually verify the requirements that could have been impacted by a fix. The third goal of my research is to assist the authors post-inspection to handle change impact analysis (CIA) during fault fixation using NL processing with semantic analysis and mining solutions from graph theory. The selection of quality inspectors during inspections is pertinent to be able to carry out post-inspection tasks accurately. The fourth goal of this research is to identify skilled inspectors using various classification and feature selection approaches. The dissertation has led to the development of automated solution that can identify useful reviews, help identify skilled inspectors, extract most prominent topics/keyphrases from fault logs; and help RE author during the fault-fixation post inspection

Performance Analysis of QoS in PMP Mode WiMax Networks

IEEE 802 16 standard supports two different topologies point to multipoint PMP and Mesh In this paper a QoS mechanism for point to multipoint of IEEE 802 16 and BS scheduler for PMP Mode is proposed This paper also describes quality of service over WiMAX networks Average WiMAX delay Average WiMAX load and Average WiMAX throughput at base station is analyzed and compared by applying different scheduler at Base station and at fixed node

Effects of Aging Time and Sintering Temperatures on Thermal, Structural and Morphological Properties of Coralline Hydroxyapatite

Biphasic Calcium Phosphate bioceramics belong to a group of bone substitute biomaterials comprised of an intimate mixture of Hydroxyapatite (HAP) and β-Tricalcium Phosphates. In the present work, Coralline Hydroxyapatite was synthesized using wet precipitation method. Powder particles were aged for 24 and 48 hours at 5. X-Ray Diffraction, Fourier Transform Infrared and Thermogravimetric spectroscopic techniques were used. Biphasic Calcium Phosphate was identified as the chief structural constitution of the synthetic powders. Weight fraction of Hydroxyapatite increased with the rise of sintering temperature. Aging time of 24 hours yielded maximum amount of hydroxyapatite, thus confirming optimum aging time for the synthesis of Coralline Hydroxyapatite

GNSS Precise Point Positioning Using Low-Cost GNSS Receivers

There are positioning techniques available such as Real-Time Kinematic (RTK) which allow user to obtain few cm-level positioning, but require infrastructure cost, i.e., setting up local or regional networks of base stations to provide corrections. Precise Point Positioning (PPP) using dual-frequency receivers is a popular standalone technique to process GNSS data by applying precise satellite orbit and clock correction along with other corrections to produce cm to dm-level positioning. At the time of writing, almost all low-cost and ultra-low-cost (few $10s) GNSS units are single-frequency chips. Single-frequency PPP poses challenges in terms of effectively mitigating ionospheric delay and the multipath, as there is no second frequency to remove the ionospheric delay. The quality of measurements also deteriorates drastically from geodetic-grade to ultra-low-cost hardware. Given these challenges, this study attempts to improve the performance of single-frequency PPP using geodetic-grade hardware, and to capture the potential positioning performance of this new generation of low-cost and ultra-low-cost GNSS chips. Raw measurement analysis and post-fit residuals show that measurements from cellphones are more prone to multipath compared to signals from geodetic-grade and low-cost receivers. Horizontal accuracy of a few-centimetres is demonstrated with geodetic-grade hardware. Whereas accuracy of few-decimetres is observed from low-cost and ultra-low-cost GNSS hardware. With multi-constellation processing, improvements in accuracy and reductions in convergence time over initial 60 minutes period, are also demonstrated with three different set of GNSS hardware. Horizontal and vertical rms of 37 cm and 51 cm, respectively, is achieved using a cellphone

Comparing the Non-Cystic Fibrosis Bronchiectasis Patients with Non-Tuberculous Mycobacteria (NTM) and Non-NTM Infections

Objective The objective of the study is to compare the Non-Cystic Fibrosis Bronchiectasis patients with Non Tubercular Mycobacteria (NTM) and Non-NTM infection and determine if the NTM and Non-NTM groups are different. Methods Data from the COPD Foundation’s Bronchiectasis Research Registry (BRR) was used in the study (n=1660).Logistic regression, Cox proportional hazards regression, and Kaplan Meier survival analysis were used to analyze the data. Results The study found odds ratio for having NTM infection for age to be 1.02 and for gender to be 2.34, after adjusting for all other variables in the multivariate logistic regression, with the p-value of Conclusion This study, one of the first study done using the BRR’s database found age and gender to be significantly associated with NTM infection, but did not found any difference in survival among patients of the two groups. Further studies need to be done to expand the horizon of this less researched topic