IP Geolocation in Metropolitan Areas

In this thesis, we propose a robust methodology to geolocate a target IP Address in a metropolitan area. We model the problem as a Pattern Recognition problem and present algorithms that can extract patterns and match them for inferring the geographic location of target's IP Address. The first algorithm is a relatively non-invasive method called Pattern Based Geolocation (PBG) which models the distribution of Round Trip Times (RTTs) to a target and matches them to that of the nearby landmarks to deduce the target's location. PBG builds Probability Mass Functions (PMFs) to model the distribution of RTTs. For comparing PMFs, we propose a novel `Shifted Symmetrized Divergence' distance metric which is a modified form of Kullback-Leibler divergence. It is symmetric as well as invariant to shifts. PBG algorithm works in almost stealth mode and leaves almost undetectable signature in network traffic. The second algorithm, Perturbation Augmented PBG (PAPBG), gives a higher resolution in the location estimate using additional perturbation traffic. The goal of this algorithm is to induce a stronger signature of background traffic in the vicinity of the target, and then detect it in the RTT sequences collected. At the cost of being intrusive, this algorithm improves the resolution of PBG by approximately 20-40%. We evaluate the performance of PBG and PAPBG on real data collected from 20 machines distributed over 700 square miles large Washington-Baltimore metropolitan area. We compare the performance of the proposed algorithms with existing measurement based geolocation techniques. Our experiments show that PBG shows marked improvements over current techniques and can geolocate a target IP address to within 2-4 miles of its actual location. And by sending an additional traffic in the network PAPBG improves the resolution to within 1-3 miles

Self inflicted human teeth bites: a case report

Human infighting has been a part of our civilization since times immemorial. These incidences may go unnoticed or may attract attention of law enforcing agencies depending upon the severity of the offence. Though weapons are generally employed to inflict injuries, rare cases have been reported in literature where human teeth have been used to serve this purpose. Human bites may be self inflicted or self suffered in connivance with others to level an allegation against an adversary. We are presenting here such a case where such injuries were produced to bring a false charge against a neighbor

Improvement of both performance and stability of photovoltaic devices by in situ formation of a sulfur-based 2D perovskite

Perovskite solar cells (PSCs) with superior performance have been recognized as a potential candidate in photovoltaic technologies. However, the defects in active perovskite layer induce non-radiative recombination which restricts the performance and stability of the PSCs. The construction of thiophene-based 2D structure is one of the significant approaches for surface passivation of hybrid PSCs that may combine the benefits of the stability of 2D perovskite with the high performance of 3D perovskite. Here, a sulfur-rich spacer cation 2-thiopheneethylamine iodide (TEAI) is synthesized as a passivation agent for the construction of three-dimensional/two-dimensional (3D/2D) perovskite bilayer structure. TEAI-treated PSCs possess a much higher efficiency (20.06%) compared to the 3D perovskite (MAFAPbI3) devices (17.42%). Time-resolved photoluminescence (TRPL) and femtosecond transient absorption (TA) spectroscopy are employed to investigate the effect of surface passivation on the charge carrier dynamics of the 3D perovskite. Additionally, the stability test of TEAI-treated perovskite devices reveals significant improvement in humid (RH ~ 56%) and thermal stability as the sulfur-based 2D (TEA)2PbI4 material self-assembles on the 3D surface making the perovskite surface hydrophobic. Our findings provide a reliable approach to improve device stability and performance successively, paving the way for industrialization of PSCs

Molecular Basis of Host-Virus Interactions to Explain Relative Transmission and Severity Caused by Omicron and Delta variants of SARS-CoV-2

In India and other affected countries, Omicron variant of SARS-CoV-2 has shown faster transmission but less clinical severities when compared to Delta strain. Present study was aimed to investigate how molecular changes in the spike proteins of Omicron variant has increased its transmission but reduced the disease severity. We report molecular interactions of Spike proteins of Delta and Omicron variants with ACE-2 receptor to explain how change in chemical and physical nature of mutated amino acids of Omicron variant has affected the internalization competence of virus into host cell. The Research Collaboratory Structural Bioinformatics (RCSB) and Protein Data Bank (PDB) were used to construct ACE2-Spike Protein interaction. The binding affinity of both omicron and delta variant spike proteins with human ACE2 receptor was observed. Spike protein of Omicron variants has revealed total number of 93 dissimilarities of amino acids from Delta strain,15 of which are in its Receptor Binding Domain (RBD). Our study showed that RBD of Delta variant contained only one hydrophobic amino acid whereas there were 6 hydrophobic amino acids in the RBD of Omicron variant. We report that increased number of Hydrophobic Amino Acids in RBD of Omicron variant affects its binding with ACE2 receptor to enter into the cell. The failure of internalization of virus has increased concentration of extracellular virions at nasopharyngeal region leading to faster expulsion of infective droplets during coughing or sneezing to increase transmission but has reduced the severity of infection. The reported observations could prove to be of public health and therapeutic significance

Long Term Potentiation, Navigation & Dynamic Progamming Long Term Potentiation, Navigation & Dynamic Progamming

Abstract Blum and Abbott (1995) recently proposed an algorithm for learned navigation that is based on Hebbian changes to adaptive connections between place cells in the hippocampus. This paper suggests using a temporal difference rul

Smart power monitoring utility system using wireless sensor networks : a project report submitted in partial fulfilment of the requirements for the degree of Master of Engineering in Electronics and Electrical Engineering

The design and development of a Wireless Sensor Networks based Smart Grid for home utility system for power utility has been presented in this thesis. The system utilises wireless power monitoring devices and control units. The electronic wireless power monitoring devices have been designed to monitor electrical parameters such as voltage, current and power of the household appliances. The measured electrical parameters are transmitted to a central controller via the ZigBee node. The central coordinator has been configured around a laptop computer and receives all the transmitted data from different nodes. The computer stores the measured data and analyses them. The computer is also connected to internet and the website of the electrical power supply company is accessed. The real-time electricity tariff is available to the controller. Based on the tariff condition the controller can determine the off-peak and peak-electricity rate. The controller can decide to switch off the unimportant electrical loads at peak-tariff situation. This is implemented by sending the necessary command to the zigbee node connected to the appropriate load. The zigbee node can then switch off the load by sending an off-command to the triac which is used as the control device. The user has the options of controlling the electrical appliances in different modes. If the users would like to continue the load to be on during the peak-tariff condition, the option of a manual switch can be used to bypass the triac. The appropriate electrical loads can be monitored as well as controlled using the developed GUI available at the laptop. The complete information of the system is also available through a website and appropriate control action can be implemented through a secured access. The objective of the research is to lower the consumption of power during the peak-tariff condition and thereby saves electricity cost. A prototype has been designed, developed and extensively tested. This Thesis presents the current work, experimental results and concludes with possible future research opportunities

Conical whirl instability of hybrid porous journal bearings in laminar lubrication regime

131-137An analysis of conical whirl instability of an unloaded rigid rotor supported in hybrid porous oil journal bearings in laminar lubrication regime is presented here. The effect of bearing feeding parameter (β), aspect ratio (L/D), ratio of wall thickness to journal radius (H/R) and an isotropy of porous material on stability of rotor bearing system has been investigated. Higher values of β have been found to give better stability in conical whirl mode and higher stability is predicted if porous bush is considered to be isotropic

Internal cycling of dissolved barium in water column of the Bay of Bengal

Dissolved barium concentrations in water column of the Bay of Bengal along the 87°E transect (∼6°N to ∼21°N) have been measured to track the dispersion of its large influx from the Ganga–Brahmaputra river system and the outflow to the equatorial Indian Ocean. A typical barium concentration–depth profile shows relatively higher Ba concentrations in surface waters (depth ≤ 5 m) followed by a minimum in the depth interval ∼50–150 m and an increase at greater depth. The barium concentrations in surface waters (depth ≤ 5 m) of the Bay of Bengal vary from ∼35 nmol/kg at the southernmost station 0806 to ∼113 nmol/kg close to mouth of the Hooghly estuary (station 0816). The Ba data in upper layers (depth ≤ 100 m), excluding the very high Ba at station 0816, generally show a strong and significant inverse correlation with salinity (R² = 0.75; P < 0.0001). This indicates the southward flow of dissolved Ba from the Ganga–Brahmaputra river system that also includes its contributions by particle release and submarine groundwater discharge. The subsurface Ba minimum found in this study are ubiquitous and most probably a result of Ba uptake on settling particulates. On the other hand, the Ba concentrations in deep waters (depth > 500 m) is controlled dominantly by water mixing as suggested by a very strong and significant inverse correlation with salinity (R² > 0.95; P < 0.0001). Exceptions to this conservative behavior are the “hot-spots” of dissolved Ba in bottom waters, which are probably resulted by the dissolution of sediments at and/or below the sediment–water interface. Attempts were made to budget the Ba abundance in the Bay of Bengal using a two box model approach; surface (top ∼100 m) and deep waters (below ∼100 m). Under the steady state the annual Ba influx from the Ganga–Brahmaputra river system seems to be balanced through its removal via sinking particulates as a result there is no lateral outflow of dissolved Ba from the Ganga–Brahmaputra to the equatorial Indian Ocean through top ∼100 m of the Bay of Bengal. Most of this sinking particulate Ba (∼95%) is regenerated again in the lower box, preferentially in the intermediate waters ∼100–500 m. Therefore, frequently ventilated intermediate waters of the Bay of Bengal, receiving a large input of dissolved Ba through particle remineralization can be a significant source of dissolved Ba to the Indian Ocean

Behavior of dissolved redox sensitive elements (U, Mo and Re) in the water column of the Bay of Bengal

The dissolved concentrations of redox sensitive elements, U, Mo and Re have been measured in the water column of the Bay of Bengal (BoB) to track their distributions and behavior in its suboxic layers at the intermediate depths. The dissolved oxygen content in the intermediate waters (200–800 m) north of ∼11°N decreases to values as low as ∼3 μmol/ℓ. The distribution of U, Mo and Re in the surface waters along the 87°E transect shows a north–south gradient with significant correlation with salinity, underscoring the dominant influence of the Ganga–Brahmaputra (G–B) Rivers in controlling the geochemical budgets of these three elements. The concentrations of these three elements in surface and deep waters of the BoB are governed by salinity suggestive of their conservative behavior. On a macroscale, there is no discernable removal of U, Mo, or Re from the suboxic layer in the BoB water column, consistent with earlier studies in the suboxic zones of other oceanic regions. Further, their conservative behavior in the bay, suggest that the annual delivery of ∼109 tons of suspended matter rich in organic matter by G–B and other rivers do not have any measurable impact in determining their distributions. This study suggests that the suboxic conditions and high particulate flux prevailing in the water column of the Bay of Bengal do not affect the conservative behavior of U, Mo and Re. The dissolved Re concentrations in the upper layers in the central BoB seem to be marginally higher compared to that expected based on their salinities. This seems to be contributed from the Godavari River, which drains into the BoB and has dissolved Re three times higher than seawater. The higher Re concentrations in the central Bay of Bengal suggest that mixing process by local gyre and/or eddies in the BoB transports riverine dissolved material to ∼400 km offshore. More detailed transects of Re from the Godavari coast to central bay are needed to confirm this