A New Extensible Key Exchange Scheme For Wireless Sensor Networks

A sensor network is confident of a large number of sensor nodes Sensor nodes are small, low-cost, low-power devices that have following performance communicate on short distances sense environmental data perform limited data processing The network usually also contains “sink” node which connects it to the outside world. Advances in technology introduce new application areas for sensor networks. Foreseeable wide deployment of mission critical sensor networks creates concerns on security issues. Security of large scale slowly deployed and infrastructure-less wireless networks of resource limited sensor nodes requires efficient key distribution and management mechanisms. We consider distributed and hierarchical wireless sensor networks where unjust, multicast and broadcast type of communications can take place. We evaluate deterministic, probabilistic and hybrid type of key pre-distribution and dynamic key generation algorithms for distributing combination and network-wise keys

Dynamic hip screw technique in the management of trochanteric fracture

Background: Study was conducted to find the results of dynamic hip screw in the management of trochanteric fracture by analyzing the factors which influence post-operative mobility.Methods: Study was conducted in the department of orthopedics, GSL Medical College. Individuals >18 years, both genders who were diagnosed having trochanteric type I and II Boyd and Griffin stable fractures were included in the study. All surgeries were performed under spinal anesthesia, internal fixation with dynamic hip screw and 135o angled blade plate. Injectable third generation cephalosporins were used 24 hours preoperatively, intra- operatively and 5 days post-operatively, and oral antibiotics till suture removal. Patients allowed to sit on bed on 2nd and 3rd day and static quadriceps exercises were started from 2nd day onwards, hip and knee flexion exercises from 6 or 7th day and weight bearing walking form 10th day.Results: The average age was of the participants was 61.53 years, ranged between 41 to 80 years; 65% were female participants and 35% were male patients. In the study, 20 (50%) patients had right side fracture and left sided affection of trochanteric fracture to the remaining 50%. Most of the patients (67.5%) in this study were classified as type II Boyd and Griffin criteria, and 32.5% were type I. The clinical and functional outcome was calculated using the Kyle's criteria; 25% (10) showed excellent response, followed by good (50%), fair (15%) and poor (10%) results.Conclusions: Dynamic hip screw is the operative treatment of choice for stable trochanteric fractures. However, studies on large sample for long time are recommended

A Novel System for Scalable Data Sharing in Cloud Storage using Key-Aggregate

Of late, rapid growth observed in the cloud technology.  Data sharing is an essential functionality in cloud storage. In this paper, we show how to efficiently, securely and flexibly share data with others in cloud storage. We describe new public-key cryptosystems that produce constant-size ciphertexts such that efficient delegation of decryption rights for any set of ciphertexts is possible. The novelty is that one can aggregate any set of secret keys and make them as compact as a single key, but encompassing the power of all the keys being aggregated. In other words, the secret key holder can release a constant-size aggregate key for flexible choices of ciphertext set in cloud storage, but the other encrypted files outside the set remain confidential. This compact aggregate key can be conveniently sent to others or be stored in a smart card with very limited secure storage. We provide formal security analysis of our schemes in the standard model. We also describe other application of our schemes. In particular, our schemes give the first public-key patient-controlled encryption for flexible hierarchy, which was yet to be known

Thermal and Optoelectrical Analysis of La0.7Sr0.3MnO3 Thin Film Thermistor in 8-12 μm Range for Uncooled Microbolometer Application

La0.7Sr0.3MnO3 as a sensing material has shown an amazing potential for uncooled thermal imaging application. Here we report the fabrication of a La0.7Sr0.3MnO3 (LSMO) thin film thermistor on a Si wafer and explored two prime figure-of-merit such as temperature coefficient of resistance (TCR) and optical responsivity, which are very useful parameters to compare the performance with any thermal sensor. The LSMO films were deposited on a SrTiO3(STO) buffer layer with Si/SiO2 as a substrate, by a pulsed laser deposition (PLD) technique. The crystallinity and surface topography of the films were analyzed by X-ray diffraction (XRD) and atomic force microscopy (AFM). The fabricated device was then analyzed for its thermal and electrical characteristics to validate its suitability as an IR sensor. The fabricated device shows very sharp metal-to-insulator (TMI) phase transition temperature at 150 K and very high TCR of +4% K-1 and-4%K-1near 100 K and 200 K respectively, when the temperature was sweeped from 10 K to 300 K. Fabricated Thermistor shows very good thermal response and recovery when subjected to an alternating on-off cycle of IR lamp (150 W) illumination, which confirms its suitability for the highspeed thermal imaging application. The experimental analysis shows highest responsivity of ∼ 21085 V/W at 8.5 μm, which falls in the Long-Wave Infrared (LWIR) region, which is an ideal IR band for any thermal imaging application

An Implantable Bipolar Active Charge Balancing Circuit with Six Adjustment Current levels for Facial Paralysis Patients

Neural stimulation is a robust technique with fewer side effects that are used to cure several neurological diseases. The major issue in this neural stimulator is charge imbalances, caused due to device irregularities during fabrication. Generally, active charge balancing performs an almost accurate charge balance. However, the main disadvantages of these techniques are the additional power consumption for charge balancing, it only balances monopolar residual charge and uses fixed adjustment current with fixed or variable time. In this proposal, a novel implantable bipolar active charge balance circuit with a 6-level of adjustment currents is proposed. This circuit has the unique capability of separating the residual voltage into six levels, which covers the positive and negative residual voltage. By using this residual voltage partition, if the residual voltage crosses the safety limits (either positive or negative), it is balanced with equivalent opposite current without unnecessary charge accumulation. The proposed calibration circuit is designed on CMOS 180nm technology and consumes around 26μW. It also maintains the power ratio of the calibration circuit to the stimulation circuit between 1 and 1.8 percent. © 2021 IEEE

A Hybrid Bipolar Active Charge Balancing Technique with Adaptive Electrode Tissue Interface (ETI) Impedance Variations for Facial Paralysis Patients

Functional electrical stimulation (FES) is a safe, effective, and general approach for treating various neurological disorders. However, in the case of FES usage for implantable applications, charge balancing is a significant challenge due to variations in the fabrication process and electrode tissue interface (ETI) impedance. In general, an active charge balancing approach is being used for this purpose, which has limitations of additional power consumption for residual voltage calibration and undesired neurological responses. To overcome these limitations, this paper presents a reconfigurable calibration circuit to address both ETI variations and charge balancing issues. This reconfigurable calibration circuit works in two modes: An impedance measurement mode (IMM) for treating ETI variations and a hybrid charge balancing mode (HCBM) for handling charge balance issues. The IMM predicts the desired stimulation currents by measuring the ETI. The HCBM is a hybrid combination of electrode shorting, offset regulation, and pulse modulation that takes the best features of each of these techniques and applies them in appropriate situations. From the results, it is proved that the proposed IMM configuration and HCBM configuration have an optimal power consumption of less than 44 µW with a power ratio ranging from 1.74 to 5.5 percent when compared to conventional approaches. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

An Automated Algorithm for Blood Vessel Count and Area Measurement in 2-D Choroidal Scan Images

We present an automated algorithm for the detection of blood vessels in 2-D choroidal scan images followed by a measurement of the area of the vessels. The objective is to identify vessel parameters in the choroidal stroma that are affected by various abnormalities. The algorithm is divided into five stages. In the first stage, the image is denoised to remove sensor noise and facilitate further processing. In the second stage, the image is segmented in order to find the region of interest. In the third stage, three different contour detection methods are applied to address different challenges in vessel contour. In the fourth stage, the outputs of the three contour detection methods are combined to achieve refined vessel contour detection. In the fifth and final stage, the area of these contours are measured. The results have been evaluated by a practicing opthalmologist and performance of the algorithm relative to expert detection is reporte