Connectivity preserving localized coverage algorithm for area monitoring using wireless sensor networks

Efficient network coverage and connectivity are the requisites for most Wireless Sensor Network (WSN) deployments, particularly those concerned with area monitoring. Due to the resource constraints of the sensor nodes, redundancy of coverage area must be reduced for effective utilization of the available resources. If two nodes have the same coverage area in their active state, and if both the nodes are activated simultaneously, it leads to redundancy in network and wastage of precious sensor resources. In this paper, we address the problem of network coverage and connectivity and propose an efficient solution to maintain coverage, while preserving the connectivity of the network. The proposed solution aims to cover the area of interest (AOI), while minimizing the count of the active sensor nodes. The overlap region of two sensor nodes varies with the distance between the nodes. If the distance between two sensor nodes is maximized, the overall coverage area of these nodes will also be maximized. Also, to preserve the connectivity of the network, each sensor node must be in the communication range of at least one other node. Results of simulation of the proposed solution indicate up to 95% coverage of the area, while consuming very less energy of 9.44 J per unit time in the network, simulated in an area of 2500 m².     

A more efficient and secure ID-based remote mutual authentication with key agreement scheme for mobile devices on elliptic curve cryptosystem

Recently, Yang and Chang proposed an identity-based remote login scheme using elliptic curve cryptography for the users of mobile devices. We have analyzed the security aspects of the Yang and Chang's scheme and identified some security flaws. Also two improvements of the Yang and Chang's scheme have been proposed recently, however, it has been found that the schemes have similar security flaws as in the Yang and Chang's scheme. In order to remove the security pitfalls of the Yang and Chang and the subsequent schemes, we proposed an enhanced remote user mutual authentication scheme that uses elliptic curve cryptography and identity-based cryptosystem with three-way challenge-response handshake technique. It supports flawless mutual authentication of participants, agreement of session key and the leaked key revocation capability. In addition, the proposed scheme possesses low power consumption, low computation cost and better security attributes. As a result, the proposed scheme seems to be more practical and suitable for mobile users for secure Internet banking, online shopping, online voting, etc.     

Obtaining a durable power of attorney for health care from nursing home residents

BACKGROUND: A durable power of attorney for health care (DPA) allows a person to appoint a surrogate decision-maker for any future period of mental incapacity. The absence of advance directives can lead to confusion and the expenditure of resources while trying to exert a substituted judgment. METHODS: The Wisconsin DPA was presented with an organized pilot program to 150 residents who had been judged by their social workers to have the capacity to make informed decisions regarding medical care. The reasons residents gave for accepting or rejecting a DPA were analyzed. RESULTS: Seventy-nine percent prepared a DPA. Reasons for signing included allowing the resident to decide who would make medical decisions and assuring that specific wishes would be carried out. Twenty-one percent did not execute a DPA. Reasons were categorized as confusion and misunderstanding regarding the legal system, mistrust, or social isolation. CONCLUSIONS: The high rate (79%) of DPA completion is probably related to individually counseling residents. However, competent residents who despite counseling do not choose to execute a DPA can have detailed advance directives ("living wills") prepared without appointing a decision-maker.     

Influence of dietary iron deficiency on acute metal intoxication

The frequent difficulties encountered in the diagnosis of pediatric sarcomas, caused by the lack of observable differentiation at the light microscopic level, has led to the routine use of immunohistochemistry in pediatric surgical pathology. To a large degree the advent of this staining technique has led to the correct assessment of many perplexing lesions that previously would have been given inconclusive diagnoses. However, with increased usage and testing, it has become apparent that there are few, if any, "magic bullets" in immunohistochemistry for pediatric pathologists. Thus, it behooves diagnosticians to be careful in the usage of this technique, to be aware of possible discrepancies in its results, and to remember the ancillary nature of its application. The following article will review selected markers commonly used in pediatric surgical pathology, from both previous reports and the author's perspective, and will briefly consider several new phenotypic markers which have potential utility with childhood sarcomas.     

Semiconduction properties of some polyene-iodine charge-transfer complexes and their application in solid-state batteries

The conjugated polyenes -carotene, lutein, retinoic acid and -apo-8-carotenal are shown to form charge-transfer (CT) complexes with the electron acceptor iodine. The conductivity increases by several orders of magnitude and the activation energy decreases on CT complex formation. Using these complexes as cathodic material, batteries with the configuration Mg/(polyene-iodine CT complex) /graphite are developed. Different battery parameters are evaluated. The effects of ambient temperature and humidity on battery performance are also studied. Results show that a -apo-8-carotenal-l₂ based battery has the maximum power density and longest self-life and is suitable for use as a micro-electronic gadget energizer.     

A learning automata-based fault-tolerant routing algorithm for mobile ad hoc networks

Reliable routing of packets in a Mobile Ad Hoc Network (MANET) has always been a major concern. The open medium and the susceptibility of the nodes of being fault-prone make the design of protocols for these networks a challenging task. The faults in these networks, which occur either due to the failure of nodes or due to reorganization, can eventuate to packet loss. Such losses degrade the performance of the routing protocols running on them. In this paper, we propose a routing algorithm, named as learning automata based fault-tolerant routing algorithm (LAFTRA), which is capable of routing in the presence of faulty nodes in MANETs using multipath routing. We have used the theory of Learning Automata (LA) for optimizing the selection of paths, reducing the overhead in the network, and for learning about the faulty nodes present in the network. The proposed algorithm can be juxtaposed to any existing routing protocol in a MANET. The results of simulation of our protocol using network simulator 2 (ns-2) shows the increase in packet delivery ratio and decrease in overhead compared to the existing protocols. The proposed protocol gains an edge over FTAR, E2FT by nearly 2% and by more than 10% when compared with AODV in terms of packet delivery ratio with nearly 30% faulty nodes in the network. The overhead generated by our protocol is lesser by 1% as compared to FTAR and by nearly 17% as compared to E2FT when there are nearly 30% faulty nodes.     

Minimal pathset and minimal cutsets using search technique

Application of graph theory to reliability analysis was first made in 1970 ^[1]. Over the years, a large number of computer programmes have been developed to determine the spanning trees, the minimal paths and cutsets, which are essential for determining the reliability of the network. In recent years, there has been an interest 2., 4. in developing small desk top calculators for specific purposes, which could be used by the designers of transportation systems, communication systems, etc. In this article the authors present an approach to design a microprocessor based equipment to determine minimal pathset and minimal cutset from the incidence matrix of the graph. The authors have presented a new design approach, based on search technique. The salient feature of the new approach is a novel tracing process in which the desired graph is traced by operating a set of constraints. The new design approach has already been used by the authors to develop a microprocessor based spanning tree generator 2., 3..     

Creatine kinase isoenzymes in serum from cord blood and the blood of healthy full-term infants during the first three postnatal days

Isoenzymes of creatine kinase (ATP:creatine phosphotransferase; EC 2.7.3.2; CK) were measured by electrophoresis in serum from cord blood and skin-puncture blood taken from 45 healthy full-term infants during the first three postnatal days. Mean total CK activities (in U/L at 30 degrees C) were 185 in cord samples, 536 in samples taken between 5--8 h postnatally, 494 between 24--33 h, and 288 in the 72-100 h samples. Values for all three isoenzymes increased to a peak over this period, with the highest values generally being found in the samples taken 5--33 h after birth; the subsequent decline was most rapid for CK-BB. Serum CK isoenzymes in cord samples and those taken at 72--100 h in the 11 babies delivered by cesarian section did not differ significantly from those of babies delivered vaginally. However the postnatal increases in total CK, CK-MM, and CK-MB (but not in CK-BB) were significantly greater in those patients born by vaginal delivery. The reasons for the increases in CK isoenzymes after birth are not clear, but our results and reported studies on the ontogeny of CK suggest that CK-MB cannot be regarded as a "cardiac-specific" isoenzyme in the neonatal period.     

Effect of thiourea during nickel electrodeposition from acidic sulfate solutions

The effect of thiourea on the cathodic current efficiency (CE), deposit quality, crystallographic orientations, surface morphology, and polarization behavior of the cathode was investigated during nickel electrodeposition from acidic sulfate solutions for 2 hours at 60 °C. A slight decrease of 3 to 4 pct in the CE was observed, when the concentration of thiourea was increased from 2 to 40 mg dm⁻³. The nickel deposit quality deteriorated significantly at higher thiourea concentrations; the surface morphology deteriorated and the contamination of the nickel deposits increased. The presence of thiourea affected the peak intensities of the crystal planes. Cyclic voltammetric studies on nickel deposition at 25 °C revealed depolarization behavior of the cathode at lower thiourea concentrations, ≤10 mg dm⁻³; however, a mixed behavior is observed at higher thiourea concentrations. These changes were also observed in the exchange current density (i ₀) values.     

Morphology,Mineralogy and Mixing of Individual Atmospheric Particles Over Kanpur (IGP): Relevance of Homogeneous Equivalent Sphere Approximation in Radiative Models

Estimation of the direct radiative forcing (DRF) by atmospheric particles is uncertain to a large extent owing to uncertainties in their morphology (shape and size), mixing states, and chemical composition. A region-specific database of the aforementioned physico-chemical properties (at individual particle level) is necessary to improve numerically-estimated optical and radiative properties. Till date, there is no detailed observation of the above mentioned properties over Kanpur in the Indo-Gangetic Plain (IGP). To fill this gap, an experiment was carried out at Kanpur (IITK; 26.52°N, 80.23°E, 142 m msl), India from April to July, 2011. Particle types broadly classified as (a) Cu-rich particles mixed with carbon and sulphur (b) dust and clays mixed with carbonaceous species (c) Fe-rich particles mixed with carbon and sulfur and (d) calcite (CaCO₃) particles aged with nitrate, were observed. The frequency distributions of aspect ratio (AR; indicator of extent of particle non-sphericity) of total 708 particles from April to June reveal that particles with aspect ratio range >1.2 to ≤1.4 were abundant throughout the experiment except during June when it was found to shift to high AR range, >1.4 to ≤1.6 (followed with another peak of AR i.e. >2 to ≤2.4) due to dust storm conditions enhancing the occurrence of more non-spherical particles over the sampling site. The spherical particles (and close to spherical shape; AR range, 1.0 to ≤1.2) were found to be <20% throughout the experiment with a minimum (11.5%) during June. Consideration of Homogeneous Equivalent Sphere Approximation (HESA) in the optical/radiative model over the study region is found to be irrelevant during the campaign.