Summary
The Internet of Things (IoT) is a system that includes smart items with different sensors, advanced technologies, analytics, cloud servers, and other wireless devices that integrate and work ...together to create an intelligent environment that benefits end users. With its wide spectrum of applications, IoT is revolutionizing both the current and future generations of the Internet. IoT systems can be employed for broad‐ranging real applications, such as agriculture, the environment, cities, healthcare, and the industrial sector. In this paper, we briefly discuss the three‐tier architectural view of IoT, its different communication technologies, and the smart sensors. Moreover, we study various application areas of IoT such as the environmental domain, healthcare, agriculture, smart cities, and industrial, commercial, and general aspects. A critical analysis is shown for the existing schemes and techniques related to this work. Further, this paper addresses the basic context, tools and evaluation approaches, future scope, and the advantages and disadvantages of the aforestated IoT applications. A comprehensive analysis is provided for each domain along with its fundamental parameters like the quality of service (QoS), network longevity, scalability, energy efficiency, accuracy, and cost. Finally, this study highlights the technical challenges and open research problems existing in different IoT applications.
At present scenario, Unmanned Aerial Vehicles (UAVs) have been growing in popularity exploiting high mobility, easily deployability and low cost. Sometimes, at remote agricultural sites it become ...impossible for humans to operate all the time. At such agriculture sites, UAVs can be deployed easily. Planning a path for UAV trajectory is also very difficult task as it involves calculation of infinite number of points. In this article, we have proposed a projectile trajectory for UAV to Ground Terminal (GT) communication without obstacles in between for crop monitoring. Line of site (LoS) and path-loss scenarios are taken into account for UAV-GT communication. For solving higher order integration problem, we have used Simpson's rule for calculating transmission rate and is maximized between angle of projections 15° and 30° using Genetic Algorithm (GA). It is also observed that gravity plays a major role in the proposed trajectory. Also, energy is a powerful resource and UAV as small in size lacks this resource and must be saved for following trajectory path in fixed time. Therefore, with the help of GA, we have minimized energy for the proposed trajectory.
Previously synthesized novel chalcone oxime ethers (COEs) were evaluated for inhibitory activities against monoamine oxidases (MAOs) and acetylcholinesterase (AChE). Twenty-two of the 24 COEs ...synthesized, except
and
, had potent and/or significant selective inhibitory effects on MAO-B.
potently inhibited MAO-B with an IC
value of 0.018 µM, which was 105, 2.3, and 1.1 times more potent than clorgyline, lazabemide, and pargyline (reference drugs), respectively.
, and
were also active against MAO-B, both had an IC
value of 0.028 µM, which was 67 and 1.5 times lower than those of clorgyline and lazabemide, respectively. Most of the COEs exhibited weak inhibitory effects on MAO-A and AChE.
most potently inhibited MAO-A (IC
= 0.88 µM) and also significantly inhibited MAO-B (IC
= 0.13 µM), and it could be considered as a potential nonselective MAO inhibitor.
and
inhibited AChE with IC
values of 5.35 and 4.39 µM, respectively. The selectivity index (SI) of
for MAO-B was higher than that of
(SI = 778.6 vs. 222.2), but the IC
value (0.028 µM) was slightly lower than that of
(0.018 µM). In reversibility experiments, inhibitions of MAO-B by
and
were recovered to the levels of reference reversible inhibitors and both competitively inhibited MAO-B, with K
values of 0.0075 and 0.010 µM, respectively. Our results show that
and
are potent, selective MAO-B inhibitors, and
is a candidate of dual-targeting molecule for MAO-B and AChE.
Wireless Underground Sensor Networks (WUSN) are gaining popularity due to their usage in vast prospective domains. Despite wide potential applications, many research issues in WUSNs need to be dealt ...with. Coverage Holes in WUSNs are one of the major issues that need attention. Nature-inspired optimization algorithms play a crucial role in modern computing, and for more than three decades, the field has made tremendous progress. Traditional algorithms are being replaced with these and have proved their competitiveness in various domains. In this paper, we have proposed an intelligent optimization algorithm based on the TSA (Tree Seed Algorithm) for patching the holes in the network and deciding on effective patching positions such that it reduces the maximum number of holes in the network. The proposed algorithm makes use of random, best, and spiral tree generation for getting the best optimal locations of sensor nodes to be deployed for healing the target region. First, an energy-efficient deterministic algorithm is applied for hole identification in the network. Then, an optimization-based nature-inspired algorithm is applied to heal the holes. The proposed algorithms and others are simulated through MATLAB and results are computed for the randomly deployed network. The proposed hole healing algorithm MTSA (modified TSA) has been compared with PSO (Particle Swarm Optimization) and TSA algorithms. Simulation results prove the effectiveness and robustness of the proposed algorithm. The proposed hole healing algorithm is suitable for small to large-size networks and reduces the larger number of holes than PSO and the original TSA algorithm.
Wireless underground sensor networks (WUSNs) are being used in agricultural applications, in border patrol, and in the monitoring of remote areas. Coverage holes in WUSNs are an issue which needs to ...be dealt with. Coverage holes may occur due to random deployment of nodes as well as the failure of nodes with time. In this paper, a mathematical approach for hole detection using Delaunay geometry is proposed which divides the network region into Delaunay triangles and applies the laws of triangles to identify coverage holes. WUSNs comprise static nodes, and replacing underground nodes is a complex task. A simplistic algorithm for detecting coverage holes in static WSNs/WUSNs is proposed. The algorithm was simulated in the region of interest for the initially randomly deployed network and after energy depletion of the nodes with time. The performance of the algorithm was evaluated by varying the number of nodes and the sensing radius of the nodes. Our scheme is advantageous over other schemes in the following aspects: (1) it builds a mathematical model and polynomial-time algorithm for detecting holes, and (2) the scheme does not work on centralized computation and therefore provides better scalability, (3) is energy-efficient, and (4) provides a cost-effective solution to detect holes with great accuracy and a low detection time. The algorithm takes less than 0.1 milliseconds to detect holes in a 100 m × 100 m-size network with 100 sensor nodes having a sensing radius of 8 m. The detection time shows only a linear change with an increase in the number of nodes in the network, which makes the algorithm applicable for every network size from small to large.
The problem of spectrum scarcity is an important issue in the field of cognitive radio ad-hoc networks. This problem attributes to the fact that spectrum usage must be efficient, today. In this ...paper, a Modified-Packet Reservation Multiple Access Protocol is proposed for decentralized cognitive radio ad-hoc networks by making the use Opportunistic/Overlay Spectrum Access method for share spectrum with primary users (PU) to cope with the problem of spectrum scarcity and inefficient spectrum utilization. The Secondary Users can use the unused time slots assigned to PU. The protocol designed in this paper is a combination of slotted-ALOHA and CSMA/CA protocol. In order to analyse the model mathematically and derive out the throughput, a four state Markov Chain model is defined in the given paper. The performance evaluation of the discussed protocol is done in terms of the throughput with a number of varying parameters like number of slots, number of packets transmitted by Secondary Users etc. At the end, significant results with discussion are presented in the form graphs in accordance with a number of stated parameters.
Cropland suitability assessment is an essential technique for agricultural development and future planning. It is an evaluation to determine how suitable the land is for growing a specific crop in a ...particular region based on multiple parameters like soil, climate, topography, socio-economic condition, infrastructure, irrigation, existing land use/land cover and environmental aspects. The paper presents different multi-criteria evaluation (MCE) techniques such as Analytical Hierarchy Process (AHP), Fuzzy Analytical Hierarchy Process (FAHP), Analytic Network Process (ANP), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and ELimination Et Choice Translating REality (ELECTRE) approaches integrated with geospatial technology, namely remote sensing and Geographical Information System for cropland suitability assessment. Review findings indicate that the AHP technique was used by53% of the researchers, followed by FAHP (16%); ANP (6%); TOPSIS (6%); ELECTRE (3%) and other techniques (16%) with or without geospatial technology. The integrated approach of MCE with geospatial was used by 69%, among which AHP technique of MCE was used by 72%; whereas, 22% used geospatial and 9% used MCE techniques alone. The results from the selected research articles also indicated that the most important input parameters were soil, topography and climate used by 97%, 88% and 74% of the researchers, respectively. The review can be helpful for researchers and decision-makers to select the most robust methods and standard parameters required for cropland suitability assessment to achieve higher agricultural production on a sustained basis.
An efficient protocol for Pd-catalyzed 2,2,2-trifluoroethoxylation of activated aryl bromides and bromo-chalcones has been developed. We unveil a fascinating insight into the Pd-catalyzed C–O ...cross-coupling reaction. Pd/tBuXPhos (L1) ligand system facilitates the C–O cross-coupling reaction between 2,2,2-trifluoroethanol and activated aryl bromides at both higher (115 °C) and lower temperatures (40 °C). Unprecedentedly, this catalyst system facilitates the C–O cross-coupling reaction in short span of reaction times, generally 5–25 min (at 115 °C). The structurally simple analogue of tBuXPhos ligand so called JohnPhos (L2) ligand is also facilitated the C–O bond formation with activated aryl bromides and bromo-chalcones. Interestingly, under the optimal conditions (L1), methanol is also coupled rapidly with activated aryl bromides. These catalyst systems (L1 and L2) fail to couple electron rich aryl bromides with 2,2,2-trifluoroethanol, thus these catalyst systems allow the reductive elimination through an electronic pathway of reductive elimination. The unusual reactivity of 2,2,2-trifluoroethanol in Pd-catalyzed C–O cross-coupling reaction makes that the chemistry of fluorinated molecules is unique than that of non-fluorinated analogues. The bromo-chalcones can be used as a new coupling partner in the cross-coupling reaction.
Display omitted An efficient Pd-catalyzed C–O bond forming reaction between bromo-chalcones and 2,2,2-trifluoroethanol has been reported. Bromo-chalcones could be used as a new coupling partner in the cross-coupling reaction. Pd/L1 catalyst system could couple the 2,2,2-trifluoroethanol and methanol with activated aryl bromides in short reaction times, generally 5–25 min.
The coverage and connectivity are the two imperative performance metrics for the growth of wireless sensor networks (WSNs) with sprouting technologies. In order to maintain these metrics, the issue ...of finding and healing of coverage hole is closely related to these two facts and plays a vital role in the performance improvement of the network. Many works in the past explored for 2D-WSNs, but now the time has come to investigate this matter for 3D-WSNs to reach the new heights of research and technology. In this paper, different scenarios with respect to the deployment of sensor nodes or network topology with the presence of different shaped coverage holes are discussed. Not only this, to heal these perceived holes introduction of sensor nodes having sensing radius different from initial deployed sensors has been suggested which in turn outlines the development of heterogeneous sensor networks, a keen issue with respect to technology development. This deployment of sensors to constitute heterogeneous sensor networks also influences the overall network cost in terms of cost reduction with an optimum coverage level. A mathematical analysis to give a relationship between the radii of former and later deployed sensor nodes is presented in the form of theorem. At the end, the results and discussion in order to achieve a specified level of coverage with respect to different packing patterns based on the mathematical analysis are provided. Also, some future directions to guide the researchers are discussed in this paper.
We report an unprecedented BrettPhos ligand supported Pd‐catalyzed CO bond‐forming reaction of activated aryl halides with primary fluoroalkyl alcohols. We demonstrate that the Phosphine ligand ...(BrettPhos) possesses the property of altering the mechanistic pathway of reductive elimination from nucleophile to nucleophile. The Pd/BrettPhos catalyst system facilitates the reductive elimination of the oxygen nucleophile through an electronic pathway.
CO coupling: A BrettPhos ligand supported Pd‐catalyzed CO bond‐forming reaction of activated aryl halides with primary fluoroalkyl alcohols is reported. BrettPhos ligand (L1) can alter the mechanistic pathway of reductive elimination from nucleophile to nucleophile (see scheme; Rf=–(CF2)nCF3; R=electron‐releasing groups (ERGs) at o‐, m‐ and p‐positions, neutral, and electron‐withdrawing groups at o‐ and m‐positions; EWG=electron‐withdrawing group).
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