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Multi-level clustering and Prediction based energy efficient routing protocol to eliminate Hotspot problem in Wireless Sensor Networks.
AbstractConserving energy of sensor nodes and ensuring balanced workloads among them are fundamental concerns in Wireless Sensor Network (WSN) design. Clustering strategies offer a promising avenue to minimize node energy consumption, thereby prolonging network lifespan. Nevertheless, numerous multi-hop routing protocols using clustering technique face the challenge of nodes nearer to the Base Station (BS) depleting their energy faster due to forwarding data from the entire network leading to premature node failure and network partitioning known as ‘hotspot problem’. The paper introduces an Energy-Efficient Mega-Cluster-Based Routing (EEMCR) protocol specially designed for expansive coverage area. The primary principle behind designing this protocol is to eliminate the hotspot problem and restrict the transmission range of nodes to the threshold distance defined by the radio energy model, thereby enhancing the overall network lifespan. The protocol adopts a centralized approach employing fixed clustering wherein the BS partitions the network into square-shaped clusters. The cluster size is determined by the threshold transmission range of the sensor radio energy model, guaranteeing that all network communication stays within this threshold distance. Four such clusters form a mega-cluster with a Mega-Cluster-Head (MCH) elected among the four Cluster Heads (CHs). The MCH role is evenly distributed among nodes of all four clusters in subsequent rounds for uniform distribution of its overhead. Implementing data aggregation at two levels (CH level as well as MCH level) leads to reduced data traffic and energy consumption throughout the network. Moreover, data collection by two data mules based on odd–even round number ensures balanced data traffic and energy distribution across the network. Analysis indicates that the proposed protocol effectively mitigates the hot-spot problem and reduces data transmission overhead of sensor nodes. In simulation, the proposed protocol on an average improves network life by 34.5%, 23.5%, 14.5% and 5.5% as compared to existing protocols FCEEC, DBSCAN, LPGCR and FBECS respectively for deployment of nodes between 600 to 1200. Also, approximately 46%, 32%, 21% and 14% of lesser sensor nodes are dead for proposed protocol in respective rounds as compared to existing protocols FCEEC, DBSCAN, LPGCR and FBECS respectively. Comparative evaluations demonstrate improved network lifetime when compared to equivalent recent routing protocols.
Stable antivortices in multiferroic ε-Fe2O3 with the coalescence of misaligned grains
AbstractAntivortices have potential applications in future nano-functional devices, yet the formation of isolated antivortices traditionally requires nanoscale dimensions and near-zero magnetocrystalline anisotropy, limiting their broader application. Here, we propose an approach to forming antivortices in multiferroic ε-Fe2O3 with the coalescence of misaligned grains. By leveraging misaligned crystal domains, the large magnetocrystalline anisotropy energy is counterbalanced, thereby stabilizing the ground state of the antivortex. This method overcomes the traditional difficulty of observing isolated antivortices in micron-sized samples. Stable isolated antivortices were observed in truncated triangular multiferroic ε-Fe2O3 polycrystals ranging from 2.9 to 16.7 µm. Furthermore, the unpredictability of the polarity of the core was utilized as a source of entropy for designing physically unclonable functions. Our findings expand the range of antivortex materials into the multiferroic perovskite oxides and provide a potential opportunity for ferroelectric polarization control of antivortices.
Agrivoltaics shading enhanced the microclimate, photosynthesis, growth and yields of vigna radiata genotypes in tropical Nigeria
Precisely designing asymmetrical selenium-based dual-atom sites for efficient oxygen reduction
Evolutionary game of international trade network based on trade policy differences
Exciton-polariton ring Josephson junction
Mechanistic insights into gut microbe derived siderophores and PHD2 interactions with implications for HIF-1α stabilization
Research on detection and treatment of loose zones in weak fracture zone tunnel
Evaluating the effectiveness of different intervention measures for an outbreak of mycoplasma pneumoniae in hangzhou based on a dynamic model
Novel insights into insect mediated polystyrene biodegradation through bacterial genome analyses
Abstract Plastic pollution is a significant environmental challenge of contemporary age. Polystyrene (PS), among the most commonly used plastic polymers worldwide, is highly durable and difficult to degrade. Despite various disposal strategies, PS continues to impact biodiversity, human health, and ecosystems. Recently, the scientific community has focused on the potential role of microorganisms for plastic biodegradation, particularly those from the gut of plastivorous insects. In a previous study, three bacterial strains, each representing a distinct taxonomic group (Klebsiella, Pseudomonas, and Stenotrophomonas), were isolated from Alphitobius diaperinus larvae after rearing on a PS diet and enriched in a medium with PS as the sole carbon source. The Stenotrophomonas sp. strain, here identified as S. indicatrix, showed the greatest potential for PS degradation. The present study investigates the genetic profile of the newly isolated S. indicatrix strain DAI2m/c through genome sequencing, to identify enzyme-encoding genes involved in the intracellular metabolic pathways responsible for the biodegradation of the styrene monomer. Our findings indicate that the genome of S. indicatrix strain DAI2m/c encodes all enzymes required for one of the two recognized styrene degradation pathways, suggesting its ability to convert styrene into byproducts that are then utilized for cellular energy production.
Improving the resilience of urban transportation to natural disasters: the case of Changchun, China
Modeling and dynamic analysis of split torsion transmission system considering backlash and center distance errors
Experimental study on steady-state operation of organic Rankine cycle system under different operating conditions
Insights into the photocatalytic removal of malachite green organic pollutant by highly efficient hard responsive Ba1 − xCoxDyyFe12−yO19 catalysts
Full-dimensional accurate potential energy surface and dynamics for the unimolecular isomerization reaction CH3NC ⇌ CH3CN
The reaction CH3NC ⇌ CH3CN, a model reaction for the study of unimolecular isomerization, is important in astronomy and atmospheric chemistry and has long been studied by numerous experiments and theories. In this work, we report the first full-dimensional accurate potential energy surface (PES) of this reaction by the permutation invariant polynomial-neural network method based on 30 974 points, whose energies are calculated at the CCSD(T)-F12a/AVTZ level. Then, ring polymer molecular dynamics is used to derive the free energy barrier of the reaction at the experimental temperature range of 472.55–532.92 K. Reaction kinetics are studied at the high-pressure limit and in the fall-off region by standard transition state theory and the master equation, respectively. The calculated temperature- and pressure-dependent rate coefficients are in good agreement with previous experimental and theoretical results. Furthermore, quasi-classical trajectory simulations are performed on this PES to study the intramolecular energy transfer dynamics at initial vibrational energies of 4.336, 5.204, and 6.505 eV.
Efficacy of home based computerized adaptive cognitive training in patients with post stroke cognitive impairment: a randomized controlled trial
TIP 4 P 2005 Ice : Simulating water with two molecular states
Rigid, non-polarizable water models are very efficient from a computational point of view, and some of them have a great ability in predicting experimental properties. There is, however, little room for improvement in simulating water with this strategy, whose main shortcoming is that water molecules do not change their interaction parameters in response to the local molecular landscape. In this work, we propose a novel modeling strategy that involves using two rigid non-polarizable models as states that water molecules can adopt depending on their molecular environment. During the simulation, molecules dynamically transition from one state to another depending on a local order parameter that quantifies some local structural feature. In particular, molecules belonging to low- and high-tetrahedral order environments are represented with the TIP4P/2005 and TIP4P/Ice rigid models, respectively. In this way, the interaction between water molecules is strengthened when they acquire a tetrahedral coordination, which can be viewed as an effective way of introducing polarization effects. We call the resulting model TIP4P2005Ice and show that it outperforms either of the rigid models that build it. This multi-state strategy only slows down simulations by a factor of 1.5 compared to using a standard non-polarizable model and holds great promise for improving simulations of water and aqueous solutions.
Impact of thermal denaturation on renal volume reduction after partial nephrectomy using soft coagulation hemostasis
Polariton spectra under the collective coupling regime. I. Efficient simulation of linear spectra and quantum dynamics
We outline two general theoretical techniques to simulate polariton quantum dynamics and optical spectra under the collective coupling regimes described by a Holstein–Tavis–Cummings (HTC) model Hamiltonian. The first one takes advantage of sparsity of the HTC Hamiltonian, which allows one to reduce the cost of acting polariton Hamiltonian onto a state vector to the linear order of the number of states, instead of the quadratic order. The second one is applying the well-known Chebyshev series expansion approach for quantum dynamics propagation and to simulate the polariton dynamics in the HTC system; this approach allows us to use a much larger time step for propagation and only requires a few recursive operations of the polariton Hamiltonian acting on state vectors. These two theoretical approaches are general and can be applied to any trajectory-based non-adiabatic quantum dynamics methods. We apply these two techniques with our previously developed Lindblad-partially linearized density matrix approach to simulate the linear absorption spectra of the HTC model system, with both inhomogeneous site energy disorders and dipolar orientational disorders. Our numerical results agree well with the previous analytic and numerical work.