1,931 research outputs found
Distributed Optimization in Energy Harvesting Sensor Networks with Dynamic In-network Data Processing
Energy Harvesting Wireless Sensor Networks (EH- WSNs) have been attracting increasing interest in recent years. Most current EH-WSN approaches focus on sensing and net- working algorithm design, and therefore only consider the energy consumed by sensors and wireless transceivers for sensing and data transmissions respectively. In this paper, we incorporate CPU-intensive edge operations that constitute in-network data processing (e.g. data aggregation/fusion/compression) with sens- ing and networking; to jointly optimize their performance, while ensuring sustainable network operation (i.e. no sensor node runs out of energy). Based on realistic energy and network models, we formulate a stochastic optimization problem, and propose a lightweight on-line algorithm, namely Recycling Wasted Energy (RWE), to solve it. Through rigorous theoretical analysis, we prove that RWE achieves asymptotical optimality, bounded data queue size, and sustainable network operation. We implement RWE on a popular IoT operating system, Contiki OS, and eval- uate its performance using both real-world experiments based on the FIT IoT-LAB testbed, and extensive trace-driven simulations using Cooja. The evaluation results verify our theoretical analysis, and demonstrate that RWE can recycle more than 90% wasted energy caused by battery overflow, and achieve around 300% network utility gain in practical EH-WSNs
Infinite integral conditions for oscilation of first order linear delay differential equations with positive and negative coefficients
This study obtains a new set of integral conditions for oscillation of nonautonomous delay differential equations with positive and negative coefficients. It is however, discovered that every solution of the equation oscillates infinitely.Keywords: Integral Condition, Oscillation, Positive and Negative Coefficient
Theory of Weiss oscillations in the magnetoplasmon spectrum of Dirac electrons in graphene
We present the collective excitations spectrum (magnetoplasmon spectrum) of
Dirac electrons in a weakly modulated single graphene layer in the presence
of a uniform magnetic field. We consider electric modulation in one-dimension
and the magnetic field applied perpendicular to graphene.We derive analytical
results for the intra-Landau band plasmon spectrum within the
self-consistent-field approach. We find Weiss oscillations in the
magnetoplasmon spectrum which is the primary focus of this work. Results are
presented for the intra-Landau band magnetoplasmon spectrum as a function of
inverse magnetic field. These results are also compared with those of
conventional 2DEG. We have found that the Weiss oscillations in the
magnetoplasmon spectrum are larger in amplitude compared to those in
conventional 2DEG for the same modulation strength, period of modulation and
electron density.Comment: 9 pages, 1 figure Phys. Rev. B (accepted for publication
Uji Performansi Desain Terintegrasi Tungku Biomassa dan Penukar Panas
Serangkaian pengujian terhadap desain terintegrasi tungku biomassa dan penukar panas telah dilakukan untuk melihat performansinya menggunakan metode efektifitas-NTU (e-NTU), efisiensi sebagai fungsi dari fin analogy number (h(Fa)) dan beda temperatur rata-rata logaritmik (LMTD). Tungku biomassa sebagai pembangkit panas menghasilkan energi senilai 25.600W dengan laju pembakaran tongkol jagung 7.03 kg/jam. Perhitungan laju pindah panas ke fluida dingin dalam pipa sebagai fungsi dari karakteristik udara, laju massa melalui luas penampang laluan diperoleh sebesar 11,285W. Efektivitas sebagai rasio laju pindah panas aktual dengan panas maksimum yang dapat dipindahkan dalam sebuah penukar panas diperoleh sebesar 0,90. Efisiensi penukar panas sebagai ukuran jelas performansi sistem diperoleh sebesar 0,78. Efisiensi dalam hal ini adalah fungsi dari fin analogy number sedangkan fin analogy number merupakan fungsi dari beberapa variabel seperti hasil perkalian UA, laju kapasitas panas minimum (Cmin) dan rasio kapasitas (Cr). Performansi lainnya ditunjukkan melalui nilai faktor koreksi sebesar 0,5 menunjukkan bahwa penukar panas tidak sepenuhnya merupakan aliran-melawan melainkan terbentuk aliran-silang khususnya di dalam ruang antar sekat dengan pola turbulensi (Re: 8.524 > 6.000)
Sequence comparison and phylogenetic analysis of core gene of hepatitis C virus from Pakistani population
In Pakistan, more than 10 million people are living with hepatitis C virus (HCV) with high morbidity and mortality. The aims of the present study are to report HCV core gene sequences from Pakistani population and perform their sequence comparison/phylogenetic analysis. The core gene of HCV has been cloned from six different patients and sequences submitted at the National Center of Biotechnology Information (NCBI). Nucleotides and deduced amino acid sequence comparison of six isolates was performed with each other and with two HCV genotype 3a type examples reported from Japan. Phylogenetic tree of HCV core sequences was constructed using CLC software. Nucleotides sequence comparison showed that our sequences have 94 to 96% homology with NZL1 strain and 90 to 93%homology with HCV-K3A/650 strain. Deduced amino acid sequence comparison showed that our sequences have 92 to 98% homology with NZL1 strain and 88 to 94% homology with HCV-K3A/650 strain.Phylogenetic analysis suggests that our sequences are clustered with sequences reported from Japan. This is the first phylogenetic analysis of HCV core gene from Pakistani population. Our sequences and sequences from Japan are grouped into same cluster in the phylogenetic tree. Sequence comparison and phylogenetic analysis showed that our isolates have high homology with Japanese isolates
Ferromagnetic Enhancement of CE-type Spin Ordering in (Pr,Ca)MnO
We present resonant soft X-ray scattering (RSXS) results from small band
width manganites (Pr,Ca)MnO, which show that the CE-type spin ordering (SO)
at the phase boundary is stabilized only below the canted antiferromagnetic
transition temperature and enhanced by ferromagnetism in the macroscopically
insulating state (FM-I). Our results reveal the fragility of the CE-type
ordering that underpins the colossal magnetoresistance (CMR) effect in this
system, as well as an unexpected cooperative interplay between FM-I and CE-type
SO which is in contrast to the competitive interplay between the ferromagnetic
metallic (FM-M) state and CE-type ordering.Comment: Accepted for publication in Phys. Rev. Let
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