1,626 research outputs found
Electricity consumption forecasting using Adaptive Neuro-Fuzzy Inference System (ANFIS)
Universiti Tun Hussein Onn Malaysia (UTHM) is a developing Malaysian Technical University. There is a great development of UTHM since its formation in 1993. Therefore, it is crucial to have accurate future electricity consumption forecasting for its future energy management and saving. Even though there are previous works of electricity consumption forecasting using Adaptive Neuro-Fuzzy Inference System (ANFIS), but most of their data are multivariate data. In this study, we have only univariate data of UTHM electricity consumption from January 2009 to December 2018 and wish to forecast 2019 consumption. The univariate data was converted to multivariate and ANFIS was chosen as it carries both advantages of Artificial Neural Network (ANN) and Fuzzy Inference System (FIS). ANFIS yields the MAPE between actual and predicted electricity consumption of 0.4002% which is relatively low if compared to previous works of UTHM electricity forecasting using time series model (11.14%), and first-order fuzzy time series (5.74%), and multiple linear regression (10.62%)
Unidirectional and wavelength-selective photonic sphere-array nanoantennas
We design a photonic sphere-array nanoantenna (NA) exhibiting both strong directionality and wavelength selectivity. Although the geometric configuration of the photonic NA resembles a plasmonic Yagi-Uda NA, it has different working principles and, most importantly, reduces the inherent metallic loss from plasmonic elements. For any selected optical wavelength, a sharp Fano resonance by the reflector is tunable to overlap spectrally with a wider dipole resonance by the sphere-chain director, leading to high directionality. This Letter provides design principles for directional and selective photonic NAs, which are particularly useful for photon detection and spontaneous emission manipulation. © 2012 Optical Society of America.published_or_final_versio
Enhanced ferroelectric and piezoelectric properties in doped lead-free (Bi0.5Na0.5)0.94Ba0.06TiO3 thin films
Doping effects with respect to the electrical properties of morphotropic phase boundary Bi0.5Na0.50.94Ba0.06TiO3 thin films epitaxially grown on CaRuO3 electroded LaAlO30.3Sr2AlTaO60.35 (001) substrates were investigated. Substantial enhancement of ferroelectricity and piezoelectricity has been achieved in La+Ce codoped films with a remanent polarization Pr of 29.5 C/cm2 and a remanent piezoelectric coefficient d33f of 31 pm/V, whereas Mn doping seems more favorite to reduce the leakage current by two order of magnitude. Both doped films exhibited diodelike I-V characteristics, which are correlated with resistance switching effect
Mechanical properties related to the relaxor-ferroelectric phase transition of titanium-doped lead magnesium niobate
2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
TEDD: a database of temporal gene expression patterns during multiple developmental periods in human and model organisms
Characterization of the specific expression and chromatin profiles of genes enables understanding how they contribute to tissue/organ development and the mechanisms leading to diseases. Whilst the number of single-cell sequencing studies is increasing dramatically; however, data mining and reanalysis remains challenging. Herein, we systematically curated the up-to-date and most comprehensive datasets of sequencing data originating from 2760 bulk samples and over 5.1 million single-cells from multiple developmental periods from humans and multiple model organisms. With unified and systematic analysis, we profiled the gene expression and chromatin accessibility among 481 cell-types, 79 tissue-types and 92 timepoints, and pinpointed cells with the co-expression of target genes. We also enabled the detection of gene(s) with a temporal and cell-type specific expression profile that is similar to or distinct from that of a target gene. Additionally, we illustrated the potential upstream and downstream gene−gene regulation interactions, particularly under the same biological process(es) or KEGG pathway(s). Thus, TEDD (Temporal Expression during Development Database), a value-added database with a user-friendly interface, not only enables researchers to identify cell-type/tissue-type specific and temporal gene expression and chromatin profiles but also facilitates the association of genes with undefined biological functions in development and diseases. The database URL is https://TEDD.obg.cuhk.edu.hk/
Spontaneous Emission in 2D Arbitrary Inhomogeneous Environment
Session 3P1b: Optics and Photonics 1Abstract| Control of spontaneously emitted light lies at the heart of quantum optics. It is
essential for diverse applications ranging from lasers, light-emitting diodes, solar cells, and quan-
tum information. According to the quantum electrodynamics theory, the spontaneous emission
(SE) of an atom can be a weak-coupling radiation process due to the vacuum °uctuations of
electromagnetic ¯eld. A suitable modi¯cation of inhomogeneous environment is required so that
the vacuum °uctuations controlling the SE can be manipulated. Inhibiting unwanted SE and
boosting desired ones will promote the novel optoelectronic designs tailored to industrial stan-
dard. The local density of states (LDOS) counts the number of electromagnetic modes where
photons can be emitted at the speci¯c location of the emitter, and can be interpreted as the
density of vacuum °uctuations. The inhibition or enhancement of SE boils down to how the
LDOS of photons is controlled.
In this work, the SE of the excited atoms in 2D arbitrary inhomogeneous environment has been
systematically studied. The LDOS determines the radiation dynamics of a point source (for
3D) or a line source (for 2D). In particular, it also determines the SE rate, and the LDOS
is represented by the electric dyadic Green's function. The numerical solution of the electric
Green's tensor has been accurately obtained by the ¯nite-di®erence frequency-domain method
with the proper approximations of the monopole and dipole sources. The SE of the atoms in
the photonic crystal and plasmonic metal plates has been comprehensively and comparatively
investigated. For both systems, the SE strongly depends on their respective dispersion relations
and could be modi¯ed or tuned by the ¯nite-structure or ¯nite-size e®ects. This work is important
for the SE engineering and optimized design of optoelectronic devices.published_or_final_versio
NMR studies of Successive Phase Transitions in Na0.5CoO2 and K0.5CoO2
59Co- and 23Na-NMR measurements have been carried out on polycrystalline and
c-axis aligned samples of Na0.5CoO2, which exhibits successive transitions at
temperatures T = 87 K (= Tc1) and T = 53 K (= Tc2). 59Co-NMR has also been
carried out on c-axis aligned crystallites of K0.5CoO2 with similar successive
transitions at Tc1 ~ 60 K and Tc2 ~ 20 K. For Na0.5CoO2, two sets of three NMR
lines of 23Na nuclei explained by considering the quadrupolar frequencies nuQ
~1.32 and 1.40 MHz have been observed above Tc1, as is expected from the
crystalline structure. Rather complicated but characteristic variation of the
23Na-NMR spectra has been observed with varying T through the transition
temperatures, and the internal fields at two crystallographically distinct Na
sites are discussed on the basis of the magnetic structures reported
previously. The internal fields at two distinct Co sites observed below Tc1 and
the 591/T1-T curves of Na0.5CoO2 and K0.5CoO2 are also discussed in a
comparative way.Comment: 7 pages, 10 figures, submitted to J. Phys. Soc. Jpn, correction is
made in right colum of p6 (35th line) as K0.5CoO2-->Na0.5CoO
Bethe ansatz for the SU(4) extension of the Hubbard Model
We apply the nested algebraic Bethe ansatz method to solve the eigenvalue
problem for the SU(4) extension of the Hubbard model. The Hamiltonian is
equivalent to the SU(4) graded permutation operator. The graded Yang-Baxter
equation and the graded Quantum Inverse Scattering Method are used to obtain
the eigenvalue of the SU(4) extension of the Hubbard model.Comment: Latex file, 12 page
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