16,632 research outputs found
Residential electricity pricing in China
The paper aims to evaluate the implications of the new residential pricing system in China by examining price and income elasticity of demand by different household types. We use pre-reform annual panel data for 29 provinces over a fourteen year period, from 1998 to 2011, applying feasible generalize least squares models. The price and income elasticities for household sector are -0.412, and 1.476 at nation level, -0.300 and 1.550 in urban areas and -0.522 and 1.093 in rural areas respectively. With regional effects, the price and income elasticities are -0.146 and 1.286 for urban households in coastal provinces and -0.772 and 1.259 for urban households in inland provinces respectively. The empirical results reveal that there is important heterogeneity in the responsiveness to electricity price changes according to household income level and location
Roboteye technology for thermal target tracking using predictive control
© ISARC 2018 - 35th International Symposium on Automation and Robotics in Construction and International AEC/FM Hackathon: The Future of Building Things. All rights reserved. Thermal cameras are widely used in the fatigue analysis of mechanical structures using the thermoelastic effect. Nevertheless, such analysis is hampered due to blurry images resulting from the motion of structure-under-test. To address the issue this paper presents a system that utilizes robotic vision and predictive control. The system comprises of a thermal camera, a vision camera, a RobotEye, and a fiducial detection system. A marker is attached to a thermal target in order to estimate its position and orientation using the proposed detection system. To predict the future position of the thermal moving object, a Kalman filter is used. Finally, the Model Predictive Control (MPC) approach is applied to generate commands for the robot to follow the target. Results of the tracking by MPC are included in this paper along with the performance evaluation of the whole system. The evaluation clearly shows the improvement in the tracking performance of the development for thermal structural analysis
Resource Allocation for Cell-Free Massive MIMO-aided URLLC Systems Relying on Pilot Sharing
Resource allocation is conceived for cell-free (CF) massive multi-input multi-output (MIMO)-aided ultra-reliable and low latency communication (URLLC) systems. Specifically, to support multiple devices with limited pilot overhead, pilot reuse among the users is considered, where we formulate a joint pilot length and pilot allocation strategy for maximizing the number of devices admitted. Then, the pilot power and transmit power are jointly optimized while simultaneously satisfying the devices’ decoding error probability, latency, and data rate requirements. Firstly, we derive the lower bounds (LBs) of ergodic data rate under finite channel blocklength (FCBL). Then, we propose a novel pilot assignment algorithm for maximizing the number of devices admitted. Based on the pilot allocation pattern advocated, the weighted sum rate (WSR) is maximized by jointly optimizing the pilot power and payload power. To tackle the resultant NP-hard problem, the original optimization problem is first simplified by sophisticated mathematical transformations, and then approximations are found for transforming the original problems into a series of subproblems in geometric programming (GP) forms that can be readily solved. Simulation results demonstrate that the proposed pilot allocation strategy is capable of significantly increasing the number of admitted devices and the proposed power allocation achieves substantial WSR performance gain
Prospects of cold dark matter searches with an ultra-low-energy germanium detector
The report describes the research program on the development of
ultra-low-energy germanium detectors, with emphasis on WIMP dark matter
searches. A threshold of 100 eV is achieved with a 20 g detector array,
providing a unique probe to the low-mas WIMP. Present data at a surface
laboratory is expected to give rise to comparable sensitivities with the
existing limits at the WIMP-mass range. The projected
parameter space to be probed with a full-scale, kilogram mass-range experiment
is presented. Such a detector would also allow the studies of neutrino-nucleus
coherent scattering and neutrino magnetic moments.Comment: 3 pages, 4 figures, Proceedings of TAUP-2007 Conferenc
Coherency in Neutrino-Nucleus Elastic Scattering
Neutrino-nucleus elastic scattering provides a unique laboratory to study the
quantum mechanical coherency effects in electroweak interactions, towards which
several experimental programs are being actively pursued. We report results of
our quantitative studies on the transitions towards decoherency. A parameter
() is identified to describe the degree of coherency, and its
variations with incoming neutrino energy, detector threshold and target nucleus
are studied. The ranges of which can be probed with realistic neutrino
experiments are derived, indicating complementarity between projects with
different sources and targets. Uncertainties in nuclear physics and in
would constrain sensitivities in probing physics beyond the standard model. The
maximum neutrino energies corresponding to >0.95 are derived.Comment: 5 pages, 4 figures, 3 tables. V2 -- Published Versio
Multiple source transfer learning for dynamic multiobjective optimization
Recently, dynamic multiobjective evolutionary algorithms (DMOEAs) with transfer learning have become popular for solving dynamic multiobjective optimization problems (DMOPs), as the used transfer learning methods in DMOEAs can effectively generate a good initial population for the new environment. However, most of them only transfer non-dominated solutions from the previous one or two environments, which cannot fully exploit all historical information and may easily induce negative transfer as only limited knowledge is available. To address this problem, this paper presents a multiple source transfer learning method for DMOEA, called MSTL-DMOEA, which runs two transfer learning procedures to fully exploit the historical information from all previous environments. First, to select some representative solutions for knowledge transfer, one clustering-based manifold transfer learning is run to cluster non-dominated solutions of the last environment to obtain their centroids, which are then fed into the manifold transfer learning model to predict the corresponding centroids for the new environment. After that, multiple source transfer learning is further run by using multisource TrAdaboost, which can fully exploit information from the above centroids in new environment and old centroids from all previous environments, aiming to construct a more accurate prediction model. This way, MSTL-DMOEA can predict an initial population with better quality for the new environment. The experimental results also validate the superiority of MSTL-DMOEA over several competitive state-of-the-art DMOEAs in solving various kinds of DMOPs
Constraints on millicharged particles with low threshold germanium detectors at Kuo-Sheng Reactor Neutrino Laboratory
Relativistic millicharged particles () have been proposed in various
extensions to the Standard Model of particle physics. We consider the scenarios
where they are produced at nuclear reactor core and via interactions of
cosmic-rays with the earth's atmosphere. Millicharged particles could also be
candidates for dark matter, and become relativistic through acceleration by
supernova explosion shock waves. The atomic ionization cross section of
with matter are derived with the equivalent photon approximation.
Smoking-gun signatures with significant enhancement in the differential cross
section are identified. New limits on the mass and charge of are
derived, using data taken with a point-contact germanium detector with 500g
mass functioning at an energy threshold of 300~eV at the Kuo-Sheng Reactor
Neutrino Laboratory.Comment: 8 pages, 7 figure
Constraints on Non-Commutative Physics Scale with Neutrino-Electron Scattering
Neutrino-electron scatterings () are purely leptonic processes with
robust Standard Model (SM) predictions. Their measurements can therefore
provide constraints to physics beyond SM. Non-commutative (NC) field theories
modify space-time commutation relations, and allow neutrino electromagnetic
couplings at the tree level. Their contribution to neutrino-electron scattering
cross-section was derived. Constraints were placed on the NC scale parameter
from experiments with reactor and accelerator
neutrinos. The most stringent limit of at 95%
confidence level improves over the direct bounds from collider experiments.Comment: 6 pages, 2 figures, 2 tables, V2: minor revisions to match published
versio
Oxic and anoxic conditions affect arsenic (As) accumulation and arsenite transporter expression in rice
Arsenic (As) exposure from rice consumption has now become a global health issue. This study aimed to investigate the effects of rice rhizosphere oxic conditions on silicate transporter (responsible for arsenite transportation) expressions, and on As accumulation and speciation in four rice genotypes, including two hybrid genotypes (Xiangfengyou9, Shenyou9586) and two indica subspecies (Xiangwanxian17, Xiangwanxian12). Oxic and anoxic treatments have different effects on root length (p < 0.001) and weight (p < 0.05). Total As concentrations in roots were dramatically lower in oxic treatments (88.8–218 mg/kg), compared to anoxic treatments (147–243 mg/kg) (p < 0.001). Moreover, root and shoot arsenite concentrations in oxic treatments were lower than that in anoxic treatments in arsenite treatments. The relative abundance of silicate transporter expressions displayed a trend of down-regulation in oxic treatments compared to anoxic treatments, especially significantly different for Xiangwanxian17, Xiangwanxian12 in Lsi1 expressions (p < 0.05), Xiangfengyou9, Shenyou9586, Xiangwanxian17 in Lsi2 expressions (p < 0.05). However, there were no significant differences of transporter expressions in different As treatments and genotypes. It may be a possible reason for low As accumulation in rice growing aerobically compared to flooded condition and a potential route to reduce the health risk of As in rice
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