459 research outputs found
Nematic domains and resistivity in an itinerant metamagnet coupled to a lattice
The nature of the emergent phase near a putative quantum critical point in
the bilayer ruthenate SrRuO has been a recent subject of intensive
research. It has been suggested that this phase may possess electronic nematic
order(ENO). In this work, we investigate the possibility of nematic domain
formation in the emergent phase, using a phenomenological model of electrons
with ENO and its coupling to lattice degrees of freedom. The resistivity due to
the scattering off the domain walls is shown to closely follow the ENO
parameter. Our results provide qualitative explanations for the dependence of
the resistivity on external magnetic fields in SrRuO.Comment: 4 pages, 4 figures, published versio
BERT-PIN: A BERT-based Framework for Recovering Missing Data Segments in Time-series Load Profiles
Inspired by the success of the Transformer model in natural language
processing and computer vision, this paper introduces BERT-PIN, a Bidirectional
Encoder Representations from Transformers (BERT) powered Profile Inpainting
Network. BERT-PIN recovers multiple missing data segments (MDSs) using load and
temperature time-series profiles as inputs. To adopt a standard Transformer
model structure for profile inpainting, we segment the load and temperature
profiles into line segments, treating each segment as a word and the entire
profile as a sentence. We incorporate a top candidates selection process in
BERT-PIN, enabling it to produce a sequence of probability distributions, based
on which users can generate multiple plausible imputed data sets, each
reflecting different confidence levels. We develop and evaluate BERT-PIN using
real-world dataset for two applications: multiple MDSs recovery and demand
response baseline estimation. Simulation results show that BERT-PIN outperforms
the existing methods in accuracy while is capable of restoring multiple MDSs
within a longer window. BERT-PIN, served as a pre-trained model, can be
fine-tuned for conducting many downstream tasks, such as classification and
super resolution
Proximity Effect in Nb/Au/CoFe Trilayers
We have investigated the superconducting critical temperatures of Nb/Au/CoFe
trilayers as a function of Au and CoFe thicknesses. Without the CoFe layer the
superconducting critical temperatures of Nb/Au bilayers as a function of Au
thickness follow the well-known proximity effect between a superconductor and a
normal metal. The superconducting critical temperatures of Nb/Au/CoFe trilayers
as a function of Au thickness exhibit a rapid initial increase in the small Au
thickness region and increase slowly to a limiting value above this region,
accompanied by a small oscillation of Tc. On the other hand, the
superconducting critical temperatures of Nb/Au/CoFe trilayers as a function of
CoFe thickness show non-monotonic behavior with a shallow dip feature. We
analyzed the Tc behavior in terms of Usadel formalism and found that most
features are consistent with the theory, although the small oscillation of Tc
as a function of the Au thickness cannot be accounted for. We have also found
quantitative values for the two interfaces: Nb/Au and Au/CoFe.Comment: 25 pages, 6 figure
Visual information priming in Internet of things: focusing on the interface of smart refrigerator
Internet of Things (IoT) supports an environment where users are able to interact and get information by sharing visual informational cues. The purpose of this study was to investigate what effect was made on the perceived usefulness, perceived ease of use, intention to use and self efficacy about use of smart refrigerator when visual information related to the food and function is provided in advance in the interface. A data was collected from a between-subjects experiment (N = 26) with an independent variable (priming visual information vs. non-priming).
According to the experiment results, users who were primed about the visual cues perceived higher usefulness (PU), ease of use (PEoU), intention to use (IU), and self-efficacy (SE) toward the fridge compared to the users in a non-primed group.The study proposes theoretical and practical implications for designing food-related smart home appliances’ interface and visual affordances
A Modified Sequence-to-point HVAC Load Disaggregation Algorithm
This paper presents a modified sequence-to-point (S2P) algorithm for
disaggregating the heat, ventilation, and air conditioning (HVAC) load from the
total building electricity consumption. The original S2P model is convolutional
neural network (CNN) based, which uses load profiles as inputs. We propose
three modifications. First, the input convolution layer is changed from 1D to
2D so that normalized temperature profiles are also used as inputs to the S2P
model. Second, a drop-out layer is added to improve adaptability and
generalizability so that the model trained in one area can be transferred to
other geographical areas without labelled HVAC data. Third, a fine-tuning
process is proposed for areas with a small amount of labelled HVAC data so that
the pre-trained S2P model can be fine-tuned to achieve higher disaggregation
accuracy (i.e., better transferability) in other areas. The model is first
trained and tested using smart meter and sub-metered HVAC data collected in
Austin, Texas. Then, the trained model is tested on two other areas: Boulder,
Colorado and San Diego, California. Simulation results show that the proposed
modified S2P algorithm outperforms the original S2P model and the
support-vector machine based approach in accuracy, adaptability, and
transferability
The intratumoral administration of ferucarbotran conjugated with doxorubicin improved therapeutic effect by magnetic hyperthermia combined with pharmacotherapy in a hepatocellular carcinoma model
BACKGROUND: Local hyperthermia of tumor in conjunction with chemotherapy is a promising strategy for cancer treatment. The aim of this study was to evaluate the efficacy of intratumoral delivery of clinically approved magnetic nanoparticles (MNPs) conjugated with doxorubicin to simultaneously induce magnetic hyperthermia and drug delivery in a hepatocellular carcinoma (HCC) model. MATERIALS AND METHODS: HCC cells expressing luciferase were implanted into the flank of BALB/c-nu mice (n = 19). When the tumor diameter reached 7–8 mm, the animals were divided into four groups according to the injected agents: group A (normal saline, n = 4), group B (doxorubicin, n = 5), group C (MNP, n = 5), and group D (MNP/doxorubicin complex, n = 5). Animals were exposed to an alternating magnetic field (AMF) to receive magnetic hyperthermia, and intratumoral temperature changes were measured. Bioluminescence imagings (BLIs) were performed before treatment and at 3, 7, and 14 days after treatment to measure the tumoral activities. The relative signal intensity (RSI) of each tumor was calculated by dividing the BLI signal at each time point by the value measured before treatment. At day 14 post-treatment, all tumor tissues were harvested to assess the apoptosis rates by pathological examination. RESULTS: The rise in temperature of the tumors was 1.88 ± 0.21°C in group A, 0.96 ± 1.05°C in B, 7.93 ± 1.99°C in C, and 8.95 ± 1.31°C in D. The RSI of the tumors at day 14 post-treatment was significantly lower in group D (0.31 ± 0.20) than in group A (2.23 ± 1.14), B (0.94 ± 0.47), and C (1.02 ± 0.21). The apoptosis rates of the tumors were 11.52 ± 3.10% in group A, 23.0 ± 7.68% in B, 25.4 ± 3.36% in C, and 39.0 ± 13.2% in D, respectively. CONCLUSIONS: The intratumoral injection of ferucarbotran conjugated with doxorubicin shows an improved therapeutic effect compared with doxorubicin or ferucarbotran alone when the complex is injected into HCC tissues exposed to AMF for magnetic hyperthermia. This strategy of combining doxorubicin and MNP-induced magnetic hyperthermia exhibits a synergic effect on inhibiting tumor growth in an HCC model
An ICA-Based HVAC Load Disaggregation Method Using Smart Meter Data
This paper presents an independent component analysis (ICA) based
unsupervised-learning method for heat, ventilation, and air-conditioning (HVAC)
load disaggregation using low-resolution (e.g., 15 minutes) smart meter data.
We first demonstrate that electricity consumption profiles on mild-temperature
days can be used to estimate the non-HVAC base load on hot days. A residual
load profile can then be calculated by subtracting the mild-day load profile
from the hot-day load profile. The residual load profiles are processed using
ICA for HVAC load extraction. An optimization-based algorithm is proposed for
post-adjustment of the ICA results, considering two bounding factors for
enhancing the robustness of the ICA algorithm. First, we use the hourly HVAC
energy bounds computed based on the relationship between HVAC load and
temperature to remove unrealistic HVAC load spikes. Second, we exploit the
dependency between the daily nocturnal and diurnal loads extracted from
historical meter data to smooth the base load profile. Pecan Street data with
sub-metered HVAC data were used to test and validate the proposed
methods.Simulation results demonstrated that the proposed method is
computationally efficient and robust across multiple customers
Nematic domains and resistivity in an itinerant metamagnet coupled to a lattice. Phys
The nature of the emergent phase near a putative quantum critical point in the bilayer ruthenate Sr 3 Ru 2 O 7 has been a recent subject of intensive research. It has been suggested that this phase may possess electronic nematic order (ENO). In this work, we investigate the possibility of nematic domain formation in the emergent phase, using a phenomenological model of electrons with ENO and its coupling to lattice degrees of freedom. The resistivity due to the scattering off the domain walls is shown to closely follow the ENO parameter. Our results provide qualitative explanations for the dependence of the resistivity on external magnetic fields in Sr 3 Ru 2 O 7 . DOI: 10.1103/PhysRevLett.98.126407 PACS numbers: 71.27.+a, 63.20.Kr, 71.10.ÿw, 75.30.Kz Quantum critical behavior in metamagnetism represents the most unusual critical phenomenon in itinerant electron systems. It was shown in a series of remarkable experiments that the critical end point associated with the metamagnetic transition (MMT) can be driven to zero temperature in the bilayer ruthenate Sr 3 Ru 2 O 7 by changing the angle between the external magnetic field and the c axis of the material Later experiments on the ultrapure samples, however, have shown that the quantum critical end point is eventually avoided when the finite temperature critical point is pushed further down to zero temperature, and is replaced by two consecutive MMTs Currently there exist two competing proposals for the nature of this emergent phase. Binz et al. [8] proposed a phenomenological Ginzburg-Landau theory of magnetic Condon domains and suggested that the high resistivity may come from the scattering of electrons off the magnetic domains. Another proposal involves the formation of electronic nematic order (ENO) in the emergent phase; namely, the Fermi surface of the electrons spontaneously breaks the lattice rotational symmetry Very recently it has been reported that the high resistivity seen in the emergent phase is insensitive to demagnetization factor or shapes of the samples In this Letter, we offer a theory of the nematic domain formation and the resulting high resistivity in the emergent phase. The possibility of the nematic domains has not been studied theoretically even though such possibility was briefly discussed in the literature In search for a concise description, we start with an effective electronic Hamiltonian that captures the essential physics of ENO, namely, we consider the quadrupolar interaction between electrons In view of the magnetostriction data indicating a close relationship between the lattice and the emergent phase [5], we also consider the electron-lattice interaction. Since we are studying an effective Hamiltonian, we are only interested in general properties of this Hamiltonian and the precise values of the parameters should not be taken seriously. Remarkably this simplified model contains essential ingredients of the nematic domain formation and the resulting high resistivity. It is found that the electron-lattice interaction makes the formation of the nematic domains (at finite temperatures) much more likely by offering a large number of metastable domain configurations. Another key result of our work is that the magnetic field dependence of the resistivity in the nematic domain phase closely follows the field dependence of the ENO parame-PRL 98
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