34 research outputs found

    Machine learning-based estimation of buildings' characteristics employing electrical and chilled water consumption data: Pipeline optimization

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    Smart meter-driven remote auditing of buildings, as an alternative to the labor-intensive on-site visits, permits large-scale and rapid identification of buildings with low energy performance. The existing literature has mainly focused on electricity meters' data from a rather small set of buildings and efforts have often not been made to facilitate the models' physical interpretability. Accordingly, the present work focuses on the implementation and optimization of ML-based pipelines for building characterization (by use type (A), performance class (B), and operation group (C)) employing hourly electrical and chilled-water consumption data. Utilizing the Building Data Genome Project II dataset (with data from 1636 buildings), feature generation, feature selection, and pipeline optimization steps are performed for each pipeline. Results demonstrate that performing the latter two steps improves the model's accuracy (5.3%, 2.9%, and 3.9% for pipelines A, B, and C compared to a benchmark model), while notably reduces the number of utilized features (94.7%, 88.3%, 89.4%), enhancing the models' interpretability. Furthermore, adding features extracted from chilled-water consumption data boosts the accuracy (with respect to baseline) for the second subset by 12.4%, 13.5%, and 7.2%, while decreasing the feature count by 97.2%, 96.4%, and 96.5%, respectively.publishedVersio

    On the Reliability of Photometric and Spectroscopic Tracers of Halo Relaxation

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    We characterize the relaxation state of galaxy systems by providing an assessment of the reliability of the photometric and spectroscopic probe via the semianalytic galaxy evolution model. We quantify the correlations between the dynamical age of simuglated galaxy groups and popular proxies of halo relaxation in observation, which are mainly either spectroscopic or photometric. We find the photometric indicators demonstrate a stronger correlation with the dynamical relaxation of galaxy groups compared to the spectroscopic probes. We take advantage of the Anderson Darling statistic (A(2)) and the velocity segregation (Delta V) as our spectroscopic indicators, and use the luminosity gap (Delta m(12)) and the luminosity decentering (D-offset) as photometric ones. First, we find that a combination of Delta m(12) and D-offset evaluated by a bivariant relation (B = 0.04 x Delta m(12) - 0.11 x Log(Doff-set) + 0.28) shows a good correlation with the dynamical age compared to all other indicators. Second, by using the observational X-ray surface brightness map, we show that the bivariant relation brings about some acceptable correlations with X-ray proxies. These correlations are as well as the correlations between A(2) and X-ray proxies, offering a reliable yet fast and economical method of quantifying the relaxation of galaxy systems. This study demonstrates that using photometric data to determine the relaxation status of a group will lead to some promising results that are comparable with the more expensive spectroscopic counterpart.Peer reviewe

    The EDIBLES Survey. VII. A survey of C2 and C3 in interstellar clouds

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    We carried out a sensitive survey of C2_2 and C3_3 using the EDIBLES data set. We also expanded our searches to C4_4, C5_5, and 13^{13}C12^{12}C isotopologue in the most molecule-rich sightlines. We fit synthetic spectra generated following a physical excitation model to the C2_2 (2-0) Phillips band to obtain the C2_2 column density (NN) as well as the kinetic temperature (TkinT_\textrm{kin}) and number density (nn) of the host cloud. The C3_3 molecule was measured through its A~−X~\tilde{A} - \tilde{X} (000-000) electronic origin band system. We simulated the excitation of this band with a double-temperature Boltzmann distribution. We present the largest combined survey of C2_2 and C3_3 to date in which the individual transitions can be resolved. In total we detected C2_2 in 51 velocity components along 40 sightlines, and C3_3 in 31 velocity components along 27 sightlines. The two molecules are detected in the same velocity components. We find a very good correlation between NN(C2_2) and NN(C3_3) with Pearson r=0.93r = 0.93 and an average NN(C2_2)/NN(C3_3) ratio of 15.5±\pm1.4. A comparison with the behaviour of the C2_2 DIBs shows that there are no clear differences among sightlines with and without detection of C2_2 and C3_3. This is in direct contrast to the better-studied non-C2_2 DIBs who have reduced strengths in molecule-rich environments. We also identify for the first time the QQ(2), QQ(3), and QQ(4) transitions of the 13^{13}C12^{12}C (2-0) Phillips band in a stacked average spectrum, and estimate the isotopic ratio of carbon 12^{12}C/13^{13}C as 79±\pm8. Our search for the C4_4 and C5_5 optical bands was unsuccessful.Comment: 31 pages, 23 figures. To appear in A&

    The effect of acceptance and commitment therapy on insomnia and sleep quality: A systematic review

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    Background Acceptance and Commitment Therapy (ACT), as a type of behavioral therapy, attempts to respond to changes in people’s performance and their relationship to events. ACT can affect sleep quality by providing techniques to enhance the flexibility of patients’ thoughts, yet maintaining mindfullness. Therefore, for the first time, a systematic review on the effects of ACT on sleep quality has been conducted. Methods This systematic review was performed to determine the effect of ACT on insomnia and sleep quality. To collect articles, the PubMed, Web of Science (WOS), Cochrane library, Embase, Scopus, Science Direct, ProQuest, Mag Iran, Irandoc, and Google Scholar databases were searched, without a lower time-limit, and until April 2020. Results Related articles were derived from 9 research repositories, with no lower time-limit and until April 2020. After assessing 1409 collected studies, 278 repetitive studies were excluded. Moreover, following the primary and secondary evaluations of the remaining articles, 1112 other studies were removed, and finally a total of 19 intervention studies were included in the systematic review process. Within the remaining articles, a sample of 1577 people had been assessed for insomnia and sleep quality. Conclusion The results of this study indicate that ACT has a significant effect on primary and comorbid insomnia and sleep quality, and therefore, it can be used as an appropriate treatment method to control and improve insomnia

    Compressed Sensing of Sparse Multipath MIMO Channels with Superimposed Training Sequence

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    Recent advances in multiple-input multiple-output (MIMO) systems have renewed the interests of researchers to further explore this area for addressing various dynamic challenges of emerging radio communication networks. Various measurement campaigns reported recently in the literature show that physical multipath MIMO channels exhibit sparse impulse response structure in various outdoor radio propagation environments. Therefore, a comprehensive physical description of sparse multipath MIMO channels is presented in first part of this paper. Superimposing a training sequence (low power, periodic) over the information sequence offers an improvement in the spectral efficiency by avoiding the use of dedicated time/frequency slots for the training sequence, which is unlike the traditional schemes. The main contribution of this paper includes three superimposed training (SiT) sequence based channel estimation techniques for sparse multipath MIMO channels. The proposed techniques exploit the compressed sensing theory and prior available knowledge of channel’s sparsity. The proposed sparse MIMO channel estimation techniques are named as, SiT based compressed channel sensing (SiT-CCS), SiT based hardlimit thresholding with CCS (SiT-ThCCS), and SiT training based match pursuit (SiT-MP). Bit error rate (BER) and normalized channel mean square error are used as metrics for the simulation analysis to gauge the performance of proposed techniques. A comparison of the proposed schemes with a notable first order statistics based SiT least squares (SiT-LS) estimation technique is presented to establish the improvements achieved by the proposed schemes. For sparse multipath time-invariant MIMO communication channels, it is observed that SiT-CCS, SiT-MP, and SiT-ThCCS can provide an improvement up to 2, 3.5, and 5.2 dB in the MSE at signal to noise ratio (SNR) of 12 dB when compared to SiT-LS, respectively. Moreover, for BER=10 −1.9 BER=10−1.9, the proposed SiT-CCS, SiT-MP, and SiT-ThCCS, compared to SiT-LS, can offer a gain of about 1, 2.5, and 3.5 dB in the SNR, respectively. The performance gain in MSE and BER is observed to improve with an increase in the channel sparsity

    The ESO Diffuse Interstellar Bands Large Exploration Survey EDIBLES: I. Project description, survey sample and quality assessment

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    The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C+ 60 fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort to systematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectraltype stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R ~ 70 000 – 100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305–1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided
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