We explore the dexterous manipulation transfer problem by designing simulators. The task wishes to transfer human manipulations to dexterous robot hand simulations and is inherently difficult due to its intricate, highly-constrained, and discontinuous dynamics and the need to control a dexterous hand with a DoF to accurately replicate human manipulations. Previous approaches that optimize in high-fidelity black-box simulators or a modified one with relaxed constraints only demonstrate limited capabilities or are restricted by insufficient simulation fidelity. We introduce parameterized quasi-physical simulators and a physics curriculum to overcome these limitations. The key ideas are 1) balancing between fidelity and optimizability of the simulation via a curriculum of parameterized simulators, and 2) solving the problem in each of the simulators from the curriculum, with properties ranging from high task optimizability to high fidelity. We successfully enable a dexterous hand to track complex and diverse manipulations in high-fidelity simulated environments, boosting the success rate by 11\%+ from the best-performed baseline. The project website is available at https://meowuu7.github.io/QuasiSim/.
This article contrasts two periods of time in the Arve Valley, during which particular attention was paid to the links between human health and the environment, but with diametrically opposed perceptions. Historically, the Plateau d'Assy in the Arve Valley was a major healthcare destination, particularly specializing in the treatment of tuberculosis between the 1920s and 1970s. From the 19th century onwards, a collective imagination emerged around the myth of clean air of the mountains. Alpine regions broadly benefited from being considered particularly sanitary, and this was the engine of local tourism until the 1970s. Though the therapeutic characteristics of the mountains still exist today, scientific analyses carried out from the 1990s have underlined the great vulnerability of the Alpine valleys to atmospheric pollution. This is the case of the Arve Valley which, over the past two decades, has become infamous in the media for its poor air quality. Now understood to be a significant public health issue, air pollution in this region has become a major source of fear and anxiety for part of the local population. Though this contrasts sharply with past therapeutic representations of the mountains as mentioned above, current fears around air quality in the Arve Valley find themselves echoed in broader societal debates around environmental health and eco-anxiety.
Most urban applications necessitate building footprints in the form of concise vector graphics with sharp boundaries rather than pixel-wise raster images. This need contrasts with the majority of existing methods, which typically generate over-smoothed footprint polygons. Editing these automatically produced polygons can be inefficient, if not more time-consuming than manual digitization. This paper introduces a semi-automatic approach for building footprint extraction through semantically-sensitive superpixels and neural graph networks. We first learn to generate superpixels that are not only boundary-preserving but also semantically-sensitive. The superpixels respond exclusively to building boundaries rather than other natural objects. These intermediate superpixel representations can be naturally considered as nodes within a graph. Consequently, graph neural networks are employed to model the global interactions among all superpixels and enhance the representativeness of node features for building segmentation, which also enables efficient editing of segmentation results. Classical approaches are utilized to extract and regularize boundaries for the vectorized building footprints. We efficiently accomplish accurate segmentation outcomes by utilizing minimal clicks and straightforward strokes, eliminating the necessity for editing polygon vertices. A significant improvement of 8% in AP50 was observed in vector graphics evaluation, surpassing established techniques. Additionally, we have devised an optimized and sophisticated pipeline for interactive editing, poised to further augment the overall quality of the results. The code for training the superpixel and graph networks will be made publicly available upon publication.11 https://vrlab.org.cn/~hanhu/projects/spgraph/.
Fabio Luino, Mariano Barriendos, Fabrizio Terenzio Gizzi
et al.
This paper demonstrates how historical research is a valuable tool for identifying past geological, geomorphological and climatic hazards and therefore critical for mitigating and reducing future risk. The authors describe the potential of a scientific field that straddles that of the geologist, geographer, historian and archivist. Historical records include a range of materials and sources of information, which can be very diverse; from written documents to cartographies, and from drawings to marble tombstones. They are all useful and convey important data, on the date of the event, the size of the phenomena, sometimes on ground effects, damage or magnitude. The authors discuss how to conduct historical research by providing a list of locations and how important historical documents can be found. Works that mention geological phenomena are listed, starting with the first occasional descriptions by individuals in letters, up to very specific publications in individual fields of interest. With this introduction, the editors of the Special Issue wish to draw attention to the importance of historical documentation, which is too often ignored or considered of low priority by the scientific community, but can contain key information on events, their impacts and social and cultural adaptations.
Swakangkha Ghosh, George Philip, Anup K. Prasad
et al.
Owing to the increased availability of high-resolution satellite data and the rapid development of Geographic Information System (GIS) technology, the mapping of active faults and quantification of tectonic activity in inaccessible regions has exceedingly improved. We examined the tectonic activity in the Trans-Yamuna region of the NW Himalaya using geomorphic indices derived from a Digital Elevation Model (DEM). In addition, this study evaluates the sensitivity of four space-borne Digital Elevation Models (DEMs) with respect to TAN DEM-X (TerraSAR-X add-on for Digital Elevation Measurements). The Cartosat DEM, generated with a spatial resolution of 5 meters using state-of-the-art methods, demonstrated a reliable representation of topography. Geomorphic indices such as Asymmetry Factor (AF), Transverse Topography (TT), Hypsometric Integral (HI), Valley Floor width (Vf), Stream-length gradient index (SL), and Normalised steepness index (ksn) were computed for 41 sub-watersheds to determine the degree of tectonic activity. We infer that majority of the region is tectonically active, with upliftment continuing to occur in the north of the Main Boundary Thrust (MBT). Furthermore, the existence of mapped active faults north of the MBT further substantiates the fact that strain release is not only concentrated in the frontal Himalaya, but is distributed over a broader area above the decollement.
Wojciech Brzezicki, Filomena Forte, Canio Noce
et al.
The phenomenon of negative thermal expansion (NTE) deals with the increase of the lattice parameters and the volume of the unit cell when the material is thermally cooled. The NTE is typically associated with thermal phonons and anomalous spin-lattice coupling at low temperatures. However, the underlying mechanisms in the presence of strong electron correlations in multi-orbital systems are not yet fully established. Here, we investigate the role of Coulomb interaction in the presence of lattice distortions in setting out the NTE effect, by focusing on the physical case of layered Ca$_2$RuO$_4$ with $d^4$ configuration at each Ru ion site. We employ the Slater-Koster parametrization to describe the electron-lattice coupling through the dependence of the $d-p$ hybridization on the Ru-O-Ru bond angle. The evaluation of the minimum of the free energy at finite temperature by fully solving the multi-orbital many-body problem on finite size cluster allows us to identify the regime for which the system is prone to exhibit NTE effects. The analysis shows that the nature of the spin-orbital correlations is relevant to drive the reduction of the bond angle by cooling, and in turn the tendency toward a NTE. This is confirmed by the fact that a changeover of the electronic and orbital configuration from $d^4$ to $d^3$ by transition metal substitution is shown to favor the occurrence of NTE in Ca$_2$RuO$_4$. This finding is in agreement with the experimental observations of a NTE effect which is significantly dependent on the transition metal substitution in the Ca$_2$RuO$_4$ compound.
We investigate several distinct spectral crossovers amongst various integrable and quantum-chaotic limits of a 1D disordered quantum spin-1/2 model, by tuning the relative amplitudes of various Hamiltonian parameters to retain or break relevant unitary and antiunitary symmetries. Since we are specially interested in crossovers involving a Gaussian symplectic ensemble (GSE) limit, we carry out all our calculations with an odd number of spins that naturally results in eigenspectra with Kramers degeneracies. The various crossovers are investigated via detailed studies of both short-range (NNSD) and long-range (spectral rigidity and number variance) spectral correlations. The short-range studies show excellent agreement with RMT predictions. One of the highlights of this study is the systematic investigation of the consequences of retaining both eigenvalues corresponding to every Kramers doublet, in a crossover involving the GSE limit, and see how it evolves to a limit where the KD is naturally lifted. The NNSD plot in the GSE limit exhibits a Dirac delta peak at zero splitting and a renormalized GSE hump at finite splitting, whose general analytical form is derived. With an increasing symmetry breaking magnetic field the NNSD shows an interesting, dynamic two-peaked structure that finally converges to the standard GUE lineshape. We explain this trend in terms of a competition between the splittings amongst distinct Kramers doublets and the Zeeman-like splittings induced by a breaking of time-reversal symmetry. In the long-range spectral correlation studies, we shed light on the extent of agreement between our physical spin systems and RMT predictions. Our studies also show that the long-range correlations may serve to distinguish between the two Poissonian limits (nonlocalized and localized) in the reentrant crossovers, which the short-range correlations fail to distinguish.
The presented article is devoted to the study of modern trends in the spread of ice deposits on the territory of Ukraine in the last thirty years of 1991-2020 (new climate standard) relative to the period 1981-2010. recommended by WMO. The conducted research is related to the research work on the study of climate change carried out at the UkrSMI.
Question status. Despite certain achievements in the study of the distribution of ice-frost deposits in the territory of Ukraine in the past, the task of determining the existing trends and subsequent changes in their distribution under the influence of climate change remains unresolved.
The purpose of the study was to determine the current state and features of the distribution of the field of ice deposits on the territory of Ukraine with the identification of centers of increase and decrease in the average amount of such deposits, as well as trends relative to another observation period.
Materials and methods. Data of actual instrumental observations of ice deposits at all meteorological stations of Ukraine for two periods 1991-2020 and 1981-2010 were used for processing. The main research methods were physical-statistical with the determination of the normalized values of the number of cases of such deposits and cartographic with the visualization of the results. The information obtained is not only informative, since it reflects the current trends in the distribution of one of the types of ice-frost deposits, which are adverse weather phenomena, but also allows you to plan the work of weather-dependent industries in more detail, ensuring their uninterrupted operation.
Main results. It has been established that most of the deviations of the average number of ice cases for the study period relative to the period of 1981-2010. were insignificant, but in some areas during the cold season, especially in winter, they reached higher values. values. It has been established that in January and December there is a predominance of positive deviations of the average number of ice cases in Ukraine. Most of the centers of positive deviations are based on the territory of the western region from Volyn. Rivne and Zhytomyr regions to the Carpathians, as well as in the north of the Chernihiv and Sumy regions, as well as in a number of central regions from Vinnitsa to Poltava and Dnepropetrovsk regions. Also, noticeable foci of such deviations are observed in the north and east of the Kharkiv region, as well as in the north of the Luhansk region. They are noticeable in the south of the country. In February and March, foci of negative deviations were most often encountered. The most pronounced of them were observed in the western region in the territory from the Zhytomyr region to the Carpathian region, as well as in some central regions. In February, a focus of positive deposits was discovered in the north of the Chernihiv region. In April-October, the field of ice deposits for 1991-2020. compared to 1981-2010 practically did not change. In November, an increase in the number and spatial distribution of positive deviations of the average amount of ice deposits was revealed. They were mainly distributed in the central regions from Vinnitsa to the Poltava and Dnepropetrovsk regions, as well as in the east of the Kharkiv region and the north of the Luhansk region.
Fabrice Amisi Muvundja, Fabrice Amisi Muvundja, Jacques Riziki Walumona
et al.
Hydroelectric power (HP) represents the main source of electricity in Africa, including the Democratic Republic of Congo. The demand for new dam construction is high, and major projects are currently progressing through planning and implementation stages. New HP dams should comply with both past and emerging environmental requirements. River systems need water to maintain hydraulic and ecological functions. Flow regime disturbance can prevent rivers from providing their ecosystem services and disrupt riparian communities. Most dammed rivers in Africa are understudied, however, in terms of their environmental flow requirements. This study analysed the hydrological regime and water quality of the Ruzizi River. The research investigated conditions of minimum water flow and hydropeaking at the Ruzizi I HP dam in terms of land management constraints and ecological impacts. According to Gumbel’s hydrological model, a discharge of ∼130 m3/s showed the longest return period (12 years) among the most recurrent flows. By contrast, the maximum recorded discharge of 143 m3/s showed a return time of 76 years. Any discharge between 46 and 120 m3/s could occur at any time within three years. The discharge–hydropower production relationship for the power plant provided a possible minimum environmental flow of 28 m3/s (i.e., 25%). Drinking water quality was assessed according to WHO water quality index (WQI) standards. Turbidity (i.e., total suspended solids) upstream and downstream of dams correlated strongly with rainfall (r = 0.8; n = 12) and land use. WQI values observed in excess of WHO drinking water standards indicate that the Ruzizi River is currently unsuitable for drinking water purposes.
One of the subject areas that is currently most prominent in the field of education (Social Science) is climate change, given its implications for raising awareness and training the present and future society. The objectives of this study, focused on school children (Primary Education—10 to 12 years old; third cycle, Secondary Education—12–16 years old; and pre-university, Baccalaureate—17–18 years old) in the Region of Valencia (Spain), are to analyse the following: the main information channels through which children receive information on climate change; the causes and consequences that they identify with respect to this phenomenon; and the main greenhouse gas that they believe is in the atmosphere. Based on the 575 students surveyed during the academic year 2020–2021, the results indicate that the three main information media are digital (TV—82.8%, Internet—56.2% and social networks—49.4%). With respect to the causes of the phenomenon identified by the students, particularly noteworthy was pollution (70.1%) and, in terms of the effects, the increase and changes in temperature (61.7%) were of particular note. Finally, with reference to greenhouse gases, the majority responded CO<sub>2</sub> (63.5%). This is incorrect, as the main greenhouse gas in the atmosphere is water vapour. To sum up, we can highlight the role played by schools in training the future society and the risk arising from an increase in the information received from digital media by children as they grow older, due to the danger of misinformation.
Luc Darmé, Giovanni Grilli di Cortona, Enrico Nardi
Recent lattice determinations of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment $a_μ^{\rm HVP}$ have confirmed the discrepancy with the data-driven dispersive method. In the meanwhile the CMD-3 collaboration has reported a result for the $e^+e^-\to π^+π^-$ cross section considerably larger than previous experimental results (and close to the lattice determinations) exacerbating the discordance between different $e^+e^-$ datasets. We explore to what extent these disagreements can be accounted for by some new physics effect altering selectively the individual experimental determinations of $σ(e^+e^- \to\;$hadrons). We find that specific effects of GeV-scale new particles are able to shift upwards the KLOE and BaBar results in the low and intermediate energy windows, while leaving unaffected the CMD-3 energy scan. Although these new physics effects cannot fully explain all the discrepancies among the different $σ(e^+e^- \to\;$hadrons) datasets, they succeed in mitigating the overall tension between data-driven and lattice estimates of $a_μ^{\rm HVP}$. Remarkably, the additional loop corrections involving the new particles concur to solve the residual discrepancy with the experimental value of $(g-2)_μ$.
Detection and classification of entanglement properties of a multi-qubit system is a topic of great interest. This topic has been studied extensively and thus we found different approaches for the detection and classification of multi-qubit entangled states. We have applied partial transposition operation on one of the qubit of the three-qubit system and then studied the entanglement properties of the three-qubit system, which is under investigation. Since the partial transposition operation is not a quantum operation so we have approximated partial transposition operation in such a way so that it represent a completely positive map. The approximated partial transposition operation is also known as structural physical approximation of partial transposition (SPA-PT). We have studied in detail the application of SPA-PT on a three qubit system and provided explicitly the matrix elements of the density matrix describing SPA-PT of a three qubit system. Moreover, we propose criterion to classify all possible stochastic local operations and classical communication(SLOCC) inequivalent classes of a pure as well as mixed three qubit state through SPA-PT map, which makes our criterion experimentally realizable. We have illustrated our criterion for detection and classification of three-qubit entangled states by considering few examples.
Since the $^4$He dimer supports only one weakly bound state with an average interatomic distance much larger than the van der Waals length and no deeply bound states, $^4$He$_N$ clusters with $N>2$ are a paradigmatic model system with which to explore foundational concepts such as large $s$-wave scattering length universality, van der Waals universality, Efimov physics, and effective field theories. This work presents structural properties such as the pair and triple distribution functions, the hyperradial density, the probability to find the $N$th particle at a given distance from the center of mass of the other $N-1$ atoms, and selected contacts. The kinetic energy release, which can be measured via Coulomb explosion in dedicated size-selected molecular beam experiments -- at least for small $N$ -- , is also presented. The structural properties are determined for three different realistic $^4$He-$^4$He interaction potentials and contrasted with those for an effective low-energy potential model from the literature that reproduces the energies of $^4$He$_N$ clusters in the ground state for $N=2$ to $N=\infty$ at the $\gtrsim 95$~percent level with just four input parameters. The study is extended to unitarity (infinite $s$-wave scattering length) by artificially weakening the interaction potentials. In addition to contributing to the characterization of small bosonic helium quantum droplets, our study provides insights into the effective low-energy theory's predictability of various structural properties.
Lara Schleifenbaum, Julie C. Driebe, Tanja M. Gerlach
et al.
How attractive we find ourselves decides who we target as potential partners and influences our reproductive fitness. Self-perceptions on women's fertile days could be particularly important. However, results on how self-perceived attractiveness changes across women's ovulatory cycles are inconsistent and research has seldomly assessed multiple attractiveness-related constructs simultaneously. Here, we give an overview of ovulatory cycle shifts in self-perceived attractiveness, sexual desirability, grooming, self-esteem and positive mood. We addressed previous methodological shortcomings by conducting a large, preregistered online diary study of 872 women (580 naturally cycling) across 70 consecutive days, applying several robustness analyses and comparing naturally cycling women with women using hormonal contraceptives. As expected, we found robust evidence for ovulatory increases in self-perceived attractiveness and sexual desirability in naturally cycling women. Unexpectedly, we found moderately robust evidence for smaller ovulatory increases in self-esteem and positive mood. Although grooming showed an ovulatory increase descriptively, the effect was small, failed to reach our strict significance level of .01 and was not robust to model variations. We discuss how these results could follow an ovulatory increase in sexual motivation while calling for more theoretical and causally informative research to uncover the nature of ovulatory cycle shifts in the future.