Advanced Hough-based method for on-device document localization

The demand for on-device document recognition systems increases in conjunction with the emergence of more strict privacy and security requirements. In such systems, there is no data transfer from the end device to a third-party information processing servers. The response time is vital to the user experience of on-device document recognition. Combined with the unavailability of discrete GPUs, powerful CPUs, or a large RAM capacity on consumer-grade end devices such as smartphones, the time limitations put significant constraints on the computational complexity of the applied algorithms for on-device execution. In this work, we consider document location in an image without prior knowledge of the docu-ment content or its internal structure. In accordance with the published works, at least 5 systems offer solutions for on-device document location. All these systems use a location method which can be considered Hough-based. The precision of such systems seems to be lower than that of the state-of-the-art solutions which were not designed to account for the limited computational resources. We propose an advanced Hough-based method. In contrast with other approaches, it accounts for the geometric invariants of the central projection model and combines both edge and color features for document boundary detection. The proposed method allowed for the second best result for SmartDoc dataset in terms of precision, surpassed by U-net like neural network. When evaluated on a more challenging MIDV-500 dataset, the proposed algorithm guaranteed the best precision compared to published methods. Our method retained the applicability to on-device computations.

A new species of Procambarus (Decapoda, Cambaridae) from the State of Querétaro, Mexico

With a Nearctic distribution, the family Cambaridae harbors a high species richness in Mexico, which is also evident along the Pánuco River catchment. A series of surveys carried on in five populations from the Sierra Gorda Biosphere Reserve in the State of Querétaro resulted in localizing a putative new species for science. A molecular phylogenetic study and species delimitation analyses including all the known Procambarus species from the Pánuco River catchment were conducted based on three mitochondrial genes (16S rDNA, 12S rDNA, and COI; 2,462 bp in total). Phylogeny recovered all species as monophyletic, including the populations under study. All delimitation results based on barcoding, ABGD, GMYC, bPTP, and gonopod differentiation agree in the recognition of a new taxon, to which the name Procambarus xihuisp. nov. is given, and its diagnosis and description are provided. The new species can be distinguished from the remaining species in the genus, among other characters, by a unique configuration of the terminal elements of the first pleopod of form I male, which includes a central projection lamellate, hood-like, forming a concave blade-like structure mesially directed, as well as a caudal process crest-like, mesiodistally directed, forming a lateral side of the concavity.

Socioeconomic Effects of COVID-19 Pandemic: Exploring Uncertainty in the Forecast of the Romanian Unemployment Rate for the Period 2020–2023

During the health crisis, it is vital to protect not only the critical sectors of the economy, the assets, technology, and infrastructure, but first and foremost, it is fundamental to protect jobs and workers. The current COVID-19 pandemic has had a strong impact on the labor market from three main perspectives: number of jobs (through unemployment and underemployment), quality of work (through wages, or access to social protection), and through the effects on specific groups, with a higher degree of vulnerability to unfavorable labor market outcomes. The measures aiming to reduce economic activity and social contacts lead to a reduction of labor demand and implicitly to the increase of the unemployment rate. In this context, it becomes even more relevant to be able to monitor the unemployment rate, providing relevant forecasts that include the effects of market shocks. Thus, our paper aims to forecast the unemployment rate for the period 2020–2023 using the Box-Jenkins methodology based on ARIMA models, exploring also the uncertainty based on fan charts. Although the baseline forecast offers valuable information, a good understanding of risks and uncertainties related to this forecast is equally important. The empirical results highlighted an ascending trend for unemployment rate during 2020, followed by a slow and continuous decrease until the end of 2023 with a high probability for the forecast to be above the central projection.

Efferent and Afferent Connections of the Supratrigeminal Neurons Conveying Orofacial Muscle Proprioception in Rats

The supratrigeminal nucleus (Su5) is a key structure for controlling jaw-movements since it receives proprioceptive sensation from jaw-closing muscle spindles (JCMSs) and sends projection to the trigeminal motor nucleus (Mo5). However, the central projection and regulation of JCMS proprioceptive sensation have not been fully understood. Therefore, we aimed to reveal the efferents and afferents of the Su5 by means of neuronal tract tracings. Anterograde tracer injections into the Su5 revealed that the Su5 sent contralateral projections (or bilateral projections with a contralateral predominance) to the Su5, basilar pontine nuclei, pontine reticular nucleus, deep mesencephalic nucleus, superior colliculus, caudo-ventromedial edge of ventral posteromedial thalamic nucleus, parafascicular thalamic nucleus, zona incerta, and lateral hypothalamus, and ipsilateral projections (or bilateral projections with an ipsilateral predominance) to the intertrigeminal region, trigeminal oral subnucleus, dorsal medullary reticular formation, and hypoglossal nucleus as well as the Mo5. Retrograde tracer injections into the Su5 demonstrated that the Su5 received bilateral projections with a contralateral predominance (or contralateral projections) from the primary and secondary somatosensory cortices, granular insular cortex and Su5, and ipsilateral projections (or bilateral projections with an ipsilateral predominance) from the dorsal peduncular cortex, bed nuclei of stria terminalis, central amygdaloid nucleus, lateral hypothalamus, parasubthalamic nucleus, trigeminal mesencephalic nucleus, parabrachial nucleus, juxtatrigeminal region, trigeminal oral and caudal subnuclei, and dorsal medullary reticular formation. These findings suggest that the Su5 receiving JCMS proprioceptive sensation has efferent and afferent connections with multiple brain regions, which are involved in emotional and autonomic functions as well as orofacial motor functions.

On the Reconstruction of the Center of a Projection by Distances and Incidence Relations

Up to an orientation-preserving symmetry, photographic images are produced by a central projection of a restricted area in the space into the image plane. To obtain reliable information about physical objects and the environment through the process of recording is the basic problem of photogrammetry. We present a reconstruction process based on distances from the center of projection and incidence relations among the points to be projected. For any triplet of collinear points in the space, we construct a surface of revolution containing the center of the projection. It is a generalized conic that can be represented as an algebraic surface. The rotational symmetry allows us to restrict the investigations to the defining polynomial of the profile curve in the image plane. An equivalent condition for the boundedness is given in terms of the input parameters, and it is shown that the defining polynomial of the profile curve is irreducible.

A new wood-inhabiting mite species of the genus Dendroseius Karg, 1965 (Acari, Mesostigmata, Rhodacaridae) from Central Europe (Slovakia)

A new rhodacarid mite of the genus Dendroseius Karg, 1965, D. reductussp. nov., was described based on females found in wood detritus and under bark of dead and dying poplar trees in a flood-plain forest in South Slovakia. The new species is unusual among the known congeners in the specifically formed triramous epistome of which the central projection is reduced in length, truncate, and markedly shorter than lateral ones. In other congeneric species, the anterior margin of the epistome possesses three pointed projections of similar size. A dichotomous key for identification of females of the world species classified in the genus Dendroseius is provided.

Feature Detection of Focused Plenoptic Camera Based on Central Projection Stereo Focal Stack

Fast and accurate feature extraction can lay a solid foundation for scene reconstruction and visual odometry. However, this has been rather a difficult problem for the focused plenoptic camera. In this paper, to the best of our knowledge, we first introduce an accurate and fast feature extraction algorithm based on central projection stereo focal stack (CPSFS). Specifically, we propose a refocusing algorithm that conforms to the central projection with regard to the center of main lens, which is more accurate than traditional one. On this basis, the feature is extracted on the CPSFS without calculating dense depth maps and total focus images. We verify the precision and efficiency of the proposed algorithm through simulated and real experiments, and give an example of scene reconstruction based on the proposed method. The experimental results show that our feature extraction algorithm is able to support the feature-based scene reconstruction via focused plenoptic camera.