A survey on the application of path-planning algorithms for multi-rotor UAVs in precision agriculture

Multi-rotor Unmanned Aerial Vehicles (UAVs), although originally designed and developed for defence and military purposes, in the last ten years have gained momentum, especially for civilian applications, such as search and rescue, surveying and mapping, and agricultural crops and monitoring. Thanks to their hovering and Vertical Take-Off and Landing (VTOL) capabilities and the capacity to carry out tasks with complete autonomy, they are now a standard platform for both research and industrial uses. However, while the flight control architecture is well established in the literature, there are still many challenges in designing autonomous guidance and navigation systems to make the UAV able to work in constrained and cluttered environments or also indoors. Therefore, the main motivation of this work is to provide a comprehensive and exhaustive literature review on the numerous methods and approaches to address path-planning problems for multi-rotor UAVs. In particular, the inclusion of a review of the related research in the context of Precision Agriculture (PA) provides a unified and accessible presentation for researchers who are initiating their endeavours in this subject.

Sp(4) gauge theories and beyond the standard model physics

We review numerical results for models with gauge group Sp(2N), discussing the glueball spectrum in the large-N limit, the quenched meson spectrum of Sp(4) with Dirac fermions in the fundamental and in the antisymmetric representation and the Sp(4) gauge model with two dynamical Dirac flavours. We also present preliminary results for the meson spectrum in the Sp(4) gauge theory with two fundamental and three antisymmetric Dirac flavours. The main motivation of our programme is to test whether this latter model is viable as a realisation of Higgs compositeness via the pseudo Nambu Goldstone mechanism and at the same time can provide partial top compositeness. In this respect, we report and briefly discuss preliminary results for the mass of the composite baryon made with two fundamental and one antisymmetric fermion (chimera baryon), whose physical properties are highly constrained if partial top compositeness is at work. Our investigation shows that a fully non-perturbative study of Higgs compositeness and partial top compositeness in Sp(4) is within reach with our current lattice methodology.

Disciplined Teams vs. Agile Teams

Software development has been considered a socio-technical activity over the past decades. Particularly, in the case of software engineering, the necessity to communicate effectively with stakeholders and team members has been progressively emphasized. Human resources play a critical role in the success of software projects. Many techniques, methods, tools, models, and methodologies have been proposed, applied, and improved in order to help and ease the management of the software development process. Regardless of the software development methodology adopted, delivering a quality product in a predictable, efficient, and responsive manner is the objective for every team. Disciplined and Agile teams have different characteristics, but also share common aspects when working to accomplish their goals. The main motivation of this chapter is to present the differences and similarities of both teams in the context of software development.

Silicon Nanosheets: An Emerging 2D Photonic Material with a Large Transient Nonlinear Optical Response beyond Graphene

The present work reports on the transient nonlinear optical (NLO) responses of two different types of 2D silicon nanosheets (SiNSs), namely hydride-terminated silicon nanosheets (SiNS–H) and 1-dodecene-functionalized silicon nanosheets (SiNS–dodecene). The main motivation of this study was to extend the knowledge regarding the NLO properties of these Si–based materials, for which very few published studies exist so far. For that purpose, the NLO responses of SiNS–H and SiNS–dodecene were investigated experimentally in the nanosecond regime at 532 and 1064 nm using the Z-scan technique, while the obtained results were compared to those of certain recently studied graphene nanosheets. SiNS–dodecene was found to exhibit the largest third-order susceptibility χ(3) values at both excitation wavelengths, most probably ascribed to the presence of point defects, indicating the importance of chemical functionalization for the efficient enhancement and tailoring of the NLO properties of these emerging 2D Si-based materials. Most importantly, the results demonstrated that the present silicon nanosheets revealed comparable and even larger NLO responses than graphene nanosheets. Undoubtedly, SiNSs could be strong competitors of graphene for applications in 2D-material-based photonics and optoelectronics.

THE NAMES FOR SNIPE BIRD (GALLINAGO GALLINAGO) IN UDMURT DIALECTS

The article discusses the Udmurt dialect names of the snipe bird (Gallinago gallinago), which is from the snipe family of the Charadriiformes order. The main sources are field dialect materials of the Laboratory of Linguistic Mapping and Historical Lexicology of Udmurt State University, collected within the project “Dialectological Atlas of the Udmurt language”. In this paper methods of linguo-geographical description, structural-semantic and etymological analysis of words are used. Udmurt names for snipe appeared during the period of independent development of the language. In the Udmurt dialects, the most frequently recorded word is n'urtaka , formed from the n'urvyltaka form due to contraction. We believe that it is the most ancient name for the snipe. The main motivation used in the snipe nomination is a sound similar to the bleating of a ram, which is emitted by a displaying male snipe. Most of the lexical variants have a two-component structure formed from original and borrowed nouns. The first component is an attributive noune. It indicates the habitat / nesting place of the bird ( n'ur ‘marshy’, muvyr ‘terrestrial’), characterizes its nocturnal lifestyle ( uy ‘nocturnal’), expresses belonging to the wild nature ( lud , kyr ‘wild’) and the class Birds ( in' ‘heavenly’). The second component is the name of domestic animals ( taka ‘ram’, ketchtaka ‘goat’, kaza ‘she-goat’). Typological similarity of the snipe nomination processes is observed in some related and unrelated languages. Such coincidence of motivation and semantic structures of words is due to the biological characteristics of this bird.

Hobbes and the economic, social and cultural rights of the universal declaration of human rights

This article argues that the conceptions of natural rights in Hobbes’s theory and of economic, social and cultural rights in the Universal Declaration of Human Rights have three common features that serve to justify the thesis that a satisfactory order of coexistence cannot be achieved without extensive state power. Both conceptions identify rights with interests whose satisfaction is considered paramount. Both perspectives see the state as the shaper of the legal order that rights do not create. Finally, both see the state as the entity that must monopolize the management of individual interests represented in rights. This article suggests that these findings are paradoxical when confronted with the main motivation behind the drafting of the Declaration.

A Comparison of Women’s Motivations to Enter the Police Profession in the Caribbean

Absent from the criminological literature on policing in the Caribbean are studies on female’s motivations to become police officers, studies using female police recruits and studies using a comparative approach. As a result of this gap, data were gathered from female police recruits in Jamaica ( N = 37) and Trinidad and Tobago ( N = 60) in July 2017 via a standardised, self-administered questionnaire in order to determine their motivations for entry into policing. The main motivation for female’s entry into policing in both jurisdictions was job security. Revenge and the desire for power and authority were the least cited motivations for entry into the police profession in both jurisdictions. The importance of females as police officers, study limitations and directions for future research are also discussed.

Orbital Period Refinement of CoRoT Planets with TESS Observations

CoRoT was the first space mission dedicated to exoplanet detection. Operational between 2007 and 2012, this mission discovered 37 transiting planets, including CoRoT-7b, the first terrestrial exoplanet with a measured size. The precision of the published transit ephemeris of most of these planets has been limited by the relative short durations of the CoRoT pointings, which implied a danger that the transits will become unobservable within a few years due to the uncertainty of their future transit epochs. Ground-based follow-up observations of the majority of the CoRoT planets have been published in recent years. Between Dec. 2018 and Jan. 2021, the TESS mission in its sectors 6 and 33 re-observed those CoRoT fields that pointed towards the Galactic anti-center. These data permitted the identification of transits from nine of the CoRoT planets, and the derivation of precise new transit epochs. The main motivation of this study has been to derive precise new ephemerides of the CoRoT planets, in order to keep these planets’ transits observable for future generations of telescopes. The TESS data were analyzed for the presence of transits and the epochs of these re-observed transits were measured. The original CoRoT epochs, epochs from ground-based follow-up observations and those from TESS were collected. From these data, updated ephemerides are presented for nine transiting planets discovered by the CoRoT mission in its fields pointing towards the Galactic anti-center. In three cases (CoRoT-4b, 19b and 20b), transits that would have been lost for ground observations, due to the large uncertainty in the previous ephemeris, have been recovered. The updated ephemerides permit transit predictions with uncertainties of less than 30 min for observations at least until the year 2030. No significant transit timing variations were found in these systems.

Who Watches Cricket?

Vidya Subramaniam explores the spectacle of sports in all its dimensions. She interrogates the role of media, technology and market in recent times, through the continuing transformation of cricket into its current form as a hugely marketable, visible entertainment entity, or in other words, a spectacle. While the popular opinion is that this new version of cricket on television and the use of technology in so many aspects of the sport is in fact making for a larger knowledgeable spectators, the author argues the opposite. It may well be that the emphasis on the ‘entertainment quotient’ of the sport is attracting audiences that had started moving away from the sport and may not be knowledgeable about the game. More importantly, in keeping with the dominant thread in sports sociology that a sport can whip up a frenzy much like war, new formats of cricket such as the Indian Premier League are structured to showcase nationalism. The main motivation of large sections of those who follow IPL, the author argues, is country above all else and not a passion for the sport.

Preparation of Cast Metallic Foams with Irregular and Regular Inner Structure

The aim of this paper is to summarize the possibilities of foundry methods for the production of metallic foams. At present, there are a number of production technologies for this interesting material, to which increasing attention has been paid in recent years. What is unique about metallic foams is the combination of their physical and mechanical properties. As part of our research, we designed and verified four main methods of metallic foam production by the foundry technology, whose products are metallic foam castings with regular and irregular arrangements of internal cavities. All these methods use materials and processes commonly used in conventional foundry technologies. The main idea of the research is to highlight such technologies for the production of metallic foams that could be provided by manufacturing companies without the need to introduce changes in production. Moreover, foundry methods for the production of metallic foams have the unique advantage of being able to produce even complex shaped parts and can thus be competitive compared to today's established technologies, the output of which is usually only a semi-finished product for further processing. This fact was the main motivation for the research.