Evolutionary and Observational Consequences of Dyson Sphere Feedback

The search for signs of extraterrestrial technology, or technosignatures, includes the search for objects which collect starlight for some technological use, such as those composing a Dyson sphere. These searches typically account for a star’s light and some blackbody temperature for the surrounding structure. However, such a structure inevitably returns some light back to the surface of its star, either from direct reflection or thermal reemission. In this work, we explore how this feedback may affect the structure and evolution of stars, and when such feedback may affect observations. We find that in general this returned light can cause stars to expand and cool. Our MESA models show that this energy is only transported toward a star’s core effectively by convection, so low-mass stars are strongly affected, while higher-mass stars with radiative exteriors are not. Ultimately, the effect only has significant observational consequences for spheres with very high temperatures (much higher than the often assumed ∼300 K) and/or high specular reflectivity. Lastly, we produce color–magnitude diagrams of combined star–Dyson sphere systems for a wide array of possible configurations.

Search Strategy for Buried Objects in Water: Geophysics, Probes and Dogs

The aqueous search for objects covered by sediment is a common and challenging problem. Here we outline a sequential methodology for the assessment of targets identified by sub-bottom profiling. This comprises desktop study of available data; background hydrological information gathering (bathymetry, sediment cover, water chemistry); acoustic sub-bottom imaging (water-penetrating radar, sonar); geolocation and probing of sub-bottom anomalies; and deployment of suitable scent dogs. This procedure creates a hierarchy of targets for examination by dive teams and thence recovery.

Differential Eye Movements in Verbal and Nonverbal Search

In addition to “nonverbal search” for objects, modern life also necessitates “verbal search” for written words in variable configurations. We know less about how we locate words in novel spatial arrangements, as occurs on websites and menus, than when words are located in passages. In this study we leveraged eye tracking technology to examine the hypothesis that objects are simultaneously screened in parallel while words can only be found when each are directly foveated in serial fashion. Participants were provided with a cue (e.g. rabbit) and tasked with finding a thematically-related target (e.g. carrot) embedded within an array including a dozen distractors. The cues and arrays were comprised of object pictures on nonverbal trials, and of written words on verbal trials. In keeping with the well-established “picture superiority effect,” picture targets were identified more rapidly than word targets. Eye movement analysis showed that picture superiority was promoted by parallel viewing of objects, while words were viewed serially. Different factors influenced performance in each stimulus modality; lexical characteristics such as word frequency modulated viewing times during verbal search, while taxonomic category affected viewing times during nonverbal search. In addition to within-platform task conditions, performance was examined in cross-platform conditions where picture cues were followed by word arrays, and vice versa. Although taxonomically-related words did not capture gaze on verbal trials, they were viewed disproportionately when preceded by cross-platform picture cues. Our findings suggest that verbal and nonverbal search are associated with qualitatively different search strategies and forms of distraction, and cross-platform search incorporates characteristics of both.

Strategic management of Ukraine's competitive position in the world wheat market in the context of covid-19 and active marketing

Based on the strategic analysis of Ukraine's competitive position in the world wheat market, a comprehensive assessment of this market was carried out in the context of COVID-19 and active marketing. The competitive strategies of the main participants are studied, the directions for strengthening the position of Ukraine are substantiated, strategic alternatives for the behavior of domestic subjects of the world wheat market are developed, the implementation of which will allow forming long-term stable competitive advantages. Proposals to strengthen Ukraine's competitive position in the world wheat market are substantiated, in particular: development of territorially new markets; increasing market share; formation of new market segments by improving the quality of grain and deepening its processing. These measures are recommended to be implemented within the aggressive marketing strategy of the leader, which involves the search for objects in the market for the acquisition and decentralization of management.

Task-Dependent Warping of Semantic Representations During Search for Visual Action Categories

Object and action perception in cluttered dynamic natural scenes relies on efficient allocation of limited brain resources to prioritize the attended targets over distractors. It has been suggested that during visual search for objects, distributed semantic representation of hundreds of object categories is warped to expand the representation of targets. Yet, little is known about whether and where in the brain visual search for action categories modulates semantic representations. To address this fundamental question, we studied human brain activity recorded via functional magnetic resonance imaging while subjects viewed natural movies and searched for either communication or locomotion actions. We find that attention directed to action categories elicits tuning shifts that warp semantic representations broadly across neocortex, and that these shifts interact with intrinsic selectivity of cortical voxels for target actions. These results suggest that attention serves to facilitate task performance during social interactions by dynamically shifting semantic selectivity towards target actions, and that tuning shifts are a general feature of conceptual representations in the brain.

Caudal Prefrontal Cortex

The caudal prefrontal (PF) cortex supports the visual search for objects such as foods both through eye movements and covert attention, and its connections explain how it can do this. The caudal PF cortex, which includes the frontal eye field, has connections with both the dorsal and ventral visual streams. The direction of eye movements depends on its connections with the superior colliculus and oculomotor nuclei. Covert attention depends on enhanced sensory responses that are mediated through top-down interactions with posterior sensory areas. Along with the granular parts of the orbital PF cortex, the caudal PF cortex evolved in early primates. Together, these two new areas led to improvements in searching for and evaluating objects that are hidden in a cluttered environment.

Searching surveillance video contents using convolutional neural network

Manual video inspection, searching, and analyzing is exhausting and inefficient. This paper presents an intelligent system to search surveillance video contents using deep learning. The proposed system reduced the amount of work that is needed to perform video searching and improved the speed and accuracy. A pre-trained VGG-16 CNNs model is used for dataset training. In addition, key frames of videos were extracted in order to save space, reduce the amount of work, and reduce the execution time. The extracted key frames were processed using the sobel operator edge detector and the max-pooling in order to eliminate redundancy. This increases compaction and avoids similarities between extracted frames. A text file, that contains key frame index, time of occurrence, and the classification of the VGG-16 model, is produced. The text file enables humans to easily search for objects of interest. VIRAT and IVY LAB datasets were used in the experiments. In addition, 128 different classes were identified in the datasets. The classes represent important objects for surveillance systems. However, users can identify other classes and utilize the proposed methodology. Experiments and evaluation showed that the proposed system outperformed existing methods in an order of magnitude. The system achieved the best results in speed while providing a high accuracy in classification.

HISTORICAL MAPS IN GIS: SCIENTIFIC AND METHODOLOGICAL ASPECT (MOLOCHNA GERMAN SETTLEMENT MAPS AS EXAMPLE)

Summary. In Ukrainian schools and high schools very little attention is paid to the methodological components of Geoinformatics and teaching methods using historical maps in GIS (geographic information systems). The purpose of the research is to show how GIS can be used in teaching local history. The research methodology is based on the principles of historicism, system-formation, scientific character, verification, the author’s objectivity, moderated narrative constructivism, and the use of general scientific and specially-historical methods. The scientific novelty of the article consists in the creation and use of information maps in GIS with regard to the history of Germans and Mennonites of the Zaporizhzhia oblast, as a basic cartographic material for training courses in local history. Such maps show the territory of Southern Ukraine in relation to various ethnic groups and faiths. In particular, Mennonites and ethnic Germans, who made a huge contribution to the cultural and economic development of the region and left a significant layer of cultural heritage. The maps findings presented in this article are parts of a large database of historical sources, and have already partially become the basis of such courses of local history as "History of the Zaporizhzhia oblast", "Historical Local History" at Melitopol State Pedagogical University. With the help of GIS maps, various primary historical sources (statistical, cartographic, etc.) come to the forefront and allow the study of local territorial units. The article will demonstrate the GIS maps of 27 German settlements of Molochna German settlements (Prishibskaya volost) for a certain time period. Conclusions. The use of historical GIS technologies contributes to the formation of such students’ skills as read the information on the historical maps; search for objects or information by given parameters, for example, by name; carry out calculations on digital maps; to form the spatial thinking of students, demonstrating the historical objects in three dimensions; create digital maps by own, especially based on the results of student observations.