Autonomous maneuver strategy of swarm air combat based on DDPG

Unmanned aerial vehicles (UAVs) have been found significantly important in the air combats, where intelligent and swarms of UAVs will be able to tackle with the tasks of high complexity and dynamics. The key to empower the UAVs with such capability is the autonomous maneuver decision making. In this paper, an autonomous maneuver strategy of UAV swarms in beyond visual range air combat based on reinforcement learning is proposed. First, based on the process of air combat and the constraints of the swarm, the motion model of UAV and the multi-to-one air combat model are established. Second, a two-stage maneuver strategy based on air combat principles is designed which include inter-vehicle collaboration and target-vehicle confrontation. Then, a swarm air combat algorithm based on deep deterministic policy gradient strategy (DDPG) is proposed for online strategy training. Finally, the effectiveness of the proposed algorithm is validated by multi-scene simulations. The results show that the algorithm is suitable for UAV swarms of different scales.

Articulation of Facade Graphics and Techniques of its Implementation

The article deals with issues at the boundary of architecture and technology, related to visual articulation. The facade graphics is a relatively new phenomenon that has arisen over the last two decades. Some of the image implementation techniques it uses have been known for a long time. Some of them are derived from stained glass (e.g. the technique of manual enamel application), some are related to the already known techniques of workshop graphics (screen printing). One of the latest technological achievements is the development of digital printing technology. Each of the aforementioned techniques has specific artistic possibilities and means of expression, which influences the articulation of the image in the external partition and has a significant impact on a number of compositional aspects. The image placed in the façade supports the building's form, underlining its shape, emphasizing important places in the building. The work examines the relationship between the applied techniques of implementation and the properties of the image on glass. An important part is to determine to what extent the construction of the image and the applied plastic measures affect the visual range of the glass partition and the functional properties. Particularly interesting projects are those made with several techniques, and those in which a new technique was discovered, which is later copied in other projects. The research can make a strong case for using artistic glass in the facade of a building and provide guidance for designers and investors. The publication will present examples of implementations placed in the facade of the building. The phenomenon will be investigated on the basis of buildings constructed over the last two decades. Due to the global nature of plastic phenomena, there is no limited research territory.

Normative Performance Measurement in Simulated Air Combat

BACKGROUND: Normative performance (NP) describes the pilots adherence to tactics, techniques, and procedures (TTPs). Until now, there has not been a global NP measurement technique for beyond visual range (BVR) air combat, and the methodology and technology related to the evaluation of NP have fallen behind the pace of the overall technical progress of distributed mission operations (DMO) training.METHODS: Platform-independent core air combat tasks were identified. The execution of these tasks is directed with TTPs. BVR air combat missions were flown in a DMO simulator system and the design NP was varied between missions. Observers viewed debriefs of these missions and attempted to identify TTP-regulated air combat tasks. Once identified, they scored the pilots NP in those tasks. The scoring was based on the level of TTP adherence and the impact a nonadherence had on the mission accomplishment.RESULTS: All observers were able to identify most of the TTP-regulated air combat tasks. There was a strong positive correlation between the observed and design NP scores. The overall Kappa indicated a fair agreement between the observers. The percentage of observers NP assessments which agreed with the design NP varied from 49.60 to 85.28% in different air combat missions. On average, 73.9%6 of the observers NP scores agreed with the design NP scores.CONCLUSIONS: Observers were able to accurately identify TTP-regulated tasks and score NP of these tasks during an air combat debrief. There was a moderate agreement between the observers NP scores.Mansikka H, Virtanen K, Mkinen L, Harris D. Normative performance measurement in simulated air combat. Aerosp Med Hum Perform. 2021; 92(11):908-912.

The Image of Petrushka in Russian Children’s Books of the 1920s — Early 1930s

The image of Russian puppet theater’s main character, Petrushka, played an important role in the history of Russian culture and embodied some important features of the national character. His images are quite widely and variously represented on the pages of children’s books. At the beginning of the 20th century and in the first post-revolutionary years, publications about the adventures of Petrushka fulfilled an important mission: they recorded characteristic examples of folk art, preserved the memory of farcical performances, and supported the tradition of the art of “Petrushka makers”. The books served as manuals for novice puppeteers.In the 1920s — early 1930s, Petrushka continued to be one of the most popular characters of children’s books and aroused interest of many Russian writers and graphic artists. This indicates their desire to find a basis and support in the popular laughter culture, to continue its traditions, to bring elements of theatrical aesthetics into books.Using a complex of methods of book, art and source studies, the article aims to consider the transformation of the image of Petrushka in children’s books of the 1920s — early 1930s.The author draws attention to the significant differences between the literary component of such publications and their visual range. Writers, as a rule, sought to “re-educate” the areal joker and brawler, to ennoble his manners, modernize his appearance, and involve the popular character in solving actual ideological and pedagogical problems. Artists were more careful about the canonical, historically formed image of Petrushka, resisted too radical reinterpretation of it. Of particular interest in this regard are the illustrative cycles of I.S. Efimov, A.I. Sokolov-Asi, A.A. Radakov, V.M Konashevich, L.V. Popova, F.F. Kondratov.The best writers and artists of those years managed to preserve the most essential features of the character, breathe new life into him, save him from oblivion, from complete loss of identity, and pass him on to new generations of creators and readers of children’s books.

Impact of Windshield Optical Aberrations on Visual Range Camera Based Classification Tasks Performed by CNNs

Cameras operating in the visual range of the electromagnetic spectrum are central to advanced driver assistance systems (ADAS). Front cameras, analyzing traffic, are often located behind the windshield to detect and classify objects.Thus, the area of the windshield within the camera’s field of view is a part of the optical system. Simple windshields consist of two curved glass surfaces connected by a thermoplastic interlayer. Due to defects present in the raw glass, as well as those introduced during the bending and lamination process, windshields will have optical aberrations. While optical quality may be suitable for human vision, it can fall short of what is needed for machine vision. In this article we investigate how the optical aberrations generated by laminated safety glass (LSG) influence the optical performance of a camera system and based on this, how the classification of image content by a convolutional neural network (CNN) is affected. A method for wavefront measurements of LSG samples is presented, which allows us to parameterize a linear optical model in Zernike Space. From this, we derive space-variant point spread functions (PSFs) and apply those to the dataset to simulate the windshield’s impact on the camera image. As a use case, a CNN was trained on the unmodified dataset and compared to the modified versions with the LSG models applied. We measured and modelled two different LSG samples, one with high and the other one with low optical quality. We compare the prediction accuracy of the classification with the unmodified data. The highquality sample had negligible effect on the overall classification accuracy, while the low-quality sample lowered the prediction accuracy by up to ten percentage points due to the optical aberrations.

Mitochondria are specifically vulnerable to 420nm light in drosophila which undermines their function and is associated with reduced fly mobility

Increased blue light exposure has become a matter of concern as it has a range of detrimental effects, but the mechanisms remain unclear. Mitochondria absorb short wavelength light but have a specific absorbance at 420nm at the lower end of the human visual range. This 420nm absorption is probably due to the presence of porphyrin. We examine the impact of 420nm exposure on drosophila melanogaster mitochondria and its impact on fly mobility. Daily 15 mins exposures for a week significantly reduced mitochondrial complex activities and increased mitochondrial inner membrane permeability, which is a key metric of mitochondrial health. Adenosine triphosphate (ATP) levels were not significantly reduced and mobility was unchanged. There are multiple options for energy/time exposure combinations, but we then applied single 420nm exposure of 3h to increase the probability of an effect on ATP and mobility, and both were significantly reduced. ATP and mitochondrial membrane permeability recovered and over corrected at 72h post exposure. However, despite this, normal mobility did not return. Hence, the effect of short wavelengths on mitochondrial function is to reduce complex activity and increasing membrane permeability, but light exposure to reduce ATP and to translate into reduced mobility needs to be sustained.