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Predicting impact strength of perforated targets using artificial neural networks trained on FEM-generated datasets

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defence Technology（防务技术） 2024年第2期32卷 32-44页

作者： Nikita Kazarinov Aleksandr Khvorov saint Petersburg State University Saint Petersburg 199034Russia Higher School of Economics Saint Petersburg 190121Russia

The paper considers application of artificial neural networks(ANNs)for fast numerical evaluation of a residual impactor velocity for a family of perforated PMMA(Polymethylmethacrylate)targets.The ANN models were trained using sets of numerical results on impact of PMMA plates obtained via dynamic FEM coupled with incubation time fracture criterion.The developed approach makes it possible to evaluate the impact strength of a particular target configuration without complicated FEM calculations which require considerable computational resources.Moreover,it is shown that the ANN models are able to predict results for the configurations which cannot be processed using the developed FEM routine due to numerical instabilities and errors:the trained neural network uses information from successful computations to obtain results for the problematic cases.A simple static problem of a perforated plate deformation is discussed prior to the impact problem and preferable ANN architectures are presented for both problems.Some insight into the perforation pattern optimization using a genetic algorithm coupled with the ANN is also made and optimized perforation patterns which theoretically enhance the target impact strength are constructed.

关键词： Machine learning Impact Dynamic fracture FEM Mesh distortion Optimization

Influence of ambient water coloration on habitat and conspecific choice in the female Lake Malawi cichlid, Metriaclima zebra

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Current Zoology 2024年第2期70卷 214-224页

作者： Noori Choj Nicolas Mathevon Eileen A.Hebets Marilyn Beauchaud School of Biological Sciences University of Nebraska-LincolnLincolnNEUSA ENES Bioacoustics Research Laboratory CRNLCNRSInsermUniversite de Saint-EtienneSaint-EtienneFrance Max Planck Institute of Animal Behavior KonstanzGerman

Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments.These sen-sory system adaptations are hypothesized to have influenced the evolution of the diverse male nuptial coloration.In rock-dwelling Lake Malawi mbuna cichlids,however,the extent to which ambient light environments influence female sensory systems and potentially associated male nuptial coloration remains unknown.Yet,the ubiquitous blue flank coloration and UV reflection of male mbuna cichlids suggest the potential impacts of the blue-shifted ambient light environment on these cichlid's visual perception and male nuptial coloration in the shallow water depth in Lake Malawi.In the present study,we explored whether and how the sensory bias of females influences intersexual communication in the mbuna cichlid,Metriaclima zebra.A series of choice experiments in various light environments showed that M.zebra females (1)have a pref-erence for the blue-shifted light environment,(2)prefer to interact with males in blue-shifted light environments,(3)do not show a preference between dominant and subordinate males in full-spectrum,long-wavelength filtered,and short-wavelength filtered light environments,and (4)show a"reversed"preference for subordinate males in the UV-filtered light environment.These results suggest that the visual perception of M.zebra females may be biased to the ambient light spectra in their natural habitat by local adaptation and that this sensory bias may influence the evolution of blueand UV reflectivepatterns in male nuptial coloration.

关键词： ambient light environment Lake Malawi male coloration mbuna cichlids Metriaclima zebra sensory bias UV coloration UV perception visual communication.

On the effect of pitch and yaw angles in oblique impacts of smallcaliber projectiles

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defence Technology（防务技术） 2024年第1期31卷 73-94页

作者： Teresa Fras French-German Research Institute of saint-Louis(ISL) Saint-LouisFrance

A terminal ballistic analysis of the effects of 7.62 mm × 51 AP P80 rounds on inclined high-strength armor steel plates is the focus of the presented study.The findings of an instrumented ballistic testing combined with 3D advanced numerical simulations performed using the IMPETUS Afea? software yielded the conclusions.The experimental verification proved that slight differences in the pitch-andyaw angles of a projectile upon an impact caused different damage types to the projectile’s core.The residual velocities predicted numerically were close to the experimental values and the calculated core deviations were in satisfactory agreement with the experimental results.An extended matrix of the core deviation angles with combinations of pitch-and-yaw upon impact angles was subsequently built on the basis of the numerical study.The presented experimental and numerical investigation examined thoroughly the influence of the initial pitch and yaw angles on the after-perforation projectile’s performance.

关键词： Ballistic impact Small-caliber projectile Pitch and yaw impact angles Shadowgraphy IMPETUS Afea Numerical simulations

Strong Subgame Consistency of the Core in Stochastic Network Formation Games

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Journal of the Operations Research Society of China 2024年第1期12卷 189-213页

作者： Ping Sun Elena Parilina Faculty of Applied Mathematics and Control Processes Saint Petersburg State UniversitySaint Petersburg199034Russia

We consider a model of network formation as a stochastic game with random duration proposed initially in Sun and Parilina(Autom Remote Control 82(6):1065–1082,2021).In the model,the leader first suggests a joint project to other players,i.e.,the network connecting them.Second,the players are allowed to form fresh links with each other updating the initially proposed network.The stage payoff of any player is defined depending on the network structure.There are two types of randomness in the network formation process:(i)links may fail to be formed with different probabilities although players intend to establish them,(ii)the game process may terminate at any stage or transit to the next stage with a certain probability distribution.Finally,a network is formed as a result of players’decisions and realization of random variables.The cooperative version of the stochastic game is investigated.In particular,we examine the properties of subgame consistency as well as strong subgame consistency of the core.We provide a payment mechanism or regularization of the core elements to sustain its subgame consistency and avoid the player’s deviations from the cooperative trajectory.In addition,the distribution procedure of the core elements is regularized in case there are negative payments to achieve only nonnegative payments to the players at any stage.The sufficient condition of a strongly subgame consistent core is also obtained.We illustrate our theoretical results with a numerical example.

关键词： Stochastic game Network formation Core Strong subgame consistency

Opinion Dynamics in Two-Layer Networks with Hypocrisy

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Journal of the Operations Research Society of China 2024年第1期12卷 109-132页

作者： Chi Zhao Elena Parilina saint Petersburg State University Saint Petersburg199034Russia Qingdao University School of Mathematics and StatisticsQingdao 266071ShandongChina

We propose a general concealed voter model(GCVM),in which individuals interact in two layers and can exchange their opinions in the internal layer.This interaction is not allowed in a CVM.By exchanging opinions in the internal layer,we mean that individuals share their real or internal opinions with their close friends.The process of opinion formation in GCVM is presented in the paper.We make the series of numerical simulations of GCVM with different network structures(both external and internal)and get some counterintuitive conclusions.For instance,we find out that sometimes with a relatively simple network structure of an external layer the consensus within the individuals’opinions cannot be reached,and if individuals in the network are not good at expressing their opinions publicly(in an external layer),exchanging opinions with their close friends(in an internal layer)is almost useless.

关键词： Opinion dynamics Voter model Concealed voter model General concealed voter model

Exploring the effects of dietary inulin in rainbow trout fed a high‑starch,100%plant‑based diet

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Journal of Animal Science and Biotechnology 2024年第2期15卷 713-732页

作者： Raphaël defaix Jep Lokesh Laura Frohn Mickael Le Bechec Thierry Pigot Vincent Veron Anne Surget Sandra Biasutti Frederic Terrier Sandrine Skiba-Cassy Jerome Roy Stephane Panserat Karine Ricaud Universite de Pau Et des Pays de L’Adour E2S UPPAINRAENUMEASaint‑Pee‑Sur‑NivelleFrance Universite de Pau Et des Pays de L’Adour E2S UPPACNRSIMT Mines AlesIPREMPauFrance Universite de Pau Et des Pays de L’Adour E2S UPPAIUT des Pays de l’AdourDepartement Genie BiologiqueMont de MarsanFrance.

Background High dietary carbohydrates can spare protein in rainbow trout(Oncorhynchus mykiss)but may affect growth and health.Inulin,a prebiotic,could have nutritional and metabolic effects,along with anti-inflammatory properties in teleosts,improving growth and welfare.We tested this hypothesis in rainbow trout by feeding them a 100%plant-based diet,which is a viable alternative to fishmeal and fish oil in aquaculture feeds.In a two-factor design,we examined the impact of inulin(2%)as well as the variation in the carbohydrates(CHO)/plant protein ratio on rainbow trout.We assessed the influence of these factors on zootechnical parameters,plasma metabolites,gut microbiota,production of short-chain fatty acids and lactic acid,as well as the expression of free-fatty acid receptor genes in the mid-intestine,intermediary liver metabolism,and immune markers in a 12-week feeding trial.Results The use of 2%inulin did not significantly change the fish intestinal microbiota,but interestingly,the high CHO/protein ratio group showed a change in intestinal microbiota and in particular the beta diversity,with 21 bacterial genera affected,including Ralstonia,Bacillus,and 11 lactic-acid producing bacteria.There were higher levels of butyric,and valeric acid in groups fed with high CHO/protein diet but not with inulin.The high CHO/protein group showed a decrease in the expression of pro-inflammatory cytokines(il1b,il8,and tnfa)in liver and a lower expression of the genes coding for tight-junction proteins in mid-intestine(tjp1a and tjp3).However,the 2%inulin did not modify the expression of plasma immune markers.Finally,inulin induced a negative effect on rainbow trout growth performance irrespective of the dietary carbohydrates.Conclusions With a 100%plant-based diet,inclusion of high levels of carbohydrates could be a promising way for fish nutrition in aquaculture through a protein sparing effect whereas the supplementation of 2%inulin does not appear to improve the use of CHO when combined with a 100%plant-based diet.

关键词： Aquaculture Fish nutrition Gut microbiota Immune markers Intermediary metabolism Inulin Prebiotic Rainbow trout Short-chain fatty acids

A study on wildfire impacts on greenhouse gas emissions and regional air quality in South of Orléans,France

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Journal of Environmental Sciences 2024年第1期135卷 521-533页

作者： Chaoyang Xue Gisèle Krysztofiak Yangang Ren Min Cai Patrick Mercier Frédéric Le Fur Corinne Robin Benoit Grosselin Véronique Daele Max RMcGillen Yujing Mu Valéry Catoire Abdelwahid Mellouki Laboratoire de Physique et Chimie de l’Environnement et de l’Espace(LPC2E) CNRS–UniversitéOrléans–CNES(UMR 7328)Orléans Cedex 245071France Institut de Combustion AérothermiqueRéactivitéEnvironnement(ICARE)CNRSOrléans Cedex 245071France Research Centre for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Lig’Air-Association de surveillance de la qualitéde l’air en région Centre-Val de Loire Saint-Cyr-en-Val 45590France Mohammed V University RabatMorocco

Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS satellite.Based on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were characterized.Significant increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air quality.Emission factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous studies.Changes in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and discussed.Moreover,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission inventories.Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions.For instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant overestimation.Considering that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.

关键词： Wildfire Air quality Emission factor Emission inventory VOLTAIRE supersite

Incidental and secondary findings in trio exome sequencing

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Genes & Diseases 2024年第4期11卷 152-154页

作者： Camille Cohen Emeline Bellanger Jeremie Mortreux Laure Raymond Francois Vialard Rodolphe Dard department of Genetics Centre Hospitalier Intercommunal de Poissy-Saint-Germain-en-LayePoissy 78300France RHuMA UMR-BREEDINRA-ENVA-UVSQMontigny le Bretonneux 78180France Service de Genetique Laboratoire Eurofins BiomnisLyon 69007France

Exome sequencing(ES)generates secondary findings(SFs)in 2%of tested individuals if one follows the American College of Medical Genetics and Genomics(ACMG)guide-lines.i,z2 However,the rate of incidental and secondary findings(ISFs)is higher in routine clinical practice because of(i)the use of trio ES instead of solo sequencing and(i)the exclusion of the incidental findings(IFs)of medical value concerning genes in the ACMG list.Hence,it is not clear how sufficient is a restricted list of genes to detect every ISF of major clinical value;and what is the amount of additional workload for the laboratory.

关键词： routine clinical finding

Competitive Resource Allocation Among Urban Congestion Areas in a Modern Big City

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Journal of the Operations Research Society of China 2024年第1期12卷 133-153页

作者： Alexander Krylatov Anastasiya Raevskaya Institute of Applied Mathematical Research of the Karelian Research Centre of the Russian Academy of Sciences Petrozavodsk185910Russia saint Petersburg State University Saint Petersburg199034Russia

The continuing growth of modern big cities leads to their spatial expansion and the emergence of new road connections and urban areas.Areas where large transportation flows of pedestrians,passengers,and drivers come together create demand points,which attract business companies that strive to allocate their resources in the most sought-after places.However,the law of supply and demand restrains companies from allocating all their resources solely in the most popular congestion areas since the more valuable an urban area,the higher the cost to be paid for a resource unit allocation there.As a result,companies act in a non-cooperative manner and try to minimize their own overall costs when allocating resources across available commercial areas in a big city.Non-cooperative behavior of companies leads to the problem of Nash equilibrium search in the game of competing entrepreneurs.In this paper,we study the corresponding resource allocation game under affine cost functions and obtain Nash equilibrium strategies in explicit form.These findings allow us to develop a simple procedure for computing Nash equilibria in the game of companies allocating their resources among urban congestion areas.The computational study demonstrates the dependence of the average price for resource allocation on the number of players and their resource volumes.The outcome of the paper contributes to flow theory and seems to be fresh and useful for managers.

关键词： Resource allocation Nash equilibrium Affine costs