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Multi-planet extrasolar systems-detection and dynamics

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Research in Astronomy and Astrophysics 2012年第8期12卷 1044-1080页

作者： cristian Beaug Sylvio Ferraz-Mello Tatiana A.Michtchenko Instituto de Astronomía Teóricay Experimental Observatório Astronómico de CórdobaUniversidad de CórdobaArgentina Instituto de Astronomia Geofísica e Cie ncias AtmosfricasUniversidade de So PauloBrasil

20 years after the discovery of the first planets outside our solar system, the current exoplanetary population includes more than 700 confirmed planets around main sequence stars. Approximately 50% belong to multiple-planet systems in very diverse dynamical configurations, from two-planet hierarchical systems to multiple resonances that could only have been attained as the consequence of a smooth large- scale orbital migration. The first part of this paper reviews the main detection tech- niques employed for the detection and orbital characterization of multiple-planet sys- tems, from the （now） classical radial velocity （RV） method to the use of transit time variations （TTV） for the identification of additional planetary bodies orbiting the same star. In the second part we discuss the dynamical evolution of multi-planet systems due to their mutual gravitational interactions. We analyze possible modes of motion for hi- erarchical, secular or resonant configurations, and what stability criteria can be defined in each case. In some cases, the dynamics can be well approximated by simple ana- lytical expressions for the Hamiltonian function, while other configurations can only be studied with semi-analytical or numerical tools. In particular, we show how mean- motion resonances can generate complex structures in the phase space where different libration islands and circulation domains are separated by chaotic layers. In all cases we use real exoplanetary systems as working examples.

关键词： planetary systems -- planetary systems: formation

Optimal Feeder Routing in Urban Distribution Networks Planning with Layout Constraints and Losses

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Journal of Modern Power Systems and Clean Energy 2020年第5期8卷 1005-1014页

作者： Alessandro Bosisio Alberto Berizzi Edoardo Amaldi cristian Bovo Xu Andy Sun IEEE Department of Energy Politecnico di MilanoVia La Masa3420165 MilanoItaly Department of Electronics Informationand BioengineeringPolitecnico di MilanoVia Ponzio34/520133 MilanoItaly H.Milton Stewart School Georgia Institute of Technology775 Ferst DriveAtlanta GA 30332USA

We address the problem of optimally re-routing the feeders of urban distribution network in Milano,Italy,which presents some peculiarities and significant design *** has two separate medium-voltage(MV)distribution networks,previously operated by two different utilities,which grew up independently and *** results in a system layout which is inefficient,redundant,and difficult to manage due to different operating *** current utility UNARETI,which is in charge of the overall distribution system,aims at optimally integrating the two MV distribution networks and moving to a new specific layout that offers advantages from the perspectives of reliability and *** present a mixed-integer programming(MIP)approach for the design of a new network configuration satisfying the so-called 2-step ladder layout required by the *** model accounts for the main electrical constraints such as power flow equations,thermal limits of high-voltage(HV)/MV substation transformers,line thermal limits,and the maximum number of customers per *** power losses are taken into account via a quadratic formulation and a piecewise linear *** tests on a small-scale system and on a part of the Milano distribution network are reported.

关键词： Mixed-integer programming(MIP) graph theory power system planning urban distribution network feeder routing optimization

A comparative study for the performance of encased granular columns

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第2期11卷 379-388页

作者： Iman Hosseinpour cristian Soriano Marcio S.S.Almeida Department of Civil Engineering Faculty of EngineeringThe University of Guilan Graduate School in Research and Engineering (COPPE) Federal University of Rio de Janeiro (UFRJ)

This paper describes a three-dimensional(3D) numerical analysis of a test embankment on geotextileencased columns(GECs), in comparison with two-dimensional(2D) axisymmetric and plane strain analyses. The 3D numerical analysis was performed considering a rectangular strip under the embankment centerline. The 2D analysis was also carried out using axisymmetric unit cell and plane strain *** results indicated that the adopted 3D strip model represented well the measured deformations and pore pressure evolution during embankment construction and post-contraction *** the unit cell model, both plane strain and 3D analyses could properly determine the settlement profile along the embankment base as well as the profile of the horizontal soil deformation beneath the embankment toes. The plane strain analysis, however, was not able to compute the geotextile ring force which might be simply calculated using the axisymmetric unit cell approach. The paper also showed that, due to horizontal boundary fixities applied to the embankment borders, the unit cell model clearly underestimated the tension developed in the basal geogrid.

关键词： Soft soil Embankment Encased columns Geosynthetic Numerical analysis

Hidden Markov Models:Inverse Filtering,Belief Estimation and Privacy Protection

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Journal of Systems Science & Complexity 2021年第5期34卷 1801-1820页

作者： LOURENCO Ines MATTILA Robert ROJAS cristian R. HU Xiaoming WAHLBERG Bo Division of Decision and Control Systems School of Electrical Engineering and Computer ScienceKTH Royal Institute of TechnologyStockholmSweden Division of Optimizations and Systems Theory School of Engineering SciencesKTH Royal Institute of TechnologyStockholmSweden

A hidden Markov model(HMM)comprises a state with Markovian dynamics that can only be observed via noisy *** paper considers three problems connected to HMMs,namely,inverse filtering,belief estimation from actions,and privacy enforcement in such a ***,the authors discuss how HMM parameters and sensor measurements can be reconstructed from posterior distributions of an HMM ***,the authors consider a rational decision-maker that forms a private belief(posterior distribution)on the state of the world by filtering private *** authors show how to estimate such posterior distributions from observed optimal actions taken by the *** the setting of adversarial systems,the authors finally show how the decision-maker can protect its private belief by confusing the adversary using slightly sub-optimal *** range from financial portfolio investments to life science decision systems.

关键词： Belief estimation counter-adversarial systems hidden Markov models inverse decision making inverse filtering

Actin levels fluctuate in the seminiferous epithelium at various stages during spermatogenesis in the rat

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BIOCELL 2017年第2期41卷 63-65页

作者： cristian ACOSTA MABEL FOSCOLO JUAN CARLOS CAVICCHIA Instituto de Histología y Embriología de Mendoza(IHEM)-CONICET Universidad Nacional de Cuyo5500MendozaArgentina

The testis is a double gland comprised of the sperm-producing seminiferous tubules and a complex endocrine *** former structures generate and release whole cells(exocrine aspect of the gland)while the latter synthesize and release androgens and related *** testis also has poorly understood paracrine *** connexions play an important role during spermatogenesis.A key molecule within these structures is β-***,the present study aims at examining the expression pattern of β-actin during the various stages of the spermatic cycle in the *** achieve this goal,we used a combination of trans-illumination assisted microdissection of seminiferous tubules,confocal immunofluorescence and Western blot *** experiments revealed that the levels of β-actin fluctuate significantly during spermatogenesis,peaking immediately after spermiation.

关键词： Beta actin Seminiferous epithelium Trans-illumination assisted microdissection

Maintaining flexibility in smart grid consumption through deep learning and deep reinforcement learning

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Energy and AI 2023年第3期13卷 137-148页

作者： Fernando Gallego cristian Martin Manuel Diaz Daniel Garrido ITIS Software Institute University of MalagaMalagaSpain

The smart grid concept is key to the energy revolution that has been taking place in recent *** Grids have been present in energy research since their ***,the scarcity of data from different energy sources,hardware power,or co-simulation environments has hindered their *** advances in multi-agent-based systems,the possibility of simulating the behavior of different energy sources,combining real building consumption,and simulated data,storage batteries and vehicle charging points,has opened *** development has resulted in much research published using both simulated and physical *** these investigations show that the main problem is that the machine learning algorithms do not fully match the real behavior,it is complex to use them to replicate the different actions to be *** paper aims to combine the approach of behavior prediction with state-of-the-art techniques,such as deep learning and deep reinforcement learning,to simulate unknown or critical system scenarios.A very important element in smart grids is the possibility of maintaining consumption within specific ranges(flexibility).For this purpose,we have made use of Tensorflow libraries that predict energy consumption and deep reinforcement learning to select the optimal actions to be performed in our *** developed platform is flexible enough to include new technologies such as smart batteries,electric vehicles,etc.,and it is oriented to real-time operation,being applied in an on-going real project such as the European ebalance-plus project.

关键词： Multi-agent based system Smart grid Distributed energy resources

Antibacterial and Antioxidant Activities of ZnO Nanoparticles Synthesized Using Extracts of Allium sativum,Rosmarinus officinalis and Ocimum basilicum

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Acta Metallurgica Sinica(English Letters) 2016年第3期29卷 228-236页

作者： Manuela Stan Adriana Popa Dana Toloman Teofil-Danut Silipas Dan cristian Vodnar National Institute for Research and Development of Isotopic and Molecular Technologies 67-103 Donat 400293Cluj-Napoca Romania Department of Food Science and Technology University of Agricultural Sciences and Veterinary Medicine 3-5 ManasturStreet 400372 Cluj-Napoca Romania

ZnO nanoparticles（ZnO NPs） were synthesized by chemical method（coprecipitation） and biological method using aqueous extracts of garlic（Allium sativum）,rosemary（Rosmarinus officinalis） and basil（Ocimum basilicum）.The influence of plant extract on the antibacterial and antioxidant activities of green synthesized nanoparticles was *** X-ray diffraction studies reveal that all ZnO samples have hexagonal wurtzite *** particle size of ZnO NPs estimated by transmission electron microscopy analysis（between 14 and 27 nm） varies depending on the synthesis method of nanoparticles and the type of extracts from the plants *** functional groups involved in the biosynthetic procedure were evidenced by Fourier transform infrared *** presence of Mn^（2＋）ions,Zn vacancy complexes and oxygen vacancies in ZnO samples was highlighted by electron paramagnetic resonance *** green synthesized ZnO NPs have shown a good bactericidal activity against Staphylococcus aureus,Bacillus subtilis,Listeria monocytogenes,Escherichia coli,Salmonella typhimurium and Pseudomonas aeruginosa bacterial *** NPs synthesized using extracts of the selected plant species have been found to exhibit more enhanced antibacterial and antioxidant activities as compared to chemical ZnO NPs.

关键词： Zinc oxide nanoparticles Antioxidant activity Antibacterial activity Green synthesis Plant extracts

A longitudinal network analysis of social dynamics in rooks corvus frugilegus： repeated group modifications do not affect social network in captive rooks

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Current Zoology 2017年第5期63卷 379-388页

作者： Palmyre H. BOUCHERIE Sebastian SOSA cristian PASQUARETTA Valerie DUFOUR Institut Pluridisciplinaire Hubert Curien University of Strasbourg 23 rue Becquerel 67087 Strasbourg France Centre National de la Recherche Scientifique UMR 7178 67087 Strasbourg France Formerly affiliated with Grupo de Conducta Adaptativa e Interacci6n Psychology Faculty University of Barcelona 08035 Barcelona Spain

Numerous studies have investigated the remarkable variation of social features and the resulting structures across species. Indeed, relationships are dynamic and vary in time according to various factors such as environmental conditions or individuals attributes. However, few studies have investigated the processes that stabilize the structures within a given species, and the behavioral mechanisms that ensure their coherence and continuity across time. Here, we used a dynamic actor-based model, RSiena, to investigate the consistency of the temporal dynamic of relationships of a group of captive rooks facing recurrent modifications in group composition （i.e., the loss and introduction of individuals）. We found that changes in relationships （i.e., formation and removal） followed consistent patterns regardless of group composition and sex-ratio. Rooks preferentially interacted with paired congeners （i.e., unpopular attachment） and were more likely to form rela- tionships with individuals bonded to a current social partner （i.e., ＂friends of friends＂, or triadic closure）. The sex of individuals had no effect on the dynamic of relationships. This robust behav- ioral mechanisms formed the basis of inter-connected networks, composed of sub-structures of in- dividuals emerging from the enmeshment of dyadic and triadic motifs. Overall, the present study reveals crucial aspects of the behavioral mechanisms shaping rooks social structure, suggesting that rooks live in a well-integrated society, going far beyond the unique monogamous pair-bond.

关键词： corvids preferential attachment social interactions social network analysis temporal dynamics triadic closure.

A Comparative Analysis of Binary Logistic Regression and Analytical Hierarchy Process for Landslide Susceptibility Assessment in the Dobrovǎt River Basin,Romania

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Pedosphere 2016年第3期26卷 335-350页

作者： cristian V.PATRICHE Radu PIRNAU Adrian GROZAVU Bogdan ROSCA Romanian Academy Department of IasiGeography Group "Alexandru Ioan Cuza" University of Iasi Faculty of Geography

A correct assessment of the landslide susceptibility component is extremely useful for the diminution of associated potential risks to local economic development, particularly in regard to land use planning and soil conservation. The purpose of the present study was to compare the usefulness of two methods, i.e., binary logistic regression(BLR) and analytical hierarchy process(AHP), for the assessment of landslide susceptibility over a 130-km^2 area in the Moldavian Plateau(eastern Romania) region, where landslides affect large areas and render them unsuitable for agriculture. A large scale inventory mapping of all types of landslides(covering 13.7% of the total area) was performed using orthophoto images, topographical maps, and field surveys. A geographic information system database was created, comprising the nine potential factors considered as most relevant for the landsliding process. Five factors(altitude, slope angle, slope aspect, surface lithology, and land use) were further selected for analysis through the application of a tolerance test and the stepwise filtering procedure of BLR. For each predictor, a corresponding raster layer was built and a dense grid of equally spaced points was generated, with an approximately equal number of points inside and outside the landslide area, in order to extract the values of the predictors from raster layers. Approximately half of the total number of points was used for model computation, while the other half was used for validation. Analytical hierarchy process was employed to derive factor weights, with several pair-wise comparison matrices being tested for this purpose. The class weights, on a scale of 0 to 1, were taken as normalized landslide densities. A comparison of results achieved through these two approaches showed that BLR was better suited for mapping landslide susceptibility, with 82.8% of the landslide area falling into the high and very high susceptibility classes. The susceptibility class separation u

关键词： Moldavian Plateau multivariate statistical method predictor weights receiver operating characteristic curve semiqualitative method