检索结果-南通市图书馆

CHARACTERISATION OF RATIONAL AND NURBS deVELOPABLE SURFACES IN COMPUTER AIdeD deSIGN

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2021年第4期39卷 556-573页

作者： Leonardo Fernandez-Jambrina ETSI Navales Universidad Politecnica de Madrid28040-MadridSpain

In this paper we provide a characterisation of rational developable surfaces in terms of the blossoms of the bounding curves and three rational functions∧,M,ν.Properties of developable surfaces are revised in this framework.In particular,a closed algebraic formula for the edge of regression of the surface is obtained in terms of the functions∧,M,ν,which are closely related to the ones that appear in the standard decomposition of the derivative of the parametrisation of one of the bounding curves in terms of the director vector of the rulings and its derivative.It is also shown that all rational developable surfaces can be described as the set of developable surfaces which can be constructed with a constant∧,M,ν.The results are readily extended to rational spline developable surfaces.

关键词： NURBS Bezier Rational Spline NURBS developable surfaces

Recent Advances on Early-Stage Fire-Warning Systems: Mechanism, Performance, and Perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第12期14卷 106-136页

作者： Xiaolu Li Antonio Vazquez-Lopez Jose Sanchez del Rio Saez de-Yi Wang IMdeA Materials Institute C/Eric Kandel228906 GetafeMadridSpain E.T.S.de Ingenieros de Caminos Universidad Politecnica de MadridCalle Profesor Aranguren 328040 MadridSpain departamento de Ingenieria Electrica Electronica Automatica y Fisica AplicadaETSIDIUniversidad Politecnica de MadridRonda de Valencia 328012 MadridSpain

Early-stage fire-warning systems(EFWSs)have attracted significant attention owing to their superiority in detecting fire situations occurring in the pre-combustion process.Substantial progress on EFWSs has been achieved recently,and they have presented a considerable possibility for more evacuation time to control constant unintentional fire hazards in our daily life.This review mainly makes a comprehensive summary of the current EFWSs,including the working mechanisms and their performance.According to the different working mechanisms,fire alarms can be classified into graphene oxide-based fire alarms,semiconductor-based fire alarms,thermoelectric-based fire alarms,and fire alarms on other working mechanisms.Finally,the challenge and prospect for EFWSs are briefly provided by comparing the art of state of fire alarms.This work can propose a more comprehensive understanding of EFWSs and a guideline for the cutting-edge development direction of EFWSs for readers.

关键词： Smart thermosensitive fire sensors Working mechanism Response time Signal conversion

Effect of intensity and duration of anthropic noises on European mink locomotor activity and fecal cortisol metabolite levels

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2022年第6期68卷 688-699页

作者： Lorena ORTIZ-JIMENEZ Carlos IGLESIAS-MERCHAN Alba Itzel MARTıNEZ-SALAZAR Isabel BARJA department of Biology Zoology UnitUniversidad Autonoma de MadridMadrid28049Spain department of Forest and Environmental Engineering and Management Universidad Politecnica de MadridMadridSpain Geographic Information Systems Laboratory Institute of BiologyUniversidad Nacional Autonoma de MexicoMexico CityMexico Biodiversity and Global Change Research Centre(CIBC-UAM) Universidad Autonoma de MadridMadridSpain

Human activities involving noise emission can affect wild animals.European mink was exposed to road noise and human voice playbacks to analyze how sound intensity level and duration of both noises altered the time that individuals were active and if their fecal cortisol metabolite(FCM)levels varied.A Hierarchical Analysis Cluster was performed to establish 2 mink groups with respect to both noise source type:short duration/low intensity(SL)and long duration/high intensity(LH).We performed general linear mixed models to evaluate the variation in locomotor activity duration(s)and FCM(nanogram per gram)levels,respectively.The results showed both road noise and human voices decreased locomotor activity duration in SL more sharply compared with LH,and human voices were the triggers that induced the most pronounced response to both exposure conditions.FCM(ng/g)levels increased in SL compared with LH during road noise while the opposite happened during human voices.Differences based on sex and age of individuals were observed.In conclusion,noise characteristics given by the sound type determined the variations in locomotor activity duration while noise exposure level determined the variations in FCM(ng/g)levels.Attention should be paid to noisy activities(e.g.,recreational activities for visitors in protected natural areas)and loud groups of people to conserve wildlife,especially noise sensitive species.

关键词： anthropic disturbances European mink fecal cortisol metabolites noise exposure locomotor activity behavioral response

Comparative transcriptomics reveals hidden issues in the plant response to arthropod herbivores

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2021年第2期63卷 312-326页

作者： M.Estrella Santamaria Alejandro Garcia Ana Amaiz Irene Rosa-Diaz Gara Romero-Hernandez Isabel Diaz Manuel Martinez Centro de Biotecnologia y Genomica de Plantas Instituto Nacional de Investigacion y Tecnologia Agraria y AlimentariaUniversidad Politecnica de MadridMadridSpain departamento de Biotecnologia-Biologia Vegetal Escuela Tecnica Superior de Ingenierfa AgronomicaAlimentaria y de BiosistemasUniversidad Politecnica de MadridMadridSpain

Plants experience different abiotic/biotic stresses,which trigger their molecular machinery to cope with them. Besides general mechanisms prompted by many stresses, specific mechanisms have been introduced to optimize the response to individual threats. However, these key mechanisms are difficult to identify. Here, we introduce an in-depth species-specific transcriptomic analysis and conduct an extensive meta-analysis of the responses to related species to gain more knowledge about plant responses. The spider mite Tetranychus urticae was used as the individual species, several arthropod herbivores as the related species for meta-analysis, and Arabidopsis thaliana plants as the common host. The analysis of the transcriptomic data showed typical common responses to herbivory, such as jasmonate signaling or glucosinolate biosynthesis. Also, a specific set of genes likely involved in the particularities of the Arabidopsis-spider mite interaction was discovered. The new findings have determined a prominent role in this interaction of the jasmonateinduced pathways leading to the biosynthesis of anthocyanins and tocopherols. Therefore, tandem individual/general transcriptomic profiling has been revealed as an effective method to identify novel relevant processes and specificities in the plant response to environmental stresses.

关键词： Arabidopsis thaliana arthropod herbivore comparative transcriptomics plant defense Tetranychus urticae

Skew-symmetric Elements in Nonlinear Involutions in Group Rings

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2015年第2期22卷 321-332页

作者： A.P. Raposo Escuela Universitaria de Arquitectura Tecnica Universidad Politecnica de Madrid Madrid Spain

Given an involution in a group G, it can be extended in various ways to an involution in the group ring RG, where R is a ring, not necessarily commutative. In this paper nonlinear extensions are considered and necessary and sufficient conditions are given on the group G, its involution, the ring R and the extension for the set of skew-symmetric elements to be commutative and for it to be anticommutative.

关键词： group ring involution skew-symmetric element

design and Robust Performance Evaluation of a Fractional Order PID Controller Applied to a DC Motor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2017年第2期4卷 304-314页

作者： J.Viola L.Angel J.M.Sebastian universidad Pontificia Bolivariana Universidad Politecnica de Madrid Centre for Automation and Robotics (CAR) UPM-CSIC

This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.

关键词： Factorial experimental design fractional-order PID controller robustness analysis SIMC PID controller

Towards Fully Secure 5G Ultra-Low Latency Communications: A Cost-Security Functions Analysis

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第1期74卷 855-880页

作者： Borja Bordel Ramón Alcarria Joaquin Chung Rajkumar Kettimuthu Tomás Robles Iván Armuelles Universidad Politecnica de Madrid MadridEspana Argonne National Laboratory LemontILUSA universidad de Panama PanamaPanama

Future components to enhance the basic,native security of 5G networks are either complex mechanisms whose impact in the requiring 5G communications are not considered,or lightweight solutions adapted to ultrareliable low-latency communications(URLLC)but whose security properties remain under discussion.Although different 5G network slices may have different requirements,in general,both visions seem to fall short at provisioning secure URLLC in the future.In this work we address this challenge,by introducing cost-security functions as a method to evaluate the performance and adequacy of most developed and employed non-native enhanced security mechanisms in 5G networks.We categorize those new security components into different groups according to their purpose and deployment scope.We propose to analyze them in the context of existing 5G architectures using two different approaches.First,using model checking techniques,we will evaluate the probability of an attacker to be successful against each security solution.Second,using analytical models,we will analyze the impact of these security mechanisms in terms of delay,throughput consumption,and reliability.Finally,we will combine both approaches using stochastic cost-security functions and the PRISM model checker to create a global picture.Our results are first evidence of how a 5G network that covers and strengthened all security areas through enhanced,dedicated non-native mechanisms could only guarantee secure URLLC with a probability of∼55%.

关键词： 5G networks security analysis secure low latency communications URLLC eMBBC

What is the most effective exercise protocol to improve cardiovascular fitness in overweight and obese subjects？

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2017年第4期6卷 454-461页

作者： Eliane Aparecida Castro Ana Belen Peinado Pedro Jose Benito MercedeS Galindo Marcela Gonzalez-Gross Rocio Cupeiro department of Health and Human Performance Faculty of Physical Activity and Sport Sciences Universidad Polit~cnica de Madrid Madrid 28040 Spain LFE Research Group Universidad PolitOcnica de Madrid Madrid 28040 Spain Faculty of Physical Activity and Sport Sciences Universidad Politecnica de Madrid Madrid 28040 Spain ImFINE Research Group Universidad PolitOcnica de Madrid Madrid 28040 Spain

Background: Increased peak oxygen consumption(VO2 peak) can reduce cardiovascular risks associated with obesity. Our aim was to analyze the effect of a weight loss program on cardiovascular fitness in overweight(W) and obese(O) subjects.Methods: One hundred and sixty-seven subjects(77 males and 90 females), aged 18–50 years, performed a modified Bruce protocol before(pre)and after(post) a weight loss program of 24 weeks. This program combined physical training(strength, S; endurance, E; combined strength + endurance, SE; or physical activity recommendation, PA) 3 times per week, with a 25%–30% caloric restriction diet.Results: VO2 peak improved in overweight and obese males(pre and post values in L/min, respectively; W = 3.2 ± 0.6 vs. 3.7 ± 0.5, p < 0.001;O = 3.6 ± 0.6 vs. 3.8 ± 0.6, p = 0.013) as well as in overweight females(2.0 ± 0.3 vs. 2.3 ± 0.4, p < 0.001). VO2 peak in the first ventilatory threshold(VT1) increased for all 4 interventions in males(p < 0.05), except for S in the obese group(1.6 ± 0.2 vs. 1.7 ± 0.3, p = 0.141). In females, it increased in E(0.9 ± 0.2 vs. 1.4 ± 0.3, p < 0.001), SE(0.9 ± 0.2 vs. 1.2 ± 0.4, p = 0.003), and PA(0.9 ± 0.1 vs. 1.2 ± 0.2, p = 0.006) in overweight groups. Time-to-exhaustion improved in all subjects except for females in PA group(15.7 ± 0.3 min vs. 15.9 ± 0.3 min, p = 0.495).Conclusion: Our results suggest that all methods, including the recommendation of physical activity, can improve cardiovascular fitness in overweight subjects and obese males.

关键词： Combined training Endurance training Obesity Oxygen consumption Physical activity Strength training Ventilatory threshold

A catalog of gliadin alleles:Polymorphism of 20th-century common wheat germplasm

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2018年第6期6卷 628-641页

作者： Eugene Metakovsky Viktor Melnik Marta Rodriguez-Quijano Vladimir Upelniek Jose Maria Carrillo Unidad de Genetica Universidad Politecnica de MadridMadridSpain Vavilov Institute of General Genetics Russian Academy of Sciences MoscowRussia

A new, improved version of the catalog of 182 alleles at the six Gli loci of common wheat(T.aestivum L.) shown in electrophoregrams of 128 standard genotypes was used for analysis of1060 cultivars and lines bred in the 20 th century. The most frequent alleles in the studied germplasm occurred with frequencies of 18%–40%, with 30 unique alleles, one in each cultivar. Extremely high genetic diversity was found(average H for the six main Gli loci was0.870 ± 0.046), nearly identical in winter(H = 0.831) and spring(H = 0.856) wheats but differing among 28 groups of cultivars released in 22 countries. Each country or region was characterized by its own specific set of the most frequent Gli alleles, and the 28 cultivar groups formed five main relationship clusters if polymorphism at the six Gli loci was considered. However, different levels of similarity between groups of cultivars were found if polymorphism of the A, B, or D genomes of common wheat was tested separately. In general, the 20 th century germplasm of common wheat was differentiated and structured by country or region and cultivar type(spring or winter). Each elemental genome(in particular, A and D) contributed to the structure of the polymorphism studied. We propose that the structure of the wheat germplasm was a result of natural selection under the ecoclimatic conditions of cultivation specific to each country or region. As many as 27.4% of cultivars studied violated the requirement of the DUS rules for uniformity, being represented by mixtures of two or more closely related genotypes. However, the composition of a cultivar as a set of related but different genotypes may contribute to its adaptivity, and thereby to the known high plasticity of common wheat.

关键词： Gliadin alleles Genetic variation Gene geography Intra-varietal non-uniformity Allopolyploid Triticum aestivum