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    Tytuł:
    Passive-active noise control of an acoustic duct
    Pasywno-aktywne metody kontroli hałasu w przewodzie akustycznym
    Autorzy:
    Tiseo, B.
    Concilio, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/281856.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    acoustic structural control
    damping noise control
    feedback
    Opis:
    In the recent years, noise control has become a significant factor in the design of automotive and aircraft industries. In general, methods of the passive noise control are practical and most effective at mid and high frequencies. On the other hand, active noise control techniques are more efficient at the low frequency range. Combined solutions seem to be the most appropriate key to cover the whole frequency range of frequencies. In the present study, a description of simulations for both feedback structural and acoustical structural control strategies are illustrated in order to maximize the damping within an acoustic duct by applying a passive foam layer bonded to an “active” surface.
    W ostatnich latach problem sterowania poziomem hałasu stał się szczególnie znaczący w projektowaniu na potrzeby przemysłu samochodowego i lotniczego. Jako ogólną zasadę można przyjąć, że pasywne metody redukcji hałasu są efektywne dla średnich i wysokich częstości dźwięku, podczas gdy metody aktywne dobrze się sprawdzają dla częstości niskich. Rozwiązanie oparte na kombinacji tych metod stanowi naturalny i najbardziej skuteczny sposób ograniczania hałasu w całym przedziale częstości. W pracy przedstawiono opis strategii sterowania poziomem hałasu bazującym na strukturalnym i akustycznym sprzężeniu zwrotnym, celującym w maksymalizację tłumienia wewnątrz przewodu akustycznego, na którego „aktywną” powierzchnię naniesiono warstwę pasywnej pianki.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2011, 49, 4; 1135-1149
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sound Transmission Through a Thin Plate with Shaped Frequency Response
    Autorzy:
    Wrona, Stanislaw
    Mazur, Krzysztof
    Rzepecki, Jaroslaw
    Chraponska, Anna
    Pawelczyk, Marek
    Powiązania:
    https://bibliotekanauki.pl/articles/177996.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    structural control
    frequency response shaping
    vibrating plate
    optimisation
    modelling
    Opis:
    Thin plates, in the form of individual panels or whole device casings, often separate the noise source from its recipients. It would be very desirable if the panels could effectively block the sound transmission preventing noise from further propagation. This is especially challenging to achieve at low frequencies. A promising approach, intensively developed in the recent years, is to employ active control methods by adding sensors and actuators, and running a control algorithm. However, if the noise is narrow-band, an alternative passive solution originally developed by the authors can be applied. It is based on appropriately located passive elements which can be used to alter the frequency response of the vibrating structure thus improving its sound insulation properties. Such an approach is referred to as the frequency response shaping method. The purpose of this paper is to further develop this method and apply it to a device casing panel. The efficiency of the method is evaluated by simulation and real experiments. Appropriate cost functions and mathematical models are formulated and used to optimise the arrangement of passive elements mounted to the plate, enhancing its sound insulation properties at the given frequency range. The results are reported, and advantages and limits of the method are pointed out and discussed.
    Źródło:
    Archives of Acoustics; 2019, 44, 4; 731-738
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dynamic behavior of steel frames with tuned mass dampers
    Autorzy:
    Jouneghani, K. T.
    Hosseini, M.
    Rohanimanesh, M. S.
    Dehkordi, M. R.
    Powiązania:
    https://bibliotekanauki.pl/articles/103041.pdf
    Data publikacji:
    2017
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Mechaników Polskich
    Tematy:
    earthquake
    Tuned Mass Dampers
    vibration control
    dynamic behaviour
    steel frames
    structural control
    Opis:
    In this paper, the application of tuned mass damper in improving the response of structures is considered. At first, three frames of 3, 9 and 20 stories are evaluated in which time history analysis is done according to El – Straw earthquake. The maximum reduction of among the three mentioned frames belongs to a 20-stories structure in which the rate of story displacement reduction is between 25 to 45%, and this indicates that by increasing the height of the structure, the performance of tuned mass damper improved. In the second part, the effect of semi-active tuned mass damper is studied on a 10-stories frame. Studies showed that using a tuned mass damper system with viscous damper with controller force decreases the average of maximum displacement of roof story down to 39.9 % and this amount of reduction is 22.8% for semi-active tuned mass damper. Finally, the performance of tuned Single and multiple mass Damper is evaluated on a 20-stories frame, and the results show that single and multiple dampers decrease structures ‘responses and the performance of tuned multiple dampers depends on the mass and frequency ratio and also concluded that the performance of tuned multiple mass dampers is reduced by transition to middle of the structure stories.
    Źródło:
    Advances in Science and Technology. Research Journal; 2017, 11, 2; 146-158
    2299-8624
    Pojawia się w:
    Advances in Science and Technology. Research Journal
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The use of synthesis methods in position optimisation and selection of tuned mass damper (TMD) parameters for systems with many degrees of freedom
    Autorzy:
    Dymarek, Andrzej
    Dzitowski, Tomasz
    Powiązania:
    https://bibliotekanauki.pl/articles/1409049.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    structural control system
    vibration
    simple fractions
    synthesis
    rational functions
    dynamic characteristics
    Opis:
    The paper formulates and formalises a method for selecting parameters of the tuned mass damper (TMD) for primary systems with many degrees of freedom. The method presented uses the properties of positive rational functions, in particular their decomposition, into simple fractions and continued fractions, which is used in the mixed method of synthesis of vibrating mechanical systems. In order to formulate a method of tuning a TMD, the paper discusses the basic properties of positive rational functions. The main assumptions of the mixed synthesis method is presented, based on which the general method of determining TMD parameters in the case of systems with many degrees of freedom was formulated. It has been shown that a tuned mass damper suppresses the desired resonance zone regardless of where the excitation force is applied. The advantages of the formulated method include the fact of reducing several forms of the object’s free vibration by attaching an additional system with the number of degrees of freedom corresponding to the number of resonant frequencies reduced. In addition, the tuned mass damper determined in the case of excitation force applied at a single point can be attached to any element of the inertial primary system without affecting the reduction conditions in this way. It results directly from the methodology formalised in the paper. As part of the paper, numerical calculations were performed regarding the tuning of the TMD to the first form of free vibration of a system with 3 degrees of freedom. The parameters determined were subjected to analysis and verification of the correctness of the calculations carried out. For the considered case of a system with 3 degrees of freedom together with a TMD, time responses of displacement, from each floor, were generated to excitation induced by a harmonic force equal to the first form of vibration of the basic system. In addition, in the case of the parameters obtained, the response of the inertial element system to which the TMD was attached to random white noise excitation was determined.
    Źródło:
    Archives of Control Sciences; 2021, 31, 1; 185-211
    1230-2384
    Pojawia się w:
    Archives of Control Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The structural control of the Mroczna Cave development on the slopes of Mt Kornuty (the Flysch Carpathians, Beskid Niski Mts)
    Autorzy:
    Zatorski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/295108.pdf
    Data publikacji:
    2014
    Wydawca:
    Stowarzyszenie Geomorfologów Polskich
    Tematy:
    mass movements
    flysch Carpathians
    crevice-type cave
    structural control
    anisotropic rock massif
    Opis:
    The Mroczna Cave is one of the longest caves in the Beskid Niski Mts., located on the south-western slopes of Mt Kornuty, along the main scarp of the landslide. According to the geomechanical criterion, it is dilation cave, where extension has played a major role. Morphotectonic analysis indicates that the main gravitational movement was of a toppling nature but there were also rotation around the vertical axis as well as a backward rotation. The relatively large cave depth (15.5 m) and its shape (cross-section of its passages) indicate that it was formed along a new gravitational cutting surface of the rock massif, associated with joint sets.
    Źródło:
    Landform Analysis; 2014, 27; 55-65
    1429-799X
    Pojawia się w:
    Landform Analysis
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Geological control on the Osława River meander at Duszatyn, Western Bieszczady Mountains, Polish Outer Carpathians
    Autorzy:
    Margielewski, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/191585.pdf
    Data publikacji:
    2004
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    neotectonics
    structural control
    Quaternary alluvium
    Osława River
    Western Bieszczady Mountains
    Polish Outer Carpathians
    Opis:
    At Duszatyn village (Western Bieszczady Mts.), the Osława River forms an unique meander loop which is not typical for the mountainous area. Detailed analysis has shown that this landform was created due to the evolution of two left-hand tributaries of the Osława River during the formation of its regressive water-gap. These processes were determined by mass movements which have strongly stimulated the fluvial system. The origin of the Osława River meander was largely controlled by lithological differences in rock resistance, orientation of the joint pattern, as well as the presence of bordering oblique and thrust faults which have had a bearing on the diversified neotectonic uplift of the area.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2004, 74, No 3; 325-338
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Active noise control with a single nonlinear control filter for a vibrating plate with multiple actuators
    Autorzy:
    Mazur, K.
    Pawełczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/176906.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    active noise-vibration control
    active structural acoustic control
    adaptive control
    nonlinear control
    Opis:
    Vibrating plates can be used in Active Noise Control (ANC) applications as active barriers or as secondary sources replacing classical loudspeakers. The system with vibrating plates, especially when nonlinear MFC actuators are used, is nonlinear. The nonlinearity in the system reduces performance of classical feedforward ANC with linear control filters systems, because they cannot cope with harmonics generated by the nonlinearity. The performance of the ANC system can be improved by using nonlinear control filters, such as Artificial Neural Networks or Volterra filters. However, when multiple actuators are mounted on a single plate, which is a common practice to provide effective control of more vibration modes, each actuator should be driven by a dedicated nonlinear control filter. This significantly increases computational complexity of the control algorithm, because adaptation of nonlinear control filters is much more computationally demanding than adaptation of linear FIR filters. This paper presents an ANC system with multiple actuators, which are driven with a single nonlinear filter. To avoid destructive interference of vibrations generated by different actuators the control signal is filtered by appropriate separate linear filters. The control system is experimentally verified and obtained results are reported.
    Źródło:
    Archives of Acoustics; 2013, 38, 4; 537-545
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Weak compactness in the space of operator valued measures $M_ba(Σ,(X,Y))$ and its applications
    Autorzy:
    Ahmed, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/729361.pdf
    Data publikacji:
    2011
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    space of operator valued measures
    weak compactness
    semigroups of bounded linear operators
    optimal structural control
    Opis:
    In this note we present necessary and sufficient conditions characterizing conditionally weakly compact sets in the space of (bounded linear) operator valued measures $M_{ba}(Σ,(X,Y))$. This generalizes a recent result of the author characterizing conditionally weakly compact subsets of the space of nuclear operator valued measures $M_{ba}(Σ,₁(X,Y))$. This result has interesting applications in optimization and control theory as illustrated by several examples.
    Źródło:
    Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2011, 31, 2; 231-247
    1509-9407
    Pojawia się w:
    Discussiones Mathematicae, Differential Inclusions, Control and Optimization
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Internal Model Control for a Light-Weight Active Noise-Reducing Casing
    Autorzy:
    Mazur, K.
    Pawełczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/177886.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    active noise-vibration control
    active structural acoustic control
    active casing
    Internal Model Control
    Opis:
    The active noise-reducing casing developed and promoted by the authors in recent publications have multiple advantages over other active noise control methods. When compared to classical solutions, it allows for obtaining global reduction of noise generated by a device enclosed in the casing. Moreover, the system does not require loudspeakers, and much smaller actuators attached to the casing walls are used instead. In turn, when compared to passive casings, the walls can be made thinner, lighter and with much better thermal transfer than sound-absorbing materials. For active noise control a feedforward structure is usually used. However, it requires an in-advance reference signal, which can be difficult to be acquired for some applications. Fortunately, usually the dominant noise components are due to rotational operations of the enclosed device parts, and thus they are tonal and multitonal. Therefore, it can be adequately predicted and the Internal Model Control structure can be used to benefit from algorithms well developed for feedforward systems. The authors have already tested that approach for a rigid casing, where interaction of the walls was significantly reduced. In this paper the idea is further explored and applied for a light-weight casing, more frequently met in practice, where each vibrating wall of the casing influences all the other walls. The system is verified in laboratory experiments.
    Źródło:
    Archives of Acoustics; 2016, 41, 2; 315-322
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hammerstein Nonlinear Active Noise Control with the Filtered-Error LMS Algorithm
    Autorzy:
    Mazur, K.
    Pawełczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/176841.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    active noise-vibration control
    active structural acoustic control
    adaptive algorithm
    nonlinear system
    Opis:
    Active Noise Control (ANC) of noise transmitted through a vibrating plate causes many problems not observed in classical ANC using loudspeakers. They are mainly due to vibrations of a not ideally clamped plate and use of nonlinear actuators, like MFC patches. In case of noise transmission though a plate, nonlinerities exist in both primary and secondary paths. Existence of nonlinerities in the system may degrade performance of a linear feedforward control system usually used for ANC. The performance degradation is especially visible for simple deterministic noise, such as tonal noise, where very high reduction is expected. Linear feedforward systems in such cases are unable to cope with higher harmonics generated by the nonlinearities. Moreover, nonlinearities, if not properly tackled with, may cause divergence of an adaptive control system. In this paper a feedforward ANC system reducing sound transmitted through a vibrating plate is presented. The ANC system uses nonlinear control filters to suppress negative effects of nonlinearies in the system. Filtered-error LMS algorithm, found more suitable than usually used Filtered-reference LMS algorithm, is employed for updating parameters of the nonlinear filters. The control system is experimentally verified and obtained results are discussed.
    Źródło:
    Archives of Acoustics; 2013, 38, 2; 197-203
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Double Panel Structure for Active Control of Noise Transmission
    Autorzy:
    Morzyński, L.
    Szczepański, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/176968.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    noise
    sound insulating enclosure
    active structural acoustic control
    virtual microphone
    Opis:
    Passive noise reduction means are commonly used to reduce noise in the industry but, unfortunately, their effectiveness is poor in the low frequency range. By applying active structural acoustic control to the enclosure walls significant improvement of the insulating properties in this frequency range can be achieved. In this paper a model of double panel structure with ASAC is presented. The structure consists of two aluminium plates separated by an air gap. Two inertial magnetoelectric actuators and two piezoceramic MFC sensors were used for controlling the structure. A multichannel FxLMS algorithm with virtual error microphone technique is used as a control algorithm. The signal of a virtual error microphone is extrapolated basing on signals from MFC sensors. Performance of this actively controlled structure for tonal signals at selected frequencies is presented in the article. During the study, a double panel structure was mounted on one wall of sound insulating enclosure located in an acoustic chamber. During the measurements local and global reduction of noise test signal was investigated.
    Źródło:
    Archives of Acoustics; 2018, 43, 4; 689-696
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Active Noise-Vibration Control using the Filtered-Reference LMS Algorithm with Compensation of Vibrating Plate Temperature Variation
    Autorzy:
    Mazur, K.
    Pawełczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/177469.pdf
    Data publikacji:
    2011
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    active noise-vibration control
    active structural acoustic control
    adaptive control
    gain scheduling
    temperature influence
    Opis:
    Vibrating plates have been recently used for a number of active noise control applications. They are resistant to difficult environmental conditions including dust, humidity, and even precipitation. However, their properties significantly depend on temperature. The plate temperature changes, caused by ambient temperature changes or plate heating due to internal friction, result in varying response of the plate, and may make it significantly different than response of a fixed model. Such mismatch may deteriorate performance of an active noise control system or even lead to divergence of a model-based adaptation algorithm. In this paper effects of vibrating plate temperature variation on a feedforward adaptive active noise reduction system with the multichannel Filtered-reference LMS algorithm are examined. For that purpose, a thin aluminum plate is excited with multiple Macro-Fiber Composite actuators. The plate temperature is forced by a set of Peltier cells, what allows for both cooling and heating the plate. The noise is generated at one side of the plate, and a major part of it is transmitted through the plate. The goal of the control system is to reduce sound pressure level at a specified area on the other side of the plate. To guarantee successful operation of the control system in face of plate temperature variation, a gain-scheduling scheme is proposed to support the Filteredreference LMS algorithm.
    Źródło:
    Archives of Acoustics; 2011, 36, 1; 65-76
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Feedforward Control of a Light-Weight Device Casing for Active Noise Reduction
    Autorzy:
    Wrona, S.
    Pawelczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/177744.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    active control
    flexible structures
    active noise control
    active vibration control
    active structural acoustic control
    active casing
    Opis:
    It is possible to enhance acoustic isolation of the device from the environment by appropriately controlling vibration of a device casing. Sound insulation efficiency of this technique for a rigid casing was confirmed by the authors in previous publications. In this paper, a light-weight casing is investigated, where vibrational couplings between walls are much greater due to lack of a rigid frame. A laboratory setup is described in details. The influence of the cross-paths on successful global noise reduction is considered. Multiple vibration actuators are installed on each of the casing walls. An adaptive control strategy based on the Least Mean Square (LMS) algorithm is used to update control filter parameters. Obtained results are reported, discussed, and conclusions for future research are drawn.
    Źródło:
    Archives of Acoustics; 2016, 41, 3; 499-505
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Topological dual of $B_∞(I, ₁(X,Y))$ with application to stochastic systems on Hilbert space
    Autorzy:
    Ahmed, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/729390.pdf
    Data publikacji:
    2009
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    representation theory
    topological dual
    finitely additive operator-valued measures
    polish space
    Hilbert space
    stochastic systems
    structural control
    uncertainty abatement
    Opis:
    In this paper, we prove that the topological dual of the Banach space of bounded measurable functions with values in the space of nuclear operators, furnished with the natural topology, is isometrically isomorphic to the space of finitely additive linear operator-valued measures having bounded variation in a Banach space containing the space of bounded linear operators. This is then applied to a stochastic structural control problem. An optimal operator-valued measure, considered as the structural control, is to be chosen so as to minimize fluctuation (volatility). Both existence of optimal policy and necessary conditions of optimality are presented including a conceptual algorithm.
    Źródło:
    Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2009, 29, 1; 67-90
    1509-9407
    Pojawia się w:
    Discussiones Mathematicae, Differential Inclusions, Control and Optimization
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Comparing the efficiency of different structural skeleton for base isolated domes
    Autorzy:
    Casciati, Sara
    Powiązania:
    https://bibliotekanauki.pl/articles/27311406.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    base isolation
    design requirements
    dome
    isolation device
    passive structural control
    wymagania projektowe
    kopuła
    urządzenie izolujące
    izolacja sejsmiczna
    kontrola strukturalna pasywna
    Opis:
    The structural concept of the dome dates back to the Pantheon in Rome. It is used as the cover of many churches and mosques all around the world. Light solutions, with a well-visible dome-shaped truss skeleton, are often preferred in modern architecture. Base isolation techniques can be adopted to mitigate the seismic effects. This paper aims to investigate the efficiency of different designs for the truss skeleton. To solve the problem, one has to assign the constraints, the materials and the geometry of the dome, its supporting structure and the isolation devices (number, locations, and type). The screening of the effects of different scheme assumptions on structural behaviour provides a better insight into the problem.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 3; art. no. e143555
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Interaction between tectonics, plutonism and mineralization of the Duna Pb-Ba ore deposit regarding fluid inclusion study (Central Alborz, Iran)
    Autorzy:
    Sadeghi, Alireza
    Asiabar, Saeid Hakimi
    Nezafati, Nima
    Ganji, Alireza
    Mukherjee, Soumyajit
    Powiązania:
    https://bibliotekanauki.pl/articles/27323967.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    Alborz
    overprinting tectonics
    plutonism
    fluid inclusion
    structural control
    duna type ore deposit
    Pb-Ba ore deposit
    carbonate-hosted
    Elburs
    plutonizm
    inkluzja fluidalna
    sterowanie strukturalne
    złoża rud
    Opis:
    This article discusses the impacts of overprinting of tectonic and plutonic events on the mineralization of the Duna Pb-Ba ore deposit, according to geologic settings and fluid inclusion studies. The Duna carbonate-hosted deposit contains a significant amount of Ag (18.9–264.3 ppm ), Cu (77–41600 ppm), Sb (32.7–11000 ppm), Sr (63.5–15100 ppm), and Fluid inclusions with 7.34–23.65 wt.% NaCl equivalent. The homogenization temperature of about 110–285°C, as well as the paragenesis of the minerals shows a difference compared with other Pb-Zn deposits such as the Irish-type and MVT. The ore mineralization in the Duna mine occurred as stratabound, open space-filling, and along the brecciated fault zones. The concordant (stratabound) type of mineralization, with salinity and homogenization temperature of 18.54 to 23.65 wt.% NaCl equivalent, and 113°C to 165°C respectively, is usually typical of MVT-ore deposits, which in this area evolved during the Early Cimmerian orogeny and was later interrupted by mineralization along younger brecciated fault zones with salinity and homogenization temperature of 7.34 to 23.65 wt.% NaCl equivalent, and 113°C to 285°C respectively. This discordant mineralization, which occurred along the faults, formed by the end of the Late Cretaceous and during the Cenozoic as a result of the intrusion of a plutonic mass, and is comparable to the Irish-type ore deposits.
    Źródło:
    Acta Geologica Polonica; 2023, 73, 2; 201--222
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optimal passive structural control under extreme earthquake excitations using a combined pendulum tuned mass damper
    Autorzy:
    Kamel, Abanoub G.
    Basily, Remon M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2175498.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
    Tematy:
    passive structural control
    earthquake excitations
    offshore platform
    Tuned Mass Damper
    mathematical modelling
    MATLAB©
    pasywna kontrola konstrukcji
    wzbudzenia trzęsień ziemi
    platforma morska
    wielokrotne strojone tłumiki masowe
    modelowanie matematyczne
    Opis:
    Many engineering applications utilize passive Tuned Mass Dampers (TMDs) in several engineering applications because of their simplicity, readiness, and their ability in attenuating structural vibrations exposed to mild or extreme earthquake excitations. The main aim of this work is to find the optimum values of the system parameters after attaching a three degree of freedom Combined Pendulum Tuned Mass Damper (3-DOF CPTMD) to the main structure to investigate if the proposed solution will assist in reducing the amplitudę of the vibration. Three optimization search techniques are utilized, and the best optimum method is determined. Moreover, the structural system was modelled mathematically to get the governing motion equations, and the system was put into state-space format before being simulated using a homemade MATLAB© code. Additionally, it is found that the proposed 3-DOF CPTMD is very effective in dampening the structural vibrations under various earthquake excitations (including extreme conditions)
    Źródło:
    Journal of Applied Mathematics and Computational Mechanics; 2021, 20, 4; 51--64
    2299-9965
    Pojawia się w:
    Journal of Applied Mathematics and Computational Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Active Transient Sound Radiation Control from a Smart Piezocomposite Hollow Cylinder
    Autorzy:
    Hasheminejad, S. M.
    Rabbani, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/177572.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    active structural acoustic control (ASAC) thick cylindrical shells
    exact elasto-acoustic analysis
    time-domain solution
    intelligent system
    sound field attenuation
    Opis:
    The linear 3D piezoelasticity theory along with active damping control (ADC) strategy are applied for non-stationary vibroacoustic response suppression of a doubly fluid-loaded functionally graded piezolaminated (FGPM) composite hollow cylinder of infinite length under general time-varying excitations. The control gain parameters are identified and tuned using Genetic Algorithm (GA) with a multi-objective performance index that constrains the key elasto-acoustic system parameters and control voltage. The uncontrolled and controlled time response histories due to a pair of equal and opposite impulsive external point loads are calculated by means of Durbin’s numerical inverse Laplace transform algorithm. Numerical simulations demonstrate the superior (good) performance of the GA-optimized distributed active damping control system in effective attenuation of sound pressure transients radiated into the internal (external) acoustic space for two basic control configurations. Also, some interesting features of the transient fluid-structure interaction control problem are illustrated via proper 2D time domain images and animations of the 3D sound field. Limiting cases are considered and accuracy of the formulation is established with the aid of a commercial finite element package as well as comparisons with the current literature.
    Źródło:
    Archives of Acoustics; 2015, 40, 3; 359-381
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Strukturalne uwarunkowania rozwoju rzeźby Karpat zewnętrznych : nowe spojrzenie
    Structural control on the Outer Carpathians relief : a new approach
    Autorzy:
    Jankowski, L.
    Margielewski, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075092.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    relief transformation
    structural control
    compressional-extensional stages
    back thrusting
    gravitational tectonics
    faulting
    chaotic complexes
    Polish Outer Carpathians
    rozwój tektoniczno-basenowy Karpat
    rozwój rzeźby
    uskoki
    kompleksy chaotyczne
    strukturalne uwarunkowania
    Polskie Karpaty Zewnętrzne
    Opis:
    The article presents a new concept of structural control on the Outer Carpathians relief. The Carpathians’ relief development originated in the stage of sedimentary basin deposition (e.g., gravitational positioning of fragments of rock massif), as well as in the compressional stage of the orogen formation, and, finally, in the stage of secondary tectonic deformation, such as: strike-slip faulting, radial extension, and great extensional collapse of the Carpathian massifs. The difference in elevation between the Beskidy Mts. and Carpathian Foothills belt is caused by the structural position of these segments of rock massifs within an accretionary prism formed during the compressional stage. The tectonic elements formed during the earliest stage of compression (Magura, Dukla and southern Silesian units forming the High Beskid zone) attain the highest structural and elevation position, whereas the elements included as the last ones to the accretionary prism (Sub-Silesian and Skole units) take a lower topographic position, forming the foothills belt. A concept that gravitational collapse generated back-thrusts and tectonic exhumation of the Carpathian massifs allows us to explain seemingly considerable erosional unroofing of the Carpathian surface, estimated at several kilometres. Alternating position of elevated and lowered mountain ridges (Bieszczady–Beskid Niski–Beskid Wyspowy–Beskid Makowski Mts.) can be explained by their association with a major strike-slip fault. Chaotic complexes frequently occurring in the Carpathians are very important for the relief transformation and development of river network (controlled not only by dislocations, but also by chaotic complexes), as well as for the presence of erosional remnants (isolated hills representing blocks in matrix).
    Źródło:
    Przegląd Geologiczny; 2014, 62, 1; 29--35
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Feed-forward compensation for nonlinearity of vibrating plate as the sound source for active noise control
    Kompensacja nieliniowości płyty drgającej jako źródła dźwięku dla systemów aktywnej redukcji hałasu
    Autorzy:
    Mazur, K.
    Pawełczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/368955.pdf
    Data publikacji:
    2011
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    aktywna redukcja hałasu
    płyta drgająca
    nieliniowe sterowanie
    kompensacja
    emisja dźwięku
    adaptacja
    ekwalizacja
    active noise control
    active structural acoustic control
    vibrating plate
    sound radiation
    adaptation
    feed-forward
    equalization
    nonlinear control
    Opis:
    Active Noise Control (ANC) systems are usually designed in the feed-forward structure with adaptive linear control filters. However, performance of such systems, when a vibrating plate is used as the secondary source, may be poor due to significant non-linearity of the plate response. The linear systems are then unable to cope with higher harmonics generated by the nonlinearity. One solution to this problem is to apply a nonlinear ANC algorithm. However, it adds additional complexity to this layer. It is particularly severe for multichannel systems, where the algorithms are complex by themselves, and making them nonlinear may significantly reduce their scalability. In this paper, another approach is proposed. Multiple actuators are mounted on a single plate, in order to effectively excite more vibration modes and generate a higher acoustic power, than in case of a single actuator. The response of the vibrating plate as the sound source is then linearized with a set of nonlinear finite impulse response filters, operating individually for each actuator. The Filtered-x LMS algorithm is adopted to update parameters of the nonlinear filters. The control system is experimentally verified and obtained results are reported.
    Systemy aktywnej redukcji hałasu zwykle projektowane są w strukturze kompensacyjnej z adaptacyjnymi liniowymi filtrami sterującymi. Wówczas, w przypadku zastosowania płyty drgającej jako źródła dźwięku, skuteczność działania może być zmniejszona z powodu występujących nieliniowości w torze wtórnym. Liniowy układ kompensacji nie jest w stanie poradzić sobie z wyższymi harmonicznymi generowanymi przez nieliniowości. Jednym z rozwiązań jest zastosowanie nieliniowego algorytmu aktywnej redukcji hałasu. Zwiększa to jednak złożoność układu w tej warstwie sterowania. W przypadku wielokanałowych systemów aktywnej redukcji hałasu, które same w sobie są złożone, wprowadzenie nieliniowości w algorytmie znacząco zmniejsza skalowalność całego systemu. W niniejszym artykule zaproponowane jest inne podejście. Aby zapewnić efektywne pobudzenie większej liczby mod i uzyskanie większej mocy akustycznej jak w przypadku pojedynczego elementu wzbudzającego, zastosowano wiele elementów wykonawczych wzbudzających drgania. Odpowiedź płyty drgającej pełniącej rolę złożonego źródła dźwięku jest linearyzowana przez zbiór nieliniowych filtrów o skończonej odpowiedzi impulsowej działających niezależnie na poszczególne elementy wykonawcze. Do aktualizacji parametrów filtrów nieliniowych zastosowany jest algorytm Filtered-x LMS. Zaproponowany system sterowania został poddany weryfikacji eksperymentalnej, a uzyskane wyniki zostały zaprezentowane i skomentowane.
    Źródło:
    Mechanics and Control; 2011, 30, 3; 146-150
    2083-6759
    2300-7079
    Pojawia się w:
    Mechanics and Control
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dwupłytowa struktura aktywna do ograniczania transmisji hałasu przez obudowy i przegrody dźwiękoizolacyjne
    Double-layered active structure for reducing noise transmission through sound insulating barriers
    Autorzy:
    Morzyński, L.
    Krukowicz, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/181117.pdf
    Data publikacji:
    2017
    Wydawca:
    Centralny Instytut Ochrony Pracy
    Tematy:
    hałas
    obudowa dźwiękoizolacyjna
    akustyczno-strukturalna aktywna redukcja hałasu
    mikrofon wirtualny
    noise
    sound insulation
    sound insulation enclosure
    active structural acoustic control
    virtual microphone
    Opis:
    Obudowy dźwiękoizolacyjne są jednym i podstawowych środków technicznych, stosowanych powszechnie do ograniczania hałasu. Izolacyjność przegród pasywnych maleje jednak ze spadkiem częstotliwości dźwięku. Izolacyjność w zakresie niskich częstotliwości może być zwiększona poprzez zastosowanie aktywnych metod redukcji hałasu. W artykule przedstawiono budowę i zasadę działania dwupłytowej struktury aktywnej do ograniczania transmisji hałasu przez przegrody. Do sterowania przegrodą korzystano algorytm z ekstrapolacją sygnału błędu w oparciu o sygnały z przetworników drganiowych Przedstawiono wyniki badań struktury na stanowisku laboratoryjnym.
    Sound insulating enclosures are a basic technical measure commonly used to reduce noise. Insulation of passive sound insulating barriers, however, decreases with a decrease in frequency. Insulation in the low frequency range can be increased by using active noise control methods. This article presents the structure and principle of operation of a double-layered active structure to limit the transmission of noise through barriers. An algorithm, which extrapolates the error microphone signal based on signals from the vibration transducers, is used for structure control. This article presents structure performance in laboratory conditions.
    Źródło:
    Bezpieczeństwo Pracy : nauka i praktyka; 2017, 10; 24-28
    0137-7043
    Pojawia się w:
    Bezpieczeństwo Pracy : nauka i praktyka
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Active Transient Acousto-Structural Response Control of a Smart Cavity-Coupled Circular Plate System
    Autorzy:
    Hasheminejad, S. M.
    Shakeri, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/176771.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    sound radiation
    structural-borne noise control
    coupled multi-field problem
    piezoelectric disc actuator
    cylindrical enclosure
    GA-tuned controller
    Opis:
    The transient vibroacoustic response suppression of a piezo-coupled sandwich circular plate backed by a rigid-walled cylindrical acoustic enclosure is investigated. Problem formulation is based on the linear acoustic wave theory, Kirchhoff thin plate model, fluid/structure compatibility relations, Rayleigh integra formula, and active damping control (ADC) strategy. Matlab’s Genetic Algorithm (GA) is utilized to identify and optimize the feedback controller gain parameter based on a multi-objective performance index function. Durbin’s numerical Laplace inversion scheme is then used to calculate the key acousto-structural response parameters due to a transverse impulsive shock force for selected cavity depths. Numerical simulations demonstrate satisfactory performance of adopted control methodology in effective suppression of panel displacement response and radiated external sound pressure for enclosures of shallow and moderate depths. Limiting cases are considered and accuracy of the proposed model is rigorously verified.
    Źródło:
    Archives of Acoustics; 2017, 42, 2; 273-286
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Leaky partial updates to control a real device casing
    Autorzy:
    Bismor, Dariusz
    Powiązania:
    https://bibliotekanauki.pl/articles/24201999.pdf
    Data publikacji:
    2022
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    structural active noise control
    partial updates
    leaky LMS
    signal processing
    strukturalna aktywna redukcja hałasu
    aktualizacje częściowe
    LMS z wyciekiem
    przetwarzanie sygnałów
    Opis:
    Structural active noise control (ANC) is one of few solutions applicable when global noise reduction is required: control of a whole device casing allows to lower the acoustic energy emitted by this device. Unfortunately, structural ANC usually requires a large number of sensors and actuators, making the control system multichannel with large dimensionality. This in turn presents a huge computational power demands. There are several ways to lower this demand, the partial updates being one of them. The goal of this paper is to show applicability of the leaky partial update LMS algorithms in structural ANC of a washing machine casing. The transfer functions of the numerous device paths were identified using a real washing machine in the ANC laboratory. The identified transfer functions allowed to create a simulation system, where different algorithms could be easily tested. The results of the simulations confirm effectiveness of the proposed solution.
    Źródło:
    Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022304
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Robust control design of a smart building structure
    Projektowanie sterowania odpornego w "inteligentnych" konstrukcjach budowlanych
    Autorzy:
    Marinova, D. G.
    Stavroulakis, G. E.
    Powiązania:
    https://bibliotekanauki.pl/articles/280816.pdf
    Data publikacji:
    2007
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    robust control
    structural controI
    applied optimization
    uncertainty system
    Opis:
    This paper presents an application of a design method of robust H... optimal controI to a structural controI system. A dynamic model for a building structure under earthquake and wind excitations is considered. Structured uncertainties are introduced to reflect errors between the model and the reality. To obtain the best possible performance in the face of uncertainties, rob ust H... optimal controI for the active controI structure is used. Relevant numerical techniques, which have been implemented wit h the help of MATLAB routines, are applied to solve the formulated structural contral problem. By proper selection of the weight factor, the seismic response of the building structure can be reduced considerably. Numerical results show high robust performance of the proposed method.
    Praca przedstawia aplikację metody projektowania optymalnego sterowania odpornego H... dla celów konstrukcyjnych. Rozważono dynamiczny model konstrukcji budowlanej poddanej obciążeniu trzęsieniem ziemi oraz wiatrem. Wprowadzono niepewność strukturalną do modelu, aby odzwierciedlić błędy wynikające z różnic między modelem i budynkiem rzeczywistym. Do uzyskania najlepszego działania układu sterowania w obecności założonego poziomu niepewności parametrów użyto w analizowanej aktywnej konstrukcji tzw. sterowania odpornego H... . W rozwiązywaniu problemu sterowania zastosowano symulacje numeryczne wspomagane gotowymi procedurami zaczerpniętymi ze środowiska MATLAB. Poprzez odpowiedni dobór współczynnika wagi uzyskano znaczący efekt redukcji wrażliwości sejsmicznej budynku. Wyniki badań pokazały wysoką odporność zaproponowanego układu sterowania.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2007, 45, 1; 73-90
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Model based predictive control of guyed mast vibration
    Predykcyjne sterowanie drganiami masztów z odciągami
    Autorzy:
    Błachowski, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/281574.pdf
    Data publikacji:
    2007
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    structural vibrations
    vibration control
    guyed masts
    wind fluctuations
    Opis:
    The purpose of this work is to present an algorithm for optimal vibration control of guyed masts and an example of its application to a numerical simulation. The objective of the proposed contral system is to minimize amplitudes of transverse vibrations of the top of a mast induced by wind pressure acting on the structure. Control forces are assumed to be physically realized through changes of tension in guy cables, supporting the mast. The only required measurements are velocities of guy cables at the anchor-points. On the basis of those, a complete state of deformation of the structure is obtained by using the Kalman filter. The Davenport spectral density function is adopted as a model of the stochastic action of the wind.
    Celem pracy jest algorytm i jego przykładowe zastosowanie do symulacji numerycznej optymalnego sterowania drganiami masztów z odciągami. Zadaniem układu sterowania jest minimalizacja amplitud poprzecznych drgań wierzchołka masztu wywołanych oddziaływaniem wiatru. Realizacja sił sterowania odbywa się poprzez zmianę naciągu w odciągach masztu. Estymacja pełnego stanu deformacji konstrukcji na podstawie pomiaru jedynie prędkości w punktach zakotwienia odciągów uzyskana jest poprzez wykorzystanie filtru Kalmana. Do zamodelowania losowego oddziaływania wiatru użyto funkcję gęstości widmowej Davenporta.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2007, 45, 2; 405-423
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Teoreticheskie obosnovanie ispolzovanija magnitnogo strukturnogo analiza dlja otsenki mekhanicheskikh svojjstv detalejj
    The theoretical grounding of using of the magnetic structural analysis to evaluate the properties of details
    Autorzy:
    Vlasovec, V.
    Naymenko, A.
    Zaiec, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/76503.pdf
    Data publikacji:
    2015
    Wydawca:
    Komisja Motoryzacji i Energetyki Rolnictwa
    Tematy:
    structural analysis
    agricultural equipment
    magnetic control
    mechanical property
    Źródło:
    Motrol. Motoryzacja i Energetyka Rolnictwa; 2015, 17, 7
    1730-8658
    Pojawia się w:
    Motrol. Motoryzacja i Energetyka Rolnictwa
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Decentralized structural control approach for Petri nets
    Autorzy:
    Aybar, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/969777.pdf
    Data publikacji:
    2007
    Wydawca:
    Polska Akademia Nauk. Instytut Badań Systemowych PAN
    Tematy:
    discrete event systems
    Petri nets
    decentralized control
    structural controller
    Opis:
    The structural controller, described by adding the control places to the Petri nets, is introduced in this work to lead the Petri net to the desired marking vectors. An algorithm (Algorithm I) is developed to determine the control places for the given Petri net. The connections and the initial marking of each control place are determined in this algorithm. Moreover, a decentralized structural control approach, based on overlapping decompositions, is introduced in this work. In this decentralized approach, all disjoint Petri subnets, which are obtained by using overlapping decompositions, are determined. The control places for each Petri subnet are determined by using the given algorithm. Then, the control places for the orginal Petri net are obtained by the control places of each PSN by another algorithm (Algorithm II) and these places are added to the orginal Petri net. Therefore, a decentralized structural controller which guarantees to lead the Petri net to the desired marking vectors is obtained.
    Źródło:
    Control and Cybernetics; 2007, 36, 1; 143-159
    0324-8569
    Pojawia się w:
    Control and Cybernetics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Structural contradictions in control system by enterprises as function of associate administrative decisions
    Autorzy:
    Kalyuzhna, N.
    Golovkova, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/411333.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Oddział w Lublinie PAN
    Tematy:
    control system
    administrative decision
    algorithm
    structural contradiction
    morphological matrix
    Opis:
    The key role of organizationally-functional structure improvement of management is reasonable in the increase of efficiency of preparation processes, acceptance and realization of administrative decisions on an enterprise. The algorithm of structural exposure contradictions is offered in control system by an enterprise. The morphological matrix of description of structural contradiction as functions of associate administrative decisions is formed. Sources 22.
    Źródło:
    ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2013, 2, 3; 33-40
    2084-5715
    Pojawia się w:
    ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On convergence of the Monotone Structural Evolution
    Autorzy:
    Korytowski, A.
    Szymkat, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/206572.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Instytut Badań Systemowych PAN
    Tematy:
    optimal control
    direct computational methods
    gradient optimization
    monotone structural evolution
    Opis:
    The paper studies convergenceof the Monotone Structural Evolution (MSE), a computational method of optimal control. The principles of MSE are described and an expository example presents the method in action. It is then proved that under appropriate assumptions the method is convergent to the decision space stationarity conditions. Observations on finite convergence and on connections with Pontryagin’s maximum principle are also provided.
    Źródło:
    Control and Cybernetics; 2016, 45, 4; 483-512
    0324-8569
    Pojawia się w:
    Control and Cybernetics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Litologiczno-strukturalne uwarunkowania rzeźby Sudetów
    Lithological and structural control on the relief of the Sudetes.
    Autorzy:
    Migoń, P.
    Placek, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075095.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    rock control
    structural geomorphology
    rock strength
    Sudetes
    geomorfologia strukturalna
    skały
    spękania
    Sudety
    Opis:
    The geomorphological landscape of the Sudetes consists of elements of diverse origin. While the gross features of relief are best attributed to up- and downfaulting in the late Cenozoic, landform diversity at a smaller scale results mainly from selective long-term denudation controlled by rock properties. The occurrence of rock- and structure-controlled landforms has long been noted in the Sudetes, but their identification remained at a rather descriptive level. Recent work involving an analysis of digital elevation models, combined with field-based determination of rock strength using Schmidt hammer helped to refine some previous concepts and to identify further relationships between rocks and relief at a medium scale. Many residual convex landforms (hills, ridges) are associated with rocks of markedly higher strength than in the surroundings. Differences in elevations which may be attributed to rock factor, attain 400–500 m, which is a figure comparable with minor fault-bounded horsts. Extensive tracts of low relief are partly rock-controlled too, as they are best developed where adjacent rock complexes show similar strength, whether high or low. By contrast, the presence of escarpments cutting across rock masses of comparable strength on both sides appears to point to faulting as the topography-controlling factor.
    Źródło:
    Przegląd Geologiczny; 2014, 62, 1; 36--43
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Control of Bending-Bending Coupled Vibrations of a rRotating Thin-Walled Composite Beam
    Autorzy:
    Latalski, J.
    Bocheński, M.
    Warmiński, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/176850.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    thin-walled beam
    adaptive materials
    feedback control
    composite beam
    coupled vibrations
    structural tailoring
    Opis:
    The paper presents a study of a possible application of structure embedded piezoelectric actuators to enhance the performance of a rotating composite beam exhibiting the coupled flexural-flexural vibrations. The discussed transversal and lateral bending modal coupling results from the directional properties of the beam’s laminate and ply stacking distribution. The mathematical model of the beam is based on an assumption of cross-sectional non-deformability and it incorporates a number of non-classical effects. The final 1-D governing equations of an active composite beam include both orthotropic properties of the laminate and transversely isotropic properties of piezoelectric layers. The system’s control capabilities resulting from embedded Macro Fiber Composite piezoelectric actuators are represented by the boundary bending moment. To enhance the dynamic properties of the composite specimen under consideration a combination of linear proportional control strategies has been used. Comparison studies have been performed, including the impact on modal coupling magnitude and cross-over frequency shift.
    Źródło:
    Archives of Acoustics; 2014, 39, 4; 605-613
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Structural and Functional Features of Training Future Ecologists
    Autorzy:
    SHOFOLOV, Denys
    RIDEI, Nataliia
    PALAMARCHUK, Svitlana
    KLYMENKO, Lyudmila
    Powiązania:
    https://bibliotekanauki.pl/articles/458029.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet Rzeszowski
    Tematy:
    training management functions
    organizational platform and procedures
    structural and functional components
    training control system
    Opis:
    The article presents the structural and functional features of the training ecologists for sustainable natural resource use, including components: the target (goal, objectives, principles), organizational and substantive (the stages of preparation, organizational and management platform – meaningful, backbone, technological), diagnostic-score (scoring platform; criteria and levels of preparedness).
    Źródło:
    Edukacja-Technika-Informatyka; 2014, 5, 1; 390-394
    2080-9069
    Pojawia się w:
    Edukacja-Technika-Informatyka
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Uwarunkowania skłonności do palenia papierosów. Wyniki modelowania równań strukturalnych
    Autorzy:
    Czaderny, Krzysztof
    Powiązania:
    https://bibliotekanauki.pl/articles/1827684.pdf
    Data publikacji:
    2017-06-02
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    lung cancer
    cancer prevention
    cancer control
    smoking
    masculinity
    childhood
    SEM
    structural equation modeling
    epidemiology
    health gap
    Opis:
    According to the age-period-cohort projection of lung cancer incidence (ICD-10 codes C33-C34), smoking prevention will be crucial for both men and women longevity. Lung cancer remains the main cancer cause of death among males in Poland. In 2014 the number of deaths in Poland caused by lung cancer among men was more than twice as high as for women. The study is focused on identification of attitudes influencing the propensity to smoke, which is performed by structural equation modelling (SEM) based on weighted least squares means and variance adjusted (WLSMV) estimation. Good fit of the presented models is demonstrated by RMSEA, NNFI and CFI values. Reliability of scales is assessed by ordinal alpha and ordinal theta coefficients. Commitment to learning in childhood exhibits the highest standardized effect on propensity to smoke, which is an argument for youth smoking prevention. Structural equation model was estimated for men and women separately because of gender differences in smoking determinants. A strong character, individualism and self-reliance are the factors, which increase smoking propensity among males. These can be treated as features of masculinity and are not statistically important determinants of being a smoker for females. Depressive disorders, being a victim of violence as adults are statistically significant determinants of smoking among women.
    Źródło:
    Studia Demograficzne; 2017, 171, 1; 49-69
    0039-3134
    Pojawia się w:
    Studia Demograficzne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wpływ środków chemicznych stosowanych w rolnictwie na zmiany właściwości mechanicznych i strukturalnych PEHD i PELD
    Influence of the pest control products on the mechanical and structural properties of the PEHD and PELD
    Autorzy:
    Kapcińska-Popowska, D.
    Gościański, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/334106.pdf
    Data publikacji:
    2011
    Wydawca:
    Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Maszyn Rolniczych
    Tematy:
    rolnictwo
    środki chemiczne
    właściwości mechaniczne
    właściwości strukturalne
    PEHD
    PE-LD
    pest control
    mechanical properties
    structural properties
    PELD
    Opis:
    W artykule przedstawiono zmiany właściwości mechanicznych i strukturalnych PEHD i PELD, zachodzące pod wpływem nasycania środkami chemicznymi stosowanymi w rolnictwie.
    The paper presents changes in mechanical and structural properties of the PEHD and PELD occurring as result of the pest control products application in the agriculture.
    Źródło:
    Journal of Research and Applications in Agricultural Engineering; 2011, 56, 1; 71-75
    1642-686X
    2719-423X
    Pojawia się w:
    Journal of Research and Applications in Agricultural Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optimization problems for structural acoustic models with thermoelasticity and smart materials
    Autorzy:
    Lasiecka, Irena
    Powiązania:
    https://bibliotekanauki.pl/articles/729240.pdf
    Data publikacji:
    2000
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    structural acoustic model with thermal effects
    optimal control problem
    smart controls
    nonstandard Riccati equations
    analyticity of semigroups
    Opis:
    Optimization problem for a structural acoustic model with controls governed by unbounded operators on the state space is considered. This type of controls arises naturally in the context of "smart material technology". The main result of the paper provides an optimal synthesis and solvability of associated nonstandard Riccati equations. It is shown that in spite of the unboundedness of control operators, the resulting gain operators (feedbacks) are bounded on the state space. This allows to provide full solvability of the associated Riccati equations. The proof of the main result is based on exploiting propagation of analyticity from the structural component of the model into an acoustic medium.
    Źródło:
    Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2000, 20, 1; 113-140
    1509-9407
    Pojawia się w:
    Discussiones Mathematicae, Differential Inclusions, Control and Optimization
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dynamic programming approach to structural optimization problem - numerical algorithm
    Autorzy:
    Fulmański, P.
    Nowakowski, A.
    Pustelnik, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/255706.pdf
    Data publikacji:
    2014
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    elliptic equations
    optimal shape control
    structural optimization
    stationary Navier-Stokes equations
    dynamic programming
    sufficient optimality condition
    numerical approximation
    Opis:
    In this paper a new shape optimization algorithm is presented. As a model application we consider state problems related to fluid mechanics, namely the Navier-Stokes equations for viscous incompressible fluids. The general approach to the problem is described. Next, transformations to classical optimal control problems are presented. Then, the dynamic programming approach is used and sufficient conditions for the shape optimization problem are given. A new numerical method to find the approximate value function is developed.
    Źródło:
    Opuscula Mathematica; 2014, 34, 4; 699-724
    1232-9274
    2300-6919
    Pojawia się w:
    Opuscula Mathematica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wellposedness of optimal control problems for systems with unbounded controls and partially analytic generators
    Autorzy:
    Lasiecka, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/206185.pdf
    Data publikacji:
    2002
    Wydawca:
    Polska Akademia Nauk. Instytut Badań Systemowych PAN
    Tematy:
    równanie różniczkowe i algebraiczne Riccatiego
    differential and algebraic Riccati equations
    singular estimate
    structural acoustic interactions
    thermoelastic plates
    unbounded control operators
    Opis:
    Wellposedness of differential and algebraic Riccati equations for control systems with unbounded control operators is considered. It is shown that the full-classical Riccati theory is recovered for a class of dynamics, whose generators are partially analytic. Partial analyticity is quantitatively expressed by the validity of the so-called "singular estimates", which is imposed on the composition operator E[sup At]B (A is the generator, B is unbounded control operator. This class comprises the PDE coupled systems with hyperbolic and parabolic components. Two illustrative examples are given in the paper: boumdary/point control of thermal plates with hyperbolic character and point control of structural acoustic interactions. The latter are described by wave equation coupled at an interface to a plate equation.
    Źródło:
    Control and Cybernetics; 2002, 31, 3; 751-777
    0324-8569
    Pojawia się w:
    Control and Cybernetics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Korzyści zastosowania technologii CNC w obróbce materiałów konstrukcyjnych w budownictwie
    The benefits of CNC technology for processing construction materials in the industry
    Autorzy:
    Wieczorek, D.
    Plebankiewicz, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/161840.pdf
    Data publikacji:
    2017
    Wydawca:
    Polski Związek Inżynierów i Techników Budownictwa
    Tematy:
    sektor budowlany
    materiał konstrukcyjny
    obróbka
    sterowanie numeryczne
    CNC
    wprowadzanie danych
    CAD
    construction sector
    structural material
    processing
    computerized numerical control
    data input
    Opis:
    Celem artykułu jest charakterystyka technologii obróbki materiałów budowlanych CNC i porównanie jej z technologią obróbki konwencjonalnej. W artykule omówiono ogólny zarys technologii CNC ze szczególnym wyróżnieniem jej podstawowych zalet i wad oraz przedstawiono wyniki krótkiej analizy porównawczej dotyczącej norm czasu pracy na wykonanie montażu drewnianych elementów konstrukcji dachów budynków lub konstrukcji zwykłych z drewna klejonego warstwowo (GL ), obrabianego w technologii CNC oraz litego drewna tartacznego, przy założeniu ręcznej obróbki drewna sposobem tradycyjnym (konwencjonalnym).
    The aim of this article is a description of CNC construction materials processing technology and compare it with conventional processing technology. This article discusses an overview of the CNC technology with a special distinction of its main advantages and disadvantages, and presents the results of a brief comparative analysis of working time norms for the assembly of structural elements of roofs of glued laminated timber (GL ) of buildings or normal construction, which were processed in the CNC technology and full edged sawn timber, assuming manual wood processing in conventional method.
    Źródło:
    Przegląd Budowlany; 2017, 88, 12; 37-41
    0033-2038
    Pojawia się w:
    Przegląd Budowlany
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-38 z 38

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