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Tytuł:
Linear Abelian Modal Logic
Autorzy:
Mohammadi, Hamzeh
Powiązania:
https://bibliotekanauki.pl/articles/43184005.pdf
Data publikacji:
2024
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
many-valued logic
modal logic
abelian logic
hypersequent calculus
cut-elimination
Opis:
A many-valued modal logic, called linear abelian modal logic \(\rm {\mathbf{LK(A)}}\) is introduced as an extension of the abelian modal logic \(\rm \mathbf{K(A)}\). Abelian modal logic \(\rm \mathbf{K(A)}\) is the minimal modal extension of the logic of lattice-ordered abelian groups. The logic \(\rm \mathbf{LK(A)}\) is axiomatized by extending \(\rm \mathbf{K(A)}\) with the modal axiom schemas \(\Box(\varphi\vee\psi)\rightarrow(\Box\varphi\vee\Box\psi)\) and \((\Box\varphi\wedge\Box\psi)\rightarrow\Box(\varphi\wedge\psi)\). Completeness theorem with respect to algebraic semantics and a hypersequent calculus admitting cut-elimination are established. Finally, the correspondence between hypersequent calculi and axiomatization is investigated.
Źródło:
Bulletin of the Section of Logic; 2024, 53, 1; 1-28
0138-0680
2449-836X
Pojawia się w:
Bulletin of the Section of Logic
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Paracomplete Versions of Jaśkowskis Discussive Logic
Autorzy:
Mruczek-Nasieniewska, Krystyna
Petrukhin, Yaroslav
Shangin, Vasily
Powiązania:
https://bibliotekanauki.pl/articles/43183714.pdf
Data publikacji:
2024
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
discussive logic
discursive logic
modal logic
paracomplete logic
paraconsistent logic
Opis:
Jaśkowski's discussive (discursive) logic \( \mathbf{D_2} \) is historically one of the first paraconsistent logics, i.e., logics which 'tolerate' contradictions. Following Jaśkowski's idea to define his discussive logic by means of the modal logic \( \mathbf{ S5 } \) via special translation functions between discussive and modal languages, and supporting at the same time the tradition of paracomplete logics being the counterpart of paraconsistent ones, we present a paracomplete discussive logic \( \mathbf{ D_2^p } \).
Źródło:
Bulletin of the Section of Logic; 2024, 53, 1; 29-61
0138-0680
2449-836X
Pojawia się w:
Bulletin of the Section of Logic
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary findings and research perspectives on the German modal sollen in L2 written assessments
Autorzy:
Wulff, Nadja
McGury, Sandra
Powiązania:
https://bibliotekanauki.pl/articles/40055994.pdf
Data publikacji:
2024
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
L2 written assessment
writing tasks
L2 modal verbs
CEFR
ocenianie tekstów pisanych w języku obcym
zadania pisemne
czasowniki modalne w języku obcym
ESOKJ
Opis:
Modal verbs represent a special verb category and constitute an essential component of L2 German semantics. While Abrams and Rott (2017) suggest that German learner texts depict a 90% accuracy in the correct use of modal verbs in integrative writing tasks, the correct semantic use of the modal sollen (‘supposed to’; ‘should’) seems to pose a particular challenge (Jentges 2016), especially in an assessment context. In this corpus analysis, 1,032 L2 German assessment texts across all CEFR levels were analyzed with respect to the L2 semantic use of sollen against the backdrop of the assessment prompts. 68% of instances of all uses of sollen in A1 texts and 53% of all uses of sollen in A2 texts showed an inappropriate semantic use of sollen. The discrepancy between these results and Abrams and Rott (2017) can be attributed to the prompts used in the assessments analyzed in this paper: They do not take into consideration the semantic mismatch between the use of the modal in the prompt and its inappropriate use in the texts produced.
Czasowniki modalne są specjalną kategorią czasowników i stanowią istotny element języka niemieckiego jako drugiego (L2). Podczas gdy badanie Abrams i Rott (2017) sugeruje, że teksty pisane przez osoby uczące się języka niemieckiego wykazują 90% dokładność w prawidłowym użyciu czasowników modalnych w zintegrowanych zadaniach pisemnych, prawidłowe semantyczne użycie czasownika modalnego sollen („powinien”) wydaje się stanowić szczególne wyzwanie (Jentges 2016), zwłaszcza w kontekście oceniania. W ramach niniejszego badania korpusowego przeanalizowane zostały 1032 niemieckie teksty egzaminacyjne L2 na wszystkich poziomach CEFR pod kątem poprawności znaczeniowej użycia czasownika modalnego sollen z uwzględnieniem kontekstu pytań egzaminacyjnych. W 68% wszystkich przypadków użycia sollen w tekstach A1 i 53% wszystkich przypadków użycia sollen w tekstach A2 czasownik ten był niewłaściwie zastosowany. Za przyczynę rozbieżności między uzyskanymi wynikami a wynikami Abrams i Rott (2017) można uznać polecenia stosowane w analizowanych zadaniach – nie uwzględniają one rozbieżności semantycznej między użyciem czasownika w instrukcji a jego niewłaściwym użyciem w tworzonych tekstach.
Źródło:
Glottodidactica. An International Journal of Applied Linguistics; 2024, 51, 1; 89-102
0072-4769
Pojawia się w:
Glottodidactica. An International Journal of Applied Linguistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Airborne and Structure-Borne Noise Control in the MB Truck Cabin Interior by the Noise Reduction in the Transmission Path
Autorzy:
Mohammadi, Nader
Powiązania:
https://bibliotekanauki.pl/articles/31339935.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
truck noise sources
airborne noise
structure-borne noise
acoustic materials
viscoelastic layer damping
modal analysis
Opis:
In the current study, investigations are made to control the MB truck cabin interior noise by reducing noise in the transmission path. The main sources of cabin noise include the engine, exhaust system, air inlet system, driveline system, and tyres (especially at higher speeds). Furthermore, vibrations of the body and interior parts of the truck may significantly impact the overall in-cabin sound level. Noise is transmitted into the cabin via air (airborne noise) and cabin structure (structure-borne noise). In the noise treatment phase, noise transmission paths are considered. A viscoelastic layer damping material is used to reduce the vibration amplitude of the cabin back wall. The overall loss factor and vibration amplitude reduction ratio for the structure treated is calculated. Computational results are then compared with the values obtained by the experimental modal analysis results. Choosing the suitable material and thickness can significantly reduce the vibration amplitude. A sound barrier, silicon adhesive, and foam are also utilised for noise control in the transmission path. The effectiveness of the mentioned acoustic materials on cabin noise reduction is evaluated experimentally. The experimental SPL values are reported in the frequency range of 20 Hz–20 kHz based on a 1/3 octave filter. The experimental results show that using acoustics materials reduces the overall in-cabin sound level for a wide range of frequencies.
Źródło:
Archives of Acoustics; 2023, 48, 1; 93-101
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ambiguity in Critical Contexts: The Lexical Split of the German Modal dürfte
Ambiguität in kritischen Kontexten: Der lexical split des deutschen Modalverbs dürfte
Autorzy:
Politt, Katja
Powiązania:
https://bibliotekanauki.pl/articles/36847733.pdf
Data publikacji:
2023-01-24
Wydawca:
Oficyna Wydawnicza ATUT – Wrocławskie Wydawnictwo Oświatowe
Tematy:
Grammatikalisierung
critical contexts
epistemische Modalverben
Deutsch
epistemic modal verbs
German
grammaticalisation
Opis:
The present-day German modal verb dürfen (‘to be allowed to do sth’) is currently undergoing a lexical split in its grammaticalisation. In the subjunctive II, dürfte, it is developing into an epistemic marker of phoric non-factuality used to express a speaker-based judgment of the probability of a given proposition (Politt 2022). Epistemic dürfte thus grammaticalises into the grammatical category mood, whereas its non-epistemic form remains part of a lexical class of modals. While dürfte is known to have progressed quite far on its grammaticalisation path, somewhere between stage 3 and 4, it still shows remnants of grammaticalisation stage 2 (Lehmann 2002, Diewald 2009). The present paper analyses 92 ambiguous sentences of dürfte taken from the DWDS core corpus of the 20th century (Geyken 2007). These sentences are assumed to exhibit critical contexts, which are remnants of grammaticalisation stage 2 (cf. Diewald 2009). They can be interpreted both as epistemic or as non-epistemic. Since the epistemic reading of dürfte is assumed to have developed into the default interpretation for the subjunctive II (Mortelmans 2019, Politt 2022), the ambiguous sentences are analysed in regard to their similarity to typical contexts for epistemic dürfte for three classes of features: (i) features of the subject, (ii) of the verbal complement, and (iii) the sentence context. On the one hand, variation can be found in all three feature classes, indicating that the grammaticalization has not yet progressed fully out of stage 2. On the other hand, a tendency for favouring an epistemic interpretation of the ambiguous sentence could be shown, too, illustrating the developing functional independence of epistemic dürfte.
In seinem Grammatikalisierungsprozess durchläuft das Modalverb dürfen einen sogenannten lexical split: Seine Konjunktiv II-Form dürfte spaltet sich von der ursprünglichen, nicht-epistemischen Bedeutung des Erteilens einer Erlaubnis ab. Sie entwickelt sich zu einem epistemischen Marker phorischer Nichtfaktizität, der sprecher: innenbasierte Einschätzungen der Wahrscheinlichkeit einer Proposition ausdrückt (Politt 2022). Die epistemische Lesart von dürfte wird dabei Teil der grammatischen Kategorie Modus, während die nicht-epistemische Lesart weiterhin Teil der lexikalischen Klasse der Modalverben bleibt. Dürfte ist in seiner Grammatikalisierung bereits weit fortgeschritten und befindet sich zwischen Stufe 3 und 4 seines Grammatikalisierungsprozesses. Jedoch finden sich auch Belege für Reste der Grammatikalisierungsstufe 2 (Lehmann 2002, Diewald 2009). Der vorliegende Beitrag analysiert 92 ambige Belege für dürfte, entnommen aus dem DWDS-Kernkorpus des 20. Jahrhunderts (Geyken 2007), die Beispiele für kritische Kontexte, also rammatikalisierungsstufe 2, darstellen. Sie können sowohl epistemisch als auch nicht-epistemisch interpretiert werden. Die epistemische Lesart von dürfte entwickelt sich zur Default-Interpretation dieser Form (Mortelmans 2019, Politt 2022), weshalb die ambigen Sätze hinsichtlich ihrer Ähnlichkeit zu typischen epistemisch zu interpretierenden Sätzen analysiert werden. Dazu werden die Belege hinsichtlich ihrer Merkmale in drei Klassen betrachtet: (i) Eigenschaften des Subjekts, (ii) des Verbalkomplements und (iii) des Satzkontextes. Hier zeigt sich Variation in allen drei Klassen, was darauf hindeutet, dass dürfte die Grammatikalisierungsstufe 2 noch nicht vollständig verlassen hat. Jedoch kann eine Tendenz zur epistemischen Interpretation festgestellt werden, was die sich entwickelnde funktionale Eigenständigkeit von dürfte im Gegensatz zum nichtepistemischen dürfen illustriert.
Źródło:
Linguistische Treffen in Wrocław; 2023, 24; 117-131
2084-3062
2657-5647
Pojawia się w:
Linguistische Treffen in Wrocław
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An integrated study for solving high vibration problem of a deep well turbine pump
Autorzy:
El-Gazzar, Dalia M.
Powiązania:
https://bibliotekanauki.pl/articles/2203638.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
vibration analysis
finite element analysis
modal analysis
resonance
vertical turbine pump
analiza drgań
analiza elementów skończonych
analiza modalna
rezonans
Opis:
Mechanical vibrations are a common problem encountered in many machines, especially for vertical turbine pumps. These pumps are generally difficult to stiffen or damp, but the effective diagnosis must begin with an understanding of the underlying vibratory sources. In the present work, a deep well vertical turbine pump experienced extremely high vibrations for a long time although it still being new. It hasn't been in operation for over 6 months. The pump system suffers from extremely high vibration levels relative to the rotational speed (1X motor dominant frequency). An efficient strategy was implemented by using well-conceived techniques. The experimental modal analysis confirmed a presence of a natural frequency. Modifications were carried out to overcome resonance. Finite element analysis was done to determine the reed critical frequencies as a powerful tool to identify and mitigate vibration issues. On-site motor balancing was done to remove vibrations due to the residual imbalance. Results revealed decreasing vibration level by about 66% after solving all problems.
Źródło:
Diagnostyka; 2023, 24, 2; art. no. 2023209
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cut Elimination for Extended Sequent Calculi
Autorzy:
Martini, Simone
Masini, Andrea
Zorzi, Margherita
Powiązania:
https://bibliotekanauki.pl/articles/43182562.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
proof theory
sequent calculus
cut elimination
modal logic
2-sequents
Opis:
We present a syntactical cut-elimination proof for an extended sequent calculus covering the classical modal logics in the \(\mathsf{K}\), \(\mathsf{D}\), \(\mathsf{T}\), \(\mathsf{K4}\), \(\mathsf{D4}\) and \(\mathsf{S4}\) spectrum. We design the systems uniformly since they all share the same set of rules. Different logics are obtained by “tuning” a single parameter, namely a constraint on the applicability of the cut rule and on the (left and right, respectively) rules for \(\Box\) and \(\Diamond\). Starting points for this research are 2-sequents and indexed-based calculi (sequents and tableaux). By extending and modifying existing proposals, we show how to achieve a syntactical proof of the cut-elimination theorem that is as close as possible to the one for first-order classical logic. In doing this, we implicitly show how small is the proof-theoretical distance between classical logic and the systems under consideration.
Źródło:
Bulletin of the Section of Logic; 2023, 52, 4; 459-495
0138-0680
2449-836X
Pojawia się w:
Bulletin of the Section of Logic
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of dynamic parameters of a tram wheel parts in a numerical and experimental modal analysis
Autorzy:
Milewicz, Julia
Kołodziejczak, Krzysztof
Nowakowski, Tomasz
Szymański, Grzegorz M.
Powiązania:
https://bibliotekanauki.pl/articles/27311809.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
rail vehicles
modal analysis
simulation
modes extraction
pojazdy szynowe
analiza modalna
symulacja
ekstrakcja trybów
Opis:
The analysis of dynamic parameters finds effective application in processes related to the assessment of the technical condition of machines. Mass transport vehicles are particularly sensitive to maintaining an appropriate level of traffic safety through relevant design and diagnostics. The combination of numerical and experimental methods increases the efficiency of modal properties investigations, which can be used as diagnostic parameters. During the research, the authors performed a numerical model of a system composed of a rim and an inner disc of a wheel fitted in a Konstal 105Na tram, widely used in many polish cities and frequently subjected to repair and renovation processes. The Time Response analysis in SOLIDWORKS (also called Modal Time History) was then conducted, resulting in obtaining information about object vibration response in time domain to the impulsive excitation at given points. These signals were then processed in MATLAB aiming at determining the frequencies of natural vibration and damping ratios. The processing parameters in MATLAB were corresponding to the analysis settings of the experimental measurement, carried out within the BK Connect environment, with an impact modal hammer and piezoelectric transducers. When analyzing the experimental measurements, the authors applied Fast Fourier Transformation, Frequency Response Function and Complex Mode Indicator Function (the theoretical basis of which and practical sense of application were also presented in the paper). Finally, the results of the experiment were compared with simulation outcomes. This comparison allowed the obtainment of frequency characteristics of the vibration response to the impact and the determination of the dynamic parameters of the actual object. Six frequencies of natural vibrations were determined in the frequency range of 0 to 3000 Hz, as well as their damping ratios and autocorrelation indicators between modes. Similarities and potential sources of differences between the numerical and the experimental results were identified and explained, followed by conclusions on the practical application of the presented research methodology in the industry.
Źródło:
Archives of Transport; 2023, 67, 3; 119--137
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic analysis of a steel-concrete railway bridges of Langer type under the influence of a moving load
Analiza dynamiczna stalowo-betonowego mostu kolejowego typu Langera pod wpływem obciążenia ruchomego
Autorzy:
Szaniec, Waldemar
Radoń, Urszula
Bekő, Adrián
Powiązania:
https://bibliotekanauki.pl/articles/27314913.pdf
Data publikacji:
2023
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
modal analysis
Newmark method
FEM model
moving load
steel-concrete railway bridges of Langer type
analiza modalna
metoda Newmarka
model MES
obciążenie ruchome
stalowo-betonowe mosty kolejowe typu Langera
Opis:
The studying the dynamic response of steel-concrete railway bridges of Langer type is huge importance of ensuring the safety of such structures under high-speed train loads. Numerical simulations at the design stage require knowledge of the modal characteristics: natural frequencies, shapes and damping. In addition, in the dynamics of railway bridges subjected to high-speed trains, it is important to check the impact of dynamic effects on the ultimate and serviceability limit states. As part of the investigations displacements and accelerations of selected measurement points arising from driving the test rolling stock are analyzed. In the first stage, calculations of the eigenvalues and the corresponding eigenvectors were carried out in the Robot program for two variants of mass description (distributed and discrete). In the second stage, dynamic train passages for various vehicle speeds were examined in terms of displacements and accelerations of measurement points by using the authors’ program MES3D.
Badanie odpowiedzi dynamicznej stalowo-betonowych mostów kolejowych typu Langera ma ogromne znaczenie dla zapewnienia bezpieczeństwa takich obiektów pod obciążeniem pociągów dużych prędkości. Symulacje numeryczne na etapie projektowania wymagają znajomości charakterystyk modalnych: częstotliwości drgań własnych, form i tłumienia. Dodatkowo w dynamice mostów kolejowych poddanych działaniu pociągów szybkobieżnych istotne jest sprawdzenie wpływu efektów dynamicznych na stany graniczne nośności i użytkowalności. W ramach badań analizowano przemieszczenia i przyspieszenia wybranych punktów pomiarowych powstałych od jazdy taborem próbnym. W pierwszym etapie przeprowadzono obliczenia wartości własnych i odpowiadających im wektorów własnych w programie Robot dla dwóch wariantów opisu masy (rozłożonej i dyskretnej). W drugim etapie zbadano przebiegi dynamiczne dla różnych prędkości pociągów pod kątem przemieszczeń i przyspieszeń punktów pomiarowych za pomocą autorskiego programu MES3D.
Źródło:
Structure and Environment; 2023, 15, 3; 147--158
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of dam–rock foundation interaction modeling on the modal ratio-related quantity of Beni Behdel and `El Mefrouch multi-arch dams
Autorzy:
Berrabah, Amina Tahar
Attia, Amina
Habib, Daoudi Mohammed
Ouzandja, Djamel
Powiązania:
https://bibliotekanauki.pl/articles/2233102.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
related quantities
modal behavior
dam–rock foundation interaction
ANSYS code
Opis:
Using the Beni Behdel dam and the El Mefrouch dam as example studies, this paper intends to clearly demonstrate how modeling of the interactions between rock foundations and dams impacts the modal behavior of these two multi-arch dams. The uniqueness of this study is that the modal behavior of each dam is represented in terms of related parameters (period, participation factor, ratio, and effective mass), and more precisely in terms of ratio (defined as the ratio between the participation factor of the mode i and the maximum participation factor), as opposed to other works that have expressed this behavior in terms of frequency. In this article, stiff rock foundation, massless rock foundation, and massed rock foundation are the three methods used to simulate dynamic interactions. The investigated dams are three-dimensionally simulated using the ANSYS finite elements code. The modeling of the rock foundation–dam interaction has an effect on the fundamental mode value, its location, and the related parameters, according to the results. Furthermore, it is found that the upstream–downstream direction is not always the most important direction for dams and that interaction modeling influences the resonance bandwidth, which affects the forecast of the resonance phenomenon.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 3; 452--459
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of the COVID-19 travel restrictions on metropolises mobility: empirical evidence from the Tri-City metropolis (Poland)
Wpływ ograniczeń podróży związanych z COVID-19 na mobilność metropolitalną: dowody empiryczne z metropolii trójmiejskiej (Polska)
Autorzy:
Grzelec, Krzysztof
Hebel, Katarzyna
Okraszewska, Romanika
Wyszomirski, Olgierd
Powiązania:
https://bibliotekanauki.pl/articles/34656111.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Gdański. Komisja Geografii Komunikacji Polskiego Towarzystwa Geograficznego
Tematy:
COVID-19 epidemic
lockdown
travel restrictions
transport mobility
modal shift
epidemia COVID-19
ograniczenia podróży
mobilność transportowa
przesunięcie modalne
Opis:
This paper aims to assess changes in mobility and modal shift caused by COVID-19 travel restrictions among the residents of Gdańsk Bay Metropolis (Poland). Measurement’s moments were assumed in periods differing in the level of restrictions. The computer-assisted telephone interview (CATI) was carried out in November and December 2020. The results did not confirm the expected modal shift. However, significant changes in the number of trips between periods were observed. Restrictions in the first period of the pandemic resulted in a greater decrease in mobility than the restrictions at the end of the year. Moreover, significant associations were found between transport behaviour and place of residence. Nevertheless, possible negative changes in the modal split after the pandemic ends should be counteracted by improving the quality of public transport services. As the most important attributes of public transport attracting passengers after the pandemic respondents recognized: high frequency of vehicles, low cost of travel, not overcrowded vehicles. However, some residents declared they will not use public transport regardless of service improvements. Consequently, to meet the objectives of sustainable mobility policy, it can be necessary to increase the share in the modal split of other sustainable modes of travel.
Źródło:
Prace Komisji Geografii Komunikacji PTG; 2023, 26(1); 52-68
1426-5915
2543-859X
Pojawia się w:
Prace Komisji Geografii Komunikacji PTG
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental dynamic damage assessment of PUFJ protected brick infilled RC building during successive shake table tests
Autorzy:
Kwiecień, Arkadiusz
Rakicevic, Zoran
Chełmecki, Jarosław
Bogdanovic, Aleksandra
Tekieli, Marcin
Hojdys, Łukasz
Gams, Matija
Krajewski, Piotr
Manojlovski, Filip
Soklarovski, Antonio
Halici, Omer Faruk
Rousakis, Theodoros
Vanian, Vachan
Powiązania:
https://bibliotekanauki.pl/articles/27311429.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
shake table
earthquake
dynamic characteristics
modal hammer
DIC
digital image correlation
stół wstrząsowy
trzęsienie ziemi
charakterystyka dynamiczna
młotek modalny
cyfrowa korelacja obrazów
Opis:
It is highly important to determine eigenvalues before and after certain extreme events that may cause damage accumulation, such as earthquake, blasts and mining or seismic tests on research models. Unique experiment design and shake table testing was performed to investigate seismic performance of a 3D RC building model with infill walls and advanced protection with polyurethane-based joints and fiber polymer reinforced light and emergency jackets. For the purpose of wider experimental activities, three methods for determination of the dynamic characteristics were used during multiple successive shake table tests following a dynamic pushover approach, and they are presented in detail. They are: inertance function through impact hammer tests, standard Fourier transformation of measured acceleration time history and digital image correlation. The expected differences in the results are related to the type and intensity of excitation used, the involvement of materials with different mechanical and physical properties, and with the different rate and extent of damage accumulation, as well as to local or global measurements. Y et, all methods lead to reliable results when a consistent methodology is being used, that takes into account locality or globality of measurements, leaving a choice for the most suitable one, depending on the site conditions. The inertance function method presented manifested its high efficiency in analysis of dynamic properties of large-scale structures and in monitoring of their changes caused by the damage and repair process. It offers quite a wide range of useful information, does not require very expensive equipment and its transportation cost is negligible. This method seems to be a proper diagnostic tool for simple experimental modal analysis of real structures and their structural elements, where detection of changes in the structural condition and in dynamic properties is required, also as a non-destructive testing and monitoring method. Digital image correlation proved to be a promising non-contact tool, strongly supporting the conventional instrumentation of shake table testing, while the Fourier transformation was used as a benchmark method yielding the most reliable results.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 3; art. no. e144940
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research on the vibration characteristics of canvas and primed canvas of paintings
Autorzy:
Gao, Yulong
Ziegler, Pascal
Heinemann, Carolin
Hartlieb, Eva
Eberhard, Peter
Powiązania:
https://bibliotekanauki.pl/articles/27309889.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
canvas
primer
vibration characteristics
experimental modal analysis
climate compensation
charakterystyka wibracji
eksperymentalna analiza modalna
kompensacja klimatyczna
Opis:
Paintings inevitably bear severe mechanical loads during transportation.Understanding the dynamic characteristics of paintings helps to avoid damage during transportation and to effectively slow down their aging.In this contribution, the vibration characteristics of canvas and primed canvas of paintings and their influencing factors are studied experimentally.For this reason, two dummy paintings with canvas in a common orientation and a tilted orientation are investigated, and an experimental setup using an excitation mechanism and a laser Doppler vibrometer is developed.In order to avoid changes of the modal parameters related to humidity or temperature, all experiments were conducted in a climate box.The modal parameters of dummy paintings are identified by means of experimental modal analysis.Also, the difference in modal properties of the two dummy paintings before and after applying the primer are compared.The identified modal parameters are used to reconstruct their eigenmodes.From the identified modal parameters a numerical model is derived, which is then compared to measurements.The comparison shows a good agreement, hence is a hint for the correctness of assuming a modal structure and the quality of the modal parameter identification.Lastly, with the help of the climate box, the influences of humidity and temperature on the eigenfrequencies of dummy paintings are studied.
Źródło:
Archive of Mechanical Engineering; 2023, LXX, 3; 333--350
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractional-Valued Modal Logic and Soft Bilateralism
Autorzy:
Piazza, Mario
Pulcini, Gabriele
Tesi, Matteo
Powiązania:
https://bibliotekanauki.pl/articles/43181839.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
modal logic
general proof theory (including proof-theoretic semantics)
many-valued logics
Opis:
In a recent paper, under the auspices of an unorthodox variety of bilateralism, we introduced a new kind of proof-theoretic semantics for the base modal logic \(\mathbf{K}\), whose values lie in the closed interval \([0,1]\) of rational numbers [14]. In this paper, after clarifying our conception of bilateralism – dubbed “soft bilateralism” – we generalize the fractional method to encompass extensions and weakenings of \(\mathbf{K}\). Specifically, we introduce well-behaved hypersequent calculi for the deontic logic \(\mathbf{D}\) and the non-normal modal logics \(\mathbf{E}\) and \(\mathbf{M}\) and thoroughly investigate their structural properties.
Źródło:
Bulletin of the Section of Logic; 2023, 52, 3; 275-299
0138-0680
2449-836X
Pojawia się w:
Bulletin of the Section of Logic
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification based on a finite element model of an impact force occurring on a composite structure
Autorzy:
El-Bakari, Abdelali
Khamlichi, Abdellatif
Hanafi, Issam
Powiązania:
https://bibliotekanauki.pl/articles/27312394.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
analiza modalna
siła uderzenia
struktura złożona
inverse problem
modal analysis
identification
impact force
composite structure
Opis:
Based on the inverse approach and the finite element method, the quality of a reconstructed signal is discussed in this work. The responses caused by a distributed impact on a portion of a composite structure can be recovered using dynamic analysis. The structure is thought to be complex and made up of two different-sized plates made of two different materials. The robustness of the inversion method was studied, as well as the sensitivity of the numerical method compared to modal truncation and sampling of the frequency response function (FRF). Once the FRF had been identified, regularized deconvolution as per generalized singular value decomposition was used to reconstruct the impact signal characteristics. It was revealed that only one mode is required to reconstruct the impact signal.
Źródło:
International Journal of Applied Mechanics and Engineering; 2023, 28, 1; 23--36
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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