Wyniki wyszukiwania - BazTech

1

Recent developments in pullout behaviors and tensile properties of ultra-high-performance concrete reinforced with steel fiber

Wu Hansong, Zang Zhishu, Deng Shiyi, Shen Aiqin, Cai Yanxia, Ren Guiping, Pan Hongmei

Archives of Civil and Mechanical Engineering

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2023

|

Vol. 23, no. 3

art. no. e216, 2023

EN

Ultra-high-performance concrete (UHPC) has gained significant attention as a construction material owing to its exceptional mechanical properties and durability. Steel fibers are widely utilized as a reinforcement material for UHPC. Achieving excellent bond and tensile performances is considered to be a predominant issue for the utilization of steel fiber reinforcement. This comprehensive review presents recent research progress on the bond and tensile properties of steel-fiber-reinforced UHPC. First, an overview of the experimental methods for evaluating pullout and tensile performance is provided. Subsequently, the factors influencing these properties are discussed in detail. The review then comprehensively examines several analytical models for steel-fiber-reinforced UHPC, ranging from traditional approaches to innovative methods such as artificial neural network models, genetic algorithms, deep learning methods, inverse analysis, and micromechanical damage models. Furthermore, the correlations between pullout behavior, tensile performance, and flexural strength are explored in detail. Finally, the review addresses essential considerations and summarizes various modification techniques for improving the pullout and tensile performances, including physical and chemical methods of modifying the steel fiber surface and UHPC matrix. This review serves as a valuable reference for researchers and engineers in relevant fields, promoting further research and application of steel fiber-reinforced UHPC.

2

Classifying Speech Acts in Political Communication: A Transformer-based Approach with Weak Supervision and Active Learning

Schmidt Klaus, Niekler Andreas, Kantner Cathleen, Burghardt Manuel

Annals of Computer Science and Information Systems

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2023

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Vol. 35

739--748

EN

We present a study on the automatic classification of speech acts in the domain of political communication, based on J. R. Searle's classification of illocutionary acts. Our research involves creating a dataset using the US State of the Union corpus and the UN General Debate corpus (UNGD) as data sources. To overcome limited labeled data, we employ a combination of weak supervision and active learning techniques for dataset creation and model training. Through various experiments, we investigate the influence of external and internal factors on speech act classification. In addition, we discuss the potential for further analysis of speech act usage, using the trained model on the UNGD corpus. The findings demonstrate the effectiveness of Transformer-based models for automatic speech act classification, highlight the benefits of weak supervision and active learning for dataset creation and model training, and underscore the potential for large-scale statistical analysis of speech act usage in the domain of political communication.

3

Analysis of the Impact of Data Augmentation on the Performance of Deep Learning Models in Multispectral Food Authenticity Identification

Zhang Yaru, Yilmaz Arif, Popa Mirela, Brewster Christopher

Annals of Computer Science and Information Systems

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2023

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Vol. 35

823--832

EN

Food authenticity is a significant concern in the meat industry, demanding effective detection methods. This study explores the use of multispectral imaging (MSI) and deep learning for meat adulteration detection. We evaluate different deep learning models using transfer learning and preprocessing techniques in a multi-level adulteration classification task. In addition, we propose a novel approach called one-band mixed augmentation for band selection in MSI data, which outperforms traditional reflectance-based feature selection and enhances model robustness. Furthermore, employing the nine-crop approach for dataset augmentation improved the accuracy from 0.63 to 0.74 for DenseNet201 model without transfer learning. This research contributes to advancing food safety assessment practices and provides insights into the application of deep learning for preventing food adulteration. The proposed one-band mixed augmentation approach offers a novel strategy for handling band selection challenges in MSI data analysis.

4

An Enhancement of Reinforcement Learning by Scheduling with Learning Effects

Rudek Radosław

Annals of Computer Science and Information Systems

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2023

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Vol. 35

689--697

EN

This paper present results, which reveal that approaches obtained for scheduling problems with learning effects can be successfully used to improve the quality of machine learning methods. It is illustrated by modelling some aspects of Q-learning agents as scheduling problems with the learning effect, and constructing sequencing and dispatching algorithms, which take into account the existence of learning. Their application to determine the sequence of tasks processed by Q-learning agents can visibly speed up their convergence to an optimal strategy. Furthermore, we show that a dispatch of tasks according to the longest processing time algorithm for parallel computing can be replaced by a more efficient procedure, if agents can learn. The numerical analysis reveals that our approach is efficient, robust and only marginally dependents on a learning model and an accurate approximation of task processing times.

5

Dyspersja hydrodynamiczna w procesie wypierania gazów w rdzeniach skalnych

Blicharski Jacek, Stopa Jerzy

Przemysł Chemiczny

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2022

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T. 101, nr 1

50--54

PL

Przedstawiono wyniki badań laboratoryjnych wypierania azotu metanem w rdzeniach skalnych. Zaprezentowano model matematyczny eksperymentu oraz wyznaczono wartości współczynników dyfuzji molekularnej i dyspersji mechanicznej. Zaobserwowano zależność współczynnika dyspersji mechanicznej od ciśnienia w zakresie ciśnień 1-6 bar.

EN

Expts. of N2 displacement with MeH in rock cores were carried out on the laboratory test stand. The math. model of the expt. was presented and the coeff. of mol. diffusion and mech. dispersion were detd. The dependence of the mech. dispersion coeff. on the pressure in the range of 1-6 bar was obsd.

6

The influences of source intensity and meteorological factors on sulfur dioxide and nitrogen oxides based on the path analysis mode

Guo Chen-Lin, Zhang Jing, Zhou Qian Shuang, Ma Yong

Environment Protection Engineering

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2022

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Vol. 48, nr 4

51--65

EN

With rapid economic development and industrialization, air pollution is becoming a critical global issue affecting health. Sulfur dioxide and nitrogen oxides are the major contributors to acid rain and the key indicators for evaluating atmospheric pollution. And source intensity and meteorological factors are the main ways to influence the concentrations of sulfur dioxide and nitrogen oxides. Thus, to investigate the specific effects of source intensity, temperature, humidity, wind speed and atmospheric pressure on SO2 and NOx, the path analysis method was used for the model. The results showed that Source intensity significantly affects the concentrations of SO2and NO2. For both NO2 and SO2, the source intensity accounted for around 40%. Meteorological factors have very limited effects on the concentrations of SO2and NO2. The effects of the meteorological factors on air pollutants are specific as differences in material properties. Humidity significantly affects the concentration of SO2while temperature, humidity and wind speed have significantly affected the concentration of NO2.

7

Rule-based approximation of black-box classifiers for tabular data to generate global and local explanations

Maszczyk Cezary, Kozielski Michal, Sikora Marek

Annals of Computer Science and Information Systems

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2022

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Vol. 30

89--92

EN

The need to understand the decision bases of artificial intelligence methods is becoming widespread. One method to obtain explanations of machine learning models and their decisions is the approximation of a complex model treated as a black box by an interpretable rule-based model. Such an approach allows detailed and understandable explanations to be generated from the elementary conditions contained in the rule premises. However, there is a lack of research on the evaluation of such an approximation and the influence of the parameters of the rule-based approximator. In this work, a rule-based approximation of complex classifier for tabular data is evaluated. Moreover, it was investigated how selected measures of rule quality affect the approximation. The obtained results show what quality of approximation can be expected and indicate which measure of rule quality is worth using in such application.

8

Intuitionistic fuzzy model of the Hungarian algorithm for the salesman problem and software analysis of a shipping company example

Traneva Velichka, Mavrov Deyan, Tranev Stoyan

Annals of Computer Science and Information Systems

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2022

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Vol. 30

383--386

EN

Here we propose for the first time a temporal intuitionistic fuzzy extension of the Hungarian method for solving the Travelling Salesman Problem (TIFHA-TSP) based on intuitionistic fuzzy logic and index matrices theories. The time for passing a given route between the settlements depends on different factors. The expert approach is used to determine the intuitionistic fuzzy time values for passing the routes between the settlements. The rating coefficients of the experts take the times into account. We are also developing an application for the algorithm's provision to use it on a real case of TIFHA-TSP.

9

Wizualne odwzorowanie nowoczesnych fasad szklanych. Część 1

Jakica Nebojsa, Kragh Mikkel, Besse Gregoire

Świat Szkła

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2021

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R. 26, nr 4

45--48

10

Analytical Models for Optimal Design of a Trapezoidal Composite Channel Cross-Section

Pourbakhshian Somayyeh, Pouraminian Majid

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 1

118--138

EN

In this paper, several analytical models are presented for the optimal design of a trapezoidal composite channel cross-section. The objective function is the cost function per unit length of the channel, which includes the excavation and lining costs. To define the system, design variables including channel depth, channel width, side slopes, freeboard, and roughness coefficients were used. The constraints include Manning’s equation, flow velocity, Froude number, and water surface width. The Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm was used to solve the optimization problem. The results are presented in three parts; in the first part, the optimal values of the design variables and the objective function are presented in different discharges. In the second part, the relationship between cost and design variables in different discharges is presented in the form of conceptual and analytical models and mathematical functions. Finally, in the third part, the changes in the design variables and cost function are presented as a graph based on the discharge variations. Results indicate that the cost increases with increasing water depth, left side slope, equivalent roughness coefficient, and freeboard.

11

Analytical models tracing deformation of wood-framed walls during vertical transport

Malesza Jarosław, Miedziałowski Czesław

Archives of Civil Engineering

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2021

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Vol. 67, nr 1

131--146

EN

Vertical transport of wall-panels is a part of the prefabrication process of wood-framed buildings. The total dead weight of a wall is suspended on several lifting slings, pointwise clasping the top plate of the wall. This indicates, that all the weight of a wall is cumulated in sheathing-to-framing fasteners, usually staples. This article presents experimental investigations and analytical models evaluated for the description of light wood-framed walls in the process of lifting. Three different models cover the analytical approach: a model of a simple beam on elastic supports (BSS), a model of assembled beams (ACBS), three-dimensional (3D) spatial FE model of the wall (WFEM). Board-to-beam joint material parameters are determined on the base of experimental results. These connections are converted into two variants in the form of spring elements for 2D analysis, and beam elements for 3D analysis. The numerical results exhibit that the proposed models may correctly represent behavior of a real wall in lifting, applying elastic materials parameters.

PL

Transport pionowy tarcz ściennych jest częścią procesu prefabrykacji szkieletowych budynków drewnianych. Cały ciężar ściany spoczywa wówczas na kilku zawiesiach zaplecionych wokół górnej belki ściany. Oznacza to, iż obciążenie to kumuluje się w łącznikach (zszywkach) łączących górną belkę z poszyciem ściany. W artykule opisano badania doświadczalne oraz zaproponowano modele obliczeniowe ścian poddanych odkształceniom w procesie podnoszenia. W badaniach szczególną uwagę zwrócono na miejsca zaczepienia zawiesi i ich wpływ na pracę statyczną elementów konstrukcji. Dodatkowym efektem badań był wpływ wad materiałowych na zachowanie się konstrukcji. Badania eksperymentalne prowadzono do zniszczenia, które dla tarcz bez otworów i bez widocznych wad materiałowych obserwowano przy obciążeniu około P=50kN, natomiast w przypadku tarczy z wadami materiałowymi obciążenie niszczące osiągnęło wartość P=34kN. Dzięki badaniom uzyskano obraz deformacji górnego rygla oraz łączników poszycia i konstrukcji drewnianej w szczególności w obszarze bezpośrednich oddziaływań sił pochodzących od zawiesi. W artykule zaproponowano trzy modele obliczeniowe do oceny deformacji ścian: model belki na sprężystych podporach (BSS), model belek złożonych z połączeniami w postaci sprężyn (ACBS) i przestrzenny model MES (WFEM). W modelach belkowych połączenia opisano za pomocą elementów sprężynowych, a w modelu 3D za pomocą elementów belkowych. Parametry materiałowe użyte w opisie połączeń określono na podstawie badań złączy na zszywki. Analizy teoretyczne wykazała bardzo dobrą zbieżność modeli teoretycznych z badaniami doświadczalnymi w zakresie obciążeń P od około 8kN do 20kN. Ten zakres obciążeń określono na podstawie rzeczywistych obciążeń wynikających z ciężarów podnoszonych elementów, ponadto wielkości tych obciążeń wynikają z liniowo-sprężystej fazy pracy łącznika w połączeniu płyty poszycia z konstrukcją. Obciążenia powyżej P=20,00 kN wykazują w analizach modelowych większą sztywność niż to wynika z rezultatów badań doświadczalnych tarcz. Zaproponowany nowy, złożony model belkowy (ACBS) z dużą dokładnością odwzorowuje rzeczywistą pracę konstrukcji ścian na obciążenia ciężarem własnym w procesie podnoszenia. Może być zastosowany do ścian o różnej długości i konfiguracji otworów. Model ten w łatwy sposób może służyć ocenie wytężenia łączników, a w szczególności określeniu takiego rozstawu zawiesi, w którym zagwarantowane jest bezpieczne przenoszenie ściany. Jako kryterium bezpieczeństwa można, w zależności od wymagań, przyjąć: dopuszczalną nośność, dopuszczalną deformację lub dopuszczalną podatność łącznika.

12

Management of technological process optimisation

Lypchuk Vasyl, Dmytriv Vasyl

Engineering Management in Production and Services

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2020

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Vol. 12, no. 3

103--115

EN

The research aims to characterise the optimisation of a technological process depending on the main time parameters for production. The optimisation does not require to correct technical parameters of a system, but rather the organisational and managerial factors of the technological process. The workload is taken as an evaluation criterion, which factors in the probability distribution of time characteristics of computer process operations. Time characteristics that represent the performance of an operation influence the workloads of an operator and equipment, determining the productivity of the technological process. Analytical models were developed for the operational control of a production line efficiency considering the probability–statistical parameters pertaining to the performance of operations and technological equipment peculiarities. The article presents research results, which characterise the dependence of a production line efficiency on the type of equipment, and the duration of preparatory and final operations considering their probability. Under an optimal workload of the operator, the duration of the complete program changes linearly, regardless of the time required for the performance of operations by a computer without the involvement of the operator, and depending on the type of equipment. A managerial decision can be optimal under the condition that the factor of technological process efficiency (K_TP) tends to max. The developed method of analytical determination can be used to calculate the workload of both an operator and technological equipment. The calculations of the duration of a production line operation resulted in the methodology for the consideration of probability characteristics pertaining to the time distribution of the period required to perform operations, which influences the unequal efficiency of the production line. The probabilistic character of time distribution related to intervals of performed operations serves as a parameter in the management of technological process optimisation, which can be achieved using simulators of technological processes optimised in terms of their efficiency.

13

BIM w budownictwie – parametryczne modele w prefabrykacji

Salamak Marek, Grzesiak Szymon

Materiały Budowlane

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2019

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nr 9

26--29

14

Analytical dynamic model of coefficient of friction of air pipeline under pressure

Dmytriv Vasyl, Dmytriv Ihor, Horodetskyy Ivan, Dmytriv Taras

Diagnostyka

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2019

|

Vol. 20, No. 4

89--94

EN

To transport of the air in the pipeline, an analytical model is developed that takes into account the gas velocity, its kinematic and dynamic characteristics - density, viscosity depending on the pressure in a given space of the pipeline. The analytical model makes it possible to calculate the coefficient of friction of gas transportation in the pipeline at intervals of the absolute pressure from 220 to 2 kPa and M < 1 Mach numbers, depending on the diameter and length of the pipeline and physical and technological characteristics of the gas. The K1* aspect ratio is proposed, which characterizes in time the ratio of the dynamic force of movement of gas to the static pressure related to the diameter of the pipeline. The coefficient of air friction was modeled according to the vacuum pressure as a parameter of density and air flow. Air flow was taken from 1.917·10-3 m 3/s to 44.5·10-3 m 3/s respectively, diameters from 0.030 to 0.070 m and Mach number was M = 0.005-0.13. At the vacuum and excess pressures with increasing of Reynolds number and decreasing of Mach number the gas friction coefficient increased linearly. According to the simulation results as the pressure loss and the diameter of the pipeline are increased the friction coefficient increased as well. Analogically, at the vacuum metric pressure when the pressure loss and the diameter of the pipeline are increased the friction coefficient increased. At the pipeline internal diameters of 22, 30, 36 mm accordingly for pressure losses from 2 to 14 kPa the coefficient of air friction varies from 0.006 to 54.527 respectively.

15

Developing a model and validating an instrument for measuring the adoption and utilisation of mobile government services adoption in Saudi Arabia

Alonazi Mohammed, Beloff Natalia, White Martin

Annals of Computer Science and Information Systems

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2019

|

Vol. 18

633--637

EN

Many governments worldwide are taking advantage of the latest developments in mobile technology to take the digital delivery of government information and services (e-government) to their citizens a stage further. Accessing government information and services via a mobile device is known as m-government, a system designed to serve citizens, companies and government agencies alike. M-government also has unique advantages over e-government, not least enabling users to access government services at any time and from any location. This paper presents a pilot study of the MGAUM model that was developed to analyze factors influencing the adoption rate of m-government services in Saudi Arabia. With the aim of validating a survey instrument with which to conduct the main study in Saudi Arabia, a pilot survey instrument was developed and modified by using previous instruments from research into both e-government and m-government. This pilot questionnaire was distributed to 71 Saudi citizens in the UK, and the final sample was 58 valid responses. The results of this pilot study reveal that all items in the survey instrument were reliable and valid within the range of acceptable academic research and suitable for use in the main study. The results of this pilot study were analyzed using SPSS.

16

Automation of analytical model construction for intellectual superstructure in next generation networks

Pustovyi B.

Zeszyty Naukowe Wydziału Elektroniki i Informatyki Politechniki Koszalińskiej

|

2018

|

Nr 12

49--60

EN

The software is suggested for automation of analytical model construction for intellectual superstructure in next generation networks. The software is designed for automation of the system probable states calculation, the construction of the Markov process transition graph and generation of equations system to determine stationary probabilities. An example of analytical model construction is represented for intellectual superstructure with centralized control principle.

PL

Zaproponowano oprogramowanie do zautomatyzowania analitycznego modelu budowy intelektualnej nadbudowy w sieciach następnej generacji. Oprogramowanie jest przeznaczone do automatyzacji obliczania stanów prawdopodobieństwa systemu, konstrukcji wykresu przejścia procesu Markowa i generowania układu równań w celu ustalenia stacjonarnych prawdopodobieństw. Przykład konstrukcji modelu analitycznego jest reprezentowany dla nadbudowy intelektualnej z zasadą scentralizowanej kontroli.

17

Analiza porównawcza mocy i sprawności układu kogeneracyjnego turbiny gazowej i parowej

Chinhenha A., Mindykowski J.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2018

|

nr 103

26--42

PL

Przedmiotem pracy są badania symulacyjne i analiza wybranych parametrów siłowni pracującej w obiegu gazowo-parowym. Celem pracy jest opracowanie metodyki oceny mocy i sprawności siłowni z turbinami pracującymi w obiegu gazowo-parowym z wykorzystaniem autorskiego modelu analitycznego rozważanej instalacji. Uzyskane na podstawie przyjętego modelu szacunkowe wartości mocy i sprawności siłowni porównano z wynikami uzyskanymi podczas testów odbiorczych przykładowej instalacji, przeprowadzonych przez jedno z wiodących konsorcjów, działających w obszarze systemów wytwarzania energii (SIEMENS AG. Power Generation Group).

EN

This paper deals with analysis and simulation research of selected parameters of combined cycle plant. Presented work is focused on elaboration of the evaluation methodology of power and efficiency of combined cycle plant based on the author’s analytical model of considered installation. The estimated values of power and efficiency obtained on the basis of the elaborated model have been compared with the results obtained during the final tests of the exemplary installations carried out by the one of the leading producers of the systems in the power generation field.

18

Koncepcja modelu analitycznego chmury obliczeniowej

Hanczewski S., Weissenberg M.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2018

|

nr 8-9

835--838, CD

PL

Systemy, które oferują usługi chmury obliczeniowej są jednymi z najszybciej rozwijających się obszarów ICT (ang. Information and Communication Technologies). Oferowany szeroki wachlarz usług oraz rosnąca liczba użytkowników sprawia, że konieczne stało się opracowanie odpowiednich metod analitycznych umożliwiajżcych analizę takich systemów. W artykule zaproponowano koncepcję modelu analitycznego opracowanego w oparciu o model idealnej wiązki niepełnodostępnej.

EN

Cloud computing is among the fastest-developing areas of Information and Communication Technologies (ICT). The increasing number of users and the number of services offered by the network makes it necessary to develop new methods of network modeling and analysis. The paper presents a concept of model of cloud computing based on the Erlang’s Ideal Grading (EIG) model.

19

Analityczny model plastrów w sieciach 5G

Hanczewski S., Weissenberg J.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2018

|

nr 8-9

634--639, CD

PL

Sieci 5G mają być w pełni szerokopasmowymi sieciami dostępowymi. Zasoby sieci mają być dzielone na plastry. Koncepcja plastrów opiera się na dwóch znanych rozwiązaniach: wirtualizacji i sieci programowych SDN. Ponieważ efektywne wykorzystanie zasobów interfejsu radiowego jest kluczowe dla realizacji oferowanych usług na odpowiednim poziomi QoS, konieczne jest opracowanie modelu analitycznego sieci 5G. Model taki mógłby być narzędziem wspomagajaącym pracę inżyniera odpowiedzialnego za projektowanie i utrzymanie sieci 5G. Artykuł zawiera propozycję właśnie takiego modelu.

EN

5G networks are to be fully broadband access networks, in which network resources are to be divided in to slices. The concept of slice is based on virtualisation and Software Define Network. Since the effective use of radio interface resources is crucial for the implementation of the services offered at the appropriate QoS level, it is necessary to develop an analytical model of 5G networks. The article contains a proposal of an analytical model, which in the Authors view can become a tool supporting an engineers responsible for designing and maintaining the 5G networks.

20

Praca podkładu kolejowego jako konstrukcji o zmiennym przekroju poprzecznym - zagadnienie ekwiwalentnego przekroju

Czyczuła W., Błaszkiewicz D., Urbanek M.

Przegląd Komunikacyjny

|

2018

|

R. 73, nr 6

2--6

PL

W pracy przedstawiono analizę pracy podkładu jako konstrukcji o zmiennym przekroju oraz sposobu wyznaczenia ekwiwalentnego przekroju, stałego na długości, którego zastosowanie, dawałby zbliżone kształt linii ugięcia i naprężeń zginających w odniesieniu do rzeczywistego, zmiennego przekroju poprzecznego. Przy wykorzystaniu modelu analitycznego oraz numerycznego określono przemieszczenia pionowe oraz naprężenia dla dwóch typów podkładu PS-94 i PS-08. Porównanie metod pozwala na wyznaczenie ekwiwalent-nego momentu bezwładności do obliczeń analitycznych, zwłaszcza dynamicznych.

EN

The article presents an analysis of the work of a sleeper as a construction with variable section, and of the method of determining an equivalent section, constant throughout the length, the utilisation of which would have similar shapes of deflection and bending stress lines in relation to the real, variable cross section. Using an analytical and a numerical model, vertical displacements and stresses for two types of sleepers - PS-94 and PS-08 - were determined. The comparison of the methods allows for calculating an equivalent moment of inertia for analytical calculations, specifically the dynamie ones.