Wyniki wyszukiwania - BazTech

1

Examination of different models of troposphere delays in SBAS positioning in aerial navigation

Krasuski Kamil, Kirschenstein Małgorzata

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

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z. 118

123--137

EN

This paper presents the results of a study on the use of different tropospheric correction models in SBAS positioning for air navigation. The paper, in particular, determines the influence of the Saastamoinen troposphere and RTCAMOPS models on the determination of aircraft coordinates and mean coordinate errors in the SBAS positioning method. The study uses real kinematic data from a GPS navigation system recorded by an onboard GNSS satellite receiver as well as SBAS corrections. In the experiment, the authors include SBAS corrections from EGNOS and SDCM augmentation systems. The navigation calculations were performed using RTKLIB v.2.4.3 and Scilab 6.1.1 software. Based on the conducted research, it was found that the difference in aircraft coordinates using different troposphere models can reach up to ±2.14 m. Furthermore, the use of the RTCA-MOPS troposphere model improved the values of mean coordinate errors from 5 to 9% for the GPS+EGNOS solution and from 7 to 12% for the GPS+SDCM solution, respectively. The obtained computational findings confirm the validity of using the RTCA-MOPS troposphere model for SBAS positioning in aerial navigation.

2

Measurement of delay using travel time reliability statistics in an urban outer corridor

Reddy Kanala Teja Vinay Kumar, Challagulla Surya Prakash

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

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z. 114

143--154

EN

Unexpected delay on freeways is the prime cause of dissatisfaction in road users. Increasing traffic, adverse environmental conditions, accidents, time, season, location and many more factors influence travel time and cause delay. There is no direct method to estimate delay. It is calculated from trip time estimates. Thus, it is a very big challenge for transportation professionals to develop a model that accurately estimates the trip time for a trip at a particular time, by a specific mode of transport. Subsequently, the reliability of the delay calculated from those trip time estimates is often doubtful. Further, the measurement of delay using the trip time data is another big thing. This paper is a step toward measuring the delay in an accurate way using travel time reliability measures. The study was conducted on the two modes of public transportation (City bus and Auto) in an urban corridor of length 16.3 km, in Hyderabad city, India. In this study, a license plate survey was conducted for data collection, travel time-based statistical analysis was employed for estimation of trip time and by making use of travel time measures, the delay was measured. The approach was validated graphically to portray its accuracy.

3

Estimation of the necessary length of strengthening the pavement structure in the vicinity of a bus stop on the basis of tests carried out in a selected city

Gardas Przemysław, Sołowczuk Alicja

Roads and Bridges - Drogi i Mosty

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2022

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Vol. 21, no. 1

39--61

EN

The current design guidelines classify the pavement structure depending on the traffic category KR. In the case of bus stops located along a street, the pavement in "the bus stop area" should be designed for a KR one degree higher than the KR determined on the adjoining carriageway. Assessing the condition of the pavement in the area of 100 bus stops located in a selected city the authors noted the different service condition of the pavement along the bus wheel track in the bus stop area. The deformations of the pavement included settlements, ruts and bumps and the pavement distresses included cracks, potholes, patching, damaged curbs and manholes, etc. The horizontal forces were estimated at 19 selected bus stops variously located relative to the nearest intersection. 12 sectors were distinguished along the bus wheel track in the bus stop area and bus drive through times, speed, decelerations and accelerations were measured in these sectors. The results of the measurements were subjected to statistical analyses and the lengths of the intensified impact of the horizontal forces on the pavement and the extended duration of the bus load impact on the pavement were estimated. After the lengths of the sections with intensified horizontal forces and extended time of the impact on the pavement were compared with the locations of pavement deformations and distresses the necessary lengths of pavement strengthening at the bus stops depending on the latter’s location relative to the nearest intersection were determined. The determined lengths of pavement structure strengthening along the zones of approach to and departure from the bus stop can be used also in other cities.

PL

Obowiązujące wytyczne projektowe klasyfikują konstrukcję nawierzchni w zależności od wyznaczonej kategorii ruchu KR. W przypadku przystanków autobusowych, usytuowanych w ciągu ulicy, nawierzchnia „w rejonie przystanku" powinna być zaprojektowana na KR o jeden stopień wyższą niż KR określona na przyległej jezdni. Oceniając stan nawierzchni w rejonie 100 przystanków zlokalizowanych w wybranym mieście, odnotowano różny stan eksploatacyjny nawierzchni wzdłuż śladu autobusu w rejonie przystanku. Do deformacji nawierzchni zaliczono: osiadania, koleiny i garby, a do uszkodzeń: spękania, ubytki, łaty, uszkodzenia krawężników i włazów, itd. Na wybranych 19 przystankach, różnie usytuowanych względem najbliższego skrzyżowania, oszacowano siły poziome. Wzdłuż śladu autobusu w rejonie przystanku wydzielono 12 sektorów, na których wykonano pomiary czasów przejazdu, prędkości, opóźnień i przyspieszeń autobusów. Uzyskane wyniki poddano analizom statystycznym i oszacowano długości wzmożonego oddziaływania sił poziomych na nawierzchnię i wydłużonego czasu oddziaływania na nią obciążenia. Po porównaniu długości wyznaczonych odcinków wzmożonych sił poziomych i wydłużonego czasu oddziaływania na nawierzchnię z miejscami zlokalizowanych deformacji i uszkodzeń oszacowano ko- nieczne długości wzmocnienia nawierzchni na przystankach autobusowych w zależności od ich lokalizacji względem najbliższego skrzyżowania. Uzyskane wyniki długości wzmocnienia konstrukcji nawierzchni wzdłuż dojazdu i odjazdu z przystanku mogą być wykorzystane również w innych miastach.

4

Karakostas fixed point theorem and semilinear neutral differential equations with impulses and nonlocal conditions

Leiva Hugo, Riera Lenin, Lalvay Sebastián

Journal of Mathematics and Applications

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2022

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Vol. 45

107--128

EN

This paper is concerned with the existence and uniqueness of solutions for a semilinear neutral differential equation with impulses and nonlocal conditions. First, we assume that the nonlinear terms are locally Lipschitz, and to achieve the existence of solutions, Karakostas Fixed Point Theorem is applied. After that, under some additional conditions, the uniqueness is proved as well. Next, assuming some bound on the non-linear terms the global existence is proved by applying a generalization of Gronwall inequality for impulsive differential equations. Then, we suppose stronger hypotheses on the nonlinear functions, such as globally Lipschitz conditions, that allow us to appy Banach Fixed Point Theorem to prove the existence and uniqueness of solutions. Finally, we present an example as an application of our method.

5

The use of artificial intelligence methods in the analysis of the results of vehicle braking deceleration tests in the diagnostics of the braking system of a motor vehicle

Dobaj Krzysztof

Journal of civil engineering and transport

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2022

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Vol. 4, No. 1

33--45

EN

The article presents the concept of using an artificial neural network to approximate the parameters describing the vehicle braking process, from the point of view of the application of this method in the diagnostics of the braking system. The artificial neural network of non-linear autoregressionwas used to approximate the dependence of the braking deceleration and the pressure in the braking system. The effectiveness of the neural network was checked depending on the number of neurons in its hidden layerand on the applied learning algorithm. The operation of the neural network was verified based on the actual braking processes of the Skoda Octavia, carried out with different dynamics, with different car weights and different tire inflation pressures. After verifying the neural network, it was used to approximate the braking deceleration values for the pressure values exceeding those present in the input data set. This action allows the analysis of the possibility of the vehicle obtaining a braking deceleration, which qualifies its braking system as efficient. Two concepts of using a neural network to solve this problem were analyzed. Conclusions related to the validity of the development of the discussed methods were drawn.

PL

W artykule przedstawiono koncepcję wykorzystania sztucznej sieci neuronowej do aproksymacji parametrów opisujących proces hamowania pojazdu z punktu widzenia zastosowania tej metody w diagnostyce układu hamulcowego. Do aproksymacji zależności opóźnienia hamowania od ciśnienia w układzie hamulcowym wykorzystano sztuczną sieć neuronową nieliniowej autoregresji. Skuteczność sieci neuronowej sprawdzono w zależności od liczby neuronów w jej warstwie ukrytej oraz zastosowanego algorytmu uczenia. Działanie sieci neuronowej zostało zweryfikowane na podstawie rzeczywistych procesów hamowania Skody Octavii, realizowanych z różną dynamiką, przy różnych masach samochodów i różnych ciśnieniach w oponach. Po weryfikacji sieci neuronowej posłużono się nią do aproksymacji wartości opóźnienia hamowania dla wartości ciśnień przekraczających te występujące w zbiorze danych wejściowych. Działanie to pozwala na analizę możliwości uzyskania przez pojazd opóźnienia hamowania, co kwalifikuje jego układ hamulcowy jako sprawny. Przeanalizowano dwie koncepcje wykorzystania sieci neuronowej do rozwiązania tego problemu. Wyciągnięto wnioski związane z zasadnością rozwoju omawianych metod.

6

Investigation of factors responsible for delays in the execution of adequately funded construction projects

Ogbeifun Edoghogho, Pretorius Jan Harm C.

Engineering Management in Production and Services

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2022

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Vol. 14, no. 1

93--102

EN

Many research efforts have identified funding as a critical factor responsible for the delays in the execution of construction projects. These funding challenges affect the client and contractors alike. However, there is limited information on why delays occur in sponsored projects with evidently adequate funding. Therefore, the study focuses on exploring the factors that impact the cash flow during the execution of sponsored construction projects. The multiple-site case-study method of qualitative research was adopted, involving five universities benefiting from the infrastructure funding provided by a government agency in Nigeria. The Delphi technique was used for data collection and analysis, complemented with interviews. The findings identified six factors causing the delays. They were divided into internal and external factors. The internal factors are faulty contractor selection processes resulting in delays by contractors and the failure to complete appropriate phases of a project. The external factors include the delays in the project management system of the funding agency in terms of inspection, monitoring, evaluation and progress certification. The research identified that the combined effect of internal and external factors negatively impacts the project cash flow, which in turn influences project delivery delays. Therefore, this study recommends improvements in the in-house contractor selection processes and the decentralisation of the project inspection, monitoring and evaluation operations of the funding agency. This will facilitate timely inspection, audit, and progress certification, enabling the early release of the second tranche of the project fund. This will ameliorate the negative effects arising due to low cash flow and associated delays in project delivery.

7

Dynamic performance and stability analysis of an active inerter-based suspension with time-delayed acceleration feedback control

Wang Yong, Jin Xian-Yu, Zhang Yun-Shun, Ding Hu, Chen Li-Qun

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 2

art. no. e140687

EN

An active inerter-based suspension with acceleration feedback control is proposed in this paper, the time delay generated in the controllers and actuators is considered, which constitutes the time-delayed active inerter-based (TDA-IB) suspension. The dynamic equation of the TDA-IB suspension is established and is a neutral type of delay differential equation (NDDE) in which the time delay exists in the highestorder derivative. The stability analysis is conducted by calculating the number of unstable characteristic roots based on the definite integral stability method, the stable and unstable regions are determined. The effect of time delay and feedback gain on the dynamic performance of the TDA-IB suspension under harmonic, random, and shock excitations is studied in detail and compared with the parallel-connected inerterbased (PC-IB) and traditional suspensions. The results show that the TDA-IB suspension is asymptotically stable for smaller feedback gain and time delay, through increasing the feedback gain, the stable regions shrink, and a smaller time delay could cause the system to become unstable. Furthermore, the time delay could regulate the resonance peak around the unsprung mass natural frequency and generate multiple high-frequency resonance peaks. If the time delay is chosen appropriately and falls into the stable range, the TDA-IB suspension could improve the dynamic performance for the suspension stroke and dynamic tire load while having a deterioration for the vehicle body acceleration compared with the PC-IB and traditional suspensions.

8

Open concurrent network communication methods in building distributed web applications

Buchwald Paweł, Dawid Aleksander

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2021

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Vol. 25, No 4

409--418

EN

The attractiveness of real-time multimedia communication as part of an e-learningplatform largely depends on the quality of the telecommunications infrastructure and on theservices that support the exchange of audiovisual data. The research subject of this workis communication between stationary and mobile devices using distributed services such asWeb Real-Time Communication (WebRTC) running in HTML5 compliant web browsers. Thetest connections were carried out in a peer-to-peer architecture over a local wireless WiFinetwork and a mobile network supporting the Long Term Evolution (LTE) standard fordata interchange. Several audiovisual sessions between two clients were analyzed for differentconnection scenarios. Parameters responsible for the transmission quality, such as delay, jitter,packet loss, or the speed of sending and receiving video frames were measured for each scenario.Open audiovisual communication system performance experiments were conducted under realoperating conditions. The obtained results indicated potential applications in the developmentof e-learning websites.

9

Data analysis of the latency in the building with using telecommunication technology

Kawa Bartłomiej, Borkowski Piotr

Przegląd Elektrotechniczny

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2021

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R. 97, nr 2

129--135

EN

This article analyses the latency data that occur during data transmission using the actual telecommunications network in the building. This study is aimed at checking the possibility of using telecommunications as an alternative to the currently used communications in intelligent buildings in order to ultimately move as many elements as possible to the cloud or disperse the system across all building devices. The delay study allows you to determine what delays the system will work with, which is necessary in real-time systems.

PL

Ten artykuł przedstawia analizę danych opóźnień występujących podczas transmisji danych z wykorzystaniem rzeczywistej sieci telekomunikacyjnej w budynku. Badanie to ma na celu sprawdzenie możliwości wykorzystania telekomunikacji jako alternatywę obecnie wykorzystywanych łączności w inteligentnych budynkach aby docelowo przenieść jak najwięcej elementów do chmury lub rozproszyć system po wszystkich urządzeniach budynkowych. Badanie opóźnień pozwala określić z jakimi opóźnieniami będzie pracował system co jest niezbędne w systemach czasu rzeczywistego.

10

Managing inter-departmental project delivery to enhance customer satisfaction

Cosa Sandiso, Ogbeifun Edoghogho, Pretorius Jan Harm C.

Engineering Management in Production and Services

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2021

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Vol. 13, no. 4

39--56

EN

The National Department of Public Works and Infrastructure (NDPWI), an agency for infrastructure development in South Africa, provides accommodation and other infrastructure to various public service departments. Each department communicates its infrastructure requirements with the NDPWI. However, there are usually time lags between project briefing and the actual delivery of the infrastructure. Therefore, this article aims to explore the causes of delays and offer solutions to enhance customer satisfaction. The case study method of qualitative research was adopted. Data were collected from the NDPWI regional offices in Bloemfontein, Cape Town and Kimberley, and the professional service department at the head office in Pretoria, among purposively selected participants not below the deputy director level. The Delphi technique was used as an instrument for data collection and complemented during a focus group session. The findings revealed that the major factors contributing to delays included poor planning by the project execution team (PET), ineffective project monitoring and overcentralisation of the decision-making process. The findings, conclusions and recommendations of this research provide useful information for organisational restructuring, the training and continuous retraining of project personnel, especially the project managers. These steps hold the potential for ameliorating the negative effects of delay in the execution of construction projects by the NDPWI.

11

Wpływ środowiska realizacji usługi WebRTC na jakość komunikacji

Rzemieniak Michał, Łubkowski Piotr

Elektronika : konstrukcje, technologie, zastosowania

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2021

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Vol. 62, nr 4

14--17

PL

Artykuł dotyczy testowania usługi WebRTC (Web Real Time Communication) w środowisku MiniNet. Przedstawiony został problem wpływu opóźnienia, przepustowości oraz poziomu strat pakietów na jakość komunikacji z wykorzystaniem usługi WebRTC. Przedstawione zostały aplikacje pozwalające na zmianę warunków panujących w sieci oraz aplikacja analizująca audio i wideo pod kątem jakości. Przybliżone zostały trzy scenariusze badań oraz wpływ zmieniających się parametrów w każdym z przypadków na jakość komunikacji.

EN

This article focused on testing the WebRTC (Web Real Time Communication) service in a MiniNet environment. The problem of how latency, bandwidth, and packet loss levels affect the quality of communication using the WebRTC service was shown. Applications that allow changing network conditions and an application that analyses audio and video for quality were presented. Three test scenarios and the impact of changing parameters in each case on the quality of communication are presented.

12

Use of the EVM method for analysis of extending the construction project duration as a result of realization disturbances - case study

Starczyk-Kołbyk Anna, Kruszka Leopold

Archives of Civil Engineering

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2021

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Vol. 67, nr 3

373--393

EN

In pursuing numerous construction projects, investors and contractors regularly face construction delay problems, many of which are likely to have been avoidable. There is found that payment delays and project delays are the two most critical effects of risk factors of construction management. The paper presents the practical application of the Earned Value Management method, which was used to estimate the possible extension of the duration of construction works during which realization disturbances occurred on the example of selected construction investment. The realization disturbances are usually an inseparable element in the implementation of construction works. They are the result of, among others: additional works, changes or design defects, as well as a badly adopted logistics strategy regarding the supply of construction materials. Delays or increasing the total cost of investment is a problem often encountered in the implementation of construction investments, despite advanced construction technologies, including system technologies and proven tools supporting the management of the construction process. The EVM method is used to control investments. It allows you to control delays and acceleration of construction works as well as to estimate their cost and completion date. In the analyzed case it was used to determine the scale of delays arising in construction works and related effects with the specification of the participation of individual participants of the investment process for delays. This paper is a continuation and supplementation of the research presented in the article: “The influence of construction works disturbances on the EVM analysis outcomes - case study” [23].

PL

Realizując liczne projekty budowlane, inwestorzy i wykonawcy regularnie spotykają się z problemami dotyczącymi opóźnienia robót budowlanych, z których wielu prawdopodobnie można byłoby uniknąć. Stwierdzono, że opóźnienia w płatnościach i w realizacji inwestycji to dwa najbardziej krytyczne skutki czynników ryzyka związane z zarządzaniem budową. W artykule przedstawiono praktyczne zastosowanie metody Earned Value Management, która posłużyła do oszacowania możliwego wydłużenia czasu trwania robót budowlanych, podczas których wystąpiły zakłócenia budowlane na przykładzie wybranej inwestycji budowlanej. Nieodłącznym elementem realizacji robót budowlanych są zwykle zakłócenia budowlane. Są wynikiem m.in.: dodatkowych prac, zmian czy wad projektowych, a także źle przyjętej strategii logistycznej w zakresie dostaw materiałów budowlanych. Opóźnienia lub wzrost całkowitego kosztu inwestycji to problem często napotykany przy realizacji inwestycji budowlanych, pomimo zaawansowanych technologii budowlanych, w tym technologii systemowych i sprawdzonych narzędzi wspomagających zarządzanie procesem budowlanym. Do kontroli inwestycji stosowana jest metoda EVM. Pozwala kontrolować opóźnienia i przyspieszenie prac budowlanych oraz oszacować ich koszt i termin zakończenia. W analizowanym przypadku posłużył on do określenia skali opóźnień powstających w robotach budowlanych i związanych z nimi skutków. Niniejszy artykuł jest kontynuacją i uzupełnieniem badań przeprowadzonych na inwestycji budowlanej, przedstawionych w pracy: „Wpływ zakłóceń robót budowlanych na wyniki analizy EVM - studium przypadku” w 2020 r. [23].

13

Przyspieszenia i opóźnienia wzdłużne oraz przyspieszenia poprzeczne w normalnym ruchu drogowym

Reza Adam

Paragraf na Drodze

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2020

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Nr 1

51--67

PL

Przyspieszenia, opóźnienia hamowania i przyspieszenia poprzeczne odgrywają ważną rolę w opiniowaniu wypadków drogowych. Cytowane w artykule wyniki badań pozwalają na określenie przedziałów różnych parametrów dla normalnego, typowego udziału w ruchu drogowym przy wykonywaniu różnych manewrów. Możliwe jest uwzględnienie płci i wieku kierowcy.

EN

The knowledge of acceleration, braking deceleration and transverse acceleration play an important role in road accident expert reporting. The test results quoted in the paper enable the identification of the ranges of various parameters of various driving manoeuvres in ordinary typical participation in road traffic, including the driver’s sex and age.

14

The influence of construction works disturbances on the EVM analysis outcomes - case study

Starczyk-Kołbyk Anna, Kruszka Leopold

Archives of Civil Engineering

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2020

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Vol. 66, nr 1

161--177

EN

The paper presents the problem of building disturbances, which are usually an inseparable element during the implementation of construction projects. They were classified, their causes and sides of the construction process responsible for their creation were identified on the basis of the analyzed construction investment. In addition, using the Earned Value Management method, the scale of delays arising in construction works and the related effects were determined. The important role of close cooperation and good communication between all participants of the construction process was emphasized, which would reduce the phenomenon of building disturbances, but also mitigate the negative effects of delays that have already occurred.

PL

W artykule dokonano szczegółowej analizy procesu inwestycyjnego na etapie wykonawstwa wybranej współczesnej inwestycji kubaturowej finansowanej ze środków budżetowych. Przedstawiono również problem zakłóceń budowlanych, które są z reguły nieodłacznym elementem podczas realizacji przedsięwzięć budowlanych oraz dokonano ich klasyfikacji. Po przeprowadzeniu szczegółowej analizy przedmiotowego procesu budowlanego zidentyfikowano występujące zakłócenia budowlane na badanej inwestycji obejmujące łącznie 1165 dni realizowanego okresu wykonawstwa.

15

Reducing Delay Time at Signal Controlled Junction with the Help of Actuated Control

Černický Ľubomír, Kupčuljaková Jana, Paľo Jozef, Kalašová Alica

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 3

149--157

EN

Nearly every town faces the traffic problem caused by the continuous increase of the traffic volume. Traffic collapses, congestions, accidents and a further negative impact on the environment are gradually becoming a common part of our lives. Junctions are the most critical points of the road network, which usually determine the capacity of the roads. Therefore, proper traffic organization at junctions is a necessity. This paper analyses the actuated control in comparison to the fixed control at a signal-controlled junction. It also includes a case study of one problematic junction in this paper. With the help of microscopic simulation in Aimsun, 2 solutions for this problematic junction were assessed, one of which is fixed control and other is actuated control. Actuated traffic control gives better results than fixed control.

16

Analiza punktualności lotów samolotów pasażerskich w Międzynarodowym Porcie Lotniczym im. Jana Pawła II Kraków-Balice

Bryniarska Zofia, Szczygieł Aneta

Transport Miejski i Regionalny

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2019

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nr 11-12

27--33

PL

Z punktu widzenia pasażerów jedną z ważniejszych cech jakości jest punktualność. W transporcie lotniczym wykonanie operacji przez samoloty i ich obsługa naziemna są znacznie bardziej czasochłonne, a ponadto mocno uzależnione od warunków atmosferycznych. Celem artykułu jest przeprowadzenie analizy punktualności, określenie struktury i wielkości odchyłek punktualności oraz opóźnień i przyspieszeń rejsów pasażerskich wykonywanych w Międzynarodowym Porcie Lotniczym im. Jana Pawła II Kraków-Balice. W artykule przedstawiono podstawowe informacje o Międzynarodowym Porcie Lotniczym w Balicach oraz jego historię i wielkość ruchu lotniczego w ostatnich latach. Omówiono najczęstsze przyczyny opóźnień oraz kody opóźnień opracowane przez Międzynarodowe Zrzeszenie Przewoźników Powietrznych. Zdefiniowano miary i wskaźniki punktualności. Przedstawiono strukturę odchyłek punktualności oraz ocenę statystycznych miar położenia i zmienności odchyłek od punktualności, przyspieszeń i opóźnień lotów dla okresu 12 miesięcy. Analizę punktualności lotów przeprowadzono z podziałem na rejsy krajowe i międzynarodowe w tym okresie oraz dla wybranych dwóch miesięcy roku z podziałem na poszczególne dni. W podsumowaniu przedstawiono wnioski końcowe analizy punktualności samolotów pasażerskich oraz opisano najczęstsze przyczyny opóźnień występujące w Międzynarodowym Porcie Lotniczym im. Jana Pawła II Kraków-Balice wraz ze sposobem ich eliminowania.

EN

From the passengers’ point of view, punctuality is one of the most important quality features. In air transport, the performance of operations by planes and their ground handling are much more timeconsuming, and also heavily dependent on weather conditions. The purpose of the article is to conduct punctuality analysis, determine the structure and size of punctuality deviations as well as delays and accelerations of passenger flights performed at the John Paul II International Airport Krakow-Balice. The article presents not only basic information about the International Airport in Balice but its history and volume of air traffic in recent years as well. The most common causes of delays and delay codes developed by the International Air Transport Association have been discussed. Measures and indicators of punctuality have been defined. The structure of punctuality deviations and the assessment of statistical location measurements and variability of deviations from punctuality, accelerations and delays of flights for a period of 12 months have been presented. Flight punctuality analysis has been conducted in division to national and international flights in this period and for two selected months of the year breakdown by days. The summary presents the final conclusions of the punctuality analysis of passenger aircrafts and describes the most common causes of delays occurring at the John Paul II International Airport Kraków-Balice along with the way to eliminate them.

17

The theory of asymmetrical delay line with the surface acoustic wave for non-electric sensors

Šimko Milan, Chupáč Milan

Przegląd Elektrotechniczny

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2019

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R. 95, nr 1

182--185

EN

In the paper, which deals with the surface acoustic waves, is given the theory of synthesis of the asymmetrical delay line with the interdigital transducer with diluted electrodes. Based on derived theory, an experimentally verified delay line for use in the identification system, filters and resonators based on SAW for further specific applications has been designed.

PL

W niniejszej publikacji dotyczącej powierzchniowych fal akustycznych znajduje się opracowana teoria syntezy nieproporcjonalnej linii opóźniającej z przetwornikiem międzypalcowym z rozcieńczonymi elektrodami. W oparciu o teorię pochodną opracowano i przetestowano eksperymentalnie specyficzne elementy akustoelektroniczne do różnych zastosowań.

18

Third order singularly perturbed delay differential equation of reaction diffusion type with integral boundary condition

Sekar Elango, Tamilselvan Ayyadurai

Journal of Applied Mathematics and Computational Mechanics

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2019

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Vol. 18, nr 2

99--110

EN

A class of third order singularly perturbed delay differential equations of reaction diffusion type with an integral boundary condition is considered. A numerical method based on a finite difference scheme on a Shishkin mesh is presented. The method suggested is of almost first order convergent. An error estimate is derived in the discrete norm. Numerical examples are presented, which validate the theoretical estimates.

19

Practical and asymptotic stabilities for a class of delayed fractional discrete-time linear systems

Ruszewski A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 3

509--515

EN

The practical and asymptotic stabilities of delayed fractional discrete-time linear systems described by the model without a time shift in the difference are addressed. The D-decomposition approach is used for stability analysis. New necessary and sufficient stability conditions are established. The conditions in terms of the location of eigenvalues of the system matrix in the complex plane are given.

20

Faktory opóźnień [w procesie budowy]

Leśniak Agnieszka, Piskorz Grzegorz

Builder

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2019

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R.23, nr 2

26--28

EN

Identification and rank of delay factors in construction projects depending on the project delivery system. The implementation of construction projects depends on many unpredictable factors, which can cause delays in construction works. The article proposes classification of the validity of delay depending on the project delivery system. Two of them were considered: the traditional system (Design – Bid – Build), where the design stage is separated from the construction stage and the design and build (Design & Build), which consists in entrusting design works and carrying out works to one contractor. The order of validity is based on results of research carried out among participants of the construction project.