The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Packet collision and packet delay are considered to be critical for safety applications in vehicular networks. This paper designs a new analytical model to evaluate the performance of channel switching for IEEE 802.11p/WAVE in vehicular networks. Under this model, it explicitly expresses the WAVE channel switching, and constructs contention window size and number of vehicles as packet collision probability...
To move mixed criticality research into industrial practice requires models whose run-time behaviour is acceptable to systems engineers. Certain aspects of current models, such as abandoning lower criticality tasks when certain situations arise, do not give the robustness required in application domains such as the automotive and aerospace industries. In this paper a new bailout protocol is developed...
In vehicular networks, multi-channel operation standard IEEE 1609.4 is designed for vehicular communications across multiple channels. It has been revealed that such multi-channel operations may result in high contention in vehicular communications. However, existing analytical models are unable to capture the dynamic characteristic during channel switching. We develop a novel Markov model that takes...
Modern automotive systems consist of hundreds of functionalities implemented in software. Moreover, these functionalities are constantly evolving with increasing demand for automation, industry competition and changing sensor and actuator capabilities. Correspondingly, it is important to adapt the engineering and software development processes for such systems to consider fast management of this evolution...
In this paper, we propose a new approach for modeling and evaluating reliability of complex public safety network. Based on Bayesian network structure, we develop a general construction methodology for network representation and design. Using probability propagation techniques, the reliability of the system can be obtained in a straightforward manner. To evaluate our model, the proposed method is...
OCRA provides a language and tool support to model and analyze acomponent-based architecture enriched with contracts. Assumptions andguarantees of components are specified in different variants oflinear-time temporal logics, supporting variables with infinitedomains and continuous dynamics. The tool provides different analysistechniques including contracts refinement checking, contract-basedcompositional...
Modern buildings are often expected to satisfy minimum safety requirements to define upper bounds for safety metrics, such as evacuation time. The building design must therefore consider prediction of these metrics for a set of representative evacuation scenarios. These scenarios can be rather complex, and often can be investigated only using building evacuation simulators. However, these simulators...
Research on the waterway traffic flow modelling has been widely used in the formulation of waterway transportation regulations, navigation risk assessment, vessel traffic monitoring and organization. The fluency of one-way waterway transportation is proposed in this paper. By using the model, a simulation system is constructed on the basis of First Come First Served (FCFS) model. Monte Carlo simulations...
Some ship crew reported that there is deficiency of manning of engine department in The Three Gorges Reservoir Area which results in serious safety risks. To ensure the navigation safety and legal right of crew, it is of great necessity to re-evaluate the minimum safe manning standard of engine department in such area. By applying on board function model, the functions of engine department, which...
Safety analysis is increasingly important for a wide class of systems. In the automotive field, the recent ISO26262 standard foresees safety analysis to be performed at system, hardware, and software levels. Failure Modes and Effects Analysis (FMEA) is an important step in any safety analysis process, and its application at hardware and system levels has been extensively addressed in the literature...
Safety-Critical systems, as used in the automotive, avionics, or aerospace domains, are becoming increasingly software-reliant to the extent that the system cannot function without the software. On one hand the software system provides an integrated set of functionality to operate the system and manage failure and unsafe conditions. Current best safety engineering practices, such as DO178B/C or SAE...
An analytical model is proposed to improve the performance of emergency message broadcast in VANET that supports both highly dense and sparse traffic conditions. In this paper we propose (i)IEEE 802.11p WAVE mode, that reduces the connection setup overhead (ii)priority schemes for three levels of safety service (iii)D-FPAV congestion control algorithm that supports both traffic & non-traffic situations...
The simulation test based on damage equivalent principle was carried out in consideration of ammunition safety under highway transportation vibration, taking a certain type of cartridge as the research object. The test results indicated that the excited vibration has no clear effects on the cartridge performance, the indexes can remain consistent before and after test, and the package also meets the...
To ensure the normal production, it is necessary to have a safety inventory as a buffer. Safety inventory is mainly affected by the following factors: the expected customer service, the mean value and standard deviation of the lead time, the mean value and standard deviation of demand. We build a system dynamics model to analyze impacts of the several factors above on the safety inventory. We design...
In order to more effectively assess the safety risk of a wind farm project, the evaluation indicators in the life cycle of a project can be divided into quality index, cost index, time index, security index, and sustainable development index. By combining the qualitative with quantitative, the model of principal component analysis (PCA) of the life cycle indicators was established, which can reflect...
Certification is a major prerequisite for most safety-critical systems before they can be put into operation. During certification, system suppliers often have to present a coherent body of evidence demonstrating that the developed systems are safe for operation. Regardless of the certification approach taken (process-based or product-based), collection of proper evidence at the proper stage ofdevelopment...
Firstly, this article introduce foreign theoretical research of risk management in the subway tunnel project from four aspects that evaluation theory, management model, accident statistics, risk analysis. Secondly, the paper analyze foreign practice research of risk management in the subway tunnel project from four aspects that computer simulation, information platform, standards, government regulations...
In today's train operations the driver may no longer be the primary guardian of the safety of the train, that function being taken over by various forms of automatic train protection (ATP) systems. What is left for the driver is still an important safety supporting function which is their capacity to review the set of train control actions that they intend to apply, and match those with the current...
This paper presents a formal approach to model the traffic operational processes on a Maglev train example based on Stochastic Petri nets. The Maglev train is modeled with respect to process, function and dependability. Process model describes the normal running status and abnormal protected status of the Maglev train from departure to stopping and function model shows the working principle of propulsion...
The construction industry has been facing a paradigm shift to (i) increase; productivity, efficiency, infrastructure value, quality and sustainability, (ii) reduce; lifecycle costs, lead times and duplications, via effective collaboration and communication of stakeholders in construction projects. Digital construction is a political initiative to address low productivity in the sector. This seeks...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.