reliability

Improved calculation and strength of thermowells during operation

Accurate evaluation of possible safe operation of thermowells essentially depends on the accuracy of the maximum stresses in them during operation. These stresses are generally determined from simple engineering formulas for bulk of canonical shape, mostly cylindrical shells or beams for the relevant boundary conditions. Thus the general solution is obtained step by step. First the tangential stresses are obtained from relations for cylinder subjected to external pressure.

Responsibility for environmental, including st.246 – illegal cutting of forests

Destruction of forests in Ukraine is one of the current challenges that concern not only environmental, but also ordinary citizens. Uncontrolled deforestation, especially in winter, reaches a critical level. Every day, thousands of illegally felled trees. Experts note that the most objective of reducing the area of the Ukrainian forests and felling oldest arrays show pictures from space.

THE BASIC STOCHASTIC PARAMETERS IN ASSESSING OF THE RELIABILITY OF REINFORCED CONCRETE BEAMS STRENGTHENED BY ADDITIONAL REINFORCEMENT BARS

Today there are many scientific and technical knowledge that make construction a reliable, fast and economical. To provides a safe and durable (the fundamental components of reliability) of builnings and structures are developed the methods of reliability theory. Improving the methods of calculation is enables researchers and designers to create effective structures with a preset (expedient) level of reliability, which directly affects to an amount of required materials and, appropriately, a cost of future building objects in general.

Software Failure Intensity Modelling and Identification the Margins of the Complexity Index

The behaviour of failure intensity function for software reliability model with complexity index depending on the model parameters has been simulated. It allows identifying the margins of the complexity index and explaining the defect revealing function behaviour depending on software complexity.

Extending the features of software for reliability analysis of fault-tolerant systems

The developed software ASNA-2, which is an improved version of the software ASNA-1, is based on the technology of automated estimation of reliability indexes of fault-tolerant systems. This software is designed for automated evaluation of the reliability indexes of fault-tolerant hardware – software systems. This paper describes a software ASNA-2 with the peculiarities of procedures of  reliability analysis of fault-tolerant systems.

Analytical reliability model of a redundant repairable system with limited number of restorations

Modern complex mission-critical systems are built as fault-tolerant systems, i.e. having the ability to function while some of their separate elements have a fault. The complexity of such fault-tolerant systems makes their reliability models quite big and complex. Therefore, such requirements for building models, as the high level of credibility and the appropriate level of formalization, are imposed on these models, which allows to implement the automation to their creating and analysis of reliability and, therefore, using modern computer tools.

The model of radioelectronic system reliability control effectiveness

The article is concerned with the analytical evaluation data of the effectiveness of the electrodynamic system reliability control. The basis of the consideration is a study of information efficiency of interaction between a radioelectronic system and that of electronic control. The analytical expressions obtained allow the optimal ratio between the reliable and most effective operating mode of control systems to be chosen. The problem of optimal control of reliability of functioning the radioelectronic control system is stated.

Estimation the reliability of hardware/software systems by using models of their behavior

Hardware/software systems provide flexible implementation of microprocessors, microcontrollers and various peripheral devices and supply the ability to perform almost any functional algorithm that can be simply modified or replaced. For reliability estimation of hardware/software systems we must take into account not only the loss of efficiency, which was caused by the hardware failures, but the abnormal functioning, that was caused by software failures. All these features of hardware/software systems must be considered in their models for reliability indexes estimation.

85 років становлення ідей надійності в будівництві

A brief analytical overview of the structural reliability theory. Analysis of the development of the theory in the framework of adaptation in Ukraine Eurocode package of normative documents and preparation of national annexes carried out.