This paper discusses the issue of order crossover and its effects in order point, lot size (s, Q) inventory systems. Orders are likely to cross when their lead times are stochastic. Two inventory systems are considered to examine the consequences of order crossover. The first inventory system considers a fast moving item having deterministic demand and stochastic lead time. It is assumed lead t...

Fault tree technique has been used in industry for safety analysis of safety critical systems for decades. They can be used for analysing the safety of both software and hardware. However, there are a lot of problems in ensuring the internal consistency and validity of fault trees constructed due to the absence of appropriate approach of using fault tree technique. This paper describes a model-...

In this paper two system safety models are built based on some practical situations. The system state can be distinguished into three states: working, fail-safe and fail-dangerous.The probabilities that the system are in working state, fail-safe state and fail-dangerous state, respectively, are derived. Also the mean times for the system working, fail-safe and fail-dangerous, are given. Finally...

This paper deals with an inverse problem for identifying an unknown source which depends only on one variable in two-dimensional Poisson equation, with the aid of an extra measurement at an internal point. Since this problem is illposed, we obtain the regularization solution by the modified regularization method. Furthermore, we obtain the Hölder-type error estimate between the regularization s...

Probabilistic model; Inventory; Varying order cost; Holding cost; Lead-time demand; Uniform distribution; Safety stock Abstract This paper discusses the probabilistic backorders inventory system when the order cost unit is a function of the order quantity. Our objective is to minimize the expected annual total cost under a restriction on the expected annual holding cost when the lead time deman...

Component fault trees that contain safety basic events as well as security basic events cannot be analyzed like normal CFTs. Safety basic events are rated with probabilities in an interval [0,1], for security basic events simpler scales such as {low, medium, high} make more sense. In this paper an approach is described how to handle a quantitative safety analysis with different rating schemes f...

Safety cases embody arguments that demonstrate how safety properties of a system are upheld. Such cases implicitly document the barriers that must exist between hazards and vulnerable components of a system. For safety certification, it is the analysis of these barriers that provide confidence in the safety of the system. The explicit representation of hazard barriers can provide additional ins...

every year, many accidents leading to physical injuries in kindergartens, indicates that a very large percentage of them are related to the safety concerns and lack of hygiene in these places. families, due to their busy life style and working hours and also children needs of preschool education, are searching to find most suitable kindergartens for their children. selecting a kindergarten with...

Several requirements analysis techniques widely used in safety-critical systems are being adapted to support the analysis of secure systems. Perhaps the most relevant system safety technique for Intrusion Detection Systems is hazard analysis. Hazard analysis identi es and analyzes hazards (states that can lead to an accident) in terms of their severity of e ects and likelihood of occurrence. As...

construction of asphaltic core dams is a relatively novel method especially in iran. iran is located in a region with high seismicity risk. therefore, many researchers have focused on the behavior of such types of dams under earthquake loading. in this research, the behavior of asphaltic core rockfill dams (acrd) has been studied under earthquake loading using nonlinear dynamic analysis method ...