Parametric types and virtual types have recently been proposed as extensions to Java to support genericity. In this paper we investigate the strengths and weaknesses of each. We suggest a variant of virtual types which has similar expressiveness, but supports safe static type checking. This results in a language in which both parametric types and virtual types are well-integrated, and which is ...

background: the reliability and safety of gas refineries are strongly associated with the reliability of other parts of the system. defect and failure in one part of a system can cause total system breakdown or accident. the failure and damage in these equipment such as transformers and boilers results in not only the equipment damage and human injuries but also productivity reduction. the purp...

An object-oriented language that permits changing the behavior of a class or of a single object is said to support computational reflection. Existing reflective facilities in object-oriented languages are either complex, type unsafe, or have a large performance penalty. We propose a simple, easy-to-understand, and statically typed model that captures much of the functionalities of other reflect...

Safety in air traffic is a multilayered concept and consists of many safety barriers. The practical side of increasing safety is mainly based on analysing the causes of accidents and incidents. This analysis leads to finding gaps in the safety structure and to developing corrective recommendations in order to eliminate them. In this paper we indicate that this practice is insufficient. Most inc...

The development of safety cases has become common practice in many safety critical system domains. Safety cases are costly since they need a significant amount of time and efforts to be produced. Moreover, safety critical systems are expected to operate for a long period of time and constantly subject to changes during both development and operational phases. Hence, safety cases are built as li...

We introduce the blame calculus, which adds the notion of blame from Findler and Felleisen’s contracts to a system similar to Siek and Taha’s gradual types and Flanagan’s hybrid types. We characterise where positive and negative blame can arise by decomposing the usual notion of subtype into positive and negative subtyping, and show that these recombine to yield naive subtyping. Naive typing ha...

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-...

Concurrent C0 is a type-safe, C-like language with session-typed communication that makes writing highly concurrent, message passing programs easier, safer, and more efficient than other languages. Concurrent C0 presents a novel interpretation of a forwarding operation which allows channels to be combined in a well-defined way. We provide Cand Go-based implementations with language based optimi...

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...

We propose a type system for a calculus of contracting processes. Processes may stipulate contracts, and then either behave honestly, by keeping the promises made, or not. Type safety guarantees that a typeable process is honest — that is, the process abides by the contract it has stipulated in all possible contexts, even those containing dishonest adversaries.