?As usual, there are seven papers in this issue besides the review of three recently published books (by Springer and CRC Press). There is one short communication as well.

The first paper relates to the subject of encryption in wireless sensor networks (WSN). Since full encryption to secure the transmitted data is costly and often not practical, the authors suggest a Selective Hybrid Cipher-based mechanism, which integrates AES-based SE and Forward Error Correction codes to achieve both secure and reliable data transmission in WSN.

The second paper, relates to developing dependability models for architectural software systems using the AADL (Architecture Analysis and Design Language) which is a mature industry-standard well suited to address quality attributes. It presents reusable modeling patterns for fault-tolerant applications and demonstrates how these patterns can be used in the context of a subsystem of real-life applications. The authors apply this technique to evaluate two different architectures for French Air Traffic Control System.

The third paper elaborates how to manage risks associated with rail accidents involving legitimate pedestrians crossing, particularly at user-controlled crossings. It considers some issues contributing to the risks including human factors, some modeling approaches as well as some potential ways of addressing the problem. Human behaviour is the key factor and modifying this reliably and consistently is difficult, while designing out the risk can be prohibitively expensive.

The fourth paper deals with the subject of "risk governance", and indicates how one can deal with public risks and so-called complex, ambiguous and uncertain risks in an integrated manner besides providing a conceptual and theoretical basis to design a risk management program, based on risk reduction, resilience and discourse.

In the fifth paper, reliability (or safety) index is computed for a pressure vessel made of titanium alloy. This index is evaluated based on the data collected during manufacturing and operation. Design of Experiment (DOE) and Two Point Adaptive Nonlinear Approximations (TANA) are used to establish the performance functions. AFOSM approach is found to give better results.

The sixth paper provides a time-dependent probabilistic analysis of a structure. It is shown that the deterministic time dependent analysis can be done conveniently using lognormal probability model at every time instant. There is a good agreement with Monte Carlo simulation technique. The present study demonstrates that structural response in terms of deflection over a given life time is directly related to design criteria used by structural engineer.

The last paper relates to the design of Quantum Cellular Automata (QCA), which is emerging as a very interesting computational nanotechnology paradigm. The aim of the paper is to create interest in this area of research.

It is hoped that the readers of IJPE will find the coverage of this issue useful for their research and professional interest.

In wireless sensor networks (WSN), data packets being sent over wireless environments could get corrupted or compromised due to channel noises or malicious attacks. Using traditional full encryption to secure the transmitted data is costly and even not practical for WSN due to the inherent resource-constrained nature of sensor nodes. Selective encryption (SE) that encrypts part of the data can greatly reduce the computational overhead for huge volumes of data in low-power networks. Encrypted data is more sensitive to transmission errors; therefore, additional error correction capability is required to efficiently recover the lost/erroneous encrypted information. In this paper, we propose a new Selective Hybrid Cipher-based mechanism, which integrates AES-based SE and Forward Error Correction codes to achieve both secure and reliable data transmission in WSN. Performance of the proposed mechanism is evaluated using simulations, and is compared with that of the traditional SE-based and full encryption-based mechanisms.
Received on April 29, 2010, revised on April 5, 2011
References: 23

In traditional development processes, each type of analysis is generally based on a dedicated model, which requires substantial amount of training to be used effectively. Performing dependability evaluation along with other analyses at architectural level allows both making architectural tradeoffs and predicting the effects of architectural decisions on the dependability of an application. This paper is related to the building of dependability models for architectural software systems using the AADL (Architecture Analysis and Design Language). It presents reusable modeling patterns for fault-tolerant applications and shows how the presented patterns can be used in the context of a subsystem of a real-life application.
Received on March 10, 2010 and revised on March 31, 2011
References: 26

This paper explores some aspects of communication with rail stakeholders in order to manage risks associated with rail accidents involving pedestrians legitimately crossing tracks at user-controlled crossings. It considers some issues contributing to the risks including human factors, some modelling approaches as well as some potential ways of addressing the problem. Ultimately, a key factor is human behaviour. Modifying this reliably and consistently is difficult, while designing out the risk is likely to be prohibitively expensive.
Received on October 08, 2009, revised on August 31, 2010
References: 44

The notion “risk governance” refers to an integrated concept on how to deal with public risks in general, and so-called complex, ambiguous and uncertain risks in particular. These ideas have been informed by interdisciplinary research drawing from sociological and psychological research on risk, Science & Technology Studies (STS) and research by policy scientists and legal scholars. The notion of risk governance pertains to the many ways in which many actors, individuals and institutions, public and private, deal with risks. It includes formal institutions and regimes and informal arrangements. It thus pertains to the complex whole of what traditionally has been called -and treated as separate activities- “risk assessment”, “risk management” and “risk communication”. After a short summary of the roots of risk governance, key concepts, such as simple, uncertain, complex and ambiguous risks, will be discussed. The main emphasis will be on each of the five phases of risk governance: pre-assessment, appraisal, risk characterization/evaluation; risk management and risk communication. The paper will first provide some theoretical and conceptual thoughts on how to design risk management programs based on risk reduction, resilience and discourse.
Received on August 08, 2009 revised on October 16, 2009 and finally on April 7, 2011
References: 54

Structural safety is one of the most important factors of any aerospace product. Until recently, a design was considered to be robust if all the variables that affected its life has been accounted for and brought under control. The meaning of robustness is changing. Designers and engineers have traditionally handled variability with safety factors. In this paper a pressure vessel made of titanium alloy is considered for structural reliability (safety index) study. The safety index is evaluated based on the data collected during manufacturing and operation. Various methods used for safety evaluation have been discussed. Design Of Experiment (DOE) and Two Point Adaptive Nonlinear Approximations (TANA) are used to establish the performance functions.? These relations are very useful when exact parametrical relations are not available. Moreover, these linear and nonlinear functional relations are useful in optimization problem formulation. The safety evaluation is also carried out with strength-stress interference method. The linear and nonlinear approximation models are validated and found in good agreement with experimental results.
Received on May 27, 2010, revised on March 28, 2011
References: 11

In this paper an attempt is made to formulate time dependent reliability analysis of flanged reinforced concrete beam in limit state of deflection. Normal range of flanged beams designed for limit state of safety as per the guidelines of IS 456:2000 for typical range of dead load and live loads are considered for evaluating time dependent failure probabilities. The algorithm takes into account the concrete maturation, tension stiffening, time dependent shrinkage and creep effect, variability related to material properties, dimensions and loads. Deterministic deflection model given in IS code is used to get deflection samples by Monte Carlo simulation technique. Further it is shown that? time dependent probabilistic analysis of the structure can be done conveniently from the deterministic time dependent analysis with lognormal probability model at every time instant. There is a good agreement with Monte Carlo simulation technique. The present study demonstrates that structural response in terms of deflection over a given life time is directly related to design criteria used by structural engineer.
Received on February 12, 2010, revised on October 18, 2010
References: 13

Quantum Cellular Automata (QCA) present one of the many emerging computational nanotechnology paradigms.? It uses the arrangements of individual electrons, instead of currents and voltages, to encode binary information.? Note a QCA cell consists of four quantum dots located at the corners of a square. This tutorial paper provides an introductory material on the design and testing of combinational logic using a QCA based majority gate.? The objective is to create an interest among readers of IJPE in the area of QCA and testing of combinational circuits.
Received on November 21, 2010, revised on April 12, 2011
References: 21

In this article we extend quality control research into nominal and ordinal data from simple monitors of location to those of variability. Given ordinal data more traditional process control relies on demerit systems that explicitly monitor central location but not the distribution spread. It is quantified here in terms borrowed from ecology. An established index of diversity and its standard error are the basis for a new quality control chart that we have also assessed with respect to error rates.
Received on November 19 2010; revised on March 15 and April 6, 2011
References: 09