A New Model of Safety Management System for Railway Operation

Safety management systems (SMSs) were introduced to the rail industry as a proactive way to manage safety and prevent accidents. However, accidents still occur where the SMS has been implemented but ineffective. It is, therefore, of great importance to have a reality check of what the role and functions of an SMS are in order to understand why the SMS does not prevent organisational accidents and to identify the weakness of SMS as underlying causes in accidents. This paper is a summary of the report based on previous research (Pan, 2014). It presents a systemic review of SMS elements based on analysis of accident reports and proposes an innovative SMS model in order to discover potential improvements for SMS implementation. The review based on selected accident reports focused on analysing the individual SMS elements involved in the accidents and identified the most critical elements in accidents are safety-related information management, risk assessment and competence management. The main findings from the research lie in the failure patterns of SMS elements in accidents, organisational features of the rail accidents, inadequate standards for SMS design, and industrial emphasis in implementation. We gave our recommendations on SMS implementations based on this review. And future research can be processed in the areas of improvement of the SMS model, detailed analysis of SMS involvement in the accidents, and the actual value of the SMS

Agile security for web applications

Web-based applications (or more concisely, Web applications) are a kind of information system with a particular architecture. They have progressively evolved from Internet browser-based, read-only information repositories to Web-based distributed systems. Today, increasing numbers of businesses rely on their Web applications. At the same time, Web applications are facing many security challenges and, as a result, are exposing businesses to many risks. This thesis proposes a novel approach to building secure Web applications using agile software development methods

Analysing Railway Safety with Systems Thinking

Railway system is a socio-technical system because the operation of such system also heavily relies on the management of human activities and operating procedures in the organisation, as well as the execution of technical subsystems. Safety of these systems therefore is more than just about engineering their technical subsystems. The latest approach from systems engineering considers that an accident is due to inadequate controlled interactions in the system and is usually a dynamic event chain started from the activation of a hazard and culminated in a complex process of sequential and concurrent events until the system is eventually out of control. Meanwhile the analysis of these systems’s safety becomes much harder when simply applying the traditional techniques of safety assessment. It is because, first of all, a social-technical system consists of a lot of complex and non-linear interactions, traditional techniques show their limits when analysing complex systems. And secondly, the safety of a social-technical system requires a system perspective, which should take all the behaviours (desired and undesired but predicted) of a system as a whole in the context of its environment. To capture the information needed, the models for these analyses (i.e., fault tree and FMEA table) will become too complex to have a systemic view of each individual causal factor. In this paper, we proposed an approach based on system thinking and system dynamics to analyse the safety of a social-technical system. The case study of a tram accident is simple enough for the purpose of demonstrating its feasibility and benefits. The comparison with fault tree analysis was conducted, but it was not for the evaluation of our approach. The real evaluation comes from the extensive applications in real world

Failure Propagation Modeling and Analysis Via System Interfaces

Safety-critical systems must be shown to be acceptably safe to deploy and use in their operational environment. One of the key concerns of developing safety-critical systems is to understand the system behaves in the presence of failures, regardless of whether that failure is triggered by the external envi- ronment, or caused by internal errors. Safety assessment at the early stages of system development involves analysis of potential failures and their conse- quences. Increasingly, for complex systems, model-based safety assessment is becoming more widely used. In this paper we propose an approach for safety analysis based on system interface models. By extending interaction models on the system interface level with failure modes as well as relevant portions of the physical system to be controlled, automated support could be provided for much of the failure analysis. We focus on fault modeling and on how to compute minimal cut sets. Particularly, we explore state space reconstruction strategy and bounded searching technique to reduce the number of states that need to be analyzed, which remarkably improves the efficiency of cut sets searching algorithm

A Non-Intrusive Pressure Sensor by Detecting Multiple Longitudinal Waves

Pressure vessels are widely used in industrial fields, and some of them are safety-critical components in the system - for example, those which contain flammable or explosive material. Therefore, the pressure of these vessels becomes one of the critical measurements for operational management. In the paper, we introduce a new approach to the design of non-intrusive pressure sensors, based on ultrasonic waves. The model of this sensor is built based upon the travel-time change of the critically refracted longitudinal wave (LCR wave) and the reflected longitudinal waves with the pressure. To evaluate the model, experiments are carried out to compare the proposed model with other existing models. The results show that the proposed model can improve the accuracy compared to models based on a single wave

Expression pattern divergence of duplicated genes in rice

<p>Abstract</p> <p>Background</p> <p>Genome-wide duplication is ubiquitous during diversification of the angiosperms, and gene duplication is one of the most important mechanisms for evolutionary novelties. As an indicator of functional evolution, the divergence of expression patterns following duplication events has drawn great attention in recent years. Using large-scale whole-genome microarray data, we systematically analyzed expression divergence patterns of rice genes from block, tandem and dispersed duplications.</p> <p>Results</p> <p>We found a significant difference in expression divergence patterns for the three types of duplicated gene pairs. Expression correlation is significantly higher for gene pairs from block and tandem duplications than those from dispersed duplications. Furthermore, a significant correlation was observed between the expression divergence and the synonymous substitution rate which is an approximate proxy of divergence time. Thus, both duplication types and divergence time influence the difference in expression divergence. Using a linear model, we investigated the influence of these two variables and found that the difference in expression divergence between block and dispersed duplicates is attributed largely to their different divergence time. In addition, the difference in expression divergence between tandem and the other two types of duplicates is attributed to both divergence time and duplication type.</p> <p>Conclusion</p> <p>Consistent with previous studies on <it>Arabidopsis</it>, our results revealed a significant difference in expression divergence between the types of duplicated genes and a significant correlation between expression divergence and synonymous substitution rate. We found that the attribution of duplication mode to the expression divergence implies a different evolutionary course of duplicated genes.</p

Pressure measurement based on multi-waves fusion algorithm

Measuring the pressure of a pressure vessel accurately is one of fundamental requirements of the operation of many complex engineering systems. Ultrasonic technique has been proposed to be a good alteration of non-intrusive measurement. Based on the study of acoustoelastic effect and thin-shell theory, it has been identified that the travel-time changes of the critically refracted longitudinal wave (LCR wave) and other reflected longitudinal waves are all proportional to the inner pressure. Considering the information redundancy in these waves, we proposed an approach for pressure measurement by using the information fusion algorithm on multiple reflected longitudinal waves. In the paper, we discussed the fusion algorithm in details and proposed a pressure measurement model, which represents an accurate relationship between the pressure and the travel-time changes of multiple waves. Through the experiment, the analysis of data collected from experiment system showed that the pressure measurement based on the multi-wave model is notably more accurate than the one based on the single-wave model (the average relative error (ARE) can be less than 7.24% and the root-mean-square error (RMSE) can be lower than 0.3MPa)

ABrowse - a customizable next-generation genome browser framework

<p>Abstract</p> <p>Background</p> <p>With the rapid growth of genome sequencing projects, genome browser is becoming indispensable, not only as a visualization system but also as an interactive platform to support open data access and collaborative work. Thus a customizable genome browser framework with rich functions and flexible configuration is needed to facilitate various genome research projects.</p> <p>Results</p> <p>Based on next-generation web technologies, we have developed a general-purpose genome browser framework ABrowse which provides interactive browsing experience, open data access and collaborative work support. By supporting Google-map-like smooth navigation, ABrowse offers end users highly interactive browsing experience. To facilitate further data analysis, multiple data access approaches are supported for external platforms to retrieve data from ABrowse. To promote collaborative work, an online user-space is provided for end users to create, store and share comments, annotations and landmarks. For data providers, ABrowse is highly customizable and configurable. The framework provides a set of utilities to import annotation data conveniently. To build ABrowse on existing annotation databases, data providers could specify SQL statements according to database schema. And customized pages for detailed information display of annotation entries could be easily plugged in. For developers, new drawing strategies could be integrated into ABrowse for new types of annotation data. In addition, standard web service is provided for data retrieval remotely, providing underlying machine-oriented programming interface for open data access.</p> <p>Conclusions</p> <p>ABrowse framework is valuable for end users, data providers and developers by providing rich user functions and flexible customization approaches. The source code is published under GNU Lesser General Public License v3.0 and is accessible at <url>http://www.abrowse.org/</url>. To demonstrate all the features of ABrowse, a live demo for <it>Arabidopsis thaliana </it>genome has been built at <url>http://arabidopsis.cbi.edu.cn/</url>.</p

A Modeling and Experiment Framework for the Emergency Management in AHC Transmission

Emergency management is crucial to finding effective ways to minimize or even eliminate the damage of emergent events, but there still exists no quantified method to study the events by computation. Statistical algorithms, such as susceptible-infected-recovered (SIR) models on epidemic transmission, ignore many details, thus always influencing the spread of emergent events. In this paper, we first propose an agent-based modeling and experiment framework to model the real world with the emergent events. The model of the real world is called artificial society, which is composed of agent model, agent activity model, and environment model, and it employs finite state automata (FSA) as its modeling paradigm. An artificial campus, on which a series of experiments are done to analyze the key factors of the acute hemorrhagic conjunctivitis (AHC) transmission, is then constructed to illustrate how our method works on the emergency management. Intervention measures and optional configurations (such as the isolation period) of them for the emergency management are also given through the evaluations in these experiments