210,376 research outputs found
Expert System for Diagnosis of Motor Failures in Electronic Injection Vehicles
Today, cars are an indispensable element in the society, as well as the vehicle diagnosis of minor and serious mechanical failures. This process is carried out through two methods: (i) manually, inspecting possible common causes; and (ii) automatically, using a failure identification scanner. In both cases the assistance of a car expert is required. However, how could a common user briefly diagnose vehicle failures? The objective of this project has been to build an expert system module for vehicular diagnosis to help the common user, identifying automotive failures and the severity of the vehicle damage. It also helps to prevent major damages and possible accidents, as well as to achieve a technical and effective communication when the situation is being explained to the mechanical assistance which can be even by telephone. The module design was composed by four phases: (i) do background research about failure diagnosis, (ii) production rules; (iii) inference engine; and (iv) user interface. The results show that the expert system module is 71,43% effective, so that it helps the common user to identify electronic engine failures without the assistance of a professional in the area
Effects of the manufacturing process on the reliability of the multilayer structure in MetalMUMPs actuators: Residual stresses and variation of design parameters
© 2017 by the authors. Potential problems induced by the multilayered manufacturing process pose a serious threat to the long-term reliability of MEMSCAPŸ actuators under in-service thermal cycling. Damage would initiate and propagate in different material layers because of a large mismatch of their thermal expansions. In this research, residual stresses and variations of design parameters induced by metal multi-user micro electromechanical system processes (MetalMUMPs) were examined to evaluate their effects on the thermal fatigue lifetime of the multilayer structure and, thus, to improve MEMSCAPŸ design. Since testing in such micro internal structure is difficult to conduct and traditional testing schemes are destructive, a numerical subdomain method based on a finite element technique was employed. Thermomechanical deformation from metal to insulator layers under in-service temperature cycling (obtained from the multiphysics model of the entire actuator, which was validated by experimental and specified analytical solutions) was accurately estimated to define failures with a significant efficiency and feasibility. Simulation results showed that critical failure modes included interface delamination, plastic deformation, micro cracking, and thermal fatigue, similarly to what was concluded in the MEMSCAPŸ technical report
Heart Failure Monitoring System Based on Wearable and Information Technologies
In Europe, Cardiovascular Diseases (CVD) are the leading source of death, causing 45% of all deceases. Besides, Heart Failure, the paradigm of CVD, mainly affects people older than 65. In the current aging society, the European MyHeart Project was created, whose mission is to empower citizens to fight CVD by leading a preventive lifestyle and being able to be diagnosed at an early stage. This paper presents the development of a Heart Failure Management System, based on daily monitoring of Vital Body Signals, with wearable and mobile technologies, for the continuous assessment of this chronic disease. The System makes use of the latest technologies for monitoring heart condition, both with wearable garments (e.g. for measuring ECG and Respiration); and portable devices (such as Weight Scale and Blood Pressure Cuff) both with Bluetooth capabilitie
Recognizing risk-of-failure in communication design projects
The pace of commercial graphic design practice presents very few opportunities to conduct user research after a projectâs launch. This makes the design teamâs ability to anticipate and address risks during the design development phase even more important, recognized in the astute observation from Tim Brown, CEO of leading international design group IDEO, that sometimes you must âfail early to succeed early.â
This paper presents the methods and strategies used by the Centre for Design Researchâs (CfDR) creative team to mitigate risk during three communication design case-study projects. Elements of failure are identified in each of the three cases and presented, with discussion of where and why they occurred, and the possible approaches for reducing the risk of such problems re-occurring. To provide structure to the discussion, the paper frames each contributory issue as either a usability, communication or technical failing.
The analysis demonstrates that the factors contributing to design process failures are often complex and multi-layered. To avoid a poor design project outcome, it is evident that consistent risk monitoring is present in all stages of a design project, but might be improved by better understanding how issues change their degree of importance and potential negative impact during the course of the
project. Developing a mechanism to enable teams to objectively identify and manage these fluctuating project risks, will contribute to a more coherent and effective strategy for recognizing and managing future design projects
Situating the transient user: overcoming challenges in the design of e-government systems
e-Government systems present new challenges for user involvement in the design process. Existing user-centred and participatory design methodologies were mainly developed for situations where a user is in the workplace. In e-government applications the user population is heterogeneous and numerous; the increasing ubiquity of e-government systems also questions the concept of âthe interfaceâ. This paper presents the results of a study of discourses of e-government users in two cases studies of interaction with new information systems in transport, which illuminate usability problems arising from a failure to prioritise usersâ needs at all stages. An approach is proposed which accounts for the values as well as the goals of users, appropriating stakeholder analysis and ideas from Soft Systems Methodology while recognising that the routine actions of users in the real world are situated and contingent
ATM automation: guidance on human technology integration
© Civil Aviation Authority 2016Human interaction with technology and automation is a key area of interest to industry and safety regulators alike. In February 2014, a joint CAA/industry workshop considered perspectives on present and future implementation of advanced automated systems. The conclusion was that whilst no additional regulation was necessary, guidance material for industry and regulators was required. Development of this guidance document was completed in 2015 by a working group consisting of CAA, UK industry, academia and industry associations (see Appendix B). This enabled a collaborative approach to be taken, and for regulatory, industry, and workforce perspectives to be collectively considered and addressed. The processes used in developing this guidance included: review of the themes identified from the February 2014 CAA/industry workshop1; review of academic papers, textbooks on automation, incidents and accidents involving automation; identification of key safety issues associated with automated systems; analysis of current and emerging ATM regulatory requirements and guidance material; presentation of emerging findings for critical review at UK and European aviation safety conferences. In December 2015, a workshop of senior management from project partner organisations reviewed the findings and proposals. EASA were briefed on the project before its commencement, and Eurocontrol contributed through membership of the Working Group.Final Published versio
CRAFT: A library for easier application-level Checkpoint/Restart and Automatic Fault Tolerance
In order to efficiently use the future generations of supercomputers, fault
tolerance and power consumption are two of the prime challenges anticipated by
the High Performance Computing (HPC) community. Checkpoint/Restart (CR) has
been and still is the most widely used technique to deal with hard failures.
Application-level CR is the most effective CR technique in terms of overhead
efficiency but it takes a lot of implementation effort. This work presents the
implementation of our C++ based library CRAFT (Checkpoint-Restart and Automatic
Fault Tolerance), which serves two purposes. First, it provides an extendable
library that significantly eases the implementation of application-level
checkpointing. The most basic and frequently used checkpoint data types are
already part of CRAFT and can be directly used out of the box. The library can
be easily extended to add more data types. As means of overhead reduction, the
library offers a build-in asynchronous checkpointing mechanism and also
supports the Scalable Checkpoint/Restart (SCR) library for node level
checkpointing. Second, CRAFT provides an easier interface for User-Level
Failure Mitigation (ULFM) based dynamic process recovery, which significantly
reduces the complexity and effort of failure detection and communication
recovery mechanism. By utilizing both functionalities together, applications
can write application-level checkpoints and recover dynamically from process
failures with very limited programming effort. This work presents the design
and use of our library in detail. The associated overheads are thoroughly
analyzed using several benchmarks
Designing Interfaces to Support Collaboration in Information Retrieval
Information retrieval systems should acknowledge the existence of collaboration in the search process. Collaboration can help users to be more effective in both learning systems and in using them. We consider some issues of viewing interfaces to information retrieval systems as collaborative notations and how to build systems that more actively support collaboration. We describe a system that embodies just one kind of explicit support; a graphical representation of the search process that can be manipulated and discussed by the users. By acknowledging the importance of other people in the search process, we can develop systems that not only improve help-giving by people but which can lead to a more robust search activity, more able to cope with, and indeed exploit, the failures of any intelligent agents used
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An Approach to Using Non Safety-Assured Programmable Components in Modest Integrity Systems
Programmable components (like personal computers or smart devices) can offer considerable benefits in terms of usability and functionality in a safety-related system. However there is a problem in justifying the use of programmable components if the components have not been safety justified to an appropriate integrity (e.g. to SIL 1 of IEC 61508). This paper outlines an approach (called LowSIL) developed in the UK CINIF nuclear industry research programme to justify the use of non safety-assured programmable components in modest integrity systems. This is a seven step approach that can be applied to new systems from an early design stage, or retrospectively to existing systems. The stages comprise: system characterisation, component suitability assessment, failure analysis, failure mitigation, identification of additional defences, identification of safety evidence requirements, and collation and evaluation of evidence. In the case of personal computers, there is supporting guidance on usage constraints, claim limits on reliability, and advice on âlocking downâ the component to maximise reliability. The approach is demonstrated for an example system. The approach has been applied successfully to a range of safety-related systems used in the nuclear industry
Making intelligent systems team players: Overview for designers
This report is a guide and companion to the NASA Technical Memorandum 104738, 'Making Intelligent Systems Team Players,' Volumes 1 and 2. The first two volumes of this Technical Memorandum provide comprehensive guidance to designers of intelligent systems for real-time fault management of space systems, with the objective of achieving more effective human interaction. This report provides an analysis of the material discussed in the Technical Memorandum. It clarifies what it means for an intelligent system to be a team player, and how such systems are designed. It identifies significant intelligent system design problems and their impacts on reliability and usability. Where common design practice is not effective in solving these problems, we make recommendations for these situations. In this report, we summarize the main points in the Technical Memorandum and identify where to look for further information
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