Improvement of industrial efficiency by knowledge management in maintenance engineering

Directory of Open Access Journals (Sweden)

Carlos Alberto Mariotoni

2015-09-01

Full Text Available This article shows research and studies dealing with the management of knowledge in industrial maintenance engineering, developed in the field of applied research in real industrial companies of Europe, which are the consequences of  having knowledge on islands, as well as measures improvements when there is an adequate knowledge management. The peculiarities which are given in the maintenance of the company departments, knowledge of operators and technicians operating in these areas, is heavily based on their experiences (strong tacit component, what is difficult to measure and articulate, and however, on numerous occasions, this break from the knowledge, can impose a high cost for the industry.

e-Learning Content Design for Corrective Maintenance of Toshiba BMC 80.5 based on Knowledge Conversion using SECI Method: A Case Study in Aerospace Company

Science.gov (United States)

Permata Shabrina, Ayu; Pramuditya Soesanto, Rayinda; Kurniawati, Amelia; Teguh Kurniawan, Mochamad; Andrawina, Luciana

2018-03-01

Knowledge is a combination of experience, value, and information that is based on the intuition that allows an organization to evaluate and combine new information. In an organization, knowledge is not only attached to document but also in routine value creating activities, therefore knowledge is an important asset for the organization. X Corp is a company that focused on manufacturing aerospace components. In carrying out the production process, the company is supported by various machines, one of the machines is Toshiba BMC 80.5. The machine is used occasionally and therefore maintenance activity is needed, especially corrective maintenance. Corrective maintenance is done to make a breakdown machine back to work. Corrective maintenance is done by maintenance operator whose retirement year is close. The long term experience of the maintenance operator needs to be captured by the organization and shared across maintenance division. E-learning is one type of media that can support and assist knowledge sharing. This research purpose is to create the e-learning content for best practice of corrective maintenance activity for Toshiba BMC 80.5 by extracting the knowledge and experience from the operator based on knowledge conversion using SECI method. The knowledge source in this research is a maintenance supervisor and a senior maintenance engineer. From the evaluation of the e-learning content, it is known that the average test score of the respondents who use the e-learning increases from 77.5 to 87.5.

Development of diagnosis and maintenance support system for nuclear power plants with flexible inference function and knowledge base edition support function

International Nuclear Information System (INIS)

Fujii, Makoto; Seki, Eiji; Tai, Ichiro; Morioka, Toshihiko

1988-01-01

For the reliable and efficient diagnosis and inspection work of the nuclear power plant equipments, 'Diagnosis and Maintenance Support System' has been developed. This system has functions to assist operators or engineers to observe and evaluate equipment conditions based on the experts' knowledge. These functions are carried out through dialogue between the system and users. This system has two subsystems: diagnosis subsystem and knowledge base edition support subsystem. To achieve the functions of diagnosis subsystem, a new method of knowledge processing for equipment diagnosis is adopted. This method is based on the concept of 'Cause Generation and Checking'. Knowledge for diagnosis is represented with modularized production rules. And each rule module consists of four different type rules with hierarchical structure. With this approach, the system is equipped with sufficient performance not only in diagnosis function but also in flexible man-machine interface. Knowledge base edition support subsystem (Graphical Rule Editor) is provided for this system. This editor has functions to display and edit the contents of knowledge base with tree structures through the graphic display. With these functions, the efficiency of constructing expert system is highly improved. By applying this system to the maintenance support of neutron monitoring system, it is proved that this system has satisfactory performance as a diagnosis and maintenance support system. (author)

Information-Based Maintenance Optimization with Focus on Predictive Maintenance (Informatiegebaseerde onderhoudsoptimalisatie met focus op predictief onderhoud)

OpenAIRE

Van Horenbeek, Adriaan

2013-01-01

This dissertation presents an information-based maintenance optimization methodology for physical assets; with focus on, but not limited to, predictive maintenance (PdM). The overall concept of information-based maintenance is that of updating maintenance decisions based on evolving knowledge of operation history and anticipated usage of the machinery, as well as the physics and dynamics of material degradation in critical machinery components. Within this concept, predictive maintenance is a...

Technical requirements on knowledge base and instrumentation system for decision making in plant operation and maintenance

International Nuclear Information System (INIS)

Kitamura, Masaharu; Yoshikawa, Shinji; Hasegawa, Makoto

1998-03-01

A series of technical surveys and studies are described in this report to examine and identify technical requirements to be posed on knowledge base and instrumentation system as the fundamental in high reliability computational decision making in operation and maintenance of nuclear power plants. Monitoring and diagnosis are focused as the important tasks among the operation/maintenance-related tasks. A concrete monitoring and diagnosis system configuration has been proposed consisting of distributed symptom database and of on-demand measurement subsystem. An prototype of the proposed system configuration has been successfully verified. (author)

Energeia of maintenance. Knowledge resource maintenance and creation of new value

International Nuclear Information System (INIS)

Iwata, Shuichi

2011-01-01

After the Fukushima accident occurred in March 2011, the intellectual energeia of maintenology (motive force of implementation) - 'arrow of information' - could be obtained by trying to establish academic agenda from uniting 'arrow of time' and 'arrow of entropy' based on historical review and then dividing characteristics of maintenance objects needed from society in the future, into content, context and measures in order to overcome this chaos. Looking at contaminated area map around Chernobyl and comparing state of Ukraine elapsed 25 years after Chernobyl accident with that of Fukushima in great social anxiety at present, various 'arrow of information' could be enumerated such as (1) openness of content of accident information and evaluation of context, (2) safety and stability of social society, (3) perfect individual's care and human right for knowing risk, (4) data literacy, (5) various risks, (6) data dissemination and (7) utilization of outsider's view. Knowledge maintenology should be expanded in the area such as (1) preservation of global environment and maintenology, (2) problem of contaminated area with radioactive materials: data science and maintenology, (3) maintenance of large artificial product: experimental science, theoretical science, computational science and maintenology, (4) maintenance of knowledge related with events having complicated causality: design science responding to various risks. As for utilization of nuclear energy, maintenance technology, which shall balance its benefit and risk of society and establish science needed for security of all human being -a raison d'etre and energeia of maintenology-, should be considered for upper structure about global energy, environment, economics and politics (including military affairs) and human society, not for respective energy system in specific country or organization. Fundamentals of energeia of maintenology shall be implemented in the same spirit of 'Yui', small mutual aid organization

Risk-based maintenance-Techniques and applications

International Nuclear Information System (INIS)

Arunraj, N.S.; Maiti, J.

2007-01-01

Plant and equipment, however well designed, will not remain safe or reliable if it is not maintained. The general objective of the maintenance process is to make use of the knowledge of failures and accidents to achieve the possible safety with the lowest possible cost. The concept of risk-based maintenance was developed to inspect the high-risk components usually with greater frequency and thoroughness and to maintain in a greater manner, to achieve tolerable risk criteria. Risk-based maintenance methodology provides a tool for maintenance planning and decision making to reduce the probability of failure of equipment and the consequences of failure. In this paper, the risk analysis and risk-based maintenance methodologies were identified and classified into suitable classes. The factors affecting the quality of risk analysis were identified and analyzed. The applications, input data and output data were studied to understand their functioning and efficiency. The review showed that there is no unique way to perform risk analysis and risk-based maintenance. The use of suitable techniques and methodologies, careful investigation during the risk analysis phase, and its detailed and structured results are necessary to make proper risk-based maintenance decisions

Use of knowledge based systems for rational reliability analysis based inspection and maintenance planning for offshore structures

International Nuclear Information System (INIS)

Tang, M.X.; Dharmavasan, S.; Peers, S.M.C.

1994-01-01

The structural integrity of fixed offshore platforms is ensured by periodic inspections. In the past, decisions made as to when, where and how to inspect have been made by engineers using rules-of-thumb and general planning heuristics. It is now hoped that more rational inspection and maintenance scheduling may be carried out by applying recently developed techniques based on structural reliability methods. However, one of the problems associated with a theoretical approach is that it is not always possible to incorporate all the constraints that are present in a practical situation. These constraints modify the decisions made for analysis data input and the interpretation of the analysis results. Knowledge based systems provide a mean of encapsulating several different forms of information and knowledge within a computer system and hence can overcome this problem. In this paper, a prototype system being developed for integrating reliability based analysis with other constraints for inspection scheduling will be described. In addition, the scheduling model and the algorithms to carry out the scheduling will be explained. Furthermore, implementation details are also given

Sensitivity of Risk-Based Maintenance Planning of Offshore Wind Turbine Farms

DEFF Research Database (Denmark)

Ambühl, Simon; Sørensen, John Dalsgaard

2017-01-01

Inspection and maintenance expenses cover a considerable part of the cost of energy from offshore wind turbines. Risk-based maintenance planning approaches are a powerful tool to optimize maintenance and inspection actions and decrease the total maintenance expenses. Risk-based planning is based...... on many input parameters, which are in reality often not completely known. This paper will assess the cost impact of this incomplete knowledge based on a case study following risk-based maintenance planning. The sensitivity study focuses on weather forecast uncertainties, incomplete knowledge about...... the needed repair time on the site as well as uncertainties about the operational range of the boat and helicopter used to access the broken wind turbine. The cost saving potential is estimated by running Crude Monte Carlo simulations. Furthermore, corrective and preventive (scheduled and condition...

Processes, dimensions and tools for the management of knowledge in industrial maintenance

Directory of Open Access Journals (Sweden)

Javier Cárcel Carrasco

2014-05-01

Full Text Available Knowledge management, implanted in some areas of the company, is usually forgotten in the own service organizations is one of the activities requiring a deep knowledge of the physical assets of the company, that influences the own reliability of the processes of exploitation, the productivity of the company and is where higher level of tacit knowledge based on the experience of the operators. This article is a review of the literature, marking processes, dimensions and tools that can be used for the management of knowledge in the field of industrial maintenance.

The role of knowledge sharing and transactive memory system on condition based maintenance policy

NARCIS (Netherlands)

Koochaki, J.; Bouwhuis, I. M.

2008-01-01

Today, Condition Based Maintenance (CBM) has reached a sophisticated level in industry and the advantages of predictive maintenance are accepted globally. However, although lots of effort has been put into improving methods and techniques in CBM, most of predictive maintenance programs fail to

Skills, rules and knowledge in aircraft maintenance: errors in context

Science.gov (United States)

Hobbs, Alan; Williamson, Ann

2002-01-01

Automatic or skill-based behaviour is generally considered to be less prone to error than behaviour directed by conscious control. However, researchers who have applied Rasmussen's skill-rule-knowledge human error framework to accidents and incidents have sometimes found that skill-based errors appear in significant numbers. It is proposed that this is largely a reflection of the opportunities for error which workplaces present and does not indicate that skill-based behaviour is intrinsically unreliable. In the current study, 99 errors reported by 72 aircraft mechanics were examined in the light of a task analysis based on observations of the work of 25 aircraft mechanics. The task analysis identified the opportunities for error presented at various stages of maintenance work packages and by the job as a whole. Once the frequency of each error type was normalized in terms of the opportunities for error, it became apparent that skill-based performance is more reliable than rule-based performance, which is in turn more reliable than knowledge-based performance. The results reinforce the belief that industrial safety interventions designed to reduce errors would best be directed at those aspects of jobs that involve rule- and knowledge-based performance.

A basic condition-based maintenance strategy for air-cooled turbine generators

International Nuclear Information System (INIS)

Laird, T.; Griffith, G.; Hoof, M.

2005-01-01

This paper discusses the methods of using condition-based maintenance (CBM) for turbine generators. Even though it is focused on the maintenance strategy for air-cooled generators, all types of power producers can realize benefits from a better maintenance strategy at lower costs. A reliable assessment of the actual unit condition requires detailed knowledge of the unit design, operational weaknesses, cost of maintenance and operational capabilities. (author)

Maintenance of nuclear knowledge in an antinuclear environment

International Nuclear Information System (INIS)

Boeck, H.; Villa, M.

2008-01-01

In this work authors present the maintenance of nuclear knowledge in an antinuclear environment in Austria. Participation of the TRIGA Mark II research reactor in the Atominstitut in different courses, in research projects and education is presented.

Radiation protection optimization using a knowledge based methodology

International Nuclear Information System (INIS)

Reyes-Jimenez, J.; Tsoukalas, L.H.

1991-01-01

This paper presents a knowledge based methodology for radiological planning and radiation protection optimization. The cost-benefit methodology described on International Commission of Radiation Protection Report No. 37 is employed within a knowledge based framework for the purpose of optimizing radiation protection and plan maintenance activities while optimizing radiation protection. 1, 2 The methodology is demonstrated through an application to a heating ventilation and air conditioning (HVAC) system. HVAC is used to reduce radioactivity concentration levels in selected contaminated multi-compartment models at nuclear power plants when higher than normal radiation levels are detected. The overall objective is to reduce personnel exposure resulting from airborne radioactivity, when routine or maintenance access is required in contaminated areas. 2 figs, 15 refs

Condition based maintenance in the context of opportunistic maintenance

NARCIS (Netherlands)

Koochaki, Javid; Bokhorst, Jos A. C.; Wortmann, Hans; Klingenberg, Warse

2012-01-01

Condition based maintenance (CBM) uses the operating condition of a component to predict a failure event. Compared to age based replacement (ABR), CBM usually results in higher availability and lower maintenance costs, since it tries to prevent unplanned downtime and avoid unnecessary preventive

KBTAC: EPRI's center to assist the nuclear industry to apply the knowledge-based technology

International Nuclear Information System (INIS)

Lin, Chinglu; Naser, J.A.; Sun, B.K.H.

1993-01-01

The nuclear utility industry's complex engineering and procedure systems offer many opportunities for use of the knowledge-based technology such as expert systems and neural networks. The ability of expert systems to enhance human experts makes them an important tool in the areas of engineering, operations and maintenance. However, many current industry applications are research projects or turnkey systems supplied by vendors. These often do not impart to utility technical staff a clear understanding of the capabilities of knowledge-based systems (KBS). More importantly, simply using completed applications does not meet utilities' need to acquire the capabilities to build their own knowledge-based systems. Thus, EPRI is supporting its member utilities utilization of knowledge-based technology for power plant engineering, operations, and maintenance applications through the establishment of the Knowledge-Based Technology Application Center (KBTAC)

Knowledge lost in data : Organizational impediments to condition-based maintenance in the process industry

NARCIS (Netherlands)

van de Kerkhof, Roland; Akkermans, Henk; Noorderhaven, Niels; Zijm, H.; Klumpp, M.; Clausen, U.; Ten Hompel, M.

2016-01-01

In this chapter we report on a pilot study of Condition-Based Maintenance (CBM) in the process industries, such as the steelmaking- and chemical industries, and propose a diagnostic instrument for systematically analysing the challenges to the successful implementation and execution of a CBM

Advanced Maintenance Simulation by Means of Hand-Based Haptic Interfaces

Science.gov (United States)

Nappi, Michele; Paolino, Luca; Ricciardi, Stefano; Sebillo, Monica; Vitiello, Giuliana

Aerospace industry has been involved in virtual simulation for design and testing since the birth of virtual reality. Today this industry is showing a growing interest in the development of haptic-based maintenance training applications, which represent the most advanced way to simulate maintenance and repair tasks within a virtual environment by means of a visual-haptic approach. The goal is to allow the trainee to experiment the service procedures not only as a workflow reproduced at a visual level but also in terms of the kinaesthetic feedback involved with the manipulation of tools and components. This study, conducted in collaboration with aerospace industry specialists, is aimed to the development of an immersive virtual capable of immerging the trainees into a virtual environment where mechanics and technicians can perform maintenance simulation or training tasks by directly manipulating 3D virtual models of aircraft parts while perceiving force feedback through the haptic interface. The proposed system is based on ViRstperson, a virtual reality engine under development at the Italian Center for Aerospace Research (CIRA) to support engineering and technical activities such as design-time maintenance procedure validation, and maintenance training. This engine has been extended to support haptic-based interaction, enabling a more complete level of interaction, also in terms of impedance control, and thus fostering the development of haptic knowledge in the user. The user’s “sense of touch” within the immersive virtual environment is simulated through an Immersion CyberForce® hand-based force-feedback device. Preliminary testing of the proposed system seems encouraging.

APPLICATION OF ROUGH SET THEORY TO MAINTENANCE LEVEL DECISION-MAKING FOR AERO-ENGINE MODULES BASED ON INCREMENTAL KNOWLEDGE LEARNING

Institute of Scientific and Technical Information of China (English)

陆晓华; 左洪福; 蔡景

2013-01-01

The maintenance of an aero-engine usually includes three levels ,and the maintenance cost and period greatly differ depending on the different maintenance levels .To plan a reasonable maintenance budget program , airlines would like to predict the maintenance level of aero-engine before repairing in terms of performance parame-ters ,which can provide more economic benefits .The maintenance level decision rules are mined using the histori-cal maintenance data of a civil aero-engine based on the rough set theory ,and a variety of possible models of upda-ting rules produced by newly increased maintenance cases added to the historical maintenance case database are in-vestigated by the means of incremental machine learning .The continuously updated rules can provide reasonable guidance suggestions for engineers and decision support for planning a maintenance budget program before repai-ring .The results of an example show that the decision rules become more typical and robust ,and they are more accurate to predict the maintenance level of an aero-engine module as the maintenance data increase ,which illus-trates the feasibility of the represented method .

A proactive condition-based maintenance strategy with both perfect and imperfect maintenance actions

International Nuclear Information System (INIS)

Do, Phuc; Voisin, Alexandre; Levrat, Eric; Iung, Benoit

2015-01-01

This paper deals with a proactive condition-based maintenance (CBM) considering both perfect and imperfect maintenance actions for a deteriorating system. Perfect maintenance actions restore completely the system to the ‘as good as new’ state. Their related cost are however often high. The first objective of the paper is to investigate the impacts of imperfect maintenance actions. In fact, both positive and negative impacts are considered. Positive impact means that the imperfect maintenance cost is usually low. Negative impact implies that (i) the imperfect maintenance restores a system to a state between good-as-new and bad-as-old and (ii) each imperfect preventive action may accelerate the speed of the system's deterioration process. The second objective of the paper is to propose an adaptive maintenance policy which can help to select optimally maintenance actions (perfect or imperfect actions), if needed, at each inspection time. Moreover, the time interval between two successive inspection points is determined according to a remaining useful life (RUL) based-inspection policy. To illustrate the use of the proposed maintenance policy, a numerical example finally is introduced. - Highlights: • A new imperfect maintenance model for deterioration system is proposed. • Both positive and negative impacts of an imperfect maintenance action are investigated. • An adaptive condition-based maintenance policy is introduced. • The optimal number of useful imperfect maintenance actions for each life cycle is optimally provided

Software evolution and maintenance

CERN Document Server

Tripathy, Priyadarshi

2014-01-01

Software Evolution and Maintenance: A Practitioner's Approach is an accessible textbook for students and professionals, which collates the advances in software development and provides the most current models and techniques in maintenance.Explains two maintenance standards: IEEE/EIA 1219 and ISO/IEC14764Discusses several commercial reverse and domain engineering toolkitsSlides for instructors are available onlineInformation is based on the IEEE SWEBOK (Software Engineering Body of Knowledge)

Advantages of condition-based maintenance approach

International Nuclear Information System (INIS)

Bareiss, J.; Roos, E.; Jovanovic, A.; Perunicic, M.; Balos, D.

2004-01-01

Pilot applications in EnBW steam boiler components and high-pressure pipe systems in the context of the European research project RIMAP (''Risk Based Inspection and Maintenance Procedures for European Industry'') showed that application of a risk-based maintenance strategy (e.g. RIMAP) will make the decision process more transparent and enable better condition-oriented maintenance. With regard to life management of the systems (availability, product quality), this appears to be more important than than the aspect of cost reduction in the maintenance sector, although the latter may not be unwelcome. (orig.) [de

Knowledge-Based Systems for the Assessment and Management of Bridge Structures

DEFF Research Database (Denmark)

Miyamoto, A.; Thoft-Christensen, Palle; Yan, B.

2004-01-01

. The aim of this paper is to summarize the finding of up-to-date research articles concerning the application of knowledge-based systems to assessment and management of structures and to illustrate the potential of such systems in the structural engineering. Two modern bridge management systems (BMS......It is becoming an important social problem to make maintenance and rehabilitation of existing infrastructures such as bridges, buildings, etc. The kernel of such structure management is to develop a method of safety assessment on items which include remaining life and load carrying capacity......'s) are presented in the paper. The first is a BMS to assess the performance and derive optimal strategies for inspection and maintenance of concrete structures using reliability based and knowledge based systems. The second is the concrete bridge rating expert system (BREX) to evaluate the performance of existing...

Condition based maintenance pilot projects at Pickering ND

International Nuclear Information System (INIS)

Zemdegs, R.T.

1995-01-01

Ontario Hydro has recognized that the approaches to maintenance have undergone significant changes to the past decades. The traditional break down maintenance approach has been replaced by preventative maintenance and more recently, by condition based maintenance. The nuclear plants of Ontario Hydro have evaluated on a number of alternative programs to improve their maintenance effectiveness and to reduce costs, including Reliability Centred Maintenance (RCM), call-up review, component-based PM programs, analysis of failure history and so on. Pickering ND (nuclear division) and Ontario Hydro's Nuclear Technologies Services Division, have embarked on a Condition Based Maintenance pilot project to address the above issues as a breakthrough solution for smarter maintenance. The Condition Based Maintenance pilot project will demonstrate an end-to-end process utilizing a Reliability Centred Maintenance structured approach to re-engineer and redefine the existing maintenance programs. The project emphasizes on-condition maintenance where justified, and utilizes an information management tool to provide the required records keeping and analysis infrastructure. This paper briefly describes the planned maintenance model at Pickering ND used to guide the CBM pilot, and an overview of the methodology used to develop on-condition equipment indicators as part of a re-engineered maintenance plan

Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

International Nuclear Information System (INIS)

Sanchez, Ana; Carlos, Sofia; Martorell, Sebastian; Villanueva, Jose F.

2009-01-01

Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral

Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

Energy Technology Data Exchange (ETDEWEB)

Sanchez, Ana [Department of Statistics and Operational Research, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Carlos, Sofia [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Martorell, Sebastian [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)], E-mail: smartore@iqn.upv.es; Villanueva, Jose F. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)

2009-01-15

Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral.

Structural design systems using knowledge-based techniques

International Nuclear Information System (INIS)

Orsborn, K.

1993-01-01

Engineering information management and the corresponding information systems are of a strategic importance for industrial enterprises. This thesis treats the interdisciplinary field of designing computing systems for structural design and analysis using knowledge-based techniques. Specific conceptual models have been designed for representing the structure and the process of objects and activities in a structural design and analysis domain. In this thesis, it is shown how domain knowledge can be structured along several classification principles in order to reduce complexity and increase flexibility. By increasing the conceptual level of the problem description and representation of the domain knowledge in a declarative form, it is possible to enhance the development, maintenance and use of software for mechanical engineering. This will result in a corresponding increase of the efficiency of the mechanical engineering design process. These ideas together with the rule-based control point out the leverage of declarative knowledge representation within this domain. Used appropriately, a declarative knowledge representation preserves information better, is more problem-oriented and change-tolerant than procedural representations. 74 refs

Development of the CAI system for inheritance of maintenance expertise

International Nuclear Information System (INIS)

Hanafusa, Hidemitsu; Chigusa, Naoki; Furuta, Kazuo

2002-01-01

High quality maintenance is required in order to secure the safety of nuclear power plants. The engineers engaged in maintenance activities have to master various knowledge, including the explicit and tacit knowledge of experienced experts, through education and training. Moreover, it is also very important to prevent these knowledge from getting scattered and lost with a change of generation and to share the knowledge or expertise. The purpose of this study is to develop a support system for the next generation experts to help them master and make use of the knowledge of their predecessors. The knowledge or expertise consist of ''knowledge about the maintenance tasks'', ''knowledge about structure/function of plant system/equipment'', and ''individual knowledge based on trouble experience etc.''. The ways this knowledge could be represented were considered first, then this support system was developed based on such representation. (author)

Application of plant Technology Knowledge Infrastructure to plant engineering and maintenance

International Nuclear Information System (INIS)

Kawanaka, Tsutomu; Tamaki, Yuji; Ota, Yoshimi; Yoshinaga, Toshiaki

2006-01-01

Management and maintenance tools are now greatly available for contributing reduction of maintenance cost and time. These tools surely give us much benefit, but are only for maintaining reliabilities of the equipment. Reliability of the plant depends on the design and actual operating conditions. Accordingly, the matter to do first is to consider facilities in the range of the plant life cycle. This brings the result that 'process property' and 'functional property' are required besides 'equipment property' which has been used for the evaluation index. Because these properties are formed at the designing stage, the beginning of the life cycle, and by applying the equipment function to them, maintenance cost can be reduced without risk increasing. To execute this subject, it is strongly required to accumulate information and data, to build up the Technology Knowledge Infrastructure. This paper reports the system and the way of applying the method to the actual plants. (author)

Collaborative learning in condition based maintenance

NARCIS (Netherlands)

Koochaki, J.; Ao, SI; Gelman, L; Hukins, DWL; Hunter, A; Korsunsky, AM

2009-01-01

In recent years, the importance of reliable and consistent production equipments has increased. As a result, companies are shifting their maintenance policy from preventive maintenance towards Condition Based Maintenance (CBM). Despite the growing trend in this area and success stories of CBM

Knowledge management: An abstraction of knowledge base and database management systems

Science.gov (United States)

Riedesel, Joel D.

1990-01-01

Artificial intelligence application requirements demand powerful representation capabilities as well as efficiency for real-time domains. Many tools exist, the most prevalent being expert systems tools such as ART, KEE, OPS5, and CLIPS. Other tools just emerging from the research environment are truth maintenance systems for representing non-monotonic knowledge, constraint systems, object oriented programming, and qualitative reasoning. Unfortunately, as many knowledge engineers have experienced, simply applying a tool to an application requires a large amount of effort to bend the application to fit. Much work goes into supporting work to make the tool integrate effectively. A Knowledge Management Design System (KNOMAD), is described which is a collection of tools built in layers. The layered architecture provides two major benefits; the ability to flexibly apply only those tools that are necessary for an application, and the ability to keep overhead, and thus inefficiency, to a minimum. KNOMAD is designed to manage many knowledge bases in a distributed environment providing maximum flexibility and expressivity to the knowledge engineer while also providing support for efficiency.

Adding Learning to Knowledge-Based Systems: Taking the "Artificial" Out of AI

Science.gov (United States)

Daniel L. Schmoldt

1997-01-01

Both, knowledge-based systems (KBS) development and maintenance require time-consuming analysis of domain knowledge. Where example cases exist, KBS can be built, and later updated, by incorporating learning capabilities into their architecture. This applies to both supervised and unsupervised learning scenarios. In this paper, the important issues for learning systems-...

Expert system for maintenance of nuclear power plants

International Nuclear Information System (INIS)

Ito, Tetsuo; Kasahara, Takayasu; Watanabe, Takao; Matsuki, Tsutomu.

1989-01-01

The basic function of the expert system which supports the maintenance works such as the diagnosis of nuclear power plants and the planning of maintenance works was developed. For the maintenance of large scale plants like nuclear power plants, much manpower is required. Consequently, it has been desired to develop the system for improving the maintainability by utilizing the expertise and empirical knowledge of skilled engineers. This system comprises the subsystems for aiding plant diagnosis and maintenance work planning. The former diagnoses the contents of out of order based on the knowledge base, and thereafter, guides the method of taking measures using simulator. The latter establishes the plan by using the method of limiting branching together so that the maintenance works do not interfere mutually or do not affect the operation. Hereafter, it is intended to improve the man-machine condition and expand knowledge aiming at the practical use. The outline of the system, the constitution of subsystems, the example of plant diagnosis, the support of plant maintenance work planning and so on are reported. (K.I.)

Equipment Maintenance management support system based on statistical analysis of maintenance history data

International Nuclear Information System (INIS)

Shimizu, S.; Ando, Y.; Morioka, T.

1990-01-01

Plant maintenance is recently becoming important with the increase in the number of nuclear power stations and in plant operating time. Various kinds of requirements for plant maintenance, such as countermeasures for equipment degradation and saving maintenance costs while keeping up plant reliability and productivity, are proposed. For this purpose, plant maintenance programs should be improved based on equipment reliability estimated by field data. In order to meet these requirements, it is planned to develop an equipment maintenance management support system for nuclear power plants based on statistical analysis of equipment maintenance history data. The large difference between this proposed new method and current similar methods is to evaluate not only failure data but maintenance data, which includes normal termination data and some degree of degradation or functional disorder data for equipment and parts. So, it is possible to utilize these field data for improving maintenance schedules and to evaluate actual equipment and parts reliability under the current maintenance schedule. In the present paper, the authors show the objectives of this system, an outline of this system and its functions, and the basic technique for collecting and managing of maintenance history data on statistical analysis. It is shown, from the results of feasibility tests using simulation data of maintenance history, that this system has the ability to provide useful information for maintenance and the design enhancement

Basic principles of knowledge management and its application to the industrial company in tactical operations of maintenance and operational exploitation: A qualitative study

Directory of Open Access Journals (Sweden)

Francisco Javier Cárcel Carrasco

2013-01-01

Full Text Available Purpose: Although knowledge and its management is, and has been, studied in depth, particularly since the 90’s decade of the past century, especially for the strategic management, innovation, trade, or business administration, there are still many questions on how it articulates or transfers and the barriers to its management, especially when we talk about internal tactical activities that affect staff that we could call "offices", such as maintenance and industrial assembly or exploitation and conduction of the facilities. Because of the peculiarities normally seen in this kind of activity in the industrial companies, the knowledge of these people is strongly based on their experience (strong tacit component, difficult to measure and articulate, and on many occasions, however, this rupture of information-knowledge, can represent a high cost for the company (often assumed to be something inevitable due to the increase in production and service downtime, loss of efficiency, or tuning time of new staff to these areas.Design/methodology/approach: After a description of the State of the art and the basic principles of knowledge management, a qualitative study in an industrial company has been carried out, within the areas of operation and maintenance, in order to know the barriers and facilitators that such involved personnel finds in order to achieve an adequate transmission and use of that knowledge.Findings and Originality/value: Learn about barriers, facilitators and impact that offers the knowledge management in the areas of industrial maintenance, especially among professionals in offices which operate with a high degree of tacit knowledge and with a heavy dependence on the company on these professionals.Research limitations/implications: Those characteristics of a qualitative study in a particular area and within a geographical area, although it can be extrapolated to other types of companies and regional areas.Practical implications: Learn

Maintenance Staffing Standards for Zero-Based Budgeting.

Science.gov (United States)

Adams, Matthew C.; And Others

1998-01-01

Discusses school preventive maintenance and the variables associated with maintenance staffing standards that address a zero-based budgeting environment. Explores preventive-maintenance measurement for staffing requirements, defines staffing levels and job descriptions, and outlines the factors to consider when creating a maintenance program and…

Development of an integrated knowledge-base and its management tool for computerized alarm processing system

International Nuclear Information System (INIS)

Heo, Gyun Young; Choi, Seong Soo; Kim, Han Gon; Chang, Soon Heung

1997-01-01

For a long time, a number of alarm processing techniques have been researched to reduce the number of actuated alarms for operators to deal with effectively during the abnormal as well as the normal conditions. However, the strategy that the only systems with a few clear technologies should be used as a part of an alarm annunciation system has been adopted considering the effectiveness and the reliability in actual alarm processing systems. Therefore, alarm processing systems have difficult knowledge-base maintenance problems and limited expansion or enhancement defects. To solve these shortcomings, the integrated knowledge-base which can express the general information related to all the alarm processing techniques is proposed and its management tool, Knowledge Input Tool for Alarm (KIT-A) which can handle the data of the knowledge-base efficiently is developed. Since the integrated knowledge-base with KIT-A can manipulate all the alarm information without the modification of alarm processing system itself, it is expected to considerably advance the overall capability of maintenance and enhancement of the alarm processing systems

Case Based Asset Maintenance for the Electric Equipment

International Nuclear Information System (INIS)

Kim, Ji-Hyeon; Jung, Jae-Cheon; Chang, Young-Woo; Chang, Hoon-Seon; Kim, Jae-Cheol; Kim, Hang-Bae; Kim, Kyu-Ho; Hur, Yong; Lee, Dong-Chul

2006-01-01

The electric equipment maintenance strategies are changing from PM(Preventive Maintenance) or CM(Corrective Maintenance) to CBM(Condition Based Maintenance). The main benefits of CBM are reduced possibility of service failures of critical equipment and reduced costs or maintenance work. In CBM, the equipment status need to be monitored continuously and a decision should be made whether an equipment need to be repaired or replaced. For the maintenance decision making, the CBR(Case Base Reasoning) system is introduced. The CBR system receives the current equipment status and retrieves the case based historic database to determine any possible equipment failure under current conditions. In retrieving the case based historic data, the suggested DSS(Decision Support System) uses a reasoning engine with an equipment/asset ontology that describes the equipment subsumption relationships

Structural health monitoring methodology for aircraft condition-based maintenance

Science.gov (United States)

Saniger, Jordi; Reithler, Livier; Guedra-Degeorges, Didier; Takeda, Nobuo; Dupuis, Jean Pierre

2001-06-01

Reducing maintenance costs while keeping a constant level of safety is a major issue for Air Forces and airlines. The long term perspective is to implement condition based maintenance to guarantee a constant safety level while decreasing maintenance costs. On this purpose, the development of a generalized Structural Health Monitoring System (SHMS) is needed. The objective of such a system is to localize the damages and to assess their severity, with enough accuracy to allow low cost corrective actions. The present paper describes a SHMS based on acoustic emission technology. This choice was driven by its reliability and wide use in the aerospace industry. The described SHMS uses a new learning methodology which relies on the generation of artificial acoustic emission events on the structure and an acoustic emission sensor network. The calibrated acoustic emission events picked up by the sensors constitute the knowledge set that the system relies on. With this methodology, the anisotropy of composite structures is taken into account, thus avoiding the major cause of errors of classical localization methods. Moreover, it is adaptive to different structures as it does not rely on any particular model but on measured data. The acquired data is processed and the event's location and corrected amplitude are computed. The methodology has been demonstrated and experimental tests on elementary samples presented a degree of accuracy of 1cm.

Component-Based Data-Driven Predictive Maintenance to Reduce Unscheduled Maintenance Events

NARCIS (Netherlands)

Verhagen, W.J.C.; Curran, R.; de Boer, L.W.M.; Chen, C.H.; Trappey, A.C.; Peruzzini, M.; Stjepandić, J.; Wognum, N.

2017-01-01

Costs associated with unscheduled and preventive maintenance can contribute significantly to an airline's expenditure. Reliability analysis can help to identify and plan for maintenance events. Reliability analysis in industry is often limited to statistically based

Performance-based inspection and maintenance strategies

International Nuclear Information System (INIS)

Vesely, W.E.

1995-01-01

Performance-based inspection and maintenance strategies utilize measures of equipment performance to help guide inspection and maintenance activities. A relevant measure of performance for safety system components is component unavailability. The component unavailability can also be input into a plant risk model such as a Probabilistic Risk Assessment (PRA) to determine the associated plant risk performance. Based on the present and projected unavailability performance, or the present and projected risk performance, the effectiveness of current maintenance activities can be evaluated and this information can be used to plan future maintenance activities. A significant amount of information other than downtimes or failure times is collected or can be collected when an inspection or maintenance is conducted which can be used to estimate the component unavailability. This information generally involves observations on the condition or state of the component or component piecepart. The information can be detailed such as the amount of corrosion buildup or can be general such as the general state of the component described as ' high degradation', ' moderate degradation', or ' low degradation'. Much of the information collected in maintenance logs is qualitative and fuzzy. As part of an NRC Research program on performance-based engineering modeling, approaches have been developed to apply Fuzzy Set Theory to information collected on the state of the component to determine the implied component or component piecepart unavailability. Demonstrations of the applications of Fuzzy Set Theory are presented utilizing information from plant maintenance logs. The demonstrations show the power of Fuzzy Set Theory in translating engineering information to reliability and risk implications

Cost savings from performance-based maintenance contracting

NARCIS (Netherlands)

Straub, A.

2009-01-01

New procurement approaches combined with performance-based building approaches should reduce costs, but empirical qualitative and quantitative studies are lacking. Performance-based maintenance contracts give maintenance suppliers incentives to improve their way of working. Innovative,

Discounted cost model for condition-based maintenance optimization

International Nuclear Information System (INIS)

Weide, J.A.M. van der; Pandey, M.D.; Noortwijk, J.M. van

2010-01-01

This paper presents methods to evaluate the reliability and optimize the maintenance of engineering systems that are damaged by shocks or transients arriving randomly in time and overall degradation is modeled as a cumulative stochastic point process. The paper presents a conceptually clear and comprehensive derivation of formulas for computing the discounted cost associated with a maintenance policy combining both condition-based and age-based criteria for preventive maintenance. The proposed discounted cost model provides a more realistic basis for optimizing the maintenance policies than those based on the asymptotic, non-discounted cost rate criterion.

Single-stage Kanban system with deterioration failures and condition-based preventive maintenance

International Nuclear Information System (INIS)

Xanthopoulos, A.S.; Koulouriotis, D.E.; Botsaris, P.N.

2015-01-01

Despite the fact that the fields of pull type production control policies and condition-based preventive maintenance have much in common contextually, they have evolved independently up to now. In this investigation, an attempt is made to bridge the gap between these two branches of knowledge by introducing the single-stage Kanban system with deterioration failures and condition-based preventive maintenance. The formalism of continuous time Markov chains is used to model the system and expressions for eight performance metrics are derived. Two important, from a managerial perspective, constrained optimization problems for the proposed model are defined where the objective is the simultaneous optimization of the Kanban policy, the preventive maintenance policy and the inspection schedule under conflicting performance criteria. Multiple instances of each optimization problem are solved by means of the augmented Lagrangian genetic algorithm. The results from the optimization trials coupled by the results from extensive numerical examples facilitate the thorough investigation of the system’s behaviour. - Highlights: • Kanban system with deterioration failures and preventive maintenance is introduced. • The system is modeled as a continuous time Markov chain. • Expressions for eight performance metrics are derived. • The behavior of the system is studied through numerical examples. • Optimization results for selected performance metrics are presented

KBTAC [Knowledge-Based Technology Application Center] - The EPRI [Electric Power Research Institute]-sponsored knowledge-based technology application center

International Nuclear Information System (INIS)

Meyer, W.; Wood, R.M.; Scherer, J.

1990-01-01

The Electric Power Research Institute (EPRI) has announced the establishment of the Knowledge-Based Technology Application Center (KBTAC), whose goal is to assist member utilities with expert system technology and applications. The center, established November 7, 1989, is located on the campus of Syracuse University, Syracuse, New York, and will be operated jointly by Kaman Sciences Corporation and the university. The mission of the KBTAC is to assist EPRI member utilities to develop, test, and transfer expert systems into nuclear power plant operations, maintenance, and administration

Maintenance evaluation using risk based criteria

International Nuclear Information System (INIS)

Torres Valle, A.

1996-01-01

The maintenance evaluation is currently performed by using economic and, in some case, technical equipment failure criteria, however this is done to a specific equipment level. In general, when statistics are used the analysis for maintenance optimization are made isolated and whit a post mortem character; The integration provided by mean of Probabilistic Safety assessment (PSA) together with the possibilities of its applications, allow for evaluation of maintenance on the basis of broader scope criteria in regard to those traditionally used. The evaluate maintenance using risk based criteria, is necessary to follow a dynamic and systematic approach, in studying the maintenance strategy, to allow for updating the initial probabilistic models, for including operational changes that often take place during operation of complex facilities. This paper proposes a dynamic evaluation system of maintenance task. The system is illustrated by means of a practical example

Ageing Management Based Maintenance at ETRR-II

Energy Technology Data Exchange (ETDEWEB)

Kamoon, A.; Ali, A., E-mail: akamoun2004@yahoo.com [Inshas Nuclear Research Centre, Egyptian Atomic Energy Authority (EAEA), Cairo (Egypt)

2014-08-15

The second research reactor of Egypt, ETRR-II, is an open pool type multi-purpose reactor of 22 MW that has been in operation since 1998. The main purposes of ETRR-II are the production of radioisotopes, personnel training, research and development. Ageing management of ETRR-II is based on the maintenance programme. This programme was planned to have a proactive maintenance strategy that mainly depends on adequate preventive and predictive maintenance. Screening of SSCs is based on safety classes, needs and quality levels. The operation condition and maintenance history are the basis to assess the level of degradation. The ultimate aim of the maintenance team is to perform adequate maintenance work only when it is really necessary. The objectives of the ageing management based maintenance are to maintain and improve equipment availability, confirm compliance with operational limits and conditions, and detect and correct any abnormal condition that might affect reactor safety. The programme also helps to detect trends in ageing so that a plan for mitigating ageing effects can be prepared and implemented. Reactor service conditions are monitored through many parameters and conditions such as conductivity and pH of coolant water, water radiochemical analysis, thermal and hydraulic parameters, a leak detection system, corrosion rate of piping, vibration level of rotating equipment and control rod drop time.

Hypertext-based integration for nuclear plant maintenance and operations

International Nuclear Information System (INIS)

Tsoukalas, L.H.; Upadhyaya, B.R.

1991-01-01

A methodology is presented that uses fuzzy graphs in the emerging paradigm of hypertext for the purpose of integrating data, information and multifaceted knowledge resources abounding in power plant operations and maintenance. A hypertext system is viewed as a set of nodes and links where with each link we associate membership functions embodying context-dependent criteria for navigating large information spaces. A general framework for navigation is outlined and graph-theory navigational tools are developed. A numerical example and a HyperCard-based prototype for monitoring special material in the MHTGR-NPR are included. 10 refs., 12 figs

Tackling the knowledge needs of maintenance and operation staff in mouldy housing

DEFF Research Database (Denmark)

Bonderup, Sirid; Gunnarsen, Lars Bo

2017-01-01

Interdisciplinary collaboration is key when it comes to solving and preventing mould problems in housing. Many forms of collaboration is necessary, not just between operating staff, inhabitants, management and tradespersons, but also knowing and working with the building structure in question...... discussed how a digital tool could help operating staff gather, share and systematise knowledge of local conditions and practices in order to improve operation and maintenance....

An Intelligent Fleet Condition-Based Maintenance Decision Making Method Based on Multi-Agent

OpenAIRE

Bo Sun; Qiang Feng; Songjie Li

2012-01-01

According to the demand for condition-based maintenance online decision making among a mission oriented fleet, an intelligent maintenance decision making method based on Multi-agent and heuristic rules is proposed. The process of condition-based maintenance within an aircraft fleet (each containing one or more Line Replaceable Modules) based on multiple maintenance thresholds is analyzed. Then the process is abstracted into a Multi-Agent Model, a 2-layer model structure containing host negoti...

An Intelligent Fleet Condition-Based Maintenance Decision Making Method Based on Multi-Agent

Directory of Open Access Journals (Sweden)

Bo Sun

2012-01-01

Full Text Available According to the demand for condition-based maintenance online decision making among a mission oriented fleet, an intelligent maintenance decision making method based on Multi-agent and heuristic rules is proposed. The process of condition-based maintenance within an aircraft fleet (each containing one or more Line Replaceable Modules based on multiple maintenance thresholds is analyzed. Then the process is abstracted into a Multi-Agent Model, a 2-layer model structure containing host negotiation and independent negotiation is established, and the heuristic rules applied to global and local maintenance decision making is proposed. Based on Contract Net Protocol and the heuristic rules, the maintenance decision making algorithm is put forward. Finally, a fleet consisting of 10 aircrafts on a 3-wave continuous mission is illustrated to verify this method. Simulation results indicate that this method can improve the availability of the fleet, meet mission demands, rationalize the utilization of support resources and provide support for online maintenance decision making among a mission oriented fleet.

Knowledge based ranking algorithm for comparative assessment of post-closure care needs of closed landfills

International Nuclear Information System (INIS)

Sizirici, Banu; Tansel, Berrin; Kumar, Vivek

2011-01-01

Post-closure care (PCC) activities at landfills include cap maintenance; water quality monitoring; maintenance and monitoring of the gas collection/control system, leachate collection system, groundwater monitoring wells, and surface water management system; and general site maintenance. The objective of this study was to develop an integrated data and knowledge based decision making tool for preliminary estimation of PCC needs at closed landfills. To develop the decision making tool, 11 categories of parameters were identified as critical areas which could affect future PCC needs. Each category was further analyzed by detailed questions which could be answered with limited data and knowledge about the site, its history, location, and site specific characteristics. Depending on the existing knowledge base, a score was assigned to each question (on a scale 1-10, as 1 being the best and 10 being the worst). Each category was also assigned a weight based on its relative importance on the site conditions and PCC needs. The overall landfill score was obtained from the total weighted sum attained. Based on the overall score, landfill conditions could be categorized as critical, acceptable, or good. Critical condition indicates that the landfill may be a threat to the human health and the environment and necessary steps should be taken. Acceptable condition indicates that the landfill is currently stable and the monitoring should be continued. Good condition indicates that the landfill is stable and the monitoring activities can be reduced in the future. The knowledge base algorithm was applied to two case study landfills for preliminary assessment of PCC performance.

On condition based maintenance policy

Directory of Open Access Journals (Sweden)

Jong-Ho Shin

2015-04-01

Full Text Available In the case of a high-valuable asset, the Operation and Maintenance (O&M phase requires heavy charges and more efforts than the installation (construction phase, because it has long usage life and any accident of an asset during this period causes catastrophic damage to an industry. Recently, with the advent of emerging Information Communication Technologies (ICTs, we can get the visibility of asset status information during its usage period. It gives us new challenging issues for improving the efficiency of asset operations. One issue is to implement the Condition-Based Maintenance (CBM approach that makes a diagnosis of the asset status based on wire or wireless monitored data, predicts the assets abnormality, and executes suitable maintenance actions such as repair and replacement before serious problems happen. In this study, we have addressed several aspects of CBM approach: definition, related international standards, procedure, and techniques with the introduction of some relevant case studies that we have carried out.

A development of maintenance educational support method by using navigation method. Pt. 1. A conceptual design of RHR pump maintenance educational support prototype system

International Nuclear Information System (INIS)

Yoshino, Kenji; Hirotsu, Yuko; Fujimoto, Junzo; Gouda, Hidenori

2001-01-01

The purpose of this research is before hand prevention of the systematic error produced from the fault of command / command system on the different organization in a nuclear power plant, and the individual error of the demand level of maintenance work, and knowledge and experience level of a maintenance worker produced from it being incongruent (mismatch), and generating of the serious accident and a serious trouble. This research attains optimization with the difficulty of maintenance work, and work execution capability, such as the persons concerned (a supervision person, a construction person, work person), and proposes the new 'maintenance educational support technique' which is useful to the improvement in 'work reliability' and 'before hand prevention of a human error' in the maintenance work spot. The main results concerning this research are shown below. (1) In this research, concept design of RHR pump maintenance work educational support prototype system was performed on the basis of the examination result of a process analysis of RHR pump maintenance work, load mapping, a rule base/knowledge base and a data base/filing system. Consequently, when an educator-ed talked with a data base/filing system along with load mapping of maintenance work (Why, How, What), a possibility that it could reach exactly from work start to the sub goal or the last goal and timely was suggested. (2) As a result of classifying 'the difficulty of maintenance work', and man's work execution capability' and comparing the result using SRK (behavior of human) index which Rasmussen proposed, among both, it turns out that difference (inharmonious) arises. The exact presentation of the educational method or educational material which responded to knowledge and experience level of an educational achievement target or an educator-ed can be referred to as being connected with the improvement in work reliability, and before hand prevention of a human error as a result by then, incorporating

Study on large scale knowledge base with real time operation for autonomous nuclear power plant. 1. Basic concept and expecting performance

International Nuclear Information System (INIS)

Ozaki, Yoshihiko; Suda, Kazunori; Yoshikawa, Shinji; Ozawa, Kenji

1996-04-01

Since it is desired to enhance availability and safety of nuclear power plants operation and maintenance by removing human factor, there are many researches and developments for intelligent operation or diagnosis using artificial intelligence (AI) technique. We have been developing an autonomous operation and maintenance system for nuclear power plants by substituting AI's and intelligent robots. It is indispensable to use various and large scale knowledge relative to plant design, operation, and maintenance, that is, whole life cycle data of the plant for the autonomous nuclear power plant. These knowledge must be given to AI system or intelligent robots adequately and opportunely. Moreover, it is necessary to insure real time operation using the large scale knowledge base for plant control and diagnosis performance. We have been studying on the large scale and real time knowledge base system for autonomous plant. In the report, we would like to present the basic concept and expecting performance of the knowledge base for autonomous plant, especially, autonomous control and diagnosis system. (author)

Application of knowledge based software to industrial automation in Japan

International Nuclear Information System (INIS)

Matsumoto, Yoshihiro

1985-01-01

In Japan, large industrial undertakings such as electric utilities or steel works are making first steps towards knowledge engineering, testing the applicability of knowledge based software to industrial automation. The goal is to achieve more intelligent, computer-aided assistance for the personnel and thus to enhance safety, reliability, and maintenance efficiency in large industrial plants. The article presents various examples showing advantages and draw-backs of such systems, and potential applications among others in nuclear or fossil fueled power plants or in electricity supply control systems. (orig./HP) [de

Three AREVA tools for maintenance and outage support

International Nuclear Information System (INIS)

Lumpe, A.

2012-01-01

WlS is a knowledge-based database for the support of nuclear maintenance for components of different types It is productive since 2004 and has been continuously developed according to customer requirements. WIS allows for a centralized management of maintenance information and knowledge, including strategies, scheduling and reporting. WIS is already utilized in national and international NPPs. lts main advantages are: Support of service documentation for plant and service company employees, Support of integration into already existing IT infrastructure, Support of information and knowledge sharing, Easy and intuitive information usage, Savings by using standardized approach.

Reliability-based performance simulation for optimized pavement maintenance

International Nuclear Information System (INIS)

Chou, Jui-Sheng; Le, Thanh-Son

2011-01-01

Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M and R) activities are extremely costly. Unfortunately, the funds available for the M and R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans. - Highlights: →A novel algorithm using multi-objective particle swarm optimization technique. → Evaluation of the cost-reliability tradeoff in a flexible maintenance strategy. → A probabilistic model for regression parameters is employed to assess reliability-based performance. → The proposed approach can help decision makers to optimize roadway maintenance plans.

Reliability-based performance simulation for optimized pavement maintenance

Energy Technology Data Exchange (ETDEWEB)

Chou, Jui-Sheng, E-mail: jschou@mail.ntust.edu.tw [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China); Le, Thanh-Son [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China)

2011-10-15

Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M and R) activities are extremely costly. Unfortunately, the funds available for the M and R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans. - Highlights: > A novel algorithm using multi-objective particle swarm optimization technique. > Evaluation of the cost-reliability tradeoff in a flexible maintenance strategy. > A probabilistic model for regression parameters is employed to assess reliability-based performance. > The proposed approach can help decision makers to optimize roadway maintenance plans.

Knowledge based ranking algorithm for comparative assessment of post-closure care needs of closed landfills.

Science.gov (United States)

Sizirici, Banu; Tansel, Berrin; Kumar, Vivek

2011-06-01

Post-closure care (PCC) activities at landfills include cap maintenance; water quality monitoring; maintenance and monitoring of the gas collection/control system, leachate collection system, groundwater monitoring wells, and surface water management system; and general site maintenance. The objective of this study was to develop an integrated data and knowledge based decision making tool for preliminary estimation of PCC needs at closed landfills. To develop the decision making tool, 11 categories of parameters were identified as critical areas which could affect future PCC needs. Each category was further analyzed by detailed questions which could be answered with limited data and knowledge about the site, its history, location, and site specific characteristics. Depending on the existing knowledge base, a score was assigned to each question (on a scale 1-10, as 1 being the best and 10 being the worst). Each category was also assigned a weight based on its relative importance on the site conditions and PCC needs. The overall landfill score was obtained from the total weighted sum attained. Based on the overall score, landfill conditions could be categorized as critical, acceptable, or good. Critical condition indicates that the landfill may be a threat to the human health and the environment and necessary steps should be taken. Acceptable condition indicates that the landfill is currently stable and the monitoring should be continued. Good condition indicates that the landfill is stable and the monitoring activities can be reduced in the future. The knowledge base algorithm was applied to two case study landfills for preliminary assessment of PCC performance. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hazardous materials on golf courses: Experience and knowledge of golf course superintendents and grounds maintenance workers from seven states

Science.gov (United States)

Arcury-Quandt, Alice E.; Gentry, Amanda L.; Marín, Antonio J.

2011-01-01

Background The golf course industry has a growing Latino work force. Little occupational health research has addressed this work force. This paper examines golf course superintendents’ and Latino grounds maintenance workers’ pesticide knowledge, beliefs, and safety training. In particular, it focuses on knowledge of and adherence to OSHA Right-to-Know regulations. Methods In person, in-depth interviews were conducted with ten golf course superintendents in five states and with sixteen Latino grounds maintenance workers in four states. Results Few superintendents were in compliance with Right-to-Know regulations or did pesticide safety training with all of their workers. Few workers had any pesticide safety knowledge. Most safety training on golf courses was rudimentary and focused on machine safety, and was usually conducted in the off-season or on rainy days, not before workers were assigned tasks. Conclusions More Right-to-Know training is necessary for superintendents and grounds maintenance workers. Culturally and linguistically appropriate Spanish language materials need to be developed or made more widely available to train workers. Better enforcement of safety and training regulations is necessary. PMID:21360723

e-Learning Application for Machine Maintenance Process using Iterative Method in XYZ Company

Science.gov (United States)

Nurunisa, Suaidah; Kurniawati, Amelia; Pramuditya Soesanto, Rayinda; Yunan Kurnia Septo Hediyanto, Umar

2016-02-01

XYZ Company is a company based on manufacturing part for airplane, one of the machine that is categorized as key facility in the company is Millac 5H6P. As a key facility, the machines should be assured to work well and in peak condition, therefore, maintenance process is needed periodically. From the data gathering, it is known that there are lack of competency from the maintenance staff to maintain different type of machine which is not assigned by the supervisor, this indicate that knowledge which possessed by maintenance staff are uneven. The purpose of this research is to create knowledge-based e-learning application as a realization from externalization process in knowledge transfer process to maintain the machine. The application feature are adjusted for maintenance purpose using e-learning framework for maintenance process, the content of the application support multimedia for learning purpose. QFD is used in this research to understand the needs from user. The application is built using moodle with iterative method for software development cycle and UML Diagram. The result from this research is e-learning application as sharing knowledge media for maintenance staff in the company. From the test, it is known that the application make maintenance staff easy to understand the competencies.

Application of condition based maintenance to nuclear power plants

International Nuclear Information System (INIS)

Sonoda, Yukio; Nakano, Tomohito; Shimizu, Shunichi; Iida, Jun; Atomura, Masakazu; Abe, Masahiro

2002-01-01

Device Karte management system which supports application of condition based maintenance to nuclear power plants has been developed. The purpose of this system is to support maintenance personnel in device inspection scheduling based on operating condition monitoring and maintenance histories. There are four functions: field database, degradation estimation, inspection time decision and maintenance planning. The authors have been applying this system to dozens of devices of Onagawa Nuclear Power Station Unit No. 1 for one year. This paper represents the system concept and its application experiences. (author)

Virtual maintenance technology for reactor system based on PPR technology

International Nuclear Information System (INIS)

Wu Yaxiang; Ma Baiyong

2009-01-01

Based on the Product, Process and Resources (PPR) technology, the establishing technology of virtual maintenance environment for the reactor system and the process structure tree for virtual maintenance is studied, and the flow for the maintainability design and simulation for reactor system is put forward. Based on the subsection simulation of maintenance process and layered design of maintenance actions, the leveled structure of the reactor system virtual maintenance task is studied. The relation for the data of product, process and resource is described by Plan Evaluation and Review Technology (PERT) diagram to define the maintenance operation. (authors)

[A preliminary evaluation of mental status and an investigation of occupational health knowledge demand in operating and maintenance personnel in wind power plants].

Science.gov (United States)

Hu, S Q; Zhang, Q; Zhu, X H; Sun, K; Chen, S Z; Liu, A G; Luo, G L; Huang, W

2016-10-20

Objective: To investigate the mental status, level of occupational health knowledge, health behaviors, and occupational health knowledge demand in operating and maintenance personnel in wind power plants, and to provide a basis for formulating protective measures of occupational health for operating and maintenance personnel in wind power plants. Methods: A cluster sampling was performed in regionally representative wind power plants in the wind power industry from May 2014 to June 2015, and the Symptom Checklist-90 (SCL-90) and a self-made evaluation questionnaire were used to investigate the general status, mental health, and occupational health knowledge demand in 160 operating and maintenance workers. Results: Of all respondents, 26.9% had mental health issues. The awareness rate of infectious disease knowledge and preventive measures was 11.9%. Of all workers, 96.5% wanted to know the occupational hazard factors in the workplace, and 96.3% wanted to get the knowledge of the prevention of related diseases. Conclusion: Mental health issues in operating and maintenance personnel in wind power plants cannot be neglected and there is a high demand for occupational health services and related knowledge. Comprehensive intervention measures for health promotion in the workplace should be adopted to improve working environment, enhance individual mental health education, increase the level of occupational health management, and protect the health of workers.

Distributed Knowledge Management in Extranets

DEFF Research Database (Denmark)

Pedersen, Mogens Kühn; Larsen, Michael Holm

1999-01-01

Knowledge management exchange schemes based on symmetric incentives are rarely found in the literature. The distributed knowledge model relies upon a double loop knowledge conversion decision support system with symmetric incentives in an extranet. The model merges specific knowledge with knowledge...... chains and networks like replacement, maintenance and services industries....

Maintenance for the Millennium: Another Approach

International Nuclear Information System (INIS)

Sculthorpe, Barruy R.

2002-01-01

Nuclear units nationwide are struggling to increase plant reliability and availability while at the same time reduce their operating and maintenance costs. Some very costly investments have been made in programs such as Reliability Centered Maintenance [RCM]. Florida Power and Light's approach at the St. Lucie Nuclear Plant has taken a slightly different approach. Building on our knowledge of the RCM process and an already existing 'World Class' Predictive Maintenance Program, a 'Condition-Based' Maintenance Program that takes advantage of the RCM philosophy and our toolbox full of advanced and highly successful predictive maintenance technologies. These tools currently consist of vibration analysis, lubricant analysis (both physical property and wear metals analysis, thermographic analysis, motor current signature analysis, tribology and process parameter trending. All employed with the intent to evaluate a machines health. This machine health check allows the forecasting of future preventative maintenance [PM's] tasks and the revision of existing PM's to maximize machine performance and eliminate 'no-value-added' maintenance activities/costs. Within the last year, the Condition-Based Maintenance Program has produced a cost saving of approximately $1.5 million dollars. As the program matures, these cost savings will accumulate well into the millennium. (authors)

Risk-Based Operation and Maintenance of Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Sønderkær

For offshore wind turbines, maintenance costs are substantial due to a large number of component failures. In addition to the repair costs, equipment costs and lost production costs are large due to limited accessibility to the turbines. In order to reduce the costs, preventive methods can be used......, but presently maintenance is not planned using advanced methods taking all available information into account in a consistent manner. Maintenance decisions can be made based on risk-based methods, where the total expected life cycle costs are minimized. Methods have been developed for assessing the corrective...... maintenance costs, and many studies have also been published for preventive maintenance. However, an important part is the modeling of the relationship between maintenance and reliability, which is typically not modeled in a consistent way. Therefore, the methods cannot be used directly for optimal...

Knowledge and the Maintenance of Entrepreneurial Capability

OpenAIRE

Luc Tardieu

2003-01-01

This paper intends to bridge the austrian theory of entrepreneurship and the recent developments of the theory of the firm, namely the Knowledge Based Approach. The KBA and the theory of entrepreneurship share a common focus on knowledge and coordination. It is argued herein that by examining the cognitive foundations of entrepreneurship it is possible to connect the KBA and the theory of entrepreneurship. Entrepreneurship is by essence a matter of opportunities. An entrepreneurial opportunit...

Space nuclear reactor system diagnosis: Knowledge-based approach

International Nuclear Information System (INIS)

Ting, Y.T.D.

1990-01-01

SP-100 space nuclear reactor system development is a joint effort by the Department of Energy, the Department of Defense and the National Aeronautics and Space Administration. The system is designed to operate in isolation for many years, and is possibly subject to little or no remote maintenance. This dissertation proposes a knowledge based diagnostic system which, in principle, can diagnose the faults which can either cause reactor shutdown or lead to another serious problem. This framework in general can be applied to the fully specified system if detailed design information becomes available. The set of faults considered herein is identified based on heuristic knowledge about the system operation. The suitable approach to diagnostic problem solving is proposed after investigating the most prevalent methodologies in Artificial Intelligence as well as the causal analysis of the system. Deep causal knowledge modeling based on digraph, fault-tree or logic flowgraph methodology would present a need for some knowledge representation to handle the time dependent system behavior. A proposed qualitative temporal knowledge modeling methodology, using rules with specified time delay among the process variables, has been proposed and is used to develop the diagnostic sufficient rule set. The rule set has been modified by using a time zone approach to have a robust system design. The sufficient rule set is transformed to a sufficient and necessary one by searching the whole knowledge base. Qualitative data analysis is proposed in analyzing the measured data if in a real time situation. An expert system shell - Intelligence Compiler is used to develop the prototype system. Frames are used for the process variables. Forward chaining rules are used in monitoring and backward chaining rules are used in diagnosis

Risk-Based Operation and Maintenance of Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2009-01-01

For offshore wind turbines costs to operation and maintenance are substantial. This paper describes a risk-based lifecycle approach for optimal planning of operation and maintenance. The approach is based on pre-posterior Bayesian decision theory. Deterioration mechanisms such as fatigue, corrosion...

Risk-based Operation and Maintenance for Offshore Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Nielsen, Jannie Jessen

2011-01-01

For offshore wind turbines, costs to Operation and Maintenance (OM) are substantial, and can be expected to increase when wind farms are placed at deeper water depths and in more harsh environments. Traditional strategies for OM include corrective and preventive (scheduled and condition...... statistics and costs of the different operations. The different OM strategies are described and compared in an illustrative example with focus on which types of information that are needed. Special focus is on comparison between risk-based maintenance strategies and the conventional maintenance planning...... and are often the driving mechanisms for failures / faults that need maintenance. Observations of the degree of damage can increase the reliability of predictions and decrease the costs of OM if integrated in a risk-based framework theoretically based on pre-posterior Bayesian decision theory. The mathematical...

Knowledge base mechanisms

Energy Technology Data Exchange (ETDEWEB)

Suwa, M; Furukawa, K; Makinouchi, A; Mizoguchi, T; Mizoguchi, F; Yamasaki, H

1982-01-01

One of the principal goals of the Fifth Generation Computer System Project for the coming decade is to develop a methodology for building knowledge information processing systems which will provide people with intelligent agents. The key notion of the fifth generation computer system is knowledge used for problem solving. In this paper the authors describe the plan of Randd on knowledge base mechanisms. A knowledge representation system is to be designed to support knowledge acquisition for the knowledge information processing systems. The system will include a knowledge representation language, a knowledge base editor and a debugger. It is also expected to perform as a kind of meta-inference system. In order to develop the large scale knowledge base systems, a knowledge base mechanism based on the relational model is to be studied in the earlier stage of the project. Distributed problem solving is also one of the main issues of the project. 19 references.

Maintenance Decision Making based on different types of data fusion

OpenAIRE

Galar, D.; Gustafson, A.; Tormos Martínez, Bernardo Vicente; Berges, Luis

2012-01-01

[EN] Over the last decade, system integration is applied more as it allows organizations to streamline business processes. A recent development in the asset engineering management is to leverage the investment already made in process control systems. This allows the operations, maintenance, and process control teams to monitor and determine new alarm level based on the physical condition data of the critical machines. Condition-based maintenance (CBM) is a maintenance philosophy base...

Optimizing block-based maintenance under random machine usage

NARCIS (Netherlands)

de Jonge, Bram; Jakobsons, Edgars

Existing studies on maintenance optimization generally assume that machines are either used continuously, or that times until failure do not depend on the actual usage. In practice, however, these assumptions are often not realistic. In this paper, we consider block-based maintenance optimization

The-Abstraction-Hierarchy-based Mobile PC Display Design for NPP Maintenance

International Nuclear Information System (INIS)

Kim, In; Kim, Bo Gyung; Seong, Poong Hyun; Ha, Jun Su

2010-01-01

Recently, the importance of effective maintenance in nuclear power plants (NPPs) has been emphasized and research into effective maintenance by adopting mobile maintenance aids (MMAs) have been attempted. For improved and effective use of an MMA display design method based on abstraction hierarchy (AH) is proposed and its design considerations are discussed in this study. Six levels of abstraction hierarchy are proposed in this paper to classify the maintenance information. By classifying and organizing maintenance information using AH, maintenance information can be used effectively by users with either high or low levels of expertise. When information classification has been finished, the information for MMA design is selected and designed. With the considerations of MMA design analysis and guidelines, AH-based MMA is designed for the maintenance tasks. An experiment is conducted using the AH-based MMA in order to estimate the effectiveness of the proposed method for the maintenance tasks and to identify design considerations to enhance the proposed MMAs. The result indicated that an AH-based manual was more effective than a conventional manual in terms of task completion time and number of errors. The workload for the AH-based manual was estimated less than the conventional manual for subjects with low level of expertise. As the level of expertise increases, subjects tended to follow more abstract information while the number of navigations decreased. It is believed that when mobile devices become pervasive in NPP maintenance fields, AH-model applied MMAs can be used as an effective maintenance supporting tool

Risk based maintenance: Resource requirements and organizational challenges

International Nuclear Information System (INIS)

Weerakkody, S.D.

2000-01-01

10CFR50.65 'Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants' required licensees to monitor the performance or condition of structures, systems, or components (SSCs) against licensee established goals, in a manner sufficient to provide reasonable assurance that such SSCs are capable of fulfilling their intended functions. The goals were required to be commensurate with safety significance and operating experience. Northeast Utilities relied upon PRAs to implement 10CFR50.65, which is also referred to as the 'Maintenance Rule'. The Maintenance Rule changed some aspects of maintenance of structures, systems, and components (SSC) at nuclear power plants. One objective of the rule was to focus the maintenance resources based on risk significance of components. This paper will discuss the organizational challenges and resource requirements associated with implementation of the Maintenance Rule at nuclear facilities that are supported by the Northeast Utilities Services Company (NUSCo). The paper will discuss (a) how these challenges were addressed, (b) the resources required for ongoing efforts to support the Maintenance Rule, and (c) several key safety benefits derived from the implementation of the Maintenance Rule. (author)

Integrated maintenance management model in the printing industry

Directory of Open Access Journals (Sweden)

Csaba Horváth

2010-09-01

Full Text Available Rapid technological and economic changes are setting radically new task for maintenance divisions of printingworks. In this dissertation the author provides a summary on the possible approaches for the adoption to the newrequirements. He formulates his situation analysis based on an exhaustive questionnaire survey, and points out thecurrents of changes and challenges caused by the expected developments in the maintenance field of the printingindustry.Based on the possible answers on these challenges, the Author has compiled a - yet missing - maintenance managementmodel that encompasses the maintenance specialties of the industry, as well as the professional heritage andthe latest scientific accomplishments in the discipline of maintenance.The model is based on the widely accepted quality focused maintenance approach, that is supplemented by theAuthor with four new aspects - 1 reliability-focused culture, 2 quality management system, 3 employment ofexternal service provides, 4 maintenance characteristics specific to printing machinery - determining their effectsand integrating them into one single system.In order to construct the model, the Author develops specific solutions that can be seen as own scientific achievementson the specification of maintenance characteristics of printing machinery; on the efficiency improving applicationsof quality management systems, modern knowledge management and reliability focused corporate culture;and on the implementation of a maintenance information system.

A development of maintenance educational support method by using navigation method Pt. 4. A development of a paper prototype system for the RHR pump maintenance educational support

International Nuclear Information System (INIS)

Yoshino, Kenji; Hirotsu, Yuko; Fujimoto, Junzo; Tsumura, Joji

2004-01-01

This research establishes the new maintenance educational support prototype system for aiming at organization as Trinity (a supervision person, a construction person in charge, a work person in charge, and group length), and improvement in human reliability for the purpose of aiming at before hand prevention of a systematic error, human error, and the accident and a trouble. (1) This maintenance educational support: system made educational start to the educational end the structure navigated exactly, carrying out the exchange with a data base along with the road map which divided action (act) of the work process and worker concerning RHR pump maintenance work for a participant etc. by class. (2) First, according to a participant's attribute, this educational support system performs educational support (a question and reply) concerning an organization and organization, and judges knowledge and a nature type based on the result. Furthermore, educational support (a question and reply) concerning maintenance work is performed, and a knowledge level is judged based on the result. And it considered as the structure which performs the comprehensive judgment about an organization, organization, and the educational effect concerning maintenance work at the last. (3) The judgment pattern of the knowledge and nature after the educational support end concerning a participant's organization and organization was made into four kinds which consist of (1) organization priority and duty A type, (2) organization priority and an adaptable type, (3) individual priority and an adaptable type, and (4) individual priority and a duty priority type. (4) The judgment pattern of the knowledge level after the educational support end concerning maintenance work of a participant was used as three kinds of evaluation axes, schedule management, apparatus reliability capability, and human-being reliability. (author)

Clustering condition-based maintenance for a multi-unit system with aperiodic inspections

NARCIS (Netherlands)

Olde Keizer, Minou C.A.; Teunter, Ruud H.; Podofillini, Luca; Sudret, Bruno; Stojadinović, Božidar; Zio, Enrico; Kröger, Wolfgang

2015-01-01

Condition-Based Maintenance (CBM) is a predictive maintenance strategy, which bases the maintenance scheduling on condition measurements of the components. In this paper, we continue work on the CBM optimization approach proposed by Castanier, B., A. Grall & C. Bérenguer (2005). A condition-based

The International Coal Statistics Data Base program maintenance guide

International Nuclear Information System (INIS)

1991-06-01

The International Coal Statistics Data Base (ICSD) is a microcomputer-based system which contains information related to international coal trade. This includes coal production, consumption, imports and exports information. The ICSD is a secondary data base, meaning that information contained therein is derived entirely from other primary sources. It uses dBase III+ and Lotus 1-2-3 to locate, report and display data. The system is used for analysis in preparing the Annual Prospects for World Coal Trade (DOE/EIA-0363) publication. The ICSD system is menu driven and also permits the user who is familiar with dBase and Lotus operations to leave the menu structure to perform independent queries. Documentation for the ICSD consists of three manuals -- the User's Guide, the Operations Manual, and the Program Maintenance Manual. This Program Maintenance Manual provides the information necessary to maintain and update the ICSD system. Two major types of program maintenance documentation are presented in this manual. The first is the source code for the dBase III+ routines and related non-dBase programs used in operating the ICSD. The second is listings of the major component database field structures. A third important consideration for dBase programming, the structure of index files, is presented in the listing of source code for the index maintenance program. 1 fig

Long-Term Surveillance and Maintenance Records: Maintaining Access to the Knowledge - 13122

International Nuclear Information System (INIS)

Montgomery, John; Gueretta, Jeanie; McKinney, Ruth; Anglim, Cliff

2013-01-01

The U.S. Department of Energy (DOE) Office of Legacy Management (LM) is an integral part of DOE's strategy to ensure that legacy liabilities of former nuclear weapons production sites are properly managed following the completion of environmental cleanup activities. In the area of environmental legacy management, records management is crucial to the protection of health, environmental, and legal interests of the Department and the public. LM is responsible for maintaining long-term surveillance and maintenance (LTS and M) records in performance of its mission. Maintaining access to the knowledge contained in these record collections is one of LM's primary responsibilities. To fulfill this responsibility, LM established a consolidated records management facility, the LM Business Center (LMBC), to house physical media records and electronic records. A new electronic record keeping system (ERKS) was needed to replace an obsolete system while helping to ensure LM is able to meet ongoing responsibilities to maintain access to knowledge and control the life cycle management of records. (authors)

Operation and maintenance requirements of system design bases

International Nuclear Information System (INIS)

Banerjee, A.K.; Hanley, N.E.

1989-01-01

All system designs make assumptions about system operation testing, inspection, and maintenance. Existing industry codes and standards explicitly address design requirements of new systems, while issues related to system and plant reliability, life, design margins, effects of service conditions, operation, maintenance, etc., usually are implicit. However, system/component design documents of existing power plants often address the code requirements without considering the operation, maintenance, inspection, and testing (OMIT) requirements. The nuclear industry is expending major efforts at most nuclear power plants to reassemble and/or reconstitute system design bases. Stone ampersand Webster Engineering Corporation (SWEC) recently addressed the OMIT requirements of system/component design as an integral part of a utility's preventive maintenance program. For each component, SWEC reviewed vendor recommendations, NPRDS data/industry experience, the existing maintenance program, component service conditions, and actual plant experience. A maintenance program that considers component service conditions and plant experience ensures a connection between maintenance and design basis. Root cause analysis of failure and engineering evaluation of service condition are part of the program. System/component OMIT requirements also are compared against system design, service condition, degradation mechanism, etc., through system/component life-cycle evaluation

The arhitecture of the human resources in management based on knowledge and the impact on reduncing unemployment

Directory of Open Access Journals (Sweden)

Amalia Venera Todoruţ

2011-03-01

Full Text Available In this working paper I proposed to address/aproach issues of relationship and interdependence of human resources and management based on knowledges. I presented during the paper the new type of human resource management and new challenges which are noted in the current economic conjuncture and their influences on human resource management. We have also shown which is the new type of organizational culture and its impact on management based on knowledge. I focused also on the modalities how influence the management of human resources the management based on knowledge materialized in: the organization employee involvement, strong motivation and retention of employees in the firm based on knowledge, connection of management based on knowledges and the human resource management on the firm strategy, development of employees capacity and the intellectual capital, the creation and maintenance of learning practices widely used in business.

Human factor analysis and preventive countermeasures of maintenance in nuclear power plant

International Nuclear Information System (INIS)

Zhang Li; Hu Chao

2008-01-01

Based on the human error analysis theory and the characteristics of maintenance in a nuclear power plant, human factors of maintenance in NPP are divided into three different areas: human, technology, and organization, in which human refers to the individual factors, mainly including psychological quality, physiological characteristic, state of health, knowledge, skill level, and interpersonal relationship. Technology includes the maintenance technology, maintenance strategy, maintenance tool, maintenance interface, maintenance regulation, and work environment. Organization includes task arrangement, information communication, training, personnel external environment, team construction, and leadership. The analysis also reveals that the organization factors, which can indirectly influence personnel performance, are the primary initiators of human error. Based on these, some countermeasures are brought forward in order to reduce human errors. (authors)

TRIZ method application for improving the special vehicles maintenance

OpenAIRE

Petrović Saša; Lozanović-Šajić Jasmina; Knežević Tijana; Pavlović Jovan; Ivanov Goran

2014-01-01

TRIZ methodology provides an opportunity for improving the classical engineering approach based on personal knowledge and experience. This paper presents the application of TRIZ methods for improving vehicle maintenance where special equipment is installed. A specific problem is the maintenance of the periscopes with heating system. Protective glass panels with heating system are rectangular glass elements. Their purpose is to perform mechanical protection ...

Risk-Based Operation and Maintenance of Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Sønderkær

to oil and gas structures. In addition, condition monitoring systems are often available, and the information should be taken into account when making decisions. In this thesis, methods for risk-based maintenance planning using Bayesian methods are investigated, with the aim of making optimal decisions......, but presently maintenance is not planned using advanced methods taking all available information into account in a consistent manner. Maintenance decisions can be made based on risk-based methods, where the total expected life cycle costs are minimized. Methods have been developed for assessing the corrective...... considering all available information. First, a theoretical damage model is formulated, the model is then updated using condition monitoring data, and the updated model is used as basis for risk-based decision making. Several approaches for solving the decision problems have been considered: various types...

An assessment of maintainability of elevator system to improve facilities management knowledge-base

Science.gov (United States)

Siti, N. A.; Asmone, A. S.; Chew, M. Y. L.

2018-02-01

Elevator system is a highly specialized machinery that requires technicians that have a wider array of knowledge in maintaining the system to be safe and reliable. While attaining reliable data of elevator malfunction become challenges, this study has filled the gap by gathering the management-maintenance issues and operational defects of elevator system. Forty-three types of operation defects were found and the consequence defects and their possible causes of occurrences were discussed. To respond to the prime challenges of maintaining elevator system provided by the industry players’ perspective, a theoretical framework is established as a recommendation to improve knowledge base of defects in elevator system which comprises good practices, and solutions to rectify each defects found. Hence, this research paper has theoretically improved the knowledge base of maintainability of elevator system and provide meaningful guidelines in practical senses to the industry professionals.

Role of Knowledge Based Communities in Knowledge Process

Directory of Open Access Journals (Sweden)

Sebastian Ion CEPTUREANU

2015-12-01

Full Text Available In the new economy, knowledge is an essential component of economic and social systems. The organizational focus has to be on building knowledge-based management, development of human resource and building intellectual capital capabilities. Knowledge-based management is defined, at company level, by economic processes that emphasize creation, selling, buying, learning, storing, developing, sharing and protection of knowledge as a decisive condition for profit and long-term sustainability of the company. Hence, knowledge is, concurently, according to a majoritiy of specialists, raw material, capital, product and an essential input. Knowledge-based communities are one of the main constituent elements of a framework for knowledge based management. These are peer networks consisting of practitioners within an organization, supporting each other to perform better through the exchange and sharing of knowledge. Some large companies have contributed or supported the establishment of numerous communities of practice, some of which may have several thousand members. They operate in different ways, are of different sizes, have different areas of interest and addresses knowledge at different levels of its maturity. This article examines the role of knowledge-based communities from the perspective of knowledge based management, given that the arrangements for organizational learning, creating, sharing, use of knowledge within organizations become more heterogeneous and take forms more difficult to predict by managers and specialists.

Ontology-based configuration of problem-solving methods and generation of knowledge-acquisition tools: application of PROTEGE-II to protocol-based decision support.

Science.gov (United States)

Tu, S W; Eriksson, H; Gennari, J H; Shahar, Y; Musen, M A

1995-06-01

PROTEGE-II is a suite of tools and a methodology for building knowledge-based systems and domain-specific knowledge-acquisition tools. In this paper, we show how PROTEGE-II can be applied to the task of providing protocol-based decision support in the domain of treating HIV-infected patients. To apply PROTEGE-II, (1) we construct a decomposable problem-solving method called episodic skeletal-plan refinement, (2) we build an application ontology that consists of the terms and relations in the domain, and of method-specific distinctions not already captured in the domain terms, and (3) we specify mapping relations that link terms from the application ontology to the domain-independent terms used in the problem-solving method. From the application ontology, we automatically generate a domain-specific knowledge-acquisition tool that is custom-tailored for the application. The knowledge-acquisition tool is used for the creation and maintenance of domain knowledge used by the problem-solving method. The general goal of the PROTEGE-II approach is to produce systems and components that are reusable and easily maintained. This is the rationale for constructing ontologies and problem-solving methods that can be composed from a set of smaller-grained methods and mechanisms. This is also why we tightly couple the knowledge-acquisition tools to the application ontology that specifies the domain terms used in the problem-solving systems. Although our evaluation is still preliminary, for the application task of providing protocol-based decision support, we show that these goals of reusability and easy maintenance can be achieved. We discuss design decisions and the tradeoffs that have to be made in the development of the system.

Development of design system of manipulator for fusion reactor maintenance

International Nuclear Information System (INIS)

Ida, Toshio; Niikura, Setsuo; Ishiguro, Akiko; Yamada, Masao; Matsuoka, Fushiki

1989-01-01

A program which supports designers of a manipulator for in-vessel maintenance of a fusion reactor has been developed. The main purpose of this program is to provide the designer with a promising manipulator specification by furnishing useful information. It combines a technique of knowledge engineering with numerical solutions. This program consists of three parts: The first part is to generate candidates for the manipulator using a knowledge base; the second is to evaluate both static and dynamic properties of each candidate through numerical simulation of the maintenance task; and the third is to select the candidates having better performance and feasibility on the basis of the simulation data and knowledge base. The feasibility of the method used in this program is confirmed by the preliminary application. This application also emphasizes the importance of the knowledge base for the candidate generation and selection. Although the degree of freedom of the manipulator is restricted to less than 7 degrees in this study, further development of the capability of manipulator simulation (seven or more degrees of freedom) will enhance the effectiveness of this program. (orig.)

Preventive maintenance: optimization of time - based discard decisions at the bruce nuclear generating station

International Nuclear Information System (INIS)

Doyle, E.K.; Jardine, A.K.S.

2001-01-01

The use of various maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems. As previously reported at ICONE 6 in New Orleans, 1996, several innovative practices reduced Reliability Centered Maintenance costs while maintaining the accuracy of the analysis. The optimization strategy has undergone further evolution and at the present an Integrated Maintenance Program (IMP) is in place where an Expert Panel consisting of all players/experts proceed through each system in a disciplined fashion and reach agreement on all items under a rigorous time frame. It is well known that there are essentially 3 maintenance based actions that can flow from a Maintenance Optimization Analysis: condition based maintenance, time based maintenance and time based discard. The present effort deals with time based discard decisions. Maintenance data from the Remote On-Power Fuel Changing System was used. (author)

A condition-based maintenance policy for stochastically deteriorating systems

International Nuclear Information System (INIS)

Grall, A.; Berenguer, C.; Dieulle, L.

2002-01-01

We focus on the analytical modeling of a condition-based inspection/replacement policy for a stochastically and continuously deteriorating single-unit system. We consider both the replacement threshold and the inspection schedule as decision variables for this maintenance problem and we propose to implement the maintenance policy using a multi-level control-limit rule. In order to assess the performance of the proposed maintenance policy and to minimize the long run expected maintenance cost per unit time, a mathematical model for the maintained system cost is derived, supported by the existence of a stationary law for the maintained system state. Numerical experiments illustrate the performance of the proposed policy and confirm that the maintenance cost rate on an infinite horizon can be minimized by a joint optimization of the maintenance structure thresholds, or equivalently by a joint optimization of a system replacement threshold and the aperiodic inspection schedule

Towards Agile Ontology Maintenance

Science.gov (United States)

Luczak-Rösch, Markus

Ontologies are an appropriate means to represent knowledge on the Web. Research on ontology engineering reached practices for an integrative lifecycle support. However, a broader success of ontologies in Web-based information systems remains unreached while the more lightweight semantic approaches are rather successful. We assume, paired with the emerging trend of services and microservices on the Web, new dynamic scenarios gain momentum in which a shared knowledge base is made available to several dynamically changing services with disparate requirements. Our work envisions a step towards such a dynamic scenario in which an ontology adapts to the requirements of the accessing services and applications as well as the user's needs in an agile way and reduces the experts' involvement in ontology maintenance processes.

Maintenance Decision Based on Data Fusion of Aero Engines

Directory of Open Access Journals (Sweden)

Huawei Wang

2013-01-01

Full Text Available Maintenance has gained a great importance as a support function for ensuring aero engine reliability and availability. Cost-effectiveness and risk control are two basic criteria for accurate maintenance. Given that aero engines have much condition monitoring data, this paper presents a new condition-based maintenance decision system that employs data fusion for improving accuracy of reliability evaluation. Bayesian linear model has been applied, so that the performance degradation evaluation of aero engines could be realized. A reliability evaluation model has been presented based on gamma process, which achieves the accurate evaluation by information fusion. In reliability evaluation model, the shape parameter is estimated by the performance degradation evaluation result, and the scale parameter is estimated by failure, inspection, and repair information. What is more, with such reliability evaluation as input variables and by using particle swarm optimization (PSO, a stochastic optimization of maintenance decision for aircraft engines has been presented, in which the effectiveness and the accuracy are demonstrated by a numerical example.

Long-Term Surveillance and Maintenance Records: Maintaining Access to the Knowledge - 13122

Energy Technology Data Exchange (ETDEWEB)

Montgomery, John; Gueretta, Jeanie [U.S. Department of Energy Office of Legacy Management, 99 Research Park Road Morgantown, WV 26505 (United States); McKinney, Ruth; Anglim, Cliff [Source One Management, Inc. (United States)

2013-07-01

The U.S. Department of Energy (DOE) Office of Legacy Management (LM) is an integral part of DOE's strategy to ensure that legacy liabilities of former nuclear weapons production sites are properly managed following the completion of environmental cleanup activities. In the area of environmental legacy management, records management is crucial to the protection of health, environmental, and legal interests of the Department and the public. LM is responsible for maintaining long-term surveillance and maintenance (LTS and M) records in performance of its mission. Maintaining access to the knowledge contained in these record collections is one of LM's primary responsibilities. To fulfill this responsibility, LM established a consolidated records management facility, the LM Business Center (LMBC), to house physical media records and electronic records. A new electronic record keeping system (ERKS) was needed to replace an obsolete system while helping to ensure LM is able to meet ongoing responsibilities to maintain access to knowledge and control the life cycle management of records. (authors)

Aging management: Control of the knowledge data base

Energy Technology Data Exchange (ETDEWEB)

Schoeckle, F., E-mail: fs@amtec.de [Amtec Services, Hoher Steg 13, 74348 Laufen (Germany); Rothenhoefer, H. [Amtec Services, Hoher Steg 13, 74348 Laufen (Germany); Koenig, G. [EnBW Kernkraft, Kernkraftwerk Neckarwestheim, 74380 Neckarwestheim (Germany)

2014-04-01

Aging management is part of the safety management system in NPP Neckarwestheim, Germany. The central goal of aging management is to increase knowledge about aging mechanisms acting on systems, structures and components (SSC), steadily. Comprehensive knowledge is a pre-requisite to guard against aging related systematic failures. To increase knowledge it is necessary to gather and evaluate data of different departments, systematically. While a nuclear power plant is in service numerous events may occur which are related to aging and may have an influence on the quality of SSC. Relevant events may be malfunction, maintenance results, operational experience, results of surveillance or events in other utilities. It is important to evaluate these events concerning the aspect of aging, regularly, and to decide which measures are required to prevent similar unexpected events in the future. In some cases the new experience has to be assigned to comparable SSC. These evaluations and the necessary measures as well as the tracking of their effectiveness are performed by an aging management team that meets every 3 months. The resulting knowledge data base (aging management data base) supports the application of the PDCA cycle and provides an overview and fast access to all quality documents related to each SSC including surveillance measures and results. It simplifies the generation of annual status reports which demonstrate the efficiency of aging management. Finally, the procedure can be extended to SSC which are important for the availability of the plant and thus take a step forward from aging management to plant life management.

Model based decision support for planning of road maintenance

NARCIS (Netherlands)

van Harten, Aart; Worm, J.M.; Worm, J.M.

1996-01-01

In this article we describe a Decision Support Model, based on Operational Research methods, for the multi-period planning of maintenance of bituminous pavements. This model is a tool for the road manager to assist in generating an optimal maintenance plan for a road. Optimal means: minimising the

Maintenance of KBS’s by domain experts the holy grail in practice

NARCIS (Netherlands)

Bultman, Arne; Kuipers, Joris; Van Harmelen, Frank

2000-01-01

Enabling a domain expert to maintain his own knowledge in a Knowledge Based System has long been an ideal for the Knowledge Engineering community. In this paper we report on our experience with trying to achieve this ideal in a practical setting, by building a maintenance tool for an existing KBS.

Knowledge-based public health situation awareness

Science.gov (United States)

Mirhaji, Parsa; Zhang, Jiajie; Srinivasan, Arunkumar; Richesson, Rachel L.; Smith, Jack W.

2004-09-01

There have been numerous efforts to create comprehensive databases from multiple sources to monitor the dynamics of public health and most specifically to detect the potential threats of bioterrorism before widespread dissemination. But there are not many evidences for the assertion that these systems are timely and dependable, or can reliably identify man made from natural incident. One must evaluate the value of so called 'syndromic surveillance systems' along with the costs involved in design, development, implementation and maintenance of such systems and the costs involved in investigation of the inevitable false alarms1. In this article we will introduce a new perspective to the problem domain with a shift in paradigm from 'surveillance' toward 'awareness'. As we conceptualize a rather different approach to tackle the problem, we will introduce a different methodology in application of information science, computer science, cognitive science and human-computer interaction concepts in design and development of so called 'public health situation awareness systems'. We will share some of our design and implementation concepts for the prototype system that is under development in the Center for Biosecurity and Public Health Informatics Research, in the University of Texas Health Science Center at Houston. The system is based on a knowledgebase containing ontologies with different layers of abstraction, from multiple domains, that provide the context for information integration, knowledge discovery, interactive data mining, information visualization, information sharing and communications. The modular design of the knowledgebase and its knowledge representation formalism enables incremental evolution of the system from a partial system to a comprehensive knowledgebase of 'public health situation awareness' as it acquires new knowledge through interactions with domain experts or automatic discovery of new knowledge.

KNOWLEDGE SOCIETY, GENERAL FRAMEWORK FOR KNOWLEDGE BASED ECONOMY

Directory of Open Access Journals (Sweden)

Dragos CRISTEA

2011-03-01

Full Text Available This paper tries to present the existent relation between knowledge society and knowledge based economy. We will identify the main pillars of knowledge society and present their importance for the development of knowledge societies. Further, we will present two perspectives over knowledge societies, respectively science and learning perspectives, that directly affects knowledge based economies. At the end, we will conclude by identifying some important questions that must be answered regarding this new social paradigm.

Optimal, Risk-based Operation and Maintenance Planning for Offshore Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2008-01-01

For offshore wind turbines costs to operation and maintenance are substantial. This paper describes a risk-based life-cycle approach for optimal planning of operation and maintenance. The approach is based on pre-posterior Bayesian decision theory. Deterioration mechanisms such as fatigue...

Knowledge-based utility

International Nuclear Information System (INIS)

Chwalowski, M.

1997-01-01

This presentation provides industry examples of successful marketing practices by companies facing deregulation and competition. The common thread through the examples is that long term survival of today's utility structure is dependent on the strategic role of knowledge. As opposed to regulated monopolies which usually own huge physical assets and have very little intelligence about their customers, unregulated enterprises tend to be knowledge-based, characterized by higher market value than book value. A knowledge-based enterprise gathers data, creates information and develops knowledge by leveraging it as a competitive weapon. It institutionalizes human knowledge as a corporate asset for use over and over again by the use of databases, computer networks, patents, billing, collection and customer services (BCCS), branded interfaces and management capabilities. Activities to become knowledge-based such as replacing inventory/fixed assets with information about material usage to reduce expenditure and achieve more efficient operations, and by focusing on integration and value-adding delivery capabilities, were reviewed

Present status of the Nuclear Maintenance Training Center

International Nuclear Information System (INIS)

Kotani, Fumio

1995-01-01

The education and training to keep and improve the knowledge and skills of the maintenance personnel and to hand down the skills undoubtedly play important roles in safe operation and increased reliability to a nuclear power station. The Nuclear Maintenance Training Center (hereafter called the Center) provides a variety of education and training curriculums based on the levels and abilities of the trainees. The Center aims to enhance the personnel's maintenance technique by offering the curriculums on maintenance basic education for operators and supporting education and training for the personnel of contractors. The Center has two main features: first, it has the actual components or the equipment similar to the actual components which will enable the practical training; second, we regard the past troubles as valuable experiences and, therefore, focuses on the education to prevent recurrence of troubles by teaching the trainees the meaning and necessity of the training they take. For eleven years since the establishment of the Center, it has been utilized by the total number of about 60,000 people. As for the tasks in the future, the Center is expected to vitalize itself to give attractive education and training and become more actively involved in development of the maintenance personnel with the adequate knowledge and skills. (author)

Performance-based maintenance of gas turbines for reliable control of degraded power systems

Science.gov (United States)

Mo, Huadong; Sansavini, Giovanni; Xie, Min

2018-03-01

Maintenance actions are necessary for ensuring proper operations of control systems under component degradation. However, current condition-based maintenance (CBM) models based on component health indices are not suitable for degraded control systems. Indeed, failures of control systems are only determined by the controller outputs, and the feedback mechanism compensates the control performance loss caused by the component deterioration. Thus, control systems may still operate normally even if the component health indices exceed failure thresholds. This work investigates the CBM model of control systems and employs the reduced control performance as a direct degradation measure for deciding maintenance activities. The reduced control performance depends on the underlying component degradation modelled as a Wiener process and the feedback mechanism. To this aim, the controller features are quantified by developing a dynamic and stochastic control block diagram-based simulation model, consisting of the degraded components and the control mechanism. At each inspection, the system receives a maintenance action if the control performance deterioration exceeds its preventive-maintenance or failure thresholds. Inspired by realistic cases, the component degradation model considers random start time and unit-to-unit variability. The cost analysis of maintenance model is conducted via Monte Carlo simulation. Optimal maintenance strategies are investigated to minimize the expected maintenance costs, which is a direct consequence of the control performance. The proposed framework is able to design preventive maintenance actions on a gas power plant, to ensuring required load frequency control performance against a sudden load increase. The optimization results identify the trade-off between system downtime and maintenance costs as a function of preventive maintenance thresholds and inspection frequency. Finally, the control performance-based maintenance model can reduce

Virk: An Active Learning-based System for Bootstrapping Knowledge Base Development in the Neurosciences

Directory of Open Access Journals (Sweden)

Kyle H. Ambert

2013-12-01

Full Text Available The frequency and volume of newly-published scientific literature is quickly making manual maintenance of publicly-available databases of primary data unrealistic and costly. Although machine learning can be useful for developing automated approaches to identifying scientific publications containing relevant information for a database, developing such tools necessitates manually annotating an unrealistic number of documents. One approach to this problem, active learning, builds classification models by iteratively identifying documents that provide the most information to a classifier. Although this approach has been shown to be effective for related problems, in the context of scientific databases curation, it falls short. We present Virk, an active learning system that, while being trained, simultaneously learns a classification model and identifies documents having information of interest for a knowledge base. Our approach uses a support vector machine classifier with input features derived from neuroscience-related publications from the primary literature. Using our approach, we were able to increase the size of the Neuron Registry, a knowledge base of neuron-related information, by a factor of 90%, a knowledge base of neuron-related information, in 3 months. Using standard biocuration methods, it would have taken between 1-2 years to make the same number of contributions to the Neuron Registry. Here, we describe the system pipeline in detail, and evaluate its performance against other approaches to sampling in active learning.

Statistical Learning Framework with Adaptive Retraining for Condition-Based Maintenance

International Nuclear Information System (INIS)

An, Sang Ha; Chang, Soon Heung; Heo, Gyun Young; Seo, Ho Joon; Kim, Su Young

2009-01-01

As systems become more complex and more critical in our daily lives, the need for the maintenance based on the reliable monitoring and diagnosis has become more apparent. However, in reality, the general opinion has been that 'maintenance is a necessary evil' or 'nothing can be done to improve maintenance costs'. Perhaps these were true statements twenty years ago when many of the diagnostic technologies were not fully developed. The developments of microprocessor or computer based instrumentation that can be used to monitor the operating condition of plant equipment, machinery and systems have provided the means to manage the maintenance operation. They have provided the means to reduce or eliminate unnecessary repairs, prevent catastrophic machine failures and reduce the negative impact of the maintenance operation on the profitability of manufacturing and production plants. Condition-based maintenance (CBM) techniques help determine the condition of in-service equipment in order to predict when maintenance should be performed. Most of the statistical learning techniques are only valid as long as the physics of a system does not change. If any significant change such as the replacement of a component or equipment occurs in the system, the statistical learning model should be re-trained or re-developed to adapt the new system. In this research, authors will propose a statistical learning framework which can be applicable for various CBMs, and the concept of the adaptive retraining technique will be described to support the execution of the framework so that the monitoring system does not need to be re-developed or re-trained even though there are any significant changes in the system or component

Developing optimized prioritizing road maintenance

Directory of Open Access Journals (Sweden)

Ewadh Hussein Ali

2018-01-01

Full Text Available Increased demand for efficient maintenance of the existing roadway system needs optimal usage of the allocated funds. The paper demonstrates optimized methods for prioritizing maintenance implementation projects. A selected zone of roadway system in Kerbala city represents the study area to demonstrate the application of the developed prioritization process. Paver system PAVER integrated with GIS is used to estimate and display the pavement condition index PCI, thereby to establish a priority of maintenance. In addition to simple ranking method by PCI produced by the output of PAVER, the paper introduces PCI measure for each section of roadway. The paper introduces ranking by multiple measures investigated through expert knowledge about measures that affect prioritization and their irrespective weights due to a predesigned questionnaire. The maintenance priority index (MPI is related to cost of suitable proposed maintenance, easiness of proposed maintenance, average daily traffic and functional classification of the roadway in addition to PCI. Further, incremental benefit-cost analysis ranking provide an optimized process due to benefit and cost of maintenance. The paper introduces efficient display of layout and ranking for the selected zone of roadway system based on MPI index and incremental BCR method. Although the two developed methods introduce different layout display for priority, statistical test shows that no significant difference between ranking of all methods of prioritization.

Risk-Based Predictive Maintenance for Safety-Critical Systems by Using Probabilistic Inference

Directory of Open Access Journals (Sweden)

Tianhua Xu

2013-01-01

Full Text Available Risk-based maintenance (RBM aims to improve maintenance planning and decision making by reducing the probability and consequences of failure of equipment. A new predictive maintenance strategy that integrates dynamic evolution model and risk assessment is proposed which can be used to calculate the optimal maintenance time with minimal cost and safety constraints. The dynamic evolution model provides qualified risks by using probabilistic inference with bucket elimination and gives the prospective degradation trend of a complex system. Based on the degradation trend, an optimal maintenance time can be determined by minimizing the expected maintenance cost per time unit. The effectiveness of the proposed method is validated and demonstrated by a collision accident of high-speed trains with obstacles in the presence of safety and cost constrains.

A multi-agent based intelligent configuration method for aircraft fleet maintenance personnel

OpenAIRE

Feng, Qiang; Li, Songjie; Sun, Bo

2014-01-01

A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The maintenance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance...

Development of electromagnetic induction diagnostics technology for condition based maintenance

International Nuclear Information System (INIS)

Mawatari, Shingo; Oeda, Kaoru; Yatogi, Hideo; Fukuchi, Taira; Ueno, Tadashi

2008-01-01

In ROKKASHO Reprocessing Plant (below, called 'RRP'), we have applied Condition Based Maintenance to rotating equipment with vibration diagnostics technology. However, a few rotating equipment are difficult to diagnose definitely, because have structural problems which exercise vibrational noise to peripheral and be impossible to install vibratory sensor. Electromagnetic induction diagnostics technology which measure magnetic fields to eddy current which is induced to rotary through static magnetic field, diagnose deterioration behavior such as abrasion and crack. As a result, it has possibilities to clear above problems. Therefore, we started our basic researches with this technology for Condition Based Maintenance. In this paper, it introduces basic data about 'Non-seal pump' that have installed in RRP. As a result, this technology is a possibility that be able to detect Condition Based Maintenance. (author)

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule-based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-oriented product data management (PDM) system.

Bayesian based Diagnostic Model for Condition based Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud; Sørensen, John Dalsgaard

2018-01-01

Operation and maintenance costs are a major contributor to the Levelized Cost of Energy for electricity produced by offshore wind and can be significantly reduced if existing corrective actions are performed as efficiently as possible and if future corrective actions are avoided by performing...... sufficient preventive actions. This paper presents an applied and generic diagnostic model for fault detection and condition based maintenance of offshore wind components. The diagnostic model is based on two probabilistic matrices; first, a confidence matrix, representing the probability of detection using...... for a wind turbine component based on vibration, temperature, and oil particle fault detection methods. The last part of the paper will have a discussion of the case study results and present conclusions....

A multi-agent based intelligent configuration method for aircraft fleet maintenance personnel

Directory of Open Access Journals (Sweden)

Feng Qiang

2014-04-01

Full Text Available A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The maintenance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance process is described as a 3-layer multi-agent system (MAS model. A communication and reasoning strategy among the agents is put forward. A fleet maintenance personnel configuration algorithm is proposed based on contract net protocol (CNP. Finally, a fleet of 10 aircraft is studied for verification purposes. A mission type with 3 waves of continuous dispatch is imaged. Compared with the traditional methods that can just provide configuration results, the proposed method can provide optimal maintenance strategies as well.

Knowledge acquisition for temporal abstraction.

Science.gov (United States)

Stein, A; Musen, M A; Shahar, Y

1996-01-01

Temporal abstraction is the task of detecting relevant patterns in data over time. The knowledge-based temporal-abstraction method uses knowledge about a clinical domain's contexts, external events, and parameters to create meaningful interval-based abstractions from raw time-stamped clinical data. In this paper, we describe the acquisition and maintenance of domain-specific temporal-abstraction knowledge. Using the PROTEGE-II framework, we have designed a graphical tool for acquiring temporal knowledge directly from expert physicians, maintaining the knowledge in a sharable form, and converting the knowledge into a suitable format for use by an appropriate problem-solving method. In initial tests, the tool offered significant gains in our ability to rapidly acquire temporal knowledge and to use that knowledge to perform automated temporal reasoning.

The knowledge base of journalism

DEFF Research Database (Denmark)

Svith, Flemming

In this paper I propose the knowledge base as a fruitful way to apprehend journalism. With the claim that the majority of practice is anchored in knowledge – understood as 9 categories of rationales, forms and levels – this knowledge base appears as a contextual look at journalists’ knowledge......, and place. As an analytical framework, the knowledge base is limited to understand the practice of newspaper journalists, but, conversely, the knowledge base encompasses more general beginnings through the inclusion of overall structural relationships in the media and journalism and general theories...... on practice and knowledge. As the result of an abductive reasoning is a theory proposal, there is a need for more deductive approaches to test the validity of this knowledge base claim. It is thus relevant to investigate which rationales are included in the knowledge base of journalism, as the dimension does...

Costs of performance based maintenance for local roads: Case study Albania

Science.gov (United States)

Jokanović, Igor; Grujić, Bojana; Zeljić, Dragana; Grujić, Žarko; Svilar, Mila

2017-12-01

The provision and maintenance of road infrastructure is a major global business, consequently it is essential that road maintenance services are provided in the most cost effective manner. Without regular maintenance, roads can rapidly fall into disrepair, preventing realization of the longer term impacts of road improvements on development, such as increased agricultural production and growth in school enrollment, which is of particular importance for a network of local (access) roads. Inadequate local roads maintenance in Albania is proposed to be solved by implementing performance based maintenance approach for which the costing exercise is presented within the paper.

Knowledge Acquisition Using Linguistic-Based Knowledge Analysis

Science.gov (United States)

Daniel L. Schmoldt

1998-01-01

Most knowledge-based system developmentefforts include acquiring knowledge from one or more sources. difficulties associated with this knowledge acquisition task are readily acknowledged by most researchers. While a variety of knowledge acquisition methods have been reported, little has been done to organize those different methods and to suggest how to apply them...

Open system architecture for condition based maintenance applied to a hydroelectric power plant

Energy Technology Data Exchange (ETDEWEB)

Amaya, E.J.; Alvares, A.J. [University of Brasilia (UnB), DF (Brazil). Mechanical and Mechatronic Dept.], Emails: eamaya@unb.br, alvares@AlvaresTech.com; Gudwin, R.R. [State University of Campinas (UNICAMP), SP (Brazil). Computer Engineering and Industrial Automation Dept.], E-mail: gudwin@dca.fee.unicamp.br

2009-07-01

The hydroelectric power plant of Balbina is implementing a condition based maintenance system applying an open, modular and scalable integrated architecture to provide comprehensive solutions and support to the end users like operational and maintenance team. The system called SIMPREBAL (Predictive Maintenance System of Balbina) is advocate of open standards, in particular through collaborative research programmers. In the developing is clearly understands the need for both, industry standards and a simple to use software development tool chain, supporting the development of complex condition based maintenance systems with multiple partners. The Open System Architecture for Condition Based Maintenance (OSA-CBM) is a standard that consider seven hierarchic layers that represent a logic transition or performed data flow from the data acquisition layer, through the intermediates layers as signal processing, condition monitor, health assessment, prognostics and decision support, to arrive to the presentation layer. SIMPREBAL is being implementing as an OSA-CBM software framework and tool set that allows the creation of truly integrated, comprehensive maintenance solutions through the internet. This paper identifies specific benefits of the application of the OSA-CBM in comprehensive solutions of condition based maintenance for a hydroelectric power plant. (author)

Intelligent Operation and Maintenance of Micro-grid Technology and System Development

Science.gov (United States)

Fu, Ming; Song, Jinyan; Zhao, Jingtao; Du, Jian

2018-01-01

In order to achieve the micro-grid operation and management, Studying the micro-grid operation and maintenance knowledge base. Based on the advanced Petri net theory, the fault diagnosis model of micro-grid is established, and the intelligent diagnosis and analysis method of micro-grid fault is put forward. Based on the technology, the functional system and architecture of the intelligent operation and maintenance system of micro-grid are studied, and the microcomputer fault diagnosis function is introduced in detail. Finally, the system is deployed based on the micro-grid of a park, and the micro-grid fault diagnosis and analysis is carried out based on the micro-grid operation. The system operation and maintenance function interface is displayed, which verifies the correctness and reliability of the system.

Foundation: Transforming data bases into knowledge bases

Science.gov (United States)

Purves, R. B.; Carnes, James R.; Cutts, Dannie E.

1987-01-01

One approach to transforming information stored in relational data bases into knowledge based representations and back again is described. This system, called Foundation, allows knowledge bases to take advantage of vast amounts of pre-existing data. A benefit of this approach is inspection, and even population, of data bases through an intelligent knowledge-based front-end.

Risk Based Maintenance in Electricity Network Organisations

NARCIS (Netherlands)

Mehairjan, R.P.Y.

2016-01-01

Presently, maintenance management of assets in infrastructure utilities such as electricity, gas and water are widely undergoing changes towards new working environments. These are mainly driven against the background of stringent regulatory regimes, an ageing asset base, increased customer demands

A Tailored Ontology Supporting Sensor Implementation for the Maintenance of Industrial Machines

Directory of Open Access Journals (Sweden)

Elaheh Maleki

2017-09-01

Full Text Available The longtime productivity of an industrial machine is improved by condition-based maintenance strategies. To do this, the integration of sensors and other cyber-physical devices is necessary in order to capture and analyze a machine’s condition through its lifespan. Thus, choosing the best sensor is a critical step to ensure the efficiency of the maintenance process. Indeed, considering the variety of sensors, and their features and performance, a formal classification of a sensor’s domain knowledge is crucial. This classification facilitates the search for and reuse of solutions during the design of a new maintenance service. Following a Knowledge Management methodology, the paper proposes and develops a new sensor ontology that structures the domain knowledge, covering both theoretical and experimental sensor attributes. An industrial case study is conducted to validate the proposed ontology and to demonstrate its utility as a guideline to ease the search of suitable sensors. Based on the ontology, the final solution will be implemented in a shared repository connected to legacy CAD (computer-aided design systems. The selection of the best sensor is, firstly, obtained by the matching of application requirements and sensor specifications (that are proposed by this sensor repository. Then, it is refined from the experimentation results. The achieved solution is recorded in the sensor repository for future reuse. As a result, the time and cost of the design process of new condition-based maintenance services is reduced.

A Tailored Ontology Supporting Sensor Implementation for the Maintenance of Industrial Machines.

Science.gov (United States)

Maleki, Elaheh; Belkadi, Farouk; Ritou, Mathieu; Bernard, Alain

2017-09-08

The longtime productivity of an industrial machine is improved by condition-based maintenance strategies. To do this, the integration of sensors and other cyber-physical devices is necessary in order to capture and analyze a machine's condition through its lifespan. Thus, choosing the best sensor is a critical step to ensure the efficiency of the maintenance process. Indeed, considering the variety of sensors, and their features and performance, a formal classification of a sensor's domain knowledge is crucial. This classification facilitates the search for and reuse of solutions during the design of a new maintenance service. Following a Knowledge Management methodology, the paper proposes and develops a new sensor ontology that structures the domain knowledge, covering both theoretical and experimental sensor attributes. An industrial case study is conducted to validate the proposed ontology and to demonstrate its utility as a guideline to ease the search of suitable sensors. Based on the ontology, the final solution will be implemented in a shared repository connected to legacy CAD (computer-aided design) systems. The selection of the best sensor is, firstly, obtained by the matching of application requirements and sensor specifications (that are proposed by this sensor repository). Then, it is refined from the experimentation results. The achieved solution is recorded in the sensor repository for future reuse. As a result, the time and cost of the design process of new condition-based maintenance services is reduced.

Optimizing preventive maintenance with maintenance templates

International Nuclear Information System (INIS)

Dozier, I.J.

1996-01-01

Rising operating costs has caused maintenance professionals to rethink their strategy for preventive maintenance (PM) programs. Maintenance Templates are pre-engineered PM task recommendations for a component type based on application of the component. Development of the maintenance template considers the dominant failure cause of the component and the type of preventive maintenance that can predict or prevent the failure from occurring. Maintenance template development also attempts to replace fixed frequency tasks with condition monitoring tasks such as vibration analysis or thermography. For those components that have fixed frequency PM intervals, consideration is given to the maintenance drivers such as criticality, environment and usage. This helps to maximize the PM frequency intervals and maximize the component availability. Maintenance Templates have been used at PECO Energy's Limerick Generating Station during the Reliability Centered Maintenance (RCM) Process to optimize their PM program. This paper describes the development and uses of the maintenance templates

Maintenance Management Support Systems for component aging estimation at nuclear power plants

International Nuclear Information System (INIS)

Shimizu, Shunichi; Ando, Yasumasa; Morioka, Toshihiko; Okuzumi, Naoaki

1991-01-01

Maintenance Management Support Systems (MMSSs) for nuclear power plants have been developed using component aging estimation methods and decision tree analysis for maintenance planning. The former evaluates actual component reliability through statistical analysis on field maintenance data. The latter provides preventive maintenance (PM) planning guidance using heuristic expert knowledge and estimated reliability parameters. The following aspects have been investigated: (1) A systematic and effective method of managing components/parts design information and field maintenance data (2) A method for estimating component aging based on a statistical analysis of field maintenance data (3) A method for providing PM planning guidance using estimated component reliability/performance parameters and decision tree analysis. Based on these investigations, two MMSSs were developed. One deals with 'general maintenance data', which are common to all component types and are amenable to common data handling. The other system deals with 'specific maintenance data', which are specific to an individual component type. Both systems provide PM planning guidance for PM cycles propriety and the PM work priority. The function of these systems were verified using simulated maintenance data. (author)

One knowledge base or many knowledge pools?

DEFF Research Database (Denmark)

Lundvall, Bengt-Åke

It is increasingly realized that knowledge is the most important resource and that learning is the most important process in the economy. Sometimes this is expressed by coining the current era as characterised by a ‘knowledge based economy'. But this concept might be misleading by indicating...... that there is one common knowledge base on which economic activities can be built. In this paper we argue that it is more appropriate to see the economy as connecting to different ‘pools of knowledge'. The argument is built upon a conceptual framework where we make distinctions between private/public, local....../global, individual/collective and tacit/codified knowledge. The purpose is both ‘academic' and practical. Our analysis demonstrates the limits of a narrowly economic perspective on knowledge and we show that these distinctions have important implications both for innovation policy and for management of innovation....

A full life cycle nuclear knowledge management framework based on digital system

International Nuclear Information System (INIS)

Wang, Minglu; Zheng, Mingguang; Tian, Lin; Qiu, Zhongming; Li, Xiaoyan

2017-01-01

Highlights: • A full life cycle nuclear power plant knowledge management framework is introduced. • This framework benefits the safe design, construction, operation and maintenance. • This framework enhances safety, economy and reliability of nuclear power plant. - Abstract: The nuclear power plant is highly knowledge-intensive facility. With the rapid advent and development of modern information and communication technology, knowledge management in nuclear industry has been provided with new approaches and possibilities. This paper introduces a full cycle nuclear power plant knowledge management framework based on digital system and tries to find solutions to knowledge creation, sharing, transfer, application and further innovation in nuclear industry. This framework utilizes information and digital technology to build top-tier object driven work environment, automatic design and analysis integration platform, digital dynamic performance Verification & Validation (V&V) platform, collaborative manufacture procedure, digital construction platform, online monitoring and configuration management which benefit knowledge management in NPP full life cycle. The suggested framework will strengthen the design basis of the nuclear power plants (NPPs) and will ensure the safety of the NPP design throughout the whole lifetime of the plant.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far'few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces correaponding formal rules, rulebased reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally,the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-ori-ented product data management (PDM) system.

TMS for Instantiating a Knowledge Base With Incomplete Data

Science.gov (United States)

James, Mark

2007-01-01

A computer program that belongs to the class known among software experts as output truth-maintenance-systems (output TMSs) has been devised as one of a number of software tools for reducing the size of the knowledge base that must be searched during execution of artificial- intelligence software of the rule-based inference-engine type in a case in which data are missing. This program determines whether the consequences of activation of two or more rules can be combined without causing a logical inconsistency. For example, in a case involving hypothetical scenarios that could lead to turning a given device on or off, the program determines whether a scenario involving a given combination of rules could lead to turning the device both on and off at the same time, in which case that combination of rules would not be included in the scenario.

A CMMS Expert using BIM for IBS Building Maintenance

Directory of Open Access Journals (Sweden)

Hamzah Noraini

2016-01-01

Full Text Available In the IBS building maintenance, the conventional methods to the project delivery and its failure to form effective communication channel between complementary knowledge on IBS construction and related members that is conducted in the sequential manner has resulted in ineffectiveness for managing building maintenance, where a paradigm shift within the IBS traditional approach is necessary. The research results described are concerned with i an integrated system to record, diagnose and analyse information for IBS building maintenance to detect patent or latent defect, select an effective repair method, provide appropriate planning decision and reduce risks of defect throughout the building lifetime. ii building a decision making support in diagnosis in IBS building maintenance based on robust data collection about concrete defects and causes including in the selection of a durable replacement design and material or the proper rehabilitation method. The system development was based on analysis of number of interviews and case studies conducted with professional engineers working in IBS building maintenance departments. The paper concludes that implementing a CMMS Expert using BIM can help improve the performance of IBS building design, construction and maintenance operations.

Knowledge representation and knowledge base design for operator advisor system

International Nuclear Information System (INIS)

Hangos, K.M.; Sziano, T.; Tapolcai, L.

1990-01-01

The problems of knowledge representation, knowledge base handling and design has been described for an Operator Advisor System in the Paks Nuclear Power Plant. The Operator Advisor System is to be implemented as a part of the 5th and 6th unit. The knowledge of the Operator Advisor system is described by a few elementary knowledge items (diagnostic event functions, fault graph, action trees), weighted directed graphs have been found as their common structure. List-type and relational representation of these graphs have been used for the on-line and off-line part of the knowledge base respectively. A uniform data base design and handling has been proposed which consists of a design system, a knowledge base editor and a knowledge base compiler

Maintenance of Certification for Radiation Oncology

International Nuclear Information System (INIS)

Kun, Larry E.; Ang, Kian; Erickson, Beth; Harris, Jay; Hoppe, Richard; Leibel, Steve; Davis, Larry; Hattery, Robert

2005-01-01

Maintenance of Certification (MOC) recognizes that in addition to medical knowledge, several essential elements involved in delivering quality care must be developed and maintained throughout one's career. The MOC process is designed to facilitate and document professional development of American Board of Radiology (ABR) diplomates in the essential elements of quality care in Radiation Oncology and Radiologic Physics. ABR MOC has been developed in accord with guidelines of the American Board of Medical Specialties. All Radiation Oncology certificates issued since 1995 are 10-year, time-limited certificates; diplomates with time-limited certificates who wish to maintain specialty certification must complete specific requirements of the American Board of Radiology MOC program. Diplomates with lifelong certificates are not required to participate but are strongly encouraged to do so. Maintenance of Certification is based on documentation of participation in the four components of MOC: (1) professional standing, (2) lifelong learning and self-assessment, (3) cognitive expertise, and (4) performance in practice. Through these components, MOC addresses six competencies-medical knowledge, patient care, interpersonal and communication skills, professionalism, practice-based learning and improvement, and systems-based practice. Details of requirements for components 1, 2, and 3 of MOC are outlined along with aspects of the fourth component currently under development

Risk-Based Operation and Maintenance Planning for Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2010-01-01

Operation and maintenance (O&M) are large contributors to the cost of energy for offshore wind turbines. Optimal planning of O&M should include use of inspections and monitoring results to make decisions that minimize the expected costs through the lifetime of the structures. For offshore...... structures it is especially important because of the dependence on weather windows for inspections and repairs to be possible. A model has been developed to estimate the expected costs to corrective and condition based maintenance for a wind turbine with a single component. The deterioration of the component...... is simulated, and the expected costs are found for different strategies. An application example shows that condition based maintenance has the potential of reducing the costs, and a risk based approach can be used to find the optimal strategy for O&M. Further the influence of failure rate and damage parameters...

Aging based maintenance and reinvestment scheduling of electric distribution

Energy Technology Data Exchange (ETDEWEB)

Korpijarvi, J.

2012-07-01

The maintenance of electric distribution network is a topical question for distribution system operators because of increasing significance of failure costs. In this dissertation the maintenance practices of the distribution system operators are analyzed and a theory for scheduling maintenance activities and reinvestment of distribution components is created. The scheduling is based on the deterioration of components and the increasing failure rates due to aging. The dynamic programming algorithm is used as a solving method to maintenance problem which is caused by the increasing failure rates of the network. The other impacts of network maintenance like environmental and regulation reasons are not included to the scope of this thesis. Further the tree trimming of the corridors and the major disturbance of the network are not included to the problem optimized in this thesis. For optimizing, four dynamic programming models are presented and the models are tested. Programming is made in VBA-language to the computer. For testing two different kinds of test networks are used. Because electric distribution system operators want to operate with bigger component groups, optimal timing for component groups is also analyzed. A maintenance software package is created to apply the presented theories in practice. An overview of the program is presented (orig.)

Structuring AHP-based maintenance policy selection

NARCIS (Netherlands)

Goossens, Adriaan; Basten, Robertus Johannes Ida; Hummel, J. Marjan; van der Wegen, Leonardus L.M.

2015-01-01

We aim to structure the maintenance policy selection process for ships, using the Analytic Hierarchy Process (AHP). Maintenance is an important contributor to reach the intended life-time of capital technical assets, and it is gaining increasing interest and relevance. A maintenance policy is a

PERFORMANCE-BASED CONTRACTING IN CONSTRUCTION PHASE AND MAINTENANCE PHASE OF PAVEMENT

Science.gov (United States)

Yoshida, Takeshi

Performance-based contracting for pavement in Japan started as performance warranties in construction phase, in 1999. Recently, road agencies have recognized the applicability of this type of contracting in outsourcing of maintenance activities. The objectives of this study are to clarify the issues of performance specifying in construction phase and maintenance phase of pavement, and to propose measures to be taken. This paper, with the recognition that the life of each pavement depends on performance standards for various attributes, reviews domestic and foreign examples of performance-based contracting. A performance standard based on the average of current practices can enhance product quality and service life with a warranty contract. Repair thresholds and response time for each deficiency should be considered as performance standards in maintenance phase.

Failure and Maintenance Analysis Using Web-Based Reliability Database System

International Nuclear Information System (INIS)

Hwang, Seok Won; Kim, Myoung Su; Seong, Ki Yeoul; Na, Jang Hwan; Jerng, Dong Wook

2007-01-01

Korea Hydro and Nuclear Power Company has lunched the development of a database system for PSA and Maintenance Rule implementation. It focuses on the easy processing of raw data into a credible and useful database for the risk-informed environment of nuclear power plant operation and maintenance. Even though KHNP had recently completed the PSA for all domestic NPPs as a requirement of the severe accident mitigation strategy, the component failure data were only gathered as a means of quantification purposes for the relevant project. So, the data were not efficient enough for the Living PSA or other generic purposes. Another reason to build a real time database is for the newly adopted Maintenance Rule, which requests the utility to continuously monitor the plant risk based on its operation and maintenance performance. Furthermore, as one of the pre-condition for the Risk Informed Regulation and Application, the nuclear regulatory agency of Korea requests the development and management of domestic database system. KHNP is stacking up data of operation and maintenance on the Enterprise Resource Planning (ERP) system since its first opening on July, 2003. But, so far a systematic review has not been performed to apply the component failure and maintenance history for PSA and other reliability analysis. The data stored in PUMAS before the ERP system is introduced also need to be converted and managed into the new database structure and methodology. This reliability database system is a web-based interface on a UNIX server with Oracle relational database. It is designed to be applicable for all domestic NPPs with a common database structure and the web interfaces, therefore additional program development would not be necessary for data acquisition and processing in the near future. Categorization standards for systems and components have been implemented to analyze all domestic NPPs. For example, SysCode (for a system code) and CpCode (for a component code) were newly

Design of Mobile Operation and Maintenance System Based on Power GIS and GPS

Directory of Open Access Journals (Sweden)

Jing TAO

2017-01-01

Full Text Available In order to solve the low efficiency of operation and maintenance and the problems of management coordination caused by the coexistence of off-line operation and maintenance and multi system coexistence in current power telecommunication operation and maintenance, this paper proposes a mobile operation and maintenance system based on power GIS and GPS location technology. The system is based on the C/S architecture, and the mobile operation and maintenance terminal is connected with the operation and maintenance management terminal through wireless and wired network. In addition to meeting basic business requirements, the system integrates power GIS functions to visually demonstrate communication resources, personnel, and failures. The staff can use the wireless mobile terminal which integrated GPS module for to operate and maintain, and can locate accurately in real time.

A novel integrated condition-based maintenance and stochastic flexible job shop scheduling problem

DEFF Research Database (Denmark)

Rahmati, Seyed Habib A.; Ahmadi, Abbas; Govindan, Kannan

2018-01-01

the level of the system optimization. By means of this equipment, managers can benefit from a condition-based maintenance (CBM) for monitoring and managing their system. The chief aim of the paper is to develop a stochastic maintenance problem based on CBM activities engaged with a complex applied......Integrated consideration of production planning and maintenance processes is a real world assumption. Specifically, by improving the monitoring equipment such as various sensors or product-embedded information devices in recent years, joint assessment of these processes is inevitable for enhancing...... production problem called flexible job shop scheduling problem (FJSP). This integrated problem considers two maintenance scenarios in terms of corrective maintenance (CM) and preventive maintenance (PM). The activation of scenario is done by monitoring the degradation condition of the system and comparing...

A COMPUTER BASED MAINTENANCE MANAGEMENT SYSTEM ...

African Journals Online (AJOL)

... programs to schedule for maintenance or replacement of machines has been designed such that it enables the maintenance department control all jobs associated with plant maintenance and breakdown. It predicts the time to failure of designated plants and caters for the replacement analysis of some capital equipment.

A review on condition-based maintenance optimization models for stochastically deteriorating system

International Nuclear Information System (INIS)

Alaswad, Suzan; Xiang, Yisha

2017-01-01

Condition-based maintenance (CBM) is a maintenance strategy that collects and assesses real-time information, and recommends maintenance decisions based on the current condition of the system. In recent decades, research on CBM has been rapidly growing due to the rapid development of computer-based monitoring technologies. Research studies have proven that CBM, if planned properly, can be effective in improving equipment reliability at reduced costs. This paper presents a review of CBM literature with emphasis on mathematical modeling and optimization approaches. We focus this review on important aspects of the CBM, such as optimization criteria, inspection frequency, maintenance degree, solution methodology, etc. Since the modeling choice for the stochastic deterioration process greatly influences CBM strategy decisions, this review classifies the literature on CBM models based on the underlying deterioration processes, namely discrete- and continuous-state deterioration, and proportional hazard model. CBM models for multi-unit systems are also reviewed in this paper. This paper provides useful references for CBM management professionals and researchers working on CBM modeling and optimization. - Highlights: • A review on Condition-based maintenance (CBM) optimization models is presented. • The CBM models are classified based on the underlying deterioration processes. • Existing CBM models for both single- and multi-unit systems are reviewed. • Future essential research directions on CBM are identified.

Fuzzy knowledge bases integration based on ontology

OpenAIRE

Ternovoy, Maksym; Shtogrina, Olena

2012-01-01

the paper describes the approach for fuzzy knowledge bases integration with the usage of ontology. This approach is based on metadata-base usage for integration of different knowledge bases with common ontology. The design process of metadata-base is described.

Knowledge-based Telecom Industry

OpenAIRE

Vinje, Villeman; Nordkvelde, Marius

2011-01-01

BI Norwegian School of Management is conducting a national research project entitled “A knowledge-based Norway”. Thirteen major knowledge-based industries in Norway are being analyzed under the auspices of the project. This study assesses the underlying properties of a global knowledge hub to examine the extent to which the Norwegian telecom industry – which encompasses all telecom firms located in Norway regardless of ownership – constitutes a global knowledge hub. It commences with a ge...

Study on Maintenance Practices for School Buildings in Terengganu and Kedah, Malaysia

Directory of Open Access Journals (Sweden)

Mohammad Ropi R.

2014-03-01

Full Text Available Malaysia initiated talks on building maintenance in 1971 during the Second Malaysia Plan of 1971-1975. Later, the government introduced the Building and Common Property (Maintenance and Management Act, 2007 to provide proper maintenance and management of buildings. School buildings are one of the important facilities for basic knowledge in everyday life. Accordingly, the maintenance of school buildings, which serve staff and students, needs considerable attention as effective maintenance protects capital investment, ensures the health and safety of the children, and supports educational performance. Based on a combination of literature survey and questionnaire appraisal, this study evaluates the maintenance practices in designated schools in Malaysia. Overall, the study showed that most of the school buildings do not possess their own maintenance management practices. Moreover, no preventive or planned maintenance was observed, and only emergency maintenance was applied when necessary. The study recommends the implementation of planned maintenance practices, which will be more effective than unplanned maintenance, mostly because of the reduction in repair costs.

Analytical method for optimization of maintenance policy based on available system failure data

International Nuclear Information System (INIS)

Coria, V.H.; Maximov, S.; Rivas-Dávalos, F.; Melchor, C.L.; Guardado, J.L.

2015-01-01

An analytical optimization method for preventive maintenance (PM) policy with minimal repair at failure, periodic maintenance, and replacement is proposed for systems with historical failure time data influenced by a current PM policy. The method includes a new imperfect PM model based on Weibull distribution and incorporates the current maintenance interval T 0 and the optimal maintenance interval T to be found. The Weibull parameters are analytically estimated using maximum likelihood estimation. Based on this model, the optimal number of PM and the optimal maintenance interval for minimizing the expected cost over an infinite time horizon are also analytically determined. A number of examples are presented involving different failure time data and current maintenance intervals to analyze how the proposed analytical optimization method for periodic PM policy performances in response to changes in the distribution of the failure data and the current maintenance interval. - Highlights: • An analytical optimization method for preventive maintenance (PM) policy is proposed. • A new imperfect PM model is developed. • The Weibull parameters are analytically estimated using maximum likelihood. • The optimal maintenance interval and number of PM are also analytically determined. • The model is validated by several numerical examples

Risk-based equipment removal guide for on-line maintenance at PSE ampersand G

International Nuclear Information System (INIS)

Knoll, A.; Smith, C.; Pollock, J.

1995-01-01

On-line maintenance plays an important role in achieving safe and reliable power generation in a nuclear power plant. However, maintenance, if not properly planned and performed, may also be an important contributor to plant risk. Therefore, plant-specific procedures are needed for equipment removal from service to enhance the benefits of on-line maintenance and minimize the risks involved. The problem is to identify and implement the most effective on-line maintenance policy in the form of a proceduralized guide to assure plant safety under various operation and maintenance constraints. This paper presents a methodology to develop plant-specific on-line maintenance strategies and acceptance criteria using a multivariate safety approach based on risk assessment. Based on plant-specific data as modeled in the individual plant evaluation (IPE) and the updated probabilistic safety assessment (PSA), the risk-based methodology is currently being applied to the development of proceduralized equipment removal guides at Hope Creek and Salem units 1 and 2 of Public Service Electric and Gas Company (PSE ampersand G)

Heuristic hybrid game approach for fleet condition-based maintenance planning

International Nuclear Information System (INIS)

Feng, Qiang; Bi, Xiong; Zhao, Xiujie; Chen, Yiran; Sun, Bo

2017-01-01

The condition-based maintenance (CBM) method is commonly used to select appropriate maintenance opportunities according to equipment status over a period of time. The CBM of aircraft fleets is a fleet maintenance planning problem. In this problem, mission requirements, resource constraints, and aircraft statuses are considered to find an optimal strategy set. Given that the maintenance strategies for each aircraft are finite, fleet CBM can be treated as a combinatorial optimization problem. In this study, the process of making a decision on the CBM of military fleets is analyzed. The fleet CBM problem is treated as a two-stage dynamic decision-making problem. Aircraft are divided into dispatch and standby sets; thus, the problem scale is significantly reduced. A heuristic hybrid game (HHG) approach comprising a competition game and a cooperative game is proposed on the basis of heuristic rule. In the dispatch set, a competition game approach is proposed to search for a local optimal strategy matrix. A cooperative game method for the two sets is also proposed to ensure global optimization. Finally, a case study regarding a fleet comprising 20 aircraft is conducted, with the results proving that the approach efficiently generates outcomes that meet the mission risk-oriented schedule requirement. - Highlights: • A new heuristic hybrid game method for fleet condition-based maintenance is proposed. • The problem is simplified by hierarchical solving based on dispatch and standby set. • The local optimal solution is got by competition game algorithm for dispatch set. • The global optimal solution is got by cooperative game algorithm between two sets.

A knowledge base architecture for distributed knowledge agents

Science.gov (United States)

Riedesel, Joel; Walls, Bryan

1990-01-01

A tuple space based object oriented model for knowledge base representation and interpretation is presented. An architecture for managing distributed knowledge agents is then implemented within the model. The general model is based upon a database implementation of a tuple space. Objects are then defined as an additional layer upon the database. The tuple space may or may not be distributed depending upon the database implementation. A language for representing knowledge and inference strategy is defined whose implementation takes advantage of the tuple space. The general model may then be instantiated in many different forms, each of which may be a distinct knowledge agent. Knowledge agents may communicate using tuple space mechanisms as in the LINDA model as well as using more well known message passing mechanisms. An implementation of the model is presented describing strategies used to keep inference tractable without giving up expressivity. An example applied to a power management and distribution network for Space Station Freedom is given.

Maintenance training - a modern necessity

International Nuclear Information System (INIS)

Bushall, W.

1987-01-01

In recent years, there has been an increase in technically advanced systems and equipment and a need for highly skilled and knowledgeable maintenance technicians to maintain them. To implement an effective training program, training groups' and plant staffs' key to success must be cooperation and creativity. This paper deals with plant staff interface and how to effectively conduct performance-based training while holding the line on costs. This paper includes cost effective and innovative measures to produce performance-based training for maintenance disciplines including: Using the plants staff as a resource as subject matter experts in the development and verification of training materials. Using the plant staff as a resource for the construction of training aids. Using salvage and surplus to produce high quality, low cost training aids. Using cutaways for better understanding of he theory of equipment operation. These cost saving practices are currently being used at Gulf States Utilities' River Bend Nuclear Station

Research of nuclear power plant in-service maintenance based on virtual reality

International Nuclear Information System (INIS)

Wang Yong; Kuang Weijun

2015-01-01

This paper presents a method of constructing nuclear power plant in-service maintenance virtual simulation scene and virtual maintenance process. Taking air baffles dismantling process of CAP1400(China Advanced Passive 1400) nuclear power plant as an instance, this paper discusses ergonomics, space analysis, time assessment based on virtual reality in the process of in-service maintenance. It demonstrates the advantage of using VR technology to design and verify in-service maintenance process of nuclear power plant compared to the conventional way. (author)

Experience based reliability centered maintenance

International Nuclear Information System (INIS)

Haenninen, S.; Laakso, K.

1993-03-01

The systematic analysis and documentation of operating experiences should be included in a living NPP life management program. Failure mode and effects and maintenance effects analyses are suitable methods for analysis of the failure and corrective maintenance experiences of equipment. Combined use of the information on occurred functional failures and the decision tree logic of the reliability centered maintenance identifies applicable and effective preventive maintenance tasks of equipment in an old plant. In this study the electrical motor drives of closing and isolation valves (MOV) of TVO and Loviisa nuclear power plants were selected to serve as pilot study objects. The study was limited to valve drives having actuators manufactured by AUMA in Germany. The fault and maintenance history of MOVs from 1981 up to and including October 1991 in different safety and process systems at TVO 1 and 2 nuclear power units was at first analyzed in a systematic way. The scope of the components studied was 81 MOVs in safety-related systems and 127 other MOVs per each TVO unit. In the case of the Loviisa plant, the observation period was limited to three years, i.e. from February 1989 up to February 1992. The scope of the Loviisa 1 and 2 components studied was 44 respectively 95 MOVs. (25 refs., 22 figs., 8 tabs.)

A condition-based maintenance policy for multi-component systems with a high maintenance setup cost

NARCIS (Netherlands)

Zhu, Q.; Peng, H.; Houtum, van G.J.J.A.N.

2015-01-01

Condition-based maintenance (CBM) is becoming increasingly important due to the development of advanced sensor and information technology, which facilitates the remote collection of condition data. We propose a new CBM policy for multi-component systems with continuous stochastic deteriorations. To

Developing Mobile- and BIM-Based Integrated Visual Facility Maintenance Management System

Directory of Open Access Journals (Sweden)

Yu-Cheng Lin

2013-01-01

Full Text Available Facility maintenance management (FMM has become an important topic for research on the operation phase of the construction life cycle. Managing FMM effectively is extremely difficult owing to various factors and environments. One of the difficulties is the performance of 2D graphics when depicting maintenance service. Building information modeling (BIM uses precise geometry and relevant data to support the maintenance service of facilities depicted in 3D object-oriented CAD. This paper proposes a new and practical methodology with application to FMM using BIM technology. Using BIM technology, this study proposes a BIM-based facility maintenance management (BIMFMM system for maintenance staff in the operation and maintenance phase. The BIMFMM system is then applied in selected case study of a commercial building project in Taiwan to verify the proposed methodology and demonstrate its effectiveness in FMM practice. Using the BIMFMM system, maintenance staff can access and review 3D BIM models for updating related maintenance records in a digital format. Moreover, this study presents a generic system architecture and its implementation. The combined results demonstrate that a BIMFMM-like system can be an effective visual FMM tool.

Maintenance management for nuclear power plant 'Integrated valve maintenance'

International Nuclear Information System (INIS)

Gerner, P.; Zanner, G.

2001-01-01

The deregulation of Europe's power market does force many utilities, and especially nuclear power plant operators, to introduce extensive cost-cutting measures in order to be able to compete within this new environment. The optimization of plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing e.g. expenditure on maintenance. Siemens Nuclear Power GmbH, in cooperation with plant operators, is currently implementing new and improved service concepts which can have a major effect on the way in which maintenance will be performed in the future. Innovative service packages for maintenance in nuclear power plants are available which can be used to perform a time- and cost-effective maintenance. The concepts encompass optimization of the overall sequence from planning in advance to the individual measures including reduction of the scope of maintenance activities, identification of cost cutting potential and bundling of maintenance activities. The main features of these maintenance activities are illustrated here using the examples of outage planning and integrated valve maintenance. In nuclear power plants approx. 5000 valves are periodically preventively, condition-based or breakdown-based maintained. Because of this large number of valves to be maintained a high potential of improvements and cost reductions can be achieved by performing an optimized, cost-effective maintenance based on innovative methods and tools. Siemens Nuclear Power GmbH has developed and qualified such tools which allow to reduce service costs while maintaining high standards of safety and availability. By changing from preventive to predictive (condition-based) maintenance - the number of valves to be maintained may be reduced considerably. The predictive maintenance is based on the Siemens Nuclear Power GmbH diagnostic and evaluation method (ADAM). ADAM is used to monitor the operability of valves by analytical verification of

SOFTM: a software maintenance expert system in Prolog

DEFF Research Database (Denmark)

Pau, L.; Negret, J. M.

1988-01-01

A description is given of a knowledge-based system called SOFTM, serving the following purposes: (1) assisting a software programmer or analyst in his application code maintenance tasks, (2) generating and updating automatically software correction documentation, (3) helping the end user register......, and on interfacing capabilities of Prolog II to a variety of other languages...

A comprehensive approach to RCM-based preventive maintenance program development

International Nuclear Information System (INIS)

Hall, B.E.; Davis, T.; Pennington, A.J.

1988-01-01

In late 1986, Public Service Electric and Gas Company (PSE ampersand G) concluded that to support its vision and strategic planning it would be necessary to develop a consistent approach to maintenance for all nuclear units at the artificial island. General Physics Corporation was selected to lead a consultant team to support full-scale development of a preventive maintenance (PM) program for Salem and Hope Creek generating stations based on a reliability-centered maintenance (RCM) approach. RCM was selected because it represents a systematic approach to developing a PM program that provides a logical, consistent, and traceable methodology and produces a well-documented engineering basis for the program. Early in 1987, primary objectives for the PM program were defined. The Phase I tasks addressed key programmatic areas such as maintenance philosophy, procedures, condition monitoring, performance trending, equipment failure data base, ogranization, PM program effectiveness evaluation, RCM process, reliability/availability modeling, information management, training, spare parts, software/hardware, and commitments. Phase I of the PM program development project was completed in January 1988. Highlights of the Phase I work and the PM program manual are described

Game-Theoretic Models for Usage-based Maintenance Contract

Science.gov (United States)

Husniah, H.; Wangsaputra, R.; Cakravastia, A.; Iskandar, B. P.

2018-03-01

A usage-based maintenance contracts with coordination and non coordination between two parties is studied in this paper. The contract is applied to a dump truck operated in a mining industry. The situation under study is that an agent offers service contract to the owner of the truck after warranty ends. This contract has only a time limit but no usage limit. If the total usage per period exceeds the maximum usage allowed in the contract, then the owner will be charged an additional cost. In general, the agent (Original Equipment Manufacturer/OEM) provides a full coverage of maintenance, which includes PM and CM under the lease contract. The decision problem for the owner is to select the best option offered that fits to its requirement, and the decision problem for the agent is to find the optimal maintenance efforts for a given price of the service option offered. We first find the optimal decisions using coordination scheme and then with non coordination scheme for both parties.

A Costing Analysis for Decision Making Grid Model in Failure-Based Maintenance

Directory of Open Access Journals (Sweden)

Burhanuddin M. A.

2011-01-01

Full Text Available Background. In current economic downturn, industries have to set good control on production cost, to maintain their profit margin. Maintenance department as an imperative unit in industries should attain all maintenance data, process information instantaneously, and subsequently transform it into a useful decision. Then act on the alternative to reduce production cost. Decision Making Grid model is used to identify strategies for maintenance decision. However, the model has limitation as it consider two factors only, that is, downtime and frequency of failures. We consider third factor, cost, in this study for failure-based maintenance. The objective of this paper is to introduce the formulae to estimate maintenance cost. Methods. Fish bone analysis conducted with Ishikawa model and Decision Making Grid methods are used in this study to reveal some underlying risk factors that delay failure-based maintenance. The goal of the study is to estimate the risk factor that is, repair cost to fit in the Decision Making Grid model. Decision Making grid model consider two variables, frequency of failure and downtime in the analysis. This paper introduces third variable, repair cost for Decision Making Grid model. This approaches give better result to categorize the machines, reduce cost, and boost the earning for the manufacturing plant. Results. We collected data from one of the food processing factories in Malaysia. From our empirical result, Machine C, Machine D, Machine F, and Machine I must be in the Decision Making Grid model even though their frequency of failures and downtime are less than Machine B and Machine N, based on the costing analysis. The case study and experimental results show that the cost analysis in Decision Making Grid model gives more promising strategies in failure-based maintenance. Conclusions. The improvement of Decision Making Grid model for decision analysis with costing analysis is our contribution in this paper for

Performance-based maintenance procurement by Dutch housing associations

NARCIS (Netherlands)

Straub, A.

2004-01-01

OTB Research institute has established a long-term research program to performance-based maintenance procurement in the technical management of housing stock. Stakeholders: housing associations, contractors and the Dutch Building Research Foundation are directly involved in this research program.

A reliability-based maintenance technicians' workloads optimisation model with stochastic consideration

Science.gov (United States)

Ighravwe, D. E.; Oke, S. A.; Adebiyi, K. A.

2016-06-01

The growing interest in technicians' workloads research is probably associated with the recent surge in competition. This was prompted by unprecedented technological development that triggers changes in customer tastes and preferences for industrial goods. In a quest for business improvement, this worldwide intense competition in industries has stimulated theories and practical frameworks that seek to optimise performance in workplaces. In line with this drive, the present paper proposes an optimisation model which considers technicians' reliability that complements factory information obtained. The information used emerged from technicians' productivity and earned-values using the concept of multi-objective modelling approach. Since technicians are expected to carry out routine and stochastic maintenance work, we consider these workloads as constraints. The influence of training, fatigue and experiential knowledge of technicians on workload management was considered. These workloads were combined with maintenance policy in optimising reliability, productivity and earned-values using the goal programming approach. Practical datasets were utilised in studying the applicability of the proposed model in practice. It was observed that our model was able to generate information that practicing maintenance engineers can apply in making more informed decisions on technicians' management.

Six Sigma methodology as a road to intelligent maintenance

Directory of Open Access Journals (Sweden)

Michał Zasadzień

2017-06-01

Full Text Available An enterprise which is managed in a modern way should be based on the concept of knowledge management. It is particularly important in the case of processes related to facility maintenance, where the efficiency and effectiveness of work is directly connected with the employees’ knowledge. Improvement of processes involved in facility maintenance has a real influence on the productivity of a manufacturing enterprise. High accessibility of technical equipment and its correct functioning influence not only production efficiency but also the quality of products and the safety of operators. The article is a description of an attempt to implement one of quality engineering methods for improving the facility maintenance process. The author decided to use the 8D method to shorten the duration of downtimes caused by breakdowns. Owing to the conducted analysis and the implementation of the improvement and preventive actions, we were able to shorten the duration of a downtime of a machine having a crucial importance for the company. Investigations and implementation were conducted in one of Silesian production plants.

Logically automorphically equivalent knowledge bases

OpenAIRE

Aladova, Elena; Plotkin, Tatjana

2017-01-01

Knowledge bases theory provide an important example of the field where applications of universal algebra and algebraic logic look very natural, and their interaction with practical problems arising in computer science might be very productive. In this paper we study the equivalence problem for knowledge bases. Our interest is to find out how the informational equivalence is related to the logical description of knowledge. Studying various equivalences of knowledge bases allows us to compare d...

JRR-3 maintenance program utilizing accumulated maintenance data

International Nuclear Information System (INIS)

Izumo, Hironobu; Kato, Tomoaki; Kinase, Masami; Torii, Yoshiya; Murayama, Yoji

2007-07-01

JRR-3(Japan Research Reactor No.3) has been operated for more than 15 years after the modification, without significant troubles by carrying out maintenance such as the preventive maintenance (mainly time-based maintenance) for the safety-grade equipments and the breakdown maintenance for the non-safety-grade equipments. Unscheduled shutdowns causes by aged non-safety-grade equipments have been increasing, and the resources such as budgets have been decreasing year by year. In this situation, JRR-3 maintenance program was reviewed about safety, reliability and economic efficiency. This report offers the policy of the maintenance review and the future direction of maintenance programs. (author)

Development of maintenance tools based on tribology for nuclear power plant

International Nuclear Information System (INIS)

Iwai, Yoshiro; Honda, Tomomi; Yoshinaga, Shigeki

2007-01-01

Many tribological problems occur in the maintenance of nuclear power plants. In this paper, we introduced our developed maintenance tools based on tribology such as a particle counter and wear sensors. Their principals were shown briefly and their usefulness was clarified by the experiments on monitoring of wear. (author)

An Abstraction Hierarchy based mobile PC display design in NPP maintenance considering the level of expertise

International Nuclear Information System (INIS)

Yim, Ho Bin; Kim, In; Seong, Poong Hyun

2011-01-01

Research highlights: → Six levels of Abstraction Hierarchy based information for maintenance were proposed. → Errors and workload with AH based information display were reduced for LL subjects. → Design concerns discovered can be applied to practical use of mobile maintenance aids. - Abstract: Recently, the importance of effective maintenance in nuclear power plants (NPPs) has been emphasized and research into effective maintenance by adopting mobile maintenance aids (MMAs) have been attempted. For improved and effective use of an MMA display design method based on the hierarchy is proposed and its design considerations are discussed in this study. Six levels of hierarchy are proposed in this paper to classify the maintenance information. By classifying and organizing maintenance information using the hierarchy, maintenance information can be used effectively by users with either high or low levels of expertise. When information classification has been finished, the information for MMA design is selected and designed. With the considerations of MMA design analysis and guidelines, a hierarchy-based MMA is designed for the maintenance tasks. An experiment is conducted using the hierarchy-based MMA in order to estimate the effectiveness of the proposed method for the maintenance tasks and to identify design considerations to enhance the proposed MMAs. The result indicated that a hierarchy-based manual was more effective than a conventional manual in terms of task completion time and number of errors. The workload for the hierarchy-based manual was estimated less than the conventional manual for subjects with low level of expertise. As the level of expertise increases, subjects tended to follow more abstract information while the number of navigations decreased. It is believed that when mobile devices become pervasive in NPP maintenance fields, the hierarchy model applied MMAs can be used as an effective maintenance supporting tool.

Methadone maintenance therapy as evidence based drug abuse ...

African Journals Online (AJOL)

Methadone maintenance therapy as evidence based drug abuse planning in ... drugs are being used as artificial problem-solvers such as frustrations, stress or ... Drug use is a problem to users when it begins to cause some damage to their ...

Reliability-based maintenance evaluations and standard preventive maintenance programs

International Nuclear Information System (INIS)

Varno, M.; McKinley, M.

1993-01-01

Due to recent issuance of 10CFR50.65, the U.S. Nuclear Regulatory Commission maintenance rule (Rule), and the open-quotes Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plantsclose quotes prepared by the Nuclear Management and Resources Council, many utilities are undertaking review or evaluation of current preventive maintenance (PM) programs. Although PM optimization and documentation are not specifically required by the Rule, an appropriate and effective PM program (PMP) will be the cornerstone of the successful and cost-effective implementation of the Rule. Currently, a project is being conducted at the Vermont Yankee Nuclear Power Station (VYNPS) in conjunction with Quadrex Energy Services to evaluate, optimize, and document the PMP. The project began in March 1993 and is scheduled for completion in mid-1995. The initial scope for the project is the evaluation of those structures, systems, and components that are within the scope of the Rule. Because of the number of systems to be evaluated (∼50), the desired completion schedule, and cost considerations, a streamlined approach to PM optimization and documentation is being utilized

Azithromycin maintenance therapy in patients with cystic fibrosis : A dose advice based on a review of pharmacokinetics, efficacy, and side effects

NARCIS (Netherlands)

Wilms, Erik B.; Touw, Daniel J.; Heijerman, Harry G.M.; Van Der Ent, Cornelis K.

Azithromycin maintenance therapy results in improvement of respiratory function in patients with cystic fibrosis (CF). In azithromycin maintenance therapy, several dosing schemes are applied. In this review, we combine current knowledge about azithromycin pharmacokinetics with the dosing schedules

A condition-based maintenance policy for multi-component systems with a high maintenance setup cost

NARCIS (Netherlands)

Zhu, Q.; Peng, H.; Houtum, van G.J.J.A.N.

2012-01-01

Condition-based maintenance (CBM) is becoming increasingly important due to the development of advanced sensor and ICT technology, so that the condition data can be collected remotely. We propose a new CBM policy for multi-component systems with continuous stochastic deteriorations. To reduce the

Risk-Based Maintenance Assessment in the Manufacturing Industry: Minimisation of Suboptimal Prioritisation

Directory of Open Access Journals (Sweden)

Ratnayake R.M. Chandima

2017-03-01

Full Text Available Manufacturing firms continuously strive to increase the efficiency and effectiveness in the maintenance management processes. Focus is placed on eliminating the unexpected failures which cause unnecessary costs and the production losses. Risk-based maintenance (RBM strategies enable to address the above through the identification of probability and consequences of potential failures whilst providing a way for prioritisation of maintenance actions based on the risk of possible failures. Such prioritisations enable to identify the optimal maintenance strategy, intervals of maintenance tasks, and optimal level of spare parts inventory. However, the risk assessment activities are performed with the support of a risk matrix. Suboptimal classifications and/or prioritisations arise due to the inherent nature of the risk matrix. This is caused by the fact that there are no means to incorporate actual circumstances at the boundary of the input ranges or at the levels of linguistic data and risk categories. In this paper, a risk matrix is first developed in collaboration with one of the manufacturing firms in Poland. Then, it illustrates the use of fuzzy logic for minimisation of suboptimal prioritisation and/or classifications using a fuzzy inference system (FIS together with illustrative membership functions and a rule base. Finally, an illustrative risk assessment is also demonstrated to illustrate the methodology.

Prioritization of pavement maintenance sections using objective based Analytic Hierarchy Process

Directory of Open Access Journals (Sweden)

Sarfaraz Ahmed

2017-03-01

Full Text Available The application of Analytic Hierarchy Process (AHP method for the prioritization of pavement maintenance sections is widespread now-a-days. Although the evaluation of pavement maintenance section through AHP method is simple, where the relative importance (on Saaty’s scale assigned to each parameter in the hierarchy varies between the experts (transportation professionals consulted, which leads to discrepancies in the final rankings of the sections’, due to the subjectivity in the process. Further, experts base their decisions solely on their experience while consideration is not given to the actual quantitative physical condition of the roads. To overcome these difficulties an objective based AHP method is proposed in this study, where pairwise comparison values are assigned based on the collected field data from a road network in Mumbai city, consisting of 28 road sections. The final ranking list of candidate sections takes into consideration the priority weight of alternatives, which reflect the road conditions. The solution of priority ratings of AHP method is compared with the corresponding solution of road condition index method, a traditional pavement maintenance procedure. The findings of the present study suggest that objective based AHP method is more suitable for the prioritization of pavement maintenance of roads. Keywords: Prioritization, Analytic Hierarchy Process, Road condition index, Objective method, Rating and ranking

Analysis of the possibility of applying a condition-based maintenance model on an example of tank weapons

Directory of Open Access Journals (Sweden)

Igor J. Epler

2013-12-01

Full Text Available For any modern army it is very important to continuously maintain a high degree of operational (combat readiness (availability in order to maximize the effectiveness of the use of technical systems. Since determination and prediction of technical states and failures of technical systems in engineering, especially in armament, are difficult due to the impossibility of continuous condition monitoring with appropriate measuring equipment there is a need for a maintenance model that would be most helpful in taking timely action maintenance. In this paper, the subject of research is a model of maintenance of the M-84 tank  weapoons systems.   IntroductionThe M-84 tank is one of the most promising technical systems in the Serbian Army. Its use and modifications are foreseen in the next ten years. The  M-84 is characterized by good tactical and technical characteristics. It has a powerful 125 mm cannon, coupled 7.62 mm machine gun and 12.7 mm anti-aircraft machine gun. The M-84 tank has an automatic battery charger and a fire control system. The fire control system enables fast target tracking and stabilization of the cannon barrel, which is a prerequisite for timely and favorable effect on the target. There are certain ambiguities in the existing model of maintenance of tank weapons.   Technical diagnostics Technical diagnostics, as a part of the process of condition-based maintenance, should determine technical conditions of components or technical systems with certain accuracy at a point in time.   Maintenance strategy A maintenance strategy can be defined as a variant of a maintenance system determined by a concept, organization and character of maintenance procedures, as well as the relationship between the various levels at which maintenance is performed. It is defined for technical system parts, individual technical systems and for system maintenance as a whole. The basic maintenance strategies implemented today are: -      corrective

Managed maintenance, the next step in power plant maintenance

International Nuclear Information System (INIS)

Butterworth, G.; Anderson, T.M.

1984-01-01

The Westinghouse Nuclear Services Integration Division managed maintenance services are described. Essential to the management and control of a total plant maintenance programme is the development of a comprehensive maintenance specification. During recent years Westinghouse has jointly developed total plant engineering-based maintenance specifications with a number of utilities. The process employed and the experience to date are described. To efficiently implement the maintenance programme Westinghouse has developed a computer software program specifically designed for day to day use at the power plant by maintenance personnel. This program retains an equipment maintenance history, schedules maintenance activities, issues work orders and performs a number of sophisticated analyses of the maintenance backlog and forecast, equipment failure rates, etc. The functions of this software program are described and details of Westinghouse efforts to support the utilities in reducing outage times through development of predefined outage plans for critical report maintenance activities are given. Also described is the experience gained in the training of specialized maintenance personnel, employing competency-based training techniques and equipment mock-ups, and the benefits experienced, in terms of improved quality and productivity of maintenance performed. The success experienced with these methods has caused Westinghouse to expand the use of these training techniques to the more routine skill areas of power plant maintenance. A significant reduction in the operating costs of nuclear power plants will only be brought about by a significant improvement in the quality of maintenance. Westinghouse intends to effect this change by expanding its international service capabilities and to make major investments in order to promote technological developments in the area of power plant maintenance. (author)

Knowledge base verification based on enhanced colored petri net

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1998-12-31

Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

Knowledge base verification based on enhanced colored petri net

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1997-12-31

Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

Distributed, cooperating knowledge-based systems

Science.gov (United States)

Truszkowski, Walt

1991-01-01

Some current research in the development and application of distributed, cooperating knowledge-based systems technology is addressed. The focus of the current research is the spacecraft ground operations environment. The underlying hypothesis is that, because of the increasing size, complexity, and cost of planned systems, conventional procedural approaches to the architecture of automated systems will give way to a more comprehensive knowledge-based approach. A hallmark of these future systems will be the integration of multiple knowledge-based agents which understand the operational goals of the system and cooperate with each other and the humans in the loop to attain the goals. The current work includes the development of a reference model for knowledge-base management, the development of a formal model of cooperating knowledge-based agents, the use of testbed for prototyping and evaluating various knowledge-based concepts, and beginning work on the establishment of an object-oriented model of an intelligent end-to-end (spacecraft to user) system. An introductory discussion of these activities is presented, the major concepts and principles being investigated are highlighted, and their potential use in other application domains is indicated.

Preventive Maintenance Interval Prediction: a Spare Parts Inventory Cost and Lost Earning Based Model

Directory of Open Access Journals (Sweden)

O. A. Adebimpe

2015-06-01

Full Text Available In this paper, some preventive maintenance parameters in manufacturing firms were identified and used to develop cost based functions in terms of machine preventive maintenance. The proposed cost based model considers system’s reliability, cost of keeping spare parts inventory and lost earnings in deriving optimal maintenance interval. A case of a manufacturing firm in Nigeria was observed and the data was used to evaluate the model.

Laser-Based Maintenance and Repair Technologies for Reactor Components

International Nuclear Information System (INIS)

Masaki Yoda; Naruhiko Mukai; Makoto Ochiai; Masataka Tamura; Satoshi Okada; Katsuhiko Sato; Motohiko Kimura; Yuji Sano; Noboru Saito; Seishi Shima; Tetsuo Yamamoto

2004-01-01

Toshiba has developed various laser-based maintenance and repair technologies and applied them to existing nuclear power plants. Laser-based technology is considered to be the best tool for remote processing in nuclear power plants, and particularly so for the maintenance and repair of reactor core components. Accessibility could be drastically improved by a simple handling system owing to the absence of reactive force against laser irradiation and the flexible optical fiber. For the preventive maintenance, laser peening (LP) technology was developed and applied to reactor components in operating BWR plants. LP is a novel process to improve residual stress from tensile to compressive on material surface layer by irradiating focused high-power laser pulses in water. We have developed a fiber-delivered LP system as a preventive maintenance measure against stress corrosion cracking (SCC). Laser ultrasonic testing (LUT) has a great potential to be applied to the remote inspection of reactor components. Laser-induced surface acoustic wave (SAW) inspection system was developed using a compact probe with a multi-mode optical fiber and an interferometer. The developed system successfully detected a micro slit of 0.5 mm depth on weld metal and heat-affected zone (HAZ). An artificial SCC was also detected by the system. We are developing a new LP system combined with LUT to treat the inner surface of bottom-mounted instruments (BMI) of PWR plants. Underwater laser seal welding (LSW) technology was also developed to apply surface crack. LSW is expected to isolate the crack tip from corrosive water environment and to stop the propagation of the crack. Rapid heating and cooling of the process minimize the heat effect, which extends the applicability to neutron-irradiated material. This paper describes recent advances in the development and application of such laser-based technologies. (authors)

Risk-Based Operation and Maintenance Using Bayesian Networks

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2011-01-01

This paper describes how risk-based decision making can be used for maintenance planning of components exposed to degradation such as fatigue in offshore wind turbines. In fatigue models, large epistemic uncertainties are usually present. These can be reduced if monitoring results are used to upd...

Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud; Sørensen, John Dalsgaard

2018-01-01

The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...... monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution...

Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud; Sørensen, John Dalsgaard

2018-01-01

monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud

2017-01-01

monitoring, fault detection and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

Remediation of Gremikha Coastal maintenance base - status of the project

International Nuclear Information System (INIS)

Pillette-Cousin, L.; Stepennov, B.S.; Gorbatchev, A.

2008-01-01

The former coastal maintenance base in Gremikha is located in the Kola Peninsula, along the Barents Sea, about 300 km east from Murmansk. There is no road or railway to get there, therefore the only possible connection is either by sea or by helicopter. Remediation of the Gremikha coastal maintenance base (CMB) is now one of the main priorities for Rosatom (the Agency for Atomic Energy of the Russian Federation) because nuclear and radioactive waste are currently stored in conditions which do not meet the up-to-date safety and regulatory requirements and it might represent an environmental hazard and a risk of misappropriation of the nuclear material stored there. (authors)

Knowledge Pipeline: A Task Oriented Way to Implement Knowledge Management

International Nuclear Information System (INIS)

Pan Jiajie

2014-01-01

Concept of knowledge pipeline: There are many pipelines named by tasks or business processes in an organization. Knowledge contributors put knowledge to its corresponding pipelines. A maintenance team could keep the knowledge in pipelines clear and valid. Users could get knowledge just like opening a faucet in terms of their tasks or business processes

Framework for implementation of maintenance management in distribution network service providers

International Nuclear Information System (INIS)

Gomez Fernandez, Juan Francisco; Crespo Marquez, Adolfo

2009-01-01

Distribution network service providers (DNSP) are companies dealing with network infrastructure, such as distribution of gas, water, electricity or telecommunications, and they require the development of special maintenance management (MM) capabilities in order to satisfy the needs of their customers. In this sector, maintenance management information systems are essential to ensure control, gain knowledge and improve decision making. The aim of this paper is the study of specific characteristics of maintenance in these types of companies. We will investigate existing standards and best management practices with the scope of defining a suitable ad-hoc framework for implementation of maintenance management. The conclusion of the work supports the proposition of a framework consisting on a processes framework based on a structure of systems, integrated for continuous improvement of maintenance activities. The paper offers a very practical approach to the problem, as a result of more of 10 years of professional experience within this sector, and specially focused to network maintenance.

Community-based knowledge translation: unexplored opportunities

Directory of Open Access Journals (Sweden)

Armstrong Rebecca

2011-06-01

Full Text Available Abstract Background Knowledge translation is an interactive process of knowledge exchange between health researchers and knowledge users. Given that the health system is broad in scope, it is important to reflect on how definitions and applications of knowledge translation might differ by setting and focus. Community-based organizations and their practitioners share common characteristics related to their setting, the evidence used in this setting, and anticipated outcomes that are not, in our experience, satisfactorily reflected in current knowledge translation approaches, frameworks, or tools. Discussion Community-based organizations face a distinctive set of challenges and concerns related to engaging in the knowledge translation process, suggesting a unique perspective on knowledge translation in these settings. Specifically, community-based organizations tend to value the process of working in collaboration with multi-sector stakeholders in order to achieve an outcome. A feature of such community-based collaborations is the way in which 'evidence' is conceptualized or defined by these partners, which may in turn influence the degree to which generalizable research evidence in particular is relevant and useful when balanced against more contextually-informed knowledge, such as tacit knowledge. Related to the issues of evidence and context is the desire for local information. For knowledge translation researchers, developing processes to assist community-based organizations to adapt research findings to local circumstances may be the most helpful way to advance decision making in this area. A final characteristic shared by community-based organizations is involvement in advocacy activities, a function that has been virtually ignored in traditional knowledge translation approaches. Summary This commentary is intended to stimulate further discussion in the area of community-based knowledge translation. Knowledge translation, and exchange

Machine intelligence and knowledge bases

Energy Technology Data Exchange (ETDEWEB)

Furukawa, K

1981-09-01

The basic functions necessary in machine intelligence are a knowledge base and a logic programming language such as PROLOG using deductive reasoning. Recently inductive reasoning based on meta knowledge and default reasoning have been developed. The creative thought model of Lenit is reviewed and the concept of knowledge engineering is introduced. 17 references.

A preventive maintenance policy based on dependent two-stage deterioration and external shocks

International Nuclear Information System (INIS)

Yang, Li; Ma, Xiaobing; Peng, Rui; Zhai, Qingqing; Zhao, Yu

2017-01-01

This paper proposes a preventive maintenance policy for a single-unit system whose failure has two competing and dependent causes, i.e., internal deterioration and sudden shocks. The internal failure process is divided into two stages, i.e. normal and defective. Shocks arrive according to a non-homogeneous Poisson process (NHPP), leading to the failure of the system immediately. The occurrence rate of a shock is affected by the state of the system. Both an age-based replacement and finite number of periodic inspections are schemed simultaneously to deal with the competing failures. The objective of this study is to determine the optimal preventive replacement interval, inspection interval and number of inspections such that the expected cost per unit time is minimized. A case study on oil pipeline maintenance is presented to illustrate the maintenance policy. - Highlights: • A maintenance model based on two-stage deterioration and sudden shocks is developed. • The impact of internal system state on external shock process is studied. • A new preventive maintenance strategy combining age-based replacements and periodic inspections is proposed. • Postponed replacement of a defective system is provided by restricting the number of inspections.

Nonstructural urban stormwater quality measures: building a knowledge base to improve their use.

Science.gov (United States)

Taylor, André C; Fletcher, Tim D

2007-05-01

This article summarizes a research project that investigated the use, performance, cost, and evaluation of nonstructural measures to improve urban stormwater quality. A survey of urban stormwater managers from Australia, New Zealand, and the United States revealed a widespread trend of increasing use of nonstructural measures among leading stormwater management agencies, with at least 76% of 41 types of nonstructural measures being found to be increasing in use. Data gathered from the survey, an international literature review, and a multicriteria analysis highlighted four nonstructural measures of greatest potential value: mandatory town planning controls that promote the adoption of low-impact development principles and techniques; development of strategic urban stormwater management plans for a city, shire, or catchment; stormwater management measures and programs for construction/building sites; and stormwater management activities related to municipal maintenance operations such as maintenance of the stormwater drainage network and manual litter collections. Knowledge gained on the use and performance of nonstructural measures from the survey, literature review, and three trial evaluation projects was used to develop tailored monitoring and evaluation guidelines for these types of measure. These guidelines incorporate a new evaluation framework based on seven alternative styles of evaluation that range from simply monitoring whether a nonstructural measure has been fully implemented to monitoring its impact on waterway health. This research helps to build the stormwater management industry's knowledge base concerning nonstructural measures and provides a practical tool to address common impediments associated with monitoring and evaluating the performance and cost of these measures.

Reflection of centrifugal pumps maintenance

International Nuclear Information System (INIS)

Mozos Fernandez, V.

2010-01-01

The aim of this work is to prove that is not necessary a deep and complex knowledge to manage the centrifugal pumps maintenance. According to the author, only deep but single technical knowledge about causes of breakdowns in the different and simple component parts of the pumps, are required. (Author)

The challenges of maintaining indigenous ecological knowledge

Directory of Open Access Journals (Sweden)

Joe McCarter

2014-09-01

Full Text Available Increased interest in indigenous ecological knowledge (IEK has led to concern that it is vulnerable amidst social and ecological change. In response, multiple authors have recommended the establishment of programs for the maintenance and revitalization of IEK systems. However, few studies have analyzed the methods, opportunities, and challenges of these programs. This is a critical gap, as IEK maintenance is challenging and will require layered and evidence-based solutions. We seek to build a foundation for future approaches to IEK maintenance. First, we present a systematic literature review of IEK maintenance programs (n = 39 and discuss the opportunities and challenges inherent in five broad groups of published approaches. Second, we use two case studies from the Republic of Vanuatu to illustrate these challenges in more depth. The first case study takes a community-based approach, which has inherent strengths (e.g., localized organization. It has, however, faced practical (e.g., funding and epistemological (changing modes of knowledge transmission challenges. The second case study seeks to facilitate IEK transmission within the formal school system. Although this model has potential, it has faced significant challenges (e.g., lack of institutional linkages. We conclude that supporting and strengthening IEK is important but that serious attention is needed to account for the social, situated, and dynamic nature of IEK. In closing, we use the review and case studies to propose four principles that may guide adaptive and flexible approaches for the future maintenance of IEK systems.

The Expert System For Safety Assesment Of Kartini Reactor Operation And Maintenance

International Nuclear Information System (INIS)

Syarip

2000-01-01

An expert system for safety assessment of Kartini reactor operation and maintenance based on fuzzy logic method has been made. The expert system is developed from the Fuzzy Expert System Tools (FEST), i.e. by developing the knowledge base and data base files of Kartini research reactor system and operations with an inference engine based on FEST. The knowledge base is represented in the procedural knowledge as heuristic rules or generally known as rule-base in the from of If-then rule. The fuzzy inference process and the conclusion of the rule is done by FEST based on direct chaining method with interactive as well as non-interactive modes. The safety assessment of Kartini reactor based on this method gives more realistic value than the conventional method or binary logic

A condition-based maintenance policy for multi-component systems with Lévy copulas dependence

International Nuclear Information System (INIS)

Li, Heping; Deloux, Estelle; Dieulle, Laurence

2016-01-01

In this paper, we propose a new condition-based maintenance policy for multi-component systems taking into account stochastic and economic dependences. The stochastic dependence between components due to common environment is modelled by Lévy copulas. Its influence on the maintenance optimization is investigated with different dependence degrees. On the issue of economic dependence providing opportunities to group maintenance activities, a new maintenance decision rule is proposed which permits maintenance grouping. In order to evaluate the performance of the proposed maintenance policy, we compare it to the classical maintenance policies. - Highlights: • A new adaptive maintenance policy for grouping maintenance actions is proposed. • The impacts of both economic and stochastic dependences are investigated. • The performance of the proposed maintenance policy is evaluated under different system configurations. • The stochastic dependence is modelled by Lévy copulas. • The proposed maintenance decision rule can take full advantage of economic and stochastic dependences.

Performance based regulation - The maintenance rule

Energy Technology Data Exchange (ETDEWEB)

Correia, Richard P. [NRR/DOTS/TQMP, U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, M/S OWFN 10A19, Washington, D.C. 20555 (United States)

1997-07-01

The U.S. Nuclear Regulatory Commission has begun a transition from 'process-oriented' to 'results-oriented' regulations. The maintenance rule is a results-oriented rule that mandates consideration of risk and plant performance. The Maintenance Rule allows licensees to devise the most effective and efficient means of achieving the results described in the rule including the use of Probabilistic Risk (or Safety) Assessments. The NRC staff conducted a series of site visits to evaluate implementation of the Rule. Conclusions from the site visits indicated that the results-oriented Maintenance Rule can be successfully implemented and enforced. (author)

Performance based regulation - The maintenance rule

International Nuclear Information System (INIS)

Correia, Richard P.

1997-01-01

The U.S. Nuclear Regulatory Commission has begun a transition from 'process-oriented' to 'results-oriented' regulations. The maintenance rule is a results-oriented rule that mandates consideration of risk and plant performance. The Maintenance Rule allows licensees to devise the most effective and efficient means of achieving the results described in the rule including the use of Probabilistic Risk (or Safety) Assessments. The NRC staff conducted a series of site visits to evaluate implementation of the Rule. Conclusions from the site visits indicated that the results-oriented Maintenance Rule can be successfully implemented and enforced. (author)

Corrosion Sensor Development for Condition-Based Maintenance of Aircraft

Directory of Open Access Journals (Sweden)

Gino Rinaldi

2012-01-01

Full Text Available Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be present in all of that type of aircraft. This safety protocol and its associated unscheduled maintenance requirement drive up the operational costs of the fleet and limit the availability of the aircraft. Hence, there is an opportunity at present for developing novel sensing technologies and schemes to aid in shifting time-based maintenance schedules towards condition-based maintenance procedures. In this work, part of the ongoing development of a multiparameter integrated corrosion sensor is presented. It consists of carbon nanotube/polyaniline polymer sensors and commercial-off-the-shelf sensors. It is being developed primarily for monitoring environmental and material factors for the purpose of providing a means to more accurately assess the structural integrity of aerospace aluminium alloys through fusion of multiparameter sensor data. Preliminary experimental test results are presented for chloride ion concentration, hydrogen gas evolution, humidity variations, and material degradation.

A review of e-maintenance capabilities and challenges

OpenAIRE

Adolfo Crespo Marquez; Benoit Iung

2008-01-01

Within the era of e-manufacturing and e-business, e-maintenance provides the opportunity for a new maintenance generation. E-maintenance integrates existing telemaintenance principles, with web-services and modern e-collaboration principles. Collaboration allows not only to share and exchange information but also knowledge and (e)-intelligence. This paper outlines the basic capabilities provided by e-maintenance to companies as well as describes emerging challenges to benefit from these new o...

Knowledge Based Economy Assessment

OpenAIRE

Madalina Cristina Tocan

2012-01-01

The importance of knowledge-based economy (KBE) in the XXI century is evident. In the article the reflection of knowledge on economy is analyzed. The main point is targeted to the analysis of characteristics of knowledge expression in economy and to the construction of structure of KBE expression. This allows understanding the mechanism of functioning of knowledge economy. The authors highlight the possibility to assess the penetration level of KBE which could manifest itself trough the exist...

Two Innovative Steps for Training on Maintenance: 'VIRMAN' Spanish Project based on Virtual Reality 'STARMATE' European Project based on Augmented Reality

International Nuclear Information System (INIS)

Gonzalez Anez, Francisco

2002-01-01

This paper presents two development projects (STARMATE and VIRMAN) focused on supporting training on maintenance. Both projects aim at specifying, designing, developing, and demonstrating prototypes allowing computer guided maintenance of complex mechanical elements using Augmented and Virtual Reality techniques. VIRMAN is a Spanish development project. The objective is to create a computer tool for maintenance training course elaborations and training delivery based on 3D virtual reality models of complex components. The training delivery includes 3D record displays on maintenance procedures with all complementary information for intervention understanding. Users are requested to perform the maintenance intervention trying to follow up the procedure. Users can be evaluated about the level of knowledge achieved. Instructors can check the evaluation records left during the training sessions. VIRMAN is simple software supported by a regular computer and can be used in an Internet framework. STARMATE is a forward step in the area of virtual reality. STARMATE is a European Commission project in the frame of 'Information Societies Technologies'. A consortium of five companies and one research institute shares their expertise in this new technology. STARMATE provides two main functionalities (1) user assistance for achieving assembly/de-assembly and following maintenance procedures, and (2) workforce training. The project relies on Augmented Reality techniques, which is a growing area in Virtual Reality research. The idea of Augmented Reality is to combine a real scene, viewed by the user, with a virtual scene, generated by a computer, augmenting the reality with additional information. The user interface is see-through goggles, headphones, microphone and an optical tracking system. All these devices are integrated in a helmet connected with two regular computers. The user has his hands free for performing the maintenance intervention and he can navigate in the virtual

Maintenance management of railway infrastructures based on reliability analysis

International Nuclear Information System (INIS)

Macchi, Marco; Garetti, Marco; Centrone, Domenico; Fumagalli, Luca; Piero Pavirani, Gian

2012-01-01

Railway infrastructure maintenance plays a crucial role for rail transport. It aims at guaranteeing safety of operations and availability of railway tracks and related equipment for traffic regulation. Moreover, it is one major cost for rail transport operations. Thus, the increased competition in traffic market is asking for maintenance improvement, aiming at the reduction of maintenance expenditures while keeping the safety of operations. This issue is addressed by the methodology presented in the paper. The first step of the methodology consists of a family-based approach for the equipment reliability analysis; its purpose is the identification of families of railway items which can be given the same reliability targets. The second step builds the reliability model of the railway system for identifying the most critical items, given a required service level for the transportation system. The two methods have been implemented and tested in practical case studies, in the context of Rete Ferroviaria Italiana, the Italian public limited company for railway transportation.

14 CFR 119.47 - Maintaining a principal base of operations, main operations base, and main maintenance base...

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintaining a principal base of operations, main operations base, and main maintenance base; change of address. 119.47 Section 119.47 Aeronautics... Under Part 121 or Part 135 of This Chapter § 119.47 Maintaining a principal base of operations, main...

Knowledge Base Editor (SharpKBE)

Science.gov (United States)

Tikidjian, Raffi; James, Mark; Mackey, Ryan

2007-01-01

The SharpKBE software provides a graphical user interface environment for domain experts to build and manage knowledge base systems. Knowledge bases can be exported/translated to various target languages automatically, including customizable target languages.

Understanding images using knowledge based approach

International Nuclear Information System (INIS)

Tascini, G.

1985-01-01

This paper presents an approach to image understanding focusing on low level image processing and proposes a rule-based approach as part of larger knowledge-based system. The general system has a yerarchical structure that comprises several knowledge-based layers. The main idea is to confine at the lower level the domain independent knowledge and to reserve the higher levels for the domain dependent knowledge, that is for the interpretation

Optimizing Maintenance of Constraint-Based Database Caches

Science.gov (United States)

Klein, Joachim; Braun, Susanne

Caching data reduces user-perceived latency and often enhances availability in case of server crashes or network failures. DB caching aims at local processing of declarative queries in a DBMS-managed cache close to the application. Query evaluation must produce the same results as if done at the remote database backend, which implies that all data records needed to process such a query must be present and controlled by the cache, i. e., to achieve “predicate-specific” loading and unloading of such record sets. Hence, cache maintenance must be based on cache constraints such that “predicate completeness” of the caching units currently present can be guaranteed at any point in time. We explore how cache groups can be maintained to provide the data currently needed. Moreover, we design and optimize loading and unloading algorithms for sets of records keeping the caching units complete, before we empirically identify the costs involved in cache maintenance.

Joint optimization of condition-based maintenance and production lot-sizing

NARCIS (Netherlands)

Peng, H.; van Houtum, G.J.J.A.N.

2016-01-01

Due to the development of sensor technologies nowadays, condition-based maintenance (CBM) programs can be established and optimized based on the data collected through condition monitoring. The CBM activities can significantly increase the uptime of a machine. However, they should be conducted in a

Managing wind turbine reliability and maintenance via performance-based contract

DEFF Research Database (Denmark)

Jin, Tongdan; Ding, Yi; Guo, Huairui

2012-01-01

between system cost, reliability and spare parts stocking. This analytical insight into the system performance allows the turbine manufacturer to optimize design, production, and after-sales services. The study aims to create a theoretical basis to facilitate the transition of the maintenance paradigm......Performance-based contracting (PBC) is reshaping the acquisition, operation, and maintenance of capital equipment. Under the PBC scheme, we propose a holistic approach for lowering the cost of wind turbine ownership while meeting the availability requirement. Our effects are focused on integrated...... firms who design and market wind turbines, and also provide maintenance and repair service. PBC differs from conventional service contracts in that the wind farmers compensate the service provider for the system performance, not the spare parts and repair labor. We explore the analytical relationship...

Analyzing maintenance strategies by agent-based simulations: A feasibility study

International Nuclear Information System (INIS)

Kaegi, M.; Mock, R.; Kroeger, W.

2009-01-01

Thoroughly planned and implemented maintenance strategies save time and cost. However, the integration of maintenance work into reliability analysis is difficult as common modeling techniques are often not applicable due to state explosion which calls for restrictive model assumptions and oversimplification. From authors' point of view, agent-based modeling (ABM) of technical and organizational systems is a promising approach to overcome such problems. But since ABM is not well established in reliability analysis its feasibility in this area still has to be demonstrated. For this purpose ABM is compared with Markov chains, namely by analyzing the reliability of a maintained n-unit system with dependent repair events, applying both modeling approaches. Although ABM and Markov chains lead to the same numerical results, the former points out the potentiality of an improved system state handling. This is demonstrated by extending the ABM with operators as additional 'agents' featuring their location (x;y) availability (0;1) and different maintenance strategies. This extension highlights the capability of ABM to analyze complex emergent system behavior and allows a systematic refinement and optimization of the maintenance strategies.

Risk Based Maintenance of Offshore Wind Turbines Using Bayesian Networks

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2010-01-01

This paper presents how Bayesian networks can be used to make optimal decisions for repairs of offshore wind turbines. The Bayesian network is an efficient tool for updating a deterioration model whenever new information becomes available from inspections/monitoring. The optimal decision is found...... such that the preventive maintenance effort is balanced against the costs to corrective maintenance including indirect costs to reduced production. The basis for the optimization is the risk based Bayesian decision theory. The method is demonstrated through an application example....

A review of e-maintenance capabilities and challenges

Directory of Open Access Journals (Sweden)

Adolfo Crespo Marquez

2008-02-01

Full Text Available Within the era of e-manufacturing and e-business, e-maintenance provides the opportunity for a new maintenance generation. E-maintenance integrates existing telemaintenance principles, with web-services and modern e-collaboration principles. Collaboration allows not only to share and exchange information but also knowledge and (e-intelligence. This paper outlines the basic capabilities provided by e-maintenance to companies as well as describes emerging challenges to benefit from these new operational improvement opportunities

CRC-cards to support development and maintenance of product configuration systems

DEFF Research Database (Denmark)

Haug, Anders; Hvam, Lars

2009-01-01

This article presents a new definition of special Class, Responsibility and Collaboration (CRC) cards to be used for the development and maintenance of Product Configuration Systems (PCSs). CRC cards were introduced as an informal and user-friendly technique for teaching object-oriented modelling...... and maintenance of PCSs. This procedure has since been applied in several configuration projects and further developed at the Centre for Product Modelling (CPM) at the Technical University of Denmark. However, the investigations of two companies that applies CRC cards to document the knowledge base of their PCSs...

TRIZ method application for improving the special vehicles maintenance

Directory of Open Access Journals (Sweden)

Petrović Saša

2014-01-01

Full Text Available TRIZ methodology provides an opportunity for improving the classical engineering approach based on personal knowledge and experience. This paper presents the application of TRIZ methods for improving vehicle maintenance where special equipment is installed. A specific problem is the maintenance of the periscopes with heating system. Protective glass panels with heating system are rectangular glass elements. Their purpose is to perform mechanical protection of built-in prisms and provide heating of the prisms. Aging and long-term use leads to failure of these elements. The practice requires solutions in order to extend the lifetime of the system. New solution is evaluated by simulation and experiment.

Knowledge management. Preservation and maintenance of implicit knowledge within a company

International Nuclear Information System (INIS)

Schmidt, Ulrich

2010-01-01

EnBW Energie Baden-Wuerttemberg AG operates in a more and more complex economical and political environment. This fact and ambitious growth targets are the reason for EnBW to activate more intensively hidden potentials of the staff and to strengthen their skills. The ''intellectual capital'' of EnBW becomes a key success factor and active knowledge management will be the key to save the sustainability of the company. For the implementation of knowledge management EnBW uses an integrated approach, which includes a cultural, strategic and operational level. Since 2006 the ''Knowledge Relay'' has been used in the EnBW group with great success. (orig.)

Reusing Design Knowledge Based on Design Cases and Knowledge Map

Science.gov (United States)

Yang, Cheng; Liu, Zheng; Wang, Haobai; Shen, Jiaoqi

2013-01-01

Design knowledge was reused for innovative design work to support designers with product design knowledge and help designers who lack rich experiences to improve their design capacity and efficiency. First, based on the ontological model of product design knowledge constructed by taxonomy, implicit and explicit knowledge was extracted from some…

Automated knowledge-base refinement

Science.gov (United States)

Mooney, Raymond J.

1994-01-01

Over the last several years, we have developed several systems for automatically refining incomplete and incorrect knowledge bases. These systems are given an imperfect rule base and a set of training examples and minimally modify the knowledge base to make it consistent with the examples. One of our most recent systems, FORTE, revises first-order Horn-clause knowledge bases. This system can be viewed as automatically debugging Prolog programs based on examples of correct and incorrect I/O pairs. In fact, we have already used the system to debug simple Prolog programs written by students in a programming language course. FORTE has also been used to automatically induce and revise qualitative models of several continuous dynamic devices from qualitative behavior traces. For example, it has been used to induce and revise a qualitative model of a portion of the Reaction Control System (RCS) of the NASA Space Shuttle. By fitting a correct model of this portion of the RCS to simulated qualitative data from a faulty system, FORTE was also able to correctly diagnose simple faults in this system.

Refining Automatically Extracted Knowledge Bases Using Crowdsourcing.

Science.gov (United States)

Li, Chunhua; Zhao, Pengpeng; Sheng, Victor S; Xian, Xuefeng; Wu, Jian; Cui, Zhiming

2017-01-01

Machine-constructed knowledge bases often contain noisy and inaccurate facts. There exists significant work in developing automated algorithms for knowledge base refinement. Automated approaches improve the quality of knowledge bases but are far from perfect. In this paper, we leverage crowdsourcing to improve the quality of automatically extracted knowledge bases. As human labelling is costly, an important research challenge is how we can use limited human resources to maximize the quality improvement for a knowledge base. To address this problem, we first introduce a concept of semantic constraints that can be used to detect potential errors and do inference among candidate facts. Then, based on semantic constraints, we propose rank-based and graph-based algorithms for crowdsourced knowledge refining, which judiciously select the most beneficial candidate facts to conduct crowdsourcing and prune unnecessary questions. Our experiments show that our method improves the quality of knowledge bases significantly and outperforms state-of-the-art automatic methods under a reasonable crowdsourcing cost.

Refining Automatically Extracted Knowledge Bases Using Crowdsourcing

Directory of Open Access Journals (Sweden)

Chunhua Li

2017-01-01

Full Text Available Machine-constructed knowledge bases often contain noisy and inaccurate facts. There exists significant work in developing automated algorithms for knowledge base refinement. Automated approaches improve the quality of knowledge bases but are far from perfect. In this paper, we leverage crowdsourcing to improve the quality of automatically extracted knowledge bases. As human labelling is costly, an important research challenge is how we can use limited human resources to maximize the quality improvement for a knowledge base. To address this problem, we first introduce a concept of semantic constraints that can be used to detect potential errors and do inference among candidate facts. Then, based on semantic constraints, we propose rank-based and graph-based algorithms for crowdsourced knowledge refining, which judiciously select the most beneficial candidate facts to conduct crowdsourcing and prune unnecessary questions. Our experiments show that our method improves the quality of knowledge bases significantly and outperforms state-of-the-art automatic methods under a reasonable crowdsourcing cost.

A Novel Short-Term Maintenance Strategy for Power Transmission and Transformation Equipment Based on Risk-Cost-Analysis

Directory of Open Access Journals (Sweden)

Hang Yang

2017-11-01

Full Text Available Current studies on preventive condition-based maintenance of power transmission and transformation equipment mainly focus on mid-term or long-term maintenance, and cannot meet the requirements of short-term especially temporary maintenance. In order to solve the defects of the present preventive maintenance strategies, according to the engineering application and based on risk-cost analysis, a short-term maintenance strategy is proposed in this manuscript. For the equipment working in bad health condition, its active maintenance costs and operation risk costs are evaluated, respectively. Then the latest maintenance time is calculated in accordance with the principle that its operation risk costs are no higher than active maintenance costs. Utilizing the latest maintenance time, the best maintenance time is calculated by setting the maximum relative earnings of postponing maintenance as the target, which provides the operation staffs with comprehensive maintenance-decision support. In the end, different cases on the IEEE 24-bus system are simulated. The effectiveness and advantages of the proposed strategy are demonstrated by the simulation results.

The Issues of Track Maintenance Management in Indonesia (Based on Study of the British Railways

Directory of Open Access Journals (Sweden)

Tetria Yunik Dewi Pamungkas

2017-01-01

Full Text Available It is believed that there is merit in researching how the management of track maintenance is organized in the United Kingdom, in particular by Network Rail, and then evaluating how this can be applied to the benefit of Indonesian Railways. The purpose of this research was expected to provide recommendations for management improvement of track maintenance by researching the track maintenance management system in Network Rail. This research study is based on secondary data. The analysis was conducted by using comparison method which compares the British Railways management and Indonesia railway management related to track maintenance management. The track maintenance management system was studied by using Network Rail. The results were compared with track maintenance management system in Indonesia. The comparison will provide the data differences that evaluated so the problem can be identified. The final result of this analysis was the identification of problems and improvisation that can be done for the development of track maintenance management in Indonesia. Several management issues have been mapped to several groups: finance management, structure organization, and asset management. From the problems that have been mapped, some improvements are recommended as monopolist authority restriction, maintenance system contract extension, re-structuring organization hierarchy, business plan consideration, track monitoring strategy arrangement, and condition based maintenance strategy adoption.

Bayesian Based Diagnostic Model for Condition Based Maintenance of Offshore Wind Farms

Directory of Open Access Journals (Sweden)

Masoud Asgarpour

2018-01-01

Full Text Available Operation and maintenance costs are a major contributor to the Levelized Cost of Energy for electricity produced by offshore wind and can be significantly reduced if existing corrective actions are performed as efficiently as possible and if future corrective actions are avoided by performing sufficient preventive actions. This paper presents an applied and generic diagnostic model for fault detection and condition based maintenance of offshore wind components. The diagnostic model is based on two probabilistic matrices; first, a confidence matrix, representing the probability of detection using each fault detection method, and second, a diagnosis matrix, representing the individual outcome of each fault detection method. Once the confidence and diagnosis matrices of a component are defined, the individual diagnoses of each fault detection method are combined into a final verdict on the fault state of that component. Furthermore, this paper introduces a Bayesian updating model based on observations collected by inspections to decrease the uncertainty of initial confidence matrix. The framework and implementation of the presented diagnostic model are further explained within a case study for a wind turbine component based on vibration, temperature, and oil particle fault detection methods. The last part of the paper will have a discussion of the case study results and present conclusions.

XML-Based SHINE Knowledge Base Interchange Language

Science.gov (United States)

James, Mark; Mackey, Ryan; Tikidjian, Raffi

2008-01-01

The SHINE Knowledge Base Interchange Language software has been designed to more efficiently send new knowledge bases to spacecraft that have been embedded with the Spacecraft Health Inference Engine (SHINE) tool. The intention of the behavioral model is to capture most of the information generally associated with a spacecraft functional model, while specifically addressing the needs of execution within SHINE and Livingstone. As such, it has some constructs that are based on one or the other.

Current trends on knowledge-based systems

CERN Document Server

Valencia-García, Rafael

2017-01-01

This book presents innovative and high-quality research on the implementation of conceptual frameworks, strategies, techniques, methodologies, informatics platforms and models for developing advanced knowledge-based systems and their application in different fields, including Agriculture, Education, Automotive, Electrical Industry, Business Services, Food Manufacturing, Energy Services, Medicine and others. Knowledge-based technologies employ artificial intelligence methods to heuristically address problems that cannot be solved by means of formal techniques. These technologies draw on standard and novel approaches from various disciplines within Computer Science, including Knowledge Engineering, Natural Language Processing, Decision Support Systems, Artificial Intelligence, Databases, Software Engineering, etc. As a combination of different fields of Artificial Intelligence, the area of Knowledge-Based Systems applies knowledge representation, case-based reasoning, neural networks, Semantic Web and TICs used...

Condition-based maintenance for complex systems : Coordinating maintenance and logistics planning for the process industries

NARCIS (Netherlands)

Olde Keizer, Minou Catharina Anselma

2016-01-01

Maintenance planning in the process industries is extremely complex for various reasons. Plants often run nonstop, allowing little time for performing preventive maintenance. Failures should be prevented, however, as they can lead to system downtime and high losses of revenue. Corrective maintenance

Case-based reasoning: The marriage of knowledge base and data base

Science.gov (United States)

Pulaski, Kirt; Casadaban, Cyprian

1988-01-01

The coupling of data and knowledge has a synergistic effect when building an intelligent data base. The goal is to integrate the data and knowledge almost to the point of indistinguishability, permitting them to be used interchangeably. Examples given in this paper suggest that Case-Based Reasoning is a more integrated way to link data and knowledge than pure rule-based reasoning.

A fuzzy knowledge based method for maintenance planning in a power system

International Nuclear Information System (INIS)

Sergaki, Amalia; Kalaitzakis, Kostas

2002-01-01

The inspection planning in electric power industry is used to assess the safety and reliability of system components and to increase the ability of failure situation identification before it actually occurs. It reflects the implications of the available information on the operational and maintenance history of the system. The output is a ranked list of components, with the most critical ones at the top, which indicates the selection of the components to be inspected. In this paper, we demonstrate the use of a fuzzy relational database model for manipulating the data required for the criticality component ranking in thermal power systems inspection planning, incorporating criteria concerning aspects of safety and reliability, economy, variable operational conditions and environmental impacts. Often, qualitative thresholds and linguistic terms are used for the component criticality analysis. Fuzzy linguistic terms for criteria definitions along with fuzzy inference mechanisms allow the exploitation of the operators' expertise. The proposed database model ensures the representation and handling of the aforementioned fuzzy information and additionally offers to the user the functionality for specifying the precision degree by which the conditions involved in a query are satisfied. In order to illustrate the behavior of the model, a case study is given using real inspection data

Trends and Perspective in Industrial Maintenance Management

DEFF Research Database (Denmark)

Luxhoj, James T.; Thorsteinsson, Uffe; Riis, Jens Ove

1997-01-01

With increased global competition for manufacturing, many companies are seeking ways to gain competitative advanges with respect to cost, service, quality and on-time deliveries. The role that effective maintenance management plays in contributing to overall organizational productivity has received...... increased attention. Trends and perspective in industrial maintenance are presented. The result of benchmarking studies from Scandinavia and United States are also presented and compared. Case studies that examine maintenance methods, knowledge, organization and information systems in three Danish...

Knowledge about nutrition, eating habits and weight reduction intervention among methadone maintenance treatment patients.

Science.gov (United States)

Sason, Anat; Adelson, Miriam; Herzman-Harari, Sarit; Peles, Einat

2018-03-01

Methadone maintenance treatment (MMT) patients are often under-nourished and overweight. The impact of a nutrition intervention program to improve knowledge about healthy food habits and losing weight was studied. Patients were screened for knowledge about nutrition and body mass index (BMI). Those with a low knowledge score or a BMI ≥26 (n=89) were randomly divided into either intervention (two lectures on healthy nutrition followed by weight monitoring over 6weeks), or controls (weighed at baseline, post-lectures and at study closure). The Yale Food Addiction Scale (YFAS), eating behavior rating, and nutrition knowledge questionnaires were used. Knowledge and food habit scores improved in the intervention group (28.4±4.3, 37.2±3.1, 32.5±3.9 pre-, post- and 6-weeks post-lectures, respectively), with no change in the controls (28.6±3.4, 28.2±4.9, 28.1±5.3, repeated measured p(time)=0.001, p(group)=0.001, p(interaction)=0.001); food habit (intervention: 35.0±7.0, 38.4±5.2, 37.5±5.3, controls: 34.0±6.9, 34.7±6.9, 34.6±7.4, p(time)=0.001, p(group)=0.04, p(interaction)=0.06). BMI scores however did not change and were similar in both groups (p=0.9). Of all patients, 10.1% met the criteria of food addiction according to the YFAS, 40.4% lost weight and 28% gained weight, with no group differences. There were more symptoms of food addiction among the patients who gained weight vs. those who lost weight (3.7±2.0 vs. 2.6±1.8, respectively, p=0.04). We concluded that although weight loss was not observed, intervention is recommended for improving knowledge about nutrition and for fostering healthy eating habits with the aim of reducing diet-related morbidity among all MMT patients. Longitudinal program combined with physical activity is needed to study if may lead to weight loss. Copyright © 2017 Elsevier Inc. All rights reserved.

Earnings with Condition Based Maintenance; Ganhos com manutencao preditiva baseada em dados de processo em tempo real

Energy Technology Data Exchange (ETDEWEB)

Barabas, Elizabeth [Softbrasil Automacao, Sao Paulo, SP (Brazil)

2008-07-01

Keeping active in perfect functioning is essential for any company. Today, the maintenance has been performed in most of the stops for maintenance. In a modern industrial environment, where the systems provide data and process information in real time, it is possible bring the performance of the plant to a optimized level, through the maintenance based on condition of equipment. This work described the earnings with CBM (Condition Based Maintenance)

Validation Of Critical Knowledge-Based Systems

Science.gov (United States)

Duke, Eugene L.

1992-01-01

Report discusses approach to verification and validation of knowledge-based systems. Also known as "expert systems". Concerned mainly with development of methodologies for verification of knowledge-based systems critical to flight-research systems; e.g., fault-tolerant control systems for advanced aircraft. Subject matter also has relevance to knowledge-based systems controlling medical life-support equipment or commuter railroad systems.

Concept design of CFETR superconducting magnet system based on different maintenance ports

International Nuclear Information System (INIS)

Zheng, Jinxing; Liu, Xufeng; Song, Yuntao; Wan, Yuanxi; Li, Jiangang; Wu, Sontao; Wan, Baonian; Ye, Minyou; Wei, Jianghua; Xu, Weiwei; Liu, Sumei; Weng, Peide; Lu, Kun; Luo, Zhengping

2013-01-01

Highlights: • This article discussed the concept design of the magnet system of CFETR based on different maintenance port cases. • The major and minor radius of plasma is 5.7 m and 1.6 m, and the central magnetic field was designed as 4.5/5.0 T. • The different maintenance ports design have little impact on the design of TF and CS coils’ design, but have certain impact on the PF coils’ design. -- Abstract: CFETR which stands for “China Fusion Engineering Test Reactor” is a new tokamak device. Its magnet system includes the Toroidal Field (TF) winding, Center solenoid winding (CS) and Poloidal Field (PF) winding. The main goal of the project is to build a fusion engineering Tokamak reactor with its fusion power is 50–200 MW and should be self-sufficiency by blanket. In order to ensure the maintenance ports design and maintenance method, this article discussed the concept design of the magnet system based on different maintenance port cases. The paper detailed studied the magnet system of CFETR including the electromagnetic analysis and parameters for TF (CS)PF. Besides, the volt-seconds of ohmic field are presented as detailed as possible in this paper. In addition, the calculations and optimizations of equilibrium field which should guarantee the plasma discharge of single null shape is carried out. The design work reported here illustrates that the present maintenance ports will not have a great impact on the design of the magnet system. The concept design of the magnet system can meet the requirement of the physical target

An overview of the recent advances in delay-time-based maintenance modelling

International Nuclear Information System (INIS)

Wang, Wenbin

2012-01-01

Industrial plant maintenance is an area which has enormous potential to be improved. It is also an area attracted significant attention from mathematical modellers because of the random phenomenon of plant failures. This paper reviews the recent advances in delay-time-based maintenance modelling, which is one of the mathematical techniques for optimising inspection planning and related problems. The delay-time is a concept that divides a plant failure process into two stages: from new until the point of an identifiable defect, and then from this point to failure. The first stage is called the normal working stage and the second stage is called the failure delay-time stage. If the distributions of the two stages can be quantified, the relationship between the number of failures and the inspection interval can be readily established. This can then be used for optimizing the inspection interval and other related decision variables. In this review, we pay particular attention to new methodological developments and industrial applications of the delay-time-based models over the last few decades. The use of the delay-time concept and modeling techniques in other areas rather than in maintenance is also reviewed. Future research directions are also highlighted. - Highlights: ► Reviewed the recent advances in delay-time-based maintenance models and applications. ► Compared the delay-time-based models with other models. ► Focused on methodologies and applications. ► Pointed out future research directions.

Risk-based and maintenance systems for steam turbines

International Nuclear Information System (INIS)

Fujiyama, K.; Nagai, S.; Akikuni, Y.; Fujiwara, T.; Furuya, K.; Matsumoto, S.; Takagi, K.; Kawabata, T.

2003-01-01

The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants. (orig.)

IGENPRO knowledge-based operator support system

International Nuclear Information System (INIS)

Morman, J. A.

1998-01-01

Research and development is being performed on the knowledge-based IGENPRO operator support package for plant transient diagnostics and management to provide operator assistance during off-normal plant transient conditions. A generic thermal-hydraulic (T-H) first-principles approach is being implemented using automated reasoning, artificial neural networks and fuzzy logic to produce a generic T-H system-independent/plant-independent package. The IGENPRO package has a modular structure composed of three modules: the transient trend analysis module PROTREN, the process diagnostics module PRODIAG and the process management module PROMANA. Cooperative research and development work has focused on the PRODIAG diagnostic module of the IGENPRO package and the operator training matrix of transients used at the Braidwood Pressurized Water Reactor station. Promising simulator testing results with PRODIAG have been obtained for the Braidwood Chemical and Volume Control System (CVCS), and the Component Cooling Water System. Initial CVCS test results have also been obtained for the PROTREN module. The PROMANA effort also involves the CVCS. Future work will be focused on the long-term, slow and mild degradation transients where diagnoses of incipient T-H component failure prior to forced outage events is required. This will enhance the capability of the IGENPRO system as a predictive maintenance tool for plant staff and operator support

Predictive maintenance: A new approach in maintenance of nuclear power plants

International Nuclear Information System (INIS)

Benvenuto, F.; Ferrari, L.

2005-01-01

The maintenance services for a Nuclear Power Plant are in general aimed at reaching the following goals: - Increase component availability and consequently decrease intervention frequency; - Reduce unexpected costs from unexpected repairs; - Progressively decrease the time of each intervention; - Improve the spare parts supply efficiency; - Improve spare parts and consumable warehouse managing; - Decrease maintenance costs. Most of the currently used maintenance activities refer to run-to-failure or preventive approaches: - Run-to-failure or Corrective Maintenance means that work is only carried out when a component or system is faulty and unable to perform its critical function. Non critical components such as filters or components with spare may be maintained in this way; - Preventive or Scheduled Maintenance involves a regular pre-set schedule programme of maintenance work. Programme outlined by the manufacturer of the component in question based on the design life of the component and based on past experience by operation. One step further than Preventive Maintenance is represented by Predictive Maintenance. Whereas Preventive Maintenance bases its schedules on past performance data, a predictive system acquires condition data from the machine to be maintained whilst the machine is in operation. The information obtained from this analysis indicates the condition in real time, provides a diagnosis of wear and shows any trend towards critical conditions. Predictive maintenance mainly consists of the following interventions: - Lubricant analysis; - Collection / analysis of functional parameters, such as motor absorption, flow rate, pressure, temperature, noise, vibration of rotating equipment, thermal efficiency, etc; - Periodical test of lifting systems; - Other operations to acquire sensitive equipment parameters. Predictive Maintenance can reduce the accidental intervention and extend the components life, and, in the end, is increasing the global availability

An evaluation of the Browns Ferry Nuclear Plant preventive maintenance program based on reliability centered maintenance analysis

International Nuclear Information System (INIS)

McCullough, C.L.; McCullough, C.A.

1989-01-01

Reliability centered maintenance (RCM) techniques were used to support a preventative maintenance (PM) upgrade program (PMUP) performed at TVA Browns Ferry Nuclear Plant (BFNP). The purpose of the RCM analysis was to identify critical equipment based on risk and economic importance and to evaluate the PM activities applicable to that equipment. The analysis may be conveniently divided into three steps, which will be outlined in the Approach section of this paper. The net benefit of the RCM approach was a prioritization of the focus of the PM upgrade program so that plant components receive attention proportional to their importance, and assurance that PM activities properly address the most likely component failure causes

Survey of Operators Knowledge of Operation and Maintenance of ...

African Journals Online (AJOL)

Result showed that the machine failures encountered during operations were as a result of poor management, inadequate maintenance practices, and lack of spare parts, obsoleteness, overloading, careless operations and poor storage of machine after use. Recommendations were therefore given to improve the operation ...

Regulatory Framework for the Maintenance of the Relevant Knowledge in the Atomic Energy Use Sector

International Nuclear Information System (INIS)

Sapozhnikov, A.

2016-01-01

Full text: In accordance with the Atomic Act of the Russian Federation the employees and workers (personnel) of nuclear industry organisations, who occupy certain positions or perform specific activities in the field of atomic energy use can start to fulfil their duties only after getting a special permit issued by the state safety regulatory authority. Rostechnadzor issues permits for the specified kinds of activities to personal of nuclear facilities, organizations engaged in transportation of nuclear and radioactive materials, and enterprises performing physical protection and account of nuclear materials and radioactive substances. To enforce the provisions of the Atomic Act Rostechnadzor has developed a regulatory system (requirements, procedures and methodology) for continued supervision over the maintenance of the required level of knowledge and adequate understanding of the nuclear safety requirements by the nuclear personnel, depending on the nature of their job duties and work in the sphere of nuclear energy use. The report presents a long-term experience of Rostechnadzor in implementing an effective regulatory system for maintaining an adequate level of knowledge and expertise of personnel of nuclear industry organisations and ensuring a competent workforce in the nuclear energy sector. (author

Knowledge model of trainee for training support system of plant operation

Energy Technology Data Exchange (ETDEWEB)

Furuhama, Yutaka; Furuta, Kazuo; Kondo, Shunsuke [Tokyo Univ. (Japan). Faculty of Engineering

1996-10-01

We have already proposed a knowledge model of a trainee, which model consists of two layers: hierarchical function and qualitative structure. We developed a method to generate normative operator knowledge based on this knowledge model structure, and to identify trainee`s intention by means of truth maintenance. The methods were tested by cognitive experiment using a prototype of training support system. (author)

Exchanging Description Logic Knowledge Bases

NARCIS (Netherlands)

Arenas, M.; Botoeva, E.; Calvanese, D.; Ryzhikov, V.; Sherkhonov, E.

2012-01-01

In this paper, we study the problem of exchanging knowledge between a source and a target knowledge base (KB), connected through mappings. Differently from the traditional database exchange setting, which considers only the exchange of data, we are interested in exchanging implicit knowledge. As

Querying Natural Logic Knowledge Bases

DEFF Research Database (Denmark)

Andreasen, Troels; Bulskov, Henrik; Jensen, Per Anker

2017-01-01

This paper describes the principles of a system applying natural logic as a knowledge base language. Natural logics are regimented fragments of natural language employing high level inference rules. We advocate the use of natural logic for knowledge bases dealing with querying of classes...... in ontologies and class-relationships such as are common in life-science descriptions. The paper adopts a version of natural logic with recursive restrictive clauses such as relative clauses and adnominal prepositional phrases. It includes passive as well as active voice sentences. We outline a prototype...... for partial translation of natural language into natural logic, featuring further querying and conceptual path finding in natural logic knowledge bases....

Maintenance of nuclear medicine instruments

Energy Technology Data Exchange (ETDEWEB)

Ambro, P

1993-12-31

Maintenance of instruments is generally of two kinds: (a) corrective maintenance, on a non-scheduled basis, to restore equipment to a functional status by repairs; (b) preventive maintenance, to keep equipment in a specified functional condition by providing systematic inspection, quality control, detection and correction of early malfunctions. Most of the instruments used in nuclear medicine are rather complex systems built from mechanical, electrical and electronic parts. Any one of these components is liable to fail at some time or other. Repair could be done only by a specialist who is able to evaluate the condition of the various parts ranging from cables to connectors, from scintillators to photomultipliers, from microprocessors to microswitches. The knowledge of the intricacies of the various electronic components required for their repairs is quite wide and varied. The electronics industry turns out more and more multi-purpose chips which can carry out the functions of many parts used in the instruments of the earlier generation. This provides protection against unauthorized copying of the circuits but it serves another purpose as well of inhibiting repairs by non-factory personnel. These trends of the instrument design should be taken into consideration when a policy has to be developed for the repairs of the hospital based equipment 1 fig., 1 tab

Maintenance of nuclear medicine instruments

International Nuclear Information System (INIS)

Ambro, P.

1992-01-01

Maintenance of instruments is generally of two kinds: (a) corrective maintenance, on a non-scheduled basis, to restore equipment to a functional status by repairs; (b) preventive maintenance, to keep equipment in a specified functional condition by providing systematic inspection, quality control, detection and correction of early malfunctions. Most of the instruments used in nuclear medicine are rather complex systems built from mechanical, electrical and electronic parts. Any one of these components is liable to fail at some time or other. Repair could be done only by a specialist who is able to evaluate the condition of the various parts ranging from cables to connectors, from scintillators to photomultipliers, from microprocessors to microswitches. The knowledge of the intricacies of the various electronic components required for their repairs is quite wide and varied. The electronics industry turns out more and more multi-purpose chips which can carry out the functions of many parts used in the instruments of the earlier generation. This provides protection against unauthorized copying of the circuits but it serves another purpose as well of inhibiting repairs by non-factory personnel. These trends of the instrument design should be taken into consideration when a policy has to be developed for the repairs of the hospital based equipment

An open-source automated continuous condition-based maintenance platform for commercial buildings

Energy Technology Data Exchange (ETDEWEB)

Katipamula, Srinivas; Gowri, Krishnan; Hernandez, George

2016-09-09

This paper describes one such reference process that can be deployed to provide continuous automated conditioned-based maintenance management for buildings that have BIM, a building automation system (BAS) and a computerized maintenance management software (CMMS) systems. The process can be deployed using an open source transactional network platform, VOLTTRON™, designed for distributed sensing and controls and supports both energy efficiency and grid services.

On the concept of e-maintenance: Review and current research

International Nuclear Information System (INIS)

Muller, Alexandre; Crespo Marquez, Adolfo; Iung, Benoit

2008-01-01

The importance of the maintenance function has increased because of its role in keeping and improving system availability and safety, as well as product quality. To support this role, the development of the communication and information technologies has allowed the emergence of the concept of e-maintenance. Within the era of e-manufacturing and e-business, e-maintenance provides the opportunity for a new maintenance generation. As we will discuss later in this paper, e-maintenance integrates existing telemaintenance principles, with Web services and modern e-collaboration principles. Collaboration allows to share and exchange not only information but also knowledge and (e)-intelligence. By means of a collaborative environment, pertinent knowledge and intelligence become available and usable at the right place and time, in order to facilitate reaching the best maintenance decisions. This paper outlines the basic ideas within the e-maintenance concept and then provides an overview of the current research and challenges in this emerging field. An underlying objective is to identify the industrial/academic actors involved in the technological, organizational or management issues related to the development of e-maintenance. Today, this heterogeneous community has to be federated in order to bring up e-maintenance as a new scientific discipline

Refining Automatically Extracted Knowledge Bases Using Crowdsourcing

OpenAIRE

Li, Chunhua; Zhao, Pengpeng; Sheng, Victor S.; Xian, Xuefeng; Wu, Jian; Cui, Zhiming

2017-01-01

Machine-constructed knowledge bases often contain noisy and inaccurate facts. There exists significant work in developing automated algorithms for knowledge base refinement. Automated approaches improve the quality of knowledge bases but are far from perfect. In this paper, we leverage crowdsourcing to improve the quality of automatically extracted knowledge bases. As human labelling is costly, an important research challenge is how we can use limited human resources to maximize the quality i...

Nuclear Knowledge Innovations Assimilation: The Impact of Organizational Knowledge Frames and Triple Helix Dynamics of Knowledge Base

International Nuclear Information System (INIS)

Hossain, M. D.; Sultana, T.

2016-01-01

Full text: Previous research did not investigate the impact of the TH dynamics of knowledge innovations on the nuclear knowledge innovations adoption/assimilation in the organizational context. Hence, the recommendation of R&D policy reformulation seems too broad. These gaps are the prime motivators for the research. In the organizational context, we posit that TH dynamics of knowledge base innovation serves as complements to managers’ knowledge frames related to a technology innovation. We examine interactions between three knowledge frames—integration frame, opportunism frame, and policy knowledge frame, and two TH dynamics of knowledge innovations—bilateral TH dynamics of knowledge innovations and trilateral TH dynamics of knowledge innovations, and their relationship with the assimilation of nuclear knowledge innovations. We aim to research on the issues of the dynamics of knowledge base of innovations involving TH collaborations (university, industry and government) in Bangladesh as a new build nuclear project. As a result, we can find out the impact of TH collaborations on organizational nuclear knowledge innovations management as well as core institutional problems of the knowledge base of innovation systems in terms of R&D policy. Finally, findings identify lack in production of nuclear knowledge innovations and concrete recommendation of R&D policy reformulation. (author

Risk based maintenance to increase safety and decrease costs

International Nuclear Information System (INIS)

Phillips, J.H.

2000-01-01

Risk-Based techniques have been developed for commercial nuclear power plants for the last eight years by a team working through the ASME Center for Research and Technology Development (CRTD). System boundaries and success criteria is defined using the Probabilistic Risk Analysis or Probabilistic Safety Analysis developed to meet the Individual Plant Evaluation. Final ranking of components is by a plant expert panel similar to the one developed for the Maintenance Rule. Components are identified as being high risk-significant or low risk-significant. Maintenance and resources are focused on those components that have the highest risk-significance. The techniques have been developed and applied at a number of plants. Results from the first risk-based inspection pilot plant indicates safety due to pipe failure can be doubled while the inspection reduced to about 80% when compared with current inspection programs. Pilot studies on risk-based testing indicate that about 60% of pumps and 25 to 30% of valves in plants are high safety-significant The reduction in inspection and testing reduces the person-rem exposure and resulting in further increases in safety. These techniques have been documented in publications by the ASME CRTD which are referenced. (author)

The applicability of knowledge-based scheduling to the utilities industry

International Nuclear Information System (INIS)

Yoshimoto, G.; Gargan, R. Jr.; Duggan, P.

1992-01-01

The Electric Power Research Institute (EPRI), Nuclear Power Division, has identified the three major goals of high technology applications for nuclear power plants. These goals are to enhance power production through increasing power generation efficiency, to increase productivity of the operations, and to reduce the threats to the safety of the plant. Our project responds to the second goal by demonstrating that significant productivity increases can be achieved for outage maintenance operations based on existing knowledge-based scheduling technology. Its use can also mitigate threats to potential safety problems by means of the integration of risk assessment features into the scheduler. The scheduling approach uses advanced techniques enabling the automation of the routine scheduling decision process that previously was handled by people. The process of removing conflicts in scheduling is automated. This is achieved by providing activity representations that allow schedulers to express a variety of different scheduling constraints and by implementing scheduling mechanisms that simulate kinds of processes that humans use to find better solutions from a large number of possible solutions. This approach allows schedulers to express detailed constraints between activities and other activities, resources (material and personnel), and requirements that certain states exist for their execution. Our scheduler has already demonstrated its benefit to improving the shuttle processing flow management at Kennedy Space Center. Knowledge-based scheduling techniques should be examined by utilities industry researchers, developers, operators and management for application to utilities planning problems because of its great cost benefit potential. 4 refs., 4 figs

Maintenance optimization and prognostics of residual life - A state of the art report

Energy Technology Data Exchange (ETDEWEB)

Nystad, Bent

2006-01-15

In many industries a huge part of the daily operational costs are related to maintenance. One key function in cutting costs is in optimization of the maintenance efforts. A major task is to change the work culture and work processes from being repair oriented, with focus on repairing breakdowns, to being proactive and maintain critical parts/systems before failures occur. Estimation of residual life distributions is of great need to obtain an optimum preventive maintenance strategy. In this report two approaches for estimation of residual life are discussed. The first model assumes that the residual life follows a Weibull distribution where the parameters are dependent on expert judgement, inspection data, repair data, and technical health trends. The second model is based on a continuous time Markov chain. In maintenance optimization a quantitative approach like the mean residual life estimation is needed in addition to a qualitative approach like the Reliability Centred Maintenance (RCM) methodology to give support for e.g. optimization of the maintenance overhaul intervals.The use of residual life knowledge in opportunistic maintenance is also discussed.(auth)

Artificial Intelligent Platform as Decision Tool for Asset Management, Operations and Maintenance.

Science.gov (United States)

2018-01-04

An Artificial Intelligence (AI) system has been developed and implemented for water, wastewater and reuse plants to improve management of sensors, short and long term maintenance plans, asset and investment management plans. It is based on an integrated approach to capture data from different computer systems and files. It adds a layer of intelligence to the data. It serves as a repository of key current and future operations and maintenance conditions that a plant needs have knowledge of. With this information, it is able to simulate the configuration of processes and assets for those conditions to improve or optimize operations, maintenance and asset management, using the IViewOps (Intelligent View of Operations) model. Based on the optimization through model runs, it is able to create output files that can feed data to other systems and inform the staff regarding optimal solutions to the conditions experienced or anticipated in the future.

Maximizing the knowledge base: Knowledge Base+ and the Global Open Knowledgebase

Directory of Open Access Journals (Sweden)

Liam Earney

2013-11-01

Full Text Available The motivation for the two projects discussed in this article is the simple premise that the current inaccuracies of data in the library supply chain are detrimental to the user experience, limit the ability of institutions to effectively manage their collections and that resolving them is increasingly unsustainable at the institutional level. Two projects, Knowledge Base+ (KB+ in the UK and Global Open Knowledgebase (GOKb in the USA, are working in cooperation with a range of other partners, and adopting a communitycentric approach to address these issues and broaden the scope and utility of knowledge bases more generally. The belief is that only through collaboration at a wide range of levels and on a number of fronts can these challenges be overcome.

Improving patient knowledge about sacral nerve stimulation using a patient based educational video.

Science.gov (United States)

Jeppson, Peter Clegg; Clark, Melissa A; Hampton, Brittany Star; Raker, Christina A; Sung, Vivian W

2013-10-01

We developed a patient based educational video to address the information needs of women considering sacral nerve stimulation for overactive bladder. Five semistructured focus groups were used to identify patient knowledge gaps, information needs, patient acceptable terminology and video content preferences for a patient based sacral nerve stimulation educational video. Each session was transcribed, independently coded by 2 coders and examined using an iterative method. A 16-minute educational video was created to address previously identified knowledge gaps and information needs using patient footage, 3-dimensional animation and peer reviewed literature. We developed a questionnaire to evaluate participant sacral nerve stimulation knowledge and therapy attitudes. We then performed a randomized trial to assess the effect of the educational video vs the manufacturer video on patient knowledge and attitudes using our questionnaire. We identified 10 patient important domains, including 1) anatomy, 2) expectations, 3) sacral nerve stimulation device efficacy, 4) surgical procedure, 5) surgical/device complications, 6) post-procedure recovery, 7) sacral nerve stimulation side effects, 8) postoperative restrictions, 9) device maintenance and 10) general sacral nerve stimulation information. A total of 40 women with overactive bladder were randomized to watch the educational (20) or manufacturer (20) video. Knowledge scores improved in each group but the educational video group had a greater score improvement (76.6 vs 24.2 points, p <0.0001). Women who watched the educational video reported more favorable attitudes and expectations about sacral nerve stimulation therapy. Women with overactive bladder considering sacral nerve stimulation therapy have specific information needs. The video that we developed to address these needs was associated with improved short-term patient knowledge. Copyright © 2013 American Urological Association Education and Research, Inc

Sociopathic Knowledge Bases: Correct Knowledge Can Be Harmful Even Given Unlimited Computation

Science.gov (United States)

1989-08-01

1757 I Sociopathic Knowledge Bases: Correct Knowledge Can Be Harmful Even Given Unlimited Computation DTIC5 by flELECTE 5David C. Wilkins and Yong...NUMBERSWOKNI PROGRAM RAT TSWOKUI 61153N RR04206 OC 443g-008 11 TITLE (Include Security Classification) Sociopathic Knowledge Bases: Correct Knowledge Can be...probabilistic rules are shown to be sociopathic and so this problem is very widespread. Sociopathicity has important consequences for rule induction

Design and evaluation of augmented reality for nuclear power plant maintenance based on Cognitive activity analysis

International Nuclear Information System (INIS)

Koo, Jwa Jin

2008-02-01

The goals of maintenance in nuclear power plants (NPPs) are to reduce the number of plant shutdowns, to decrease the shutdown time, to minimize the maintenance costs, and to improve nuclear safety. Furthermore, it is difficult for maintenance personnel to conduct work in NPPs due to the complexity of NPPs, safety issues and time constraints. Human errors should be prevented to achieve maintenance goals in NPPs. Therefore, it is necessary to improve working conditions by introducing support systems. Augmented Reality (AR) has the potential to assist with maintenance tasks and make maintenance personnel concentrate on the tasks, which will then the reduced human error and improve human performance. The working procedure for AR systems was designed based on the characteristics of cognitive activity, and an experiment was conducted to estimate the effectiveness of AR. The results indicated that a well-designed working procedure for AR systems was more effective than a conventional paper-based working procedure. In addition, participants made fewer errors using the designed working procedure. AR systems as maintenance support systems are beneficial technology that can improve maintenance performance by reducing cognitive loads and unnecessary movements. An AR application can be attractive and effective at supporting maintenance task

Simulation based comparison of predictive maintenance policies

NARCIS (Netherlands)

Tinga, Tiedo; Janssen, R.H.P.; Steenbergen, R.; van Gelder, P.

2013-01-01

When an asset is operated in variable conditions, its operational efficiency can be improved significantly when the maintenance is performed in a dynamic manner. This means that variations in usage and operating environment are taken into account when deciding on the length of the maintenance

The safety monitor and RCM workstation as complementary tools in risk based maintenance optimization

International Nuclear Information System (INIS)

Rawson, P.D.

2000-01-01

Reliability Centred Maintenance (RCM) represents a proven technique for rendering maintenance activities safer, more effective, and less expensive, in terms of systems unavailability and resource management. However, it is believed that RCM can be enhanced by the additional consideration of operational plant risk. This paper discusses how two computer-based tools, i.e., the RCM Workstation and the Safety Monitor, can complement each other in helping to create a living preventive maintenance strategy. (author)

An Optimization Method for Condition Based Maintenance of Aircraft Fleet Considering Prognostics Uncertainty

Directory of Open Access Journals (Sweden)

Qiang Feng

2014-01-01

Full Text Available An optimization method for condition based maintenance (CBM of aircraft fleet considering prognostics uncertainty is proposed. The CBM and dispatch process of aircraft fleet is analyzed first, and the alternative strategy sets for single aircraft are given. Then, the optimization problem of fleet CBM with lower maintenance cost and dispatch risk is translated to the combinatorial optimization problem of single aircraft strategy. Remain useful life (RUL distribution of the key line replaceable Module (LRM has been transformed into the failure probability of the aircraft and the fleet health status matrix is established. And the calculation method of the costs and risks for mission based on health status matrix and maintenance matrix is given. Further, an optimization method for fleet dispatch and CBM under acceptable risk is proposed based on an improved genetic algorithm. Finally, a fleet of 10 aircrafts is studied to verify the proposed method. The results shows that it could realize optimization and control of the aircraft fleet oriented to mission success.

Health Care Leadership: Managing Knowledge Bases as Stakeholders.

Science.gov (United States)

Rotarius, Timothy

Communities are composed of many organizations. These organizations naturally form clusters based on common patterns of knowledge, skills, and abilities of the individual organizations. Each of these spontaneous clusters represents a distinct knowledge base. The health care knowledge base is shown to be the natural leader of any community. Using the Central Florida region's 5 knowledge bases as an example, each knowledge base is categorized as a distinct type of stakeholder, and then a specific stakeholder management strategy is discussed to facilitate managing both the cooperative potential and the threatening potential of each "knowledge base" stakeholder.

Susquehanna SES maintenance supervisor training and certification

International Nuclear Information System (INIS)

Deckman, M.

1991-01-01

Susquehanna's program targets all Supervisors, Supervisor Candidates, and Temporary Supervisors that are responsible for in-plant maintenance or maintenance support activities, including: mechanical maintenance; electrical maintenance; maintenance support (labor support, radwaste, etc.); mobile construction support (mechanical and electrical); chemistry; health physics; maintenance planning; and instrument and controls. The program integrates the three major areas of direct Supervisory responsibilities: (1) Leadership and Management - Skills that require interpersonal activities that are typically humanistic and subjective; such as coaching, motivating, communications, etc. (2) Technical and Administrative - Knowledge that is directly related to the job of Supervising from the production, regulatory, accountability perspective. These topics are very objective and include training on topics such as workpackages, plant chemistry parameters, radiological concerns, etc. (3) Technical Skills - Ensure each Supervisor is technically competent in the plant systems, components, or equipment he/she is tasked with maintaining or overseeing. Typical skills found in this area are, circuit breaker maintenance, primary system sampling, or overhauling pumps

Knowledge based Entrepreneurship

DEFF Research Database (Denmark)

Heebøll, John

This book is dedicated enterprising people with a technical or a scientific background who consider commercializing ideas and inventions within their field of expertise via a new business activity or a new company. It aims at distilling experiences from many successful and not so successful start......-up ventures from the Technical University of Denmark, 1988 – 2008 into practical, portable knowledge that can be used by future knowledge-based entrepreneurs to set up new companies efficiently or to stay away from it; to do what’s needed and avoid the pitfalls....

Optimization of maintenance programme at Daya Bay Nuclear Power Station based on RCM analysis results

International Nuclear Information System (INIS)

Liu Min

2003-01-01

This paper begins with an introduction to Guangdong Daya Bay Nuclear Power Station (GNPS) and gives a simple introduction to the operations and maintenance documentation system at GNPS. It then will review the maintenance program guidelines base and the associated problems prior to the application of reliability centered maintenance (RCM). How RCM was implemented at GNPS, how the results of RCM analysis were used to optimize the maintenance program and test program, and what is the interface between RCM and the existing maintenance program will be shown. Next, it will show the successful implementation of RCM at GNPS resulted in the following changes: A new understanding of equipment failure challenges operations and maintenance beliefs, maintenance concepts undergo a large change, maintenance program and periodic testing program are continuously modified and optimized, new on-condition maintenance technologies are introduced, non-productive scheduled overhauls are discarded, maintenance costs are effectively controlled, maintenance appropriateness has improved, management of hidden failures is more effective and timely. It will show the benefit of greater equipment reliability brought about by all of these changes, which in turn increases the reliability and safety of the entire power station. (author)

Cognitive Artificial Intelligence Method for Interpreting Transformer Condition Based on Maintenance Data

Directory of Open Access Journals (Sweden)

Karel Octavianus Bachri

2017-07-01

Full Text Available A3S(Arwin-Adang-Aciek-Sembiring is a method of information fusion at a single observation and OMA3S(Observation Multi-time A3S is a method of information fusion for time-series data. This paper proposes OMA3S-based Cognitive Artificial-Intelligence method for interpreting Transformer Condition, which is calculated based on maintenance data from Indonesia National Electric Company (PLN. First, the proposed method is tested using the previously published data, and then followed by implementation on maintenance data. Maintenance data are fused to obtain part condition, and part conditions are fused to obtain transformer condition. Result shows proposed method is valid for DGA fault identification with the average accuracy of 91.1%. The proposed method not only can interpret the major fault, it can also identify the minor fault occurring along with the major fault, allowing early warning feature. Result also shows part conditions can be interpreted using information fusion on maintenance data, and the transformer condition can be interpreted using information fusion on part conditions. The future works on this research is to gather more data, to elaborate more factors to be fused, and to design a cognitive processor that can be used to implement this concept of intelligent instrumentation.

Design of Composite Structures Using Knowledge-Based and Case Based Reasoning

Science.gov (United States)

Lambright, Jonathan Paul

1996-01-01

A method of using knowledge based and case based reasoning to assist designers during conceptual design tasks of composite structures was proposed. The cooperative use of heuristics, procedural knowledge, and previous similar design cases suggests a potential reduction in design cycle time and ultimately product lead time. The hypothesis of this work is that the design process of composite structures can be improved by using Case-Based Reasoning (CBR) and Knowledge-Based (KB) reasoning in the early design stages. The technique of using knowledge-based and case-based reasoning facilitates the gathering of disparate information into one location that is easily and readily available. The method suggests that the inclusion of downstream life-cycle issues into the conceptual design phase reduces potential of defective, and sub-optimal composite structures. Three industry experts were interviewed extensively. The experts provided design rules, previous design cases, and test problems. A Knowledge Based Reasoning system was developed using the CLIPS (C Language Interpretive Procedural System) environment and a Case Based Reasoning System was developed using the Design Memory Utility For Sharing Experiences (MUSE) xviii environment. A Design Characteristic State (DCS) was used to document the design specifications, constraints, and problem areas using attribute-value pair relationships. The DCS provided consistent design information between the knowledge base and case base. Results indicated that the use of knowledge based and case based reasoning provided a robust design environment for composite structures. The knowledge base provided design guidance from well defined rules and procedural knowledge. The case base provided suggestions on design and manufacturing techniques based on previous similar designs and warnings of potential problems and pitfalls. The case base complemented the knowledge base and extended the problem solving capability beyond the existence of

Present state of condition based maintenance (CBM) and its future problem

International Nuclear Information System (INIS)

Hashimoto, Satoshi; Nogami, Takeki; Sugiyama, Naoki

2008-01-01

New inspection system of the nuclear power plant will be introduced from 2008. In this feature, eleven experts from electric utilities, venders and academia described their views or activities about Condition Based Maintenance (CBM) with a new inspection system attracting attention. These are titled as 'Electric utilities view on CBM and its technology', Deployment results of developed CBM technologies', 'Valve diagnostic analysis support system with wireless technology applied', 'Portable vibration checker', 'Tribology diagnosis with no overhaul', 'Infrared thermograph diagnosis', 'Pipewall thinning inspection and management' and, in addition, the US trend and also the development trend of the CBM advancement technology in the vender and university. CBM technology will be introduced step-by-step and contribute to establish reliability based maintenance. (T. Tanaka)

Cultural and Rhetorical Bases for communicating knowledge in web based communities

DEFF Research Database (Denmark)

Kampf, Constance; Kommers, Piet

2008-01-01

Cultural and Rhetorical Bases for communicating knowledge in web based communities How can we extend learner-centred theories for educational technology to include, for instance, the cultural and rhetorical backgrounds which influence participants in online communities as they engage in knowledge...... via web-based communities the intersection of culture and rhetoric in web-based communication rhetoric and discourse in the process of communicating knowledge via technology heuristics for knowledge communication from teaching in online forums connections between identity and knowledge communication...... This call for papers invites papers focused on theoretical frameworks or empirical research which highlights the cultural and/or rhetorical aspects of communicating knowledge in web based communities. We are looking for work that brings together methods and perspectives across disciplines...

Maintenance Production Demand and Capacity Analysis of Third Maintenance Battalion

Science.gov (United States)

2017-12-01

Delivery T/E Table of Equipment TFSMS Total Force Structure Management System TFSP Total Force Structure Process TM Technical Manual T/O Table of...exercises each year, both on Okinawa and throughout the Pacific theater. When equipment requires maintenance beyond the organizational -level...demand was analyzed based on customer cycle time (i.e., time that equipment was in Third Maintenance Battalion custody), maintenance cycle time during

Knowledge management method for knowledge based BWR Core Operation Management System

Energy Technology Data Exchange (ETDEWEB)

Wada, Yutaka; Fukuzaki, Takaharu; Kobayashi, Yasuhiro

1989-03-01

A knowledge management method is proposed to support an except whose knowledge is stored in a knowledge base in the BWR Core Operation Management System. When the alterations in the operation plans are motivated by the expert after evaluating them, the method attempts to find the knowledge which must be modified and to give the expert guidances. In this way the resultant operation plans are improved by modifying values of referenced data. Using data dependency among data, which are defined and referred during inference, data to be modified are retrieved. In generating modification guidances, data reference and definition procedures are classified by syntactic analysis of knowledge. The modified data values are calculated with a sensitivity between the increment in the data to be modified and the resultant one in the performance of operation plans. The efficiency of the knowledge management by the proposed method, when applied to the knowledge based system including 500 pieces of knowledge for BWR control rod programming, is higher than that for interactive use of existing general purpose editors. (author).

Knowledge management method for knowledge based BWR Core Operation Management System

International Nuclear Information System (INIS)

Wada, Yutaka; Fukuzaki, Takaharu; Kobayashi, Yasuhiro

1989-01-01

A knowledge management method is proposed to support an except whose knowledge is stored in a knowledge base in the BWR Core Operation Management System. When the alterations in the operation plans are motivated by the expert after evaluating them, the method attempts to find the knowledge which must be modified and to give the expert guidances. In this way the resultant operation plans are improved by modifying values of referenced data. Using data dependency among data, which are defined and referred during inference, data to be modified are retrieved. In generating modification guidances, data reference and definition procedures are classified by syntactic analysis of knowledge. The modified data values are calculated with a sensitivity between the increment in the data to be modified and the resultant one in the performance of operation plans. The efficiency of the knowledge management by the proposed method, when applied to the knowledge based system including 500 pieces of knowledge for BWR control rod programming, is higher than that for interactive use of existing general purpose editors. (author)

Automated knowledge base development from CAD/CAE databases

Science.gov (United States)

Wright, R. Glenn; Blanchard, Mary

1988-01-01

Knowledge base development requires a substantial investment in time, money, and resources in order to capture the knowledge and information necessary for anything other than trivial applications. This paper addresses a means to integrate the design and knowledge base development process through automated knowledge base development from CAD/CAE databases and files. Benefits of this approach include the development of a more efficient means of knowledge engineering, resulting in the timely creation of large knowledge based systems that are inherently free of error.

On risk-based operation and maintenance of offshore wind turbine components

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2011-01-01

Operation and maintenance are significant contributors to the cost of energy for offshore wind turbines. Optimal planning could rationally be based on Bayesian pre-posterior decision theory, and all costs through the lifetime of the structures should be included. This paper contains a study...... of a generic case where the costs are evaluated for a single wind turbine with a single component. Costs due to inspections, repairs, and lost production are included in the model. The costs are compared for two distinct maintenance strategies, namely with and without inclusion of periodic imperfect...

Maintenance proficiency evaluation test bank

International Nuclear Information System (INIS)

Maier, Loran

2003-01-01

The Maintenance Proficiency Evaluation Test Bank (MPETB) is an Electric Power Research Institute- (EPRJ-) operated, utility-sponsored means of developing, maintaining, and disseminating secure, high-quality written and performance maintenance proficiency tests. EPRTs charter is to ensure that all tests and test items that go into the Test Bank have been validated, screened for reliability, and evaluated to high standards of psychometric excellence. Proficiency tests of maintenance personnel.(mechanics, electricians, and instrumentation and control [I and C] technicians) are most often used to determine if an experienced employee is capable of performing maintenance tasks without further training. Such tests provide objective evidence for decisions to exempt an employee from what, for the employee, is unnecessary training. This leads to considerable savings in training costs and increased productivity because supervisors can assign personnel to tasks at which their competence is proven. The ultimate objective of proficiency evaluation is to ensure that qualified maintenance personnel are available to meet the maintenance requirements of the plant Numerous task-specific MPE tests (both written and performance) have been developed and validated using the EPRI MPE methodology by the utilities participating in the MPETB project A task-specific MPE consists of a multiple-choice written examination and a multi-step performance evaluation that can be used to assess an individual's present knowledge and skill level for a given maintenance task. The MPETB contains MPEs and test items for the mechanical, electrical, and I and C classifications that are readily available to participating utilities. Presently, utilities are placing emphasis on developing MPEs to evaluate outage-related maintenance tasks that demonstrate the competency and qualifications of plant and contractor personnel before the start of outage work. Utilities are also using the MPE methodology and process to

Knowledge-based development in Singapore and Malaysia

OpenAIRE

Menkhoff, Thomas; Gerke, Solvay; Evers, Hans-Dieter; Chay, Yue Wah

2009-01-01

This paper addresses the question how knowledge is used to benefit the economic development of Singapore and Malaysia. Both countries have followed strict science policies to establish knowledge governance regimes for a knowledge-based economy. On the basis of empirical studies in both countries we show, how ethnic and religious diversity impact on the ability to develop an epistemic culture of knowledge sharing and ultimately an innovative knowledge-based economy.

SYSTMS: Systematic approach for the development of strategies for maintenance and surveillance

International Nuclear Information System (INIS)

Yang, J.X.; McCrea, L.; Dam, R.F.; Nickerson, J.H.

2004-01-01

As part of AECL's Integrated PLiM program, the SYSTMS TM tool has been developed to assist in applying the Systematic Assessment of Maintenance (SAM) technology. SYSTMS builds upon AECL's experience in this area, capturing lessons learned to result in an efficient and effective assessment of system maintenance in NPPs. An important feature of SYSTMS is that it provides analysts with needed information that is easy to review and select for inclusion in the system maintenance assessment. This is accomplished through the use of maintenance templates which can be built and tracked using SYSTMS or imported from AECL's own Maintenance Template Database. This database was developed originally to capture information gathered in SAM studies for use in future studies. It has grown to become a central tool for organizing and integrating aging related knowledge from both within AECL and from outside resources. The SYSTMS tool and the Maintenance Template Database work together to provide an effective tool for performing SAM assessments. This combination also becomes an integral part of the Asset Management program development and System based Adaptive Maintenance Program applications. This paper looks at the features of the SYSTMS tool and Maintenance Database, and discusses how these tools are an important part of the AECL Integrated PLiM products and services. (author)

Interval of Routine Maintenance and Maintenance Performance: A Literature Review

Directory of Open Access Journals (Sweden)

Au-Yong Cheong Peng

2016-01-01

Full Text Available In high-rise residential buildings, the quality of facilities management services is significant to the normal operation of the facilities. Unfortunately, lack of concern towards building maintenance, especially preventive maintenance, happens in domestic housing industry in Malaysia. Majority of the maintenance operations of condominiums suffer from lack of planning, lack of proactive maintenance plan, and lack of proper implementation. Thus, this paper reviews the implementation of preventive maintenance strategy, routine maintenance in specific. An extensive review of literature published in 1987 to 2014 is performed for the purpose of this research. The publications are sourced from journal articles, conference proceedings and books. The literature analysis confirms that the routine maintenance of facilities and building services is vital and it can be influential towards the maintenance performance. Subsequently, a theoretical framework is developed, which shows the relationship between routine maintenance of building facilities & services and maintenance performance. The building facilities & services are divided into two categories. They are essential facilities & services that ensure the safety, health, habitability, and operability of buildings; while value-added facilities & services deal with property value, return on investment, and quality living of buildings. Based on the findings, a future research is proposed, which aims to identify the appropriate routine of maintenance for the facilities and services in high-rise residential buildings to improve the maintenance performance.

Geometric Process-Based Maintenance and Optimization Strategy for the Energy Storage Batteries

Directory of Open Access Journals (Sweden)

Yan Li

2016-01-01

Full Text Available Renewable energy is critical for improving energy structure and reducing environment pollution. But its strong fluctuation and randomness have a serious effect on the stability of the microgrid without the coordination of the energy storage batteries. The main factors that influence the development of the energy storage system are the lack of valid operation and maintenance management as well as the cost control. By analyzing the typical characteristics of the energy storage batteries in their life cycle, the geometric process-based model including the deteriorating system and the improving system is firstly built for describing the operation process, the preventive maintenance process, and the corrective maintenance process. In addition, this paper proposes an optimized management strategy, which aims to minimize the long-run average cost of the energy storage batteries by defining the time interval of the detection and preventive maintenance process as well as the optimal corrective maintenance times, subjected to the state of health and the reliability conditions. The simulation is taken under the built model by applying the proposed energy storage batteries’ optimized management strategy, which verifies the effectiveness and applicability of the management strategy, denoting its obvious practicality on the current application.

Paranal maintenance and CMMS experience

Science.gov (United States)

Montano, Nelson

2004-10-01

During the last four years of operations, low technical downtime has been one of the relevant records of the Paranal Observatory. From the beginning of the Very Large Telescope (VLT) project, European Southern Observatory (ESO) has considered the implementation of a proper maintenance strategy a fundamental point in order to ensure low technical down time and preserve the Observatory's assets. The implementation of the maintenance strategy was based on the following aspects: - Strong maintenance sense during the design stage. Line Replacement Unit (LRU) concept, standardization and modularity of the Observatory equipment - Creation of a dedicated team for Maintenance - The implementation of a Computerized Maintenance Management System After four operational years, the result of these aspects has exceeded the expectations; the Observatory has been operating with high availability under a sustainable strategy. The strengths of the maintenance strategy have been based on modern maintenance concepts applied by regular production companies, where any minute of down time involves high cost. The operation of the actual Paranal Maintenance System is based mainly on proactive activities, such as regular inspections, preventive maintenance (PM) and predictive maintenance (PdM) plans. Nevertheless, it has been necessary to implement a strong plan for corrective maintenance (CM). The Spare Parts Strategy has also been an important point linked to the Maintenance Strategy and CMMS implementation. At present, almost 4,000 items related to the Observatory spare parts are loaded into the CMMS database. Currently, we are studying the implementation of a Reliability Centered Maintenance (RCM) project in one of our critical systems The following document presents the actual status of the Paranal Maintenance Strategy and which have been the motivations to implement the established strategy.

Feature-based and object-based attention orientation during short-term memory maintenance.

Science.gov (United States)

Ku, Yixuan

2015-12-01

Top-down attention biases the short-term memory (STM) processing at multiple stages. Orienting attention during the maintenance period of STM by a retrospective cue (retro-cue) strengthens the representation of the cued item and improves the subsequent STM performance. In a recent article, Backer et al. (Backer KC, Binns MA, Alain C. J Neurosci 35: 1307-1318, 2015) extended these findings from the visual to the auditory domain and combined electroencephalography to dissociate neural mechanisms underlying feature-based and object-based attention orientation. Both event-related potentials and neural oscillations explained the behavioral benefits of retro-cues and favored the theory that feature-based and object-based attention orientation were independent. Copyright © 2015 the American Physiological Society.

Using the system maintenance datastore to characterize lifetime maintenance for PLiM

International Nuclear Information System (INIS)

Watson, P.; Dam, R.; Nickerson, J.

2004-01-01

A comprehensive Plant Life Management (PLiM) program involves evaluating a large amount of information. For any plant, there are numerous maintenance, surveillance and inspection programs for the important systems, structures and components. There is extensive industry experience on component failure modes, degradation mechanisms and recommended maintenance practices. This information forms the basis of the aging assessment work, through which improvements to these plant programs are identified. AECL has developed several tools to manage the quantities of information required in aging assessment studies, such as the SYSTMS (SYtematic approach for the development of STrategy for Maintenance and Surveillance) tool and the System Maintenance Datastore (SMD). The SMD has been developed to serve as a hub to a Systematic based Adaptive Maintenance Program (SAMP), by storing maintenance resource requirements for recommended maintenance tasks for use by the other processes in a SAMP. The SMD can be used to (a) quantify the savings or cost of optimising a maintenance program, (b) characterize and understand long term trends in condition-based maintenance due to component aging, (c) quantify the resource savings due to optimum timing of component replacement or general plant refurbishment, and (d) provide aging assessment cost information for input to plant asset evaluation. The SMD contains data for regular maintenance program tasks, plant condition assessment recommendations, and equipment refurbishment costs. A prototype SMD has been developed with data tables populated with information from operating CANDU stations. The SMD is now available to be used either with a SYSTMS evaluation or with a plant's database of maintenance tasks. (author)

Planning of operation & maintenance using risk and reliability based methods

DEFF Research Database (Denmark)

Florian, Mihai; Sørensen, John Dalsgaard

2015-01-01

Operation and maintenance (OM) of offshore wind turbines contributes with a substantial part of the total levelized cost of energy (LCOE). The objective of this paper is to present an application of risk- and reliability-based methods for planning of OM. The theoretical basis is presented...

From Data to Knowledge through Concept-oriented Terminologies

Science.gov (United States)

Cimino, James J.

2000-01-01

Knowledge representation involves enumeration of conceptual symbols and arrangement of these symbols into some meaningful structure. Medical knowledge representation has traditionally focused more on the structure than the symbols. Several significant efforts are under way, at local, national, and international levels, to address the representation of the symbols though the creation of high-quality terminologies that are themselves knowledge based. This paper reviews these efforts, including the Medical Entities Dictionary (MED) in use at Columbia University and the New York Presbyterian Hospital. A decade's experience with the MED is summarized to serve as a proof-of-concept that knowledge-based terminologies can support the use of coded patient data for a variety of knowledge-based activities, including the improved understanding of patient data, the access of information sources relevant to specific patient care problems, the application of expert systems directly to the care of patients, and the discovery of new medical knowledge. The terminological knowledge in the MED has also been used successfully to support clinical application development and maintenance, including that of the MED itself. On the basis of this experience, current efforts to create standard knowledge-based terminologies appear to be justified. PMID:10833166

Cernavoda NPP risk - Based test and maintenance planning - Methodology development

International Nuclear Information System (INIS)

Georgescu, G.; Popa, P.; Petrescu, A.; Naum, M.; Gutu, M.

1997-01-01

The Cernavoda Power Plant starts the commercial operation in November 1996. During operation of the nuclear power plant, several mandatory tests and maintenance are performed on stand-by safety system components to ensure their availability in case of accident. The basic purpose of such activities is the early detection of any failure and degradation, and timely correction of deteriorations. Because of the large number of such activities, emphasis on plant safety and allocation of resources becomes difficult. The probabilistic model and methodology can be effectively used to obtain the risk significance of these activities so that the resources are directed to the most important areas. The proposed Research Contract activity is strongly connected with other safety related areas under development. Since, the Cernavoda Probabilistic Safety Evaluation Level 1 PSA Study (CPSE) was performed and now the study is revised taking into account the as-built information, it is recommended to implement into the model the necessary modeling features to support further PSA application, especially related to Test and Maintenance optimization. Methods need to be developed in order to apply the PSA model including risk information together with other needed information for Test and Maintenance optimization. Also, in parallel with the CPSE study updating, the software interface for the PSA model is under development (Risk Monitor Software class), methods and models needing to be developed for the purpose of using it for qualified monitoring of Test and Maintenance Strategy efficiency. Similar, the Data Collection System need to be appropriate for the purpose of an ongoing implementation of a risk - based Test and Maintenance Strategy. (author). 4 refs, 1 fig

Risk-based inspection and maintenance systems for steam turbines

International Nuclear Information System (INIS)

Fujiyama, Kazunari; Nagai, Satoshi; Akikuni, Yasunari; Fujiwara, Toshihiro; Furuya, Kenichiro; Matsumoto, Shigeru; Takagi, Kentaro; Kawabata, Taro

2004-01-01

The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants

Reliability-centered maintenance for ground-based large optical telescopes and radio antenna arrays

Science.gov (United States)

Marchiori, G.; Formentin, F.; Rampini, F.

2014-07-01

In the last years, EIE GROUP has been more and more involved in large optical telescopes and radio antennas array projects. In this frame, the paper describes a fundamental aspect of the Logistic Support Analysis (LSA) process, that is the application of the Reliability-Centered Maintenance (RCM) methodology for the generation of maintenance plans for ground-based large optical telescopes and radio antennas arrays. This helps maintenance engineers to make sure that the telescopes continue to work properly, doing what their users require them to do in their present operating conditions. The main objective of the RCM process is to establish the complete maintenance regime, with the safe minimum required maintenance, carried out without any risk to personnel, telescope and subsystems. At the same time, a correct application of the RCM allows to increase the cost effectiveness, telescope uptime and items availability, and to provide greater understanding of the level of risk that the organization is managing. At the same time, engineers shall make a great effort since the initial phase of the project to obtain a telescope requiring easy maintenance activities and simple replacement of the major assemblies, taking special care on the accesses design and items location, implementation and design of special lifting equipment and handling devices for the heavy items. This maintenance engineering framework is based on seven points, which lead to the main steps of the RCM program. The initial steps of the RCM process consist of: system selection and data collection (MTBF, MTTR, etc.), definition of system boundaries and operating context, telescope description with the use of functional block diagrams, and the running of a FMECA to address the dominant causes of equipment failure and to lay down the Critical Items List. In the second part of the process the RCM logic is applied, which helps to determine the appropriate maintenance tasks for each identified failure mode. Once

An Algebraic Approach to Knowledge Bases Informational Equivalence

OpenAIRE

Plotkin, B.; Plotkin, T.

2003-01-01

In this paper we study the notion of knowledge from the positions of universal algebra and algebraic logic. We consider first order knowledge which is based on first order logic. We define categories of knowledge and knowledge bases. These notions are defined for the fixed subject of knowledge. The key notion of informational equivalence of two knowledge bases is introduced. We use the idea of equivalence of categories in this definition. We prove that for finite models there is a clear way t...

Maintenance cost optimization in condition based maintenance: a case study for critical facilities

OpenAIRE

Filippo De Carlo; Maria Antonietta Arleo

2013-01-01

The increasing availability required to industrial plants and the limited budget often existing to assure it, require a careful formulation of maintenance optimization models. This need is primary for process plants, for which minimization of stops and maximization of their availability, are essential for ensuring targeted production and, therefore, profitability. In this context, the choice of the maintenance strategy is hence fundamental, depending on the system features and then on the eff...

Computer-Based Simulations for Maintenance Training: Current ARI Research. Technical Report 544.

Science.gov (United States)

Knerr, Bruce W.; And Others

Three research efforts that used computer-based simulations for maintenance training were in progress when this report was written: Game-Based Learning, which investigated the use of computer-based games to train electronics diagnostic skills; Human Performance in Fault Diagnosis Tasks, which evaluated the use of context-free tasks to train…

The Status Quo of Ontology Learning from Unstructured Knowledge Sources for Knowledge Management

OpenAIRE

Scheuermann , Andreas; Obermann , Jens

2012-01-01

International audience; In the global race for competitive advantage Knowledge Management gains increasing importance for companies. The purposeful and systematic creation, maintenance, and transfer of unstructured knowledge sources demands for advanced Information Technology. Ontologies constitute a basic ingredient of Knowledge Management; thus, ontology learning from unstructured knowledge sources is of particular interest since it bears the potential to bring significant advantages for Kn...

Improving the TRIGA facility maintenance by predictive maintenance techniques

International Nuclear Information System (INIS)

Preda, M.; Sabau, C.; Barbalata, E.

1997-01-01

This work deals with the specific operation of equipment in radioactive environment or in conditions allowing radioactive contamination. The requirements of remote operation ensuring the operators' protection are presented. Also, the requirements of international standards issued by IAEA-Vienna are reviewed. The organizational withdraws of the maintenance activities, based on the standards and maintenance and repair directives still in force, are shown. It is emphasized the fact that this type of maintenance was adequate to a given level of technical development, characteristic for pre-computerized industry, but, at present, it is obsolete and uneconomic both in utilization and maintenance. Such a system constitutes already a burden hindering the efforts of maximizing the availability, maintenance, prolongation the service life of equipment and utilities, finally, of increasing the efficiency of complex installations. Moreover, the predictive maintenance techniques are strongly requested by the character of radioactive installations precluding the direct access in given zones (a potential risk of irradiation or radioactive contamination) of installations during operation. The results obtained by applying the predictive maintenance techniques in the operation of the double circuit irradiation loop, used in the TRIGA reactors, are presented

Research on gesture recognition of augmented reality maintenance guiding system based on improved SVM

Science.gov (United States)

Zhao, Shouwei; Zhang, Yong; Zhou, Bin; Ma, Dongxi

2014-09-01

Interaction is one of the key techniques of augmented reality (AR) maintenance guiding system. Because of the complexity of the maintenance guiding system's image background and the high dimensionality of gesture characteristics, the whole process of gesture recognition can be divided into three stages which are gesture segmentation, gesture characteristic feature modeling and trick recognition. In segmentation stage, for solving the misrecognition of skin-like region, a segmentation algorithm combing background mode and skin color to preclude some skin-like regions is adopted. In gesture characteristic feature modeling of image attributes stage, plenty of characteristic features are analyzed and acquired, such as structure characteristics, Hu invariant moments features and Fourier descriptor. In trick recognition stage, a classifier based on Support Vector Machine (SVM) is introduced into the augmented reality maintenance guiding process. SVM is a novel learning method based on statistical learning theory, processing academic foundation and excellent learning ability, having a lot of issues in machine learning area and special advantages in dealing with small samples, non-linear pattern recognition at high dimension. The gesture recognition of augmented reality maintenance guiding system is realized by SVM after the granulation of all the characteristic features. The experimental results of the simulation of number gesture recognition and its application in augmented reality maintenance guiding system show that the real-time performance and robustness of gesture recognition of AR maintenance guiding system can be greatly enhanced by improved SVM.

Advanced maintenance strategies for power plant operators - introducing inter-plant life cycle management. ZES research focus 'condition-based maintenance in power engineering'

International Nuclear Information System (INIS)

Graeber, U.

2003-01-01

The optimisation of maintenance activities observed in recent years can be attributed above all to the use and continuing development of testing and diagnostic techniques, to the increased level of system and component automation and to more efficient work organisation. Despite the considerable success of these efforts, the potential for further cost reductions is still far from exhausted. The risks connected to reliability, availability and safety need to be analysed in greater detail in order to ensure the sustainability of the savings already achieved as well as those yet to be realised. The systematic application of condition-based maintenance and the introduction of structured life cycle management are essential prerequisites. Within the framework of its ''Condition-Based Maintenance in Power Engineering'' research focus, the Energy Research Centre (ZES) has set up a specialist network in which experts from various institutes belonging to the Faculty of Mechanical Engineering and the Faculty of Informatic, Electrical Engineering and Information Technology can develop interdisciplinary solutions for advanced maintenance strategies. The ZES offers the industry a platform for cooperating on current issues relating to the supply of energy and supports the movement towards sustainable improvements to competitiveness through research and consulting activities. It applies professional project and quality management procedures to ensure that contracts covering interdisciplinary topics and projects are handled in a coherent manner. (orig.)

Tools for the Knowledge-Based Organization

DEFF Research Database (Denmark)

Ravn, Ib

2002-01-01

exist. They include a Master’s degree in knowledge management, a web- or print-based intelligence hub for the knowledge society, collaboration with the Danish intellectual capital reporting project, ongoing research on expertise and ethics in knowledge workers, a comparative study of competence...

Knowledge and attitude of parents toward oral health maintenance and treatment modalities for their children

Directory of Open Access Journals (Sweden)

Pooja Bodhale

2014-01-01

Full Text Available Background and Aim: Parents have an important role in making decisions about their child′s oral health. The purpose of this study was to determine parental awareness of their children′s oral health maintenance and their attitude toward dental treatment. Materials and Methods: Total 284 parents from different socioeconomic groups participated in the study. Data were collected using a self-administered questionnaire addressing various aspects of knowledge and attitude of parents toward oral health and treatment modalities. Results: Awareness among parents was significantly lower in low socioeconomic group. Their attitude toward dental treatment differed significantly in which only 53% parents from high socioeconomic group preferred going to the pediatric dentist. Conclusion: The level of awareness among parents is relatively low and there is need for the implementation of oral health awareness programs for parents to change their attitude toward dental treatment of their children.

A maintenance optimization model for mission-oriented systems based on Wiener degradation

International Nuclear Information System (INIS)

Guo, Chiming; Wang, Wenbin; Guo, Bo; Si, Xiaosheng

2013-01-01

Over the past few decades, condition-based maintenance (CBM) has attracted many researchers because of its effectiveness and practical significance. This paper deals with mission-oriented systems subject to gradual degradation modeled by a Wiener stochastic process within the context of CBM. For a mission-oriented system, the mission usually has constraints on availability/reliability, the opportunity for maintenance actions, and the monitoring type (continuous or discrete). Furthermore, in practice, a mission-oriented system may undertake some preventive maintenance (PM) and after such PM, the system may return to an intermediate state between an as-good-as new state and an as-bad-as old state, i.e., the PM is not perfect and only partially restores the system. However, very few CBM models integrated these mission constraints together with an imperfect nature of the PM into the course of optimizing the PM policy. This paper develops a model to optimize the PM policy in terms of the maintenance related cost jointly considering the mission constraints and the imperfect PM nature. A numerical example is presented to demonstrate the proposed model. The comparison with the simulated results and the sensitivity analysis show the usefulness of the optimization model for mission-oriented system maintenance presented in this paper.

A cost effective degradation-based maintenance strategy under imperfect repair

International Nuclear Information System (INIS)

Wu, Fan; Niknam, Seyed A.; Kobza, John E.

2015-01-01

An optimization model is developed to minimize the total cost of imperfect degradation-based maintenance by determining an optimal interval of condition monitoring and the degradation level after imperfect preventive repairs. The decision model is based on a novel cost model that considers functional relationship between the expected degradation reduction and the cost of preventive repairs. The decision model is applied to simulated vibration signals with a variety of specifications of cost values and degradation model parameters. This study has initiated a new area for the research of cost effective maintenance strategies. The results clearly indicate the significance of the proposed model and the decision variables under the objective of minimal cost. For instance, the results indicate direct relationship between the optimal length of monitoring interval and the monitoring cost. However, longer monitoring interval increases the risk of failure, and therefore, more degradation reduction is needed. By increasing the slope of cumulative degradation, the cost effective strategy advocates taking more frequent monitoring. The optimal degradation level after each preventive repair is not so sensitive to the change in the degradation slope due to the uncertainty associated with degradation patterns. - Highlights: • Discuss the relationship of degradation reduction and maintenance cost. • Determine the optimal interval of condition monitoring with minimal cost. • Identify the optimal degradation level after imperfect preventive repairs. • Discuss the effects of change in the slope of cumulative degradation.

KNOWLEDGE AND XML BASED CAPP SYSTEM

Institute of Scientific and Technical Information of China (English)

ZHANG Shijie; SONG Laigang

2006-01-01

In order to enhance the intelligent level of system and improve the interactivity with other systems, a knowledge and XML based computer aided process planning (CAPP) system is implemented. It includes user management, bill of materials(BOM) management, knowledge based process planning, knowledge management and database maintaining sub-systems. This kind of nesting knowledge representation method the system provided can represent complicated arithmetic and logical relationship to deal with process planning tasks. With the representation and manipulation of XML based technological file, the system solves some important problems in web environment such as information interactive efficiency and refreshing of web page. The CAPP system is written in ASP VBScript, JavaScript, Visual C++ languages and Oracle database. At present, the CAPP system is running in Shenyang Machine Tools. The functions of it meet the requirements of enterprise production.

Routine maintenance: safety term based work selection; Selecao de trabalho baseado no prazo seguro

Energy Technology Data Exchange (ETDEWEB)

Camargo, Albair de; Filho, Antnio S.; Brendler, Fabiano E.; Adamatti, Gilberto A.; Naruto, Itiro; Araujo, Luiz C.F.; Puerari, Roberto [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2004-07-01

This work has objective to present the experience of improvement of routine maintenance system in some refineries of the PETROBRAS system, with the purpose to increase the efficiency in the Industrial Maintenance Management (cost), Utilization and HSE (Health, Safety and Environment), key of success of a petroleum company. The new system is based on the implantation of the culture of work selection in the safe period, through elaboration of new maintenance procedure, with emphasis in decisions shared between Operation and Maintenance Team, resulting in reduction of emergencies, making possible contract of services of maintenance for packages and improved allocation of resources. This work treat about improvement of the system in use, in view of that it has already taken in consideration the consequence of fail in the maintenance with participation of the operators. Besides of these challenge, this modification was made without causing riots in the process of implantation of SAP. As main result, financial profits had got better of resources with increase of safety, considering that they are analyzed in a way it that systematized potential risks. (author)

A reliability-based preventive maintenance methodology for the projection spot welding machine

Directory of Open Access Journals (Sweden)

Fayzimatov Ulugbek

2018-06-01

Full Text Available An effective operations of a projection spot welding (PSW machine is closely related to the effec-tiveness of the maintenance. Timely maintenance can prevent failures and improve reliability and maintainability of the machine. Therefore, establishing the maintenance frequency for the welding machine is one of the most important tasks for plant engineers. In this regard, reliability analysis of the welding machine can be used to establish preventive maintenance intervals (PMI and to identify the critical parts of the system. In this reliability and maintainability study, analysis of the PSW machine was carried out. The failure and repair data for analysis were obtained from automobile manufacturing company located in Uzbekistan. The machine was divided into three main sub-systems: electrical, pneumatic and hydraulic. Different distributions functions for all sub-systems was tested and their parameters tabulated. Based on estimated parameters of the analyzed distribu-tions, PMI for the PSW machines sub-systems at different reliability levels was calculated. Finally, preventive measures for enhancing the reliability of the PSW machine sub-systems are suggested.

Competencies development and self-assessment in maintenance management e-training

Science.gov (United States)

Papathanassiou, Nikos; Pistofidis, Petros; Emmanouilidis, Christos

2013-10-01

The maintenance management function requires staff to possess a truly multidisciplinary set of skills. This includes competencies from engineering and information technology to health and safety, management and finance, while also taking into account the normative and legislative issues. This body of knowledge is rarely readily available within a single university course. The potential of e-learning in this field is significant, as it is a flexible and less costly alternative to conventional training. Furthermore, trainees can follow their own pace, as their available time is often a commodity. This article discusses the development of tools to support competencies development and self-assessment in maintenance management. Based on requirements arising from professional bodies' guidelines and a user survey, the developed tools implement a dedicated maintenance management training curriculum. The results from pilot testing on academic and industrial user groups are discussed and user evaluations are linked with specific e-learning design issues.

Adaptive Knowledge Management of Project-Based Learning

Science.gov (United States)

Tilchin, Oleg; Kittany, Mohamed

2016-01-01

The goal of an approach to Adaptive Knowledge Management (AKM) of project-based learning (PBL) is to intensify subject study through guiding, inducing, and facilitating development knowledge, accountability skills, and collaborative skills of students. Knowledge development is attained by knowledge acquisition, knowledge sharing, and knowledge…

Imperfect Preventive Maintenance Model Study Based On Reliability Limitation

Directory of Open Access Journals (Sweden)

Zhou Qian

2016-01-01

Full Text Available Effective maintenance is crucial for equipment performance in industry. Imperfect maintenance conform to actual failure process. Taking the dynamic preventive maintenance cost into account, the preventive maintenance model was constructed by using age reduction factor. The model regards the minimization of repair cost rate as final target. It use allowed smallest reliability as the replacement condition. Equipment life was assumed to follow two parameters Weibull distribution since it was one of the most commonly adopted distributions to fit cumulative failure problems. Eventually the example verifies the rationality and benefits of the model.

A framework for the design of a voice-activated, intelligent, and hypermedia-based aircraft maintenance manual

Science.gov (United States)

Patankar, Manoj Shashikant

Federal Aviation Regulations require Aviation Maintenance Technicians (AMTs) to refer to approved maintenance manuals when performing maintenance on airworthy aircraft. Because these manuals are paper-based, larger the size of the aircraft, more cumbersome are the manuals. Federal Aviation Administration (FAA) recognized the difficulties associated with the use of large manuals and conducted studies on the use of electronic media as an alternative to the traditional paper format. However, these techniques do not employ any artificial intelligence technologies and the user interface is limited to either a keyboard or a stylus pen. The primary emphasis of this research was to design a generic framework that would allow future development of voice-activated, intelligent, and hypermedia-based aircraft maintenance manuals. A prototype (VIHAMS-Voice-activated, Intelligent, and Hypermedia-based Aircraft Maintenance System) was developed, as a secondary emphasis, using the design and development techniques that evolved from this research. An evolutionary software design approach was used to design the proposed framework and the structured rapid prototyping technique was used to produce the VIHAMS prototype. VoiceAssist by Creative Labs was used to provide the voice interface so that the users (AMTs) could keep their hands free to work on the aircraft while maintaining complete control over the computer through discrete voice commands. KnowledgePro for Windows sp{TM}, an expert system shell, provided "intelligence" to the prototype. As a result of this intelligence, the system provided expert guidance to the user. The core information contained in conventional manuals was available in a hypermedia format. The prototype's operating hardware included a notebook computer with a fully functional audio system. An external microphone and the built-in speaker served as the input and output devices (along with the color monitor), respectively. Federal Aviation Administration

Monitoring Knowledge Base (MKB)

Data.gov (United States)

U.S. Environmental Protection Agency — The Monitoring Knowledge Base (MKB) is a compilation of emissions measurement and monitoring techniques associated with air pollution control devices, industrial...

NaviCell: a web-based environment for navigation, curation and maintenance of large molecular interaction maps.

Science.gov (United States)

Kuperstein, Inna; Cohen, David P A; Pook, Stuart; Viara, Eric; Calzone, Laurence; Barillot, Emmanuel; Zinovyev, Andrei

2013-10-07

Molecular biology knowledge can be formalized and systematically represented in a computer-readable form as a comprehensive map of molecular interactions. There exist an increasing number of maps of molecular interactions containing detailed and step-wise description of various cell mechanisms. It is difficult to explore these large maps, to organize discussion of their content and to maintain them. Several efforts were recently made to combine these capabilities together in one environment, and NaviCell is one of them. NaviCell is a web-based environment for exploiting large maps of molecular interactions, created in CellDesigner, allowing their easy exploration, curation and maintenance. It is characterized by a combination of three essential features: (1) efficient map browsing based on Google Maps; (2) semantic zooming for viewing different levels of details or of abstraction of the map and (3) integrated web-based blog for collecting community feedback. NaviCell can be easily used by experts in the field of molecular biology for studying molecular entities of interest in the context of signaling pathways and crosstalk between pathways within a global signaling network. NaviCell allows both exploration of detailed molecular mechanisms represented on the map and a more abstract view of the map up to a top-level modular representation. NaviCell greatly facilitates curation, maintenance and updating the comprehensive maps of molecular interactions in an interactive and user-friendly fashion due to an imbedded blogging system. NaviCell provides user-friendly exploration of large-scale maps of molecular interactions, thanks to Google Maps and WordPress interfaces, with which many users are already familiar. Semantic zooming which is used for navigating geographical maps is adopted for molecular maps in NaviCell, making any level of visualization readable. In addition, NaviCell provides a framework for community-based curation of maps.

Associating current knowledge with that of past experience based on knowledge about automata

Energy Technology Data Exchange (ETDEWEB)

Koenig, E C

1982-01-01

Important to the performance of interactive systems is the ability of its members to associate current knowledge with knowledge of past experience. Knowledge association results in greater detail of a current knowledge and is demonstrated through the use of examples. It is based on knowledge about automata and the knowledge structures are in the form of graphs. 11 references.

Assessing the Value Dimensions of Outsourced Maintenance Services

DEFF Research Database (Denmark)

Toossi, Amir; Lockett, Helen Louise; Raja, Jawwad

2013-01-01

Purpose – The purpose of this paper is to investigate the diverse nature of tangible and intangible value dimensions that contribute to customers’ perception of value from outsourced maintenance services. Design/methodology/approach – A multiple case study approach has been adopted. Repertory grid......, an in-depth structured interviewing technique, has been used in order to draw out the respondents’ hidden constructs in evaluating outsourced maintenance services. Data have been collected from four customer organizations of outsourced maintenance services, and a total of 33 interviews have been...... undertaken. Findings – The paper has identified a range of tangible and intangible value dimensions that are of importance in maintenance outsourcing decision making. The most important value dimensions for maintenance outsourcing were found to be specialist knowledge, accessibility (of the service provider...

Lean Maintenance Applied to Improve Maintenance Efficiency in Thermoelectric Power Plants

Directory of Open Access Journals (Sweden)

Orlando Duran

2017-10-01

Full Text Available Thermoelectric power plants consist of a set of critical equipment that require high levels of availability and reliability. Due to this, maintenance of these physical assets is gaining momentum in industry. Maintenance is considered as an activity that contributes to improving the availability, efficiency and productivity of each piece of equipment. Several techniques have been used to achieve greater efficiencies in maintenance, among which we can find the lean maintenance philosophy. Despite the wide diffusion of lean maintenance, there is no structured method that supports the prescription of lean tools applied to the maintenance function. This paper presents the experience gathered in two lean maintenance projects in thermoelectric power plants. The application of lean techniques was based on using a previously developed multicriterial decision making process that uses the Fuzzy Analytic Hierarchy Process (AHP methodology to carry out a diagnosis and prescription tasks. That methodology allowed the prescription of the appropriated lean techniques to resolve the main deficiencies in maintenance function. The results of applying such lean tools show that important results can be obtained, making the maintenance function in thermoelectric power plants more efficient and lean.

A probabilistic maintenance model for diesel engines

Science.gov (United States)

Pathirana, Shan; Abeygunawardane, Saranga Kumudu

2018-02-01

In this paper, a probabilistic maintenance model is developed for inspection based preventive maintenance of diesel engines based on the practical model concepts discussed in the literature. Developed model is solved using real data obtained from inspection and maintenance histories of diesel engines and experts' views. Reliability indices and costs were calculated for the present maintenance policy of diesel engines. A sensitivity analysis is conducted to observe the effect of inspection based preventive maintenance on the life cycle cost of diesel engines.

A relational data-knowledge base system and its potential in developing a distributed data-knowledge system

Science.gov (United States)

Rahimian, Eric N.; Graves, Sara J.

1988-01-01

A new approach used in constructing a rational data knowledge base system is described. The relational database is well suited for distribution due to its property of allowing data fragmentation and fragmentation transparency. An example is formulated of a simple relational data knowledge base which may be generalized for use in developing a relational distributed data knowledge base system. The efficiency and ease of application of such a data knowledge base management system is briefly discussed. Also discussed are the potentials of the developed model for sharing the data knowledge base as well as the possible areas of difficulty in implementing the relational data knowledge base management system.

Improved quality of input data for maintenance optimization using expert judgment

International Nuclear Information System (INIS)

Oien, Knut

1998-01-01

Most maintenance optimization models need an estimate of the so-called 'naked' failure rate function as input. In practice it is very difficult to estimate the 'naked' failure rate, because overhauls and other preventive maintenance actions tend to 'corrupt' the recorded lifelengths. The purpose of this paper is to stress the importance of utilizing the knowledge of maintenance engineers, i.e., expert judgment, in addition to recorded equipment lifelengths, in order to get credible input data. We have shown that without utilizing expert judgment, the estimated mean time to failure may be strongly biased, often by a factor of 2-3, depending on the life distribution that is assumed. We recommend including a simple question about the mean remaining lifelength on the work-order forms. By this approach the knowledge of maintenance engineers may be incorporated in a simple and cost-effective way

Improving human performance in maintenance personnel

International Nuclear Information System (INIS)

Gonzalez Anez, Francisco; Agueero Agueero, Jorge

2010-01-01

The continuous evolution and improvement of safety-related processes has included the analysis, design and development of training plans for the qualification of maintenance nuclear power plant personnel. In this respect, the international references in this area recommend the establishment of systematic qualification programmes for personnel performing functions or carrying out safety related tasks. Maintenance personnel qualification processes have improved significantly, and training plans have been designed and developed based on Systematic Approach to Training methodology to each job position. These improvements have been clearly reflected in recent training programmes with new training material and training facilities focused not only on developing technical knowledge and skills but also on improving attitudes and safety culture. The objectives of maintenance training facilities such as laboratories, mock-ups real an virtual, hydraulic loops, field simulators and other training material to be used in the maintenance training centre are to cover training necessities for initial and continuous qualification. Evidently, all these improvements made in the qualification of plant personnel should be extended to include supplemental personnel (external or contracted) performing safety-related tasks. The supplemental personnel constitute a very spread group, covering the performance of multiple activities entailing different levels of responsibility. Some of these activities are performed permanently at the plant, while others are occasional or sporadic. In order to establish qualification requirements for these supplemental workers, it is recommended to establish a rigorous analysis of job positions and tasks. The objective will be to identify the qualification requirements to assure competence and safety. (authors)

Problem-Oriented Corporate Knowledge Base Models on the Case-Based Reasoning Approach Basis

Science.gov (United States)

Gluhih, I. N.; Akhmadulin, R. K.

2017-07-01

One of the urgent directions of efficiency enhancement of production processes and enterprises activities management is creation and use of corporate knowledge bases. The article suggests a concept of problem-oriented corporate knowledge bases (PO CKB), in which knowledge is arranged around possible problem situations and represents a tool for making and implementing decisions in such situations. For knowledge representation in PO CKB a case-based reasoning approach is encouraged to use. Under this approach, the content of a case as a knowledge base component has been defined; based on the situation tree a PO CKB knowledge model has been developed, in which the knowledge about typical situations as well as specific examples of situations and solutions have been represented. A generalized problem-oriented corporate knowledge base structural chart and possible modes of its operation have been suggested. The obtained models allow creating and using corporate knowledge bases for support of decision making and implementing, training, staff skill upgrading and analysis of the decisions taken. The universal interpretation of terms “situation” and “solution” adopted in the work allows using the suggested models to develop problem-oriented corporate knowledge bases in different subject domains. It has been suggested to use the developed models for making corporate knowledge bases of the enterprises that operate engineer systems and networks at large production facilities.

Knowledge based economy in European Union

Directory of Open Access Journals (Sweden)

Ecaterina Stănculescu

2012-04-01

Full Text Available Nowadays we assist at a fundamental change from the economy based mainly on resources to the one based mostly on knowledge. The concept has been launched in the last decade of the past century. The knowledge became a production agent and a value creation instrument for whatever country and of course for an entire community like European Union which is constantly concerned by its development and competitiveness. This paper presents the principal characteristics of the present EU preoccupations with the expansion of a knowledge based economy through the 2020 European Development Strategy for smart, sustainable and inclusive economy, and especially for the Framework Programs (Framework Programme 7 and Competitiveness and Innovation Framework Programme.

Experimental study on the plant state estimation for the condition-based maintenance

International Nuclear Information System (INIS)

Harada, J. I.; Takahashi, M.; Kitamura, M.; Wakabayashi, T.

2006-01-01

A framework of maintenance support system based on the plant state estimation using diverse methods has been proposed and the validity of the plant state estimation methods has been experimentally evaluated. The focus has been set on the construction of the BN for the objective system with the scale and complexity as same as real world systems. Another focus has been set on the other functions for maintenance support system such as signal processing tool and similarity matching. The validity of the proposed inference method has been confirmed through numerical experiments. (authors)

Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

Energy Technology Data Exchange (ETDEWEB)

Najjar, B [ER Konsult Utveckling AB, Vaexjoe (Sweden)

1999-12-31

The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

Energy Technology Data Exchange (ETDEWEB)

Najjar, B. [ER Konsult Utveckling AB, Vaexjoe (Sweden)

1998-12-31

The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

A knowledge base browser using hypermedia

Science.gov (United States)

Pocklington, Tony; Wang, Lui

1990-01-01

A hypermedia system is being developed to browse CLIPS (C Language Integrated Production System) knowledge bases. This system will be used to help train flight controllers for the Mission Control Center. Browsing this knowledge base will be accomplished either by having navigating through the various collection nodes that have already been defined, or through the query languages.

A new method of knowledge processing for equipment diagnosis of nuclear power plants

International Nuclear Information System (INIS)

Fujii, M.; Fukumoto, A.; Tai, I.; Morioka, T.

1987-01-01

In this work, the authors complete the development of a new knowledge processing method and representation for equipment diagnosis of nuclear power plants and evaluate its functions by applying to the maintenance and diagnosis support system of the reactor instrumentation. This knowledge processing method system is based on the Cause Generation and Checking concept and has sufficient performance not only in the diagnosis function but also in the man-machine interfacing function. The maintenance and diagnosis support system based on this method leads to the possibility for users to diagnose various phenomena occurred in an objective equipment to the considerable extent by consulting with the system, even if they don't have enough knowledge. With this system, it becomes easy for operators or plant engineers to take immediate actions to counteract against the abnormality. The maintainability of the equipments is improved and MTTR (Mean Time To Repair) is expected to be shorter. This new knowledge processing method is proved to be suited for fault diagnosis of the equipments of nuclear power plants

Cost modelling in maintenance strategy optimisation for infrastructure assets with limited data

International Nuclear Information System (INIS)

Zhang, Wenjuan; Wang, Wenbin

2014-01-01

Our paper reports on the use of cost modelling in maintenance strategy optimisation for infrastructure assets. We present an original approach: the possibility of modelling even when the data and information usually required are not sufficient in quantity and quality. Our method makes use of subjective expert knowledge, and requires information gathered for only a small sample of assets to start with. Bayes linear methods are adopted to combine the subjective expert knowledge with the sample data to estimate the unknown model parameters of the cost model. When new information becomes available, Bayes linear methods also prove useful in updating these estimates. We use a case study from the rail industry to demonstrate our methods. The optimal maintenance strategy is obtained via simulation based on the estimated model parameters and the strategy with the least unit time cost is identified. When the optimal strategy is not followed due to insufficient funding, the future costs of recovering the degraded asset condition are estimated

Systematic maintenance analysis with decision support method and tool for optimizing maintenance programme

International Nuclear Information System (INIS)

Laakso, K.; Simola, K.; Dorrepaal, J.; Skogberg, P.

1999-01-01

This report describes an approach to evaluate the effectiveness of test and maintenance programs of technical systems used during several years. The method combines an analysis of the historical data on faults and repairs with an analysis of the history of periodic testing and preventive maintenance action programs. The application of the maintenance analysis from the methodological point of view in the reliability centered maintenance (RCM) project for Barsebaeck nuclear power plant is described. In order to limit the analysis resources, a method for ranking of objects for maintenance analysis is needed. Preliminary suggestions for changes in maintenance action programs are based on signals from simple maintenance indicators and qualitative analysis of underlying data on failures and maintenance. To facilitate generation of maintenance indicators, and make the maintenance analysis more efficient, a powerful and suitable data treatment tool is needed for analysis of the work order history. In the final maintenance decisions, additional decision criteria must be taken into account, and thus a more formal decision analysis is often needed for decision support. (au)

NASA work unit system file maintenance manual

Science.gov (United States)

1972-01-01

The NASA Work Unit System is a management information system for research tasks (i.e., work units) performed under NASA grants and contracts. It supplies profiles on research efforts and statistics on fund distribution. The file maintenance operator can add, delete and change records at a remote terminal or can submit punched cards to the computer room for batch update. The system is designed for file maintenance by a person with little or no knowledge of data processing techniques.

Maintenance-based prognostics of nuclear plant equipment for long-term operation

Energy Technology Data Exchange (ETDEWEB)

Welz, Zachary; Coble, Jamie; Upadhyaya, Belle; Hines, Wes [University of Tennessee, Knoxville (United States)

2017-08-15

While industry understands the importance of keeping equipment operational and well maintained, the importance of tracking maintenance information in reliability models is often overlooked. Prognostic models can be used to predict the failure times of critical equipment, but more often than not, these models assume that all maintenance actions are the same or do not consider maintenance at all. This study investigates the influence of integrating maintenance information on prognostic model prediction accuracy. By incorporating maintenance information to develop maintenance-dependent prognostic models, prediction accuracy was improved by more than 40% compared with traditional maintenance-independent models. This study acts as a proof of concept, showing the importance of utilizing maintenance information in modern prognostics for industrial equipment.

Basic Concept and Theoretical Study of Condition-based Maintenance for Power Transmission System

Institute of Scientific and Technical Information of China (English)

LIMing; HAN Xueshan; YANG Ming; GUO Zhihong

2011-01-01

The appropriate maintenance time for the single equipment can be found easily and efficiently under the background of condition-based maintenance. However, from the perspective of the whole power system, discrepancy between equipment individual and the whole power system would appear. Once this discrepancy can not be coordinated, it will certainly cause contradiction and conflict between individual equipment and the whole system, and lose the integral efficiency. To solve this contradiction and conflicts is of significant meaning.

Project-based knowledge in organizing open innovation

CERN Document Server

Comacchio, Anna; Pizzi, Claudio

2014-01-01

Enriching understanding of the current theoretical debate on project-based open innovation, ‘Project-based Knowledge in Organizing Open Innovation’ draws on innovation management literature and knowledge-based perspectives to investigate the relationship between knowledge development at project level and the strategic organization of open innovation. Addressing the still open issue of how the firm level should be complemented by studies at the project level of analysis, this book provides theoretical and empirical arguments on the advantages of a more fine-grained level of analysis to understand how firms organize their innovation processes across boundaries. The book also addresses the emerging interest in the management literature on project-based organizations, and on the relevance of project forms of organizing in a knowledge-based economy. Through field research in different industrial settings , this book provides empirical evidence on how firms design open innovation project-by-project and it will ...

Automotive Maintenance Data Base for Model Years 1976-1979. Part I

Science.gov (United States)

1980-12-01

An update of the existing data base was developed to include life cycle maintenance costs of representative vehicles for the model years 1976-1979. Repair costs as a function of time are also developed for a passenger car in each of the compact, subc...

Knowledge-based diagnosis for aerospace systems

Science.gov (United States)

Atkinson, David J.

1988-01-01

The need for automated diagnosis in aerospace systems and the approach of using knowledge-based systems are examined. Research issues in knowledge-based diagnosis which are important for aerospace applications are treated along with a review of recent relevant research developments in Artificial Intelligence. The design and operation of some existing knowledge-based diagnosis systems are described. The systems described and compared include the LES expert system for liquid oxygen loading at NASA Kennedy Space Center, the FAITH diagnosis system developed at the Jet Propulsion Laboratory, the PES procedural expert system developed at SRI International, the CSRL approach developed at Ohio State University, the StarPlan system developed by Ford Aerospace, the IDM integrated diagnostic model, and the DRAPhys diagnostic system developed at NASA Langley Research Center.

Reliability-Based Planning of Inspection, Operation and Maintenance for Offshore Oil & Gas Structures and Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2011-01-01

Reliability-based cost-optimal planning of inspection, maintenance and operation has many applications. In this paper applications for planning of inspections for oil & gas jacket structures and of operation and maintenance of offshore wind turbines are described and illustrated by examples....

Optimizing preventive maintenance

International Nuclear Information System (INIS)

DiCola, F.E.

1988-01-01

The traditional approach to preventive maintenance (PM) is based on adherence to manufacturers's requirements and recommended frequencies. When equipment fails, either new procedures are established or the frequency is increased. This leads to an increase in the number of PM activities, overloading not only maintenance resources, but support as well. There is no correlation between more PM and an increase in equipment reliability. More PM may actually induce failures. Reliability-centered maintenance, a new concept in utility maintenance, is based on identifying system/subsystem functions, failures, and dominant failure modes to develop or revise PM tasks. The activities described in this paper are based on actual implementation of this concept on an ongoing project to upgrade the PM program at one of the largest electric utilities in the country. Optimum PM activities are those that, when implemented, will minimize factors that c cause equipment to fail. One technique described illustrates how equipment performance, failure modes, and causes can be related to minimize the occurrence of failures. Operating history and service life of a component are key factors in determining the most effective PM activities, provided that the factors are related to failure modes and causes

CANDU plant maintenance: Recent developments

International Nuclear Information System (INIS)

Charlebois, P.

2000-01-01

CANDU units have long been recognized for their exceptional safety and reliability. Continuing development in the maintenance area has played a key role in achieving this performance level. For over two decades, safety system availability has been monitored closely and system maintenance programs adjusted accordingly to maintain high levels of performance. But as the plants approach mid life in a more competitive environment and component aging becomes a concern, new methods and techniques are necessary. As a result, recent developments are moving the maintenance program largely from a corrective and preventive approach to predictive and condition based maintenance. The application of these techniques is also being extended to safety related systems. These recent developments include use of reliability centred methods to define system maintenance requirements and strategies. This approach has been implemented on a number of systems at Canadian CANDU plants with positive results. The pilot projects demonstrated that the overall maintenance effort remained relatively constant while the system performance improved. It was also possible to schedule some of the redundant component maintenance during plant operation without adverse impact on system availability. The probabilistic safety assessment was found to be useful in determining the safety implications of component outages. These new maintenance strategies are now making use of predictive and condition based maintenance techniques to anticipate equipment breakdown and schedule preventive maintenance as the need arises rather than time based. Some of these techniques include valve diagnostics, vibration monitoring, oil analysis, thermography. Of course, these tools and techniques must form part of an overall maintenance management system to ensure that maintenance becomes a living program. To facilitate this process and contain costs, new information technology tools are being introduced to provide system engineers

Research on knowledge support technology for product innovation design based on quality function knowledge deployment

Directory of Open Access Journals (Sweden)

Kai Zhang

2016-06-01

Full Text Available Based on the analysis of the relationship between the process of product innovation design and knowledge, this article proposes a theoretical model of quality function knowledge deployment. In order to link up the product innovation design and the knowledge required by the designer, the iterative method of quality function knowledge deployment is refined, as well as the knowledge retrieval model and knowledge support model based on quality function knowledge deployment are established. In the whole life cycle of product design, in view of the different requirements for knowledge in conceptual design stage, components’ configuration stage, process planning stage, and production planning stage, the quality function knowledge deployment model could link up the required knowledge with the engineering characteristics, component characteristics, process characteristics, and production characteristics in the four stages using the mapping relationship between the function characteristics and the knowledge and help the designer to track the required knowledge for realizing product innovation design. In this article, an instance about rewinding machine is given to demonstrate the practicability and validity of product innovation design knowledge support technology based on quality function knowledge deployment.

Utility based maintenance analysis using a Random Sign censoring model

International Nuclear Information System (INIS)

Andres Christen, J.; Ruggeri, Fabrizio; Villa, Enrique

2011-01-01

Industrial systems subject to failures are usually inspected when there are evident signs of an imminent failure. Maintenance is therefore performed at a random time, somehow dependent on the failure mechanism. A competing risk model, namely a Random Sign model, is considered to relate failure and maintenance times. We propose a novel Bayesian analysis of the model and apply it to actual data from a water pump in an oil refinery. The design of an optimal maintenance policy is then discussed under a formal decision theoretic approach, analyzing the goodness of the current maintenance policy and making decisions about the optimal maintenance time.

Condition-based maintenance effectiveness for series–parallel power generation system—A combined Markovian simulation model

International Nuclear Information System (INIS)

Azadeh, A.; Asadzadeh, S.M.; Salehi, N.; Firoozi, M.

2015-01-01

Condition-based maintenance (CBM) is an increasingly applicable policy in the competitive marketplace as a means of improving equipment reliability and efficiency. Not only has maintenance a close relationship with safety but its costs also make it even more attractive issue for researchers. This study proposes a model to evaluate the effectiveness of CBM policy compared to two other maintenance policies: Corrective Maintenance (CM) and Preventive Maintenance (PM). Maintenance policies are compared through two system performance indicators: reliability and cost. To estimate the reliability and costs of the system, the proposed Markovian discrete-event simulation model is developed under each of these policies. The applicability and usefulness of the proposed Markovian simulation model is illustrated for a series–parallel power generation system. The simulated characteristics of CBM system include its prognostics efficiency to estimate remaining useful life of the equipment. Results show that with an efficient prognostics, CBM policy is an effective strategy compared to other maintenance strategies. - Highlights: • A model is developed to evaluate the effectiveness of CBM policy. • Maintenance policies are compared through reliability and cost. • A Markovian simulation model is developed. • A series–parallel power generation system is considered. • CBM is an effective strategy compared to others

Optimization of surface maintenance

International Nuclear Information System (INIS)

Oeverland, E.

1990-01-01

The present conference paper deals with methods of optimizing the surface maintenance of steel-made offshore installations. The paper aims at identifying important approaches to the problems regarding the long-range planning of an economical and cost effective maintenance program. The methods of optimization are based on the obtained experiences from the maintenance of installations on the Norwegian continental shelf. 3 figs

Framework for Risk-based Planning of Operation and Maintenance for Offshore Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2009-01-01

, and to sequential optimal decision making on planning of OM taking into account new information. Deterioration mechanisms such as fatigue, corrosion, wear and erosion are associated with significant uncertainty. Observations of the degree of damage can increase the reliability of predictions, especially......For offshore wind turbines, costs to operation and maintenance (OM) are substantial. This paper describes a risk-based life cycle approach for optimal planning of OM. The approach is based on pre-posterior Bayesian decision theory, and can be used both to overall, initial planning of OM...... in connection with condition-based maintenance. The approach can be used for gearboxes, generators, fatigue cracks, corrosion, etc. This paper also describes how probabilistic indicators can be used to quantify indirect information about the damage state for critical components, e.g. gearboxes....

BIM authoring for an image-based bridge maintenance system of existing cable-supported bridges

Science.gov (United States)

Dang, N. S.; Shim, C. S.

2018-04-01

Infrastructure nowadays is increasingly become the main backbone for the metropolitan development in general. Along with the rise of new facilities, the demand in term of maintenance for the existing bridges is indispensable. Recently, the terminology of “preventive maintenance” is not unfamiliar with the engineer, literally is the use of a bridge maintenance system (BMS) based on a BIM-oriented model. In this paper, the process of generating a BMS based on BIM model is introduced in detail. Data management for this BMS is separated into two modules: site inspection system and information management system. The noteworthy aspect of this model lays on the closed and automatic process of “capture image, generate the technical damage report, and upload/feedback to the BMS” in real-time. A pilot BMS system for a cable-supported bridge is presented which showed a good performance and potential to further development of preventive maintenance.

On risk-based operation and maintenance of offshore wind turbine components

International Nuclear Information System (INIS)

Jessen Nielsen, Jannie; Dalsgaard Sorensen, John

2011-01-01

Operation and maintenance are significant contributors to the cost of energy for offshore wind turbines. Optimal planning could rationally be based on Bayesian pre-posterior decision theory, and all costs through the lifetime of the structures should be included. This paper contains a study of a generic case where the costs are evaluated for a single wind turbine with a single component. Costs due to inspections, repairs, and lost production are included in the model. The costs are compared for two distinct maintenance strategies, namely with and without inclusion of periodic imperfect inspections. Finally the influence of different important parameters, e.g. failure rate, reliability of inspections, inspection interval, and decision rule for repairs, is evaluated.

Maintenance Management in Network Utilities Framework and Practical Implementation

CERN Document Server

Gómez Fernández, Juan F

2012-01-01

In order to satisfy the needs of their customers, network utilities require specially developed maintenance management capabilities. Maintenance Management information systems are essential to ensure control, gain knowledge and improve-decision making in companies dealing with network infrastructure, such as distribution of gas, water, electricity and telecommunications. Maintenance Management in Network Utilities studies specified characteristics of maintenance management in this sector to offer a practical approach to defining and implementing  the best management practices and suitable frameworks.   Divided into three major sections, Maintenance Management in Network Utilities defines a series of stages which can be followed to manage maintenance frameworks properly. Different case studies provide detailed descriptions which illustrate the experience in real company situations. An introduction to the concepts is followed by main sections including: • A Literature Review: covering the basic concepts an...

Upgrade of maintenance technologies of Nuclear Power Plants

International Nuclear Information System (INIS)

Kamada, Kazuaki

2005-01-01

In order to enhance long-term safe and stable operation of Ikata Nuclear Power Plants (NPPs) in more efficient way, maintenance technology upgrade project was started aiming at establishment of simplified and efficient self-maintenance system with affiliated companies. Maintenance technique and supervisor qualification system was introduced after improvement and reinforcement of personnel education and training. Reflecting investigation of maintenance activities of US NPPs and productivity improvement in other industries, preventive maintenance optimization project had been performed such as introduction of key performance indicator (KPI), new system incorporating reliability-centered maintenance (RCM) and condition-based maintenance (CBM), and on-line monitoring and maintenance (OLM) based on risk assessment. Enterprise asset management (EAM) to establish information data base and total productive maintenance (TPM) action for every personnel to participate in self-maintenance was also introduced. (T. Tanaka)

Process fault diagnosis using knowledge-based systems

International Nuclear Information System (INIS)

Sudduth, A.L.

1991-01-01

Advancing technology in process plants has led to increased need for computer based process diagnostic systems to assist the operator. One approach to this problem is to use an embedded knowledge based system to interpret measurement signals. Knowledge based systems using only symptom based rules are inadequate for real time diagnosis of dynamic systems; therefore a model based approach is necessary. Though several forms of model based reasoning have been proposed, the use of qualitative causal models incorporating first principles knowledge of process behavior structure, and function appear to have the most promise as a robust modeling methodology. In this paper the structure of a diagnostic system is described which uses model based reasoning and conventional numerical methods to perform process diagnosis. This system is being applied to emergency diesel generator system in nuclear stations

Nuclear knowledge management overview at EDF

International Nuclear Information System (INIS)

Ballay, J.; Vannieuwenhuyse, J.; Nups, A.

2004-01-01

This paper gives an overview of knowledge management practices within the French nuclear generation park. The study was initially partnered by one of the 19 Nuclear Power-plants, located at Golfech near Toulouse, and then extended to a more general overview. Golfech is a 650 people unit, from which 25 of them were interviewed to carry out the study. This staff was made of managers, experts, seniors and juniors, all of them being working at Golfech in the different skills for nuclear generation needs: driving, engineering, maintenance, safety, environment, etc. They were questioned about their practices, tools and organisations concerning creating, sharing, transferring, and renewing knowledge. A general knowledge management model was derived from this study. It shows that the professional knowledge, in any industrial sector, is the result of four learning processes: an education-oriented process, a codified and normative learning process, a context-based collective learning process and an experience-based individual learning process. These learning processes inter-operate through any kind of activity, and they induce four knowledge structures: the basic knowledge, the technical knowledge, the know-how and the experiential knowledge. In conclusion, the model explains how the firm learns and, in the same time, how everybody as a single individual learns. It is a crucial point to understand how the knowledge-based economy runs, as a constant interconnection between two opposite but complementary forces: the collective and the individual ones. (author)

Innovative techniques in maintenance training

International Nuclear Information System (INIS)

Soileau, J.B.; Blackwell, C.; Rackos, N.; Elmer, L.B.

1991-01-01

Performance based training has its beginning with a Job and Task Analysis (JTA), and culminates with the presentation of the developed training material. For optimum training effectiveness, a post training feedback mechanism is utilized to update and/or upgrade material content. A Job Task Analysis uses subject matter experts and supporting documentation to define the skills and knowledge necessary to perform functions from total position responsibilities to the simplest tasks, depending on desired results. Once skills and knowledge are defined, decisions on needed curriculum can be made including objectives, exams, and training settings (classroom, lab, or job site). This focused curriculum and the determination of best training settings are innovations of the performanced based training system. Past training experience has illustrated that a baseline level of classroom training acts as a catalyst for optimum hands-on training. The trainee exits the training phase able to do the job proficiently. This provides the training customer with quality training with minimum investment. Maintenance Training at Comanche Peak Steam Electric Station (CPSES) integrates the knowledge and skill needs by providing the individual with focused classroom presentations followed by sufficient laboratory time to practice actual task activities. Labs are configured to represent plant equipment and work environment to the maximum extent possible and duplicate in-plant work orders and procedures are used. This allows actions to be analyzed and corrective feedback given as necessary. As an added benefit, any mistakes made during training has minimal, if any, impact on plant performance

Instrumentation maintenance

International Nuclear Information System (INIS)

Mack, D.A.

1976-09-01

It is essential to any research activity that accurate and efficient measurements be made for the experimental parameters under consideration for each individual experiment or test. Satisfactory measurements in turn depend upon having the necessary instruments and the capability of ensuring that they are performing within their intended specifications. This latter requirement can only be achieved by providing an adequate maintenance facility, staffed with personnel competent to understand the problems associated with instrument adjustment and repair. The Instrument Repair Shop at the Lawrence Berkeley Laboratory is designed to achieve this end. The organization, staffing and operation of this system is discussed. Maintenance policy should be based on studies of (1) preventive vs. catastrophic maintenance, (2) records indicating when equipment should be replaced rather than repaired and (3) priorities established to indicate the order in which equipment should be repaired. Upon establishing a workable maintenance policy, the staff should be instructed so that they may provide appropriate scheduled preventive maintenance, calibration and corrective procedures, and emergency repairs. The education, training and experience of the maintenance staff is discussed along with the organization for an efficient operation. The layout of the various repair shops is described in the light of laboratory space and financial constraints

The Relationship between Agriculture Knowledge Bases for Teaching and Sources of Knowledge

Science.gov (United States)

Rice, Amber H.; Kitchel, Tracy

2015-01-01

The purpose of this study was to describe the agriculture knowledge bases for teaching of agriculture teachers and to see if a relationship existed between years of teaching experience, sources of knowledge, and development of pedagogical content knowledge (PCK), using quantitative methods. A model of PCK from mathematics was utilized as a…

Quantified Risk Ranking Model for Condition-Based Risk and Reliability Centered Maintenance

Science.gov (United States)

Chattopadhyaya, Pradip Kumar; Basu, Sushil Kumar; Majumdar, Manik Chandra

2017-06-01

In the recent past, risk and reliability centered maintenance (RRCM) framework is introduced with a shift in the methodological focus from reliability and probabilities (expected values) to reliability, uncertainty and risk. In this paper authors explain a novel methodology for risk quantification and ranking the critical items for prioritizing the maintenance actions on the basis of condition-based risk and reliability centered maintenance (CBRRCM). The critical items are identified through criticality analysis of RPN values of items of a system and the maintenance significant precipitating factors (MSPF) of items are evaluated. The criticality of risk is assessed using three risk coefficients. The likelihood risk coefficient treats the probability as a fuzzy number. The abstract risk coefficient deduces risk influenced by uncertainty, sensitivity besides other factors. The third risk coefficient is called hazardous risk coefficient, which is due to anticipated hazards which may occur in the future and the risk is deduced from criteria of consequences on safety, environment, maintenance and economic risks with corresponding cost for consequences. The characteristic values of all the three risk coefficients are obtained with a particular test. With few more tests on the system, the values may change significantly within controlling range of each coefficient, hence `random number simulation' is resorted to obtain one distinctive value for each coefficient. The risk coefficients are statistically added to obtain final risk coefficient of each critical item and then the final rankings of critical items are estimated. The prioritization in ranking of critical items using the developed mathematical model for risk assessment shall be useful in optimization of financial losses and timing of maintenance actions.

Structural maintenance planning based on historical data of corroded deck plates of tankers

International Nuclear Information System (INIS)

Garbatov, Y.; Guedes Soares, C.

2009-01-01

A probabilistic maintenance and repair analysis of tanker deck plates subjected to general corrosion is presented. The decisions about when to perform maintenance and repair on the structure are studied. Different practical scenarios are analyzed and optimum repair times are proposed. The optimum repair age and intervals are defined based on the statistical analysis of operational data using the Weibull model and some assumptions about the inspection and time needed for repair. The total cost is calculated in normalized form.

Semantics-based plausible reasoning to extend the knowledge coverage of medical knowledge bases for improved clinical decision support.

Science.gov (United States)

Mohammadhassanzadeh, Hossein; Van Woensel, William; Abidi, Samina Raza; Abidi, Syed Sibte Raza

2017-01-01

Capturing complete medical knowledge is challenging-often due to incomplete patient Electronic Health Records (EHR), but also because of valuable, tacit medical knowledge hidden away in physicians' experiences. To extend the coverage of incomplete medical knowledge-based systems beyond their deductive closure, and thus enhance their decision-support capabilities, we argue that innovative, multi-strategy reasoning approaches should be applied. In particular, plausible reasoning mechanisms apply patterns from human thought processes, such as generalization, similarity and interpolation, based on attributional, hierarchical, and relational knowledge. Plausible reasoning mechanisms include inductive reasoning , which generalizes the commonalities among the data to induce new rules, and analogical reasoning , which is guided by data similarities to infer new facts. By further leveraging rich, biomedical Semantic Web ontologies to represent medical knowledge, both known and tentative, we increase the accuracy and expressivity of plausible reasoning, and cope with issues such as data heterogeneity, inconsistency and interoperability. In this paper, we present a Semantic Web-based, multi-strategy reasoning approach, which integrates deductive and plausible reasoning and exploits Semantic Web technology to solve complex clinical decision support queries. We evaluated our system using a real-world medical dataset of patients with hepatitis, from which we randomly removed different percentages of data (5%, 10%, 15%, and 20%) to reflect scenarios with increasing amounts of incomplete medical knowledge. To increase the reliability of the results, we generated 5 independent datasets for each percentage of missing values, which resulted in 20 experimental datasets (in addition to the original dataset). The results show that plausibly inferred knowledge extends the coverage of the knowledge base by, on average, 2%, 7%, 12%, and 16% for datasets with, respectively, 5%, 10%, 15

A Condition Based Maintenance Approach to Forecasting B-1 Aircraft Parts

Science.gov (United States)

2017-03-23

Air Force Institute of Technology AFIT Scholar Theses and Dissertations 3-23-2017 A Condition Based Maintenance Approach to Forecasting B-1 Aircraft...component’s life history where reliability forecasts could be stipulated based on a component’s current condition . One of the major issues their report noted...Engine Condition Monitoring System Specification. Contract Number DOT-CG-80513-A. Grand Prairie, TX. Air Force Materiel Command. (2011) Requirements For

Knowledge-Basing Teaching Professions and Professional Practice

DEFF Research Database (Denmark)

Thingstrup, Signe Hvid

This paper discusses the demand for knowledge-based practice and two different answers to this demand, namely evidence-based thinking and critical-political thinking. The paper discusses the implications these have for views on knowledge and professional development. The paper presents and discus...

Dynamic decision-making for reliability and maintenance analysis of manufacturing systems based on failure effects

Science.gov (United States)

Zhang, Ding; Zhang, Yingjie

2017-09-01

A framework for reliability and maintenance analysis of job shop manufacturing systems is proposed in this paper. An efficient preventive maintenance (PM) policy in terms of failure effects analysis (FEA) is proposed. Subsequently, reliability evaluation and component importance measure based on FEA are performed under the PM policy. A job shop manufacturing system is applied to validate the reliability evaluation and dynamic maintenance policy. Obtained results are compared with existed methods and the effectiveness is validated. Some vague understandings for issues such as network modelling, vulnerabilities identification, the evaluation criteria of repairable systems, as well as PM policy during manufacturing system reliability analysis are elaborated. This framework can help for reliability optimisation and rational maintenance resources allocation of job shop manufacturing systems.

An Enhanced Preventive Maintenance Optimization Model Based on a Three-Stage Failure Process

Directory of Open Access Journals (Sweden)

Ruifeng Yang

2015-01-01

Full Text Available Nuclear power plants are highly complex systems and the issues related to their safety are of primary importance. Probabilistic safety assessment is regarded as the most widespread methodology for studying the safety of nuclear power plants. As maintenance is one of the most important factors for affecting the reliability and safety, an enhanced preventive maintenance optimization model based on a three-stage failure process is proposed. Preventive maintenance is still a dominant maintenance policy due to its easy implementation. In order to correspond to the three-color scheme commonly used in practice, the lifetime of system before failure is divided into three stages, namely, normal, minor defective, and severe defective stages. When the minor defective stage is identified, two measures are considered for comparison: one is that halving the inspection interval only when the minor defective stage is identified at the first time; the other one is that if only identifying the minor defective stage, the subsequent inspection interval is halved. Maintenance is implemented immediately once the severe defective stage is identified. Minimizing the expected cost per unit time is our objective function to optimize the inspection interval. Finally, a numerical example is presented to illustrate the effectiveness of the proposed models.

Prognostics and Condition-Based Maintenance: A New Approach to Precursive Metrics

International Nuclear Information System (INIS)

Jarrell, Donald B.; Sisk, Daniel R.; Bond, Leonard J.

2004-01-01

The assumptions used in the design basis of process equipment have always been as much art as science. The usually imprecise boundaries of the equipments' operational envelope provide opportunities for two major improvements in the operations and maintenance (O and M) of process machinery: (a) the actual versus intended machine environment can be understood and brought into much better alignment and (b) the end goal can define O and M strategies in terms of life cycle and economic management of plant assets.Scientists at the Pacific Northwest National Laboratory (PNNL) have performed experiments aimed at understanding and controlling aging of both safety-specific nuclear plant components and the infrastructure that supports essential plant processes. In this paper we examine the development of aging precursor metrics and their correlation with degradation rate and projected machinery failure.Degradation-specific correlations have been developed at PNNL that will allow accurate physics-based diagnostic and prognostic determinations to be derived from a new view of condition-based maintenance. This view, founded in root cause analysis, is focused on quantifying the primary stressor(s) responsible for degradation in the component of interest and formulating a deterministic relationship between the stressor intensity and the resulting degradation rate. This precursive relationship between the performance, degradation, and underlying stressor set is used to gain a first-principles approach to prognostic determinations. A holistic infrastructure approach, as applied through a conditions-based maintenance framework, will allow intelligent, automated diagnostic and prognostic programming to provide O and M practitioners with an understanding of the condition of their machinery today and an assurance of its operational state tomorrow

A risk-based model for maintenance decision support of civil structures using RAMS

NARCIS (Netherlands)

Viana Da Rocha, T. C.; Stipanovic, I.; Hartmann, A.; Bakker, J.

2017-01-01

As a cornerstone of transportation asset management, risk-based approaches have been used to support maintenance decisions of civil structures. However, ambiguous and subjective risk criteria and inconsistency on the use of risk-based approaches can lead to a fuzzy understanding of the risks

Condition Based Maintenance of Space Exploration Vehicles Using Structural Health Monitoring, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Acellent Technologies proposes to develop an autonomous and automated diagnostic system for condition based maintenance (CBM) of safety critical structures for space...

Towards Modeling False Memory With Computational Knowledge Bases.

Science.gov (United States)

Li, Justin; Kohanyi, Emma

2017-01-01

One challenge to creating realistic cognitive models of memory is the inability to account for the vast common-sense knowledge of human participants. Large computational knowledge bases such as WordNet and DBpedia may offer a solution to this problem but may pose other challenges. This paper explores some of these difficulties through a semantic network spreading activation model of the Deese-Roediger-McDermott false memory task. In three experiments, we show that these knowledge bases only capture a subset of human associations, while irrelevant information introduces noise and makes efficient modeling difficult. We conclude that the contents of these knowledge bases must be augmented and, more important, that the algorithms must be refined and optimized, before large knowledge bases can be widely used for cognitive modeling. Copyright © 2016 Cognitive Science Society, Inc.

Framework for Maintenance Planning

DEFF Research Database (Denmark)

Soares, C. Guedes; Duarte, J. Caldeira; Garbatov, Y.

2010-01-01

the design and during the whole life span of operational use, within an integrated framework founded on risk and reliability based techniques. The document addresses designers, decision makers and professionals responsible for or involved in establishing maintenance plans. The purpose of this document......The present document presents a framework for maintenance planning. Maintenance plays a fundamental role in counteracting degradation effects, which are present in all infrastructure and industrial products. Therefore, maintenance planning is a very critical aspect to consider both during...... is to present maintenance as an integrated approach that needs to be planned, designed, engineered, and controlled by proper qualitative and quantitative techniques. This document outlines the basic premises for maintenance planning and provides the general philosophies that can be followed and points to a best...

An All-Recombinant Protein-Based Culture System Specifically Identifies Hematopoietic Stem Cell Maintenance Factors

Directory of Open Access Journals (Sweden)

Aki Ieyasu

2017-03-01

Full Text Available Hematopoietic stem cells (HSCs are considered one of the most promising therapeutic targets for the treatment of various blood disorders. However, due to difficulties in establishing stable maintenance and expansion of HSCs in vitro, their insufficient supply is a major constraint to transplantation studies. To solve these problems we have developed a fully defined, all-recombinant protein-based culture system. Through this system, we have identified hemopexin (HPX and interleukin-1α as responsible for HSC maintenance in vitro. Subsequent molecular analysis revealed that HPX reduces intracellular reactive oxygen species levels within cultured HSCs. Furthermore, bone marrow immunostaining and 3D immunohistochemistry revealed that HPX is expressed in non-myelinating Schwann cells, known HSC niche constituents. These results highlight the utility of this fully defined all-recombinant protein-based culture system for reproducible in vitro HSC culture and its potential to contribute to the identification of factors responsible for in vitro maintenance, expansion, and differentiation of stem cell populations.

Nuclear knowledge preservation

International Nuclear Information System (INIS)

Bettencourt, Marcia Pires da Luz

2009-01-01

The nuclear technology has encouraged the world development and brought a number of benefits to society. These benefits occurred in important social sectors such as Agriculture, Industry, Health Sciences, Environmental Sciences and the production of energy. The research in the nuclear area is justified, accordingly, as an important factor for science development, technology and innovation. Despite the importance of nuclear energy, there is a collapse in the generation, transmission and sharing of nuclear knowledge. The threat of regression in this area is evidenced by the difficulty of generating new knowledge and practices regarding the maintenance of some critical areas. This project focuses its attention on studying, specifically, the lack of young engineers and technical professionals to replace the older, considered this, an alarming situation. Therefore, it is necessary to identify and record the key skills of experienced workers, through a set of tools to elicitation (capture) this knowledge, as expertise is mainly with people, and is lost when they leave the organization. Against, the Knowledge Management provides methodologies for the process of stimulating the creation, collection and knowledge dissemination process, in order to achieve strategic objectives. This study aims to contribute to the building of a model for the Brazilian nuclear knowledge preservation and, therefore, contributes to the maintenance and innovation of activities in this area. (author)

On the Use of Time-Limited Information for Maintenance Decision Support: A Predictive Approach under Maintenance Constraints

Directory of Open Access Journals (Sweden)

E. Khoury

2013-01-01

Full Text Available This paper deals with a gradually deteriorating system operating under an uncertain environment whose state is only known on a finite rolling horizon. As such, the system is subject to constraints. Maintenance actions can only be planned at imposed times called maintenance opportunities that are available on a limited visibility horizon. This system can, for example, be a commercial vehicle with a monitored critical component that can be maintained only in some specific workshops. Based on the considered system, we aim to use the monitoring data and the time-limited information for maintenance decision support in order to reduce its costs. We propose two predictive maintenance policies based, respectively, on cost and reliability criteria. Classical age-based and condition-based policies are considered as benchmarks. The performance assessment shows the value of the different types of information and the best way to use them in maintenance decision making.

Advanced maintenance strategies for power plant operators - introducing inter-plant life cycle management. ZES research focus 'condition-based maintenance in power engineering'

Energy Technology Data Exchange (ETDEWEB)

Graeber, U.

2003-07-01

The optimisation of maintenance activities observed in recent years can be attributed above all to the use and continuing development of testing and diagnostic techniques, to the increased level of system and component automation and to more efficient work organisation. Despite the considerable success of these efforts, the potential for further cost reductions is still far from exhausted. The risks connected to reliability, availability and safety need to be analysed in greater detail in order to ensure the sustainability of the savings already achieved as well as those yet to be realised. The systematic application of condition-based maintenance and the introduction of structured life cycle management are essential prerequisites. Within the framework of its ''Condition-Based Maintenance in Power Engineering'' research focus, the Energy Research Centre (ZES) has set up a specialist network in which experts from various institutes belonging to the Faculty of Mechanical Engineering and the Faculty of Informatic, Electrical Engineering and Information Technology can develop interdisciplinary solutions for advanced maintenance strategies. The ZES offers the industry a platform for cooperating on current issues relating to the supply of energy and supports the movement towards sustainable improvements to competitiveness through research and consulting activities. It applies professional project and quality management procedures to ensure that contracts covering interdisciplinary topics and projects are handled in a coherent manner. (orig.)

Maintenance strategy for tilting table of rolling mill based on reliability considerations

International Nuclear Information System (INIS)

Deshpande, V.S.; Modak, J.P.

2003-01-01

tilting tables are 14 scheduled on-condition tasks, 10 scheduled on-restoration tasks, seven scheduled discard task. Whereas for 14 failure modes no scheduled maintenance has been proposed. Existing maintenance schedule for tilting tables indicates the maintenance action as and when required. Hence RCM based schedule specifies that additional preventive maintenance tasks need to be executed as compared to none initially. Cost incurred for this can be offset from the savings accrued from reduction in loss of production due to repetitive breakdowns. The methodology of RCM adopted in western industries cannot be applied as it is to Indian industries because of labour oriented nature, partially computerised information systems, non-availability of the information about cost of loss of production due to breakdown and age-reliability pattern of equipment, insufficient maintenance database. These problems can be overcome by development of sound MMIS, formulation of RCM review group and imparting suitable training to acquire the relevant skills in RCM. Thus RCM methodology can be applied to Indian industry for reduction of breakdowns as well as optimisation of preventive maintenance cost. This can further boost up the prospects of Indian industry to offer the products at globally competitive prices

Knowledge management strategies: Enhancing knowledge transfer to clinicians and patients.

Science.gov (United States)

Roemer, Lorrie K; Rocha, Roberto A; Del Fiol, Guilherme; Bradshaw, Richard L; Hanna, Timothy P; Hulse, Nathan C

2006-01-01

At Intermountain Healthcare (Intermountain), executive clinical content experts are responsible for disseminating consistent evidence-based clinical content throughout the enterprise at the point-of-care. With a paper-based system it was difficult to ensure that current information was received and was being used in practice. With electronic information systems multiple applications were supplying similar, but different, vendor-licensed and locally-developed content. These issues influenced the consistency of clinical practice within the enterprise, jeopardized patient and clinician safety, and exposed the enterprise and its employees to potential financial penalties. In response to these issues Intermountain is developing a knowledge management infrastructure providing tools and services to support clinical content development, deployment, maintenance, and communication. The Intermountain knowledge management philosophy includes strategies guiding clinicians and consumers of health information to relevant best practice information with the intention of changing behaviors. This paper presents three case studies describing different information management problems identified within Intermountain, methods used to solve the problems, implementation challenges, and the current status of each project.

Research and Development of a Network-Based Intelligent Maintenance Information System

Institute of Scientific and Technical Information of China (English)

ZANG Tie-gang; YANG Ming-zhong; GUO Shun-sheng

2003-01-01

A maintenance information system is an important part of equipment management. An intelli gent maintenance information system ( IMIS) is a synthesis of network technology, information technology and intelligent technology. The IMIS is used to finish flexible maintenance decision-making and fast maintenance planning, which helps enterprises to effectively reduce maintenance cost and increase working efficiency. Because the IMIS integrates advanced technologies, its performance is better than a traditional one.The difference between an IMIS and a traditional maintenance information system, and the functions, structure, important realizations, and application of an IMIS are discussed in this paper.

Knowledge transfer from building operation to construction

DEFF Research Database (Denmark)

Jensen, Per Anker; Chatzilazarou, Stamatia

2017-01-01

Purpose: To investigate how knowledge that derives from operation and maintenance of buildings can be stored and transferred in order to be reused in a future building project? Design/methodology/approach: The paper is theoretically based on knowledge management with a particular focus...... on interdepartmental knowledge transfer between departments responsible for operation and management and departments responsible for building projects in organisations with large and fast changing building portfolios. The paper includes a case study of the FM organisation of the Technical University of Denmark...... with data collection mainly by interviews with managers and staff in the relevant departments in this organisation. Findings: The case organisation seems to be aware of the importance of sharing and transferring their organisational knowledge. Over the last five years, the organisation has developed...

Automatic Knowledge Base Evolution by Learning Instances

OpenAIRE

Kim, Sundong

2016-01-01

Knowledge base is the way to store structured and unstructured data throughout the web. Since the size of the web is increasing rapidly, there are huge needs to structure the knowledge in a fully automated way. However fully-automated knowledge-base evolution on the Semantic Web is a major challenges, although there are many ontology evolution techniques available. Therefore learning ontology automatically can contribute to the semantic web society significantly. In this paper, we propose ful...

Pooling knowledge and improving safety for contracted works at a large industrial park.

Science.gov (United States)

Agnello, Patrizia; Ansaldi, Silvia; Bragatto, Paolo

2015-01-01

At a large chemical park maintenance is contracted by the major companies operating the plants to many small firms. The cultural and psychological isolation of contractor workers was recognized a root cause of severe accidents in the recent years. That problem is common in chemical industry. The knowledge sharing has been assumed a good key to involve contractors and sub contractors in safety culture and contributing to injuries prevention. The selection of personal protective equipment PPE for the maintenance works has been taken as benchmark to demonstrate the adequateness of the proposed approach. To support plant operators, contractors and subcontractors in PPE discussion, a method has been developed. Its core is a knowledge-base, organized in an Ontology, as suitable for inferring decisions. By means of this tool all stakeholders have merged experience and information and find out the right PPE, to be provided, with adequate training and information package. PPE selection requires sound competencies about process and environmental hazards, including major accident, preventive and protective measures, maintenance activities. These pieces of knowledge previously fragmented among plant operators and contractors, have to be pooled, and used to find out the adequate PPE for a number of maintenance works. The PPE selection is per se important, but it is also a good chance to break the contractors' isolation and involve them in safety objectives. Thus by pooling experience and practical knowledge, the common understanding of safety issues has been strengthened.

Research and development of remote maintenance equipment for ITER divertor maintenance

International Nuclear Information System (INIS)

Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka

2005-02-01

To facilitate easy remote maintainability, the ITER divertor is divided into 60 cassettes, which are transported in the toroidal and radial directions for replacement through maintenance ports located every 90 degrees using the divertor remote maintenance equipment such as in- and ex-vessel transporters. The cassette of 25 tons has to be transported and installed in the vacuum vessel with a positioning accuracy less than 2 mm in the limited space of the vacuum vessel and maintenance port under the intense gamma radiation field. Based on these requirements, the following design and tests were performed. (1) Link mechanism was studied to apply to the transportation of the heavy cassette in the restricted space. A compact mechanism with links for transportation of heavy cassette is designed through the optimization of the link angle taking account of space requirement and force efficiency. As a test result, the lifting capacity of 30 tons (larger than the cassette weight of 25 tons) using two link mechanisms has been demonstrated in the limited space. (2) Compact link mechanism was also studied to apply for locking of the cassette through the optimization of the link angle taking account of space requirement and force efficiency. As a test result, the final positioning accuracy of 0.03 mm for the 25 tons-cassette installation on the vacuum vessel from the initial positioning error of 5 mm has been demonstrated, so that the test result satisfies the requirement less than 2 mm using the link mechanisms in the limited space. (3) Sensor-based control using simple sensors such as optical fiber for divertor maintenance was tested using the full-scale mock-up divertor cassette and remote maintenance equipment. As a result, it is found that the positioning accuracy of 0.16 mm has been achieved by the optical fiber sensor and this value is sufficient for sensor-based control. In addition, the maintenance operation has been carried out through the human-machine interface

Reliability analysis of maintenance operations for railway tracks

International Nuclear Information System (INIS)

Rhayma, N.; Bressolette, Ph.; Breul, P.; Fogli, M.; Saussine, G.

2013-01-01

Railway engineering is confronted with problems due to degradation of the railway network that requires important and costly maintenance work. However, because of the lack of knowledge on the geometrical and mechanical parameters of the track, it is difficult to optimize the maintenance management. In this context, this paper presents a new methodology to analyze the behavior of railway tracks. It combines new diagnostic devices which permit to obtain an important amount of data and thus to make statistics on the geometric and mechanical parameters and a non-intrusive stochastic approach which can be coupled with any mechanical model. Numerical results show the possibilities of this methodology for reliability analysis of different maintenance operations. In the future this approach will give important informations to railway managers to optimize maintenance operations using a reliability analysis

From Evidence-based Management to Management of Non-knowledge

DEFF Research Database (Denmark)

Knudsen, Morten

2017-01-01

Leadership and management are increasingly expected to base themselves on evidence, i.e. knowledge. This article does not disagree that knowledge may be beneficial. Yet, based on sociological insights on the complex relation between knowledge and ignorance, the article argues that more knowledge...

Knowledge Based Help desk System in Nuclear Malaysia

International Nuclear Information System (INIS)

Mohamad Safuan Sulaiman; Abdul Muin Abdul Rahman; Norzalina Nasirudin; Khairiel Adyani Abdul Ghani; Abdul Aziz Mhd Ramli; Mohd Ashhar Khalid

2012-01-01

Knowledge based (K-based) Help desk system is a knowledge oriented web based system that provides support to business process of the technical service providers. It is a multi-centric system which focuses on end-users, technical workers and higher level management through utilization of knowledge which resides and grows within the system. The objectives of the system are to be a user-friendly, capture technical knowledge for efficient performance and educating users for self reliance. These were achieved through the improvement of the help desk business process and better management of technical knowledge. This system has been tested and implemented in Information Technology Center (IT), Engineering Division (BKJ) and Instrumentation and Automation Center (IAC) at the Malaysian Nuclear Agency (Nuclear Malaysia). Higher levels of user satisfaction and faster growth in technical knowledge repository have been recorded in the system. This paper describes the help desk system in the perspective of management of its technical knowledge contributing to strengthening organizational knowledge asset of Nuclear Malaysia as national nuclear research institution. (Author)

Integrated maintenance program (IMP)

International Nuclear Information System (INIS)

Zemdegs, R.T.; Chout, Q.B.

1998-01-01

Approaches to the maintenance of nuclear power plants have undergone significant change in the past several decades. The traditional breakdown approach has been displaced by preventive (calendar-based) maintenance and more recently, by condition-based maintenance (CBM). This is largely driven by the fact that traditional maintenance programs, derived primarily from equipment vendor recommendations, are generally unsuccessful in controlling maintenance costs or equipment failures. Many advances in the maintenance field have taken place since the maintenance plans for Ontario Hydro's nuclear plants were initially established. Ontario Hydro nuclear plant operating costs can be substantially reduced and Incapability Factor improved with the application of modern maintenance processes and tools. Pickering is designated as the lead station for IMP. Of immediate concern is the fact that Pickering Nuclear Division has been experiencing a significant backlog of Operating Preventive Maintenance Callups. This backlog, over 2000, is unacceptable to both station management and the nuclear regulator, the Atomic Energy Control Board. In addition there are over 500 callups in various stages of revision (in hyperspace) without an adequate control nor reporting system to manage their completion. There is also considerable confusion about the classification of l icensing c allups, e.g. callups which are mandatory as a result of legal requirements. Furthermore the ineffectiveness of the Preventive Maintenance (PM) has been the subject of peer audits and Atomic Energy Control Board (AECB) findings over the past several years. The current preventive maintenance ratio PM2 /(PM+CM3) at Pickering ND is less than 20%, due to the current high load of equipment breakdown. This past summer, an Independent Integrated Performance Assessment (IIPA) review at Ontario Hydro confirmed these concerns. Over the past several years, Ontario Hydro nuclear staff have evaluated several programs to improve

A dynamic predictive maintenance policy for complex multi-component systems

International Nuclear Information System (INIS)

Van Horenbeek, Adriaan; Pintelon, Liliane

2013-01-01

The use of prognostic methods in maintenance in order to predict remaining useful life is receiving more attention over the past years. The use of these techniques in maintenance decision making and optimization in multi-component systems is however a still underexplored area. The objective of this paper is to optimally plan maintenance for a multi-component system based on prognostic/predictive information while considering different component dependencies (i.e. economic, structural and stochastic dependence). Consequently, this paper presents a dynamic predictive maintenance policy for multi-component systems that minimizes the long-term mean maintenance cost per unit time. The proposed maintenance policy is a dynamic method as the maintenance schedule is updated when new information on the degradation and remaining useful life of components becomes available. The performance, regarding the objective of minimal long-term mean cost per unit time, of the developed dynamic predictive maintenance policy is compared to five other conventional maintenance policies, these are: block-based maintenance, age-based maintenance, age-based maintenance with grouping, inspection condition-based maintenance and continuous condition-based maintenance. The ability of the predictive maintenance policy to react to changing component deterioration and dependencies within a multi-component system is quantified and the results show significant cost savings

Improvement of testing and maintenance based on fault tree analysis

International Nuclear Information System (INIS)

Cepin, M.

2000-01-01

Testing and maintenance of safety equipment is an important issue, which significantly contributes to safe and efficient operation of a nuclear power plant. In this paper a method, which extends the classical fault tree with time, is presented. Its mathematical model is represented by a set of equations, which include time requirements defined in the house event matrix. House events matrix is a representation of house events switched on and off through the discrete points of time. It includes house events, which timely switch on and off parts of the fault tree in accordance with the status of the plant configuration. Time dependent top event probability is calculated by the fault tree evaluations. Arrangement of components outages is determined on base of minimization of mean system unavailability. The results show that application of the method may improve the time placement of testing and maintenance activities of safety equipment. (author)

Improvement of condition-based maintenance technology by utilization of thermography

International Nuclear Information System (INIS)

Shimada, Hiroki

2004-01-01

In the United States, condition-based maintenance technology comprising IR thermography (hereafter ''thermography'' for short) has been regarded in recent years as the established means for effectively improvement the performance of accident-preventive measures for nuclear power stations. As very few nuclear power plants in Japan have been utilizing the technology, measures for allowing power station personnel to use the technology with ease have been studied on an empirical basis. First, in view of improving the measuring efficiency to determine temperatures more accurately with a single measurement, principal factors affecting the measured temperature values have been analyzed. As a result, it has been found effective for accurate temperature measurement to make use of the table to radiation rates that have been determined for each facility coating specification by using a black body tape and to determine the measuring spot by avoiding rear heat sources (influence of reflection ratio) and background noise (influence of scattered light). Concurrently, as a result of determining the IR attenuation in the atmosphere, thermographic measurement has been found feasible without any significant attenuation as long as the distance is below 10 meters. Further, every power station facility (mainly electrical facilities) that is immune to thermography has been identified. These study results have been documented in the form of the ''Thermography Measurement Manual'' by also including in it the descriptions on abnormal thermal images and the judgment criteria at elevated temperatures that have been used in the United States. Based on these accomplishments, condition-based maintenance technology employing thermography has been applied to on-site investigation of nuclear power stations, and the effectiveness of thermography-aided accident-prevention has been demonstrated by detecting locally temperature rising spots of power cable joints. Moreover, with respect to maintenance

Terminological reference of a knowledge-based system: the data dictionary.

Science.gov (United States)