WorldWideScience

Sample records for model health maintenance

  1. Optimization of maintenance for power system equipment using a predictive health model

    NARCIS (Netherlands)

    Bajracharya, G.; Koltunowicz, T.; Negenborn, R.R.; Papp, Z.; Djairam, D.; Schutter, B.D. de; Smit, J.J.

    2009-01-01

    In this paper, a model-predictive control based framework is proposed for modeling and optimization of the health state of power system equipment. In the framework, a predictive health model is proposed that predicts the health state of the equipment based on its usage and maintenance actions. Based

  2. A Situational Maintenance Model

    DEFF Research Database (Denmark)

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

    1997-01-01

    An overview of trend in maintenance management and presentation of a situational model and an analytical tools for identification of managerial efforts in maintenance.......An overview of trend in maintenance management and presentation of a situational model and an analytical tools for identification of managerial efforts in maintenance....

  3. Flight Crew Health Maintenance

    Science.gov (United States)

    Gullett, C. C.

    1970-01-01

    The health maintenance program for commercial flight crew personnel includes diet, weight control, and exercise to prevent heart disease development and disability grounding. The very high correlation between hypertension and overweight in cardiovascular diseases significantly influences the prognosis for a coronary prone individual and results in a high rejection rate of active military pilots applying for civilian jobs. In addition to physical fitness the major items stressed in pilot selection are: emotional maturity, glucose tolerance, and family health history.

  4. Stakeholders responses on health maintenance organizations ...

    African Journals Online (AJOL)

    National Health Insurance Scheme uses the services of Health Maintenance Organizations to run the scheme. This model of administering a national health insurance scheme is different from how so many other national health insurance programs are run in other parts of the world. The designing of the NHIS to include the ...

  5. Health Maintenance Organization (HMO) Plan

    Science.gov (United States)

    ... Find & compare doctors, hospitals, & other providers Health Maintenance Organization (HMO) Plan In most HMO Plans, you generally ... certain service when needed. Related Resources Preferred Provider Organization (PPO) Private Fee-for-Service (PFFS) Special Needs ...

  6. Buildings Lean Maintenance Implementation Model

    Science.gov (United States)

    Abreu, Antonio; Calado, João; Requeijo, José

    2016-11-01

    Nowadays, companies in global markets have to achieve high levels of performance and competitiveness to stay "alive".Within this assumption, the building maintenance cannot be done in a casual and improvised way due to the costs related. Starting with some discussion about lean management and building maintenance, this paper introduces a model to support the Lean Building Maintenance (LBM) approach. Finally based on a real case study from a Portuguese company, the benefits, challenges and difficulties are presented and discussed.

  7. Building new computational models to support health behavior change and maintenance: new opportunities in behavioral research.

    Science.gov (United States)

    Spruijt-Metz, Donna; Hekler, Eric; Saranummi, Niilo; Intille, Stephen; Korhonen, Ilkka; Nilsen, Wendy; Rivera, Daniel E; Spring, Bonnie; Michie, Susan; Asch, David A; Sanna, Alberto; Salcedo, Vicente Traver; Kukakfa, Rita; Pavel, Misha

    2015-09-01

    Adverse and suboptimal health behaviors and habits are responsible for approximately 40 % of preventable deaths, in addition to their unfavorable effects on quality of life and economics. Our current understanding of human behavior is largely based on static "snapshots" of human behavior, rather than ongoing, dynamic feedback loops of behavior in response to ever-changing biological, social, personal, and environmental states. This paper first discusses how new technologies (i.e., mobile sensors, smartphones, ubiquitous computing, and cloud-enabled processing/computing) and emerging systems modeling techniques enable the development of new, dynamic, and empirical models of human behavior that could facilitate just-in-time adaptive, scalable interventions. The paper then describes concrete steps to the creation of robust dynamic mathematical models of behavior including: (1) establishing "gold standard" measures, (2) the creation of a behavioral ontology for shared language and understanding tools that both enable dynamic theorizing across disciplines, (3) the development of data sharing resources, and (4) facilitating improved sharing of mathematical models and tools to support rapid aggregation of the models. We conclude with the discussion of what might be incorporated into a "knowledge commons," which could help to bring together these disparate activities into a unified system and structure for organizing knowledge about behavior.

  8. Paying for quality not quantity: a wisconsin health maintenance organization proposes an incentive model for reimbursement of chiropractic services.

    Science.gov (United States)

    Pursel, Kevin J; Jacobson, Martin; Stephenson, Kathy

    2012-07-01

    The purpose of this study is to describe a reimbursement model that was developed by one Health Maintenance Organization (HMO) to transition from fee-for-service to add a combination of pay for performance and reporting model of reimbursement for chiropractic care. The previous incentive program used by the HMO provided best-practice education and additional reimbursement incentives for achieving the National Committee for Quality Assurance Back Pain Recognition Program (NCQA-BPRP) recognition status. However, this model had not leveled costs between doctors of chiropractic (DCs). Therefore, the HMO management aimed to develop a reimbursement model to incentivize providers to embrace existing best-practice models and report existing quality metrics. The development goals included the following: it should (1) be as financially predictable as the previous system, (2) cost no more on a per-member basis, (3) meet the coverage needs of its members, and (4) be able to be operationalized. The model should also reward DCs who embraced best practices with compensation, not simply tied to providing more procedures, the new program needed to (1) cause little or no disruption in current billing, (2) be grounded achievable and defined expectations for improvement in quality, and (3) be voluntary, without being unduly punitive, should the DC choose not to participate in the program. The generated model was named the Comprehensive Chiropractic Quality Reimbursement Methodology (CCQRM; pronounced "Quorum"). In this hybrid model, additional reimbursement, beyond pay-for-procedures will be based on unique payment interpretations reporting selected, existing Physician Quality Reporting System (PQRS) codes, meaningful use of electronic health records, and achieving NCQA-BPRP recognition. This model aims to compensate providers using pay-for-performance, pay-for-quality reporting, pay-for-procedure methods. The CCQRM reimbursement model was developed to address the current needs of one

  9. 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.

  10. The clinical obesity maintenance model: an integration of psychological constructs including mood, emotional regulation, disordered overeating, habitual cluster behaviours, health literacy and cognitive function.

    Science.gov (United States)

    Raman, Jayanthi; Smith, Evelyn; Hay, Phillipa

    2013-01-01

    Psychological distress and deficits in executive functioning are likely to be important barriers to effective weight loss maintenance. The purpose of this paper is twofold. First, in the light of recent evidence in the fields of neuropsychology and obesity, particularly on the deficits in the executive function in overweight and obese individuals, a conceptual and theoretical framework of obesity maintenance is introduced by way of a clinical obesity maintenance model (COMM). It is argued that psychological variables, that of habitual cluster Behaviors, emotional dysregulation, mood, and health literacy, interact with executive functioning and impact on the overeating/binge eating behaviors of obese individuals. Second, cognizant of this model, it is argued that the focus of obesity management should be extended to include a broader range of maintaining mechanisms, including but not limited to cognitive deficits. Finally, a discussion on potential future directions in research and practice using the COMM is provided.

  11. The Clinical Obesity Maintenance Model: An Integration of Psychological Constructs including Mood, Emotional Regulation, Disordered Overeating, Habitual Cluster Behaviours, Health Literacy and Cognitive Function

    Directory of Open Access Journals (Sweden)

    Jayanthi Raman

    2013-01-01

    Full Text Available Psychological distress and deficits in executive functioning are likely to be important barriers to effective weight loss maintenance. The purpose of this paper is twofold. First, in the light of recent evidence in the fields of neuropsychology and obesity, particularly on the deficits in the executive function in overweight and obese individuals, a conceptual and theoretical framework of obesity maintenance is introduced by way of a clinical obesity maintenance model (COMM. It is argued that psychological variables, that of habitual cluster Behaviors, emotional dysregulation, mood, and health literacy, interact with executive functioning and impact on the overeating/binge eating behaviors of obese individuals. Second, cognizant of this model, it is argued that the focus of obesity management should be extended to include a broader range of maintaining mechanisms, including but not limited to cognitive deficits. Finally, a discussion on potential future directions in research and practice using the COMM is provided.

  12. GRAPHICAL MODELS OF THE AIRCRAFT MAINTENANCE PROCESS

    Directory of Open Access Journals (Sweden)

    Stanislav Vladimirovich Daletskiy

    2017-01-01

    Full Text Available The aircraft maintenance is realized by a rapid sequence of maintenance organizational and technical states, its re- search and analysis are carried out by statistical methods. The maintenance process concludes aircraft technical states con- nected with the objective patterns of technical qualities changes of the aircraft as a maintenance object and organizational states which determine the subjective organization and planning process of aircraft using. The objective maintenance pro- cess is realized in Maintenance and Repair System which does not include maintenance organization and planning and is a set of related elements: aircraft, Maintenance and Repair measures, executors and documentation that sets rules of their interaction for maintaining of the aircraft reliability and readiness for flight. The aircraft organizational and technical states are considered, their characteristics and heuristic estimates of connection in knots and arcs of graphs and of aircraft organi- zational states during regular maintenance and at technical state failure are given. It is shown that in real conditions of air- craft maintenance, planned aircraft technical state control and maintenance control through it, is only defined by Mainte- nance and Repair conditions at a given Maintenance and Repair type and form structures, and correspondingly by setting principles of Maintenance and Repair work types to the execution, due to maintenance, by aircraft and all its units mainte- nance and reconstruction strategies. The realization of planned Maintenance and Repair process determines the one of the constant maintenance component. The proposed graphical models allow to reveal quantitative correlations between graph knots to improve maintenance processes by statistical research methods, what reduces manning, timetable and expenses for providing safe civil aviation aircraft maintenance.

  13. Maintenance Personnel Performance Simulation (MAPPS) model

    International Nuclear Information System (INIS)

    Siegel, A.I.; Bartter, W.D.; Wolf, J.J.; Knee, H.E.; Haas, P.M.

    1984-01-01

    A stochastic computer model for simulating the actions and behavior of nuclear power plant maintenance personnel is described. The model considers personnel, environmental, and motivational variables to yield predictions of maintenance performance quality and time to perform. The mode has been fully developed and sensitivity tested. Additional evaluation of the model is now taking place

  14. DEVELOPMENT OF A MAINTENANCE SCHEDULING MODEL FOR ...

    African Journals Online (AJOL)

    ... of minor maintenance, for each machine within this time span. In order to minimize the total cost of repairs and production. A numerical application of this development model in a case study is presented. Key words: Maintenance, modeling, scheduling, optimization. [Global Jnl Engineering Res. Vol.1(2) 2002: 107-118] ...

  15. The Clinical Obesity Maintenance Model: An Integration of Psychological Constructs including Mood, Emotional Regulation, Disordered Overeating, Habitual Cluster Behaviours, Health Literacy and Cognitive Function

    OpenAIRE

    Raman, Jayanthi; Smith, Evelyn; Hay, Phillipa

    2013-01-01

    Psychological distress and deficits in executive functioning are likely to be important barriers to effective weight loss maintenance. The purpose of this paper is twofold. First, in the light of recent evidence in the fields of neuropsychology and obesity, particularly on the deficits in the executive function in overweight and obese individuals, a conceptual and theoretical framework of obesity maintenance is introduced by way of a clinical obesity maintenance model (COMM). It is argued tha...

  16. The maintenance management framework models and methods for complex systems maintenance

    CERN Document Server

    Crespo Márquez, Adolfo

    2010-01-01

    “The Maintenance Management Framework” describes and reviews the concept, process and framework of modern maintenance management of complex systems; concentrating specifically on modern modelling tools (deterministic and empirical) for maintenance planning and scheduling. It will be bought by engineers and professionals involved in maintenance management, maintenance engineering, operations management, quality, etc. as well as graduate students and researchers in this field.

  17. Maintenance Optimization of High Voltage Substation Model

    Directory of Open Access Journals (Sweden)

    Radim Bris

    2008-01-01

    Full Text Available The real system from practice is selected for optimization purpose in this paper. We describe the real scheme of a high voltage (HV substation in different work states. Model scheme of the HV substation 22 kV is demonstrated within the paper. The scheme serves as input model scheme for the maintenance optimization. The input reliability and cost parameters of all components are given: the preventive and corrective maintenance costs, the actual maintenance period (being optimized, the failure rate and mean time to repair - MTTR.

  18. Shifting physician prescribing to a preferred histamine-2-receptor antagonist. Effects of a multifactorial intervention in a mixed-model health maintenance organization.

    Science.gov (United States)

    Brufsky, J W; Ross-Degnan, D; Calabrese, D; Gao, X; Soumerai, S B

    1998-03-01

    This study was undertaken to determine whether a program of education, therapeutic reevaluation of eligible patients, and performance feedback could shift prescribing to cimetidine from other histamine-2 receptor antagonists, which commonly are used in the management of ulcers and reflux, and reduce costs without increasing rates of ulcer-related hospital admissions. This study used an interrupted monthly time series with comparison series in a large mixed-model health maintenance organization. Physicians employed in health centers (staff model) and physicians in independent medical groups contracting to provide health maintenance organization services (group model) participated. The comparative percentage prescribed of specific histamine-2 receptor antagonists (market share), total histamine-2 receptor antagonist prescribing, cost per histamine-2 receptor antagonist prescription, and the rate of hospitalization for gastrointestinal illness were assessed. In the staff model, therapeutic reevaluation resulted in a sudden increase in market share of the preferred histamine-2 receptor antagonist cimetidine (+53.8%) and a sudden decrease in ranitidine (-44.7%) and famotidine (-4.8%); subsequently, cimetidine market share grew by 1.1% per month. In the group model, therapeutic reevaluation resulted in increased cimetidine market share (+9.7%) and decreased prescribing of other histamine-2 receptor antagonists (ranitidine -11.6%; famotidine -1.2%). Performance feedback did not result in further changes in prescribing in either setting. Use of omeprazole, an expensive alternative, essentially was unchanged by the interventions, as were overall histamine-2 receptor antagonist prescribing and hospital admissions for gastrointestinal illnesses. This intervention, which cost approximately $60,000 to implement, resulted in estimated annual savings in histamine-2 receptor antagonist expenditures of $1.06 million. Annual savings in histamine-2 receptor antagonist expenditures

  19. Dynamics of Implementation and Maintenance of Organizational Health Interventions.

    Science.gov (United States)

    Jalali, Mohammad S; Rahmandad, Hazhir; Bullock, Sally Lawrence; Ammerman, Alice

    2017-08-15

    In this study, we present case studies to explore the dynamics of implementation and maintenance of health interventions. We analyze how specific interventions are built and eroded, how the building and erosion mechanisms are interconnected, and why we can see significantly different erosion rates across otherwise similar organizations. We use multiple comparative obesity prevention case studies to provide empirical information on the mechanisms of interest, and use qualitative systems modeling to integrate our evolving understanding into an internally consistent and transparent theory of the phenomenon. Our preliminary results identify reinforcing feedback mechanisms, including design of organizational processes, motivation of stakeholders, and communication among stakeholders, which influence implementation and maintenance of intervention components. Over time, these feedback mechanisms may drive a wedge between otherwise similar organizations, leading to distinct configurations of implementation and maintenance processes.

  20. Analysis and modeling of rail maintenance costs

    Directory of Open Access Journals (Sweden)

    Amir Ali Bakhshi

    2012-01-01

    Full Text Available Railroad maintenance engineering plays an important role on availability of roads and reducing the cost of railroad incidents. Rail is of the most important parts of railroad industry, which needs regular maintenance since it covers a significant part of total maintenance cost. Any attempt on optimizing total cost of maintenance could substantially reduce the cost of railroad system and it can reduce total cost of the industry. The paper presents a new method to estimate the cost of rail failure using different cost components such as cost of inspection and cost of risk associated with possible accidents. The proposed model of this paper is used for a real-world case study of railroad transportation of Tehran region and the results have been analyzed.

  1. Competition between health maintenance organizations and nonintegrated health insurance companies in health insurance markets.

    Science.gov (United States)

    Baranes, Edmond; Bardey, David

    2015-12-01

    This article examines a model of competition between two types of health insurer: Health Maintenance Organizations (HMOs) and nonintegrated insurers. HMOs vertically integrate health care providers and pay them at a competitive price, while nonintegrated health insurers work as indemnity plans and pay the health care providers freely chosen by policyholders at a wholesale price. Such difference is referred to as an input price effect which, at first glance, favors HMOs. Moreover, we assume that policyholders place a positive value on the provider diversity supplied by their health insurance plan and that this value increases with the probability of disease. Due to the restricted choice of health care providers in HMOs a risk segmentation occurs: policyholders who choose nonintegrated health insurers are characterized by higher risk, which also tends to favor HMOs. Our equilibrium analysis reveals that the equilibrium allocation only depends on the number of HMOs in the case of exclusivity contracts between HMOs and providers. Surprisingly, our model shows that the interplay between risk segmentation and input price effects may generate ambiguous results. More precisely, we reveal that vertical integration in health insurance markets may decrease health insurers' premiums.

  2. 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.

  3. A Novel of Hybrid Maintenance Management Models for Industrial Applications

    OpenAIRE

    Tahir, Zulkifli

    2010-01-01

    It is observed through empirical studies that the effectiveness of industrial process have been increased by a well organized of machines maintenance structure. In current research, a novel of maintenance concept has been designed by hybrid several maintenance management models with Decision Making Grid (DMG), Analytic Hierarchy Process (AHP) and Fuzzy Logic. The concept is designed for maintenance personnel to evaluate and benchmark the maintenance operations and to reveal important maintena...

  4. Increment 23/24 Critical Readiness Review Health Maintenance System

    Science.gov (United States)

    Nieschwitz, Linda

    2010-01-01

    This slide presentation reviews the Health Maintenance System. It includes information on the carbon dioxide (CO2) and moisture removal system (CMRS), the variable oxygen system,rendevous station panels, and the crew contamination protection kit (CCPK).

  5. GRAPHICAL MODELS OF THE AIRCRAFT MAINTENANCE PROCESS

    OpenAIRE

    Stanislav Vladimirovich Daletskiy; Stanislav Stanislavovich Daletskiy

    2017-01-01

    The aircraft maintenance is realized by a rapid sequence of maintenance organizational and technical states, its re- search and analysis are carried out by statistical methods. The maintenance process concludes aircraft technical states con- nected with the objective patterns of technical qualities changes of the aircraft as a maintenance object and organizational states which determine the subjective organization and planning process of aircraft using. The objective maintenance pro- cess is ...

  6. User Delay Cost Model and Facilities Maintenance Cost Model for a Terminal Control Area : Volume 3. User's Manual and Program Documentation for the Facilities Maintenance Cost Model

    Science.gov (United States)

    1978-05-01

    The Facilities Maintenance Cost Model (FMCM) is an analytic model designed to calculate expected annual labor costs of maintenance within a given FAA maintenance sector. The model is programmed in FORTRAN IV and has been demonstrated on the CDC Krono...

  7. Maintenance cost models in deregulated power systems under opportunity costs

    International Nuclear Information System (INIS)

    Al-Arfaj, K.; Dahal, K.; Azaiez, M.N.

    2007-01-01

    In a centralized power system, the operator is responsible for scheduling maintenance. There are different types of maintenance, including corrective maintenance; predictive maintenance; preventive maintenance; and reliability-centred maintenance. The main cause of power failures is poor maintenance. As such, maintenance costs play a significant role in deregulated power systems. They include direct costs associated with material and labor costs as well as indirect costs associated with spare parts inventory, shipment, test equipment, indirect labor, opportunity costs and cost of failure. In maintenance scheduling and planning, the cost function is the only component of the objective function. This paper presented the results of a study in which different components of maintenance costs were modeled. The maintenance models were formulated as an optimization problem with single and multiple objectives and a set of constraints. The maintenance costs models could be used to schedule the maintenance activities of power generators more accurately and to identify the best maintenance strategies over a period of time as they consider failure and opportunity costs in a deregulated environment. 32 refs., 4 tabs., 4 figs

  8. Optimal maintenance policies in incomplete repair models

    International Nuclear Information System (INIS)

    Kahle, Waltraud

    2007-01-01

    We consider an incomplete repair model, that is, the impact of repair is not minimal as in the homogeneous Poisson process and not 'as good as new' as in renewal processes but lies between these boundary cases. The repairs are assumed to impact the failure intensity following a virtual age process of the general form proposed by Kijima. In previous works field data from an industrial setting were used to fit several models. In most cases the estimated rate of occurrence of failures was that of an underlying exponential distribution of the time between failures. In this paper, it is shown that there exist maintenance schedules under which the failure behavior of the failure-repair process becomes a homogeneous Poisson process

  9. 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.

  10. A review of planning models for maintenance and production.

    NARCIS (Netherlands)

    G. Budai-Balke (Gabriella); R. Dekker (Rommert); R.P. Nicolai (Robin)

    2006-01-01

    textabstractIn this article we give an overview of the relation between planning of maintenance and production. On the one hand we consider production planning and scheduling models in which failures and maintenance aspects are taken into account. Next we discuss the planning of maintenance

  11. Applying Psychological Theories to Promote Long-Term Maintenance of Health Behaviors

    Science.gov (United States)

    Joseph, Rodney P.; Daniel, Casey L.; Thind, Herpreet; Benitez, Tanya J.; Pekmezi, Dori

    2014-01-01

    Behavioral health theory provides a framework for researchers to design, implement, and evaluate the effects of health promotion programs. However, limited research has examined theories used in interventions to promote long-term maintenance of health behaviors. The purpose of this review was to evaluate the available literature and identify prominent behavioral health theories used in intervention research to promote maintenance of health behaviors. We reviewed theories used in intervention research assessing long-term maintenance (≥ 6 months post-intervention) of physical activity, weight loss, and smoking cessation. Five prominent behavioral theories were referenced by the 34 studies included in the review: Self-Determination Theory, Theory of Planned Behavior, Social Cognitive Theory, Transtheoretical Model, and Social Ecological Model. Descriptions and examples of applications of these theories are provided. Implications for future research are discussed. PMID:28217036

  12. A production model and maintenance planning model for the process industry

    NARCIS (Netherlands)

    Ashayeri, J.; Teelen, A.; Selen, W.J.

    1995-01-01

    In this paper a model is developed to simultaneously plan preventive maintenance and production in a process industry environment, where maintenance planning is extremely important. The model schedules production jobs and preventive maintenance jobs, while minimizing costs associated with

  13. Stochastic models in reliability and maintenance

    CERN Document Server

    2002-01-01

    Our daily lives can be maintained by the high-technology systems. Computer systems are typical examples of such systems. We can enjoy our modern lives by using many computer systems. Much more importantly, we have to maintain such systems without failure, but cannot predict when such systems will fail and how to fix such systems without delay. A stochastic process is a set of outcomes of a random experiment indexed by time, and is one of the key tools needed to analyze the future behavior quantitatively. Reliability and maintainability technologies are of great interest and importance to the maintenance of such systems. Many mathematical models have been and will be proposed to describe reliability and maintainability systems by using the stochastic processes. The theme of this book is "Stochastic Models in Reliability and Main­ tainability. " This book consists of 12 chapters on the theme above from the different viewpoints of stochastic modeling. Chapter 1 is devoted to "Renewal Processes," under which cla...

  14. Pricing health care services: applications to the health maintenance organization.

    Science.gov (United States)

    Sweeney, R E; Franklin, S P

    1986-01-01

    This article illustrates how management in one type of service industry, the health maintenance organization (HMO), have attempted to formalize pricing. This effort is complicated by both the intangibility of the service delivered and the relatively greater influence in service industries of non-cost price factors such as accessibility, psychology, and delays. The presentation describes a simple computerized approach that allows the marketing manager to formally estimate the effect of incremental changes in rates on the firm's projected patterns of enrollment growth and net revenues. The changes in turn reflect underlying variations in the mix of pricing influences including psychological and other factors. Enrollment projections are crucial to the firm's financial planning and staffing. In the past, most HMO enrollment and revenue projections of this kind were notoriously unreliable. The approach described here makes it possible for HMOs to fine-tune their pricing policies. It also provides a formal and easily understood mechanism by which management can evaluate and reach consensus on alternative scenarios for enrollment growth, staff recruitment and capacity expansion.

  15. Dynamical model of birdsong maintenance and control

    Science.gov (United States)

    Abarbanel, Henry D. I.; Talathi, Sachin S.; Mindlin, Gabriel; Rabinovich, Misha; Gibb, Leif

    2004-11-01

    The neuroethology of song learning, production, and maintenance in songbirds presents interesting similarities to human speech. We have developed a biophysical model of the manner in which song could be maintained in adult songbirds. This model may inform us about the human counterpart to these processes. In songbirds, signals generated in nucleus High Vocal center (HVc) follow a direct route along a premotor pathway to the robust nucleus of the archistriatum (RA) as well as an indirect route to RA through the anterior forebrain pathway (AFP): the neurons of RA are innervated from both sources. HVc expresses very sparse bursts of spikes having interspike intervals of about 2ms . The expressions of these bursts arrive at the RA with a time difference ΔT≈50±10ms between the two pathways. The observed combination of AMPA and NMDA receptors at RA projection neurons suggests that long-term potentiation and long-term depression can both be induced by spike timing plasticity through the pairing of the HVc and AFP signals. We present a dynamical model that stabilizes this synaptic plasticity through a feedback from the RA to the AFP using known connections. The stabilization occurs dynamically and is absent when the RA→AFP connection is removed. This requires a dynamical selection of ΔT . The model does this, and ΔT lies within the observed range. Our model represents an illustration of a functional consequence of activity-dependent plasticity directly connected with neuroethological observations. Within the model the parameters of the AFP, and thus the magnitude of ΔT , can also be tuned to an unstable regime. This means that destabilization might be induced by neuromodulation of the AFP.

  16. 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.

  17. Development and application of degradation modeling to define maintenance practices

    International Nuclear Information System (INIS)

    Stock, D.; Samanta, P.; Vesely, W.

    1994-06-01

    This report presents the development and application of component degradation modeling to analyze degradation effects on reliability and to identify aspects of maintenance practices that mitigate degradation and aging effects. Using continuous time Markov approaches, a component degradation model is discussed that includes information about degradation and maintenance. The component model commonly used in probabilistic risk assessments is a simple case of this general model. The parameters used in the general model have engineering interpretations and can be estimated using data and engineering experience. The generation of equations for specific models, the solution of these equations, and a methodology for estimating the needed parameters are all discussed. Applications in this report show how these models can be used to quantitatively assess the benefits that are expected from maintaining a component, the effects of different maintenance efficiencies, the merits of different maintenance policies, and the interaction of surveillance test intervals with maintenance practices

  18. Modelling inspection policies for building maintenance.

    Science.gov (United States)

    Christer, A H

    1982-08-01

    A method of assessing the potential of an inspection maintenance policy as opposed to an existing breakdown maintenance policy for a building complex is developed. The method is based upon information likely to be available and specific subjective assessments which could be made available. Estimates of the expected number of defects identified at an inspection and the consequential cost saving are presented as functions of the inspection frequency.

  19. 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

  20. 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.

  1. Maintenance modeling and optimization integrating human and material resources

    International Nuclear Information System (INIS)

    Martorell, S.; Villamizar, M.; Carlos, S.; Sanchez, A.

    2010-01-01

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  2. Maintenance modeling and optimization integrating human and material resources

    Energy Technology Data Exchange (ETDEWEB)

    Martorell, S., E-mail: smartore@iqn.upv.e [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Villamizar, M.; Carlos, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Sanchez, A. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia (Spain)

    2010-12-15

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  3. Operations Research Models for Scheduling Railway Infrastructure Maintenance

    NARCIS (Netherlands)

    G. Budai-Balke (Gabriella)

    2009-01-01

    textabstractIn the last decades, maintenance of technical systems has become increasingly impor- tant in many industries. Such systems are transport systems (rail, bus, airplane), civil engineering systems (roads, buildings, bridges), health care (hospitals), communication systems, manufacturing

  4. design of preventive maintenance scheduling model for ...

    African Journals Online (AJOL)

    connected in parallel, Rj(ti) is the reliability of the jth unit at ith time interval, n is the to- tal number of systems (components or units) connected in parallel. Equations (3) and (4) enable us to deter- mine the reliability of all components, units or sub-systems in an industry. 5. System Reliability with Preventive. Maintenance. Fig.

  5. 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.

  6. Maintenance personnel performance simulation (MAPPS): a model for predicting maintenance performance reliability in nuclear power plants

    International Nuclear Information System (INIS)

    Knee, H.E.; Krois, P.A.; Haas, P.M.; Siegel, A.I.; Ryan, T.G.

    1983-01-01

    The NRC has developed a structured, quantitative, predictive methodology in the form of a computerized simulation model for assessing maintainer task performance. Objective of the overall program is to develop, validate, and disseminate a practical, useful, and acceptable methodology for the quantitative assessment of NPP maintenance personnel reliability. The program was organized into four phases: (1) scoping study, (2) model development, (3) model evaluation, and (4) model dissemination. The program is currently nearing completion of Phase 2 - Model Development

  7. Payload maintenance cost model for the space telescope

    Science.gov (United States)

    White, W. L.

    1980-01-01

    An optimum maintenance cost model for the space telescope for a fifteen year mission cycle was developed. Various documents and subsequent updates of failure rates and configurations were made. The reliability of the space telescope for one year, two and one half years, and five years were determined using the failure rates and configurations. The failure rates and configurations were also used in the maintenance simulation computer model which simulate the failure patterns for the fifteen year mission life of the space telescope. Cost algorithms associated with the maintenance options as indicated by the failure patterns were developed and integrated into the model.

  8. Sexual function in F-111 maintenance workers: the study of health outcomes in aircraft maintenance personnel.

    Science.gov (United States)

    Brown, Anthony; Gibson, Richard; Tavener, Meredith; Guest, Maya; D'Este, Catherine; Byles, Julie; Attia, John; Horsley, Keith; Harrex, Warren; Ross, James

    2009-06-01

    In Australia, four formal F-111 fuel tank deseal/reseal (DSRS) repair programs were implemented over more than two decades, each involving different processes and using a range of hazardous substances. However, health concerns were raised by a number of workers. The "Study of Health Outcomes in Aircraft Maintenance Personnel" was commissioned by the Australian Department of Defence to investigate potential adverse health outcomes as a result of being involved in the deseal/reseal processes. To compare measures of sexual function in F-111 aircraft fuel tank DSRS maintenance workers, against two appropriate comparison groups. Exposed and comparison participants completed a postal questionnaire which included general questions of health and health behavior, and two specific questions on sexual functioning. They also completed the International Index of Erectile Function (IIEF) questionnaire. Logistic regression was used to explore exposure status and outcome while adjusting for potential confounders. The three outcomes of interest for this study were the proportion of participants with erectile dysfunction (ED) according to the IIEF, the proportion with self-reported loss of interest in sex, and the proportion with self-reported problems with sexual functioning. Compared with each of the comparison groups, a larger proportion of the exposed group reported sexual problems and were classified as having ED according to the IIEF. In logistic regression, the odds of all three outcomes were higher for exposed participants relative to each comparison group and after adjustment for potentially confounding variables including anxiety and depression. There was a consistent problem with sexual functioning in the exposed group that is not explained by anxiety and depression, and it appears related to DSRS activities.

  9. State-of-the-art Model M-2 Maintenance System

    International Nuclear Information System (INIS)

    Herndon, J.N.; Martin, H.L.; Satterlee, P.E. Jr.; Jelatis, D.G.; Jennrich, C.E.

    1984-04-01

    The Model M-2 Maintenance System is part of an ongoing program within the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) to improve remote manipulation technology for future nuclear fuel reprocessing and other remote applications. Techniques, equipment, and guidelines which can improve the efficiency of remote maintenance are being developed. The Model M-2 Maintenance System, installed in the Integrated Equipment Test (IET) Facility at ORNL, provides a complete, integrated remote maintenance system for the demonstration and development of remote maintenance techniques. The system comprises a pair of force-reflecting servomanipulator arms, television viewing, lighting, and auxiliary lifting capabilities, thereby allowing manlike maintenance operations to be executed remotely within the remote cell mockup area in the IET. The Model M-2 Maintenance System incorporates an upgraded version of the proven Central Research Laboratories' Model M servomanipulator. Included are state-of-the-art brushless dc servomotors for improved performance, remotely removable wrist assemblies, geared azimuth drive, and a distributed microprocessor-based digital control system. 5 references, 8 figures

  10. Dynamic modeling and simulation of power transformer maintenance costs

    Directory of Open Access Journals (Sweden)

    Ristić Olga

    2016-01-01

    Full Text Available The paper presents the dynamic model of maintenance costs of the power transformer functional components. Reliability is modeled combining the exponential and Weibull's distribution. The simulation was performed with the aim of corrective maintenance and installation of the continuous monitoring system of the most critical components. Simulation Dynamic System (SDS method and VENSIM PLE software was used to simulate the cost. In this way, significant savings in maintenance costs will be achieved with a small initial investment. [Projekat Ministarstva nauke Republike Srbije, br. III 41025 i br. OI 171007

  11. Optimization of maintenance policy using the proportional hazard model

    Energy Technology Data Exchange (ETDEWEB)

    Samrout, M. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: mohamad.el_samrout@utt.fr; Chatelet, E. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: chatelt@utt.fr; Kouta, R. [M3M Laboratory, University of Technology of Belfort Montbeliard (France); Chebbo, N. [Industrial Systems Laboratory, IUT, Lebanese University (Lebanon)

    2009-01-15

    The evolution of system reliability depends on its structure as well as on the evolution of its components reliability. The latter is a function of component age during a system's operating life. Component aging is strongly affected by maintenance activities performed on the system. In this work, we consider two categories of maintenance activities: corrective maintenance (CM) and preventive maintenance (PM). Maintenance actions are characterized by their ability to reduce this age. PM consists of actions applied on components while they are operating, whereas CM actions occur when the component breaks down. In this paper, we expound a new method to integrate the effect of CM while planning for the PM policy. The proportional hazard function was used as a modeling tool for that purpose. Interesting results were obtained when comparison between policies that take into consideration the CM effect and those that do not is established.

  12. Modeling of the maintenance policy of an offshore wind farm

    International Nuclear Information System (INIS)

    Maddens, L.; Labeau, P.E.

    2004-01-01

    Wind energy has a key position in the market of renewable electricity production means. Offshore wind farms offer additional surfaces to exploit this form of energy, together with more favourable wind conditions. Yet offshore windmills ask for higher investment and maintenance costs. Optimising the latter costs should therefore turn out to be particularly beneficial for this technology. The present paper summarizes the main modelling aspects of the maintenance of a typical offshore wind farm, such as the accessibility of the wind turbines and the impact of weather conditions, the cost of the different transport resources, the number of maintenance teams, a tolerated unavailability of part of the windmills, the opportunity to combine corrective and preventive maintenance actions on one or several windmills. All these features were embedded in a Petri net model of the maintenance policy of the farm, allowing to estimate the maintenance costs entailed by several strategies. Advantages and drawbacks of using Petri nets for the modelling of such a maintenance strategy are finally discussed. (authors)

  13. Advanced Ground Systems Maintenance Physics Models For Diagnostics Project

    Science.gov (United States)

    Perotti, Jose M.

    2015-01-01

    The project will use high-fidelity physics models and simulations to simulate real-time operations of cryogenic and systems and calculate the status/health of the systems. The project enables the delivery of system health advisories to ground system operators. The capability will also be used to conduct planning and analysis of cryogenic system operations. This project will develop and implement high-fidelity physics-based modeling techniques tosimulate the real-time operation of cryogenics and other fluids systems and, when compared to thereal-time operation of the actual systems, provide assessment of their state. Physics-modelcalculated measurements (called “pseudo-sensors”) will be compared to the system real-timedata. Comparison results will be utilized to provide systems operators with enhanced monitoring ofsystems' health and status, identify off-nominal trends and diagnose system/component failures.This capability can also be used to conduct planning and analysis of cryogenics and other fluidsystems designs. This capability will be interfaced with the ground operations command andcontrol system as a part of the Advanced Ground Systems Maintenance (AGSM) project to helpassure system availability and mission success. The initial capability will be developed for theLiquid Oxygen (LO2) ground loading systems.

  14. The road maintenance funding models in Indonesia use earmarked tax

    Science.gov (United States)

    Gultom, Tiopan Henry M.; Tamin, Ofyar Z.; Sjafruddin, Ade; Pradono

    2017-11-01

    One of the solutions to get a sustainable road maintenance fund is to separate road sector revenue from other accounts, afterward, form a specific account for road maintenance. In 2001, Antameng and the Ministry of Public Works proposed a road fund model in Indonesia. Sources of the road funds proposal was a tariff formed on the nominal total tax. The policy of road funds was proposed to finance the road network maintenance of districts and provincials. This research aims to create a policy model of road maintenance funds in Indonesia using an earmarked tax mechanism. The research method is qualitative research, with data collection techniques are triangulation. Interview methods conducted were semi-structured. Strength, Weakness, Opportunities, and Threat from every part of the models were showen on the survey format. Respondents were representative of executives who involved directly against the financing of road maintenance. Validation model conducted by a discussion panel, it was called the Focus Group Discussion (FGD). The FGD involved all selected respondents. Road maintenance financing model that most appropriately applied in Indonesia was a model of revenue source use an earmarked PBBKB, PKB and PPnBM. Revenue collection mechanism was added tariff of registered vehicle tax (PKB), Vehicle Fuel Tax (PBBKB) and the luxury vehicle sales tax (PPnBM). The funds are managed at the provincial level by a public service agency.

  15. Pavement maintenance optimization model using Markov Decision Processes

    Science.gov (United States)

    Mandiartha, P.; Duffield, C. F.; Razelan, I. S. b. M.; Ismail, A. b. H.

    2017-09-01

    This paper presents an optimization model for selection of pavement maintenance intervention using a theory of Markov Decision Processes (MDP). There are some particular characteristics of the MDP developed in this paper which distinguish it from other similar studies or optimization models intended for pavement maintenance policy development. These unique characteristics include a direct inclusion of constraints into the formulation of MDP, the use of an average cost method of MDP, and the policy development process based on the dual linear programming solution. The limited information or discussions that are available on these matters in terms of stochastic based optimization model in road network management motivates this study. This paper uses a data set acquired from road authorities of state of Victoria, Australia, to test the model and recommends steps in the computation of MDP based stochastic optimization model, leading to the development of optimum pavement maintenance policy.

  16. A Compromise Programming Model for Highway Maintenance Resources Allocation Problem

    Directory of Open Access Journals (Sweden)

    Hui Xiong

    2012-01-01

    Full Text Available This paper formulates a bilevel compromise programming model for allocating resources between pavement and bridge deck maintenances. The first level of the model aims to solve the resource allocation problems for pavement management and bridge deck maintenance, without considering resource sharing between them. At the second level, the model uses the results from the first step as an input and generates the final solution to the resource-sharing problem. To solve the model, the paper applies genetic algorithms to search for the optimal solution. We use a combination of two digits to represent different maintenance types. Results of numerical examples show that the conditions of both pavements and bridge decks are improved significantly by applying compromise programming, rather than conventional methods. Resources are also utilized more efficiently when the proposed method is applied.

  17. AN OPTIMAL MAINTENANCE MANAGEMENT MODEL FOR AIRPORT CONCRETE PAVEMENT

    Science.gov (United States)

    Shimomura, Taizo; Fujimori, Yuji; Kaito, Kiyoyuki; Obama, Kengo; Kobayashi, Kiyoshi

    In this paper, an optimal management model is formulated for the performance-based rehabilitation/maintenance contract for airport concrete pavement, whereby two types of life cycle cost risks, i.e., ground consolidation risk and concrete depreciation risk, are explicitly considered. The non-homogenous Markov chain model is formulated to represent the deterioration processes of concrete pavement which are conditional upon the ground consolidation processes. The optimal non-homogenous Markov decision model with multiple types of risk is presented to design the optimal rehabilitation/maintenance plans. And the methodology to revise the optimal rehabilitation/maintenance plans based upon the monitoring data by the Bayesian up-to-dating rules. The validity of the methodology presented in this paper is examined based upon the case studies carried out for the H airport.

  18. Basic study of the plant maintenance model considering plant improvement/modification

    International Nuclear Information System (INIS)

    Tsumaya, Akira; Inoue, Kazuya; Mochizuki, Masahito; Wakamatsu, Hidefumi; Arai, Eiji

    2007-01-01

    This paper proposes a maintenance activity model that considers not only routine maintenance activity but also functional maintenance including improvement/modification. Required maintenance types are categorized, and limitation of Activity Domain Integration Diagram (ADID) proposed by ISO18435 are discussed based on framework for life cycle maintenance management of manufacturing assets. Then, we proposed extension ADID model for plant maintenance activity model considering functional improvement/modification. (author)

  19. Statistical inference for imperfect maintenance models with missing data

    International Nuclear Information System (INIS)

    Dijoux, Yann; Fouladirad, Mitra; Nguyen, Dinh Tuan

    2016-01-01

    The paper considers complex industrial systems with incomplete maintenance history. A corrective maintenance is performed after the occurrence of a failure and its efficiency is assumed to be imperfect. In maintenance analysis, the databases are not necessarily complete. Specifically, the observations are assumed to be window-censored. This situation arises relatively frequently after the purchase of a second-hand unit or in the absence of maintenance record during the burn-in phase. The joint assessment of the wear-out of the system and the maintenance efficiency is investigated under missing data. A review along with extensions of statistical inference procedures from an observation window are proposed in the case of perfect and minimal repair using the renewal and Poisson theories, respectively. Virtual age models are employed to model imperfect repair. In this framework, new estimation procedures are developed. In particular, maximum likelihood estimation methods are derived for the most classical virtual age models. The benefits of the new estimation procedures are highlighted by numerical simulations and an application to a real data set. - Highlights: • New estimation procedures for window-censored observations and imperfect repair. • Extensions of inference methods for perfect and minimal repair with missing data. • Overview of maximum likelihood method with complete and incomplete observations. • Benefits of the new procedures highlighted by simulation studies and real application.

  20. The health maintenance organization strategy: a corporate takeover of health services delivery.

    Science.gov (United States)

    Salmon, J W

    1975-01-01

    This paper presents a political economic framework for viewing the social organization of the delivery of health care servies and predicting a qualitatively different institutional configuration involving the health maintenance organization. The principal forces impacting American capitalism today are leading to a fundamental restructuring for increased social efficiency of the entire social welfare sector, including the health services industry. The method to achieve this restructuring involves health policy directed at raising the contribution to the social surplus from the delivery of health care services and eventual corporate domination. The health maintenance organization conceptualization is examined with suggestions as to how the HMO strategy promoted by the state leads to this corporate takeover. The mechanism and extent of the present corporate involvement are examined and implications of health services as a social control mechanism are presented.

  1. A multi-criteria model for maintenance job scheduling

    Directory of Open Access Journals (Sweden)

    Sunday A. Oke

    2007-12-01

    Full Text Available This paper presents a multi-criteria maintenance job scheduling model, which is formulated using a weighted multi-criteria integer linear programming maintenance scheduling framework. Three criteria, which have direct relationship with the primary objectives of a typical production setting, were used. These criteria are namely minimization of equipment idle time, manpower idle time and lateness of job with unit parity. The mathematical model constrained by available equipment, manpower and job available time within planning horizon was tested with a 10-job, 8-hour time horizon problem with declared equipment and manpower available as against the required. The results, analysis and illustrations justify multi-criteria consideration. Thus, maintenance managers are equipped with a tool for adequate decision making that guides against error in the accumulated data which may lead to wrong decision making. The idea presented is new since it provides an approach that has not been documented previously in the literature.

  2. The Science of Sustaining Health Behavior Change: The Health Maintenance Consortium

    Science.gov (United States)

    Ory, Marcia G.; Smith, Matthew Lee; Mier, Nelda; Wernicke, Meghan M.

    2013-01-01

    Objective The Health Maintenance Consortium (HMC) is a multisite Grantee Consortium funded by the National Institutes of Health from 2004–2009. The goal of HMC is to enhance understanding of the long-term maintenance of behavior change, as well as effective strategies for achieving sustainable health promotion and disease prevention. Methods This introductory research synthesis prepared by the Resource Center gives context to this theme issue by providing an overview of the HMC and the articles in this journal. Results It explores the contributions to our conceptualization of behavior change processes and intervention strategies, the trajectory of effectiveness of behavioral and social interventions, and factors influencing the long-term maintenance of behavioral and social interventions. Conclusions Future directions for furthering the science of maintaining behavior change and reducing the gaps between research and practice are recommended. PMID:20604691

  3. Mobile Healthcare Applications and Gamification for Sustained Health Maintenance

    Directory of Open Access Journals (Sweden)

    Changjun Lee

    2017-05-01

    Full Text Available This paper examines how gamification affects user intention to use mobile healthcare applications (mHealth and how the effect of gamification works differently according to health status, age, and gender. We use data from a mobile survey conducted by a Korean representative survey agency. We estimate the effect of gamification on user intention to use mobile healthcare applications based on a structural equation model and examine the moderating effects of self-reported health status, age, and gender. We find that gamification is effective in increasing user intention to use mHealth, especially in the healthy and younger groups. These findings suggest that mHealth, with the gamification factor, would encourage healthy (but lack exercise people as well as unhealthy people to maintain their health status, and thus the mHealth developers need to consider the gamification factor when they develop mHealth services for healthy people.

  4. A Predictive Maintenance Model for Railway Tracks

    DEFF Research Database (Denmark)

    Li, Rui; Wen, Min; Salling, Kim Bang

    2015-01-01

    presents a mathematical model based on Mixed Integer Programming (MIP) which is designed to optimize the predictive railway tamping activities for ballasted track for the time horizon up to four years. The objective function is setup to minimize the actual costs for the tamping machine (measured by time......). Five technical and economic aspects are taken into account to schedule tamping: (1) track degradation of the standard deviation of the longitudinal level over time; (2) track geometrical alignment; (3) track quality thresholds based on the train speed limits; (4) the dependency of the track quality...

  5. Health and Maintenance Status Determination and Predictive Fault Diagnosis System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project is to demonstrate intelligent health and maintenance status determination and predictive fault diagnosis techniques for NASA rocket...

  6. Social Health Maintenance Organizations: assessing their initial experience.

    Science.gov (United States)

    Newcomer, R; Harrington, C; Friedlob, A

    1990-08-01

    The Social/Health Maintenance Organization (S/HMO) is a four-site national demonstration. This program combines Medicare Part A and B coverage, with various extended and chronic care benefits, into an integrated health plan. The provision of these services extends both the traditional roles of HMOs and that of long-term care community-service case management systems. During the initial 30 months of operation the four S/HMOs shared financial risk with the Health Care Financing Administration. This article reports on this developmental period. During this phase the S/HMOs had lower-than-expected enrollment levels due in part to market competition, underfunding of marketing efforts, the limited geographic area served, and an inability to differentiate the S/HMO product from that of other Medicare HMOs. The S/HMOs were allowed to conduct health screening of applicants prior to enrolling them. The number of nursing home-certifiable enrollees was controlled through this mechanism, but waiting lists were never very long. Persons joining S/HMOs and other Medicare HMOs during this period were generally aware of the alternatives available. S/HMO enrollees favored the more extensive benefits; HMO enrollees considerations of cost. The S/HMOs compare both newly formed HMOs and established HMOs. On the basis of administrator cost, it is more efficient to add chronic care benefits to an HMO than to add an HMO component to a community care provider. All plans had expenses greater than their revenues during the start-up period, but they were generally able to keep service expenditures within planned levels.

  7. Segmenting health maintenance organizations to study productivity and profitability.

    Science.gov (United States)

    Sobol, M G

    2000-01-01

    As the decade ended, health maintenance organizations (HMOs) were increasing in popularity as a means of health care delivery. These groups take many forms, so it is important for the analyst to see if the efficiency and financial results for these different forms vary. The four major forms are profit vs. not-for-profit, chain vs. non-chain, group/staff vs. individual practice association (IPA), and federally qualified vs. non-federally qualified. Using a nationwide database of all the HMOs in the United States, the article compares liquidity rates, leverage ratios, profitability ratios, marketing, and per member ratios across the four groups using paired t tests. The two classifications that showed the most differences were group/staff vs. IPA and federally qualified vs. non-federally qualified. IPAs have a better liquidity position and lower leverage ratios than group/staff but their administrative costs are higher and the time to receive payments and to pay debts is higher. Non-federally qualified have somewhat higher liquidity ratios and higher profitability ratios. These significant differences in financial outcomes indicate that studies of HMOs should segment different major forms of organizations and study them separately before trying to show the effects of different policies on HMO efficiency and effectiveness.

  8. Financial risk sharing with providers in health maintenance organizations, 1999.

    Science.gov (United States)

    Gold, Marsha R; Lake, Timothy; Hurley, Robert; Sinclair, Michael

    2002-01-01

    The transfer of financial risk from health maintenance organizations (HMOs) to providers is controversial. To provide timely national data on these practices, we conducted a telephone survey in 1999 of a multi-staged probability sample of HMOs in 20 of the nation's 60 largest markets, accounting for 86% of all HMO enrollees nationally. Among those sampled, 82% responded. We found that HMOs' provider networks with physicians, hospitals, skilled nursing homes, and home health agencies are complex and multi-tiered Seventy-six percent of HMOs in our study use contracts for their HMO products that involve global, professional services, or hospital risk capitation to intermediate entities. These arrangements account for between 24.5 million and 27.4 million of the 55.9 million commercial and Medicare HMO enrollees in the 60 largest markets. While capitation arrangements are particularly common in California, they are more common elsewhere than many assume. The complex layering of risk sharing and delegation of care management responsibility raise questions about accountability and administrative costs in managed care. Do complex structures provide a way to involve providers more directly in managed care, or do they diffuse authority and add to administrative costs?

  9. On the application of copula in modeling maintenance contract

    International Nuclear Information System (INIS)

    Iskandar, B P; Husniah, H

    2016-01-01

    This paper deals with the application of copula in maintenance contracts for a nonrepayable item. Failures of the item are modeled using a two dimensional approach where age and usage of the item and this requires a bi-variate distribution to modelling failures. When the item fails then corrective maintenance (CM) is minimally repaired. CM can be outsourced to an external agent or done in house. The decision problem for the owner is to find the maximum total profit whilst for the agent is to determine the optimal price of the contract. We obtain the mathematical models of the decision problems for the owner as well as the agent using a Nash game theory formulation. (paper)

  10. Wind turbine blade life-time assessment model for preventive planning of operation and maintenance

    DEFF Research Database (Denmark)

    Florian, Mihai; Sørensen, John Dalsgaard

    2014-01-01

    Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M) practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair...... of information on the blades structural health to the decision maker. Further, inspections of the blades are often performed in connection with service. In light of the obtained information, a preventive type of maintenance becomes feasible, with the potential of predicting the blades remaining life to support O......&M decisions for avoiding major failure events. The present paper presents a fracture mechanics based model for estimating the remaining life of a wind turbine blade, focusing on the crack propagation in the blades adhesive joints. A generic crack propagation model is built in Matlab based on a Paris law...

  11. Wind Turbine Blade Life-Time Assessment Model for Preventive Planning of Operation and Maintenance

    DEFF Research Database (Denmark)

    Florian, Mihai; Sørensen, John Dalsgaard

    2015-01-01

    Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M) practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair...... of information on the blades structural health to the decision maker. Further, inspections of the blades are often performed in connection with service. In light of the obtained information, a preventive type of maintenance becomes feasible, with the potential of predicting the blades remaining life to support O......&M decisions for avoiding major failure events. The present paper presents a fracture mechanics based model for estimating the remaining life of a wind turbine blade, focusing on the crack propagation in the blades adhesive joints. A generic crack propagation model is built in Matlab based on a Paris law...

  12. Survey of relationship between spiritual health and mental health in patients undergoing methadone maintenance treatment (MMT

    Directory of Open Access Journals (Sweden)

    abolhassan naghibi

    2015-12-01

    Full Text Available Introduction and goal: Religiosity and spirituality decreasesof the impact of life stress on the tendency to substance use. Everyday addedto the number of people who believe that spirituality is the way to treat neuroses and mental problems. This study aimed to determine the relationship between spiritual health and mental health in patients undergoing to methadone maintenance treatment (MMT dependent on the private and government sector in Sari. Method: This study was cross- sectional study. The target populations of this study were 123 women and men undergoing to methadone maintenance treatment (MMT. The data collected by spiritual and mental health questionnaire and were analyzed using two-sample t-test and spearman correlationin theSPSS (18 software. Findings: The grade average of spiritual health was 43/29 and mental health was 41/26.The results showed that a significant correlation between spiritual health with mental health. The highest correlation was between spiritual healthwith the social function and the lowestcorrelation was with physical problems. There was no significant relationshipbetween of marital status, number of children, sex and spiritual health. Conclusion: According to positive and significant role spiritual health in mental health, so, strengthen the spiritual dimension can to promote mental health and reduce mental disorders and the tendency to addiction.

  13. Ageing model considering effects of maintenance and working conditions

    International Nuclear Information System (INIS)

    Martorell, S.; Sanchez, A.; Serradell, V.

    1998-01-01

    Nowadays, there is some doubt about building new Nuclear Power Plants (NPPs). Instead, there is a growing interest in analyzing the possibility to extend current NPP operation where life management programs play an important role. The evolution of the NPP safety depends on the evolution of the reliability of its safety components as a function of their age along the NPP operational life. In this paper, a new age-dependent reliability model is presented, which includes parameters related to surveillance and maintenance effectiveness and working conditions, both environmental and operational, of the equipment. This model may be used to support NPP life management and life extension programs by improving or optimizing surveillance and maintenance tasks using risk and cost models based on such an age-dependent reliability model. The results of the sensitivity study in the application show that the selection of the most appropriate maintenance strategy would directly depend on the previous parameters and very important differences are expected to appear under certain circumstance. (Author) 7 refs

  14. Wind Turbine Blade Life-Time Assessment Model for Preventive Planning of Operation and Maintenance

    Directory of Open Access Journals (Sweden)

    Mihai Florian

    2015-09-01

    Full Text Available Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair and replacement activities as well as large revenue losses, mainly in the case of offshore wind farms. The recent development and evolution of condition monitoring techniques, as well as the fact that an increasing number of installed turbines are equipped with online monitoring systems, offers a large amount of information on the blades structural health to the decision maker. Further, inspections of the blades are often performed in connection with service. In light of the obtained information, a preventive type of maintenance becomes feasible, with the potential of predicting the blades remaining life to support O&M decisions for avoiding major failure events. The present paper presents a fracture mechanics based model for estimating the remaining life of a wind turbine blade, focusing on the crack propagation in the blades adhesive joints. A generic crack propagation model is built in Matlab based on a Paris law approach. The model is used within a risk-based maintenance decision framework to optimize maintenance planning for the blades lifetime.

  15. Impacts of building information modeling on facility maintenance management

    Energy Technology Data Exchange (ETDEWEB)

    Ahamed, Shafee; Neelamkavil, Joseph; Canas, Roberto [Centre for Computer-assisted Construction Technologies, National Research Council of Canada, London, Ontario (Canada)

    2010-07-01

    Building information modeling (BIM) is a digital representation of the physical and functional properties of a building; it has been used by construction professionals for a long time and stakeholders are now using it in different aspects of the building lifecycle. This paper intends to present how BIM impacts the construction industry and how it can be used for facility maintenance management. The maintenance and operations of buildings are in most cases still managed through the use of drawings and spreadsheets although life cycle costs of a building are significantly higher than initial investment costs; thus, the use of BIM could help in achieving a higher efficiency and so important benefits. This study is part of an ongoing research project, the nD modeling project, which aims at predicting building energy consumption with better accuracy.

  16. Service Life and Maintenance Modelling of Reinforced Concrete Bridge Decks

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Recent research in the area of assessment and maintenance of reinforced concrete bridge decks is presented in this paper. Three definitions of service lifetime are introduced and the difficult problem of assessing the service life is discussed. A stochastic modelling of corrosion and corrosion...... cracking is introduced and the site dependency of corrosion is stressed. Finally, a recently developed optimal repair strategy for bridges is briefly explained....

  17. Modeling of preventive maintenance changes influence upon flight safety indexes

    Directory of Open Access Journals (Sweden)

    А.В. Гончаренко

    2004-03-01

    Full Text Available  It is considered a simplified model of connection between the catastrophic events flow frequency and both preventive maintenance changes periodicity and diagnosis depth of aviation equipment. It is deduced specific formulas for computing the changes and diagnostics parameters influence upon the values of both the catastrophic events flow frequency and technical-economical control factor criterion of flight safety levels.

  18. Neural Networks in Modelling Maintenance Unit Load Status

    Directory of Open Access Journals (Sweden)

    Anđelko Vojvoda

    2002-03-01

    Full Text Available This paper deals with a way of applying a neural networkfor describing se1vice station load in a maintenance unit. Dataacquired by measuring the workload of single stations in amaintenance unit were used in the process of training the neuralnetwork in order to create a model of the obse1ved system.The model developed in this way enables us to make more accuratepredictions over critical overload. Modelling was realisedby developing and using m-functions of the Matlab software.

  19. Degradation modeling with application to aging and maintenance effectiveness evaluations

    International Nuclear Information System (INIS)

    Samanta, P.K.; Hsu, F.; Subduhi, M.; Vesely, W.E.

    1990-01-01

    This paper describes a modeling approach to analyze component degradation and failure data to understand the aging process of components. As used here, degradation modeling is the analysis of information on component degradation in order to develop models of the process and its implications. This particular modeling focuses on the analysis of the times of component degradations, to model how the rate of degradation changes with the age of the component. The methodology presented also discusses the effectiveness of maintenance as applicable to aging evaluations. The specific applications which are performed show quantitative models of component degradation rates and component failure rates from plant-specific data. The statistical techniques which are developed and applied allow aging trends to be effectively identified in the degradation data, and in the failure data. Initial estimates of the effectiveness of maintenance in limiting degradations from becoming failures also are developed. These results are important first steps in degradation modeling, and show that degradation can be modeled to identify aging trends. 2 refs., 8 figs

  20. Degradation modeling with application to aging and maintenance effectiveness evaluations

    International Nuclear Information System (INIS)

    Samanta, P.K.; Vesely, W.E.; Hsu, F.; Subudhi, M.

    1991-01-01

    This paper describes a modeling approach to analyze light water reactor component degradation and failure data to understand the aging process of components. As used here, degradation modeling is the analysis of information on component degradation in order to develop models of the process and its implications. This particular modeling focuses on the analysis of the times of component degradations, to model how the rate of degradation changes with the age of the component. The methodology presented also discusses the effectiveness of maintenance as applicable to aging evaluations. The specific applications which are performed show quantitative models of component degradation rates and component failure rates from plant-specific data. The statistical techniques which are developed and applied allow aging trends to be effectively identified in the degradation data, and in the failure data. Initial estimates of the effectiveness of maintenance in limiting degradations from becoming failures also are developed. These results are important first steps in degradation modeling, and show that degradation can be modeled to identify aging trends

  1. Fuzzy Goal Programming Approach in Selective Maintenance Reliability Model

    Directory of Open Access Journals (Sweden)

    Neha Gupta

    2013-12-01

    Full Text Available 800x600 In the present paper, we have considered the allocation problem of repairable components for a parallel-series system as a multi-objective optimization problem and have discussed two different models. In first model the reliability of subsystems are considered as different objectives. In second model the cost and time spent on repairing the components are considered as two different objectives. These two models is formulated as multi-objective Nonlinear Programming Problem (MONLPP and a Fuzzy goal programming method is used to work out the compromise allocation in multi-objective selective maintenance reliability model in which we define the membership functions of each objective function and then transform membership functions into equivalent linear membership functions by first order Taylor series and finally by forming a fuzzy goal programming model obtain a desired compromise allocation of maintenance components. A numerical example is also worked out to illustrate the computational details of the method.  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

  2. A genetic algorithm solution for a nuclear power plant risk-cost maintenance model

    International Nuclear Information System (INIS)

    Tong Jiejuan; Mao Dingyuan; Xue Dazhi

    2004-01-01

    Reliability Centered Maintenance (RCM) is one of the popular maintenance optimization methods according to certain kinds of priorities. Traditional RCM usually analyzes and optimizes the maintenance strategy from the viewpoint of component instead of the whole maintenance program impact. Research presented in this paper is a pilot study using PSA techniques in RCM. How to reflect the effect on component unavailability by the maintenance activities such as surveillance testing and preventive maintenance in PSA model is discussed firstly. Based on the discussion, a maintenance risk-cost model is established for global maintenance optimization in a nuclear power plant, and a genetic algorithm (GA) is applied to solve such a model to get the global optimized maintenance strategy. Finally, the result got from a simple test case based on a risk-cost model consisting of 10 components is presented

  3. Maintenance personnel performance simulation (MAPPS) model: overview and evaluation efforts

    International Nuclear Information System (INIS)

    Knee, H.E.; Haas, P.M.; Siegel, A.I.; Bartter, W.D.; Wolf, J.J.; Ryan, T.G.

    1984-01-01

    The development of the MAPPS model has been completed and the model is currently undergoing evaluation. These efforts are addressing a number of identified issues concerning practicality, acceptability, usefulness, and validity. Preliminary analysis of the evaluation data that has been collected indicates that MAPPS will provide comprehensive and reliable data for PRA purposes and for a number of other applications. The MAPPS computer simulation model provides the user with a sophisticated tool for gaining insights into tasks performed by NPP maintenance personnel. Its wide variety of input parameters and output data makes it extremely flexible for application to a number of diverse applications. With the demonstration of favorable model evaluation results, the MAPPS model will represent a valuable source of NPP maintainer reliability data and provide PRA studies with a source of data on maintainers that has previously not existed

  4. A model for preemptive maintenance of medical linear accelerators—predictive maintenance

    International Nuclear Information System (INIS)

    Able, Charles M.; Baydush, Alan H.; Nguyen, Callistus; Gersh, Jacob; Ndlovu, Alois; Rebo, Igor; Booth, Jeremy; Perez, Mario; Sintay, Benjamin; Munley, Michael T.

    2016-01-01

    Unscheduled accelerator downtime can negatively impact the quality of life of patients during their struggle against cancer. Currently digital data accumulated in the accelerator system is not being exploited in a systematic manner to assist in more efficient deployment of service engineering resources. The purpose of this study is to develop an effective process for detecting unexpected deviations in accelerator system operating parameters and/or performance that predicts component failure or system dysfunction and allows maintenance to be performed prior to the actuation of interlocks. The proposed predictive maintenance (PdM) model is as follows: 1) deliver a daily quality assurance (QA) treatment; 2) automatically transfer and interrogate the resulting log files; 3) once baselines are established, subject daily operating and performance values to statistical process control (SPC) analysis; 4) determine if any alarms have been triggered; and 5) alert facility and system service engineers. A robust volumetric modulated arc QA treatment is delivered to establish mean operating values and perform continuous sampling and monitoring using SPC methodology. Chart limits are calculated using a hybrid technique that includes the use of the standard SPC 3σ limits and an empirical factor based on the parameter/system specification. There are 7 accelerators currently under active surveillance. Currently 45 parameters plus each MLC leaf (120) are analyzed using Individual and Moving Range (I/MR) charts. The initial warning and alarm rule is as follows: warning (2 out of 3 consecutive values ≥ 2σ hybrid ) and alarm (2 out of 3 consecutive values or 3 out of 5 consecutive values ≥ 3σ hybrid ). A customized graphical user interface provides a means to review the SPC charts for each parameter and a visual color code to alert the reviewer of parameter status. Forty-five synthetic errors/changes were introduced to test the effectiveness of our initial chart limits. Forty

  5. A model for preemptive maintenance of medical linear accelerators-predictive maintenance.

    Science.gov (United States)

    Able, Charles M; Baydush, Alan H; Nguyen, Callistus; Gersh, Jacob; Ndlovu, Alois; Rebo, Igor; Booth, Jeremy; Perez, Mario; Sintay, Benjamin; Munley, Michael T

    2016-03-10

    Unscheduled accelerator downtime can negatively impact the quality of life of patients during their struggle against cancer. Currently digital data accumulated in the accelerator system is not being exploited in a systematic manner to assist in more efficient deployment of service engineering resources. The purpose of this study is to develop an effective process for detecting unexpected deviations in accelerator system operating parameters and/or performance that predicts component failure or system dysfunction and allows maintenance to be performed prior to the actuation of interlocks. The proposed predictive maintenance (PdM) model is as follows: 1) deliver a daily quality assurance (QA) treatment; 2) automatically transfer and interrogate the resulting log files; 3) once baselines are established, subject daily operating and performance values to statistical process control (SPC) analysis; 4) determine if any alarms have been triggered; and 5) alert facility and system service engineers. A robust volumetric modulated arc QA treatment is delivered to establish mean operating values and perform continuous sampling and monitoring using SPC methodology. Chart limits are calculated using a hybrid technique that includes the use of the standard SPC 3σ limits and an empirical factor based on the parameter/system specification. There are 7 accelerators currently under active surveillance. Currently 45 parameters plus each MLC leaf (120) are analyzed using Individual and Moving Range (I/MR) charts. The initial warning and alarm rule is as follows: warning (2 out of 3 consecutive values ≥ 2σ hybrid) and alarm (2 out of 3 consecutive values or 3 out of 5 consecutive values ≥ 3σ hybrid). A customized graphical user interface provides a means to review the SPC charts for each parameter and a visual color code to alert the reviewer of parameter status. Forty-five synthetic errors/changes were introduced to test the effectiveness of our initial chart limits. Forty

  6. Hidden Semi-Markov Models for Predictive Maintenance

    Directory of Open Access Journals (Sweden)

    Francesco Cartella

    2015-01-01

    Full Text Available Realistic predictive maintenance approaches are essential for condition monitoring and predictive maintenance of industrial machines. In this work, we propose Hidden Semi-Markov Models (HSMMs with (i no constraints on the state duration density function and (ii being applied to continuous or discrete observation. To deal with such a type of HSMM, we also propose modifications to the learning, inference, and prediction algorithms. Finally, automatic model selection has been made possible using the Akaike Information Criterion. This paper describes the theoretical formalization of the model as well as several experiments performed on simulated and real data with the aim of methodology validation. In all performed experiments, the model is able to correctly estimate the current state and to effectively predict the time to a predefined event with a low overall average absolute error. As a consequence, its applicability to real world settings can be beneficial, especially where in real time the Remaining Useful Lifetime (RUL of the machine is calculated.

  7. Maintenance Personnel Performance Simulation (MAPPS) model: description of model content, structure, and sensitivity testing. Volume 2

    International Nuclear Information System (INIS)

    Siegel, A.I.; Bartter, W.D.; Wolf, J.J.; Knee, H.E.

    1984-12-01

    This volume of NUREG/CR-3626 presents details of the content, structure, and sensitivity testing of the Maintenance Personnel Performance Simulation (MAPPS) model that was described in summary in volume one of this report. The MAPPS model is a generalized stochastic computer simulation model developed to simulate the performance of maintenance personnel in nuclear power plants. The MAPPS model considers workplace, maintenance technician, motivation, human factors, and task oriented variables to yield predictive information about the effects of these variables on successful maintenance task performance. All major model variables are discussed in detail and their implementation and interactive effects are outlined. The model was examined for disqualifying defects from a number of viewpoints, including sensitivity testing. This examination led to the identification of some minor recalibration efforts which were carried out. These positive results indicate that MAPPS is ready for initial and controlled applications which are in conformity with its purposes

  8. Environmental Management Model for Road Maintenance Operation Involving Community Participation

    Science.gov (United States)

    Triyono, A. R. H.; Setyawan, A.; Sobriyah; Setiono, P.

    2017-07-01

    Public expectations of Central Java, which is very high on demand fulfillment, especially road infrastructure as outlined in the number of complaints and community expectations tweeter, Short Mail Massage (SMS), e-mail and public reports from various media, Highways Department of Central Java province requires development model of environmental management in the implementation of a routine way by involving the community in order to fulfill the conditions of a representative, may serve road users safely and comfortably. This study used survey method with SEM analysis and SWOT with Latent Independent Variable (X), namely; Public Participation in the regulation, development, construction and supervision of road (PSM); Public behavior in the utilization of the road (PMJ) Provincial Road Service (PJP); Safety in the Provincial Road (KJP); Integrated Management System (SMT) and latent dependent variable (Y) routine maintenance of the provincial road that is integrated with the environmental management system and involve the participation of the community (MML). The result showed the implementation of routine maintenance of road conditions in Central Java province has yet to implement an environmental management by involving the community; Therefore developed environmental management model with the results of H1: Community Participation (PSM) has positive influence on the Model of Environmental Management (MML); H2: Behavior Society in Jalan Utilization (PMJ) positive effect on Model Environmental Management (MML); H3: Provincial Road Service (PJP) positive effect on Model Environmental Management (MML); H4: Safety in the Provincial Road (KJP) positive effect on Model Environmental Management (MML); H5: Integrated Management System (SMT) has positive influence on the Model of Environmental Management (MML). From the analysis obtained formulation model describing the relationship / influence of the independent variables PSM, PMJ, PJP, KJP, and SMT on the dependent variable

  9. Low-complexity Behavioral Model for Predictive Maintenance of Railway Turnouts

    DEFF Research Database (Denmark)

    Barkhordari, Pegah; Galeazzi, Roberto; Tejada, Alejandro de Miguel

    2017-01-01

    together with the Eigensystem Realization Algorithm – a type of subspace identification – to identify a fourth order model of the infrastructure. The robustness and predictive capability of the low-complexity behavioral model to reproduce track responses under different types of train excitations have been......Maintenance of railway infrastructures represents a major cost driver for any infrastructure manager since reliability and dependability must be guaranteed at all times. Implementation of predictive maintenance policies relies on the availability of condition monitoring systems able to assess...... the infrastructure health state. The core of any condition monitoring system is the a-priori knowledge about the process to be monitored, in the form of either mathematical models of different complexity or signal features characterizing the healthy/faulty behavior. This study investigates the identification...

  10. Planning and control of maintenance systems modelling and analysis

    CERN Document Server

    Duffuaa, Salih O

    2015-01-01

    Analyzing maintenance as an integrated system with objectives, strategies and processes that need to be planned, designed, engineered, and controlled using statistical and optimization techniques, the theme of this book is the strategic holistic system approach for maintenance. This approach enables maintenance decision makers to view maintenance as a provider of a competitive edge not a necessary evil. Encompassing maintenance systems; maintenance strategic and capacity planning, planned and preventive maintenance, work measurements and standards, material (spares) control, maintenance operations and control, planning and scheduling, maintenance quality, training, and others, this book gives readers an understanding of the relevant methodology and how to apply it to real-world problems in industry. Each chapter includes a number exercises and is suitable as a textbook or a reference for a professionals and practitioners whilst being of interest to industrial engineering, mechanical engineering, electrical en...

  11. Associations of health literacy with dialysis adherence and health resource utilization in patients receiving maintenance hemodialysis.

    Science.gov (United States)

    Green, Jamie A; Mor, Maria K; Shields, Anne Marie; Sevick, Mary Ann; Arnold, Robert M; Palevsky, Paul M; Fine, Michael J; Weisbord, Steven D

    2013-07-01

    Although limited health literacy is common in hemodialysis patients, its effects on clinical outcomes are not well understood. Observational study. 260 maintenance hemodialysis patients enrolled in a randomized clinical trial of symptom management strategies from January 2009 through April 2011. Limited health literacy. Dialysis adherence (missed and abbreviated treatments) and health resource utilization (emergency department visits and end-stage renal disease [ESRD]-related hospitalizations). We assessed health literacy using the Rapid Estimate of Adult Literacy in Medicine (REALM) and used negative binomial regression to analyze the independent associations of limited health literacy with dialysis adherence and health resource utilization over 12-24 months. 41 of 260 (16%) patients showed limited health literacy (REALM score, ≤60). There were 1,152 missed treatments, 5,127 abbreviated treatments, 552 emergency department visits, and 463 ESRD-related hospitalizations. Limited health literacy was associated independently with an increased incidence of missed dialysis treatments (missed, 0.6% vs 0.3%; adjusted incidence rate ratio [IRR], 2.14; 95% CI, 1.10-4.17), emergency department visits (annual visits, 1.7 vs 1.0; adjusted IRR, 1.37; 95% CI, 1.01-1.86), and hospitalizations related to ESRD (annual hospitalizations, 0.9 vs 0.5; adjusted IRR, 1.55; 95% CI, 1.03-2.34). Generalizability and potential for residual confounding. Patients receiving maintenance hemodialysis who have limited health literacy are more likely to miss dialysis treatments, use emergency care, and be hospitalized related to their kidney disease. These findings have important clinical practice and cost implications. Copyright © 2013 National Kidney Foundation, Inc. All rights reserved.

  12. Health and safety conditions of building maintenance sites in Nigeria

    African Journals Online (AJOL)

    To identify the microorganisms, bulk samples were collected on timber buildings classified as maintenance sites over the country and then identify the microorganisms available using the cultivation technique. Eight hundred and fifty nutrient and Sabouraud dextrose agar dishes were prepared. The nutrient agar dishes were ...

  13. Engine health monitoring systems: Tools for improved maintenance management in the 1980's

    Science.gov (United States)

    Kimball, J. C.

    1981-01-01

    The performance monitoring aspect of maintenance, characteristic of the engine health monitoring system are discussed. An overview of the system activities is presented and a summary of programs for improved monitoring in the 1980's are discussed.

  14. Experimental designs for autoregressive models applied to industrial maintenance

    International Nuclear Information System (INIS)

    Amo-Salas, M.; López-Fidalgo, J.; Pedregal, D.J.

    2015-01-01

    Some time series applications require data which are either expensive or technically difficult to obtain. In such cases scheduling the points in time at which the information should be collected is of paramount importance in order to optimize the resources available. In this paper time series models are studied from a new perspective, consisting in the use of Optimal Experimental Design setup to obtain the best times to take measurements, with the principal aim of saving costs or discarding useless information. The model and the covariance function are expressed in an explicit form to apply the usual techniques of Optimal Experimental Design. Optimal designs for various approaches are computed and their efficiencies are compared. The methods working in an application of industrial maintenance of a critical piece of equipment at a petrochemical plant are shown. This simple model allows explicit calculations in order to show openly the procedure to find the correlation structure, needed for computing the optimal experimental design. In this sense the techniques used in this paper to compute optimal designs may be transferred to other situations following the ideas of the paper, but taking into account the increasing difficulty of the procedure for more complex models. - Highlights: • Optimal experimental design theory is applied to AR models to reduce costs. • The first observation has an important impact on any optimal design. • Either the lack of precision or small starting observations claim for large times. • Reasonable optimal times were obtained relaxing slightly the efficiency. • Optimal designs were computed in a predictive maintenance context

  15. PSA Model Improvement Using Maintenance Rule Function Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Mi Ro [KHNP-CRI, Nuclear Safety Laboratory, Daejeon (Korea, Republic of)

    2011-10-15

    The Maintenance Rule (MR) program, in nature, is a performance-based program. Therefore, the risk information derived from the Probabilistic Safety Assessment model is introduced into the MR program during the Safety Significance determination and Performance Criteria selection processes. However, this process also facilitates the determination of the vulnerabilities in currently utilized PSA models and offers means of improving them. To find vulnerabilities in an existing PSA model, an initial review determines whether the safety-related MR functions are included in the PSA model. Because safety-related MR functions are related to accident prevention and mitigation, it is generally necessary for them to be included in the PSA model. In the process of determining the safety significance of each functions, quantitative risk importance levels are determined through a process known as PSA model basic event mapping to MR functions. During this process, it is common for some inadequate and overlooked models to be uncovered. In this paper, the PSA model and the MR program of Wolsong Unit 1 were used as references

  16. Business process modeling of industrial maintenance at TRANSPETRO: integrating oil pipeline and marine terminals activities

    Energy Technology Data Exchange (ETDEWEB)

    Arruda, Daniela Mendonca; Oliveira, Italo Luiz [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil). Diretoria de Terminais e Oleodutos; Almeida, Maria Fatima Ludovico de [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ (Brazil). Programa de Pos-Graduacao em Metrologia para Qualidade e Inovacao

    2009-07-01

    This paper describes the experience of TRANSPETRO in remodeling industrial maintenance activities focusing on: preparing for business process modeling (BPM); mapping and analyzing 'As-Is' process; designing 'To-Be' process; implementing remodeled process; improving process continuously. The conceptual model and results achieved will contribute to several areas within the company as: reliability engineering; human resources, including employees' selective processes, training and development, and certifications; standardization process encompassing standard and operational procedures adoption according to up-dating external normative references and legal requirements; health, safety and environment (HSE) performance improvement. These are some of potential benefits from BPM focusing on TRANSPETRO's industrial maintenance area in the search of operational excellence. (author)

  17. Modeling a Predictive Energy Equation Specific for Maintenance Hemodialysis.

    Science.gov (United States)

    Byham-Gray, Laura D; Parrott, J Scott; Peters, Emily N; Fogerite, Susan Gould; Hand, Rosa K; Ahrens, Sean; Marcus, Andrea Fleisch; Fiutem, Justin J

    2017-03-01

    Hypermetabolism is theorized in patients diagnosed with chronic kidney disease who are receiving maintenance hemodialysis (MHD). We aimed to distinguish key disease-specific determinants of resting energy expenditure to create a predictive energy equation that more precisely establishes energy needs with the intent of preventing protein-energy wasting. For this 3-year multisite cross-sectional study (N = 116), eligible participants were diagnosed with chronic kidney disease and were receiving MHD for at least 3 months. Predictors for the model included weight, sex, age, C-reactive protein (CRP), glycosylated hemoglobin, and serum creatinine. The outcome variable was measured resting energy expenditure (mREE). Regression modeling was used to generate predictive formulas and Bland-Altman analyses to evaluate accuracy. The majority were male (60.3%), black (81.0%), and non-Hispanic (76.7%), and 23% were ≥65 years old. After screening for multicollinearity, the best predictive model of mREE ( R 2 = 0.67) included weight, age, sex, and CRP. Two alternative models with acceptable predictability ( R 2 = 0.66) were derived with glycosylated hemoglobin or serum creatinine. Based on Bland-Altman analyses, the maintenance hemodialysis equation that included CRP had the best precision, with the highest proportion of participants' predicted energy expenditure classified as accurate (61.2%) and with the lowest number of individuals with underestimation or overestimation. This study confirms disease-specific factors as key determinants of mREE in patients on MHD and provides a preliminary predictive energy equation. Further prospective research is necessary to test the reliability and validity of this equation across diverse populations of patients who are receiving MHD.

  18. 75 FR 62684 - Health Insurance Reform; Announcement of Maintenance Changes to Electronic Data Transaction...

    Science.gov (United States)

    2010-10-13

    ... 0938-AM50 Health Insurance Reform; Announcement of Maintenance Changes to Electronic Data Transaction Standards Adopted Under the Health Insurance Portability and Accountability Act of 1996 AGENCY: Office of... of the Health Insurance Portability and Accountability Act of 1996 standards made by the Designated...

  19. Resilience associated with mental health problems among methadone maintenance treatment patients in Guangzhou, China.

    Science.gov (United States)

    Jiao, Mingxu; Gu, Jing; Xu, Huifang; Hao, Chun; Lau, Joseph T F; Mo, Phoenix; Liu, Di; Zhao, Yuteng; Zhang, Xiao; Babbitt, Andrew; Hao, Yuantao

    2017-05-01

    A considerable proportion of methadone maintenance treatment (MMT) clients have experienced mental health problems (e.g., depression and anxiety), and poor mental health status is associated with HIV-related risk behaviors and treatment drop-out. Resilience is known to be a protective factor for mental health problems but is not studied among MMT clients in China. This study aimed to explore the relationship between resilience and mental health problems (depression, anxiety and stress) among clients of community-based MMT clinics in China. A total of 208 MMT clients completed the face-to-face interview conducted at 4 of 11 MMT clinics in Guangzhou. The Chinese short version of Depression Anxiety Stress Scale (DASS-21) was used to assess the presence of depressive, anxiety and stress symptoms, and the Connor-Davidson Resilience Scale (CD-RISC) was used to measure resilience. Logistic regression models were fit in data analyses. Of all participants, 12.8%, 19.5% and 8.3% had depression, anxiety and stress, respectively. The mean resilience score was 57.6 (SD = 15.9). In the univariate analyses, resilience was negatively associated with two studied mental health problems (depression and anxiety, OR u  = 0.96 and 0.96, p mental health problems of MMT users should consider resilience as an important part in the designing of such interventions.

  20. Optimisation of distributed maintenance: Modelling and application to the multi-factory production

    Energy Technology Data Exchange (ETDEWEB)

    Simeu-Abazi, Zineb, E-mail: Zineb.Simeu-Abazi@g-scop.inpg.fr [Laboratory G-SCOP, 46 Avenue Felix Viallet, 38031 Grenoble Cedex 1 (France); Ahmad, Alali Alhouaij [Laboratory G-SCOP, 46 Avenue Felix Viallet, 38031 Grenoble Cedex 1 (France)

    2011-11-15

    This paper concerns the modelling and the cost evaluation of maintenance activities in a distributed context. In this work we study the particular case where the maintenance activities are executed by two workshops: a central maintenance workshop (CMW) and a mobile maintenance workshop (MMW). The CMW concerns the repairing process for the corrective maintenance and the MMW executes all preventive maintenance in several factories according to a defined scheduling. The aim is to take into account the resources (spare parts in the MMW) and maintenance actions for a given operating budget. A modular approach for modelling a multi-site structure is proposed to achieve the aim of improving the availability of facilities on production sites while minimising the cost of maintenance.

  1. Health Maintenance System (HMS) Hardware Research, Design, and Collaboration

    Science.gov (United States)

    Gonzalez, Stefanie M.

    2010-01-01

    The Space Life Sciences division (SLSD) concentrates on optimizing a crew member's health. Developments are translated into innovative engineering solutions, research growth, and community awareness. This internship incorporates all those areas by targeting various projects. The main project focuses on integrating clinical and biomedical engineering principles to design, develop, and test new medical kits scheduled for launch in the Spring of 2011. Additionally, items will be tagged with Radio Frequency Interference Devices (RFID) to keep track of the inventory. The tags will then be tested to optimize Radio Frequency feed and feed placement. Research growth will occur with ground based experiments designed to measure calcium encrusted deposits in the International Space Station (ISS). The tests will assess the urine calcium levels with Portable Clinical Blood Analyzer (PCBA) technology. If effective then a model for urine calcium will be developed and expanded to microgravity environments. To support collaboration amongst the subdivisions of SLSD the architecture of the Crew Healthcare Systems (CHeCS) SharePoint site has been redesigned for maximum efficiency. Community collaboration has also been established with the University of Southern California, Dept. of Aeronautical Engineering and the Food and Drug Administration (FDA). Hardware disbursements will transpire within these communities to support planetary surface exploration and to serve as an educational tool demonstrating how ground based medicine influenced the technological development of space hardware.

  2. Job analysis of maintenance-mechanic position for the nuclear power plant maintenance personnel reliability model

    International Nuclear Information System (INIS)

    Siegel, A.I.; Bartter, W.D.; Kopstein, F.F.

    1982-06-01

    The task list method of job survey was used. In collaboration with BWR and PWR personnel, a list of 107 tasks performed by maintenance mechanics was developed, grouped into: remove and install, test and repair, inspect and perform preventive maintenance, miscellaneous, communication, and report preparation. For each listed task, the questionnaire form inquired into: frequency of performance, task completion time, safety consequences of improper performance, and the amount of training required to perform the task proficiently. Scaled information was requested about seven abilities: (1) visual speed, accuracy, and recognition; (2) gross motor coordination; (3) fine manual dexterity; (4) strength and stamina; (5) cognition; (6) memory; and (7) problem solving required for function completion. Survey forms were distributed to 27 nuclear power plants. Thirty-one maintenance mechanics representing 17 plants returned the completed forms. Frequency of performing tasks was bimodally distributed: (1) between once a year and once every six months, and (2) about once a week. More than half of the tasks have potential risk consequences if improperly performed. The five tasks with the greatest risk implications in the case of inadequate performance were: (1) remove and install reactor and dry-well heads, (2) test and repair reactor system components, (3) remove and install pressurizer mechanical relief valves, (4) test and repair pressurizer relief valves, (5) remove and install core spray pumps, seals, and valves. Hierarchically, the public risk associated with the various functions was: (1) remove and install, (2) test and repair, (3) preventive maintenance, (4) miscellaneous tasks, (5) communication, and (6) report preparation

  3. On the impact of optimisation models in maintenance decision making: the state of the art

    International Nuclear Information System (INIS)

    Dekker, Rommert; Scarf, Philip A.

    1998-01-01

    In this paper we discuss the state of the art in applications of maintenance optimisation models. After giving a short introduction to the area, we consider several ways in which models may be used to optimise maintenance, such as case studies, operational and strategic decision support systems, and give examples of each of them. Next we discuss several areas where the models have been applied successfully. These include civil structure and aeroplane maintenance. From a comparative point of view, we discuss future prospects

  4. A bivariate process model for maintenance and inspection planning

    NARCIS (Netherlands)

    Newby, M.J.; Barker, C.T.

    2006-01-01

    The paper describes decision making about monitoring and maintenance of systems described by a general stochastic process. The system is monitored and preventive and corrective maintenance actions are carried out in response to the observed system state. The decision process is simplified by using

  5. Predictive maintenance of maritime systems : models and challenges

    NARCIS (Netherlands)

    Tinga, T.; Tiddens, W.W.; Amoiralis, F.; Politis, M.; Cepin, Marko; Bris, Radim

    2017-01-01

    To reduce maintenance and logistic costs and increase the asset availability, a predictive maintenance concept for maritime systems is developed. In the present paper, the physics-of-failure based prognostic methods will be introduced, but also other issues related to the development and application

  6. Performance deterioration modeling and optimal preventive maintenance strategy under scheduled servicing subject to mission time

    Directory of Open Access Journals (Sweden)

    Li Dawei

    2014-08-01

    Full Text Available Servicing is applied periodically in practice with the aim of restoring the system state and prolonging the lifetime. It is generally seen as an imperfect maintenance action which has a chief influence on the maintenance strategy. In order to model the maintenance effect of servicing, this study analyzes the deterioration characteristics of system under scheduled servicing. And then the deterioration model is established from the failure mechanism by compound Poisson process. On the basis of the system damage value and failure mechanism, the failure rate refresh factor is proposed to describe the maintenance effect of servicing. A maintenance strategy is developed which combines the benefits of scheduled servicing and preventive maintenance. Then the optimization model is given to determine the optimal servicing period and preventive maintenance time, with an objective to minimize the system expected life-cycle cost per unit time and a constraint on system survival probability for the duration of mission time. Subject to mission time, it can control the ability of accomplishing the mission at any time so as to ensure the high dependability. An example of water pump rotor relating to scheduled servicing is introduced to illustrate the failure rate refresh factor and the proposed maintenance strategy. Compared with traditional methods, the numerical results show that the failure rate refresh factor can describe the maintenance effect of servicing more intuitively and objectively. It also demonstrates that this maintenance strategy can prolong the lifetime, reduce the total lifetime maintenance cost and guarantee the dependability of system.

  7. A novel approach for modelling complex maintenance systems using discrete event simulation

    International Nuclear Information System (INIS)

    Alrabghi, Abdullah; Tiwari, Ashutosh

    2016-01-01

    Existing approaches for modelling maintenance rely on oversimplified assumptions which prevent them from reflecting the complexity found in industrial systems. In this paper, we propose a novel approach that enables the modelling of non-identical multi-unit systems without restrictive assumptions on the number of units or their maintenance characteristics. Modelling complex interactions between maintenance strategies and their effects on assets in the system is achieved by accessing event queues in Discrete Event Simulation (DES). The approach utilises the wide success DES has achieved in manufacturing by allowing integration with models that are closely related to maintenance such as production and spare parts systems. Additional advantages of using DES include rapid modelling and visual interactive simulation. The proposed approach is demonstrated in a simulation based optimisation study of a published case. The current research is one of the first to optimise maintenance strategies simultaneously with their parameters while considering production dynamics and spare parts management. The findings of this research provide insights for non-conflicting objectives in maintenance systems. In addition, the proposed approach can be used to facilitate the simulation and optimisation of industrial maintenance systems. - Highlights: • This research is one of the first to optimise maintenance strategies simultaneously. • New insights for non-conflicting objectives in maintenance systems. • The approach can be used to optimise industrial maintenance systems.

  8. Vehicle Remote Health Monitoring and Prognostic Maintenance System

    Directory of Open Access Journals (Sweden)

    Uferah Shafi

    2018-01-01

    Full Text Available In many industries inclusive of automotive vehicle industry, predictive maintenance has become more important. It is hard to diagnose failure in advance in the vehicle industry because of the limited availability of sensors and some of the designing exertions. However with the great development in automotive industry, it looks feasible today to analyze sensor’s data along with machine learning techniques for failure prediction. In this article, an approach is presented for fault prediction of four main subsystems of vehicle, fuel system, ignition system, exhaust system, and cooling system. Sensor is collected when vehicle is on the move, both in faulty condition (when any failure in specific system has occurred and in normal condition. The data is transmitted to the server which analyzes the data. Interesting patterns are learned using four classifiers, Decision Tree, Support Vector Machine, K Nearest Neighbor, and Random Forest. These patterns are later used to detect future failures in other vehicles which show the similar behavior. The approach is produced with the end goal of expanding vehicle up-time and was demonstrated on 70 vehicles of Toyota Corolla type. Accuracy comparison of all classifiers is performed on the basis of Receiver Operating Characteristics (ROC curves.

  9. Model-based fault diagnosis framework for effective predictive maintenance / B.B. Akindele

    OpenAIRE

    Akindele, Babatunde Babajide

    2010-01-01

    Predictive maintenance is a proactive maintenance strategy that is aimed at preventing the unexpected failure of equipment through condition monitoring of the health and performance of the equipment. Incessant equipment outage resulting in low availability of production facilities is a major issue in the Nigerian manufacturing environment. Improving equipment availability in Nigeria industry through institution of a full featured predictive maintenance has been suggested by many authors. T...

  10. A "small-changes" workplace weight loss and maintenance program: examination of weight and health outcomes.

    Science.gov (United States)

    Zinn, Caryn; Schofield, Grant M; Hopkins, Will G

    2012-10-01

    To compare the effect of "small-changes" and "usual care" workplace interventions on weight loss and to investigate the effect of small changes with or without maintenance on weight and health outcomes. Overweight/obese employees at two New Zealand worksites received a 12-month usual-care intervention (n = 53), followed by a 12-month small-changes intervention (n = 102). Small changes comprised a 12-week component, followed by 9 months of maintenance, implemented at only one worksite. Magnitudes of effects were assessed via a threshold of -5% (weight loss) and standardization (health outcomes). Small changes showed beneficial weight loss relative to usual care in both worksites. For small-changes interventions, worksites reduced weight (12 weeks) and maintained lost weight (12 months). One in every three participants lost 5% or more weight. Some improvements in health outcomes were shown. Regardless of maintenance, the small-changes intervention was successful in sustaining weight loss.

  11. The Long-term Outcomes of Sibutramine Effectiveness on Weight (LOSE Weight) study: evaluating the role of drug therapy within a weight management program in a group-model health maintenance organization.

    Science.gov (United States)

    Porter, Julie A; Raebel, Marsha A; Conner, Douglas A; Lanty, Frances A; Vogel, Erin A; Gay, Elizabeth C; Merenich, John A

    2004-06-01

    To assess the benefit of sibutramine hydrochloride monohydrate within a weight management program. Prospective randomized controlled trial in a health maintenance organization. Obese patients (n = 588) starting a weight management program were enrolled. Patients were randomly assigned to participate in the program alone or to participate in the program and receive sibutramine for 12 months. Outcome measures were change in weight, body mass index (BMI), percentage body fat, serum lipids, serum glucose, and blood pressure. At baseline, there was a younger age and higher weight, BMI, and waist circumference in the drug group. There was more degenerative joint disease in the nondrug group. The mean weight loss at 6 months was 6.8 kg (95% confidence interval [CI], -7.4 to -6.1 kg) in the drug group vs 3.1 kg (95% CI, -3.8 to -2.4 kg) (P managed care setting, the effectiveness and safety of sibutramine were similar to those observed in randomized, double-blind clinical efficacy trials.

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

    OpenAIRE

    M. A., Burhanuddin; Halawani, Sami M.; Ahmad, A. R.

    2011-01-01

    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 c...

  13. 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.

  14. Evaluation and comparison of alternative fleet-level selective maintenance models

    International Nuclear Information System (INIS)

    Schneider, Kellie; Richard Cassady, C.

    2015-01-01

    Fleet-level selective maintenance refers to the process of identifying the subset of maintenance actions to perform on a fleet of repairable systems when the maintenance resources allocated to the fleet are insufficient for performing all desirable maintenance actions. The original fleet-level selective maintenance model is designed to maximize the probability that all missions in a future set are completed successfully. We extend this model in several ways. First, we consider a cost-based optimization model and show that a special case of this model maximizes the expected value of the number of successful missions in the future set. We also consider the situation in which one or more of the future missions may be canceled. These models and the original fleet-level selective maintenance optimization models are nonlinear. Therefore, we also consider an alternative model in which the objective function can be linearized. We show that the alternative model is a good approximation to the other models. - Highlights: • Investigate nonlinear fleet-level selective maintenance optimization models. • A cost based model is used to maximize the expected number of successful missions. • Another model is allowed to cancel missions if reliability is sufficiently low. • An alternative model has an objective function that can be linearized. • We show that the alternative model is a good approximation to the other models

  15. A preventive maintenance model for leased equipment subject to internal degradation and external shock damage

    International Nuclear Information System (INIS)

    Zhou, Xiaojun; Wu, Changjie; Li, Yanting; Xi, Lifeng

    2016-01-01

    A periodic preventive maintenance modeling method is proposed for leased equipment with continuous internal degradation and stochastic external shock damage considered simultaneously, which can facilitate the equipment lessor to optimize the maintenance schedule for the same kind of equipment rented by different lessees. A novel interactive mechanism between the continuous internal degradation and the stochastic external shock damage is established on the hazard rate of the equipment with integrating the imperfect effect of maintenance. Two improvement factors are defined for the modeling of imperfect maintenance. The number of failures resulting from internal degradation and from external shocks are both mathematically deduced based on this interactive mechanism. The optimal preventive maintenance scheme is obtained by minimizing the cumulative maintenance cost throughout the lease period. Numerical example shows that the proposed preventive maintenance model not only can reflect the reliability status of the equipment but also can clearly distinguish between the impact from internal degradation and that from external shocks. - Highlights: • We propose an imperfect periodic preventive maintenance model for leased equipment. • It can distinguish between the impact from internal degradation and that from external shocks. • An internal–external interactive mechanism is proposed. • Two improvement factors are introduced into the modeling of imperfect maintenance. • The model is helpful for the PM scheduling of the same equipment rented by different lessees.

  16. New Models for Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Petersen, Kristian R.

    component that was causing a large amount of downtime were identified. Further analysis with the Reliability-Centred Maintenance concept helped determine the most appropriate maintenance strategy. In the final perspective, long-term strategic decisions were the focus. Asset Management and especially Asset...... Life-Cycle Management were studied using a case study. The case study analysis was used to generate strategies to help managers perform maintenance more proactively and to prepare the management of the offshore wind farm turbines for the future. Existing literature on Asset Life-Cycle Management has......Operations and maintenance (O&M) processes are important for keeping offshore wind turbines in operation. Costs related to such activities constitute approximately 30% of the lifetime cost of an offshore wind farm project. Currently, the offshore wind energy industry has shown a rapid increase...

  17. Fleet equipment performance measurement preventive maintenance model : final report.

    Science.gov (United States)

    2014-04-01

    The concept of preventive maintenance is very important in the effective management and deployment of : vehicle fleets. The Texas Department of Transportation (TxDOT) operates a large fleet of on-road and offroad : equipment. Newer engines and vehicl...

  18. Maintenance and operations cost model for DSN subsystems

    Science.gov (United States)

    Burt, R. W.; Lesh, J. R.

    1977-01-01

    A procedure is described which partitions the recurring costs of the Deep Space Network (DSN) over the individual DSN subsystems. The procedure results in a table showing the maintenance, operations, sustaining engineering and supportive costs for each subsystems.

  19. Critical factors in recruiting health maintenance organization physicians.

    Science.gov (United States)

    Fisher, N B; Smith, H L; Pasternak, D P

    1993-01-01

    What factors facilitate successful physician recruiting by health care organizations? Answers surfaced in a study of physician recruiting by a large HMO in the Southwest. Professional networking and word-of-mouth advertising appear to be the prominent means by which physicians learn of attractive staff positions. Successful recruiting also depends on a practice setting that fosters quality care, emphasis on patient care delivery, and collegial interaction.

  20. Calcium intake in health maintenance – a systematic review

    Directory of Open Access Journals (Sweden)

    Kirsti Uusi-Rasi

    2013-05-01

    Full Text Available Background: Calcium (Ca is an essential nutrient for the human body. Despite lively research, there is uncertainty about Ca requirements in terms of desirable health outcomes including an upper intake level above which the potential for harm increases. Objectives: The aim was to conduct a review to update requirements and desirable or harmful health effects of Ca on the current scientific evidence. Methods: We searched Medline and Swemed from January 2000 to December 2011 and included all systematic reviews that reported Ca supplementation or usual Ca intake on health outcomes. Meta-analyses, randomized clinical trials and cohort studies were included in the second search between May 2009 and March 2011 and an additional search covering studies till the end of 2011. This review concentrated on studies reporting independent effects of Ca, although a few recent trials report sole effects of Ca on health outcomes, most trials use Ca in combination with vitamin D vs. placebo. Results: In total, we reviewed 38 studies addressing the effects of Ca on bone, pregnancy-related outcomes, cancers, cardiovascular outcomes, obesity, and mortality. There was a lot of heterogeneity in the study protocols, which made it difficult to draw any strong conclusions. According to the literature, high Ca intake seems to have a small positive effect on bone mineral content (BMC or bone mineral density (BMD in children and postmenopausal women. We did not find any consistent evidence on the effects of Ca on bone health in premenopausal women or men. Also, the evidence that Ca supplementation reduces fracture incidence is scarce and inconsistent. Maternal diet may influence the peak bone mass of offspring but more studies are required. There was no overall effect of Ca intake on cancers. Ca was associated with a decreased risk of breast cancer and a slightly increased risk of prostate cancer in two of the three studies. No associations were found with other cancers. We

  1. Adolescent health care maintenance in a teen-friendly clinic.

    Science.gov (United States)

    Chaisson, Nicole; Shore, William B

    2014-09-01

    Adolescence is marked by complex physical, cognitive, social, and emotional development, which can be stressful for families and adolescents. Before the onset of puberty, providers should clearly lay the groundwork for clinical care and office visits during the adolescent years. This article addresses the guidelines and current legal standards for confidentiality in adolescent care, the most frequently used psychosocial screening tools, and current recommendations for preventive health services and immunizations. Through the creation of teen-friendly clinics, primary care providers are well positioned to offer guidance and support to teens and their parents during this time of transition and growth. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. 29 CFR 825.211 - Maintenance of benefits under multi-employer health plans.

    Science.gov (United States)

    2010-07-01

    ..., DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical Leave Act § 825.211 Maintenance of benefits under multi-employer health plans. (a) A... that the employee would have been laid off and the employment relationship terminated; or, (3) The...

  3. An integrated production, inventory and preventive maintenance model for a multi-product production system

    International Nuclear Information System (INIS)

    Liu, Xuejuan; Wang, Wenbin; Peng, Rui

    2015-01-01

    This paper considers a production system that can produce multiple products alternately. Products go through the system in a sequence and a complete run of all products forms a production cycle. An integrated production, inventory and preventive maintenance model is constructed, which is characterized by the delay-time concept. Two different situations are studied based on whether the unqualified products and downtime caused by the failures of the system, set-up and preventive maintenance can be ignored or not. Three cases are considered for each situation, depending on the position of the preventive maintenance epochs: the first case, where preventive maintenance is carried out at the end of each production cycle; the second case, where preventive maintenance is carried out at each set-up time of the products; and the third case, where preventive maintenance is carried out at some set-up times only, since it may not always be optimal to carry out preventive maintenance at the end of the production cycle or at each set-up time. The modeling objectives are to find the optimal number of production cycles per year and the optimal position of preventive maintenance that will maximize the expected profit per unit time. Numerical examples, using real data, are presented to illustrate the model. - Highlights: • We propose an integrated economic production quantity and preventive maintenance model. • The situation that multiple products are produced on the same system alternately is studied. • Two situations are studied based on whether the downtime and the product quality can be ignored or not. • We use enumeration method and analytical method to select the optimal preventive maintenance policy, respectively. • We use the delay-time concept to model the preventive maintenance policy

  4. On reliability and maintenance modelling of ageing equipment in electric power systems

    International Nuclear Information System (INIS)

    Lindquist, Tommie

    2008-04-01

    Maintenance optimisation is essential to achieve cost-efficiency, availability and reliability of supply in electric power systems. The process of maintenance optimisation requires information about the costs of preventive and corrective maintenance, as well as the costs of failures borne by both electricity suppliers and customers. To calculate expected costs, information is needed about equipment reliability characteristics and the way in which maintenance affects equipment reliability. The aim of this Ph.D. work has been to develop equipment reliability models taking the effect of maintenance into account. The research has focussed on the interrelated areas of condition estimation, reliability modelling and maintenance modelling, which have been investigated in a number of case studies. In the area of condition estimation two methods to quantitatively estimate the condition of disconnector contacts have been developed, which utilise results from infrared thermography inspections and contact resistance measurements. The accuracy of these methods were investigated in two case studies. Reliability models have been developed and implemented for SF6 circuit-breakers, disconnector contacts and XLPE cables in three separate case studies. These models were formulated using both empirical and physical modelling approaches. To improve confidence in such models a Bayesian statistical method incorporating information from the equipment design process was also developed. This method was illustrated in a case study of SF6 circuit-breaker operating rods. Methods for quantifying the effect of maintenance on equipment condition and reliability have been investigated in case studies on disconnector contacts and SF6 circuit-breakers. The input required by these methods are condition measurements and historical failure and maintenance data, respectively. This research has demonstrated that the effect of maintenance on power system equipment may be quantified using available data

  5. Prediction of Combine Economic Life Based on Repair and Maintenance Costs Model

    Directory of Open Access Journals (Sweden)

    A Rohani

    2014-09-01

    Full Text Available Farm machinery managers often need to make complex economic decisions on machinery replacement. Repair and maintenance costs can have significant impacts on this economic decision. The farm manager must be able to predict farm machinery repair and maintenance costs. This study aimed to identify a regression model that can adequately represent the repair and maintenance costs in terms of machine age in cumulative hours of use. The regression model has the ability to predict the repair and maintenance costs for longer time periods. Therefore, it can be used for the estimation of the economic life. The study was conducted using field data collected from 11 John-Deer 955 combine harvesters used in several western provinces of Iran. It was found that power model has a better performance for the prediction of combine repair and maintenance costs. The results showed that the optimum replacement age of John-Deer 955 combine was 54300 cumulative hours.

  6. Predicting older adults' maintenance in exercise participation using an integrated social psychological model

    NARCIS (Netherlands)

    Stiggelbout, M.; Hopman-Rock, M.; Crone, M.; Lechner, L.; Mechelen, W. van

    2006-01-01

    Little is known about the predictors of maintenance in organized exercise programmes. The aim of this study was to investigate the behavioral predictors of maintenance of exercise participation in older adults, using an integrated social psychological model. To this end, we carried out a prospective

  7. 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.

  8. 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

  9. What Predicts Exercise Maintenance and Well-Being? Examining The Influence of Health-Related Psychographic Factors and Social Media Communication.

    Science.gov (United States)

    Zhou, Xin; Krishnan, Archana

    2018-01-26

    Habitual exercising is an important precursor to both physical and psychological well-being. There is, thus, a strong interest in identifying key factors that can best motivate individuals to sustain regular exercise regimen. In addition to the importance of psychographic factors, social media use may act as external motivator by allowing users to interact and communicate about exercise. In this study, we examined the influence of health consciousness, health-oriented beliefs, intrinsic motivation, as willingness to communicate about health on social media, social media activity on exercise, and online social support on exercise maintenance and well-being on a sample of 532 American adults. Employing structural equation modeling, we found that health-oriented beliefs mediated the effect of health consciousness on intrinsic motivation which in turn was a significant predictor of exercise maintenance. Exercise maintenance significantly predicted both physical and psychological well-being. Extrinsic motivators, as measured by willingness to communicate about health on social media, social media activity on exercise, and online social support did not however significantly influence exercise maintenance. These findings have implications for the design and implementation of exercise-promoting interventions by identifying underlying factors that influence exercise maintenance.

  10. Operation and maintenance of thermal power stations best practices and health monitoring

    CERN Document Server

    Chanda, Pradip

    2016-01-01

    This book illustrates operation and maintenance practices/guidelines for economic generation and managing health of a thermal power generator beyond its regulatory life. The book provides knowledge for professionals managing power station operations, through its unique approach to chemical analysis of water, steam, oil etc. to identify malfunctioning/defects in equipment/systems much before the physical manifestation of the problem. The book also contains a detailed procedure for conducting performance evaluation tests on different equipment, and for analyzing test results for predicting maintenance requirements, which has lent a new dimension to power systems operation and maintenance practices. A number of real life case studies also enrich the book. This book will prove particularly useful to power systems operations professionals in the developing economies, and also to researchers and students involved in studying power systems operations and control. .

  11. Laboratory equipment maintenance: a critical bottleneck for strengthening health systems in sub-Saharan Africa?

    Science.gov (United States)

    Fonjungo, Peter N; Kebede, Yenew; Messele, Tsehaynesh; Ayana, Gonfa; Tibesso, Gudeta; Abebe, Almaz; Nkengasong, John N; Kenyon, Thomas

    2012-02-01

    Properly functioning laboratory equipment is a critical component for strengthening health systems in developing countries. The laboratory can be an entry point to improve population health and care of individuals for targeted diseases - prevention, care, and treatment of TB, HIV/AIDS, and malaria, plus maternal and neonatal health - as well as those lacking specific attention and funding. We review the benefits and persistent challenges associated with sustaining laboratory equipment maintenance. We propose equipment management policies as well as a comprehensive equipment maintenance strategy that would involve equipment manufacturers and strengthen local capacity through pre-service training of biomedical engineers. Strong country leadership and commitment are needed to assure development and sustained implementation of policies and strategies for standardization of equipment, and regulation of its procurement, donation, disposal, and replacement.

  12. Building and integrating reliability models in a Reliability-Centered-Maintenance approach

    International Nuclear Information System (INIS)

    Verite, B.; Villain, B.; Venturini, V.; Hugonnard, S.; Bryla, P.

    1998-03-01

    Electricite de France (EDF) has recently developed its OMF-Structures method, designed to optimize preventive maintenance of passive structures such as pipes and support, based on risk. In particular, reliability performances of components need to be determined; it is a two-step process, consisting of a qualitative sort followed by a quantitative evaluation, involving two types of models. Initially, degradation models are widely used to exclude some components from the field of preventive maintenance. The reliability of the remaining components is then evaluated by means of quantitative reliability models. The results are then included in a risk indicator that is used to directly optimize preventive maintenance tasks. (author)

  13. Where does “whichever occurs first” hold for preventive maintenance modelings?

    International Nuclear Information System (INIS)

    Zhao, Xufeng; Liu, Hu-Chen; Nakagawa, Toshio

    2015-01-01

    The purpose of this paper is to observe where the classical assumption “whichever occurs first” holds for preventive maintenance (PM) modelings. We firstly take up a bivariate maintenance policy where “whichever occurs first” and the newly proposed “whichever occurs last” are respectively used. Modification of PM performance is introduced into modelings to avoid interruptions of job executions, that is, PMs are done only at the end of working cycles. From the points of performability and maintenance cost, we secondly compare the optimized “first” and “last” policies in detail and find two critical points of comparisons analytically. Further, by comparing the “first” and “last” policies with the standard maintenance, modified PM costs are obtained to observe whether it is easy to save PM cost for “whichever occurs first”. For a trivariate maintenance policy, we thirdly propose an entirely new assumption “whichever occurs middle” and give another one model that considers both assumptions of “first” and “last”. We analyze maintenance probabilities for each model and then obtain directly their expected maintenance cost rates for further studies. - Highlights: • A bivariate maintenance policy based on “whichever occurs first” is improved. • Two comparisons of “whichever occurs first and last” are made. • Modified maintenance costs are obtained to observe which policy could save more costs. • New assumption “whichever occurs middle” for the trivariate maintenances is proposed. • One policy is modeled by considering both assumptions of “first” and “last”

  14. 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.

  15. Design of the system of maintenance operations occupational safety and health database application of nuclear power station

    International Nuclear Information System (INIS)

    Wang Xuehong; Li Xiangyang; Ye Yongjun

    2011-01-01

    Based on the KKS code of building equipment in nuclear power station, this paper introduces the method of establishing the system of maintenance operation occupational safety and health database application. Through the application system of maintenance occupational safety and health database, it can summarize systematically all kinds of maintenance operation dangerous factor of nuclear power station, and make a convenience for staff to learn the maintenance operation dangerous factors and the prevention measures, so that it can achieve the management concept of 'precaution crucial, continuous improvement' that advocated by OSHMS. (authors)

  16. A theoretical reassessment of microbial maintenance and implications for microbial ecology modeling.

    Science.gov (United States)

    Wang, Gangsheng; Post, Wilfred M

    2012-09-01

    We attempted to reconcile three microbial maintenance models (Herbert, Pirt, and Compromise) through a theoretical reassessment. We provided a rigorous proof that the true growth yield coefficient (Y(G)) is the ratio of the specific maintenance rate (a in Herbert) to the maintenance coefficient (m in Pirt). Other findings from this study include: (1) the Compromise model is identical to the Herbert for computing microbial growth and substrate consumption, but it expresses the dependence of maintenance on both microbial biomass and substrate; (2) the maximum specific growth rate in the Herbert (μ(max,H)) is higher than those in the other two models (μ(max,P) and μ(max,C)), and the difference is the physiological maintenance factor (m(q) = a); and (3) the overall maintenance coefficient (m(T)) is more sensitive to m(q) than to the specific growth rate (μ(G)) and Y(G). Our critical reassessment of microbial maintenance provides a new approach for quantifying some important components in soil microbial ecology models. © This article is a US government work and is in the public domain in the USA.

  17. Building a maintenance policy through a multi-criterion decision-making model

    Science.gov (United States)

    Faghihinia, Elahe; Mollaverdi, Naser

    2012-08-01

    A major competitive advantage of production and service systems is establishing a proper maintenance policy. Therefore, maintenance managers should make maintenance decisions that best fit their systems. Multi-criterion decision-making methods can take into account a number of aspects associated with the competitiveness factors of a system. This paper presents a multi-criterion decision-aided maintenance model with three criteria that have more influence on decision making: reliability, maintenance cost, and maintenance downtime. The Bayesian approach has been applied to confront maintenance failure data shortage. Therefore, the model seeks to make the best compromise between these three criteria and establish replacement intervals using Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE II), integrating the Bayesian approach with regard to the preference of the decision maker to the problem. Finally, using a numerical application, the model has been illustrated, and for a visual realization and an illustrative sensitivity analysis, PROMETHEE GAIA (the visual interactive module) has been used. Use of PROMETHEE II and PROMETHEE GAIA has been made with Decision Lab software. A sensitivity analysis has been made to verify the robustness of certain parameters of the model.

  18. The state-of-the-art Model M-2 Maintenance System

    International Nuclear Information System (INIS)

    Herndon, J.N.; Martin, H.L.; Satterlee, P.E. Jr.; Jelatis, D.G.; Jennrich, C.E.

    1984-01-01

    The Model M-2 Maintenance System is part of an ongoing program within the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) to improve remote manipulation technology for future nuclear fuel reprocessing and other remote applications. Techniques, equipment, and guidelines which can improve the efficiency of remote maintenance are being developed. The Model M-2 Maintenance System, installed in the Integrated Equipment Test (IET) Facility at ORNL, provides a complete, integrated remote maintenance system for the demonstration and development of remote maintenance techniques. The system comprises a pair of force-reflecting servomanipulator arms, television viewing, lighting, and auxiliary lifting capabilities, thereby allowing manlike maintenance operations to be executed remotely within the remote cell mockup area in the IET. The Model M-2 Maintenance System incorporates an upgraded version of the proven Central Research Laboratories' Model M servomanipulator. Included are state-of-the-art brushless dc servomotors for improved performance, remotely removable wrist assemblies, geared azimuth drive, and a distributed microprocessor-based digital control system

  19. 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

  20. Developing a Predictive Model for Unscheduled Maintenance Requirements on United States Air Force Installations

    National Research Council Canada - National Science Library

    Kovich, Matthew D; Norton, J. D

    2008-01-01

    .... This paper develops one such method by using linear regression and time series analysis to develop a predictive model to forecast future year man-hour and funding requirements for unscheduled maintenance...

  1. Stress-reducing preventive maintenance model for a unit under stressful environment

    International Nuclear Information System (INIS)

    Park, J.H.; Chang, Woojin; Lie, C.H.

    2012-01-01

    We develop a preventive maintenance (PM) model for a unit operated under stressful environment. The PM model in this paper consists of a failure rate model and two cost models to determine the optimal PM scheduling which minimizes a cost rate. The assumption for the proposed model is that stressful environment accelerates the failure of the unit and periodic maintenances reduce stress from outside. The failure rate model handles the maintenance effect of PM using improvement and stress factors. The cost models are categorized into two failure recognition cases: immediate failure recognition and periodic failure detection. The optimal PM scheduling is obtained by considering the trade-off between the related cost and the lifetime of a unit in our model setting. The practical usage of our proposed model is tested through a numerical example.

  2. Maintenance model for the No. 2 1300 MW unit at Philippsburg nuclear power station

    International Nuclear Information System (INIS)

    Gamer, M.; Jaeger, E.; Woehrle, G.

    1983-01-01

    In 1979 a maintenance model to the scale 1:1 was constructed for the second extension of Philippsburg Nuclear Power Station. The objective of this model, the building of which was completed at the end of 1982, the physical arrangement of the overall maintenance regime and the practice-oriented application of the ergonomics, in particular in relation to the optimization of the man-machine interface, are described. (orig.) [de

  3. Formalisation of a new prognosis model for supporting proactive maintenance implementation on industrial system

    International Nuclear Information System (INIS)

    Muller, Alexandre; Suhner, Marie-Christine; 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 maintenance concept has undergone several major developments that have led to proactive considerations mainly based on a prognosis process, which normally allows selection of the best maintenance action to be carried out. This paper proposes the deployment and experimentation of a prognosis process within an e-maintenance architecture. The deployment follows a methodology based on the combination of both a probabilistic approach for modelling the degradation mechanism and of an event one for dynamical degradation monitoring. The feasibility and benefits of this new prognosis process is investigated with an experiment using a manufacturing TELMA (TELe-MAintenance) platform supporting the unwinding of metal bobbins

  4. Optimal policies for cumulative damage models with maintenance last and first

    International Nuclear Information System (INIS)

    Zhao, Xufeng; Qian, Cunhua; Nakagawa, Toshio

    2013-01-01

    From the economical viewpoint of several combined PM policies in reliability theory, this paper takes up a standard cumulative damage model in which the notion of maintenance last is applied, i.e., the unit undergoes preventive maintenances before failure at a planned time T, at a damage level Z, or at a shock number N, whichever occurs last. Expected cost rates are detailedly formulated, and optimal problems of two alternative policies which combine time-based with condition-based preventive maintenances are discussed, i.e., optimal T L ⁎ for N, Z L ⁎ for T, and N L ⁎ for T are rigorously obtained. Comparison methods between such maintenance last and conventional maintenance first are explored. It is determined theoretically and numerically which policy should be adopted, according to the different methods in different cases when the time-based or the condition-based PM policy is optimized.

  5. A framework to practical predictive maintenance modeling for multi-state systems

    International Nuclear Information System (INIS)

    Cher Ming Tan; Raghavan, Nagarajan

    2008-01-01

    A simple practical framework for predictive maintenance (PdM)-based scheduling of multi-state systems (MSS) is developed. The maintenance schedules are derived from a system-perspective using the failure times of the overall system as estimated from its performance degradation trends. The system analyzed in this work is a flow transmission water pipe system. The various factors influencing PdM-based scheduling are identified and their impact on the system reliability and performance are quantitatively studied. The estimated times to replacement of the MSS may also be derived from the developed model. The results of the model simulation demonstrate the significant impact of maintenance quality and the criteria for the call for maintenance (user demand) on the system reliability and mean performance characteristics. A slight improvement in maintenance quality is found to postpone the system replacement time by manifold. The consistency in the quality of maintenance work with minimal variance is also identified as a very important factor that enhances the system's future operational and downtime event predictability. The studies also reveal that in order to reduce the frequency of maintenance actions, it is necessary to lower the minimum user demand from the system if possible, ensuring at the same time that the system still performs its intended function effectively. The model proposed can be utilized to implement a PdM program in the industry with a few modifications to suit the individual industrial systems' needs

  6. MAPPS (Maintenance Personnel Performance Simulation): a computer simulation model for human reliability analysis

    International Nuclear Information System (INIS)

    Knee, H.E.; Haas, P.M.

    1985-01-01

    A computer model has been developed, sensitivity tested, and evaluated capable of generating reliable estimates of human performance measures in the nuclear power plant (NPP) maintenance context. The model, entitled MAPPS (Maintenance Personnel Performance Simulation), is of the simulation type and is task-oriented. It addresses a number of person-machine, person-environment, and person-person variables and is capable of providing the user with a rich spectrum of important performance measures including mean time for successful task performance by a maintenance team and maintenance team probability of task success. These two measures are particularly important for input to probabilistic risk assessment (PRA) studies which were the primary impetus for the development of MAPPS. The simulation nature of the model along with its generous input parameters and output variables allows its usefulness to extend beyond its input to PRA

  7. Maintenance of the classroom health education curricula: results from the CATCH-ON study.

    Science.gov (United States)

    Johnson, Carolyn C; Li, Donglin; Galati, Todd; Pedersen, Sheryl; Smyth, Mary; Parcel, Guy S

    2003-08-01

    Maintenance of the interactive Child and Adolescent Trial for Cardiovascular Health (CATCH) third- to fifth-grade curricula was studied in the 56 original intervention schools and 20 of the original control schools 5 years postintervention in four regions of the United States. Target grade teachers completed a self-administered survey that included questions regarding use of the CATCH materials, training in CATCH or other health education, barriers and perceived support for health education, and amount of health education currently taught. Percentage of teachers who continued to teach CATCH in the classroom was low; however, percentages were significantly higher in former intervention compared with control schools, even though control schools received training and materials following the main field trial. The results of this study can provide useful information for future development of classroom health promotion materials with a higher level of sustainability.

  8. Health care utilization and cost among children with asthma who were enrolled in a health maintenance organization.

    Science.gov (United States)

    Lozano, P; Fishman, P; VonKorff, M; Hecht, J

    1997-06-01

    To measure the impact of asthma on the use and cost of health care by children in a managed care organization. Population-based historical cohort study. A medium-sized staff model health maintenance organization in western Washington state. All 71 818 children, between age 1 to 17 years, who were enrolled and used services during 1992. Children were identified with one or more asthma diagnoses during 1992 using automated encounter data. Nonurgent outpatient visits, pharmacy fills, urgent care visits, and hospital days, as well as associated costs were measured. All services were categorized as asthma care or nonasthma care. Multivariate regression analysis was used to compute marginal cost for asthma (difference in total cost between children with asthma and other children using services, adjusted for covariates). Treated prevalence of asthma was 4.9%. Children with asthma incurred 88% more costs ($1060.32 vs $563. 81/yr), filled 2.77 times as many prescriptions (11.59 vs 4.19/yr), made 65% more nonurgent outpatient visits (5.75 vs 3.48/yr), and had twice as many inpatient days (.23 vs .11/yr) compared with the general population of children using services. Asthma care represented 37% of all health care received by children with asthma, while the remaining 63% were for nonasthma services. Almost two-thirds of asthma-related costs were attributable to nonurgent outpatient care and prescriptions; only one third was attributable to urgent care and hospitalizations. Controlling for age, sex, and comorbidities, the marginal cost of asthma was $615.17/yr (95% confidence interval $502.73, $727.61), which includes asthma as well as nonasthma services. This marginal cost represents 58% of all health care costs for children with asthma. Children with asthma use significantly more health services (and incur significantly more costs) than other children using services, attributable largely to asthma care. The majority of all health care costs for children with asthma were for

  9. 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.

  10. Product differentiation among health maintenance organizations: causes and consequences of offering open-ended products.

    Science.gov (United States)

    Wholey, D R; Christianson, J B

    1994-01-01

    Open-ended products that allow an HMO enrollee to use providers who are not affiliated with the HMO have become an important component of the Clinton administration's health reform proposal, because these products maintain consumer freedom of choice of any provider. However, little is known about the consequences of offering an open-ended product from an organizational standpoint. This paper uses a theory of "spatial competition" to examine the decisions of health maintenance organizations to offer an open-ended product and the effect of offering an open-ended product on their enrollment.

  11. Inequalities in maintenance of health and performance between young adult women and men in higher education.

    Science.gov (United States)

    Löve, Jesper; Dellve, Lotta; Eklöf, Mats; Hagberg, Mats

    2009-04-01

    Because of ageing populations, most high-income countries are facing an imminent scarcity of labour. Maintenance of health and performance in young adults therefore becomes a crucial prerequisite for sustainable societies. One major obstruction to this accomplishment is the striking health inequalities between young women and young men. Previously these inequalities have mainly been studied in a cross-sectional way, focusing on ill-health. In this study, we compared the prevalence of maintained health and performance between young adult women and men and the predictors for this outcome. The cohort consisted of 1266 participants from a homogenous sample of university students in Sweden. A combined assessment of self-rated 'very good' health and un-impaired performance took place at three time points (i.e. maintained health and performance). Potential predictors covered stable conditions in health-related behaviours, conditions at work/school and work-home interference. Young women had less maintained health and performance than young men. No major differences in predictors were found. However, there was a tendency for psychosocial factors to be the most important predictors, especially in women. That young women had less maintained health and performance in a homogenous sample beyond well-known differentiating factors suggests explanations other than observable structural differences between the sexes. This was also indicated by the importance attached to perceived demands, and work-home interference, especially in women. The combination of less scheduled, and more unscheduled, schoolwork (i.e. time-flexibility) negatively affected the maintenance of health and performance in our study population, suggesting a focus for future studies.

  12. Multiobjective Optimization of Aircraft Maintenance in Thailand Using Goal Programming: A Decision-Support Model

    Directory of Open Access Journals (Sweden)

    Yuttapong Pleumpirom

    2012-01-01

    Full Text Available The purpose of this paper is to develop the multiobjective optimization model in order to evaluate suppliers for aircraft maintenance tasks, using goal programming. The authors have developed a two-step process. The model will firstly be used as a decision-support tool for managing demand, by using aircraft and flight schedules to evaluate and generate aircraft-maintenance requirements, including spare-part lists. Secondly, they develop a multiobjective optimization model by minimizing cost, minimizing lead time, and maximizing the quality under various constraints in the model. Finally, the model is implemented in the actual airline's case.

  13. Health Information Sources, Perceived Vaccination Benefits, and Maintenance of Childhood Vaccination Schedules.

    Science.gov (United States)

    Hwang, Juwon; Shah, Dhavan V

    2018-06-05

    Parental concerns over the safety or necessity of childhood vaccination have increased over the past decades. At the same time, there has been a proliferation of vaccine-related information available through a range of health information sources. This study investigates the associations between evaluations of health information sources, parental perceptions of childhood vaccination benefits, and the maintenance of vaccination schedules for their children. Specifically, this study aims to (a) incorporate social media into the battery of health information sources and (b) differentiate households with a childhood autism diagnosis and those without, given unsubstantiated but persistent concerns about vaccine safety and autism. Analyzing a sample of U.S. households, a total of 4,174 parents who have at least one child under the age of 18 were analyzed, including 138 of parents of households with a childhood autism diagnosis. Results show that the more the parents value interpersonal communication and magazines as sources of health information, the more they perceive vaccination benefits, and the more the value they put on television, the better they keep vaccination schedules up-to-date for their children. On the other hand, social media are negatively associated with their perceptions of vaccination benefits. Although parents of children diagnosed with autism are less likely to perceive vaccination benefits, no interaction effects with evaluations of health information sources are found on parental perceptions of vaccination benefits or maintenance of schedules.

  14. DEVELOPMENT OF MATHEMATICAL MODELS FOR OPTIMAL PREVENTIVE MAINTENANCE POLICY IN A STEEL INDUSTRY : SIX SIGMA APPROACH

    Directory of Open Access Journals (Sweden)

    N. V. R. Naidu

    2011-09-01

    Full Text Available This paper deals with a critical evaluation of the Preventive Maintenance system in steel industry. This study helps in implementing Six Sigma solutions to reduce the down time of two critical machines i.e., Electric Arc Furnace (EAF and Billet Casting Machine (BCM. It is clear from the analysis of EAF and BCM respectively that, variations in output are quite possible because the machines output not only depend on maintenance time but also on several other variables. Further, the objective is to design a preventive maintenance programme on the same equipment situated in the plant using Six Sigma. The breakdown of these equipments could very well affect the production rate. For this, the mathematical models have been developed and these models are used to obtain the optimum preventive maintenance frequency for minimizing the down time and maximizing the profits.

  15. The Maintenance Personnel Performance Simulation (MAPPS) model: A human reliability analysis tool

    International Nuclear Information System (INIS)

    Knee, H.E.

    1985-01-01

    The Maintenance Personnel Performance Simulation (MAPPS) model is a computerized, stochastic, task-oriented human behavioral model developed to provide estimates of nuclear power plant (NPP) maintenance team performance measures. It is capable of addressing person-machine, person-environment, and person-person relationships, and accounts for interdependencies that exist between the subelements that make up the maintenance task of interest. The primary measures of performance estimated by MAPPS are: 1) the probability of successfully completing the task of interest and 2) the task duration time. MAPPS also estimates a host of other performance indices, including the probability of an undetected error, identification of the most- and least-likely error-prone subelements, and maintenance team stress profiles during task execution

  16. 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.

  17. Modelling maintenance practice of production plant using the delay-time concept

    NARCIS (Netherlands)

    Christer, A.H.; Wang, Wenbin; Baker, R.D.; Sharp, J.

    1995-01-01

    In this paper we present a study carried out for a copper products manufacturing company, developing and applying the delay-time modelling technique to model and thus optimize preventive maintenance (PM) of the plant. A key machine in the plant is used to illustrate the modelling process and

  18. 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...

  19. 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...

  20. 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...

  1. Barriers to accessing and using health insurance cards among methadone maintenance treatment patients in northern Vietnam.

    Science.gov (United States)

    Tran, Bach Xuan; Boggiano, Victoria L; Nguyen, Cuong Tat; Nguyen, Long Hoang; Le Nguyen, Anh Tuan; Latkin, Carl A

    2017-07-17

    Methadone maintenance treatment (MMT) patients face unique costs associated with their healthcare expenditures. As such, it is important that these patients have access to health insurance (HI) to help them pay for both routine and unforeseen health services. In this study, we explored factors related to health insurance enrollment and utilization among MMT patients, to move Vietnam closer to universal coverage among this patient population. A cross-sectional study was conducted with 1003 patients enrolled in MMT in five clinics in Hanoi and Nam Dinh provinces. Patients were asked a range of questions about their health, health expenditures, and health insurance access and utilization. We used multivariate logistic regressions to determine factors associated with health insurance access among participants. The majority of participants (nearly 80%) were not currently enrolled in health insurance at the time of the study. Participants from rural regions were significantly more likely than urban participants to report difficulty using HI. Family members of participants from rural regions were more likely to have overall poor service quality through health insurance compared with family members of participants from urban regions. Overall, 37% of participants endorsed a lack of information about HI, nearly 22% of participants reported difficulty accessing HI, 22% reported difficulty using HI, and more than 20% stated they had trouble paying for HI. Older, more highly educated, and employed participants were more likely to have an easier time accessing HI than their younger, less well educated, and unemployed counterparts. HIV-positive participants were more likely to have sufficient information about health insurance options. Our study highlights the dearth of health insurance utilization among MMT patients in northern Vietnam. It also sheds light on factors associated with increased access to and utilization of health insurance among this underserved population. These

  2. A heuristic model for risk and cost impacts of plant outage maintenance schedule

    International Nuclear Information System (INIS)

    Mohammad Hadi Hadavi, S.

    2009-01-01

    Cost and risk are two major competing criteria in maintenance optimization problems. If a plant is forced to shutdown because of accident or fear of accident happening, beside loss of revenue, it causes damage to the credibility and reputation of the business operation. In this paper a heuristic model for incorporating three compelling optimization criteria (i.e., risk, cost, and loss) into a single evaluation function is proposed. Such a model could be used in any evaluation engine of outage maintenance schedule optimizer. It is attempted to make the model realistic and to address the ongoing challenges facing a schedule planner in a simple and commonly understandable fashion. Two simple competing schedules for the NPP feedwater system are examined against the model. The results show that while the model successfully addresses the current challenges for outage maintenance optimization, it properly demonstrates the dynamics of schedule in regards to risk, cost, and losses endured by maintenance schedule, particularly when prolonged outage and lack of maintenance for equipments in need of urgent care are of concern.

  3. 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.

  4. Modeling the reliability and maintenance costs of wind turbines using Weibull analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vachon, W.A. [W.A. Vachon & Associates, Inc., Manchester, MA (United States)

    1996-12-31

    A general description is provided of the basic mathematics and use of Weibull statistical models for modeling component failures and maintenance costs as a function of time. The applicability of the model to wind turbine components and subsystems is discussed with illustrative examples of typical component reliabilities drawn from actual field experiences. Example results indicate the dominant role of key subsystems based on a combination of their failure frequency and repair/replacement costs. The value of the model is discussed as a means of defining (1) maintenance practices, (2) areas in which to focus product improvements, (3) spare parts inventory, and (4) long-term trends in maintenance costs as an important element in project cash flow projections used by developers, investors, and lenders. 6 refs., 8 figs., 3 tabs.

  5. Maintenance Personnel Performance Simulation (MAPPS) model. Users' Manual

    International Nuclear Information System (INIS)

    Kopstein, F.F.; Wolf, J.J.

    1985-09-01

    This report (MAPPS User's Manual) is the last report to be published from this program and provides detailed guidelines for utilization of the MAPPS model. Although the model has been developed to be highly user-friendly and provides interactive means for controlling and running of the model, the user's manual is provided as a guide for the user in the event clarification or direction is required. The user will find that in general the model requires primarily user input that is self explanatory. Once initial familiarization with the model has been achieved by the user, the amount of interaction between the user's manual and the computer model will be minimal. It is suggested however that even the experienced user keep the user's manual handy for quick reference. 5 refs., 10 figs., 7 tabs

  6. Pricing and performance in health maintenance organizations: a strategic management perspective.

    Science.gov (United States)

    Conant, J S; Mokwa, M P; Burnett, J J

    1989-03-01

    Innovative, consumer-oriented pricing strategies have contributed to the impressive growth of health maintenance organizations (HMOs). In a national study of HMO marketing directors, the relationships between strategic management style and (1) the relative importance of pricing in competitive marketing strategy, (2) the effectiveness of price strategy planning, and (3) financial performance are examined. The findings indicate that HMOs practicing effective price planning also perform well on an overall basis. Insight into the content and substance of HMO pricing strategies is also provided.

  7. Operational health and physics service during the maintenance of the Australian National Medical Cyclotron

    International Nuclear Information System (INIS)

    Mukherjee, B.

    1994-01-01

    Modern Medical Cyclotrons use intense beams of high energy protons or deuterons to produce large activities of short and medium lived radionuclides. After continuous operation for prolonged periods the Cyclotron components become activated through various nuclear interactions therefore, the risk of personal radiation hazard while handling such activated cyclotron components is high. This paper describes all operational aspects of the Health Physics service evolved during the first preventative maintenance program of the Australian National Medical Cyclotron, which took place in June 1993. 5 refs., 3 tabs., 2 figs

  8. Computer-Aided Template for Model Reuse, Development and Maintenance

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul

    2014-01-01

    A template-based approach for model development is presented in this work. Based on a model decomposition technique, the computer-aided template concept has been developed. This concept is implemented as a software tool , which provides a user-friendly interface for following the workflow steps...

  9. A maintenance and operations cost model for DSN

    Science.gov (United States)

    Burt, R. W.; Kirkbride, H. L.

    1977-01-01

    A cost model for the DSN is developed which is useful in analyzing the 10-year Life Cycle Cost of the Bent Pipe Project. The philosophy behind the development and the use made of a computer data base are detailed; the applicability of this model to other projects is discussed.

  10. A Context Maintenance and Retrieval Model of Organizational Processes in Free Recall

    Science.gov (United States)

    Polyn, Sean M.; Norman, Kenneth A.; Kahana, Michael J.

    2009-01-01

    The authors present the context maintenance and retrieval (CMR) model of memory search, a generalized version of the temporal context model of M. W. Howard and M. J. Kahana (2002a), which proposes that memory search is driven by an internally maintained context representation composed of stimulus-related and source-related features. In the CMR…

  11. An integrated model of statistical process control and maintenance based on the delayed monitoring

    International Nuclear Information System (INIS)

    Yin, Hui; Zhang, Guojun; Zhu, Haiping; Deng, Yuhao; He, Fei

    2015-01-01

    This paper develops an integrated model of statistical process control and maintenance decision. The proposal of delayed monitoring policy postpones the sampling process till a scheduled time and contributes to ten-scenarios of the production process, where equipment failure may occur besides quality shift. The equipment failure and the control chart alert trigger the corrective maintenance and the predictive maintenance, respectively. The occurrence probability, the cycle time and the cycle cost of each scenario are obtained by integral calculation; therefore, a mathematical model is established to minimize the expected cost by using the genetic algorithm. A Monte Carlo simulation experiment is conducted and compared with the integral calculation in order to ensure the analysis of the ten-scenario model. Another ordinary integrated model without delayed monitoring is also established as comparison. The results of a numerical example indicate satisfactory economic performance of the proposed model. Finally, a sensitivity analysis is performed to investigate the effect of model parameters. - Highlights: • We develop an integrated model of statistical process control and maintenance. • We propose delayed monitoring policy and derive an economic model with 10 scenarios. • We consider two deterioration mechanisms, quality shift and equipment failure. • The delayed monitoring policy will help reduce the expected cost

  12. 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.

  13. A joint spare part and maintenance inspection optimisation model using the Delay-Time concept

    International Nuclear Information System (INIS)

    Wang Wenbin

    2011-01-01

    Spare parts and maintenance are closely related logistics activities where maintenance generates the need for spare parts. When preventive maintenance is present, it may need more spare parts at one time because of the planned preventive maintenance activities. This paper considers the joint optimisation of three decision variables, e.g., the ordering quantity, ordering interval and inspection interval. The model is constructed using the well-known Delay-Time concept where the failure process is divided into a two-stage process. The objective function is the long run expected cost per unit time in terms of the three decision variables to be optimised. Here we use a block-based inspection policy where all components are inspected at the same time regardless of the ages of the components. This creates a situation that the time to failure since the immediate previous inspection is random and has to be modelled by a distribution. This time is called the forward time and a limiting but closed form of such distribution is obtained. We develop an algorithm for the optimal solution of the decision process using a combination of analytical and enumeration approaches. The model is demonstrated by a numerical example. - Highlights: → Joint optimisation of maintenance and spare part inventory. → The use of the Delay-Time concept. → Block-based inspection. → Fixed order interval but variable order quantity.

  14. A proposed model for assessing service quality in small machining and industrial maintenance companies

    Directory of Open Access Journals (Sweden)

    Morvam dos Santos Netto

    2014-11-01

    Full Text Available Machining and industrial maintenance services include repair (corrective maintenance of equipments, activities involving the assembly-disassembly of equipments, fault diagnosis, machining operations, forming operations, welding processes, assembly and test of equipments. This article proposes a model for assessing the quality of services provided by small machining and industrial maintenance companies, since there is a gap in the literature regarding this issue and because the importance of small service companies in socio-economic development of the country. The model is an adaptation of the SERVQUAL instrument and the criteria determining the quality of services are designed according to the service cycle of a typical small machining and industrial maintenance company. In this sense, the Moments of Truth have been considered in the preparation of two separate questionnaires. The first questionnaire contains 24 statements that reflect the expectations of customers, and the second one contains 24 statements that measure perceptions of service performance. An additional item was included in each questionnaire to assess, respectively, the overall expectation about the services and the overall company performance. Therefore, it is a model that considers the interfaces of the client/supplier relationship, the peculiarities of the machining and industrial maintenance service sector and the company size.

  15. Context-Dependent Prognostics and Health Assessment: A Condition-Based Maintenance Approach That Supports Mission Compliance

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Kercel, S.W.

    1999-04-19

    In today's manufacturing environment, plants, systems, and equipment are being asked to perform at levels not thought possible a decade ago. The intent is to improve process operations and equipment reliability, availability, and maintainability without costly upgrades. Of course these gains must be achieved without impacting operational performance. Downsizing is also taking its toll on operations. Loss of personnel, particularly those who represent the corporate history, is depleting US industries of their valuable experiential base which has been relied on so heavily in the past. These realizations are causing companies to rethink their condition-based maintenance policies by moving away from reacting to equipment problems to taking a proactive approach by anticipating needs based on market and customer requirements. This paper describes a different approach to condition-based maintenance-context-dependent prognostics and health assessment. This diagnostic capability is developed around a context-dependent model that provides a capability to anticipate impending failures and determine machine performance over a protracted period of time. This prognostic capability links operational requirements to an economic performance model. In this context, a system may provide 100% operability with less than 100% functionality. This paradigm is used to facilitate optimal logistic supply and support.

  16. A Markov deterioration model for predicting recurrent maintenance ...

    African Journals Online (AJOL)

    The parameters of the Markov chain model for predicting the condition of the road at a design · period for· the flexible pavement failures of wheel track rutting, cracks and pot holes were developed for the Niger State· road network . in Nigeria. Twelve sampled candidate roads were each subjected to standard inventory, traffic ...

  17. Maintenance overtime policies in reliability theory models with random working cycles

    CERN Document Server

    Nakagawa, Toshio

    2015-01-01

    This book introduces a new concept of replacement in maintenance and reliability theory. Replacement overtime, where replacement occurs at the first completion of a working cycle over a planned time, is a new research topic in maintenance theory and also serves to provide a fresh optimization technique in reliability engineering. In comparing replacement overtime with standard and random replacement techniques theoretically and numerically, 'Maintenance Overtime Policies in Reliability Theory' highlights the key benefits to be gained by adopting this new approach and shows how they can be applied to inspection policies, parallel systems and cumulative damage models. Utilizing the latest research in replacement overtime by internationally recognized experts, readers are introduced to new topics and methods, and learn how to practically apply this knowledge to actual reliability models. This book will serve as an essential guide to a new subject of study for graduate students and researchers and also provides a...

  18. 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.

  19. Age-dependent reliability model considering effects of maintenance and working conditions

    International Nuclear Information System (INIS)

    Martorell, Sebastian; Sanchez, Ana; Serradell, Vicente

    1999-01-01

    Nowadays, there is some doubt about building new nuclear power plants (NPPs). Instead, there is a growing interest in analyzing the possibility to extend current NPP operation, where life management programs play an important role. The evolution of the NPP safety depends on the evolution of the reliability of its safety components, which, in turn, is a function of their age along the NPP operational life. In this paper, a new age-dependent reliability model is presented, which includes parameters related to surveillance and maintenance effectiveness and working conditions of the equipment, both environmental and operational. This model may be used to support NPP life management and life extension programs, by improving or optimizing surveillance and maintenance tasks using risk and cost models based on such an age-dependent reliability model. The results of the sensitivity study in the example application show that the selection of the most appropriate maintenance strategy would directly depend on the previous parameters. Then, very important differences are expected to appear under certain circumstances, particularly, in comparison with other models that do not consider maintenance effectiveness and working conditions simultaneously

  20. A continuum mathematical model of endothelial layer maintenance and senescence

    Directory of Open Access Journals (Sweden)

    Friedman Avner

    2007-08-01

    Full Text Available Abstract Background The monolayer of endothelial cells (ECs lining the inner wall of blood vessels deteriorates as a person ages due to a complex interplay of a variety of causes including cell death arising from shear stress of blood flow and cellular oxidative stress, cellular senescence, and decreased rate of replacement of dead ECs by progenitor stem cells. Results A continuum mathematical model is developed to describe the dynamics of large EC populations of the endothelium using a system of differential equations for the number densities of cells of different generations starting from endothelial progenitors to senescent cells, as well as the densities of dead cells and the holes created upon clearing dead cells. Aging of cells is manifested in three ways, namely, losing the ability to divide when the Hayflick limit of 50 generations is reached, decreasing replication rate parameters and increasing death rate parameters as cells divide; due to the dependence of these rate parameters on cell generation, the model predicts a narrow distribution of cell densities peaking at a particular cell generation. As the chronological age of a person advances, the peak of the distribution – corresponding to the age of the endothelium – moves towards senescence correspondingly. However, computer simulations also demonstrate that sustained and enhanced stem cell homing can halt the aging process of the endothelium by maintaining a stationary cell density distribution that peaks well before the Hayflick limit. The healing rates of damaged endothelia for young, middle-aged, and old persons are compared and are found to be particularly sensitive to the stem cell homing parameter. Conclusion The proposed model describes the aging of the endothelium as being driven by cellular senescence, with a rate that does not necessarily correspond to the chronological aging of a person. It is shown that the age of the endothelium depends sensitively on the homing

  1. A continuum mathematical model of endothelial layer maintenance and senescence.

    Science.gov (United States)

    Wang, Ying; Aguda, Baltazar D; Friedman, Avner

    2007-08-10

    The monolayer of endothelial cells (ECs) lining the inner wall of blood vessels deteriorates as a person ages due to a complex interplay of a variety of causes including cell death arising from shear stress of blood flow and cellular oxidative stress, cellular senescence, and decreased rate of replacement of dead ECs by progenitor stem cells. A continuum mathematical model is developed to describe the dynamics of large EC populations of the endothelium using a system of differential equations for the number densities of cells of different generations starting from endothelial progenitors to senescent cells, as well as the densities of dead cells and the holes created upon clearing dead cells. Aging of cells is manifested in three ways, namely, losing the ability to divide when the Hayflick limit of 50 generations is reached, decreasing replication rate parameters and increasing death rate parameters as cells divide; due to the dependence of these rate parameters on cell generation, the model predicts a narrow distribution of cell densities peaking at a particular cell generation. As the chronological age of a person advances, the peak of the distribution - corresponding to the age of the endothelium - moves towards senescence correspondingly. However, computer simulations also demonstrate that sustained and enhanced stem cell homing can halt the aging process of the endothelium by maintaining a stationary cell density distribution that peaks well before the Hayflick limit. The healing rates of damaged endothelia for young, middle-aged, and old persons are compared and are found to be particularly sensitive to the stem cell homing parameter. The proposed model describes the aging of the endothelium as being driven by cellular senescence, with a rate that does not necessarily correspond to the chronological aging of a person. It is shown that the age of the endothelium depends sensitively on the homing rates of EC progenitor cells.

  2. Human cognitive task distribution model for maintenance support system of a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Ho

    2007-02-15

    In human factors research, more attention has been devoted to the operation of nuclear power plants (NPPs) than to their maintenance. However, human error related to maintenance is 45% among the total human errors from 1990 to 2005 in Korean nuclear power plants. Therefore, it is necessary to study human factors in the maintenance of an NPP. There is a current trend toward introducing digital technology into both safety and non-safety systems in NPPs. A variety of information about plant conditions can be used digitally. In the future, maintenance support systems will be developed based on an information-oriented NPP. In this context, it is necessary to study the cognitive tasks of the personnel involved in maintenance and the interaction between the personnel and maintenance support systems. The fundamental purpose of this work is how to distribute the cognitive tasks of the personnel involved in the maintenance in order to develop a maintenance support system that considers human factors. The second purpose is to find the causes of errors due to engineers or maintainers and propose system functions that are countermeasures to reduce these errors. In this paper, a cognitive task distribution model of the personnel involved in maintenance is proposed using Rasmussen's decision making model. First, the personnel were divided into three groups: the operators (inspectors), engineers, and maintainers. Second, human cognitive tasks related to maintenance were distributed based on these groups. The operators' cognitive tasks are detection and observation; the engineers' cognitive tasks are identification, evaluation, target state, select target, and procedure: and the maintainers' cognitive task is execution. The case study is an analysis of failure reports related to human error in maintenance over a period of 15years. By using error classification based on the information processing approach, the human errors involved in maintenance were classified

  3. Human cognitive task distribution model for maintenance support system of a nuclear power plant

    International Nuclear Information System (INIS)

    Park, Young Ho

    2007-02-01

    In human factors research, more attention has been devoted to the operation of nuclear power plants (NPPs) than to their maintenance. However, human error related to maintenance is 45% among the total human errors from 1990 to 2005 in Korean nuclear power plants. Therefore, it is necessary to study human factors in the maintenance of an NPP. There is a current trend toward introducing digital technology into both safety and non-safety systems in NPPs. A variety of information about plant conditions can be used digitally. In the future, maintenance support systems will be developed based on an information-oriented NPP. In this context, it is necessary to study the cognitive tasks of the personnel involved in maintenance and the interaction between the personnel and maintenance support systems. The fundamental purpose of this work is how to distribute the cognitive tasks of the personnel involved in the maintenance in order to develop a maintenance support system that considers human factors. The second purpose is to find the causes of errors due to engineers or maintainers and propose system functions that are countermeasures to reduce these errors. In this paper, a cognitive task distribution model of the personnel involved in maintenance is proposed using Rasmussen's decision making model. First, the personnel were divided into three groups: the operators (inspectors), engineers, and maintainers. Second, human cognitive tasks related to maintenance were distributed based on these groups. The operators' cognitive tasks are detection and observation; the engineers' cognitive tasks are identification, evaluation, target state, select target, and procedure: and the maintainers' cognitive task is execution. The case study is an analysis of failure reports related to human error in maintenance over a period of 15years. By using error classification based on the information processing approach, the human errors involved in maintenance were classified

  4. Stochastic reliability and maintenance modeling essays in honor of Professor Shunji Osaki on his 70th birthday

    CERN Document Server

    Nakagawa, Toshio

    2013-01-01

    In honor of the work of Professor Shunji Osaki, Stochastic Reliability and Maintenance Modeling provides a comprehensive study of the legacy of and ongoing research in stochastic reliability and maintenance modeling. Including associated application areas such as dependable computing, performance evaluation, software engineering, communication engineering, distinguished researchers review and build on the contributions over the last four decades by Professor Shunji Osaki. Fundamental yet significant research results are presented and discussed clearly alongside new ideas and topics on stochastic reliability and maintenance modeling to inspire future research. Across 15 chapters readers gain the knowledge and understanding to apply reliability and maintenance theory to computer and communication systems. Stochastic Reliability and Maintenance Modeling is ideal for graduate students and researchers in reliability engineering, and workers, managers and engineers engaged in computer, maintenance and management wo...

  5. A review of multi-component maintenance models with economic dependence

    NARCIS (Netherlands)

    R. Dekker (Rommert); R.E. Wildeman (Ralph); F.A. van der Duyn Schouten (Frank)

    1997-01-01

    textabstractIn this paper we review the literature on multi-component maintenance models with economic dependence. The emphasis is on papers that appeared after 1991, but there is an overlap with Section 2 of the most recent review paper by Cho and Parlar (1991). We distinguish between stationary

  6. Interpretive Structural Model of Key Performance Indicators for Sustainable Maintenance Evaluatian in Rubber Industry

    Science.gov (United States)

    Amrina, E.; Yulianto, A.

    2018-03-01

    Sustainable maintenance is a new challenge for manufacturing companies to realize sustainable development. In this paper, an interpretive structural model is developed to evaluate sustainable maintenance in the rubber industry. The initial key performance indicators (KPIs) is identified and derived from literature and then validated by academic and industry experts. As a result, three factors of economic, social, and environmental dividing into a total of thirteen indicators are proposed as the KPIs for sustainable maintenance evaluation in rubber industry. Interpretive structural modeling (ISM) methodology is applied to develop a network structure model of the KPIs consisting of three levels. The results show the economic factor is regarded as the basic factor, the social factor as the intermediate factor, while the environmental factor indicated to be the leading factor. Two indicators of social factor i.e. labor relationship, and training and education have both high driver and dependence power, thus categorized as the unstable indicators which need further attention. All the indicators of environmental factor and one indicator of social factor are indicated as the most influencing indicator. The interpretive structural model hoped can aid the rubber companies in evaluating sustainable maintenance performance.

  7. Automotive Maintenance Data Base for Model Years 1976-1979. Part II : Appendix E and F

    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...

  8. A model for determining condition-based maintenance policies for deteriorating multi-component systems

    NARCIS (Netherlands)

    Hontelez, J.A.M.; Wijnmalen, D.J.D.

    1993-01-01

    We discuss a method to determine strategies for preventive maintenance of systems consisting of gradually deteriorating components. A model has been developed to compute not only the range of conditions inducing a repair action, but also inspection moments based on the last known condition value so

  9. 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...

  10. Development of predictive models for estimating warfarin maintenance dose based on genetic and clinical factors.

    Science.gov (United States)

    Yang, Lu; Linder, Mark W

    2013-01-01

    In this chapter, we use calculation of estimated warfarin maintenance dosage as an example to illustrate how to develop a multiple linear regression model to quantify the relationship between several independent variables (e.g., patients' genotype information) and a dependent variable (e.g., measureable clinical outcome).

  11. 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.

  12. 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.

  13. 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

  14. Model and Reduction of Inactive Times in a Maintenance Workshop Following a Diagnostic Error

    Directory of Open Access Journals (Sweden)

    T. Beda

    2011-04-01

    Full Text Available The majority of maintenance workshops in manufacturing factories are hierarchical. This arrangement permits quick response in advent of a breakdown. Reaction of the maintenance workshop is done by evaluating the characteristics of the breakdown. In effect, a diagnostic error at a given level of the process of decision making delays the restoration of normal operating state. The consequences are not just financial loses, but loss in customers’ satisfaction as well. The goal of this paper is to model the inactive time of a maintenance workshop in case that an unpredicted catalectic breakdown has occurred and a diagnostic error has also occurred at a certain level of decision-making, during the treatment process of the breakdown. We show that the expression for the inactive times obtained, is depended only on the characteristics of the workshop. Next, we propose a method to reduce the inactive times.

  15. Health and maintenance outages in nuclear power plants: an epidemiological survey

    International Nuclear Information System (INIS)

    Telle, M.A.; Huez, D.; Niedbala, J.M.; Auclair, J.; Canales, J.P.; Duverge, C.; Forest, H.; Gerondal, M.; Paris, P.M.; Renault, J.C.; Bossevain, L.; Blaise, P.; Blanc, M.C.; Goldberg, M.; Charpak, Y.

    1995-01-01

    An epidemiological survey, started in 1989, was carried out at the nuclear power plants in the Loire river valley and at Le Blayais (France). Working conditions, work organisation and their impact on health during annual maintenance outages were studied. The main areas covered in this cross-sectional study were: anxiety and symptoms of depression using the Spielberger and CES-D scales. Comparisons were made during both a scheduled outage and in normal operation on four distinct groups of workers, each individual being his own control. A chi-square test was used for the quantitative variables and a test on differences for the quantitative variables. During a unit outage, more frequent overtime and atypical working hours were reported (p<0.01); working rhythms and safety rules were felt as more restrictive and exposure to radiation higher (p<0.01). Detrimental modifications of anxiety and symptoms of depression were observed on controllers whereas expected on maintenance agents. Similar results were observed when considering the rates of outages. Possible readings are given with reference to qualitative studies carried out on this topic, which implies extending our research with both the quantitative and qualitative approaches. (authors). 10 refs., 6 tabs

  16. COSYMA: Health effects models

    International Nuclear Information System (INIS)

    Ehrhardt, J.

    1995-02-01

    As one of the main objectives of the MARIA project (''Methods for Assessing the Radiological Impact of Accidents'') initiated by the Commission of the European Communities the program package COSYMA (''COde SYstem from MARIA'') for assessing the radiological and economic off-site consequences of accidental releases of radioactive material to the atmosphere has been jointly developed by the Kernforschungszentrum Karlsruhe (KfK), FRG, and the National Radiological Protection Board (NRPB), UK. COSYMA includes models and data for assessing a broad spectrum of accident consequences, and they are implemented in independent modules. The subject of this report are those modules, which incorporate models and data for assessing individual and collective risks for deterministic and stochastic health effects. It describes the models implemented, the mathematical algorithms and the required data. Examples are given and explained for the input and output part of the modules. (orig.)

  17. Final report of MoReMO 2011-2012. Modelling resilience for maintenance and outage

    International Nuclear Information System (INIS)

    Gotcheva, N.; Macchi, L.; Oedewald, P.; Eitrheim, M.H.R.; Axelsson, C.; Reiman, T.; Pietikaeinen, E.

    2013-04-01

    The project Modelling Resilience for Maintenance and Outage (MoReMO) represents a two-year joint effort by VTT Technical Research Centre of Finland, Institute for Energy Technology (IFE, Norway) and Vattenfall (Sweden) to develop and test new approaches for safety management. The overall goal of the project was to present concepts on how resilience can be operationalized and built in a safety critical and socio-technical context. Furthermore, the project also aimed at providing guidance for other organizations that strive to develop and improve their safety performance in a business driven industry. We have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. During 2011 and 2012 the MoReMO project team has collected data through field observations, interviews, workshops, and document analysis on the work practices and adjustments in maintenance and outage in Nordic NPPs. The project consisted of two sub-studies, one focused on identifying and assessing adjustments and supporting resilient work practices in maintenance activities, while the other focused on handling performance trade-offs in maintenance and outage, as follows: A. Adjustments in maintenance work in Nordic nuclear power plants (VTT and Vattenfall). B. Handling performance trade-offs - the support of adaptive capacities (IFE and Vattenfall). The historical perspective of maintenance and outage management (Chapter 1.1) was provided by Vattenfall. Together, the two sub-studies have provided valuable insights for understanding the rationale behind work practices and adjustments, their effects on resilience, promoting flexibility and balancing between flexibility and reliability. (Author)

  18. Final report of MoReMO 2011-2012. Modelling resilience for maintenance and outage

    Energy Technology Data Exchange (ETDEWEB)

    Gotcheva, N.; Macchi, L.; Oedewald, P. [Technical Research Centre of Finland (VTT), Espoo (Finland); Eitrheim, M.H.R. [Institute for Energy Technology (IFE) (Norway); Axelsson, C.; Reiman, T.; Pietikaeinen, E. [Ringhals AB (NPP), Vattenfall AB (Sweden)

    2013-04-15

    The project Modelling Resilience for Maintenance and Outage (MoReMO) represents a two-year joint effort by VTT Technical Research Centre of Finland, Institute for Energy Technology (IFE, Norway) and Vattenfall (Sweden) to develop and test new approaches for safety management. The overall goal of the project was to present concepts on how resilience can be operationalized and built in a safety critical and socio-technical context. Furthermore, the project also aimed at providing guidance for other organizations that strive to develop and improve their safety performance in a business driven industry. We have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. During 2011 and 2012 the MoReMO project team has collected data through field observations, interviews, workshops, and document analysis on the work practices and adjustments in maintenance and outage in Nordic NPPs. The project consisted of two sub-studies, one focused on identifying and assessing adjustments and supporting resilient work practices in maintenance activities, while the other focused on handling performance trade-offs in maintenance and outage, as follows: A. Adjustments in maintenance work in Nordic nuclear power plants (VTT and Vattenfall). B. Handling performance trade-offs - the support of adaptive capacities (IFE and Vattenfall). The historical perspective of maintenance and outage management (Chapter 1.1) was provided by Vattenfall. Together, the two sub-studies have provided valuable insights for understanding the rationale behind work practices and adjustments, their effects on resilience, promoting flexibility and balancing between flexibility and reliability. (Author)

  19. 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

  20. Maintenance Personnel Performance Simulation (MAPPS) model: a human reliability analysis tool

    International Nuclear Information System (INIS)

    Knee, H.E.

    1985-01-01

    The Maintenance Personnel Performance Simulation (MAPPS) model is a computerized, stochastic, task-oriented human behavioral model developed to provide estimates of nuclear power plant (NPP) maintenance team performance measures. It is capable of addressing person-machine, person-environment, and person-person relationships, and accounts for interdependencies that exist between the subelements that make up the maintenance task of interest. The primary measures of performance estimated by MAPPS are: (1) the probability of successfully completing the task of interest; and (2) the task duration time. MAPPS also estimates a host of other performance indices, including the probability of an undetected error, identification of the most- and least-likely error-prone subelements, and maintenance team stress profiles during task execution. The MAPPS model was subjected to a number of evaluation efforts that focused upon its practicality, acceptability, usefulness, and validity. Methods used for these efforts included a case method approach, consensus estimation, and comparison with observed task performance measures at a NPP. Favorable results, such as close agreement between task duration times for two tasks observed in the field (67.0 and 119.8 minutes, respectively), and estimates by MAPPS (72.0 and 124.0 minutes, respectively) enhance the confidence in the future use of MAPPS. 8 refs., 1 fig

  1. Impact of forest maintenance on water shortages: Hydrologic modeling and effects of climate change.

    Science.gov (United States)

    Luo, Pingping; Zhou, Meimei; Deng, Hongzhang; Lyu, Jiqiang; Cao, Wenqiang; Takara, Kaoru; Nover, Daniel; Geoffrey Schladow, S

    2018-02-15

    The importance of water quantity for domestic and industrial water supply, agriculture, and the economy more broadly has led to the development of many water quantity assessment methods. In this study, surface flow and soil water in the forested upper reaches of the Yoshino River are compared using a distributed hydrological model with Forest Maintenance Module under two scenarios; before and after forest maintenance. We also examine the impact of forest maintenance on these variables during extreme droughts. Results show that surface flow and soil water increased after forest maintenance. In addition, projections of future water resources were estimated using a hydrological model and the output from a 20km mesh Global Climate Model (GCM20). River discharge for the near-future (2015-2039) is similar to that of the present (1979-2003). Estimated river discharge for the future (2075-2099) was found to be substantially more extreme than in the current period, with 12m 3 /s higher peak discharge in August and 7m 3 /s lower in July compared to the discharges of the present period. Soil water for the future is estimated to be lower than for the present and near future in May. The methods discussed in this study can be applied in other regions and the results help elucidate the impact of forests and climate change on water resources. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. 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.

  3. Criteria and model for assessing and improving information technology maturity within maintenance

    International Nuclear Information System (INIS)

    Kans, M; Ehsanifard, K; Moniri, A

    2012-01-01

    Maintenance optimization and decision-making processes have been both influenced considerably by Information Technology (IT) developments mainly by increasing data availability. The decision-making process in its turn has affected systems trustworthiness positively. Therefore, theoretically speaking it could be said that Maintenance Management Information technology (MMIT) has the potential to provide applicable solutions for many of the maintenance management problems. Nevertheless, this potential has been hardly experienced in practice because of the mismatch between the level of IT maturity in the organizations and their selected MMIT solutions. To fill this gap this paper suggests a number of criteria which are crucial in decision making for selecting a MMIT application. The criteria are formed based on previous findings utilising an extensive literature review. A model is further developed for this purpose which is also tested on a case company active in power generation in Sweden. The model proved to be helpful when taking further improvement steps for reaching high utilization of IT in maintenance.

  4. An economically designed, integrated quality and maintenance model using an adaptive Shewhart chart

    International Nuclear Information System (INIS)

    Panagiotidou, Sofia; Nenes, George

    2009-01-01

    This paper proposes a model for the economic design of a variable-parameter (Vp) Shewhart control chart used to monitor the mean in a process, where, apart from quality shifts, failures may also occur. Quality shifts result in poorer quality outcome, higher operational cost and higher failure rate. Thus, removal of such quality shifts, besides improving the quality of the outcome and reducing the quality cost, is also a preventive maintenance (PM) action since it reduces the probability of a failure and improves the equipment reliability. The proposed model allows the determination of the scheme parameters that minimize the total expected quality and maintenance cost of the procedure. The monitoring mechanism of the process employs an adaptive Vp-Shewhart control chart. To evaluate the effectiveness of the proposed model, its optimal expected cost is compared against the optimum cost of a fixed-parameter (Fp) chart

  5. Reliability and Maintainability model (RAM) user and maintenance manual. Part 2

    Science.gov (United States)

    Ebeling, Charles E.

    1995-01-01

    This report documents the procedures for utilizing and maintaining the Reliability and Maintainability Model (RAM) developed by the University of Dayton for the NASA Langley Research Center (LaRC). The RAM model predicts reliability and maintainability (R&M) parameters for conceptual space vehicles using parametric relationships between vehicle design and performance characteristics and subsystem mean time between maintenance actions (MTBM) and manhours per maintenance action (MH/MA). These parametric relationships were developed using aircraft R&M data from over thirty different military aircraft of all types. This report describes the general methodology used within the model, the execution and computational sequence, the input screens and data, the output displays and reports, and study analyses and procedures. A source listing is provided.

  6. Health maintenance organizations: critical issues raised by restructuring delivery for health systems reform.

    Science.gov (United States)

    Gold, M

    1993-10-01

    In sum, the potential that managed care will grow under health systems reform creates an opportunity for the HMO industry but also serves as a challenge and a threat. Faced with greater scrutiny and growing demands, HMOs increasingly are being forced to demonstrate their potential and live up to their expectation. At the same time, the changing nature of the health care system creates a challenge for HMOs. Cost pressures create needs to review the entire delivery system, including the ambulatory component, with a focus on enhancing cost-effectiveness. Greater visibility also creates demands; growing market penetration argues for the creation of a new paradigm to define an appropriate structure for public accountability and management. Finally, the transformation of an HMO industry into a managed care industry is not without its risks as HMO performance becomes evaluated not only against itself but as part of the performance of the broader managed care industry in which HMOs have become embedded.

  7. Predicting maintenance of attendance at walking groups: testing constructs from three leading maintenance theories.

    Science.gov (United States)

    Kassavou, Aikaterini; Turner, Andrew; Hamborg, Thomas; French, David P

    2014-07-01

    Little is known about the processes and factors that account for maintenance, with several theories existing that have not been subject to many empirical tests. The aim of this study was to test how well theoretical constructs derived from the Health Action Process Approach, Rothman's theory of maintenance, and Verplanken's approach to habitual behavior predicted maintenance of attendance at walking groups. 114 participants, who had already attended walking groups in the community for at least 3 months, completed a questionnaire assessing theoretical constructs regarding maintenance. An objective assessment of attendance over the subsequent 3 months was gained. Multilevel modeling was used to predict maintenance, controlling for clustering within walking groups. Recovery self-efficacy predicted maintenance, even after accounting for clustering. Satisfaction with social outcomes, satisfaction with health outcomes, and overall satisfaction predicted maintenance, but only satisfaction with health outcomes significantly predicted maintenance after accounting for clustering. Self-reported habitual behavior did not predict maintenance despite mean previous attendance being 20.7 months. Recovery self-efficacy, and satisfaction with health outcomes of walking group attendance appeared to be important for objectively measured maintenance, whereas self-reported habit appeared not to be important for maintenance at walking groups. The findings suggest that there is a need for intervention studies to boost recovery self-efficacy and satisfaction with outcomes of walking group attendance, to assess impact on maintenance.

  8. Towards an Information Model of Consistency Maintenance in Distributed Interactive Applications

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2008-01-01

    Full Text Available A novel framework to model and explore predictive contract mechanisms in distributed interactive applications (DIAs using information theory is proposed. In our model, the entity state update scheme is modelled as an information generation, encoding, and reconstruction process. Such a perspective facilitates a quantitative measurement of state fidelity loss as a result of the distribution protocol. Results from an experimental study on a first-person shooter game are used to illustrate the utility of this measurement process. We contend that our proposed model is a starting point to reframe and analyse consistency maintenance in DIAs as a problem in distributed interactive media compression.

  9. A MAINTENANCE STRATEGY MODEL FOR STATIC EQUIPMENT USING INSPECTION METHODOLOGIES AND RISK MANAGEMENT

    Directory of Open Access Journals (Sweden)

    J.K. Visser

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Mechanical equipment used on process plants can be categorised into two main types, namely static and rotating equipment. A brief survey at a number of chemical process plants indicated that a number of maintenance strategies exist and are used for rotating equipment. However, some of these strategies are not directly applicable to static equipment, although the risk-based inspection (RBI methodology has been developed for pressure vessels. A generalised risk-based maintenance strategy for all types of static equipment does not currently exist. This paper describes the development of an optimised model of inspection methodologies, maintenance strategies, and risk management principles that are generically applicable for static equipment. It enables maintenance managers and engineers to select an applicable maintenance strategy and inspection methodology, based on the operational and business risks posed by the individual pieces of equipment.

    AFRIKAANSE OPSOMMING: Meganiese toerusting wat op prosesaanlegte gebruik word kan in twee kategorieë verdeel word, naamlik statiese en roterende toerusting. 'n Bondige ondersoek by 'n aantal chemiese prosesaanlegte het aangedui dat 'n aantal strategieë vir instandhouding van roterende toerusting gebruik word, terwyl die risikogebaseerde inspeksiemetodologie wel vir drukvate gebruik word. 'n Algemene risikogebaseerde instandhoudingstrategie vir alle tipes statiese toerusting is egter nie tans beskikbaar nie. Hierdie artikel beskryf die ontwikkeling van 'n geoptimeerde model van inspeksiemetodologieë, instandhoudingstrategieë, en risikobestuursbeginsels wat algemeen gebruik kan word vir statiese toerusting. Dit stel die instandhouding-bestuurders en -ingenieurs in staat om 'n instandhoudingstrategie en inspeksie-metodologie te kies, gebaseer op die operasionele en besigheidsrisiko's van die individuele toerusting.

  10. 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.

  11. Molecular constraints on synaptic tagging and maintenance of long-term potentiation: a predictive model.

    Directory of Open Access Journals (Sweden)

    Paul Smolen

    Full Text Available Protein synthesis-dependent, late long-term potentiation (LTP and depression (LTD at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of protein kinase M ζ (PKMζ is thought essential for maintaining LTP. Additional spatial and temporal features that govern LTP and LTD induction are embodied in the synaptic tagging and capture (STC and cross capture hypotheses. Only synapses that have been "tagged" by a stimulus sufficient for LTP and learning can "capture" PKMζ. A model was developed to simulate the dynamics of key molecules required for LTP and LTD. The model concisely represents relationships between tagging, capture, LTD, and LTP maintenance. The model successfully simulated LTP maintained by persistent synaptic PKMζ, STC, LTD, and cross capture, and makes testable predictions concerning the dynamics of PKMζ. The maintenance of LTP, and consequently of at least some forms of long-term memory, is predicted to require continual positive feedback in which PKMζ enhances its own synthesis only at potentiated synapses. This feedback underlies bistability in the activity of PKMζ. Second, cross capture requires the induction of LTD to induce dendritic PKMζ synthesis, although this may require tagging of a nearby synapse for LTP. The model also simulates the effects of PKMζ inhibition, and makes additional predictions for the dynamics of CaM kinases. Experiments testing the above predictions would significantly advance the understanding of memory maintenance.

  12. Molecular constraints on synaptic tagging and maintenance of long-term potentiation: a predictive model.

    Science.gov (United States)

    Smolen, Paul; Baxter, Douglas A; Byrne, John H

    2012-01-01

    Protein synthesis-dependent, late long-term potentiation (LTP) and depression (LTD) at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of protein kinase M ζ (PKMζ) is thought essential for maintaining LTP. Additional spatial and temporal features that govern LTP and LTD induction are embodied in the synaptic tagging and capture (STC) and cross capture hypotheses. Only synapses that have been "tagged" by a stimulus sufficient for LTP and learning can "capture" PKMζ. A model was developed to simulate the dynamics of key molecules required for LTP and LTD. The model concisely represents relationships between tagging, capture, LTD, and LTP maintenance. The model successfully simulated LTP maintained by persistent synaptic PKMζ, STC, LTD, and cross capture, and makes testable predictions concerning the dynamics of PKMζ. The maintenance of LTP, and consequently of at least some forms of long-term memory, is predicted to require continual positive feedback in which PKMζ enhances its own synthesis only at potentiated synapses. This feedback underlies bistability in the activity of PKMζ. Second, cross capture requires the induction of LTD to induce dendritic PKMζ synthesis, although this may require tagging of a nearby synapse for LTP. The model also simulates the effects of PKMζ inhibition, and makes additional predictions for the dynamics of CaM kinases. Experiments testing the above predictions would significantly advance the understanding of memory maintenance.

  13. A guiding tool in Unani Tibb for maintenance and preservation of health: a review study.

    Science.gov (United States)

    Jabin, Farkhunda

    2011-01-01

    Unani Tibb is a holistic traditional system of medicine. Ever since 1976, WHO has adopted its policy of promoting traditional medicine, Unani Medicine has enjoyed an upsurge of interest, especially in India, where it has been practiced as one of the Indian systems of medicine. Ali et al (2007) opined that "in Tibb, 'temperament' is a notion of primary importance, though a difficult theory as it indicates the properties of an atom, a molecule, a cell, a tissue, an organ and human body as a whole". Temperament of a person represents its physical constitution and tendencies. It is believed in Tibb that imbalance in temperament predisposes human body to various diseases by producing a biotic imbalance with in body. Causes of initial imbalance in temperament lies in more subtle elements of life like air, water, food, rest, activity, work, evacuation of wastes, sleep etc. To quote Bhika (2006a) "health can be preserved and maintained as long as overall quality of humours is in harmony with overall quality of the temperament of the individual and humoural balance is influenced by lifestyle factors." Hence temperament acts as a guiding force for maintenance and preservation of individuals' health.

  14. Nutraceuticals in Periodontal Health: A Systematic Review on the Role of Vitamins in Periodontal Health Maintenance.

    Science.gov (United States)

    Varela-López, Alfonso; Navarro-Hortal, María D; Giampieri, Francesca; Bullón, Pedro; Battino, Maurizio; Quiles, José L

    2018-05-20

    Periodontal disease, a relevant public health problem worldwide, is generally considered a common pathology of elderly people. In this respect, there is agreement about that nutritional status may be a modifying factor in the progression and healing of the periodontal tissues. Vitamins have been recommended as nutraceuticals for prevention and treatment of some pathological conditions, such as cardiovascular diseases, obesity or cancer. Thus, a systematic approach to determining how the different vitamin type could ameliorate periodontal risks or improve periodontal health is necessary to further the understanding of the potential benefits and risks of vitamins supplementation use. For this, a systematic review of English-written literature in PubMed until February 2018, which included both human and animal research on the relationship of each vitamin with periodontal disease, was conducted. Among all the analyzed vitamins those with antioxidant capacity and effects on immune system seem to be useful for prevention or improvement of periodontal disease, as well as those implicated in bone metabolism. In the first case, there are quite information in favor of various vitamins, mainly vitamin C, that is the most studied. In the second case, vitamin D seems to have the most relevant role.

  15. 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....

  16. Extended warranties, maintenance service and lease contracts modeling and analysis for decision-making

    CERN Document Server

    Murthy, D N Prabhakar

    2014-01-01

    Serving to unify the existing literature on extended warranties, maintenance service contracts and lease contracts, this book also presents a unique perspective on the topic focussed on cost analysis and decision-making from the perspectives of the parties involved. Using a game theoretic approach together with mathematical modelling, results are presented in an integrated manner with key topics that require further research highlighted in order to serve as a starting point for researchers (engineers and statisticians) who are interested in doing further work in these areas. Designed to assist practitioners (managers, engineers, applied statisticians) who are involved with extended warranties, maintenance service contracts and lease contracts, the book provides them with the models and techniques needed for proper cost analysis and effective decision-making. The book is also suitable for use as a reference text in industrial engineering, applied statistics, operations research and management.

  17. Development of Pavement Maintenance Management System (PMMS of Urban Road Network Using HDM-4 Model

    Directory of Open Access Journals (Sweden)

    Tanuj Chopra

    2017-04-01

    Full Text Available The aim of the study is to develop Pavement Maintenance Management System (PMMS for four road sections of urban road network (Patiala, Punjab, India using Highway Development and Management (HDM-4 model. The HDM-4 provides a deterministic approach in data input and process data of existing road condition, traffic volume and pavement composition to predict road deterioration as per the urban road conditions in terms of International Roughness Index (IRI value. This study presents the use of HDM-4 model for the computation of optimum Maintenance and Rehabilitation (M&R strategy for each road section and comparative study of scheduled and condition responsive M&R strategies. The results of present study will be useful for gaining better support for decision-makers for adequate and timely fund allocations for preservation of the urban road network.

  18. 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

  19. Reliability and Maintainability Model (RAM): User and Maintenance Manual. Part 2; Improved Supportability Analysis

    Science.gov (United States)

    Ebeling, Charles E.

    1996-01-01

    This report documents the procedures for utilizing and maintaining the Reliability & Maintainability Model (RAM) developed by the University of Dayton for the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC). The purpose of the grant is to provide support to NASA in establishing operational and support parameters and costs of proposed space systems. As part of this research objective, the model described here was developed. This Manual updates and supersedes the 1995 RAM User and Maintenance Manual. Changes and enhancements from the 1995 version of the model are primarily a result of the addition of more recent aircraft and shuttle R&M data.

  20. 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...

  1. The Development and Application of a Value-Driven Aircraft Maintenance Operations Performance Assessment Model combined with Real Options Analysis

    NARCIS (Netherlands)

    Goossens, H.G.; Beelaerts van Blokland, W.W.A.; Curran, R.

    2011-01-01

    This research paper presents the results from the development of an Aircraft Maintenance Operations Performance Assessment Model (AMOPAM). The AMOPAM is able to assess the differences in performance in between two different states or scenarios of aircraft maintenance operations and is able to

  2. Developing a theoretical maintenance model for disordered eating in Type 1 diabetes.

    Science.gov (United States)

    Treasure, J; Kan, C; Stephenson, L; Warren, E; Smith, E; Heller, S; Ismail, K

    2015-12-01

    According to the literature, eating disorders are an increasing problem for more than a quarter of people with Type 1 diabetes and they are associated with accentuated diabetic complications. The clinical outcomes in this group when given standard eating disorder treatments are disappointing. The Medical Research Council guidelines for developing complex interventions suggest that the first step is to develop a theoretical model. To review existing literature to build a theoretical maintenance model for disordered eating in people with Type 1 diabetes. The literature in diabetes relating to models of eating disorder (Fairburn's transdiagnostic model and the dual pathway model) and food addiction was examined and assimilated. The elements common to all eating disorder models include weight/shape concern and problems with mood regulation. The predisposing traits of perfectionism, low self-esteem and low body esteem and the interpersonal difficulties from the transdiagnostic model are also relevant to diabetes. The differences include the use of insulin mismanagement to compensate for breaking eating rules and the consequential wide variations in plasma glucose that may predispose to 'food addiction'. Eating disorder symptoms elicit emotionally driven reactions and behaviours from others close to the individual affected and these are accentuated in the context of diabetes. The next stage is to test the assumptions within the maintenance model with experimental medicine studies to facilitate the development of new technologies aimed at increasing inhibitory processes and moderating environmental triggers. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

  3. A modeling framework for deteriorating control system and predictive maintenance of actuators

    International Nuclear Information System (INIS)

    Langeron, Y.; Grall, A.; Barros, A.

    2015-01-01

    Actuators play a central role in industrial automation systems. They are costly, and therefore studying their dependability needs all attention. Usually, an actuator is inserted in a feedback control system, and its mission is to implement a control action delivered by a controller. In this paper, a monotonic actuator deterioration is considered and it is assumed that a relationship exists between the control action and the physical actuator's deterioration. A modeling framework is proposed including a non-decreasing stochastic degradation process driving the inability for an actuator to fully implement its role. The prognosis of the actuator's residual useful lifetime is derived and used to update the controller's setting. The controller reconfiguration completes the maintenance corrective and preventive actions. This new action is suggested as an alternative for maintenance strategy. - Highlights: • A degrading control system model is proposed focusing on actuator deterioration. • It is assumed a relationship between this degradation and its loss of efficiency. • The actuator RUL is quantified as a quantile of its conditional survival function. • RUL prognosis is used to reconfigure the control input law. • This new action is suggested as an alternative for maintenance strategy

  4. Ground Track Acquisition and Maintenance Maneuver Modeling for Low-Earth Orbit Satellite

    Directory of Open Access Journals (Sweden)

    Byoung-Sun Lee

    1997-12-01

    Full Text Available This paper presents a comprehensive analytical approach for determining key maneuver parameters associated with the acquisition and maintenance of the ground track for a low-earth orbit. A livearized model relating changes in the drift rate of the ground track directly to changes in the orbital semi-major axis is also developed. The effect of terrestrial atmospheric drag on the semi-major axis is also explored, being quantified through an analytical expression for the decay rate as a function of density. The non-singular Lagrange planetary equations, further simplified for nearly circular orbits, provide the desired relationships between the corrective in-plane impulsive velocity increments and the corresponding effects on the orbit elements. The resulting solution strategy offers excellent insight into the dynamics affecting the timing, magnitude, and frequency of these maneuvers. Simulations are executed for the ground track acquisition and maintenance maneuver as a pre-flight planning and analysis.

  5. A Decision Optimization Model for Leased Manufacturing Equipment with Warranty under Forecasting Production/Maintenance Problem

    Directory of Open Access Journals (Sweden)

    Zied Hajej

    2015-01-01

    Full Text Available Due to the expensive production equipment, many manufacturers usually lease production equipment with a warranty period during a finite leasing horizon, rather than purchasing them. The lease contract contains the possibility of obtaining an extended warranty for a given additional cost. In this paper, based on the forecasting production/maintenance optimization problem, we develop a mathematical model to study the lease contract with basic and extended warranty based on win-win relationship between the lessee and the lessor. The influence of the production rates in the equipment degradation consequently on the total cost by each side during the finite leasing horizon is stated in order to determine a theoretical condition under which a compromise-pricing zone exists under different possibilities of maintenance policies.

  6. Emergence and maintenance of menopause in humans: A game theory model.

    Science.gov (United States)

    Thouzeau, Valentin; Raymond, Michel

    2017-10-07

    Menopause, the permanent cessation of ovulation, occurs in women well before the end of their expected life span. Several adaptive hypotheses have been proposed to solve this evolutionary puzzle, each based on a possible fitness benefit derived from an early reproductive senescence, but no consensus has emerged. The construction of a game theory model allowed us to jointly study the main adaptive hypotheses in emergence and maintenance of menopause. Four classical hypotheses on the benefits of menopause were considered (decreased maternal mortality, increased grandmothering, decreased conflict over reproductive resources between older and younger females, and changes in their relatedness) plus a fifth one derived from a possible pleiotropic trade-off. Interestingly, the conditions for the emergence of menopause are more restrictive than those for its maintenance due to the social and familial changes induced by the occurrence of non-reproductive older women. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Drug addiction stigma in relation to methadone maintenance treatment by different service delivery models in Vietnam.

    Science.gov (United States)

    Tran, Bach Xuan; Vu, Phuong Bich; Nguyen, Long Hoang; Latkin, Sophia Knowlton; Nguyen, Cuong Tat; Phan, Huong Thu Thi; Latkin, Carl A

    2016-03-08

    The rapid expansion of methadone maintenance treatment (MMT) services has significantly improved health status and quality of life of patients. However, little is known about its impacts on addiction-related stigma and associated factors. A cross-sectional survey was conducted in 2013 in Vietnam's capital, Hanoi, and Nam Dinh province among 1016 methadone maintenance patients; 26.6 % at provincial AIDS centers (PAC) and 73.4 % at district health centers (DHC), respectively. Drug addiction history and related stigma, health status, MMT-related covariates, and sociodemographic characteristics were interviewed. More than one-sixth of the sample reported experiencing felt or enacted stigma, including Blame or Judgement (17.2 %), Shame (19.9 %), or Others' fear of HIV transmission (17.1 %). These proportions were higher in PACs than in DHCs, which are integrated with other HIV or general health care services. Very few patients reported being discriminated at the workplace (2.5 %) or at health care services (1.7 %); however, 15.6 % of patients at PACs and 10.6 % of patients at DHCs reported discrimination in their communities. Drug users taking MMT for longer periods were less likely to report felt stigma. Other factors associated with stigma against MMT patients included the lack of comprehensive services, higher education, presence of pain/discomfort, and anxiety/depression, self-reported HIV positive, and number of previous drug rehabilitation episodes. The study shows a high level of stigma against MMT patients and emphasizes the necessity to integrate MMT with comprehensive health and support services. Mass communication campaigns to reduce stigma against people with drug addiction and HIV/AIDS, as well as vocational trainings and jobs referrals for MMT patients, are needed to maximize the benefits of MMT programs in Vietnam.

  8. Job analysis of the maintenance supervisor and instrument and control supervisor positions for the nuclear power plant maintenance personnel reliability model

    International Nuclear Information System (INIS)

    Bartter, W.D.; Siegel, A.I.; Federman, P.J.

    1982-11-01

    The present report presents the results of an analysis of the jobs of maintenance mechanic supervisors and instrument and control technician supervisors in nuclear power plants. Such an analysis was considered to be a necessary step in defining the scope and focus of a model for predicting and analyzing nuclear power maintenance reliability. The model will focus upon tasks and subtasks performed by various job positions. The results of this job analysis, along with the results of a survey of user needs vis-a-vis such a model and the results of parallel analyses of the job of maintenance mechanics and of instrument and control technicians provide the sound foundation on which such a model may be built. Job analysis possesses implications for a number of purposes. It provides insight into selection standards, job structuring and organization, performance analysis, training objective establishment, and training content derivation. Accordingly, the results of the present work possess implications for a variety of interest areas relative to safe and efficient operation of nuclear power plants

  9. The smoker's health project: a self-determination theory intervention to facilitate maintenance of tobacco abstinence.

    Science.gov (United States)

    Williams, Geoffrey C; Patrick, Heather; Niemiec, Christopher P; Ryan, Richard M; Deci, Edward L; Lavigne, Holly McGregor

    2011-07-01

    A previous randomized clinical trial based on self-determination theory (SDT) and consistent with the Public Health Service (PHS) Guideline for Treating Tobacco Use and Dependence demonstrated that an intensive intervention could change autonomous self-regulation and perceived competence, which in part facilitated long-term tobacco abstinence. The current article describes a pragmatic comparative effectiveness trial of three SDT-based intensive tobacco-dependence interventions. Eligible participants are randomized to one of the three treatment conditions designed to facilitate long-term maintenance of tobacco abstinence, namely, Community Care (CC), which includes the 6 month SDT-based intervention previously shown to promote autonomous self-regulation, perceived competence, medication use, and tobacco abstinence; Extended Need Support (ENS), which extends the 6 month SDT-based intervention to 12 months and trains an important other to provide support for smokers' basic psychological needs; and Harm Reduction (HR), which provides extended need support and recommends medication use for participants who do not want to stop smoking completely within 30 days but who are willing to reduce their cigarette use by half. The primary outcome is 12 month prolonged abstinence from tobacco, which is assessed one year following termination of treatment (two years post-randomization). Secondary outcomes include 7- and 30 day point prevalence tobacco abstinence, number of days using smoking-cessation medication, change in autonomous self-regulation and perceived competence, and perceived need support from important others. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. The incidence of duodenal and gastric ulcers in a large health maintenance organization.

    Science.gov (United States)

    Kurata, J H; Honda, G D; Frankl, H

    1985-06-01

    We report the incidence of peptic ulcers (duodenal, pyloric canal, gastric, and combined) verified by radiologic, endoscopic, or surgical evidence in a large Health Maintenance Organization (HMO) in Los Angeles, California. For members age 15 and above, the peptic ulcer incidence rate was 0.86 per 1,000 person-years (p-y) (males 1.10, females 0.63). The male to female sex ratio was 1.7. Two hundred twenty-two duodenal, 17 pyloric canal, 89 gastric, and 21 combined first-time diagnosed ulcer cases were located. For duodenal and pyloric canal ulcer, the incidence rate for members age 15 and above was 0.58 per 1,000 p-y (males 0.76, females 0.40). For gastric ulcer, the incidence rate for members age 15 and above was 0.21 per 1,000 p-y (males 0.23, females 0.18). The combined ulcer rate was 0.05 per 1,000 p-y (males 0.07, females 0.02). Gastric ulcer rates were two times higher in 1980 than in 1977. Peptic ulcer age-specific incidence rates increased with age. Incidence rates were much lower than those reported in previous studies, but the gastric to duodenal ulcer ratio and the age and sex relation to ulcer incidence were similar to those previously reported.

  11. Extracting and analyzing ejection fraction values from electronic echocardiography reports in a large health maintenance organization.

    Science.gov (United States)

    Xie, Fagen; Zheng, Chengyi; Yuh-Jer Shen, Albert; Chen, Wansu

    2017-12-01

    The left ventricular ejection fraction value is an important prognostic indicator of cardiovascular outcomes including morbidity and mortality and is often used clinically to indicate severity of heart disease. However, it is usually reported in free-text echocardiography reports. We developed and validated a computerized algorithm to extract ejection fraction values from echocardiography reports and applied the algorithm to a large volume of unstructured echocardiography reports between 1995 and 2011 in a large health maintenance organization. A total of 621,856 echocardiography reports with a description of ejection fraction values or systolic functions were identified, of which 70 percent contained numeric ejection fraction values and the rest (30%) were text descriptions explicitly indicating the systolic left ventricular function. The 12.1 percent (16.0% for male and 8.4% for female) of these extracted ejection fraction values are <45 percent. Validation conducted based on a random sample of 200 reports yielded 95.0 percent sensitivity and 96.9 percent positive predictive value.

  12. Behavioral and quality-of-life outcomes in different service models for methadone maintenance treatment in Vietnam.

    Science.gov (United States)

    Tran, Bach Xuan; Nguyen, Long Hoang; Nong, Vuong Minh; Nguyen, Cuong Tat; Phan, Huong Thu Thi; Latkin, Carl A

    2016-02-02

    Integrating HIV/AIDS and methadone maintenance treatment (MMT) services with existing health care delivery system is critical in sustaining efforts to fight HIV/AIDS in large injection-driven epidemics. However, efficiency of different integrative service models is unknown. This study assessed behavioral and health-related quality-of-life (HRQOL) outcomes of MMT in four service delivery models and explored factors associated with these outcomes of interest. A cross-sectional survey was conducted in two HIV epicenters in Vietnam: Hanoi and Nam Dinh Province. All patients in five selected MMT clinics were invited to participate, and 1016 were interviewed (80-90% response rate). Respondents had a mean age of 35.8, taken MMT for average 16.5 months and 3.3% on MMT for 36-60 months. The MMT integrated with rural district health center (DHC) has the highest prevalence of concurrent drug use (11.3%). The percentage of condom use (last sexual intercourse) with primary and casual partners was lowest in the MMT at urban DHCs. Patients at the rural DHC reported very high proportions of pain/discomfort (37.8%), anxiety/depression (43.1%), and mobility (13.3%). In regression models, poorer HRQOL outcomes were found in MMT models in the rural areas or without general health care, and among those patients who were HIV positive, reported concurrent drug use, and had higher numbers of previous drug rehabilitation episodes. Mobility and anxiety/depression are factors that increased the likelihood of concurrent drug use among MMT patients. Outcomes of MMT were diverse across different integrative service models. Policies on rapid expansion of the MMT program in Vietnam should also emphasize on the integration with comprehensive health care services including psychological supports for patients.

  13. Health risk air-conditioning system; Insufficient maintenance increases the risk of illness. Gesundheitsrisiko Klimaanlagen; Unzureichende Wartung erhoeht das Erkrankungsrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1994-01-01

    In Germany every fifth employee who works in air-conditioned rooms complains about headache, an increased proneness to colds and influenza infections as well as allergic reactions. These troubles are often caused by the insufficient maintenance of air-conditioning systems. At present only 15% of the estimated annual demand for maintenance of space hvac-systems is actually carried out. Problematic in case of air-conditioning systems are the so-called air washers used for air humidification which can become an ideal cultur medium for microorganisms. A second problematic area are the often very dirty filters. But health risks can be avoided with regular expert maintenance alone. As first step an analysis of the causes of faults is proposed. (BWI)

  14. Phased mission modelling of systems with maintenance-free operating periods using simulated Petri nets

    Energy Technology Data Exchange (ETDEWEB)

    Chew, S.P.; Dunnett, S.J. [Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, Leics (United Kingdom); Andrews, J.D. [Department of Aeronautical and Automotive Engineering, Loughborough University, Loughborough, Leics (United Kingdom)], E-mail: j.d.andrews@lboro.ac.uk

    2008-07-15

    A common scenario in engineering is that of a system which operates throughout several sequential and distinct periods of time, during which the modes and consequences of failure differ from one another. This type of operation is known as a phased mission, and for the mission to be a success the system must successfully operate throughout all of the phases. Examples include a rocket launch and an aeroplane flight. Component or sub-system failures may occur at any time during the mission, yet not affect the system performance until the phase in which their condition is critical. This may mean that the transition from one phase to the next is a critical event that leads to phase and mission failure, with the root cause being a component failure in a previous phase. A series of phased missions with no maintenance may be considered as a maintenance-free operating period (MFOP). This paper describes the use of a Petri net (PN) to model the reliability of the MFOP and phased missions scenario. The model uses Monte-Carlo simulation to obtain its results, and due to the modelling power of PNs, can consider complexities such as component failure rate interdependencies and mission abandonment. The model operates three different types of PN which interact to provide the overall system reliability modelling. The model is demonstrated and validated by considering two simple examples that can be solved analytically.

  15. Phased mission modelling of systems with maintenance-free operating periods using simulated Petri nets

    International Nuclear Information System (INIS)

    Chew, S.P.; Dunnett, S.J.; Andrews, J.D.

    2008-01-01

    A common scenario in engineering is that of a system which operates throughout several sequential and distinct periods of time, during which the modes and consequences of failure differ from one another. This type of operation is known as a phased mission, and for the mission to be a success the system must successfully operate throughout all of the phases. Examples include a rocket launch and an aeroplane flight. Component or sub-system failures may occur at any time during the mission, yet not affect the system performance until the phase in which their condition is critical. This may mean that the transition from one phase to the next is a critical event that leads to phase and mission failure, with the root cause being a component failure in a previous phase. A series of phased missions with no maintenance may be considered as a maintenance-free operating period (MFOP). This paper describes the use of a Petri net (PN) to model the reliability of the MFOP and phased missions scenario. The model uses Monte-Carlo simulation to obtain its results, and due to the modelling power of PNs, can consider complexities such as component failure rate interdependencies and mission abandonment. The model operates three different types of PN which interact to provide the overall system reliability modelling. The model is demonstrated and validated by considering two simple examples that can be solved analytically

  16. EG-VEGF Maintenance Over Early Gestation to Develop a Pregnancy-Induced Hypertensive Animal Model.

    Science.gov (United States)

    Reynaud, Déborah; Sergent, Frédéric; Abi Nahed, Roland; Brouillet, Sophie; Benharouga, Mohamed; Alfaidy, Nadia

    2018-01-01

    During the last decade, multiple animal models have been developed to mimic hallmarks of pregnancy-induced hypertension (PIH) diseases, which include gestational hypertension, preeclampsia (PE), or eclampsia. Converging in vitro, ex vivo, and clinical studies from our group strongly suggested the potential involvement of the new angiogenic factor EG-VEGF (endocrine gland-derived-VEGF) in the development of PIH. Here, we described the protocol that served to demonstrate that maintenance of EG-VEGF production over 11.5 days post coitus (dpc) in the gravid mice caused the development of PIH. The developed model exhibited most hallmarks of preeclampsia.

  17. Providing Our Fellows in Training with Education on Inflammatory Bowel Disease Health Maintenance to Improve the Quality of Care in Our Health Care System.

    Science.gov (United States)

    Lee, Ann Joo; Kraemer, Dale F; Smotherman, Carmen; Eid, Emely

    2016-01-01

    Inflammatory bowel disease (IBD) quality measures were established in an effort to standardize IBD health care. Despite effort to improve clinical performance, considerable variations in practice still exist. To further improve IBD health care, we propose incorporating an in-service educational session on IBD health maintenance to provide trainees with increasing awareness and knowledge on IBD management. Fifty electronic medical charts were randomly selected, and the level of quality documentation was assessed for 15 core IBD quality measures. Data were reported as the percentage of charts meeting audit criteria (compliance score). Fellows then attended an in-service educational session to review IBD quality measures and reinforce practice expectations. A second audit was then performed on an additional 50 patient charts to determine whether documentation practices improved after the educational session. We found a positive correlation between an in-service educational session and fellows' compliance with IBD health maintenance. Overall, the fellows' compliance score increased by 18% (before intervention, 65%; after intervention, 83%; P bases for IBD health maintenance. Incorporating a standard curriculum on IBD health maintenance provides fellows in training with increased awareness and guidance on managing the unique preventive care needs of patients with IBD.

  18. A new modeling approach to the safety evaluation of N-modular redundant computer systems in presence of imperfect maintenance

    International Nuclear Information System (INIS)

    Flammini, Francesco; Marrone, Stefano; Mazzocca, Nicola; Vittorini, Valeria

    2009-01-01

    A large number of safety-critical control systems are based on N-modular redundant architectures, using majority voters on the outputs of independent computation units. In order to assess the compliance of these architectures with international safety standards, the frequency of hazardous failures must be analyzed by developing and solving proper formal models. Furthermore, the impact of maintenance faults has to be considered, since imperfect maintenance may degrade the safety integrity level of the system. In this paper, we present both a failure model for voting architectures based on Bayesian networks and a maintenance model based on continuous time Markov chains, and we propose to combine them according to a compositional multiformalism modeling approach in order to analyze the impact of imperfect maintenance on the system safety. We also show how the proposed approach promotes the reuse and the interchange of models as well the interchange of solving tools.

  19. Procedure to evaluate and control efficiently the operations management of medical equipment in the maintenance unit of a health institution

    Directory of Open Access Journals (Sweden)

    Herrera-Galán Michael

    2018-01-01

    Full Text Available Maintenance management plays a very important role in the success of any company. As a consequence of this, in the year of 2013, a study was carried out in health facilities found in the South Eastern Region of Jamaica with the objective of evaluating the existing Maintenance Management Program for Medical Equipment. Among the results obtained, it showed that there is an inadequacy in the existing program whose principal deficiency is attributed to the operations management. As such, this work proposes a procedure for evaluating and controlling in an efficient manner the operations management within the Biomedical Department which forms part of the South East Regional Health Authority Maintenance Unit (SERHAMU, this latter is found on the premises of the Bustamante Hospital for Children (BHC, Jamaica. The method used to develop the procedure (GOMHO is based fundamentally on the design of: a codification system to identify control registers and to record failures associated with each equipment, a system of placing equipment into categories and further differentiating them based on the potential hazard such pose on the human body in the event of an operational failure. In addition, this procedure gives the SERHAMU at the BHC the opportunity to calculate the amount of human resources needed to carry out efficiently the preventative and corrective maintenance work being demanded on the department. During the implementation phase, the results demonstrated that from the control procedure designed there was an improvement in the planning and carrying out of maintenance work and a better system of monitoring the activities that are executed. Also, it was evidenced that there is a 61.53% of the amount of human resources needed to carry out the maintenance actions.

  20. A review of a priori regression models for warfarin maintenance dose prediction.

    Directory of Open Access Journals (Sweden)

    Ben Francis

    Full Text Available A number of a priori warfarin dosing algorithms, derived using linear regression methods, have been proposed. Although these dosing algorithms may have been validated using patients derived from the same centre, rarely have they been validated using a patient cohort recruited from another centre. In order to undertake external validation, two cohorts were utilised. One cohort formed by patients from a prospective trial and the second formed by patients in the control arm of the EU-PACT trial. Of these, 641 patients were identified as having attained stable dosing and formed the dataset used for validation. Predicted maintenance doses from six criterion fulfilling regression models were then compared to individual patient stable warfarin dose. Predictive ability was assessed with reference to several statistics including the R-square and mean absolute error. The six regression models explained different amounts of variability in the stable maintenance warfarin dose requirements of the patients in the two validation cohorts; adjusted R-squared values ranged from 24.2% to 68.6%. An overview of the summary statistics demonstrated that no one dosing algorithm could be considered optimal. The larger validation cohort from the prospective trial produced more consistent statistics across the six dosing algorithms. The study found that all the regression models performed worse in the validation cohort when compared to the derivation cohort. Further, there was little difference between regression models that contained pharmacogenetic coefficients and algorithms containing just non-pharmacogenetic coefficients. The inconsistency of results between the validation cohorts suggests that unaccounted population specific factors cause variability in dosing algorithm performance. Better methods for dosing that take into account inter- and intra-individual variability, at the initiation and maintenance phases of warfarin treatment, are needed.

  1. A review of a priori regression models for warfarin maintenance dose prediction.

    Science.gov (United States)

    Francis, Ben; Lane, Steven; Pirmohamed, Munir; Jorgensen, Andrea

    2014-01-01

    A number of a priori warfarin dosing algorithms, derived using linear regression methods, have been proposed. Although these dosing algorithms may have been validated using patients derived from the same centre, rarely have they been validated using a patient cohort recruited from another centre. In order to undertake external validation, two cohorts were utilised. One cohort formed by patients from a prospective trial and the second formed by patients in the control arm of the EU-PACT trial. Of these, 641 patients were identified as having attained stable dosing and formed the dataset used for validation. Predicted maintenance doses from six criterion fulfilling regression models were then compared to individual patient stable warfarin dose. Predictive ability was assessed with reference to several statistics including the R-square and mean absolute error. The six regression models explained different amounts of variability in the stable maintenance warfarin dose requirements of the patients in the two validation cohorts; adjusted R-squared values ranged from 24.2% to 68.6%. An overview of the summary statistics demonstrated that no one dosing algorithm could be considered optimal. The larger validation cohort from the prospective trial produced more consistent statistics across the six dosing algorithms. The study found that all the regression models performed worse in the validation cohort when compared to the derivation cohort. Further, there was little difference between regression models that contained pharmacogenetic coefficients and algorithms containing just non-pharmacogenetic coefficients. The inconsistency of results between the validation cohorts suggests that unaccounted population specific factors cause variability in dosing algorithm performance. Better methods for dosing that take into account inter- and intra-individual variability, at the initiation and maintenance phases of warfarin treatment, are needed.

  2. 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.

  3. Genome-health nutrigenomics and nutrigenetics: nutritional requirements or 'nutriomes' for chromosomal stability and telomere maintenance at the individual level.

    Science.gov (United States)

    Bull, Caroline; Fenech, Michael

    2008-05-01

    It is becoming increasingly evident that (a) risk for developmental and degenerative disease increases with more DNA damage, which in turn is dependent on nutritional status, and (b) the optimal concentration of micronutrients for prevention of genome damage is also dependent on genetic polymorphisms that alter the function of genes involved directly or indirectly in the uptake and metabolism of micronutrients required for DNA repair and DNA replication. The development of dietary patterns, functional foods and supplements that are designed to improve genome-health maintenance in individuals with specific genetic backgrounds may provide an important contribution to an optimum health strategy based on the diagnosis and individualised nutritional prevention of genome damage, i.e. genome health clinics. The present review summarises some of the recent knowledge relating to micronutrients that are associated with chromosomal stability and provides some initial insights into the likely nutritional factors that may be expected to have an impact on the maintenance of telomeres. It is evident that developing effective strategies for defining nutrient doses and combinations or 'nutriomes' for genome-health maintenance at the individual level is essential for further progress in this research field.

  4. Nurse bullying: organizational considerations in the maintenance and perpetration of health care bullying cultures.

    Science.gov (United States)

    Lewis, Malcolm A

    2006-01-01

    To examine bullying within nursing from a micro-sociological perspective and elucidate interactive mechanisms contributing to its causes and continuation within the nursing profession. The paper is part of a doctoral research study into bullying within nursing. It considers issues pertinent to management, and in the role of negotiated interactions within the National Health Service when dealing with bullying problems. The complex dynamics involved can be problematic for management when dealing with bullying, while often managers have been targets of bullying themselves and not infrequently accused of it. Features of bullying activity are explored, along with issues of target and bully awareness, a central feature in bullying negotiations. Issues of awareness and emergence of bullying behaviour have been identified through vignettes and unstructured interviews, and the research has identified complex interactive events in the creation and maintenance of nurse bullying activity. It is hoped that with a clearer understanding of such mechanisms and manifestations that bullying in the workplace can be reduced or eliminated. The paper is of practical use to nurse managers in illuminating such mechanisms and bringing bullying awareness to the fore. Such activity is ultimately damaging to the organization in both cost and time; and significant for professional practice by its impact upon the nurse and their work in supportive and safe environments. It will also to allow managers to consider their own practice and reactions to bullying activity within the profession. The overall findings from the research point strongly to bullying activity being essentially 'learned behaviour' within the workplace rather than any predominantly psychological deficit within individual perpetrators and targets.

  5. Development of a Wireless Unified-Maintenance System for the Structural Health Monitoring of Civil Structures.

    Science.gov (United States)

    Heo, Gwanghee; Son, Byungjik; Kim, Chunggil; Jeon, Seunggon; Jeon, Joonryong

    2018-05-09

    A disaster preventive structural health monitoring (SHM) system needs to be equipped with the following abilities: First, it should be able to simultaneously measure diverse types of data (e.g., displacement, velocity, acceleration, strain, load, temperature, humidity, etc.) for accurate diagnosis. Second, it also requires standalone power supply to guarantee its immediate response in crisis (e.g., sudden interruption of normal AC power in disaster situations). Furthermore, it should be capable of prompt processing and realtime wireless communication of a huge amount of data. Therefore, this study is aimed at developing a wireless unified-maintenance system (WUMS) that would satisfy all the requirements for a disaster preventive SHM system of civil structures. The WUMS is designed to measure diverse types of structural responses in realtime based on wireless communication, allowing users to selectively use WiFi RF band and finally working in standalone mode by means of the field-programmable gate array (FPGA) technology. To verify its performance, the following tests were performed: (i) A test to see how far communication is possible in open field, (ii) a test on a shaker to see how accurate responses are, (iii) a modal test on a bridge to see how exactly characteristic real-time dynamic responses are of structures. The test results proved that the WUMS was able to secure stable communication far up to nearly 800 m away by acquiring wireless responses in realtime accurately, when compared to the displacement and acceleration responses which were acquired through wired communication. The analysis of dynamic characteristics also showed that the wireless acceleration responses in real-time represented satisfactorily the dynamic properties of structures. Therefore, the WUMS is proved valid as a SHM, and its outstanding performance is also proven.

  6. Control software architecture and operating modes of the Model M-2 maintenance system

    Energy Technology Data Exchange (ETDEWEB)

    Satterlee, P.E. Jr.; Martin, H.L.; Herndon, J.N.

    1984-04-01

    The Model M-2 maintenance system is the first completely digitally controlled servomanipulator. The M-2 system allows dexterous operations to be performed remotely using bilateral force-reflecting master/slave techniques, and its integrated operator interface takes advantage of touch-screen-driven menus to allow selection of all possible operating modes. The control system hardware for this system has been described previously. This paper describes the architecture of the overall control system. The system's various modes of operation are identified, the software implementation of each is described, system diagnostic routines are described, and highlights of the computer-augmented operator interface are discussed. 3 references, 5 figures.

  7. Control software architecture and operating modes of the Model M-2 maintenance system

    International Nuclear Information System (INIS)

    Satterlee, P.E. Jr.; Martin, H.L.; Herndon, J.N.

    1984-04-01

    The Model M-2 maintenance system is the first completely digitally controlled servomanipulator. The M-2 system allows dexterous operations to be performed remotely using bilateral force-reflecting master/slave techniques, and its integrated operator interface takes advantage of touch-screen-driven menus to allow selection of all possible operating modes. The control system hardware for this system has been described previously. This paper describes the architecture of the overall control system. The system's various modes of operation are identified, the software implementation of each is described, system diagnostic routines are described, and highlights of the computer-augmented operator interface are discussed. 3 references, 5 figures

  8. A holistic framework of degradation modeling for reliability analysis and maintenance optimization of nuclear safety systems

    International Nuclear Information System (INIS)

    Lin, Yanhui

    2016-01-01

    Components of nuclear safety systems are in general highly reliable, which leads to a difficulty in modeling their degradation and failure behaviors due to the limited amount of data available. Besides, the complexity of such modeling task is increased by the fact that these systems are often subject to multiple competing degradation processes and that these can be dependent under certain circumstances, and influenced by a number of external factors (e.g. temperature, stress, mechanical shocks, etc.). In this complicated problem setting, this PhD work aims to develop a holistic framework of models and computational methods for the reliability-based analysis and maintenance optimization of nuclear safety systems taking into account the available knowledge on the systems, degradation and failure behaviors, their dependencies, the external influencing factors and the associated uncertainties.The original scientific contributions of the work are: (1) For single components, we integrate random shocks into multi-state physics models for component reliability analysis, considering general dependencies between the degradation and two types of random shocks. (2) For multi-component systems (with a limited number of components):(a) a piecewise-deterministic Markov process modeling framework is developed to treat degradation dependency in a system whose degradation processes are modeled by physics-based models and multi-state models; (b) epistemic uncertainty due to incomplete or imprecise knowledge is considered and a finite-volume scheme is extended to assess the (fuzzy) system reliability; (c) the mean absolute deviation importance measures are extended for components with multiple dependent competing degradation processes and subject to maintenance; (d) the optimal maintenance policy considering epistemic uncertainty and degradation dependency is derived by combining finite-volume scheme, differential evolution and non-dominated sorting differential evolution; (e) the

  9. Safety constraints applied to an adaptive Bayesian condition-based maintenance optimization model

    International Nuclear Information System (INIS)

    Flage, Roger; Coit, David W.; Luxhøj, James T.; Aven, Terje

    2012-01-01

    A model is described that determines an optimal inspection and maintenance scheme for a deteriorating unit with a stochastic degradation process with independent and stationary increments and for which the parameters are uncertain. This model and resulting maintenance plans offers some distinct benefits compared to prior research because the uncertainty of the degradation process is accommodated by a Bayesian approach and two new safety constraints have been applied to the problem: (1) with a given subjective probability (degree of belief), the limiting relative frequency of one or more failures during a fixed time interval is bounded; or (2) the subjective probability of one or more failures during a fixed time interval is bounded. In the model, the parameter(s) of a condition-based inspection scheduling function and a preventive replacement threshold are jointly optimized upon each replacement and inspection such as to minimize the expected long run cost per unit of time, but also considering one of the specified safety constraints. A numerical example is included to illustrate the effect of imposing each of the two different safety constraints.

  10. Organisation of maintenance of health semi-portable detectors. IPAB-CFA-CABP control bench; Organisation de la maintenance des detecteurs semi-portatifs de sante. Banc de controle des IPAB-CFA-CABP

    Energy Technology Data Exchange (ETDEWEB)

    De Choudens, H.; Rage, P. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Grenoble (France)

    1963-07-01

    As the number of electronic semi-portable health measurement devices is (was) increasing, it appears (appeared) important to organise their maintenance. In this report, the authors describe the implemented organisation. They indicate how a device is identified, which are the performed tests, and discuss results which have been obtained during the first year of implementation of this maintenance organisation. Then, they present the control bench, its operation (supply, measurement circuits), its use (control process for different devices, performed measurements and controls)

  11. Organizational Culture Influence On Total Productive Maintenance (TPM and Operational Performance Using RASCH Model Analysis

    Directory of Open Access Journals (Sweden)

    Mohd Norhasni Mohd Asaad

    2014-02-01

    Full Text Available Abstract. Market globalization, competitive product and services, high economic crises are the most critical factors that influence the success of the manufacturing companies in global market. Therefore it is critical to the manufacturing companies to be efficient in production and lean tool may used to achieve that.  The most frequently used is the Total Preventive Maintenance (TPM, even though there are many studies have been conducted in relation to the TPM but there is limited research in investigating the effects of the TPM on operational performance. However, the result of the studies was not consistent, where TPM practice may have positive and negative impact on operational performance. Among the reason is the culture of the organization that influenced the implementation of TPM and operational performance. Due to that this study attempts to investigate the influence of organizational culture on the TPM implementation and operational performance.  Rasch model is used in this study due to its ability in interpreting and analyzing the ability of respondents in performing the difficult items. The online questionnaires were distributed to 63 randomly selected automotive companies located at Northern Region of Malaysia.  Results of the study revealed that the organizational culture has influenced on the successful implementation of TPM and operational performance. Therefore by the implementation of TPM in outstanding organizational culture can improve operational performance.   Keyword: Total Preventive Maintenance (TPM, Lean manufacturing, Operational performance, Organizational culture, Rasch modeldoi:10.12695/ajtm.2013.6.2.2How to cite this article:Mohd Asaad, M.N and Yusoff, R.Z. (2013. Organizational Culture Influence On Total Productive Maintenance (TPM and Operational Performance Using RASCH Model Analysis . The Asian Journal of Technology Management 6 (2: 72-81. Print ISSN: 1978-6956; Online ISSN: 2089-791X.  doi:10.12695/ajtm

  12. Maintenance service contract model for heavy equipment in mining industry using principal agent theory

    Science.gov (United States)

    Pakpahan, Eka K. A.; Iskandar, Bermawi P.

    2015-12-01

    Mining industry is characterized by a high operational revenue, and hence high availability of heavy equipment used in mining industry is a critical factor to ensure the revenue target. To maintain high avaliability of the heavy equipment, the equipment's owner hires an agent to perform maintenance action. Contract is then used to control the relationship between the two parties involved. The traditional contracts such as fixed price, cost plus or penalty based contract studied is unable to push agent's performance to exceed target, and this in turn would lead to a sub-optimal result (revenue). This research deals with designing maintenance contract compensation schemes. The scheme should induce agent to select the highest possible maintenance effort level, thereby pushing agent's performance and achieve maximum utility for both parties involved. Principal agent theory is used as a modeling approach due to its ability to simultaneously modeled owner and agent decision making process. Compensation schemes considered in this research includes fixed price, cost sharing and revenue sharing. The optimal decision is obtained using a numerical method. The results show that if both parties are risk neutral, then there are infinite combination of fixed price, cost sharing and revenue sharing produced the same optimal solution. The combination of fixed price and cost sharing contract results in the optimal solution when the agent is risk averse, while the optimal combination of fixed price and revenue sharing contract is obtained when agent is risk averse. When both parties are risk averse, the optimal compensation scheme is a combination of fixed price, cost sharing and revenue sharing.

  13. Towards a new model of attentional biases in the development, maintenance, and management of pain.

    Science.gov (United States)

    Todd, Jemma; Sharpe, Louise; Johnson, Ameika; Nicholson Perry, Kathryn; Colagiuri, Ben; Dear, Blake F

    2015-09-01

    Individuals with chronic pain demonstrate attentional biases (ABs) towards pain-related stimuli. However, the clinical importance of these biases is yet to be determined and a sound theoretical model for explaining the role of ABs in the development and maintenance of pain is lacking. Within this article, we (1) systematically review prospective and experimental research exploring ABs and pain outcomes in light of current theoretical models and (2) propose a theoretical framework for understanding AB in pain. Across prospective research, an attentional pattern of vigilance-avoidance was observed. Interventions targeting ABs were less consistent; however, there were promising findings among studies that found attentional training effects, particularly for laboratory research. The proposed Threat Interpretation Model suggests a relationship between threat, interpretation, and stimuli in determining attentional processes, which while tentative generates important testable predictions regarding the role of attention in pain and builds on previous theoretical and empirical work in this area.

  14. Optimization of condition-based asset management using a predictive health model

    NARCIS (Netherlands)

    Bajracharya, G.; Koltunowicz, T.; Negenborn, R.R.; Papp, Z.; Djairam, D.; De Schutter, B.; Smit, J.J.

    2009-01-01

    In this paper, a model predictive framework is used to optimize the operation and maintenance actions of power system equipment based on the predicted health sate of this equipment. In particular, this framework is used to predict the health state of transformers based on their usage. The health

  15. Maintenance of algal endosymbionts in Paramecium bursaria: a simple model based on population dynamics.

    Science.gov (United States)

    Iwai, Sosuke; Fujiwara, Kenji; Tamura, Takuro

    2016-09-01

    Algal endosymbiosis is widely distributed in eukaryotes including many protists and metazoans, and plays important roles in aquatic ecosystems, combining phagotrophy and phototrophy. To maintain a stable symbiotic relationship, endosymbiont population size in the host must be properly regulated and maintained at a constant level; however, the mechanisms underlying the maintenance of algal endosymbionts are still largely unknown. Here we investigate the population dynamics of the unicellular ciliate Paramecium bursaria and its Chlorella-like algal endosymbiont under various experimental conditions in a simple culture system. Our results suggest that endosymbiont population size in P. bursaria was not regulated by active processes such as cell division coupling between the two organisms, or partitioning of the endosymbionts at host cell division. Regardless, endosymbiont population size was eventually adjusted to a nearly constant level once cells were grown with light and nutrients. To explain this apparent regulation of population size, we propose a simple mechanism based on the different growth properties (specifically the nutrient requirements) of the two organisms, and based from this develop a mathematical model to describe the population dynamics of host and endosymbiont. The proposed mechanism and model may provide a basis for understanding the maintenance of algal endosymbionts. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Asset Management Business Model for Design, Realization, and Maintenance of Fibre Reinforced Polymer Bridges

    Directory of Open Access Journals (Sweden)

    Rizal Sebastian

    2013-01-01

    Full Text Available This paper particularly addresses the market implementation of Fibre Reinforced Polymer (FRP for bridges. It presents the concept of demand and supply chain innovation as being investigated within two ongoing European collaborative research projects (FP7 titled Trans-IND and PANTURA. FRP has emerged as a real alternative structural material based on various sustainability considerations, among others the reduced life-cycle cost due to less maintenance needs, longer lifetime, and easiness to repair, replace, or recycle the components. The Trans-IND research project aims to develop and demonstrate new industrialized processes to use FRP for civil infrastructure projects at a large scale. In order to be cost effective, a new value-chain strategy for the design, realization, and maintenance of FRP bridges is required to replace the fragmented supply chain and the one-off approach to a construction project. This paper focuses on the development of new business models based on asset management strategy, which covers the entire demand and supply chains. Research on new business models is supported by the insight into the market and regulatory frameworks in different EU countries. This is based on field surveys across the EU that have been carried out as a part of the Trans-IND and PANTURA collaborative research projects.

  17. Low-complexity Behavioral Model for Predictive Maintenance of Railway Turnouts

    DEFF Research Database (Denmark)

    Barkhordari, Pegah; Galeazzi, Roberto; Tejada, Alejandro de Miguel

    2017-01-01

    Maintenance of railway infrastructures represents a major cost driver for any infrastructure manager since reliability and dependability must be guaranteed at all times. Implementation of predictive maintenance policies relies on the availability of condition monitoring systems able to assess...

  18. Beyond AIRSpeed: How Organizational Modeling and Simulation Further Reduced Engine Maintenance Time

    National Research Council Canada - National Science Library

    Hagan, Joel; Slack, William; Zolin, Roxanne; Dillard, John

    2007-01-01

    The Aircraft Intermediate Maintenance Division (AIMD) at Naval Air Station (NAS) Lemoore, CA, has worked aggressively to reduce engine maintenance time using the tools of the NAVAIR Enterprise AiRSpeed (AiRSpeed) program...

  19. An investigation of an open-access model for scaling up methadone maintenance treatment.

    Science.gov (United States)

    Madden, Lynn M; Farnum, Scott O; Eggert, Kathryn F; Quanbeck, Andrew R; Freeman, Robert M; Ball, Samuel A; Schottenfeld, Richard S; Shi, Julia M; Savage, Mary Ellen; Barry, Declan T

    2018-02-17

    To examine retrospectively patient and programmatic outcomes following the development and implementation of an 'open-access' model in which prospective patients were enrolled rapidly in methadone maintenance treatment, irrespective of ability to pay, and provided real-time access to multiple voluntary treatment options. Medical and administrative records were abstracted to compare data for 1 year before and 9 years after initiating the implementation of an open-access treatment model in May 2007. Methadone maintenance treatment center in Connecticut, USA. Individuals with opioid use disorder entering treatment between July 2006 and June 2015. In June 2015, 64% (n = 2594) of the sample were men and 80% (n = 3133) reported that they were white. The Network for the Improvement of Addiction Treatment-informed open-access treatment model uses process improvement strategies to improve treatment access and capacity. Census, waiting time, retention, non-medical opioid use, patient mortality and financial sustainability (net income and state-block grants as proportions of revenue). In the 9 years following the initial implementation of the open-access model, patient census increased by 183% from 1431 to 4051, and average waiting-time days decreased from 21 to 0.3 (same day) without apparent deleterious effects on rates of retention, non-medical opioid use or mortality. Between fiscal years (FY) 06 and FY 15, net operating margin rose from 2 to 10%, while state-block grant revenues declined 14% and the proportion of total revenue from state-block grant revenue decreased from 49 to 24%. An open-access model for rapid enrolment of people with opioid use disorder in methadone treatment appears to improve treatment access, capacity, and financial sustainability without evidence of deleterious effects on treatment outcomes. © 2018 Society for the Study of Addiction.

  20. Predictive modeling for corrective maintenance of imaging devices from machine logs.

    Science.gov (United States)

    Patil, Ravindra B; Patil, Meru A; Ravi, Vidya; Naik, Sarif

    2017-07-01

    In the cost sensitive healthcare industry, an unplanned downtime of diagnostic and therapy imaging devices can be a burden on the financials of both the hospitals as well as the original equipment manufacturers (OEMs). In the current era of connectivity, it is easier to get these devices connected to a standard monitoring station. Once the system is connected, OEMs can monitor the health of these devices remotely and take corrective actions by providing preventive maintenance thereby avoiding major unplanned downtime. In this article, we present an overall methodology of predicting failure of these devices well before customer experiences it. We use data-driven approach based on machine learning to predict failures in turn resulting in reduced machine downtime, improved customer satisfaction and cost savings for the OEMs. One of the use-case of predicting component failure of PHILIPS iXR system is explained in this article.

  1. Religious leaders' opinions and guidance towards oral health maintenance and promotion: a qualitative study.

    Science.gov (United States)

    Zini, Avraham; Sgan-Cohen, Harold D; Feder-Bubis, Paula

    2015-04-01

    Religions emphasize the supreme value of life. However, potential or concrete conflicts of perception between dictates of faith and science often present an inescapable dilemma. The aim of this qualitative research was to examine the views of spiritual and religious leaders towards general and oral health issues. A total of 11 eminent Jewish spiritual and religious community leaders were purposively chosen. They were interviewed using a semi-structured questionnaire. The verbatim transcriptions of the interviews were analysed in the spirit of grounded theory, using qualitative data analysis software. Open, axial, and thematic coding served to build categories and themes. Analysis of participants' perspectives reflected that they, based upon Jewish theology, attributed high importance to primary prevention at both personal and community levels. Religious and orthodox people were depicted as being motivated towards maintaining oral health behaviours due to a sense of obligation to follow religious edicts, strong social support, and elevated perceived spiritual levels. We offer a theoretical model that can explain the potential high motivation among these communities towards implementing positive general and oral health behaviours. Religiosity may be regarded as an example of a psycho-social health determinant, encompassing spiritual belief ("psycho") and social support ("social") components.

  2. Modeling the impact of thermal effects on luminous flux maintenance for SSL luminaires

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Lynn [RTI International, Research Triangle Park, NC (United States); Mills, Karmann [RTI International, Research Triangle Park, NC (United States); Lamvik, Michael [RTI International, Research Triangle Park, NC (United States); Solano, Eric [RTI International, Research Triangle Park, NC (United States); Bobashev, Georgiy [RTI International, Research Triangle Park, NC (United States); Perkins, Curtis [RTI International, Research Triangle Park, NC (United States)

    2017-05-30

    Meeting the longevity requirements of solid-state lighting (SSL) devices places extreme demands on the materials and designs that are used in SSL luminaires. Therefore, understanding the aging characteristics of lens, reflectors, and other materials is essential to projecting the long-term performance of LED-based lighting systems. Overlooking these factors at either the design or product specification stage can result in premature failure of the device due to poor luminous flux maintenance and/or excessive chromaticity shifts. This paper describes a methodology for performing accelerated stress testing (AST) on materials intended for use in SSL luminaires. This test methodology, which consists of elevated temperature and humidity conditions, produces accelerated aging data that can be correlated to expected performance under normal luminaire operating conditions. The correlations can then be leveraged to produce models of the changes in the optical properties of key materials including transmittance versus wavelength of lenses and reflectance versus wavelength for housings and other reflectors. This information has been collected into a lumen maintenance decision support tool (LM-DST) and together with user supplied inputs (e.g., expected operation conditions) can provide guidance on lifetime expectations of SSL luminaires. This approach has been applied to a variety of materials commonly found in SSL luminaires including acrylics, polycarbonates, and silicones used for lenses and paints, coatings, films, and composites used for reflectors.

  3. JAVANESE CULTURAL WORDS IN LOCAL NEWSPAPERS IN CENTRAL JAVA AS A LANGUAGE MAINTENANCE MODEL

    Directory of Open Access Journals (Sweden)

    Deli Nirmala

    2016-04-01

    Full Text Available Javanese cultural words are the linguistic units which are very specific to Javanese culture and society. This article aims at describing what Javanese cultural words that are found in the local newspapers, what they represent, and why they are used in the local newspapers in Central Java. Non-participant observation is used to present the data for analysis, continued with page-filing and note-taking techniques. Referential, reflective-introspective, and abductive inferential methods are used to analyze the data. The result indicates that the Javanese cultural words found in the local newspapers represent festivals, rituals, Javanese ways of life, social activities, actions, feelings, thoughts, behavior, and experiences. The words become the indicators that the journalists of the local newspapers in Cental Java have positive attitudes toward Javanese words. This becomes a model for language maintenance of Javanese. This implies that the words are stored in the long-term memory, that become mental image, which are used when needed by the user for communication. The existence of the concepts residing in the mind will make the Javanese language maintenance possible, which is supported by the attitudes of the Javanese.

  4. Executive function in weight loss and weight loss maintenance: a conceptual review and novel neuropsychological model of weight control.

    Science.gov (United States)

    Gettens, Katelyn M; Gorin, Amy A

    2017-10-01

    Weight loss maintenance is a complex, multifaceted process that presents a significant challenge for most individuals who lose weight. A growing body of literature indicates a strong relationship between cognitive dysfunction and excessive body weight, and suggests that a subset of high-order cognitive processes known as executive functions (EF) likely play an important role in weight management. Recent reviews cover neuropsychological correlates of weight status yet fail to address the role of executive function in the central dilemma of successful weight loss maintenance. In this paper, we provide an overview of the existing literature examining executive functions as they relate to weight status and initial weight loss. Further, we propose a novel conceptual model of the relationships between EF, initial weight loss, and weight loss maintenance, mapping specific executive functions onto strategies known to be associated with both phases of the weight control process. Implications for the development of more efficacious weight loss maintenance interventions are discussed.

  5. Relating the construction and maintenance of maternal ill-health in rural Indonesia

    Directory of Open Access Journals (Sweden)

    Lucia D'Ambruoso

    2012-08-01

    Full Text Available Estimates suggest that over 350,000 deaths and more than 20 million severe disabilities result from the complications of pregnancy, childbirth or its management each year. Death and disability occur predominately among disadvantaged women in resource-poor settings and are largely preventable with adequate delivery care. This paper presents the substantive findings and policy implications from a programme of PhD research, of which the overarching objective was to assess quality of, and access to, care in obstetric emergencies. Three critical incident audits were conducted in two rural districts on Java, Indonesia: a confidential enquiry, a verbal autopsy survey, and a community-based review. The studies examined cases of maternal mortality and severe morbidity from the perspectives of local service users and health providers. A range of inter-related determining factors was identified. When unexpected delivery complications occurred, women and families were often uninformed, unprepared, found care unavailable, unaffordable, and many relied on traditional providers. Midwives in villages made important contributions by stabilising women and facilitating referrals but were often scarce in remote areas and lacked sufficient clinical competencies and payment incentives to treat the poor. Emergency transport was often unavailable and private transport was unreliable and incurred costs. In facilities, there was a reluctance to admit poorer women and those accepted were often admitted to ill-equipped, under-staffed wards. As a result, referrals between hospitals were also common. Otherwise, social health insurance, designed to reduce financial barriers, was particularly problematic, constraining quality and access within and outside facilities. Health workers and service users provided rich and explicit assessments of care and outcomes. These were used to develop a conceptual model in which quality and access are conceived of as social processes

  6. Tenacious self-reliance in health maintenance may jeopardize late life survival.

    Science.gov (United States)

    Hamm, Jeremy M; Chipperfield, Judith G; Perry, Raymond P; Parker, Patti C; Heckhausen, Jutta

    2017-11-01

    Although an active pursuit of health goals is typically adaptive, there may be circumstances in very late life when it is not. Our 10-year study of community-dwelling individuals (n = 220, 79-98 years-old) examined whether investing substantial effort into personal health (high selective primary control) in the absence of help-seeking strategies (low compensatory primary control) jeopardized survival for very old adults who varied in functional independence (low, high). Cox proportional hazard models showed selective primary control (SPC) predicted 10-year mortality risk for only those with low compensatory primary control (CPC) and high initial functional independence. For these individuals, each standard deviation increase in SPC predicted a 101% higher risk of death. Results are consistent with the lines-of-defense model (Heckhausen et al., 2013) and suggest that, for very old adults with little previous need for help-seeking strategies, tenacious self-reliance (high SPC, low CPC) may have life-shortening consequences. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Communication models in environmental health.

    Science.gov (United States)

    Guidotti, Tee L

    2013-01-01

    Communication models common in environmental health are not well represented in the literature on health communication. Risk communication is a systematic approach to conveying essential information about a specific environmental issue and a framework for thinking about community risk and the alternatives for dealing with it. Crisis communication is intended to provide essential information to people facing an emergency in order to mitigate its effects and to enable them to make appropriate decisions, and it is primarily used in emergency management. Corporate communication is intended to achieve a change in attitude or perception of an organization, and its role in environmental health is usually public relations or to rehabilitate a damaged reputation. Environmental health education is a more didactic approach to science education with respect to health and the environment. Social marketing uses conventional marketing methods to achieve a socially desirable purpose but is more heavily used in health promotion generally. Communication models and styles in environmental health are specialized to serve the needs of the field in communicating with the community. They are highly structured and executed in different ways but have in common a relative lack of emphasis on changing personal or lifestyle behavior compared with health promotion and public health in general and a tendency to emphasize content on specific environmental issues and decision frameworks for protecting oneself or the community through collective action.

  8. Clinical pharmacy cardiac risk service for managing patients with coronary artery disease in a health maintenance organization.

    Science.gov (United States)

    Sandhoff, Brian G; Nies, Leslie K; Olson, Kari L; Nash, James D; Rasmussen, Jon R; Merenich, John A

    2007-01-01

    A clinical pharmacy service for managing the treatment of coronary artery disease in a health maintenance organization is described. Despite the proven benefits of aggressive risk factor modification for patients with coronary artery disease (CAD), there remains a treatment gap between consensus- and evidence-based recommendations and their application in patient care. In 1998, Kaiser Permanente of Colorado developed the Clinical Pharmacy Cardiac Risk Service (CPCRS) to focus on the long-term management of patients with CAD to improve clinical outcomes. The primary goals of the CPCRS are to increase the number of CAD patients on lipid-lowering therapy, manage medications shown to decrease the risk of future CAD-related events, assist in the monitoring and control of other diseases that increase cardiovascular risk, provide patient education and recommendations for nonpharmacologic therapy, and act as a CAD information resource for physicians and other health care providers. Using an electronic medical record and tracking database, the service works in close collaboration with primary care physicians, cardiologists, cardiac rehabilitation nurses, and other health care providers to reduce cardiac risk in the CAD population. Particular attention is given to dyslipidemia, blood pressure, diabetes mellitus, and tobacco cessation. Treatment with evidence-based regimens is initiated and adjusted as necessary. Over 11,000 patients are currently being followed by the CPCRS. A clinical pharmacy service in a large health maintenance organization provides cardiac risk reduction for patients with CAD and helps close treatment gaps that may exist for these patients.

  9. Health disparities, politics, and the maintenance of the status quo: A new theory of inequality.

    Science.gov (United States)

    Rodriguez, Javier M

    2018-03-01

    Individuals participate in politics to influence the politicians that prescribe the policies and programs that distribute the public goods and services that shape the social determinants of health. But the opportunity to participate in politics is conditional on survival, and in the U.S., the haves enjoy a significant survival advantage over the have-nots. This process can be detected looking at the relationship between age and participation: It is inflated by the fact that, as time progresses, a higher proportion of low-SES, low-level participation individuals die and are therefore excluded from the available pool of participants faster than high-SES, high-level participation individuals. We analyze this mechanism applying propensity scores matching and multivariate regressions on data from MIDUS I (Midlife in the United States: A National Study of Health and Well-being) and its 10-year mortality follow-up. Results show that health differences between 10-year survivors and non-survivors explain 56% of their differences in socio-political participation. Survivors participate at higher levels than non-survivors across all age groups and SES levels; without detrimental differences in health, individuals would participate 28% more as they age. The same disadvantaged individuals whose increased participation would pressure for redistributive policies are those who die off from the available pool of participants at much higher rates than socioeconomically advantaged individuals. The proposed conceptual model helps to explain how, through the early disappearance of the poor, continuing socio-political participation of high-SES survivors helps to perpetuate inequality in the status quo. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Health insurance basic actuarial models

    CERN Document Server

    Pitacco, Ermanno

    2014-01-01

    Health Insurance aims at filling a gap in actuarial literature, attempting to solve the frequent misunderstanding in regards to both the purpose and the contents of health insurance products (and ‘protection products’, more generally) on the one hand, and the relevant actuarial structures on the other. In order to cover the basic principles regarding health insurance techniques, the first few chapters in this book are mainly devoted to the need for health insurance and a description of insurance products in this area (sickness insurance, accident insurance, critical illness covers, income protection, long-term care insurance, health-related benefits as riders to life insurance policies). An introduction to general actuarial and risk-management issues follows. Basic actuarial models are presented for sickness insurance and income protection (i.e. disability annuities). Several numerical examples help the reader understand the main features of pricing and reserving in the health insurance area. A short int...

  11. Prediction of L70 lumen maintenance and chromaticity for LEDs using extended Kalman filter models

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep; Wei, Junchao; Davis, Lynn

    2013-09-30

    Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. The measured state variable has been related to the underlying damage using physics-based models. Life

  12. [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.

  13. A durability model incorporating safe life methodology and damage tolerance approach to assess first inspection and maintenance period for structures

    International Nuclear Information System (INIS)

    Xiong, J.J.; Shenoi, R.A.

    2009-01-01

    This paper outlines a new durability model to assess the first inspection and maintenance period for structures. Practical scatter factor formulae are presented to determine the safe fatigue crack initiation and propagation lives from the results of a single full-scale test of a complete structure. New theoretical solutions are proposed to determine the s a -s m -N surfaces of fatigue crack initiation and propagation. Prediction techniques are then developed to establish the relationship equation between safe fatigue crack initiation and propagation lives with a specific reliability level using a two-stage fatigue damage cumulative rule. A new durability model incorporating safe life and damage tolerance design approaches is derived to assess the first inspection and maintenance period. Finally, the proposed models are applied to assess the first inspection and maintenance period of a fastening structure at the root of helicopter blade.

  14. A durability model incorporating safe life methodology and damage tolerance approach to assess first inspection and maintenance period for structures

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, J.J. [Aircraft Department, Beihang University, Beijing 100083 (China); Shenoi, R.A. [School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ (United Kingdom)], E-mail: r.a.shenoi@ship.soton.ac.uk

    2009-08-15

    This paper outlines a new durability model to assess the first inspection and maintenance period for structures. Practical scatter factor formulae are presented to determine the safe fatigue crack initiation and propagation lives from the results of a single full-scale test of a complete structure. New theoretical solutions are proposed to determine the s{sub a}-s{sub m}-N surfaces of fatigue crack initiation and propagation. Prediction techniques are then developed to establish the relationship equation between safe fatigue crack initiation and propagation lives with a specific reliability level using a two-stage fatigue damage cumulative rule. A new durability model incorporating safe life and damage tolerance design approaches is derived to assess the first inspection and maintenance period. Finally, the proposed models are applied to assess the first inspection and maintenance period of a fastening structure at the root of helicopter blade.

  15. Using adaptive model predictive control to customize maintenance therapy chemotherapeutic dosing for childhood acute lymphoblastic leukemia.

    Science.gov (United States)

    Noble, Sarah L; Sherer, Eric; Hannemann, Robert E; Ramkrishna, Doraiswami; Vik, Terry; Rundell, Ann E

    2010-06-07

    Acute lymphoblastic leukemia (ALL) is a common childhood cancer in which nearly one-quarter of patients experience a disease relapse. However, it has been shown that individualizing therapy for childhood ALL patients by adjusting doses based on the blood concentration of active drug metabolite could significantly improve treatment outcome. An adaptive model predictive control (MPC) strategy is presented in which maintenance therapy for childhood ALL is personalized using routine patient measurements of red blood cell mean corpuscular volume as a surrogate for the active drug metabolite concentration. A clinically relevant mathematical model is developed and used to describe the patient response to the chemotherapeutic drug 6-mercaptopurine, with some model parameters being patient-specific. During the course of treatment, the patient-specific parameters are adaptively identified using recurrent complete blood count measurements, which sufficiently constrain the patient parameter uncertainty to support customized adjustments of the drug dose. While this work represents only a first step toward a quantitative tool for clinical use, the simulated treatment results indicate that the proposed mathematical model and adaptive MPC approach could serve as valuable resources to the oncologist toward creating a personalized treatment strategy that is both safe and effective. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  16. Revised nonstochastic health effects models

    International Nuclear Information System (INIS)

    Yaniv, S.S.; Scott, B.R.

    1991-01-01

    In 1989, the U.S. Nuclear Regulatory Commission (NRC) published a revision of the 1985 report, Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, NUREG/CR-4214, that included models for early occurring and continuing nonstochastic effects, cancers and thyroid nodules, and genetic effects. This paper discusses specific models for lethality from early occurring and continuing effects. For brevity, hematopoietic-syndrome lethality is called hematopoietic death; pulmonary-syndrome lethality is called pulmonary death; and gastrointestinal syndrome lethality is called gastrointestinal death. Two-parameter Weibull risk functions are recommended for estimating the risk of hematopoietic, pulmonary, or gastrointestinal death. The risks are obtained indirectly by using hazard functions; as a result, this type of approach has been called hazard-function modeling and the models generated are called hazard-function models. In the 1989 NUREG/CR-4214 report, changes were made in the parameter values for a number of effects, and the models used to estimate hematopoietic and pulmonary deaths were substantially revised. Upper and lower estimates of model parameters are provided for all early health effects models. In this paper, we discuss the 1989 models for hematopoietic and pulmonary deaths, highlighting the differences between the 1989 and 1985 models. In addition, we give the reasons for which the 1985 models were modified

  17. Optimization of calculation models of maintenance offers for new civil engines

    OpenAIRE

    Pechoutre, Jean-Baptiste

    2011-01-01

    The sales support department performs calculations concerning maintenance offerings for civil engines based on the use of complex tools. This report describes the missions conducted during my Master's thesis: firstly, the establishment of a monitoring and security tool in the process of calculating maintenance costs. The second achievement is the creation of a tool for decision support in order to estimate and compare some of the maintenance costs associated with the use of the new commercial...

  18. PENERAPAN MODEL PREVENTIVE MAINTENANCE SMITH DAN DEKKER DI PD. INDUSTRI UNIT INKABA

    Directory of Open Access Journals (Sweden)

    Hari Adianto

    2005-01-01

    Full Text Available The globalization era along with fast development of technology%2C industries must try to increase the quantity and quality of products that they have produced. The development of industrial products which have been increase continually need support from fluency of production process. In this case the industrial companies want a high availability system. PD Industri Unit Inkaba is one of the companies that moves in sector rubber technique industry. The company wants the production process go smoothly so that the company can keeps the existence and increases the product’s quality with cost efficiency and can competes with foreign markets. The smoothness of production process needs support from machines or production’s tools that have good condition. To keep the machines in good condition so that they will in the optimal condition when used%2C then the machines need to be maintained. M.A.J. Smith dan R. Dekker develop a model that combine availability model and preventive maintenance and consider the expected uptime and downtime of the system. This model is a 1 out of n system model%2C which has one operating machine and support by (n – 1 unit machine reserves. A 1 out of n system is also applicable to replaceable components. Smith and Dekker’s model gives the expected uptime and downtime of the system approximation that can gives good approximation of long term average operating cost. The results from decision of component preventive replacement age and optimal number of component reserve are expected to be able to keep the reliability system and be able to avoid the decease of availability system because of maintenance activity. Abstract in Bahasa Indonesia : Dalam era persaingan industri yang semakin global disertai perkembangan teknologi yang pesat%2C industri-industri terus berusaha meningkatkan kuantitas dan kualitas produk yang dihasilkannya. Perkembangan hasil industri yang semakin meningkat secara terus-menerus memerlukan dukungan

  19. Integrated internist - addiction medicine - hepatology model for hepatitis C management for individuals on methadone maintenance.

    Science.gov (United States)

    Martinez, A D; Dimova, R; Marks, K M; Beeder, A B; Zeremski, M; Kreek, M J; Talal, A H

    2012-01-01

    Despite a high prevalence of hepatitis C virus (HCV) among drug users, HCV evaluation and treatment acceptance are extremely low among these patients when referred from drug treatment facilities for HCV management. We sought to increase HCV treatment effectiveness among patients from a methadone maintenance treatment program (MMTP) by maintaining continuity of care. We developed, instituted and retrospectively assessed the effectiveness of an integrated, co-localized care model in which an internist-addiction medicine specialist from MMTP was embedded in the hepatitis clinic. Methadone maintenance treatment program patients were referred, evaluated by the internist and hepatologist in hepatitis clinic and provided HCV treatment with integration between both sites. Of 401 evaluated patients, anti-HCV antibody was detected in 257, 86% of whom were older than 40 years. Hepatitis C virus RNA levels were measured in 222 patients, 65 of whom were aviremic. Of 157 patients with detectable HCV RNA, 125 were eligible for referral to the hepatitis clinic, 76 (61%) of whom accepted and adhered with the referral. Men engaged in MMTP <36 months were significantly less likely to be seen in hepatitis clinic than men in MMTP more than 36 months (odds ratio = 7.7; 95% confidence interval 2.6-22.9) or women. We evaluated liver histology in 63 patients, and 83% had moderate to advanced liver disease. Twenty-four patients initiated treatment with 19 completing and 13 (54%) achieving sustained response. In conclusion, integrated care between the MMTP and the hepatitis clinic improves adherence with HCV evaluation and treatment compared to standard referral practices. © 2010 Blackwell Publishing Ltd.

  20. Intermediate report of MoReMo. Modelling resilience for maintenance and outage

    Energy Technology Data Exchange (ETDEWEB)

    Oedewald, P.; Macchi, L. (VTT Technical Research Centre of Finland (Finland)); Axelsson, C. (Ringhals AB, Vattenfall AB (Sweden)); Eitrheim, M.H.R. (Institute for Energy Technology (Norway))

    2012-02-15

    Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

  1. Intermediate report of MoReMo. Modelling resilience for maintenance and outage

    International Nuclear Information System (INIS)

    Oedewald, P.; Macchi, L.; Axelsson, C.; Eitrheim, M.H.R.

    2012-02-01

    Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

  2. A condition-based maintenance of a dependent degradation-threshold-shock model in a system with multiple degradation processes

    International Nuclear Information System (INIS)

    Caballé, N.C.; Castro, I.T.; Pérez, C.J.; Lanza-Gutiérrez, J.M.

    2015-01-01

    This paper proposes a condition-based maintenance strategy for a system subject to two dependent causes of failure: degradation and sudden shocks. The internal degradation is reflected by the presence of multiple degradation processes in the system. Degradation processes start at random times following a Non-homogeneous Poisson process and their growths are modelled by using a gamma process. When the deterioration level of a degradation process exceeds a predetermined value, we assume that a degradation failure occurs. Furthermore, the system is subject to sudden shocks that arrive at the system following a Doubly Stochastic Poisson Process. A sudden shock provokes the total breakdown of the system. Thus, the state of the system is evaluated at inspection times and different maintenance tasks can be carried out. If the system is still working at an inspection time, a preventive maintenance task is performed if the deterioration level of a degradation process exceeds a certain threshold. A corrective maintenance task is performed if the system is down at an inspection time. A preventive (corrective) maintenance task implies the replacement of the system by a new one. Under this maintenance strategy, the expected cost rate function is obtained. A numerical example illustrates the analytical results. - Highlights: • A condition-based maintenance model is proposed. • Two dependent causes of failure are considered: deterioration and external shocks. • Deterioration is given by multiple degradation processes growing by a gamma process. • The initiation of degradation processes follows a Non-homogeneous Poisson process. • External shocks arrive at the system by using a Doubly Stochastic Poisson Process

  3. Lin28b is sufficient to drive liver cancer and necessary for its maintenance in murine models

    Science.gov (United States)

    Nguyen, Liem H.; Robinton, Daisy A.; Seligson, Marc; Wu, Linwei; Li, Lin; Rakheja, Dinesh; Comerford, Sarah; Ramezani, Saleh; Sun, Xiankai; Parikh, Monisha; Yang, Erin; Powers, John T.; Shinoda, Gen; Shah, Samar; Hammer, Robert; Daley, George Q.; Zhu, Hao

    2014-01-01

    SUMMARY Lin28a/b are RNA-binding proteins that influence stem cell maintenance, metabolism, and oncogenesis. Poorly differentiated, aggressive cancers often overexpress Lin28, but its role in tumor initiation or maintenance has not been definitively addressed. We report that LIN28B overexpression is sufficient to initiate hepatoblastoma and hepatocellular carcinoma in murine models. We also detected Lin28b overexpression in MYC-driven hepatoblastomas, and liver-specific deletion of Lin28a/b reduced tumor burden, extended latency, and prolonged survival. Both intravenous siRNA against Lin28b and conditional Lin28b deletion reduced tumor burden and prolonged survival. Igf2bp proteins are upregulated and Igf2bp3 is required in the context of LIN28B overexpression to promote growth. Thus, multiple murine models demonstrate that Lin28b is both sufficient to initiate liver cancer and necessary for its maintenance. PMID:25117712

  4. Two fuzzy possibilistic bi-objective zero-one programming models for outsourcing the equipment maintenance problem

    Science.gov (United States)

    Vahdani, Behnam; Jolai, Fariborz; Tavakkoli-Moghaddam, Reza; Meysam Mousavi, S.

    2012-07-01

    Maintenance outsourcing can be regarded as a strategic weapon to increase productivity and customer satisfaction in many companies, and this critical activity can be performed in a more efficient and effective way. This article presents two novel fuzzy possibilistic bi-objective zero-one programming (FPBOZOP) models for outsourcing of the equipment maintenance. In these models, cost parameters, including outsourcing cost, risk cost, time operations for performing the equipment maintenance and reliability level, as well as other influential parameters are considered through the outsourcing process. Moreover, the presented models can measure the capability of the company in doing different activities, unlike previous studies, in order to see the possibility of maintenance in-house, and can lead to make a best decision on the basis of the models' results. Both models are developed under uncertainty, which bring top managers the possibility of assigning more than one equipment or project to the supplier so that the profit is maximized, and the cost is minimized by considering bi-objectives concurrently. Then, a new fuzzy mathematical programming based possibilistic approach is introduced as a solution methodology from the recent literature to solve the proposed bi-objective zero-one programming (BOZOP) models and to reach a preferred compromise solution. Furthermore, a real-case study is utilized to demonstrate and to validate the effectiveness of the presented models. The computational results revealed that the models can be implemented in variety of problems in the domain of the equipment maintenance outsourcing and project outsourcing either from theory or application perspectives.

  5. The development and application of composite complexity models and a relative complexity metric in a software maintenance environment

    Science.gov (United States)

    Hops, J. M.; Sherif, J. S.

    1994-01-01

    A great deal of effort is now being devoted to the study, analysis, prediction, and minimization of software maintenance expected cost, long before software is delivered to users or customers. It has been estimated that, on the average, the effort spent on software maintenance is as costly as the effort spent on all other software costs. Software design methods should be the starting point to aid in alleviating the problems of software maintenance complexity and high costs. Two aspects of maintenance deserve attention: (1) protocols for locating and rectifying defects, and for ensuring that noe new defects are introduced in the development phase of the software process; and (2) protocols for modification, enhancement, and upgrading. This article focuses primarily on the second aspect, the development of protocols to help increase the quality and reduce the costs associated with modifications, enhancements, and upgrades of existing software. This study developed parsimonious models and a relative complexity metric for complexity measurement of software that were used to rank the modules in the system relative to one another. Some success was achieved in using the models and the relative metric to identify maintenance-prone modules.

  6. Economic outcomes of maintenance gefitinib for locally advanced/metastatic non-small-cell lung cancer with unknown EGFR mutations: a semi-Markov model analysis.

    Directory of Open Access Journals (Sweden)

    Xiaohui Zeng

    Full Text Available BACKGROUND: Maintenance gefitinib significantly prolonged progression-free survival (PFS compared with placebo in patients from eastern Asian with locally advanced/metastatic non-small-cell lung cancer (NSCLC after four chemotherapeutic cycles (21 days per cycle of first-line platinum-based combination chemotherapy without disease progression. The objective of the current study was to evaluate the cost-effectiveness of maintenance gefitinib therapy after four chemotherapeutic cycle's stand first-line platinum-based chemotherapy for patients with locally advanced or metastatic NSCLC with unknown EGFR mutations, from a Chinese health care system perspective. METHODS AND FINDINGS: A semi-Markov model was designed to evaluate cost-effectiveness of the maintenance gefitinib treatment. Two-parametric Weibull and Log-logistic distribution were fitted to PFS and overall survival curves independently. One-way and probabilistic sensitivity analyses were conducted to assess the stability of the model designed. The model base-case analysis suggested that maintenance gefitinib would increase benefits in a 1, 3, 6 or 10-year time horizon, with incremental $184,829, $19,214, $19,328, and $21,308 per quality-adjusted life-year (QALY gained, respectively. The most sensitive influential variable in the cost-effectiveness analysis was utility of PFS plus rash, followed by utility of PFS plus diarrhoea, utility of progressed disease, price of gefitinib, cost of follow-up treatment in progressed survival state, and utility of PFS on oral therapy. The price of gefitinib is the most significant parameter that could reduce the incremental cost per QALY. Probabilistic sensitivity analysis indicated that the cost-effective probability of maintenance gefitinib was zero under the willingness-to-pay (WTP threshold of $16,349 (3 × per-capita gross domestic product of China. The sensitivity analyses all suggested that the model was robust. CONCLUSIONS: Maintenance gefitinib

  7. Model for cost economic analysis in the maintenance of distribution networks

    International Nuclear Information System (INIS)

    Flores, N.; Leite, O.C.; Abe, R.Y.; Violante, R.A.

    1989-01-01

    A methodology for evaluating the costs from aerial distribution networks maintenance is described, aiming give a tool for the planning decisions, with the purpose to keeping the system operating in equilibrium conditions between the resources invested on the preventive and corrective maintenance. (C.G.C.)

  8. The role of nutrition in caries prevention and maintenance of oral health during pregnancy

    OpenAIRE

    Jevtić Marija; Pantelinac Jelena; Jovanović-Ilić Tatjana; Petrović Vasa; Grgić Olja; Blažić Larisa

    2015-01-01

    Introduction. Pregnancy may pose an increased risk for the development of caries and other oral health problems. Continuous screening of oral health status, implementing appropriate preventive measures (particularly oral hygiene, healthy diet plans and education) is of paramount importance not only for oral health but also for the general health status of the future mother and her offspring. Effects of Food on Caries Development. Caries prevention through h...

  9. Numerical modelling to assess maintenance strategy management options for a small tidal inlet

    Science.gov (United States)

    Shaeri, Saeed; Tomlinson, Rodger; Etemad-Shahidi, Amir; Strauss, Darrell

    2017-03-01

    Small tidal inlets are found to be more sensitive to anthropogenic alteration than their larger counterparts. Such alterations, although typically supported by technical design reports, sometimes require amendments or modification. One of the most suitable tools to conduct the necessary studies in this regard is numerical modelling, since the behaviour of the inlet system in response to proposed remedial actions, can easily be identified. In this paper, various alternative proposals are investigated to determine the most practical and viable option to mitigate the need for ongoing maintenance at a typical small, jettied tidal inlet. The main tool to investigate the alternatives is the hydro-sedimentological modelling of the inlet system, which was performed using the Delft3D software package. The proposed alternative entrance modifications were based upon structural alterations of the inlet system (such as a jetty extension or submerged weir) and non-structural scenarios (such as a change of the time of the dredging campaign or the deposition location of the dredged material). It was concluded that whilst a detailed study is inevitable in order to achieve a comprehensive design plan, based upon the results of this study the construction of a submerged weir at the entrance channel can satisfy the needs of most of the stakeholders, with justifiable costs over a longer period.

  10. A risk based model supporting long term maintenance and reinvestment strategy decision making

    Energy Technology Data Exchange (ETDEWEB)

    Sand, Kjell; Montard, Julien; Tremoen, Tord H.

    2010-02-15

    This Technical Report is a product from the project Risk-Based Distribution System Asset Management (short: RISK DSAM) - Work Package 3 Risk exposure on company/strategic level. In the report a concept for portfolio distribution system asset management is presented. The approach comprises four main steps: 1. Decide the asset base. 2. Divide the asset base into relevant archetypes. 3. Develop or select relevant maintenance and reinvestment strategies for the different archetypes. 4. Estimate risks and costs for each archetype for the relevant strategies. For the different steps guidelines are given and a proposal for implementation of the concept is given in terms of a proposed IT system architecture.To evaluate the feasibility of such a concept, a prototype was developed in by using Visual Basic macros in Excel using real technical data from a small DSO. The experience from using the prototype shows that the concept is realistic. All assets are included and depending of the ambition of the risk analysis both simple simulation models and more advanced might be embedded. Presentations of the concept for a utility engineers have receive positive feedback indicating that the concept is regarded as a practical way to develop risk based asset management strategies for the asset fleet. It should be noted that the concept should be applied on a company strategic level and is thus not designed to be applied for a specific project or asset decisions. For this, more detailed models with area specific information, topology etc. are needed. (Author)

  11. The limiting conditional probability distribution in a stochastic model of T cell repertoire maintenance.

    Science.gov (United States)

    Stirk, Emily R; Lythe, Grant; van den Berg, Hugo A; Hurst, Gareth A D; Molina-París, Carmen

    2010-04-01

    The limiting conditional probability distribution (LCD) has been much studied in the field of mathematical biology, particularly in the context of epidemiology and the persistence of epidemics. However, it has not yet been applied to the immune system. One of the characteristic features of the T cell repertoire is its diversity. This diversity declines in old age, whence the concepts of extinction and persistence are also relevant to the immune system. In this paper we model T cell repertoire maintenance by means of a continuous-time birth and death process on the positive integers, where the origin is an absorbing state. We show that eventual extinction is guaranteed. The late-time behaviour of the process before extinction takes place is modelled by the LCD, which we prove always exists for the process studied here. In most cases, analytic expressions for the LCD cannot be computed but the probability distribution may be approximated by means of the stationary probability distributions of two related processes. We show how these approximations are related to the LCD of the original process and use them to study the LCD in two special cases. We also make use of the large N expansion to derive a further approximation to the LCD. The accuracy of the various approximations is then analysed. (c) 2009 Elsevier Inc. All rights reserved.

  12. Modeling the Personal Health Ecosystem.

    Science.gov (United States)

    Blobel, Bernd; Brochhausen, Mathias; Ruotsalainen, Pekka

    2018-01-01

    Complex ecosystems like the pHealth one combine different domains represented by a huge variety of different actors (human beings, organizations, devices, applications, components) belonging to different policy domains, coming from different disciplines, deploying different methodologies, terminologies, and ontologies, offering different levels of knowledge, skills, and experiences, acting in different scenarios and accommodating different business cases to meet the intended business objectives. For correctly modeling such systems, a system-oriented, architecture-centric, ontology-based, policy-driven approach is inevitable, thereby following established Good Modeling Best Practices. However, most of the existing standards, specifications and tools for describing, representing, implementing and managing health (information) systems reflect the advancement of information and communication technology (ICT) represented by different evolutionary levels of data modeling. The paper presents a methodology for integrating, adopting and advancing models, standards, specifications as well as implemented systems and components on the way towards the aforementioned ultimate approach, so meeting the challenge we face when transforming health systems towards ubiquitous, personalized, predictive, preventive, participative, and cognitive health and social care.

  13. A randomized controlled open trial of population-based disease and case management in a Medicare Plus Choice health maintenance organization.

    Science.gov (United States)

    Martin, David C; Berger, Marc L; Anstatt, David T; Wofford, Jonathan; Warfel, DeAnn; Turpin, Robin S; Cannuscio, Carolyn C; Teutsch, Steven M; Mansheim, Bernard J

    2004-10-01

    The object of this study was to examine the effect of population-based disease management and case management on resource use, self-reported health status, and member satisfaction with and retention in a Medicare Plus Choice health maintenance organization (HMO). Study design consisted of a prospective, randomized controlled open trial of 18 months' duration. Participants were 8504 Medicare beneficiaries aged 65 and older who had been continuously enrolled for at least 12 months in a network model Medicare Plus Choice HMO serving a contiguous nine-county metropolitan area. Members were care managed with an expert clinical information system and frequent telephone contact. Main outcomes included self-reported health status measured by the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), resource use measured by admission rates and bed-days per thousand per year, member satisfaction, and costs measured by paid claims. More favorable outcomes occurred in the intervention group for satisfaction with the health plan (P management and case management led to improved self-reported satisfaction and social function but not to a global net decrease in resource use or improved member retention.

  14. Dynamic Action of Carotenoids in Cardioprotection and Maintenance of Cardiac Health

    Directory of Open Access Journals (Sweden)

    Dipak K. Das

    2012-04-01

    Full Text Available Oxidative stress has been considered universally and undeniably implicated in the pathogenesis of all major diseases, including those of the cardiovascular system. Oxidative stress activate transcriptional messengers, such as nuclear factor—κB, tangibly contributing to endothelial dysfunction, the initiation and progression of atherosclerosis, irreversible damage after ischemic reperfusion, and even arrhythmia, such as atrial fibrillation. Evidence is rapidly accumulating to support the role of reactive oxygen species (ROS and reactive nitrogen species (RNS as intracellular signaling molecules. Despite this connection between oxidative stress and cardiovascular disease (CVD, there are currently no recognized therapeutic interventions to address this important unmet need. Antioxidants that provide a broad, “upstream” approach via ROS/RNS quenching or free radical chain breaking seem an appropriate therapeutic option based on epidemiologic, dietary, and in vivo animal model data. Short-term dietary intervention trials suggest that diets rich in fruit and vegetable intake lead to improvements in coronary risk factors and reduce cardiovascular mortality. Carotenoids are such abundant, plant-derived, fat-soluble pigments that functions as antioxidants. They are stored in the liver or adipose tissue, and are lipid soluble by becoming incorporated into plasma lipoprotein particles during transport. For these reasons, carotenoids may represent one plausible mechanism by which fruits and vegetables reduce the risk of chronic diseases as cardiovascular disease (CVD. This review paper outlines the role of carotenoids in maintaining cardiac health and cardioprotection mediated by several mechanisms including redox signaling.

  15. A new multi-objective optimization model for preventive maintenance and replacement scheduling of multi-component systems

    Science.gov (United States)

    Moghaddam, Kamran S.; Usher, John S.

    2011-07-01

    In this article, a new multi-objective optimization model is developed to determine the optimal preventive maintenance and replacement schedules in a repairable and maintainable multi-component system. In this model, the planning horizon is divided into discrete and equally-sized periods in which three possible actions must be planned for each component, namely maintenance, replacement, or do nothing. The objective is to determine a plan of actions for each component in the system while minimizing the total cost and maximizing overall system reliability simultaneously over the planning horizon. Because of the complexity, combinatorial and highly nonlinear structure of the mathematical model, two metaheuristic solution methods, generational genetic algorithm, and a simulated annealing are applied to tackle the problem. The Pareto optimal solutions that provide good tradeoffs between the total cost and the overall reliability of the system can be obtained by the solution approach. Such a modeling approach should be useful for maintenance planners and engineers tasked with the problem of developing recommended maintenance plans for complex systems of components.

  16. Random maintenance policies

    CERN Document Server

    Nakagawa, Toshio

    2014-01-01

    Exploring random maintenance models, this book provides an introduction to the implementation of random maintenance, and it is one of the first books to be written on this subject.  It aims to help readers learn new techniques for applying random policies to actual reliability models, and it provides new theoretical analyses of various models including classical replacement, preventive maintenance and inspection policies. These policies are applied to scheduling problems, backup policies of database systems, maintenance policies of cumulative damage models, and reliability of random redundant systems. Reliability theory is a major concern for engineers and managers, and in light of Japan’s recent earthquake, the reliability of large-scale systems has increased in importance. This also highlights the need for a new notion of maintenance and reliability theory, and how this can practically be applied to systems. Providing an essential guide for engineers and managers specializing in reliability maintenance a...

  17. A Simulation Model for Machine Efficiency Improvement Using Reliability Centered Maintenance: Case Study of Semiconductor Factory

    Directory of Open Access Journals (Sweden)

    Srisawat Supsomboon

    2014-01-01

    Full Text Available The purpose of this study was to increase the quality of product by focusing on the machine efficiency improvement. The principle of the reliability centered maintenance (RCM was applied to increase the machine reliability. The objective was to create preventive maintenance plan under reliability centered maintenance method and to reduce defects. The study target was set to reduce the Lead PPM for a test machine by simulating the proposed preventive maintenance plan. The simulation optimization approach based on evolutionary algorithms was employed for the preventive maintenance technique selection process to select the PM interval that gave the best total cost and Lead PPM values. The research methodology includes procedures such as following the priority of critical components in test machine, analyzing the damage and risk level by using Failure Mode and Effects Analysis (FMEA, calculating the suitable replacement period through reliability estimation, and optimizing the preventive maintenance plan. From the result of the study it is shown that the Lead PPM of test machine can be reduced. The cost of preventive maintenance, cost of good product, and cost of lost product were decreased.

  18. [Does good oral hygiene guarantee the maintenance of a health periodontium?].

    Science.gov (United States)

    Temmerman, A; Dekeyser, C; Quirynen, M

    2010-01-01

    On the last European Workshop for Periodontology, it was accepted that the prevalence of periodontitis in certain regions of Europe and USA has decreased. It remains difficult to phrase a decision concerning the prevalence of periodontitis in general. This article wants to highlight the need of a good oral hygiene and different forms of prevention (primary, secondary & tertiary) in the maintenance of a healthy periodontium. The relationship between gingivitis and tooth loss is pointed out. The prevention is described in the complexity of the periodontitis proces and it's modifying factors. When dealing with different forms of periodontitis (refractory, necrotising gingivitis and periodontitis, agressive periodontitis) prevention needs to be adjusted to the etiology and specific situation. This is also the case in peri-implantitis. This article tends to find a scientific background for oral hygiene and prevention in periodontal disease.

  19. A reliability centered maintenance model applied to the auxiliary feedwater system of a nuclear power plant

    International Nuclear Information System (INIS)

    Araujo, Jefferson Borges

    1998-01-01

    The main objective of maintenance in a nuclear power plant is to assure that structures, systems and components will perform their design functions with reliability and availability in order to obtain a safety and economic electric power generation. Reliability Centered Maintenance (RCM) is a method of systematic review to develop or optimize Preventive Maintenance Programs. This study presents the objectives, concepts, organization and methods used in the development of RCM application to nuclear power plants. Some examples of this application are included, considering the Auxiliary Feedwater System of a generic two loops PWR nuclear power plant of Westinghouse design. (author)

  20. Assessment of a maintenance model for a multi-deteriorating mode system

    International Nuclear Information System (INIS)

    Ponchet, Amelie; Fouladirad, Mitra; Grall, Antoine

    2010-01-01

    This paper deals with maintenance policies for stochastically deteriorating systems which are subject to sudden changes in their degradation processes. The main aim is to assess the interest of using change mode monitoring information from a maintenance decision making point of view. Two condition-based maintenance policies are considered and compared, each of them adapted to a specific level of available information, with or without change mode monitoring. Numerical examples show that the time distribution of the change of deterioration rate and the difference between the two possible deterioration rates strongly influence the choice of the best decision rule structure.

  1. Assessment of a maintenance model for a multi-deteriorating mode system

    Energy Technology Data Exchange (ETDEWEB)

    Ponchet, Amelie, E-mail: amelie.ponchet@utt.f [Institut Charles Delaunay, Universite de technologie de Troyes, UMR CNRS 6279 STMR, 12 rue Marie Curie, 10010 Troyes (France); Fouladirad, Mitra [Institut Charles Delaunay, Universite de technologie de Troyes, UMR CNRS 6279 STMR, 12 rue Marie Curie, 10010 Troyes (France); Grall, Antoine, E-mail: antoine.grall@utt.f [Institut Charles Delaunay, Universite de technologie de Troyes, UMR CNRS 6279 STMR, 12 rue Marie Curie, 10010 Troyes (France)

    2010-11-15

    This paper deals with maintenance policies for stochastically deteriorating systems which are subject to sudden changes in their degradation processes. The main aim is to assess the interest of using change mode monitoring information from a maintenance decision making point of view. Two condition-based maintenance policies are considered and compared, each of them adapted to a specific level of available information, with or without change mode monitoring. Numerical examples show that the time distribution of the change of deterioration rate and the difference between the two possible deterioration rates strongly influence the choice of the best decision rule structure.

  2. Total Productive Maintenance And Role Of Interpretive Structural Modeling And Structural Equation Modeling In Analyzing Barriers In Its Implementation A Literature Review

    OpenAIRE

    Prasanth S. Poduval; Dr. Jagathy Raj V. P.; Dr. V. R. Pramod

    2015-01-01

    Abstract - The aim of the authors is to present a review of literature of Total Productive Maintenance and the barriers in implementation of Total Productive Maintenance TPM. The paper begins with a brief description of TPM and the barriers in implementation of TPM. Interpretive Structural Modeling ISM and its role in analyzing the barriers in TPM implementation is explained in brief. Applications of ISM in analyzing issues in various fields are highlighted with special emphasis on TPM. T...

  3. Cost-effectiveness of continuation maintenance pemetrexed after cisplatin and pemetrexed chemotherapy for advanced nonsquamous non-small-cell lung cancer: estimates from the perspective of the Chinese health care system.

    Science.gov (United States)

    Zeng, Xiaohui; Peng, Liubao; Li, Jianhe; Chen, Gannong; Tan, Chongqing; Wang, Siying; Wan, Xiaomin; Ouyang, Lihui; Zhao, Ziying

    2013-01-01

    Continuation maintenance treatment with pemetrexed is approved by current clinical guidelines as a category 2A recommendation after induction therapy with cisplatin and pemetrexed chemotherapy (CP strategy) for patients with advanced nonsquamous non-small-cell lung cancer (NSCLC). However, the cost-effectiveness of the treatment remains unclear. We completed a trial-based assessment, from the perspective of the Chinese health care system, of the cost-effectiveness of maintenance pemetrexed treatment after a CP strategy for patients with advanced nonsquamous NSCLC. A Markov model was developed to estimate costs and benefits. It was based on a clinical trial that compared continuation maintenance pemetrexed therapy plus best supportive care (BSC) versus placebo plus BSC after a CP strategy for advanced nonsquamous NSCLC. Sensitivity analyses were conducted to assess the stability of the model. The model base case analysis suggested that continuation maintenance pemetrexed therapy after a CP strategy would increase benefits in a 1-, 2-, 5-, or 10-year time horizon, with incremental costs of $183,589.06, $126,353.16, $124,766.68, and $124,793.12 per quality-adjusted life-year gained, respectively. The most sensitive influential variable in the cost-effectiveness analysis was the utility of the progression-free survival state, followed by proportion of patients with postdiscontinuation therapy in both arms, proportion of BSC costs for PFS versus progressed survival state, and cost of pemetrexed. Probabilistic sensitivity analysis indicated that the cost-effective probability of adding continuation maintenance pemetrexed therapy to BSC was zero. One-way and probabilistic sensitivity analyses revealed that the Markov model was robust. Continuation maintenance of pemetrexed after a CP strategy for patients with advanced nonsquamous NSCLC is not cost-effective based on a recent clinical trial. Decreasing the price or adjusting the dosage of pemetrexed may be a better option

  4. Growth of health maintenance organisations in Nigeria and the potential for a role in promoting universal coverage efforts.

    Science.gov (United States)

    Onoka, Chima A; Hanson, Kara; Mills, Anne

    2016-08-01

    There has been growing interest in the potential for private health insurance (PHI) and private organisations to contribute to universal health coverage (UHC). Yet evidence from low and middle income countries remains very thin. This paper examines the evolution of health maintenance organisations (HMOs) in Nigeria, the nature of the PHI plans and social health insurance (SHI) programmes and their performance, and the implications of their business practices for providing PHI and UHC-related SHI programmes. An embedded case study design was used with multiple subunits of analysis (individual HMOs and the HMO industry) and mixed (qualitative and quantitative) methods, and the study was guided by the structure-conduct-performance paradigm that has its roots in the neo-classical theory of the firm. Quantitative data collection and 35 in-depth interviews were carried out between October 2012 to July 2013. Although HMOs first emerged in Nigeria to supply PHI, their expansion was driven by their role as purchasers in the government's national health insurance scheme that finances SHI programmes, and facilitated by a weak accreditation system. HMOs' characteristics distinguish the market they operate in as monopolistically competitive, and HMOs as multiproduct firms operating multiple risk pools through parallel administrative systems. The considerable product differentiation and consequent risk selection by private insurers promote inefficiencies. Where HMOs and similar private organisations play roles in health financing systems, effective regulatory institutions and mandates must be established to guide their behaviours towards attainment of public health goals and to identify and control undesirable business practices. Lessons are drawn for policy makers and programme implementers especially in those low and middle-income countries considering the use of private organisations in their health financing systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. A New Biobjective Model to Optimize Integrated Redundancy Allocation and Reliability-Centered Maintenance Problems in a System Using Metaheuristics

    Directory of Open Access Journals (Sweden)

    Shima MohammadZadeh Dogahe

    2015-01-01

    Full Text Available A novel integrated model is proposed to optimize the redundancy allocation problem (RAP and the reliability-centered maintenance (RCM simultaneously. A system of both repairable and nonrepairable components has been considered. In this system, electronic components are nonrepairable while mechanical components are mostly repairable. For nonrepairable components, a redundancy allocation problem is dealt with to determine optimal redundancy strategy and number of redundant components to be implemented in each subsystem. In addition, a maintenance scheduling problem is considered for repairable components in order to identify the best maintenance policy and optimize system reliability. Both active and cold standby redundancy strategies have been taken into account for electronic components. Also, net present value of the secondary cost including operational and maintenance costs has been calculated. The problem is formulated as a biobjective mathematical programming model aiming to reach a tradeoff between system reliability and cost. Three metaheuristic algorithms are employed to solve the proposed model: Nondominated Sorting Genetic Algorithm (NSGA-II, Multiobjective Particle Swarm Optimization (MOPSO, and Multiobjective Firefly Algorithm (MOFA. Several test problems are solved using the mentioned algorithms to test efficiency and effectiveness of the solution approaches and obtained results are analyzed.

  6. Maintenance of polygenic sex determination in a fluctuating environment: an individual-based model.

    Science.gov (United States)

    Bateman, A W; Anholt, B R

    2017-05-01

    R. A. Fisher predicted that individuals should invest equally in offspring of both sexes, and that the proportion of males and females produced (the primary sex ratio) should evolve towards 1:1 when unconstrained. For many species, sex determination is dependent on sex chromosomes, creating a strong tendency for balanced sex ratios, but in other cases, multiple autosomal genes interact to determine sex. In such cases, the maintenance of multiple sex-determining alleles at multiple loci and the consequent among-family variability in sex ratios presents a puzzle, as theory predicts that such systems should be unstable. Theory also predicts that environmental influences on sex can complicate outcomes of genetic sex determination, and that population structure may play a role. Tigriopus californicus, a copepod that lives in splash-pool metapopulations and exhibits polygenic and environment-dependent sex determination, presents a test case for relevant theory. We use this species as a model for parameterizing an individual-based simulation to investigate conditions that could maintain polygenic sex determination. We find that metapopulation structure can delay the degradation of polygenic sex determination and that periods of alternating frequency-dependent selection, imposed by seasonal fluctuations in environmental conditions, can maintain polygenic sex determination indefinitely. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  7. MODELING A COMPUTER APPLICATION FOR MANAGEMENT OF MAINTENANCE ACTIVITIES OF UNPAVED ROADS

    Directory of Open Access Journals (Sweden)

    Ludmília de Souza Dias

    2015-08-01

    Full Text Available ABSTRACTThis study presents a contribution to the modeling of a computer application employing a method of serviceability performance for unpaved roads, aiming the management of maintenance/restoration activities of the primary surface layer. The proposed methodology consisted of field inspections during dry (April to September and rainy (October to March periods, during which objective evaluations were performed to survey of defects and their densities and degrees of severity. To aid the functional classification of analyzed road sections and the determination of the defect with major influence on the serviceability of these roads, the method of serviceability performance proposed by Silva (2009was implemented in the Visual Basic for Applications (VBA language in Microsoft Excel software. With the use of the computer application proposed it was possible to identify among the defects analyzed in field, through the index of serviceability of the sampling unit per defect type (ISUdef, which one had the greatest influence on determining the relative serviceability index per road section (IST. The results allow us to conclude that the computer application Road achieved satisfactory results, since the objective evaluation criteria applied to road sections denotes consistency regarding their serviceability.

  8. Fabrication of nuclear ship reactor MRX model and study on inspection and maintenance of components

    International Nuclear Information System (INIS)

    Kasahara, Yoshiyuki; Nakazawa, Toshio; Kusunoki, Tsuyoshi; Takahashi, Hiroki; Yoritsune, Tsutomu.

    1997-10-01

    The MRX (Marine Reactor X) is an integral type small reactor adopting passive safety systems. As for an integral type reactor, primary system components are installed in the reactor vessel. It is therefor important to establish the appropriate procedure for construction, inspection and maintenance, dismauntling, etc., for all components in the reactor vessel as well as in the reactor containment, because inspection space is limited. To study these subjects, a one-fifth model of the MRX was fabricated and operation capabilities were studied. As a result of studies, the following results are obtained. (1) Manufacturing and installing problems of the reactor pressure vessel, the containment vessel and internal components are basically not abserved. (2) Heat transfer tube structures of the steam generator and the heat exchangers of emergency decay heat removal system and containment water cooler were not seen of any problem for fabrication. However, due consideration is required in the detailed design of supports of heat transfer tubes. (3) Further studies should be needed for designs of flange penetrations and leak countermeasures for pipes instrument cables. (4) Arrangements of equipments in the containment should be taken in consideration in detail because the space is narrow. (5) Further discussion is required for installation methods of instruments and cables. (author)

  9. The plant operating procedure information modeling system for creation and maintenance of procedures

    International Nuclear Information System (INIS)

    Fanto, S.V.; Petras, D.S.; Reiner, R.T.; Frost, D.R.; Orendi, R.G.

    1990-01-01

    This paper reports that as a result of the accident at Three Mile Island, regulatory requirements were issued to upgrade Emergency Operating Procedures for nuclear power plants. The use of human-factored, function-oriented, EOPs were mandated to improve human reliability and to mitigate the consequences of a broad range of initiating events, subsequent failures and operator errors, without having to first diagnose the specific events. The Westinghouse Owners Group responded by developing the Emergency Response Guidelines in a human-factored, two-column format to aid in the transfer of the improved technical information to the operator during transients and accidents. The ERGs are a network of 43 interrelated guidelines which specify operator actions to be taken during plant emergencies to restore the plant to a safe and stable condition. Each utility then translates these guidelines into plant specific EOPs. The creation and maintenance of this large web of interconnecting ERGs/EOPs is an extremely complex task. This paper reports that in order to aid procedure documentation specialists with this time-consuming and tedious task, the Plant Operating Procedure Information Modeling system was developed to provide a controlled and consistent means to build and maintain the ERGs/EOPs and their supporting documentation

  10. Calibration model maintenance in melamine resin production: Integrating drift detection, smart sample selection and model adaptation.

    Science.gov (United States)

    Nikzad-Langerodi, Ramin; Lughofer, Edwin; Cernuda, Carlos; Reischer, Thomas; Kantner, Wolfgang; Pawliczek, Marcin; Brandstetter, Markus

    2018-07-12

    The physico-chemical properties of Melamine Formaldehyde (MF) based thermosets are largely influenced by the degree of polymerization (DP) in the underlying resin. On-line supervision of the turbidity point by means of vibrational spectroscopy has recently emerged as a promising technique to monitor the DP of MF resins. However, spectroscopic determination of the DP relies on chemometric models, which are usually sensitive to drifts caused by instrumental and/or sample-associated changes occurring over time. In order to detect the time point when drifts start causing prediction bias, we here explore a universal drift detector based on a faded version of the Page-Hinkley (PH) statistic, which we test in three data streams from an industrial MF resin production process. We employ committee disagreement (CD), computed as the variance of model predictions from an ensemble of partial least squares (PLS) models, as a measure for sample-wise prediction uncertainty and use the PH statistic to detect changes in this quantity. We further explore supervised and unsupervised strategies for (semi-)automatic model adaptation upon detection of a drift. For the former, manual reference measurements are requested whenever statistical thresholds on Hotelling's T 2 and/or Q-Residuals are violated. Models are subsequently re-calibrated using weighted partial least squares in order to increase the influence of newer samples, which increases the flexibility when adapting to new (drifted) states. Unsupervised model adaptation is carried out exploiting the dual antecedent-consequent structure of a recently developed fuzzy systems variant of PLS termed FLEXFIS-PLS. In particular, antecedent parts are updated while maintaining the internal structure of the local linear predictors (i.e. the consequents). We found improved drift detection capability of the CD compared to Hotelling's T 2 and Q-Residuals when used in combination with the proposed PH test. Furthermore, we found that active

  11. Analysis and Maintenance of Mental Health of Female Teachers in Colleges of China

    Science.gov (United States)

    Zhang, Yin-ling; Cao, Bao-hua; Miao, Dan-min

    2006-01-01

    Mental health has received increasing attention over the past few years as a common problem with serious consequences for the health and well-being of the people. But there is little attention paid to the problem for the special group of population, female teachers in China's colleges. Most of them are in a dilemma of how to perform and harmonize…

  12. Maintenance of behaviour change after a 12-week mHealth lifestyle programme for young adults.

    Directory of Open Access Journals (Sweden)

    Margaret Allman-Farinelli

    2015-09-01

    Conclusions: Young adulthood is a period of rapid weight gain but this group are hard to reach for health promotion. Despite the relatively low intensity of the TXT2BFiT programme, behaviours were maintained during the six months following the intervention. mHealth shows promise to deliver intervention with wide reach and low cost.

  13. Attitudes and beliefs towards methadone maintenance treatment among Australian prison health staff.

    Science.gov (United States)

    Gjersing, Linn R; Butler, Tony; Caplehorn, John R M; Belcher, Josephine M; Matthews, Richard

    2007-09-01

    Justice Health NSW has one of the most extensive prison-based methadone programmes in the world. We examine prison health staff attitudes towards methadone treatment and compare these with community methadone staff. A cross-sectional survey of 202 staff employed by Justice Health New South Wales was undertaken in 2003. Results. The mean scores on the various sub-scales were: abstinence-orientation (AO) 2.9 (95% CI 2.8 - 3.0); disapproval of drug use (DDU) 3.3 (95% CI 3.2 - 3.4); knowledge (Know) 2.7 (95% CI 2.4 - 2.9); and toxicity 4.6 (95% CI 4.2 - 5.0). Both the AO and DDU score were correlated negatively with the Know score (r = -0.37 and r = -0.13, respectively). Prison health staff had higher AO (2.9 vs. 2.6, p US community methadone staff about the toxicity of methadone (4.6 vs. 0.0, p prison health staff attitudes to methadone treatment. Correctional health staff tend to be more abstinence-orientated, more likely to disapprove of drug use, and less knowledgeable about the risks and benefits of methadone than Australian community methadone staff. The findings have important implications for training health staff working in the prison environment with regard to client retention on methadone treatment.

  14. A Proactive Aging/Asset Management Model to Optimize Equipment Maintenance Resources Over Plant Lifetime

    International Nuclear Information System (INIS)

    Meyer, Theodore A.; Perdue, Robert K.; Woodcock, Joel; Elder, G. Gary

    2002-01-01

    Experience has shown that proactive aging/asset management can best be defined as an ongoing process. Station goals directly supported by such a process include reducing Unplanned Capability Loss Factor and gaining the optimum value from maintenance and aging management budgets. An effective aging/asset management process must meet evolving and sometimes conflicting requirements for efficient and reliable nuclear power plant operation. The process should identify most likely contributors before they fail, and develop cost-effective contingencies. Current trends indicate the need for focused tools that give quantitative input to decision-making. Opposing goals, such as increasing availability while optimizing aging management budgets, must be balanced. Recognizing the importance of experience in reducing the uncertainty inherent in predicting equipment degradation rates, nuclear industry demographics suggest the need to capture existing expert knowledge in a usable form. The Proactive Aging/Asset Management Process has been developed to address these needs. The proactive approach is a process supported by tools. The process identifies goals and develops criteria - including safety, costs, and power production - that are used to prioritize systems and equipment across the plant. The process then draws upon tools to most effectively meet the plant's goals. The Proactive Aging/Asset Management Model TM is one software-enabled tool designed for mathematical optimization. Results assist a plant in developing a plant-wide plan of aging management activities. This paper describes the proactive aging/asset management process and provides an overview of the methodology that has been incorporated in a model to perform a plant-wide optimization of aging management activities. (authors)

  15. Webinar: A Proactive Approach to IAQ: Saving Money and Protecting Health With Preventive Maintenance

    Science.gov (United States)

    A page to register to view the June 22, 2017, webinar in the IAQ Knowledge-to-Action Professional Training Webinar Series: Green Cleaning for Improved Health: The Return on Investment of Green Cleaning in Schools

  16. Modeling Boston: A workflow for the efficient generation and maintenance of urban building energy models from existing geospatial datasets

    International Nuclear Information System (INIS)

    Cerezo Davila, Carlos; Reinhart, Christoph F.; Bemis, Jamie L.

    2016-01-01

    City governments and energy utilities are increasingly focusing on the development of energy efficiency strategies for buildings as a key component in emission reduction plans and energy supply strategies. To support these diverse needs, a new generation of Urban Building Energy Models (UBEM) is currently being developed and validated to estimate citywide hourly energy demands at the building level. However, in order for cities to rely on UBEMs, effective model generation and maintenance workflows are needed based on existing urban data structures. Within this context, the authors collaborated with the Boston Redevelopment Authority to develop a citywide UBEM based on official GIS datasets and a custom building archetype library. Energy models for 83,541 buildings were generated and assigned one of 52 use/age archetypes, within the CAD modelling environment Rhinoceros3D. The buildings were then simulated using the US DOE EnergyPlus simulation program, and results for buildings of the same archetype were crosschecked against data from the US national energy consumption surveys. A district-level intervention combining photovoltaics with demand side management is presented to demonstrate the ability of UBEM to provide actionable information. Lack of widely available archetype templates and metered energy data, were identified as key barriers within existing workflows that may impede cities from effectively applying UBEM to guide energy policy. - Highlights: • Data requirements for Urban Building Energy Models are reviewed. • A workflow for UBEM generation from available GIS datasets is developed. • A citywide demand simulation model for Boston is generated and tested. • Limitations for UBEM in current urban data systems are identified and discussed. • Model application for energy management policy is shown in an urban PV scenario.

  17. A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

    International Nuclear Information System (INIS)

    Wang, Wenbin; Zhao, Fei; Peng, Rui

    2014-01-01

    Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

  18. Analysis of maintenance strategies

    International Nuclear Information System (INIS)

    Laakso, K.; Simola, K.

    1998-01-01

    The main topics of the presentation include: (1) an analysis model and methods to evaluate maintenance action programs and the support decision to make changes in them and (2) to understand the maintenance strategies in a systems perspective as a basis for future developments. The subproject showed how systematic models for maintenance analysis and decision support, utilising computerised and statistical tool packages, can be taken into use for evaluation and optimisation of maintenance of active systems from the safety and economic point of view

  19. THE ROLE OF NUTRITION IN CARIES PREVENTION AND MAINTENANCE OF ORAL HEALTH DURING PREGNANCY.

    Science.gov (United States)

    Jevtić, Marija; Pantelinaci, Jelena; Jovanović Ilić, Tatjana; Petrović, Vasa; Grgić, Olja; Blazić, Larisa

    2015-01-01

    Pregnancy may pose an increased risk for the development of caries and other oral health problems. Continuous screening of oral health status, implementing appropriate preventive measures (particularly oral hygiene, healthy diet plans and education) is of paramount importance not only for oral health but also for the general health status of the future mother and her offspring. EFFECTS OF FOOD ON CARIES DEVELOPMENT: Caries prevention through healthy diet implicates the reduction in frequency and amount of intake of cariogenic food, above all ofrefined carbohydrates, i.e. sugars and sweets. Foods known to have caries-prophylactic effects should predominate in healthy diet plans. They mainly include solid foods, which have mechanical effects on teeth cleaning, as well as foods providing sufficient amounts of vitamins (A, C, D) and a variety of elements and compounds (calcium, phosphates, fluorides) favoring the preservation and remineralization of tooth structures. EDUCATION OF PREGNANT WOMEN ON HEALHY DEIT: In accomplishing these goals, education and direct positive communication between the educator and the pregnant woman play a crucial role. Educative approach is always individual and determined by the patient's specific cultural and socioeconomic features and status, as well as her habits, motivation and willingness to accept relevant recommendations. Accomplishing the aforementioned goals requires the appropriate organization and professional competence within the preventive dental service and its close cooperation with the relevant medical institutions and social support in the framework of public health protection. Preserving of oral health during pregnancy is predominantly influenced by the following factors: 1) healthy diet, 2) oral hygiene, 3) patients' education, 4) regular control of oral health, 5) appropriate organization of dental services and 6) community engagement.

  20. A two-stage preventive maintenance optimization model incorporating two-dimensional extended warranty

    International Nuclear Information System (INIS)

    Su, Chun; Wang, Xiaolin

    2016-01-01

    In practice, customers can decide whether to buy an extended warranty or not, at the time of item sale or at the end of the basic warranty. In this paper, by taking into account the moments of customers purchasing two-dimensional extended warranty, the optimization of imperfect preventive maintenance for repairable items is investigated from the manufacturer's perspective. A two-dimensional preventive maintenance strategy is proposed, under which the item is preventively maintained according to a specified age interval or usage interval, whichever occurs first. It is highlighted that when the extended warranty is purchased upon the expiration of the basic warranty, the manufacturer faces a two-stage preventive maintenance optimization problem. Moreover, in the second stage, the possibility of reducing the servicing cost over the extended warranty period is explored by classifying customers on the basis of their usage rates and then providing them with customized preventive maintenance programs. Numerical examples show that offering customized preventive maintenance programs can reduce the manufacturer's warranty cost, while a larger saving in warranty cost comes from encouraging customers to buy the extended warranty at the time of item sale. - Highlights: • A two-dimensional PM strategy is investigated. • Imperfect PM strategy is optimized by considering both two-dimensional BW and EW. • Customers are categorized based on their usage rates throughout the BW period. • Servicing cost of the EW is reduced by offering customized PM programs. • Customers buying the EW at the time of sale is preferred for the manufacturer.

  1. Evolution of portal hypertension and mechanisms involved in its maintenance in a rat model

    International Nuclear Information System (INIS)

    Sikuler, E.; Kravetz, D.; Groszmann, R.J.

    1985-01-01

    In rats with portal hypertension induced by partial ligation of the portal vein, the authors have recently demonstrated an increased portal venous inflow that becomes an important factor in the maintenance of portal hypertension. The sequence of events that leads into this circulatory disarray is unknown. The authors evaluated chronologically the chain of hemodynamic changes that occurred after portal hypertension was induced by partial ligation of the portal vein. In this model it is possible to follow, from the initiation of the portal-hypertensive state, the interaction between blood flow and resistance in the portal system as well as the relation between the development of portal-systemic shunting and the elevated portal venous inflow. The study was performed in 45 portal-hypertensive rats and in 29 sham-operated rats. Blood flow and portal-systemic shunting were measured by radioactive microsphere techniques. The constriction of the portal vein was immediately followed by a resistance-induced portal hypertension characterized by increased portal resistance (9.78 +/- 0.89 vs. 4.18 +/- 0.71 dyn X s X cm-5 X 10(4), mean +/- SE, P less than 0.01), increased portal pressure (17.7 +/- 0.9 vs. 9.5 +/- 0.6 mmHg, P less than 0.001), and decreased portal venous inflow (3.93 +/- 0.26 vs. 6.82 +/- 0.49 ml X min-1 X 100 g body wt-1, P less than 0.001)

  2. A generalized quantitative antibody homeostasis model: maintenance of global antibody equilibrium by effector functions.

    Science.gov (United States)

    Prechl, József

    2017-11-01

    The homeostasis of antibodies can be characterized as a balanced production, target-binding and receptor-mediated elimination regulated by an interaction network, which controls B-cell development and selection. Recently, we proposed a quantitative model to describe how the concentration and affinity of interacting partners generates a network. Here we argue that this physical, quantitative approach can be extended for the interpretation of effector functions of antibodies. We define global antibody equilibrium as the zone of molar equivalence of free antibody, free antigen and immune complex concentrations and of dissociation constant of apparent affinity: [Ab]=[Ag]=[AbAg]= K D . This zone corresponds to the biologically relevant K D range of reversible interactions. We show that thermodynamic and kinetic properties of antibody-antigen interactions correlate with immunological functions. The formation of stable, long-lived immune complexes correspond to a decrease of entropy and is a prerequisite for the generation of higher-order complexes. As the energy of formation of complexes increases, we observe a gradual shift from silent clearance to inflammatory reactions. These rules can also be applied to complement activation-related immune effector processes, linking the physicochemical principles of innate and adaptive humoral responses. Affinity of the receptors mediating effector functions shows a wide range of affinities, allowing the continuous sampling of antibody-bound antigen over the complete range of concentrations. The generation of multivalent, multicomponent complexes triggers effector functions by crosslinking these receptors on effector cells with increasing enzymatic degradation potential. Thus, antibody homeostasis is a thermodynamic system with complex network properties, nested into the host organism by proper immunoregulatory and effector pathways. Maintenance of global antibody equilibrium is achieved by innate qualitative signals modulating a

  3. Uncertainty and sensitivity analyses for age-dependent unavailability model integrating test and maintenance

    International Nuclear Information System (INIS)

    Kančev, Duško; Čepin, Marko

    2012-01-01

    Highlights: ► Application of analytical unavailability model integrating T and M, ageing, and test strategy. ► Ageing data uncertainty propagation on system level assessed via Monte Carlo simulation. ► Uncertainty impact is growing with the extension of the surveillance test interval. ► Calculated system unavailability dependence on two different sensitivity study ageing databases. ► System unavailability sensitivity insights regarding specific groups of BEs as test intervals extend. - Abstract: The interest in operational lifetime extension of the existing nuclear power plants is growing. Consequently, plants life management programs, considering safety components ageing, are being developed and employed. Ageing represents a gradual degradation of the physical properties and functional performance of different components consequently implying their reduced availability. Analyses, which are being made in the direction of nuclear power plants lifetime extension are based upon components ageing management programs. On the other side, the large uncertainties of the ageing parameters as well as the uncertainties associated with most of the reliability data collections are widely acknowledged. This paper addresses the uncertainty and sensitivity analyses conducted utilizing a previously developed age-dependent unavailability model, integrating effects of test and maintenance activities, for a selected stand-by safety system in a nuclear power plant. The most important problem is the lack of data concerning the effects of ageing as well as the relatively high uncertainty associated to these data, which would correspond to more detailed modelling of ageing. A standard Monte Carlo simulation was coded for the purpose of this paper and utilized in the process of assessment of the component ageing parameters uncertainty propagation on system level. The obtained results from the uncertainty analysis indicate the extent to which the uncertainty of the selected

  4. 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)

  5. Decision models for new products sold with warranty and maintenance support under stable and dynamic market

    OpenAIRE

    Darghouth, Mohamed Noomane

    2012-01-01

    Les travaux réalisés dans le cadre de cette thèse ont été initiés à partir d'une problématique formulée par un constructeur d'équipements qui souhaite offrir à son client une période de garantie sur tous les vices de conception et de fabrication ainsi que des options sur les services de maintenance durant toute la vie utile de l'équipement. Les services de maintenance comprennent des inspections pour évaluer l'état de dégradation de l'équipement, des actions de maintenance correctives (répara...

  6. Modelling And Dynamic Analysis Of Catenary Maintenance Vehicle By AdamsVI-Rail

    Directory of Open Access Journals (Sweden)

    Damla Vural Cavusoglu

    2017-06-01

    Full Text Available The railway transportation network which is become quite important in the recent times in our country and in the world is forced to make new investments by developing technology. Old trains give place to high-speed trains in consequence of the railway catenary lines and the rail systems enter into a mass renovation study. During the renovation studies it is needed the catenary maintenance vehicles which are responded the need fast with wide working area. Until this time while it is continuing the needs of these maintenance vehicles which are gained by import for our country sizeable amount of currency is exported. Thanks to this research in our country it is manufactured the catenary maintenance vehicle for the first time and while the national capital is lying within the national borders it is thought that it will be shaped a new work portfolio.

  7. Oil pulling and importance of traditional medicine in oral health maintenance.

    Science.gov (United States)

    Naseem, Mustafa; Khiyani, Muhammad Faheem; Nauman, Hiba; Zafar, Muhammad Sohail; Shah, Altaf H; Khalil, Hesham S

    2017-01-01

    Dental diseases have detrimental effects on the functionality and quality of life of individuals. In addition, a strong relationship has been established between various oral and systemic diseases. In fact, the prevention and treatment of dental caries and periodontal disease have been shown to reduce the risk of diabetes and heart disease significantly. This goes beyond the role of oral health as a means to identify early manifestations of systemic diseases in the oral cavity. It highlights the necessity of maintaining an optimal oral hygiene to significantly modify the risk factors for serious systemic diseases. The use of oil pulling can be frequently found in ancient medical text and is supported by recent studies for its efficacy and long-term use for maintaining and improving oral health. This article provides an overview on the concept of oil pulling or oil swishing, its mechanism of action and a summary of the evidence available, which highlights the role of oil pulling in specific oral diseases. The goal of this review is to highlight the ancient procedure that has the potential to be used as an adjunct to conventional chemical means of dental plaque control, such as mouth rinses. Incorporating oil swishing as a component of daily oral hygiene can significantly improve oral and general health, specifically in lower socioeconomic groups and rural communities that may have interrupted access to health-care services and dental products such as dentifrices and mouth washes due to various factors; availability and affordability being the most important.

  8. Demand-based maintenance and operators support based on process models; Behovsstyrt underhaall och operatoersstoed baserat paa process modeller

    Energy Technology Data Exchange (ETDEWEB)

    Dahlquist, Erik; Widarsson, Bjoern; Tomas-Aparicio, Elena

    2012-02-15

    There is a strong demand for systems that can give early warnings on upcoming problems in process performance or sensor measurements. In this project we have developed and implemented such a system on-line. The goal with the system is to give warnings about both faults needing urgent actions, as well giving advice on roughly when service may be needed for specific functions. The use of process simulation models on-line can offer a significant tool for operators and process engineers to analyse the performance of the process and make the most correct and fastest decision when problems arise. In this project physical simulation models are used in combination with decision support tools. By using a physical model it is possible to compare the measured data to the data obtained from the simulation and give these deviations as input to a decision support tool with Bayesian Networks (BN) that will result in information about the probability for wrong measurement in the instruments, process problems and maintenance needs. The application has been implemented in a CFB boiler at Maelarenergi AB. After tuning the model the system has been used online during September - October 2010 and May - October 2011, showing that the system is working on-line with respect to running the simulation model but with batch runs with respect to the BN. Examples have been made for several variables where trends of the deviation between simulation results and measured data have been used as input to a BN, where the probability for different faults has been calculated. Combustion up in the separator/cyclones has been detected several times, problems with fuel feed on both sides of the boiler as well. A moisture sensor not functioning as it should and suspected malfunctioning temperature meters as well. Deeper investigations of the true cause of problems have been used as input to tune the BN

  9. Maintenance methods

    International Nuclear Information System (INIS)

    Sanchis, H.; Aucher, P.

    1990-01-01

    The maintenance method applied at the Hague is summarized. The method was developed in order to solve problems relating to: the different specialist fields, the need for homogeneity in the maintenance work, the equipment diversity, the increase of the materials used at the Hague's new facilities. The aim of the method is to create a knowhow formalism, to facilitate maintenance, to ensure the running of the operations and to improve the estimation of the maintenance cost. One of the method's difficulties is the demonstration of the profitability of the maintenance operations [fr

  10. EXPERIMENTAL VALIDATION FOR THE TRAINING METHOD AND MATHEMATICAL MODEL OF THE PILOT SKILL FORMATION IN MAINTENANCE OF ATTITUDE ORIENTATION

    Directory of Open Access Journals (Sweden)

    Maksim BARABANOV

    2017-12-01

    Full Text Available In order to overcome the drawbacks in artificial horizon indicator (HI of inside-in type (a view from an aircraft (A/C, where pilots produce mistakes in maintenance of attitude orientation most of all, the authors offer a novel training method. The method is based on the hypothesis that the manipulative ability of a human visual system can be trained. A mathematical model for the data accumulation during the corresponding training procedure has been proposed. Construction, design and results of the model evaluation are presented in the article. The experimental results revealed the increase of the probability of faultless operation by the test group of up to 0,892, whereas the faultless operation probability of a control group was 0,726. Thus, the trainee-students have statistically increased the reliability for the maintenance of attitude orientation thanks to the proposed method, and the hypothesis was confirmed.

  11. Problems in maintenance of herd health associated with acid forming emissions

    International Nuclear Information System (INIS)

    Kostuch, M.

    1992-01-01

    The effects of sour gas plant emissions on dairy herds are described. A veterinarian establishing a practice in Rocky Mountain House, Alberta, found that dairy herds in that area suffered from a disproportionately higher occurrence of health problems than Minnesota herds with similar types of management. These problems are postulated to result from acid-forming emissions from two large sour gas plants in the area (the Ram River and Gulf Strachan plants). Health problems found in dairy cattle in the Rocky Mountain House area were: unthriftiness, increased susceptibility to infectious diseases, reproductive problems, and 'downer' animals (cows unable to stand up unassisted). Problems related to the reproductive organs were the most apparent. Clinical observations of problems in dairy herds are described. Since the levels of emissions from the plants have decreased, incidence of problems in dairy herds has also decreased. 1 ref., 2 figs

  12. Genetic information: Special or not? Responses from focus groups with members of a health maintenance organization.

    Science.gov (United States)

    Diergaarde, Brenda; Bowen, Deborah J; Ludman, Evette J; Culver, Julie O; Press, Nancy; Burke, Wylie

    2007-03-15

    Genetic information is used increasingly in health care. Some experts have argued that genetic information is qualitatively different from other medical information and, therefore, raises unique social issues. This view, called "genetic exceptionalism," has importantly influenced recent policy efforts. Others have argued that genetic information is like other medical information and that treating it differently may actually result in unintended disparities. Little is known about how the general public views genetic information. To identify opinions about implications of genetic and other medical information among the general population, we conducted a series of focus groups in Seattle, WA. Participants were women and men between ages 18 and 74, living within 30 miles of Seattle and members of the Group Health Cooperative. A structured discussion guide was used to ensure coverage of all predetermined topics. Sessions lasted approximately 2 hr; were audio taped and transcribed. The transcripts formed the basis of the current analysis. Key findings included the theme that genetic information was much like other medical information and that all sensitive medical information should be well protected. Personal choice (i.e., the right to choose whether to know health risk information and to control who else knows) was reported to be of crucial importance. Participants had an understanding of the tensions involved in protecting privacy versus sharing medical information to help another person. These data may guide future research and policy concerning the use and protection of medical information, including genetic information. (c) 2007 Wiley-Liss, Inc.

  13. Development of hardware system using temperature and vibration maintenance models integration concepts for conventional machines monitoring: A case study

    OpenAIRE

    Adeyeri, Michael Kanisuru; Mpofu, Khumbulani; Kareem, Buliaminu

    2016-01-01

    This article describes the integration of temperature and vibration models for maintenance monitoring of conventional machinery parts in which their optimal andbest functionalities are affected by abnormal changes in temperature and vibration values thereby resulting in machine failures, machines breakdown, poor quality of products, inability to meeting customers' demand, poor inventory control and just to mention a few. The work entails the use of temperature and vibration sensors as monitor...

  14. 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

  15. Challenges in economic modeling of anticancer therapies: an example of modeling the survival benefit of olaparib maintenance therapy for patients with BRCA-mutated platinum-sensitive relapsed ovarian cancer.

    Science.gov (United States)

    Hettle, Robert; Posnett, John; Borrill, John

    2015-01-01

    The aim of this paper is to describe a four health-state, semi-Markov model structure with health states defined by initiation of subsequent treatment, designed to make best possible use of the data available from a phase 2 clinical trial. The approach is illustrated using data from a sub-group of patients enrolled in a phase 2 clinical trial of olaparib maintenance therapy in patients with platinum-sensitive relapsed ovarian cancer and a BRCA mutation (NCT00753545). A semi-Markov model was developed with four health states: progression-free survival (PFS), first subsequent treatment (FST), second subsequent treatment (SST), and death. Transition probabilities were estimated by fitting survival curves to trial data for time from randomization to FST, time from FST to SST, and time from SST to death. Survival projections generated by the model are broadly consistent with the outcomes observed in the clinical trial. However, limitations of the trial data (small sample size, immaturity of the PFS and overall survival [OS] end-points, and treatment switching) create uncertainty in estimates of survival. The model framework offers a promising approach to evaluating cost-effectiveness of a maintenance therapy for patients with cancer, which may be generalizable to other chronic diseases.

  16. Suncor maintenance and reliability

    Energy Technology Data Exchange (ETDEWEB)

    Little, S. [Suncor Energy, Calgary, AB (Canada)

    2006-07-01

    Fleet maintenance and reliability at Suncor Energy was discussed in this presentation, with reference to Suncor Energy's primary and support equipment fleets. This paper also discussed Suncor Energy's maintenance and reliability standard involving people, processes and technology. An organizational maturity chart that graphed organizational learning against organizational performance was illustrated. The presentation also reviewed the maintenance and reliability framework; maintenance reliability model; the process overview of the maintenance and reliability standard; a process flow chart of maintenance strategies and programs; and an asset reliability improvement process flow chart. An example of an improvement initiative was included, with reference to a shovel reliability review; a dipper trip reliability investigation; bucket related failures by type and frequency; root cause analysis of the reliability process; and additional actions taken. Last, the presentation provided a graph of the results of the improvement initiative and presented the key lessons learned. tabs., figs.

  17. PRISMA: Program of Research to Integrate the Services for the Maintenance of Autonomy. A system-level integration model in Quebec

    Directory of Open Access Journals (Sweden)

    Margaret MacAdam

    2015-09-01

    Full Text Available The Program of Research to Integrate the Services for the Maintenance of Autonomy (PRISMA began in Quebec in 1999. Evaluation results indicated that the PRISMA Project improved the system of care for the frail elderly at no additional cost. In 2001, the Quebec Ministry of Health and Social Services made implementing the six features of the PRISMA approach a province-wide goal in the programme now known as RSIPA (French acronym. Extensive Province-wide progress has been made since then, but ongoing challenges include reducing unmet need for case management and home care services, creating incentives for increased physician participation in care planning and improving the computerized client chart, among others. PRISMA is the only evaluated international model of a coordination approach to integration and one of the few, if not the only, integration model to have been adopted at the system level by policy-makers.

  18. Health maintenance in school-aged children: Part I. History, physical examination, screening, and immunizations.

    Science.gov (United States)

    Riley, Margaret; Locke, Amy B; Skye, Eric P

    2011-03-15

    The goals of the well-child examination in school-aged children (kindergarten through early adolescence) are promoting health, detecting disease, and counseling to prevent injury and future health problems. A complete history should address any concerns from the patient and family and screen for lifestyle habits, including diet, physical activity, daily screen time (e.g., television, computer, video games), hours of sleep per night, dental care, and safety habits. School performance can be used for developmental surveillance. A full physical examination should be performed; however, the U.S. Preventive Services Task Force recommends against routine scoliosis screening and testicular examination. Children should be screened for obesity, which is defined as a body mass index at or above the 95th percentile for age and sex, and resources for comprehensive, intensive behavioral interventions should be provided to children with obesity. Although the evidence is mixed regarding screening for hypertension before 18 years of age, many experts recommend checking blood pressure annually beginning at three years of age. The American Academy of Pediatrics recommends vision and hearing screening annually or every two years in school-aged children. There is insufficient evidence to recommend screening for dyslipidemia in children of any age, or screening for depression before 12 years of age. All children should receive at least 400 IU of vitamin D daily, with higher doses indicated in children with vitamin D deficiency. Children who live in areas with inadequate fluoride in the water (less than 0.6 ppm) should receive a daily fluoride supplement. Age-appropriate immunizations should be given, as well as any missed immunizations.

  19. Job analysis of the instrument and control technician position for the nuclear power plant maintenance personnel reliability model

    International Nuclear Information System (INIS)

    Siegel, A.I.; Bartter, W.D.; Federman, P.J.

    1983-08-01

    This report is one of a series that is planned to describe the results of a program undertaken by the Oak Ridge National Laboratory (ORNL) for the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, to define, develop, validate, and disseminate a methodology for the quantitative prediction of human reliability in the conduct of maintenance tasks in nuclear power plants (NPPs). ORNL has subcontracted portions of this effort to Applied Psychological Services, Inc. This report on the job analysis of the Instrument and Control technician (NUREG/CR-3274) and a report on the job analysis of the electrician position (NUREG/CR-3275) comprise a part of the initial efforts of the development phase of this program. With the publication of the job analysis of the electrician position, the series of job analyses reports addressing nuclear power plant maintenance personnel will be complete. Subsequent reports addressing model development and validation are planned

  20. Prevalence of Childhood Obesity among Young Multiethnic Children from a Health Maintenance Organization in Hawaii.

    Science.gov (United States)

    Novotny, Rachel; Oshiro, Caryn Etsuko Shima; Wilkens, Lynne Ross

    2013-02-01

    Pacific Islander, Asian, and mixed-ethnicity children are not described in national nutrition and health surveys. Data on BMI values of 4608 5- to 8-year-old children available from Kaiser Permanente Hawaii electronic medical records in 2010 were analyzed for prevalence of overweight and obesity and for ethnic differences in BMI and risk for overweight and obesity, controlling for age, sex, neighborhood education level, and on a subset (n=2169) that further controlled for maternal education and maternal age. Kaiser Permanente data allow for reporting of multiple ethnicities. Data revealed that 33% of this child population was of mixed ethnic ancestry. Prevalence of overweight and obesity was 32.6% (12.9% overweight and 19.7% obese). However, Samoan children and children of Native Hawaiian, Filipino, and mixed ethnic ancestries had higher levels of overweight and obesity than whites or Asians. Higher neighborhood education level, higher maternal education level, and older maternal age were associated with decreased risk of overweight and obesity, except for children whose mothers were between 21 and 30 years old, who had a higher risk for obesity than those whose mothers were under 20 years of age (odds ratio=1.34). Populations of mixed ethnicities in the Pacific region deserve further study related to healthy body size and acculturation to environment and lifestyle.

  1. Newspaper advertising by health maintenance organizations during the reform of healthcare services in Israel.

    Science.gov (United States)

    Reuveni, H; Shvarts, S; Meyer, J; Elhayany, A; Greenberg, D

    2001-06-01

    On 1 January 1995 a new mandatory National Health Insurance Law was enacted in Israel. The new law fostered competition among the four major Israeli healthcare providers (HMOs or sick funds) already operating in the market due to the possibility that an unlimited number of patients and the relative budget share would shift among the HMOs. This led them to launch advertising campaigns to attract new members. To examine newspaper advertising activities during the early stages of healthcare market reform in Israel. Advertising efforts were reviewed during a study period of 24 months (July 1994 to June 1996). Advertisements were analyzed in terms of marketing strategy, costs and quality of information. During the study period 412 newspaper advertisements were collected. The total advertising costs by all HMOs was approximately US$4 million in 1996 prices. Differences were found in marketing strategy, relative advertising costs, contents and priorities among the HMOs. The content of HMOs' newspaper advertising was consistent with their marketing strategy. The messages met the criteria of persuasive advertising in that they cultivated interest in the HMOs but did not provide meaningful information about them. Future developments in this area should include consensus guidelines for advertising activities of HMOs in Israel, instruction concerning the content of messages, and standardization of criteria to report on HMO performance.

  2. A Health Production Model with Endogenous Retirement

    Science.gov (United States)

    Galama, Titus; Kapteyn, Arie; Fonseca, Raquel; Michaud, Pierre-Carl

    2012-01-01

    We formulate a stylized structural model of health, wealth accumulation and retirement decisions building on the human capital framework of health and derive analytic solutions for the time paths of consumption, health, health investment, savings and retirement. We argue that the literature has been unnecessarily restrictive in assuming that health is always at the “optimal” health level. Exploring the properties of corner solutions we find that advances in population health decrease the retirement age, while at the same time individuals retire when their health has deteriorated. This potentially explains why retirees point to deteriorating health as an important reason for early retirement, while retirement ages have continued to fall in the developed world, despite continued improvements in population health and mortality. In our model, workers with higher human capital invest more in health and because they stay healthier retire later than those with lower human capital whose health deteriorates faster. PMID:22888062

  3. Organizational Culture Influence on Total Productive Maintenance (TPM) and Operational Performance Using RASCH Model Analysis

    OpenAIRE

    Mohd Asaad, Mohd Norhasni; Yusoff, Rushami Zien

    2013-01-01

    Abstract. Market globalization, competitive product and services, high economic crises are the most critical factors that influence the success of the manufacturing companies in global market. Therefore it is critical to the manufacturing companies to be efficient in production and lean tool may used to achieve that.  The most frequently used is the Total Preventive Maintenance (TPM), even though there are many studies have been conducted in relation to the TPM but there is limited research i...

  4. The impact of preventive maintenance practices on manufacturing performance: A proposed model for SMEs in Malaysia

    Science.gov (United States)

    Lazim, Halim Mad; Taib, Che Azlan; Lamsali, Hendrik; Saleh, Mohamed Najib; Subramaniam, Chandrakantan

    2016-08-01

    Preventive maintenance (PM) plays important role to avoid or mitigate potential stoppages and disruptions of equipment or machinery from occurring in daily operations. PM emphasized total employee involvement and it is important for companies as well as Small and Medium Sized Enterprises (SMEs). SME sectors contribution to the Malaysian economy makes up 95% of the total manufacturers, however PM remain relatively lacking. The ability, reliability and effective maintenance management is highly important in order to achieve desired manufacturing performance. Therefore, organizational capability in planning, controlling, implementing and monitoring PM activities is important. Furthermore, empirical evidence on the potential impact of PM practices towards manufacturing performance with organizational capability as a moderating effect is still limited and indecisive. Henceforth, this paper aims to explore and investigate potential relationships between PM practices and manufacturing performance moderated by organizational capability in the contact of Malaysian SMEs in the manufacturing sector. Correspondently, the study intends to propose a new research framework and hypotheses to examine the abovementioned relationships. The proposed framework includes PM team, PM strategy and planned maintenance as the determinants, while organizational capability serves as the moderating variable. Manufacturing performance will be viewed in terms of innovation and financial factors. Proposed research direction and conclusion are discussed at the end of the study.

  5. [Maintenance and health promotion of adolescent--pledge of sustainable development of society and state (current status of the issue)].

    Science.gov (United States)

    Baranov, A A; Namazova-Baranova, L S; Il'in, A G

    2014-01-01

    The article presents submitted data of population dynamics of adolescent (10-17 years old) in Russian Federation over the period of 1995-2012 In the presence of reduction by 8.2 million of adolescent population the top-priority task of adolescent health and life maintenance was declared. The article deals with physical growth and development statistics of schoolchildren of 15-19 years old: as opposed to peers of 80-es increase of length, body weight and circumference of chest as well as reduction of muscle strength is observed. On the ground of the data analysis of authoritative statistical reporting the increase of morbidity rate by factor of 1.4 was detected over the last 10 years. It has been established that the true morbidity level is above the authoritative by the factor of 1.5. The number of adolescent at the age of 10-15 referred to 1st and 2nd health groups decreased almost on 20%, at the same time pathological processes become chronic. The reproductive and mental health of adolescent at the age of 15-17 years was analyzed over the last 10 years. The rate of mental health disorders in adolescent living in country is more than in the peers living in cities by the factor of 1.2-1.4. The rate of period disorders, salpingitis and oothecitis increased in girls under 10 years and ones at the age of 15-17. The rate and structure of child disability was analyzed. It was fixed that leading causes of adolescent disability are mental disorders, diseases of nervous system, congenital anomalies. The most commonly encountered seed of physical dysfunction is capacity to study. It is demonstrated that there is misreporting on both child disability in totally and adolescent disability in Russian Federation. After the analysis of particular provisions of legislation concerning medical and social issues of child disability the week points were detected. The morbidity rate of adolescent was studied: primary cause of death in adolescent is extrinsic factor (more than 70%), the

  6. Application of T2 Control Charts and Hidden Markov Models in Condition-Based Maintenance at Thermoelectric Power Plants

    Directory of Open Access Journals (Sweden)

    Emilija Kisić

    2015-01-01

    Full Text Available An innovative approach to condition-based maintenance of coal grinding subsystems at thermoelectric power plants is proposed in the paper. Coal mill grinding tables become worn over time and need to be replaced through time-based maintenance, after a certain number of service hours. At times such replacement is necessary earlier or later than prescribed, depending on the quality of the coal and of the grinding table itself. Considerable financial losses are incurred when the entire coal grinding subsystem is shut down and the grinding table found to not actually require replacement. The only way to determine whether replacement is necessary is to shut down and open the entire subsystem for visual inspection. The proposed algorithm supports condition-based maintenance and involves the application of T2 control charts to distinct acoustic signal parameters in the frequency domain and the construction of Hidden Markov Models whose observations are coded samples from the control charts. In the present research, the acoustic signals were collected by coal mill monitoring at the thermoelectric power plant “Kostolac” in Serbia. The proposed approach provides information about the current condition of the grinding table.

  7. The Smoker’s Health Project: A self-determination theory intervention to facilitate maintenance of tobacco abstinence

    Science.gov (United States)

    Williams, Geoffrey C.; Patrick, Heather; Niemiec, Christopher P.; Ryan, Richard M.; Deci, Edward L.; Lavigne, Holly McGregor

    2011-01-01

    A previous randomized clinical trial based on self-determination theory (SDT) and consistent with the Public Health Service (PHS) Guideline for Treating Tobacco Use and Dependence demonstrated that an intensive intervention could change autonomous self-regulation and perceived competence which in part facilitated long-term tobacco abstinence. The current article describes a pragmatic comparative effectiveness trial of three SDT-based intensive tobacco-dependence interventions. Eligible participants are randomized to one of three treatment conditions designed to facilitate long-term maintenance of tobacco abstinence, namely, Community Care (CC), which includes the 6-month SDT-based intervention previously shown to promote autonomous self-regulation, perceived competence, medication use, and tobacco abstinence; Extended Need Support (ENS), which extends the 6-month SDT-based intervention to 12 months and trains an important other to provide support for smokers’ basic psychological needs; and Harm Reduction (HR), which provides extended need support and recommends medication use for participants who do not want to stop smoking completely within 30 days but who are willing to reduce their cigarette use by half. The primary outcome is 12-month prolonged abstinence from tobacco, which is assessed one year following termination of treatment (two years post-randomization). Secondary outcomes include 7- and 30-day point prevalence tobacco abstinence, number of days using smoking-cessation medication, change in autonomous self-regulation and perceived competence, and perceived need support from important others. PMID:21382516

  8. [Maintenance of exclusive breastfeeding after three months postpartum: An experience in a health department of a Valencian Community].

    Science.gov (United States)

    Vila-Candel, Rafael; Soriano-Vidal, Francisco J; Murillo-Llorente, Mayte; Pérez-Bermejo, Marcelino; Castro-Sánchez, Enrique

    2018-02-14

    To investigate the prevalence of EBF at 3-months postpartum, and the early factors for discontinuation. Observational, retrospective study. Health department of La Ribera, Valencia, Spain. Newborns between December 2012 to January 2017. Pregnant women were interviewed at postpartum and at 3 months regarding variables associated with breastfeeding initiation and continuation, matched with socio-demographic and obstetric-neonatal information. Prevalence of breastfeeding at discharge and exclusive breastfeeding at 3 months. Reasons for interrupt exclusive breastfeeding. Chi-square determination between qualitative variables. One thousand three hundred and thirty-eighth women were recruited. EBF at discharge was 68.2% (913) and at 3 months 46.7% (625). EBF duration was 68.7±32.7 days (95% CI: 66.9-71.2). We found statistically significant differences between the type of breastfeeding and the variables, year of study, country of origin and parity (P<0.001, P=0.005 and P=0.05 respectively). Hypogalactia (21.8%) and lower than recommended increase in newborn weight gain (14.9%) were most frequent factors for discontinuation. The prevalence of EBF at 3 months is low compared to other similar studies, although we see an upward trend. Belief in hypogalactia influenced the maintenance of exclusive breastfeeding. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  9. Union-related correlates of employee referrals to an occupational alcoholism project in a health maintenance organization.

    Science.gov (United States)

    Putnam, S L; Stout, R L

    1982-03-01

    A number of union-related factors, including the degree of unionization and the skill level of the work force, the quality of union-management relations, the extent of union involvement in program development, as well as the provision of supervisory training, have been found to be important in explaining occupational alcoholism program outcome. This study attempted to determine the relationship of such factors to an unusual measure of program outcome, employee referrals to the treatment component of an occupational alcoholism project housed in the counseling department of a health maintenance organization. Multiple-regression techniques were used, with data collected for unionized companies that adopted formal, written employee assistance program (EAP) policies and those that did not. The adoption of an EAP policy seems more important than any other factor in predicting referrals to treatment, In unionized companies without policies, the union-related factors bear no relationship to referrals, while in unionized companies with policies, these variables, particularly the quality of union-management relations, are strong predictors. Supervisory training has only a modest positive effect on referrals. The adoption of an employee assistance policy itself was found to be crucial to program outcome, measured by increased chances of referrals.

  10. Preventative Maintenance.

    Science.gov (United States)

    Migliorino, James

    Boards of education must be convinced that spending money up front for preventive maintenance will, in the long run, save districts' tax dollars. A good program of preventive maintenance can minimize disruption of service; reduce repair costs, energy consumption, and overtime; improve labor productivity and system equipment reliability; handle…

  11. Assessing cognitive processes related to insomnia: A review and measurement guide for Harvey's cognitive model for the maintenance of insomnia.

    Science.gov (United States)

    Hiller, Rachel M; Johnston, Anna; Dohnt, Hayley; Lovato, Nicole; Gradisar, Michael

    2015-10-01

    Cognitive processes play an important role in the maintenance, and treatment of sleep difficulties, including insomnia. In 2002, a comprehensive model was proposed by Harvey. Since its inception the model has received >300 citations, and provided researchers and clinicians with a framework for understanding and treating insomnia. The aim of this review is two-fold. First, we review the current literature investigating each factor proposed in Harvey's cognitive model of insomnia. Second, we summarise the psychometric properties of key measures used to assess the model's factors and mechanisms. From these aims, we demonstrate both strengths and limitations of the current knowledge of appropriate measurements associated with the model. This review aims to stimulate and guide future research in this area; and provide an understanding of the resources available to measure, target, and resolve cognitive factors that may maintain chronic insomnia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Maintenance of scientific instruments

    International Nuclear Information System (INIS)

    Lucero, E.

    1986-01-01

    During the last years Colombia has increased the use of nuclear techniques, instruments and equipment in ambitious health programs, as well as in research centers, industry and education; this has resulted in numerous maintenance problems. As an alternative solution IAN has established a Central Maintenance Laboratory for nuclear instruments within an International Atomic Energy Agency program for eight Latin American and nine Asian Countries. Established strategies and some results are detailed in this writing

  13. Limited agreement exists between rationale and practice in athletes' supplement use for maintenance of health: a retrospective study

    Directory of Open Access Journals (Sweden)

    Mazanov Jason

    2007-10-01

    Full Text Available Abstract Background The widespread use of nutritional supplements among athletes is poorly understood. The prevalence of supplement intake and users' knowledge have been researched independently leading to useful, but disconnected, information on supplement use. Methods The 'UK Sport 2005 Drug Free Survey' data (n = 874 were re-analysed using association [χ2] and 'strength of association' tests [φ], to discover observed incongruencies between self-reported supplement use and the underlying motives. Results are given for test pairs between 'motive for use' [doctor's advice, avoiding sickness, overcoming injuries and enhancement of diet] and each supplement used and these were categorized as strong (φ > .7, intermediate (7 φ > .3 and weak (φ Results The use of selected supplements varied widely as follows: multivitamin (72.7%, vitamin C (70.4%, echinacea (30.8%, iron (29.8%, magnesium (11.0% and ginseng (8.3%. Associations with motive were found in 8 of the 10 test pairs which were expected from literature precedents, however only weak associations exist. Of these, four were associated with avoidance of sickness [iron (χ2 = 11.94, p χ2 = 6.43, p φ = .11, p = .011, vitamin C (χ2 = 54.67, p φ = .32, p χ2 = 40.34, p φ = .28, p χ2 = 7.64, p = .006; φ = .12, p = .006 and multivitamin (χ2 = 9.103, p = .003; φ = .13, p = .003; overcoming injuries with magnesium (χ2 = 6.99, p = .008; φ = .11, p = .008; doctors' advice and iron (χ2 = 35.00, p φ = .25, p = .001. Conclusion These results suggest a lack of understanding regarding supplements and health maintenance, except for vitamin C and echinacea. Furthermore, supplement use is apparently independent of physicians/dieticians' advice, except for iron. This may suggest a widespread circumvention of expert advice in the growing area of supplement use and therefore should be addressed to underscore potential health risks.

  14. Modeling Per Capita State Health Expenditure Variat...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Modeling Per Capita State Health Expenditure Variation State-Level Characteristics Matter, published in Volume 3, Issue 4, of the Medicare and Medicaid Research...

  15. The role of information in a lifetime process - a model of weight maintenance by women over long time periods

    Directory of Open Access Journals (Sweden)

    Judit Bar-Ilan

    2006-01-01

    Full Text Available Introduction. This paper proposes a model of information behaviour of women during their life-long struggle to maintain normal weight. Method. The model is integrative and contextual, built on existing models in information science and several other disciplines, and the life stories of about fifty Israeli women aged 25-55 and interviews with professionals. Analysis. The life stories of the participating women were analyzed qualitatively, major themes and phases were identified. Results. Weight loss and/or maintenance behaviour is a lifetime process in which distinctive stages were identified. In most cases the weight gain - weight loss - maintenance cycle is a recurring cycle. Information is a major resource during the process: several roles of information were defined: enabling, motivating, reinforcing, providing background information related to weight problems and creating the internal cognitive schema related to food and weight. Information behaviour and the roles of information vary with the different stages. Information needs are also influenced by the specific stage of the process. Information gathered at previous cycles is reused, and information gained through previous experience effects behaviour in the current cycle. Conclusion. The model has both theoretical and practical implications.

  16. AVIATION SAFETY CULTURE MEASUREMENT MODEL FIT VALIDATION OF A SURVEY FOR THE AVIATION MAINTENANCE REPAIR ORGANIZATIONS

    OpenAIRE

    Vahap ÖNEN

    2017-01-01

    It is believed that safety is the major issue for the aviation industry. According to Boeing Study %15 of the fatal accidents are incurred by maintenance sources related. On the other hand, from the last ten years safety management system which firstly introduced by ICAO became popular in the aviation industry. In the beginning, enforcement by ICAO Annex 19 then following it consequtively by EASA’s regulation, at the same time issued many advisory circulars by FAA that SMS entried in force an...

  17. User Delay Cost Model and Facilities Maintenance Cost Model for a Terminal Control Area : Volume 1. Model Formulation and Demonstration

    Science.gov (United States)

    1978-05-01

    The User Delay Cost Model (UDCM) is a Monte Carlo computer simulation of essential aspects of Terminal Control Area (TCA) air traffic movements that would be affected by facility outages. The model can also evaluate delay effects due to other factors...

  18. Comparison of health-related quality of life of children during maintenance therapy with acute lymphoblastic leukemia versus siblings and healthy children in India.

    Science.gov (United States)

    Bansal, Minakshi; Sharma, Kamlesh K; Vatsa, Manju; Bakhshi, Sameer

    2013-05-01

    Data on quality of life (QOL) specifically in maintenance therapy of acute lymphoblastic leukemia (ALL) are minimal. This study was done to assess various items listed in domains of QOL (physical, emotional, social and school health domains) of children with ALL during maintenance therapy, and compare the same with those of their siblings and other healthy children. Forty children on maintenance therapy of ALL, 40 siblings and 40 healthy children were assessed for QOL by child self-report using PedsQL 4.0 Generic Core in the local language. Means were computed and compared for each domain with one-way analysis of variance (ANOVA), wherein higher values reflected better QOL. Overall QOL of children with ALL in maintenance therapy (77.16 ± 10.98) was significantly poorer than that of siblings (93.56 ± 4.41) and healthy children (93.02 ± 3.76) (p fear, anger, sleeping problems) among children with ALL. In the social health domain, children with ALL reported difficulty in maintaining friendships and competing. QOL of siblings was as good as that of healthy children in physical, social and school health domains, but they had increased emotional problems such as anger and sadness. Healthy children reported significantly higher future worries and bullying than children with ALL and siblings. This study validated that the QOL of children with ALL during maintenance therapy was significantly poorer than that of siblings and healthy children. The study identified various items in each domain of QOL that were affected in these children, and thus would assist in guiding healthcare professionals to focus on these specific items so as to improve their overall QOL.

  19. Reinforcing Spirals Model: Conceptualizing the Relationship Between Media Content Exposure and the Development and Maintenance of Attitudes

    Science.gov (United States)

    Slater, Michael D.

    2014-01-01

    The Reinforcing Spirals Model (RSM, Citation Withheld) has two primary purposes. First, the RSM provides a general framework for conceptualizing media use as part of a dynamic, endogenous process combining selective exposure and media effects that may be drawn on by theorists concerned with a variety of social processes and effects. Second, the RSM utilizes a systems-theory perspective to describe how patterns of mediated and interpersonal communication contribute to the development and maintenance of social identities and ideology as well as more transient attitudes and related behaviors, and how those outcomes may influence subsequent media use. The RSM suggests contingencies that may lead to homeostasis or encourage certain individuals or groups to extreme polarization of such attitudes. In addition, the RSM proposes social cognitive mechanisms that may be responsible for attitude maintenance and reinforcement. This article discusses empirical progress in testing the model, addresses misconceptions that have arisen, and provides elaborated illustrations of the model. The article also identifies potentially fruitful directions for further conceptual development and empirical testing of the RSM. PMID:26366124

  20. Reinforcing Spirals Model: Conceptualizing the Relationship Between Media Content Exposure and the Development and Maintenance of Attitudes.

    Science.gov (United States)

    Slater, Michael D

    2015-07-01

    The Reinforcing Spirals Model (RSM, Citation Withheld) has two primary purposes. First, the RSM provides a general framework for conceptualizing media use as part of a dynamic, endogenous process combining selective exposure and media effects that may be drawn on by theorists concerned with a variety of social processes and effects. Second, the RSM utilizes a systems-theory perspective to describe how patterns of mediated and interpersonal communication contribute to the development and maintenance of social identities and ideology as well as more transient attitudes and related behaviors, and how those outcomes may influence subsequent media use. The RSM suggests contingencies that may lead to homeostasis or encourage certain individuals or groups to extreme polarization of such attitudes. In addition, the RSM proposes social cognitive mechanisms that may be responsible for attitude maintenance and reinforcement. This article discusses empirical progress in testing the model, addresses misconceptions that have arisen, and provides elaborated illustrations of the model. The article also identifies potentially fruitful directions for further conceptual development and empirical testing of the RSM.

  1. Process health management using success tree and empirical model

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Kim, Suyoung [BNF Technology, Daejeon (Korea, Republic of); Sung, Wounkyoung [Korea South-East Power Co. Ltd., Seoul (Korea, Republic of)

    2012-03-15

    Interests on predictive or condition-based maintenance are heightening in power industries. The ultimate goal of the condition-based maintenance is to prioritize and optimize the maintenance resources by taking a reasonable decision-making process depending op plant's conditions. Such decision-making process should be able to not only observe the deviation from a normal state but also determine the severity or impact of the deviation on different levels such as a component, a system, or a plant. In order to achieve this purpose, a Plant Health Index (PHI) monitoring system was developed, which is operational in more than 10 units of large steam turbine cycles in Korea as well as desalination plants in Saudi Arabia as a proto-type demonstration. The PHI monitoring system has capability to detect whether the deviation between a measured and an estimated parameter which is the result of kernel regression using the accumulated operation data and the current plant boundary conditions (referred as an empirical model) is statistically meaningful. This deviation is converted into a certain index considering the margin to set points which are associated with safety. This index is referred as a PHI and the PHIs can be monitored for an individual parameter as well as a component, system, or plant level. In order to organize the PHIs at the component, system, or plant level, a success tree was developed. At the top of the success tree, the PHIs nodes in the middle of the success tree, the PHIs represent the health status of a component or a system. The concept and definition of the PHI, the key methodologies, the architecture of the developed system, and a practical case of using the PHI monitoring system are described in this article.

  2. Process health management using success tree and empirical model

    International Nuclear Information System (INIS)

    Heo, Gyunyoung; Kim, Suyoung; Sung, Wounkyoung

    2012-01-01

    Interests on predictive or condition-based maintenance are heightening in power industries. The ultimate goal of the condition-based maintenance is to prioritize and optimize the maintenance resources by taking a reasonable decision-making process depending op plant's conditions. Such decision-making process should be able to not only observe the deviation from a normal state but also determine the severity or impact of the deviation on different levels such as a component, a system, or a plant. In order to achieve this purpose, a Plant Health Index (PHI) monitoring system was developed, which is operational in more than 10 units of large steam turbine cycles in Korea as well as desalination plants in Saudi Arabia as a proto-type demonstration. The PHI monitoring system has capability to detect whether the deviation between a measured and an estimated parameter which is the result of kernel regression using the accumulated operation data and the current plant boundary conditions (referred as an empirical model) is statistically meaningful. This deviation is converted into a certain index considering the margin to set points which are associated with safety. This index is referred as a PHI and the PHIs can be monitored for an individual parameter as well as a component, system, or plant level. In order to organize the PHIs at the component, system, or plant level, a success tree was developed. At the top of the success tree, the PHIs nodes in the middle of the success tree, the PHIs represent the health status of a component or a system. The concept and definition of the PHI, the key methodologies, the architecture of the developed system, and a practical case of using the PHI monitoring system are described in this article

  3. Multipurpose expert-robot system model for control, diagnosis, maintenance, and repairs at the steam generators of the NPP

    International Nuclear Information System (INIS)

    Popa, I.

    1994-01-01

    The paper presents the model concept for a multipurpose expert-robot system for control, diagnosis, forecast, maintenance, and repairs at the steam generators of CANDU type nuclear power plants. The system has two separate parts: the expert system and the robot (manipulator) system. These parts compose a hierarchic structure with the expert system on the upper level. The expert system has a blackboard architecture, to which tree interfaces with the robot system, with the control system of the NPP and with the methods and techniques of control, maintenance and repairs system of the steam generator are added. Due to complex nature of its activities the expert-robot system model combines the deterministic type reasons with probabilistic, fuzzy, and neural-networks type ones. The information that enter the expert system comes from the robot system, from process, from user, and human expert. The information that enter robot system comes from the expert system, from the human operator (when connected) and from process. Control maintenance and repair operations take place by means of the robot system that can be monitored either directly by the expert system or by the human operator who follows its activity. All these activities are performed in parallel with the adequate information of the expert system directly, by the human operator, about the status parameters and, possibly, operating parameters of the steam generator components. The expert-robot system can work independently, but it can be connected and integrated in the control system of NPP, to take over and develop some of its functions. The activities concerning diagnosis and characterization of the state of steam generator components subsequent to control, as well as the forecast of their future behavior, are performed by means of the expert system. Due to these characteristics the expert-robot system can be used successfully in personnel training activities. (Author)

  4. Maintenance Process Strategic Analysis

    Science.gov (United States)

    Jasiulewicz-Kaczmarek, M.; Stachowiak, A.

    2016-08-01

    The performance and competitiveness of manufacturing companies is dependent on the availability, reliability and productivity of their production facilities. Low productivity, downtime, and poor machine performance is often linked to inadequate plant maintenance, which in turn can lead to reduced production levels, increasing costs, lost market opportunities, and lower profits. These pressures have given firms worldwide the motivation to explore and embrace proactive maintenance strategies over the traditional reactive firefighting methods. The traditional view of maintenance has shifted into one of an overall view that encompasses Overall Equipment Efficiency, Stakeholders Management and Life Cycle assessment. From practical point of view it requires changes in approach to maintenance represented by managers and changes in actions performed within maintenance area. Managers have to understand that maintenance is not only about repairs and conservations of machines and devices, but also actions striving for more efficient resources management and care for safety and health of employees. The purpose of the work is to present strategic analysis based on SWOT analysis to identify the opportunities and strengths of maintenance process, to benefit from them as much as possible, as well as to identify weaknesses and threats, so that they could be eliminated or minimized.

  5. Maintenance Mentor

    National Research Council Canada - National Science Library

    Jacobs, John

    2003-01-01

    Maintenance Mentor (MXM) is a research effort conducted by a joint AFRL/HESR and Northrop Grumman Information Technology team to identify the basic, high-level requirements necessary for improving flight line diagnostic capabilities...

  6. 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.

  7. Job analysis of the electrician position for the nuclear power plant maintenance personnel reliability model

    International Nuclear Information System (INIS)

    Federman, P.J.; Bartter, W.D.; Siegel, A.I.

    1984-02-01

    This report presents the methods, procedures, and results of the fourth and final of a series of job analytic studies which characterize maintenance positions in nuclear power plants. The electrician position is the subject of the present report. The characterization of the electrician position takes the form of detailed information about: (1) the frequency of performing various tasks, (2) the time required for performing each task, (3) the training required for adequate performance of each task, and (4) the perceived consequences resulting from inadequate task performance. Additionally, information is presented about the intellective and the perceptual-motor loading imposed by each task. This information contributes to job design and training requirements derivation as well as to the assessment of human performance reliability in nuclear power plants

  8. 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

  9. 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

  10. Lactitol and the maintenance of normal defecation: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Sjödin, Anders Mikael

    2015-01-01

    that the maintenance of normal defecation is a beneficial physiological effect. A total of 15 human intervention studies were identified as pertinent to the health claim. Twelve studies with various methodological limitations consistently showed that consumption of at least 10 g/day lactitol increases stool frequency......Following an application from DuPont Nutrition BioSciences ApS, submitted pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of the United Kingdom, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific...... substantiation of a health claim related to lactitol and the maintenance of normal defecation. The food constituent that is the subject of the claim is lactitol. The Panel considers that the food constituent lactitol, which is the subject of the claim, is sufficiently characterised. The Panel considers...

  11. Incorrect modeling of the failure process of minimally repaired systems under random conditions: The effect on the maintenance costs

    International Nuclear Information System (INIS)

    Pulcini, Gianpaolo

    2015-01-01

    This note investigates the effect of the incorrect modeling of the failure process of minimally repaired systems that operates under random environmental conditions on the costs of a periodic replacement maintenance. The motivation of this paper is given by a recently published paper, where a wrong formulation of the expected cost for unit time under a periodic replacement policy is obtained. This wrong formulation is due to the incorrect assumption that the intensity function of minimally repaired systems that operate under random conditions has the same functional form as the failure rate of the first failure time. This produced an incorrect optimization of the replacement maintenance. Thus, in this note the conceptual differences between the intensity function and the failure rate of the first failure time are first highlighted. Then, the correct expressions of the expected cost and of the optimal replacement period are provided. Finally, a real application is used to measure how severe can be the economical consequences caused by the incorrect modeling of the failure process.

  12. Modeling the Hybrid Flow Shop Scheduling Problem Followed by an Assembly Stage Considering Aging Effects and Preventive Maintenance Activities

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Hassan Hosseini

    2016-05-01

    Full Text Available Scheduling problem for the hybrid flow shop scheduling problem (HFSP followed by an assembly stage considering aging effects additional preventive and maintenance activities is studied in this paper. In this production system, a number of products of different kinds are produced. Each product is assembled with a set of several parts. The first stage is a hybrid flow shop to produce parts. All machines can process all kinds of parts in this stage but each machine can process only one part at the same time. The second stage is a single assembly machine or a single assembly team of workers. The aim is to schedule the parts on the machines and assembly sequence and also determine when the preventive maintenance activities get done in order to minimize the completion time of all products (makespan. A mathematical modeling is presented and its validation is shown by solving an example in small scale. Since this problem has been proved strongly NP-hard, in order to solve the problem in medium and large scale, four heuristic algorithms is proposed based on the Johnson’s algorithm. The numerical experiments are used to run the mathematical model and evaluate the performance of the proposed algorithms.

  13. Total Productive Maintenance And Role Of Interpretive Structural Modeling And Structural Equation Modeling In Analyzing Barriers In Its Implementation A Literature Review

    Directory of Open Access Journals (Sweden)

    Prasanth S. Poduval

    2015-08-01

    Full Text Available Abstract - The aim of the authors is to present a review of literature of Total Productive Maintenance and the barriers in implementation of Total Productive Maintenance TPM. The paper begins with a brief description of TPM and the barriers in implementation of TPM. Interpretive Structural Modeling ISM and its role in analyzing the barriers in TPM implementation is explained in brief. Applications of ISM in analyzing issues in various fields are highlighted with special emphasis on TPM. The paper moves on to introduction to Structural Equation Modeling SEM and its role in validating ISM in analyzing barriers in implementation of TPM. The paper concludes with a gap analysis from the current literature research that can be carried out and expected outcomes from the proposed research.

  14. Data management in maintenance outsourcing

    International Nuclear Information System (INIS)

    Murthy, D.N.P.; Karim, M.R.; Ahmadi, A.

    2015-01-01

    Most businesses view maintenance as tasks carried out by technicians and the data collected is mostly cost related. There is a growing trend towards outsourcing of maintenance and the data collection issues are not addressed properly in most maintenance service contracts. Effective maintenance management requires proper data management - data collection and analysis for decision-making. This requires a proper framework and when maintenance is outsourced it raises several issues and challenges. The paper develops a framework for data management when maintenance is outsourced and looks at a real case study that highlights the need for proper data management. - Highlights: • Framework for data management in maintenance outsourcing. • Black-box to grey-box approaches for modelling. • Improvements to maintenance decision-making. • Case study to illustrate the approaches and the shortcomings in data collection

  15. An off-line dual maximum resource bin packing model for solving the maintenance problem in the aviation industry

    Directory of Open Access Journals (Sweden)

    George Cristian Gruia

    2013-05-01

    Full Text Available In the aviation industry, propeller motor engines have a lifecycle of several thousand hours of flight and the maintenance is an important part of their lifecycle. The present article considers a multi-resource, priority-based case scheduling problem, which is applied in a Romanian manufacturing company, that repairs and maintains helicopter and airplane engines at a certain quality level imposed by the aviation standards. Given a reduced budget constraint, the management’s goal is to maximize the utilization of their resources (financial, material, space, workers, by maintaining a prior known priority rule. An Off-Line Dual Maximum Resource Bin Packing model, based on a Mixed Integer Programming model is thus presented. The obtained results show an increase with approx. 25% of the Just in Time shipping of the engines to the customers and approx. 12,5% increase in the utilization of the working area.

  16. AN OFF-LINE DUAL MAXIMUM RESOURCE BIN PACKING MODEL FOR SOLVING THE MAINTENANCE PROBLEM IN THE AVIATION INDUSTRY

    Directory of Open Access Journals (Sweden)

    GEORGE CRISTIAN GRUIA

    2013-05-01

    Full Text Available In the aviation industry, propeller motor engines have a lifecycle of several thousand hours of flight and the maintenance is an important part of their lifecycle. The present article considers a multi-resource, priority-based case scheduling problem, which is applied in a Romanian manufacturing company, that repairs and maintains helicopter and airplane engines at a certain quality level imposed by the aviation standards. Given a reduced budget constraint, the management’s goal is to maximize the utilization of their resources (financial, material, space, workers, by maintaining a prior known priority rule. An Off-Line Dual Maximum Resource Bin Packing model, based on a Mixed Integer Programing model is thus presented. The obtained results show an increase with approx. 25% of the Just in Time shipping of the engines to the customers and approx. 12,5% increase in the utilization of the working area.

  17. Framework for ensuring appropriate maintenance of baseline PSA and risk monitor models in a nuclear power plant

    International Nuclear Information System (INIS)

    Vrbanic, I.; Sorman, J.

    2005-01-01

    The necessity of observing both long term and short term risk changes many times imposes the need for a nuclear power plant to have a baseline PSA model to produce an estimate of long term averaged risk and a risk monitor to produce a time-dependent risk curve and/or safety functions status at points in time or over a shorter time period of interest. By nature, a baseline PSA reflects plant systems and operation in terms of average conditions and provides time-invariant quantitative risk metrics. Risk monitor, on the other hand, requires condition-specific modeling to produce a quantitative and/or qualitative estimate of plant's condition-specific risk metrics. While risk monitor is used for computing condition-specific risk metrics over time, a baseline PSA model is needed for variety of other risk oriented applications, such as assessments of proposed design modifications or risk ranking of equipment. Having in mind their importance and roles, it is essential that both models, i.e. baseline PSA model and risk monitor are maintained in the way that they represent, as accurately as practically achievable, the actual plant status (e.g. systems' design and plant's procedures in effect) and its history (e.g. numbers of equipment failures and demands that influence relevant PSA parameters). Paper discusses the requirements for appropriate maintenance of plant's baseline PSA model and risk monitor model and presents the framework for plant's engineering and administrative procedures that would ensure they are met. (author)

  18. Use of Just in Time Maintenance of Reinforced Concrete Bridge Structures based on Real Historical Data Deterioration Models

    Directory of Open Access Journals (Sweden)

    Abu-Tair A.

    2016-01-01

    Full Text Available Concrete is the backbone of any developed economy. Concrete can suffer from a large number of deleterious effects including physical, chemical and biological causes. Large owning bridge structures organizations are facing very serious questions when asking for maintenance budgets. The questions range from needing to justify the need for the work, its urgency, to also have to predict or show the consequences of delayed rehabilitation of a particular structure. There is therefore a need for a probabilistic model that can estimate the range of service lives of bridge populations and also the likelihood of level of deteriorations it can reached for every incremental time interval. A model was developed for such estimation based on statistical data from actual inspection records of a large reinforced concrete bridge portfolio. The method used both deterministic and stochastic methods to predict the service life of a bridge, using these service lives in combination with the just in time (JIT principle of management would enable maintenance managers to justify the need for action and the budgets needed, to intervene at the optimum time in the life of the structure and that of the deterioration. The paper will report on the model which is based on a large database of deterioration records of concrete bridges covering a period of over 60 years and include data from over 400 bridge structures. The paper will also illustrate how the service life model was developed and how these service lives combined with the JIT can be used to effectively allocate resources and use them to keep a major infrastructure asset moving with little disruption to the transport system and its users.

  19. Global Health Innovation Technology Models

    Directory of Open Access Journals (Sweden)

    Kimberly Harding

    2016-04-01

    Full Text Available Chronic technology and business process disparities between High Income, Low Middle Income and Low Income (HIC, LMIC, LIC research collaborators directly prevent the growth of sustainable Global Health innova‐ tion for infectious and rare diseases. There is a need for an Open Source-Open Science Architecture Framework to bridge this divide. We are proposing such a framework for consideration by the Global Health community, by utiliz‐ ing a hybrid approach of integrating agnostic Open Source technology and healthcare interoperability standards and Total Quality Management principles. We will validate this architecture framework through our programme called Project Orchid. Project Orchid is a conceptual Clinical Intelligence Exchange and Virtual Innovation platform utilizing this approach to support clinical innovation efforts for multi-national collaboration that can be locally sustainable for LIC and LMIC research cohorts. The goal is to enable LIC and LMIC research organizations to acceler‐ ate their clinical trial process maturity in the field of drug discovery, population health innovation initiatives and public domain knowledge networks. When sponsored, this concept will be tested by 12 confirmed clinical research and public health organizations in six countries. The potential impact of this platform is reduced drug discovery and public health innovation lag time and improved clinical trial interventions, due to reliable clinical intelligence and bio-surveillance across all phases of the clinical innovation process.

  20. Modeling Medical Services with Mobile Health Applications

    Directory of Open Access Journals (Sweden)

    Zhenfei Wang

    2018-01-01

    Full Text Available The rapid development of mobile health technology (m-Health provides unprecedented opportunities for improving health services. As the bridge between doctors and patients, mobile health applications enable patients to communicate with doctors through their smartphones, which is becoming more and more popular among people. To evaluate the influence of m-Health applications on the medical service market, we propose a medical service equilibrium model. The model can balance the supply of doctors and demand of patients and reflect possible options for both doctors and patients with or without m-Health applications in the medical service market. In the meantime, we analyze the behavior of patients and the activities of doctors to minimize patients’ full costs of healthcare and doctors’ futility. Then, we provide a resolution algorithm through mathematical reasoning. Lastly, based on artificially generated dataset, experiments are conducted to evaluate the medical services of m-Health applications.

  1. Presenting a model of repair and preventing maintenance of Bushehr nuclear power plants analyzing the data of similar nuclear power plants

    International Nuclear Information System (INIS)

    Parikhan, Hammidreza

    1997-01-01

    Due to the increase application of nuclear energy for producing electricity, special attention must be paid to their maintenance activities in general and preventive maintenance in particular. It has been shown that a well established preventive maintenance programme will enhance the reliability and availability of nuclear power plants. A model of preventive maintenance for Buhehr nuclear power plant which is due to be completed by 2001 is developed. The prescribed model is based on past experiences of VVER nuclear power plants around the world. The utilized data is provided by International Atomic Energy Agency (IAEA) in Vienna, Austria. The data and past experiences reveal such important information as availability, energy loss, types of failures, duration of failure, etc. A strategy for designing a database is established. These data are then analyzed by statistical methods such as Pareto analysis, t-test, K-S test, analysis of variance, etc. The results of our analysis reveal important information in regard to establishment of a well-defined preventive maintenance programme in Buhshehr nuclear power plant. The results show that certain equipment such turbo-generator and control-rods play an important role in the maintenance of a VVER nuclear power plant. Other findings are discussed in great detail

  2. Multi-metric model-based structural health monitoring

    Science.gov (United States)

    Jo, Hongki; Spencer, B. F.

    2014-04-01

    ABSTRACT The inspection and maintenance of bridges of all types is critical to the public safety and often critical to the economy of a region. Recent advanced sensor technologies provide accurate and easy-to-deploy means for structural health monitoring and, if the critical locations are known a priori, can be monitored by direct measurements. However, for today's complex civil infrastructure, the critical locations are numerous and often difficult to identify. This paper presents an innovative framework for structural monitoring at arbitrary locations on the structure combining computational models and limited physical sensor information. The use of multi-metric measurements is advocated to improve the accuracy of the approach. A numerical example is provided to illustrate the proposed hybrid monitoring framework, particularly focusing on fatigue life assessment of steel structures.

  3. Modeling Health Care Expenditures and Use.

    Science.gov (United States)

    Deb, Partha; Norton, Edward C

    2018-04-01

    Health care expenditures and use are challenging to model because these dependent variables typically have distributions that are skewed with a large mass at zero. In this article, we describe estimation and interpretation of the effects of a natural experiment using two classes of nonlinear statistical models: one for health care expenditures and the other for counts of health care use. We extend prior analyses to test the effect of the ACA's young adult expansion on three different outcomes: total health care expenditures, office-based visits, and emergency department visits. Modeling the outcomes with a two-part or hurdle model, instead of a single-equation model, reveals that the ACA policy increased the number of office-based visits but decreased emergency department visits and overall spending.

  4. Game Maturity Model for Health Care.

    Science.gov (United States)

    de Boer, Jan C; Adriani, Paul; van Houwelingen, Jan Willem; Geerts, A

    2016-04-01

    This article introduces the Game Maturity Model for the healthcare industry as an extension to the general Game Maturity Model and describes the usage by two case studies of applied health games. The Game Maturity Model for healthcare provides a practical and value-adding method to assess existing games and to determine strategic considerations for application of applied health games. Our forecast is that within 5 years the use and development of applied games will have a role in our daily lives and the way we organize health care that will be similar to the role social media has today.

  5. ATP Maintenance via Two Types of ATP Regulators Mitigates Pathological Phenotypes in Mouse Models of Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Masaki Nakano

    2017-08-01

    Full Text Available Parkinson's disease is assumed to be caused by mitochondrial dysfunction in the affected dopaminergic neurons in the brain. We have recently created small chemicals, KUSs (Kyoto University Substances, which can reduce cellular ATP consumption. By contrast, agonistic ligands of ERRs (estrogen receptor-related receptors are expected to raise cellular ATP levels via enhancing ATP production. Here, we show that esculetin functions as an ERR agonist, and its addition to culture media enhances glycolysis and mitochondrial respiration, leading to elevated cellular ATP levels. Subsequently, we show the neuroprotective efficacies of KUSs, esculetin, and GSK4716 (an ERRγ agonist against cell death in Parkinson's disease models. In the surviving neurons, ATP levels and expression levels of α-synuclein and CHOP (an ER stress-mediated cell death executor were all rectified. We propose that maintenance of ATP levels, by inhibiting ATP consumption or enhancing ATP production, or both, would be a promising therapeutic strategy for Parkinson's disease.

  6. Modeling and Control of Industrial ROV's for Semi-Autonomous Subsea Maintenance Services

    DEFF Research Database (Denmark)

    Mai, Christian; Pedersen, Simon; Hansen, Leif

    2017-01-01

    as improving the inspection quality. This study examines an industrial ROV, where the investigations include modeling of a real industrial prototype, which is then linearized and used for Linear Quadratic Regulator (LQR) development. The results are validated both based on non-linear model simulations...

  7. A Bayesian network based approach for integration of condition-based maintenance in strategic offshore wind farm O&M simulation models

    DEFF Research Database (Denmark)

    Nielsen, Jannie Sønderkær; Sørensen, John Dalsgaard; Sperstad, Iver Bakken

    2018-01-01

    In the overall decision problem regarding optimization of operation and maintenance (O&M) for offshore wind farms, there are many approaches for solving parts of the overall decision problem. Simulation-based strategy models accurately capture system effects related to logistics, but model...... to generate failures and CBM tasks. An example considering CBM for wind turbine blades demonstrates the feasibility of the approach....

  8. The Union Health Center: a working model of clinical care linked to preventive occupational health services.

    Science.gov (United States)

    Herbert, R; Plattus, B; Kellogg, L; Luo, J; Marcus, M; Mascolo, A; Landrigan, P J

    1997-03-01

    As health care provision in the United States shifts to primary care settings, it is vital that new models of occupational health services be developed that link clinical care to prevention. The model program described in this paper was developed at the Union Health Center (UHC), a comprehensive health care center supported by the International Ladies Garment Workers Union (now the Union of Needletrades, Industrial and Textile Employees) serving a population of approximately 50,000 primarily minority, female garment workers in New York City. The objective of this paper is to describe a model occupational medicine program in a union-based comprehensive health center linking accessible clinical care with primary and secondary disease prevention efforts. To assess the presence of symptoms suggestive of occupational disease, a health status questionnaire was administered to female workers attending the UHC for routine health maintenance. Based on the results of this survey, an occupational medicine clinic was developed that integrated direct clinical care with worker and employer education and workplace hazard abatement. To assess the success of this new approach, selected cases of sentinel health events were tracked and a chart review was conducted after 3 years of clinic operation. Prior to initiation of the occupational medicine clinic, 64% (648) of the workers surveyed reported symptoms indicative of occupational illnesses. However, only 42 (4%) reported having been told by a physician that they had an occupational illness and only 4 (.4%) reported having field a workers' compensation claim for an occupational disease. In the occupational medicine clinic established at the UHC, a health and safety specialist acts as a case manager, coordinating worker and employer education as well as workplace hazard abatement focused on disease prevention, ensuring that every case of occupational disease is treated as a potential sentinel health event. As examples of the success

  9. Heritage house maintenance using 3D city model application domain extension approach

    DEFF Research Database (Denmark)

    Mohd, Zulaikha Hana; Ujang, Uznir; Choon, Tan Liat

    2017-01-01

    leakage and exfoliation of wall. One of the initiatives for maintaining and documenting this heritage house is through Three-dimensional (3D) of technology. 3D city models are widely used now and much used by researchers for management and analysis. CityGML is a standard tool that usually used...... by researchers to exchange, storing and managing virtual 3D city models either geometric and semantic information. Moreover, it also represent multi-scale of 3D model in five level of details (LoDs) whereby each of level give a distinctive functions. The extension of CityGML was recently introduced and can...

  10. Improving plasma shaping accuracy through consolidation of control model maintenance, diagnostic calibration, and hardware change control

    International Nuclear Information System (INIS)

    Baggest, D.S.; Rothweil, D.A.; Pang, S.

    1995-12-01

    With the advent of more sophisticated techniques for control of tokamak plasmas comes the requirement for increasingly more accurate models of plasma processes and tokamak systems. Development of accurate models for DIII-D power systems, vessel, and poloidal coils is already complete, while work continues in development of general plasma response modeling techniques. Increased accuracy in estimates of parameters to be controlled is also required. It is important to ensure that errors in supporting systems such as diagnostic and command circuits do not limit the accuracy of plasma parameter estimates or inhibit the ability to derive accurate plasma/tokamak system models. To address this issue, we have developed more formal power systems change control and power system/magnetic diagnostics calibration procedures. This paper discusses our approach to consolidating the tasks in these closely related areas. This includes, for example, defining criteria for when diagnostics should be re-calibrated along with required calibration tolerances, and implementing methods for tracking power systems hardware modifications and the resultant changes to control models

  11. Awakening consumer stewardship of health benefits: prevalence and differentiation of new health plan models.

    Science.gov (United States)

    Rosenthal, Meredith; Milstein, Arnold

    2004-08-01

    Despite widespread publicity of consumer-directed health plans, little is known about their prevalence and the extent to which their designs adequately reflect and support consumerism. We examined three types of consumer-directed health plans: health reimbursement accounts (HRAs), premium-tiered, and point-of-care tiered benefit plans. We sought to measure the extent to which these plans had diffused, as well as to provide a critical look at the ways in which these plans support consumerism. Consumerism in this context refers to efforts to enable informed consumer choice and consumers' involvement in managing their health. We also wished to determine whether mainstream health plans-health maintenance organization (HMO), point of service (POS), and preferred provider organization (PPO) models-were being influenced by consumerism. Our study uses national survey data collected by Mercer Human Resource Consulting from 680 national and regional commercial health benefit plans on HMO, PPO, POS, and consumer-directed products. We defined consumer-directed products as health benefit plans that provided (1) consumer incentives to select more economical health care options, including self-care and no care, and (2) information and support to inform such selections. We asked health plans that offered consumer-directed products about 2003 enrollment, basic design features, and the availability of decision support. We also asked mainstream health plans about their activities that supported consumerism (e.g., proactive outreach to inform or influence enrollee behavior, such as self-management or preventive care, reminders sent to patients with identified medical conditions.) We analyzed survey responses for all four product lines in order to identify those plans that offer health reimbursement accounts (HRAs), premium-tiered, or point-of-care tiered models as well as efforts of mainstream health plans to engage informed consumer decision making. The majority of enrollees in

  12. PTEN phosphatase-independent maintenance of glandular morphology in a predictive colorectal cancer model system.

    Science.gov (United States)

    Jagan, Ishaan C; Deevi, Ravi K; Fatehullah, Aliya; Topley, Rebecca; Eves, Joshua; Stevenson, Michael; Loughrey, Maurice; Arthur, Kenneth; Campbell, Frederick Charles

    2013-11-01

    Organotypic models may provide mechanistic insight into colorectal cancer (CRC) morphology. Three-dimensional (3D) colorectal gland formation is regulated by phosphatase and tensin homologue deleted on chromosome 10 (PTEN) coupling of cell division cycle 42 (cdc42) to atypical protein kinase C (aPKC). This study investigated PTEN phosphatase-dependent and phosphatase-independent morphogenic functions in 3D models and assessed translational relevance in human studies. Isogenic PTEN-expressing or PTEN-deficient 3D colorectal cultures were used. In translational studies, apical aPKC activity readout was assessed against apical membrane (AM) orientation and gland morphology in 3D models and human CRC. We found that catalytically active or inactive PTEN constructs containing an intact C2 domain enhanced cdc42 activity, whereas mutants of the C2 domain calcium binding region 3 membrane-binding loop (M-CBR3) were ineffective. The isolated PTEN C2 domain (C2) accumulated in membrane fractions, but C2 M-CBR3 remained in cytosol. Transfection of C2 but not C2 M-CBR3 rescued defective AM orientation and 3D morphogenesis of PTEN-deficient Caco-2 cultures. The signal intensity of apical phospho-aPKC correlated with that of Na(+)/H(+) exchanger regulatory factor-1 (NHERF-1) in the 3D model. Apical NHERF-1 intensity thus provided readout of apical aPKC activity and associated with glandular morphology in the model system and human colon. Low apical NHERF-1 intensity in CRC associated with disruption of glandular architecture, high cancer grade, and metastatic dissemination. We conclude that the membrane-binding function of the catalytically inert PTEN C2 domain influences cdc42/aPKC-dependent AM dynamics and gland formation in a highly relevant 3D CRC morphogenesis model system.

  13. PTEN Phosphatase-Independent Maintenance of Glandular Morphology in a Predictive Colorectal Cancer Model System

    Directory of Open Access Journals (Sweden)

    Ishaan C. Jagan

    2013-11-01

    Full Text Available Organotypic models may provide mechanistic insight into colorectal cancer (CRC morphology. Three-dimensional (3D colorectal gland formation is regulated by phosphatase and tensin homologue deleted on chromosome 10 (PTEN coupling of cell division cycle 42 (cdc42 to atypical protein kinase C (aPKC. This study investigated PTEN phosphatase-dependent and phosphatase-independent morphogenic functions in 3D models and assessed translational relevance in human studies. Isogenic PTEN-expressing or PTEN-deficient 3D colorectal cultures were used. In translational studies, apical aPKC activity readout was assessed against apical membrane (AM orientation and gland morphology in 3D models and human CRC. We found that catalytically active or inactive PTEN constructs containing an intact C2 domain enhanced cdc42 activity, whereas mutants of the C2 domain calcium binding region 3 membrane-binding loop (M-CBR3 were ineffective. The isolated PTEN C2 domain (C2 accumulated in membrane fractions, but C2 M-CBR3 remained in cytosol. Transfection of C2 but not C2 M-CBR3 rescued defective AM orientation and 3D morphogenesis of PTEN-deficient Caco-2 cultures. The signal intensity of apical phospho-aPKC correlated with that of Na+/H+ exchanger regulatory factor-1 (NHERF-1 in the 3D model. Apical NHERF-1 intensity thus provided readout of apical aPKC activity and associated with glandular morphology in the model system and human colon. Low apical NHERF-1 intensity in CRC associated with disruption of glandular architecture, high cancer grade, and metastatic dissemination. We conclude that the membrane-binding function of the catalytically inert PTEN C2 domain influences cdc42/aPKC-dependent AM dynamics and gland formation in a highly relevant 3D CRC morphogenesis model system.

  14. Simulation modeling for the health care manager.

    Science.gov (United States)

    Kennedy, Michael H

    2009-01-01

    This article addresses the use of simulation software to solve administrative problems faced by health care managers. Spreadsheet add-ins, process simulation software, and discrete event simulation software are available at a range of costs and complexity. All use the Monte Carlo method to realistically integrate probability distributions into models of the health care environment. Problems typically addressed by health care simulation modeling are facility planning, resource allocation, staffing, patient flow and wait time, routing and transportation, supply chain management, and process improvement.

  15. Integrating health belief model and technology acceptance model: an investigation of health-related internet use.

    Science.gov (United States)

    Ahadzadeh, Ashraf Sadat; Pahlevan Sharif, Saeed; Ong, Fon Sim; Khong, Kok Wei

    2015-02-19

    Today, people use the Internet to satisfy health-related information and communication needs. In Malaysia, Internet use for health management has become increasingly significant due to the increase in the incidence of chronic diseases, in particular among urban women and their desire to stay healthy. Past studies adopted the Technology Acceptance Model (TAM) and Health Belief Model (HBM) independently to explain Internet use for health-related purposes. Although both the TAM and HBM have their own merits, independently they lack the ability to explain the cognition and the related mechanism in which individuals use the Internet for health purposes. This study aimed to examine the influence of perceived health risk and health consciousness on health-related Internet use based on the HBM. Drawing on the TAM, it also tested the mediating effects of perceived usefulness of the Internet for health information and attitude toward Internet use for health purposes for the relationship between health-related factors, namely perceived health risk and health consciousness on health-related Internet use. Data obtained for the current study were collected using purposive sampling; the sample consisted of women in Malaysia who had Internet access. The partial least squares structural equation modeling method was used to test the research hypotheses developed. Perceived health risk (β=.135, t1999=2.676) and health consciousness (β=.447, t1999=9.168) had a positive influence on health-related Internet use. Moreover, perceived usefulness of the Internet and attitude toward Internet use for health-related purposes partially mediated the influence of health consciousness on health-related Internet use (β=.025, t1999=3.234), whereas the effect of perceived health risk on health-related Internet use was fully mediated by perceived usefulness of the Internet and attitude (β=.029, t1999=3.609). These results suggest the central role of perceived usefulness of the Internet and

  16. Operation and maintenance manual Bendix model M-163-01 monitor-controller

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, L.E.

    1981-04-01

    As a part of the modular automatic welding system, the Model M-163-01 Monitor-Controlled permits weld energy and electrode force values to be preset for each of six different weld combinations. It also provides in-process monitoring of RMS current, electrode force, pulse position, and a digital printout of weld data.

  17. Function Model for Community Health Service Information

    Science.gov (United States)

    Yang, Peng; Pan, Feng; Liu, Danhong; Xu, Yongyong

    In order to construct a function model of community health service (CHS) information for development of CHS information management system, Integration Definition for Function Modeling (IDEF0), an IEEE standard which is extended from Structured Analysis and Design(SADT) and now is a widely used function modeling method, was used to classifying its information from top to bottom. The contents of every level of the model were described and coded. Then function model for CHS information, which includes 4 super-classes, 15 classes and 28 sub-classed of business function, 43 business processes and 168 business activities, was established. This model can facilitate information management system development and workflow refinement.

  18. Black tea and maintenance of normal endotheliumdependent vasodilation: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Sjödin, Anders Mikael

    2018-01-01

    on the scientific substantiation of a health claim related to black tea and maintenance of normal endotheliumdependent vasodilation. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. The food proposed by the applicant as the subject of the health...... claim is black tea beverages, either freshly prepared or reconstituted from water extract powders of black tea, characterised by the content of flavanols (expressed as catechins plus theaflavins) of at least 30 mg per 200 mL serving. The Panel considers that black tea characterised by the content....... Of the five human intervention studies provided on the chronic effect of black tea consumption on endothelium-dependent vasodilation, two investigated the effect after regular consumption of black tea for a sufficiently long time period (i.e. at least 4 weeks). These two studies did not allow an effect...

  19. A multi state simulation model of the maintenance for a power generating station

    International Nuclear Information System (INIS)

    Karlsson, B.O.

    1980-09-01

    A multistate simulation model for a thermal power generating station is described. The performance is modelled as a function of the system structure, the component reliability, the number of repair crews, the repair times and the availability of spare parts. Each component can be in either of four states: failed, working, postponed, or standby. A component will be in the postponed state, if due to failures in other components it is turned off. Two different types of failures are assumed: minor and severe. Evaluation of the system state is performed by repeated use of four elementary system functions: series, parallel, k-out-of-n, and standby k/l/n. Numerical results for a case study are presented. (author)

  20. HERITAGE HOUSE MAINTENANCE USING 3D CITY MODEL APPLICATION DOMAIN EXTENSION APPROACH

    Directory of Open Access Journals (Sweden)

    Z. H. Mohd

    2017-11-01

    Full Text Available Heritage house is part of the architectural heritage of Malaysia that highly valued. Many efforts by the Department of Heritage to preserve this heritage house such as monitoring the damage problems of heritage house. The damage problems of heritage house might be caused by wooden decay, roof leakage and exfoliation of wall. One of the initiatives for maintaining and documenting this heritage house is through Three-dimensional (3D of technology. 3D city models are widely used now and much used by researchers for management and analysis. CityGML is a standard tool that usually used by researchers to exchange, storing and managing virtual 3D city models either geometric and semantic information. Moreover, it also represent multi-scale of 3D model in five level of details (LoDs whereby each of level give a distinctive functions. The extension of CityGML was recently introduced and can be used for problems monitoring and the number of habitants of a house.

  1. Health care management modelling: a process perspective

    NARCIS (Netherlands)

    Vissers, J.M.H.

    1998-01-01

    Modelling-based health care management ought to become just as popular as evidence based medicine. Making managerial decisions based on evidence by modelling efforts is certainly a step forward. Examples can be given of many successful applications in different areas of decision making: disease

  2. Evaluation of prototype Advanced Life Support (ALS) pack for use by the Health Maintenance Facility (HMF) on Space Station Freedom (SSF)

    Science.gov (United States)

    Krupa, Debra T.; Gosbee, John; Murphy, Linda; Kizzee, Victor D.

    1991-01-01

    The purpose is to evaluate the prototype Advanced Life Support (ALS) Pack which was developed for the Health Maintenance Facility (HMF). This pack will enable the Crew Medical Officer (CMO) to have ready access to advanced life support supplies and equipment for time critical responses to any situation within the Space Station Freedom. The objectives are: (1) to evaluate the design of the pack; and (2) to collect comments for revision to the design of the pack. The in-flight test procedures and other aspects of the KC-135 parabolic test flight to simulate weightlessness are presented.

  3. Long-term effects of 1-year maintenance training on physical functioning and health status in patients with COPD: A randomized controlled study

    DEFF Research Database (Denmark)

    Ringbaek, Thomas; Brondum, Eva; Martinez, Gerd

    2010-01-01

    PURPOSE: To examine whether maintenance training (MT) for 1 year improved the long-term effects of a 7-week chronic obstructive pulmonary disease (COPD) rehabilitation program. METHODS: After a 7-week outpatient rehabilitation program, 96 patients with COPD were randomized to either an MT group (n...... study period. Primary effect parameters were Endurance Shuttle Walk Test (ESWT) time and health status (St. George's Respiratory Questionnaire, SGRQ). Secondary effect parameters were adherence to supervised training, dropout rates, and hospitalization. RESULTS: Compared with the control group, the MT...... or hospital admissions, compared with unsupervised daily training at home. The effect of the MT was closely related to adherence to the program....

  4. Modeling and simulation of maintenance treatment in first-line non-small cell lung cancer with external validation

    International Nuclear Information System (INIS)

    Han, Kelong; Claret, Laurent; Sandler, Alan; Das, Asha; Jin, Jin; Bruno, Rene

    2016-01-01

    Maintenance treatment (MTx) in responders following first-line treatment has been investigated and practiced for many cancers. Modeling and simulation may support interpretation of interim data and development decisions. We aimed to develop a modeling framework to simulate overall survival (OS) for MTx in NSCLC using tumor growth inhibition (TGI) data. TGI metrics were estimated using longitudinal tumor size data from two Phase III first-line NSCLC studies evaluating bevacizumab and erlotinib as MTx in 1632 patients. Baseline prognostic factors and TGI metric estimates were assessed in multivariate parametric models to predict OS. The OS model was externally validated by simulating a third independent NSCLC study (n = 253) based on interim TGI data (up to progression-free survival database lock). The third study evaluated pemetrexed + bevacizumab vs. bevacizumab alone as MTx. Time-to-tumor-growth (TTG) was the best TGI metric to predict OS. TTG, baseline tumor size, ECOG score, Asian ethnicity, age, and gender were significant covariates in the final OS model. The OS model was qualified by simulating OS distributions and hazard ratios (HR) in the two studies used for model-building. Simulations of the third independent study based on interim TGI data showed that pemetrexed + bevacizumab MTx was unlikely to significantly prolong OS vs. bevacizumab alone given the current sample size (predicted HR: 0.81; 95 % prediction interval: 0.59–1.09). Predicted median OS was 17.3 months and 14.7 months in both arms, respectively. These simulations are consistent with the results of the final OS analysis published 2 years later (observed HR: 0.87; 95 % confidence interval: 0.63–1.21). Final observed median OS was 17.1 months and 13.2 months in both arms, respectively, consistent with our predictions. A robust TGI-OS model was developed for MTx in NSCLC. TTG captures treatment effect. The model successfully predicted the OS outcomes of an independent study based on interim

  5. Modeling and simulation of maintenance treatment in first-line non-small cell lung cancer with external validation.

    Science.gov (United States)

    Han, Kelong; Claret, Laurent; Sandler, Alan; Das, Asha; Jin, Jin; Bruno, Rene

    2016-07-13

    Maintenance treatment (MTx) in responders following first-line treatment has been investigated and practiced for many cancers. Modeling and simulation may support interpretation of interim data and development decisions. We aimed to develop a modeling framework to simulate overall survival (OS) for MTx in NSCLC using tumor growth inhibition (TGI) data. TGI metrics were estimated using longitudinal tumor size data from two Phase III first-line NSCLC studies evaluating bevacizumab and erlotinib as MTx in 1632 patients. Baseline prognostic factors and TGI metric estimates were assessed in multivariate parametric models to predict OS. The OS model was externally validated by simulating a third independent NSCLC study (n = 253) based on interim TGI data (up to progression-free survival database lock). The third study evaluated pemetrexed + bevacizumab vs. bevacizumab alone as MTx. Time-to-tumor-growth (TTG) was the best TGI metric to predict OS. TTG, baseline tumor size, ECOG score, Asian ethnicity, age, and gender were significant covariates in the final OS model. The OS model was qualified by simulating OS distributions and hazard ratios (HR) in the two studies used for model-building. Simulations of the third independent study based on interim TGI data showed that pemetrexed + bevacizumab MTx was unlikely to significantly prolong OS vs. bevacizumab alone given the current sample size (predicted HR: 0.81; 95 % prediction interval: 0.59-1.09). Predicted median OS was 17.3 months and 14.7 months in both arms, respectively. These simulations are consistent with the results of the final OS analysis published 2 years later (observed HR: 0.87; 95 % confidence interval: 0.63-1.21). Final observed median OS was 17.1 months and 13.2 months in both arms, respectively, consistent with our predictions. A robust TGI-OS model was developed for MTx in NSCLC. TTG captures treatment effect. The model successfully predicted the OS outcomes of an independent study

  6. Intelligent model-based diagnostics for vehicle health management

    Science.gov (United States)

    Luo, Jianhui; Tu, Fang; Azam, Mohammad S.; Pattipati, Krishna R.; Willett, Peter K.; Qiao, Liu; Kawamoto, Masayuki

    2003-08-01

    The recent advances in sensor technology, remote communication and computational capabilities, and standardized hardware/software interfaces are creating a dramatic shift in the way the health of vehicles is monitored and managed. These advances facilitate remote monitoring, diagnosis and condition-based maintenance of automotive systems. With the increased sophistication of electronic control systems in vehicles, there is a concomitant increased difficulty in the identification of the malfunction phenomena. Consequently, the current rule-based diagnostic systems are difficult to develop, validate and maintain. New intelligent model-based diagnostic methodologies that exploit the advances in sensor, telecommunications, computing and software technologies are needed. In this paper, we will investigate hybrid model-based techniques that seamlessly employ quantitative (analytical) models and graph-based dependency models for intelligent diagnosis. Automotive engineers have found quantitative simulation (e.g. MATLAB/SIMULINK) to be a vital tool in the development of advanced control systems. The hybrid method exploits this capability to improve the diagnostic system's accuracy and consistency, utilizes existing validated knowledge on rule-based methods, enables remote diagnosis, and responds to the challenges of increased system complexity. The solution is generic and has the potential for application in a wide range of systems.

  7. Development of hardware system using temperature and vibration maintenance models integration concepts for conventional machines monitoring: a case study

    Science.gov (United States)

    Adeyeri, Michael Kanisuru; Mpofu, Khumbulani; Kareem, Buliaminu

    2016-03-01

    This article describes the integration of temperature and vibration models for maintenance monitoring of conventional machinery parts in which their optimal and best functionalities are affected by abnormal changes in temperature and vibration values thereby resulting in machine failures, machines breakdown, poor quality of products, inability to meeting customers' demand, poor inventory control and just to mention a few. The work entails the use of temperature and vibration sensors as monitoring probes programmed in microcontroller using C language. The developed hardware consists of vibration sensor of ADXL345, temperature sensor of AD594/595 of type K thermocouple, microcontroller, graphic liquid crystal display, real time clock, etc. The hardware is divided into two: one is based at the workstation (majorly meant to monitor machines behaviour) and the other at the base station (meant to receive transmission of machines information sent from the workstation), working cooperatively for effective functionalities. The resulting hardware built was calibrated, tested using model verification and validated through principles pivoted on least square and regression analysis approach using data read from the gear boxes of extruding and cutting machines used for polyethylene bag production. The results got therein confirmed related correlation existing between time, vibration and temperature, which are reflections of effective formulation of the developed concept.

  8. Effects of Methadone Maintenance Treatment on Decision-Making Processes in Heroin-Abusers: A Cognitive Modeling Analysis

    Directory of Open Access Journals (Sweden)

    Arash Khodadadi

    2010-05-01

    Full Text Available A B S T R A C TIntroduction: Although decision-making processes have become a principal target of study among addiction researchers, few researches are published according to effects of different treatment methods on the cognitive processes underlying decision making up to now. Utilizing cognitive modeling method, in this paper we examine the effects of Methadone maintenance treatment (MMT on cognitive processes underlying decision-making disorders in heroin-abusers. Methods: For this purpose, for the first time, we use the balloon analog risk task (BART to assess the decision-making ability of heroin-abusers before and after treatment and compare it to the non heroin-dependent subjects. Results: Results demonstrate that heroin-abusers show more risky behavior than other groups. But, there is no difference between the performance of heroin-abusers after 6 months of MMT and control group. Modeling subjects’ behavior in BART reveals that poor performance in heroin-abusers is due to reward-dependency and insensitivity to evaluation. Discussion: Results show that 6 months of MMT decreases reward-dependency and increases sensitivity to evaluation.

  9. Opportune maintenance and predictive maintenance decision support

    OpenAIRE

    Thomas , Edouard; Levrat , Eric; Iung , Benoît; Cocheteux , Pierre

    2009-01-01

    International audience; Conventional maintenance strategies on a single component are being phased out in favour of more predictive maintenance actions. These new kinds of actions are performed in order to control the global performances of the whole industrial system. They are anticipative in nature, which allows a maintenance expert to consider non-already-planned maintenance actions. Two questions naturally emerge: when to perform a predictive maintenance action; how a maintenance expert c...

  10. The salutogenic model of health in health promotion research.

    Science.gov (United States)

    Mittelmark, Maurice B; Bull, Torill

    2013-06-01

    Despite health promotion's enthusiasm for the salutogenic model of health, researchers have paid little attention to Antonovsky's central ideas about the ease/dis-ease continuum, defined in terms of 'breakdown' (the severity of pain and functional limitations, and the degree medical care is called for, irrespective of specific diseases). Rather, salutogenesis research has a strong focus on how sense of coherence relates to a wide range of specific diseases and illness endpoints. We address two questions: Why has Antonovsky's health concept failed to stimulate research on breakdown, and how can the present emphasis on disease be complemented by an emphasis on positive well-being in the salutogenic model? We show that (i) the breakdown concept of health as specified by Antonovsky is circular in definition, (ii) it is not measured on the 'required' ease/dis-ease continuum, (iii) it is not measureable by any validated or reliability-tested assessment tool, and (iv) it has not so much been rejected by health promotion, as it has not been considered at all. We show that Antonovsky came to view breakdown as but one aspect of well-being. He was open to the idea of well-being as something more positive than the absence of pain, suffering and need for medical care. We suggest ways to move salutogenesis research in the direction of well-being in its positive sense.

  11. Changing beliefs about leisure noise: using health promotion models to investigate young people's engagement with, and attitudes towards, hearing health.

    Science.gov (United States)

    Gilliver, Megan; Beach, Elizabeth Francis; Williams, Warwick

    2015-04-01

    To investigate factors influencing young people's motivation to reduce their leisure noise exposure, and protect their hearing health. Questionnaires were conducted online to investigate young people's hearing health attitudes and behaviour. Items were developed using an integrated health promotion approach. The stage of change model was used to group participants in relation to their engagement with noise reduction behaviour. The health belief model was used to compare each group's perceptions of susceptibility and severity of hearing loss, as well as the benefits and barriers to noise reduction. Results are presented for 1196 young Australians aged between 18 and 35 years. Participants' engagement with noise reduction behaviour was used to assign them to stage of change groupings: Maintenance (11%), Action (28%), Contemplation (14%), or Pre-contemplation (43%). Each group's responses to health belief model items highlighted key differences across the different stages of engagement. Future hearing health promotion may benefit from tailoring intervention activities to best suit the stage of change of individuals. Different information may be useful at each stage to best support and motivate young people to look after their hearing health.

  12. [Health for refugees - the Bremen model].

    Science.gov (United States)

    Mohammadzadeh, Zahra; Jung, Felicitas; Lelgemann, Monika

    2016-05-01

    The Bremen model recognizes that refugee health care has to go beyond merely checking for the prevalence of contagious diseases. Elementary health care offered in the reception centre and transitory facilities is based on voluntary acceptance by the refugees. At the same time, legal requirements for the medical reception of refugees are observed. In addition, doctors performing the initial medical examination are enabled to cover acute care on the spot. During the preliminary phase of immigration refugees are allowed to see a doctor in their facility repeatedly. After a certain time, they are provided with a health card permitting limited access to regular care outside of their facility. The current rise of refugee numbers affects the situation of Bremen health care for adult as well as juvenile refugees. In spite of the increase, health care standards are maintained by means of the health card. From 2011 to 2014, "Factors influencing health status and contact with health services" averaged 29.6 % in the health check data. Diseases of the respiratory system (18.1 %) and "symptoms, signs and abnormal findings not elsewhere classified" (16.9 %) ranked second and third, respectively. Diseases of the digestive system (6.1 %) of the musculoskeletal system (6 %) and of the skin and subcutaneous tissue (3.6 %) followed. Infectious diseases such as HIV infections, hepatitis or tuberculosis were seldom.

  13. Network maintenance

    CERN Multimedia

    GS Department

    2009-01-01

    A site-wide network maintenance operation has been scheduled for Saturday 28 February. Most of the network devices of the general purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites throughout the day. This upgrade will not affect the Computer Centre itself, Building 613, the Technical Network and the LHC experiments, dedicated networks at the pits. For further details of this intervention, please contact Netops by phone 74927 or e-mail mailto:Netops@cern.ch. IT/CS Group

  14. Network maintenance

    CERN Multimedia

    IT Department

    2009-01-01

    A site wide network maintenance has been scheduled for Saturday 28 February. Most of the network devices of the General Purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites along this day. This upgrade will not affect: the Computer centre itself, building 613, the Technical Network and the LHC experiments dedicated networks at the pits. Should you need more details on this intervention, please contact Netops by phone 74927 or email mailto:Netops@cern.ch. IT/CS Group

  15. Integrating Models of Diffusion and Behavior to Predict Innovation Adoption, Maintenance, and Social Diffusion.

    Science.gov (United States)

    Smith, Rachel A; Kim, Youllee; Zhu, Xun; Doudou, Dimi Théodore; Sternberg, Eleanore D; Thomas, Matthew B

    2018-01-01

    This study documents an investigation into the adoption and diffusion of eave tubes, a novel mosquito vector control, during a large-scale scientific field trial in West Africa. The diffusion of innovations (DOI) and the integrated model of behavior (IMB) were integrated (i.e., innovation attributes with attitudes and social pressures with norms) to predict participants' (N = 329) diffusion intentions. The findings showed that positive attitudes about the innovation's attributes were a consistent positive predictor of diffusion intentions: adopting it, maintaining it, and talking with others about it. As expected by the DOI and the IMB, the social pressure created by a descriptive norm positively predicted intentions to adopt and maintain the innovation. Drawing upon sharing research, we argued that the descriptive norm may dampen future talk about the innovation, because it may no longer be seen as a novel, useful topic to discuss. As predicted, the results showed that as the descriptive norm increased, the intention to talk about the innovation decreased. These results provide broad support for integrating the DOI and the IMB to predict diffusion and for efforts to draw on other research to understand motivations for social diffusion.

  16. Maintenance performance improvement with System Dynamics : A Corrective Maintenance showcase

    NARCIS (Netherlands)

    Deenen, R.E.M.; Van Daalen, C.E.; Koene, E.G.C.

    2008-01-01

    This paper presents a case study of an analysis of a Corrective Maintenance process to realize performance improvement. The Corrective Maintenance process is supported by SAP, which has indicated the performance realisation problem. System Dynamics is used in a Group Model Building process to

  17. Toward a humanistic model in health communication.

    Science.gov (United States)

    Werder, Olaf

    2017-03-01

    Since the key to effective health communication lies in its ability to communicate well, some of its core problems are those that relate to the sharing of meaning between communicators. In elaborating on these problems, this paper offers two key propositions: one, health communication has to pass through the filter of a particular world view that creates a discrepancy between expected and actual message reception and response. Two, the assumption of a rational human actor made implicitly by most health psychological models is a contestable issue, as many times message recipients do not follow a cognitive judgment process. The phenomenon of resisting health messages by reasonable people asks the question whether we ought to rethink our adherence to a particular vision of human health as many times the adverse reaction to behaviour modification occurs as the result of a particular dialogical or discursive situation. At the same time, most motivational decisions in people's daily routines are automatic and use a concept known as self-identity to give stability to their behaviour patterns. Finally, health communication as part of organised government practices adheres to predominant value perspectives within health promotion practice that affect the manner in which health issues become problematised. This paper proposes a humanistic model that aims to pay attention to the intricacies of human communication by addressing all of the above problems in turn. It interprets the sharing of meaning element in human communication and addresses the question of how the idea of health is created through discourse. As such, it offers a complementary and constructive paradigm and set of approaches to understand health, its meanings and communication.

  18. Understanding Business Models in Health Care.

    Science.gov (United States)

    Sharan, Alok D; Schroeder, Gregory D; West, Michael E; Vaccaro, Alexander R

    2016-05-01

    The increasing focus on the costs of care is forcing health care organizations to critically look at their basic set of processes and activities, to determine what type of value they can deliver. A business model describes the resources, processes, and cost assumptions that an organization makes that will lead to the delivery of a unique value proposition to a customer. As health care organizations are beginning to transform their structure in preparation for a value-based delivery system, understanding business model theory can help in the redesign process.

  19. Modelo de gerenciamento da manutenção de equipamentos de radiologia convencional Maintenance management model for conventional radiology equipments

    Directory of Open Access Journals (Sweden)

    Nelson Fraga do Couto

    2003-12-01

    Full Text Available Foi elaborado um modelo de gerenciamento da manutenção dos equipamentos convencionais de raios X no Hospital Universitário Clementino Fraga Filho. O modelo foi implementado em várias etapas, que incluíram visitas a centros hospitalares que gerenciam seus equipamentos, linha de colaboração com a Fundação Oswaldo Cruz para realização de cursos e treinamento de técnicos de eletrônica do hospital, montagem de uma esquemateca dos equipamentos em uso, criação de um programa de gerenciamento utilizando um banco de dados na plataforma Microsoft Windows 98-Access, levantamento operacional e condições de funcionamento dos equipamentos. A criação de uma nova rotina nas manutenções vai ao encontro das necessidades de reduzir o tempo de atendimento, custos, e de melhoria na qualidade da imagem em um serviço de radiodiagnóstico, atendendo também às exigências da Portaria 453/98 do Ministério da Saúde.We developed a management model for maintenance of hospital radiological X-ray equipment. The model was implemented in several steps including visits to other hospitals where equipment management is also done, collaboration work with "Fundação Oswaldo Cruz" for the realization of courses and a training program for the hospital electronic technicians, organization of a small library with the schemes of the radiological equipment in use at "Hospital Universitário Clementino Fraga Filho", Rio de Janeiro, Brazil, development of a management software using a database from Access (Microsoft Windows and evaluation of the performance of the radiological equipment. The implementation of a new routine for equipment maintenance fulfils the need for reducing repair delay and costs, improving image quality in radiodiagnosis services, and complying with resolution 453/98 of the Brazilian Ministry of Health.

  20. Selecting Suitable Candidates for Predictive Maintenance

    NARCIS (Netherlands)

    Tiddens, Wieger Willem; Braaksma, Anne Johannes Jan; Tinga, Tiedo

    2018-01-01

    Predictive maintenance (PdM) or Prognostics and Health Management (PHM) assists in better predicting the future state of physical assets and making timely and better-informed maintenance decisions. Many companies nowadays ambition the implementation of such an advanced maintenance policy. However,

  1. ATP Maintenance via Two Types of ATP Regulators Mitigates Pathological Phenotypes in Mouse Models of Parkinson's Disease.

    Science.gov (United States)

    Nakano, Masaki; Imamura, Hiromi; Sasaoka, Norio; Yamamoto, Masamichi; Uemura, Norihito; Shudo, Toshiyuki; Fuchigami, Tomohiro; Takahashi, Ryosuke; Kakizuka, Akira

    2017-08-01

    Parkinson's disease is assumed to be caused by mitochondrial dysfunction in the affected dopaminergic neurons in the brain. We have recently created small chemicals, KUSs (Kyoto University Substances), which can reduce cellular ATP consumption. By contrast, agonistic ligands of ERRs (estrogen receptor-related receptors) are expected to raise cellular ATP levels via enhancing ATP production. Here, we show that esculetin functions as an ERR agonist, and its addition to culture media enhances glycolysis and mitochondrial respiration, leading to elevated cellular ATP levels. Subsequently, we show the neuroprotective efficacies of KUSs, esculetin, and GSK4716 (an ERRγ agonist) against cell death in Parkinson's disease models. In the surviving neurons, ATP levels and expression levels of α-synuclein and CHOP (an ER stress-mediated cell death executor) were all rectified. We propose that maintenance of ATP levels, by inhibiting ATP consumption or enhancing ATP production, or both, would be a promising therapeutic strategy for Parkinson's disease. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  2. CXCL10 is critical for the progression and maintenance of depigmentation in a mouse model of vitiligo

    Science.gov (United States)

    Rashighi, Mehdi; Agarwal, Priti; Richmond, Jillian M; Harris, Tajie H; Dresser, Karen; Su, Mingwan; Zhou, Youwen; Deng, April; Hunter, Chris A; Luster, Andrew D; Harris, John E

    2014-01-01

    Vitiligo is an autoimmune disease of the skin that results in disfiguring white spots. There are no FDA-approved treatments for vitiligo, and most off-label treatments yield unsatisfactory results. Vitiligo patients have increased numbers of autoreactive, melanocyte-specific CD8+ T cells in the skin and blood, which are directly responsible for melanocyte destruction. Here we report that gene expression in lesional skin from vitiligo patients reveals an IFN-γ-specific signature, including the chemokine CXCL10. CXCL10 is elevated in both vitiligo patient skin and serum and CXCR3, its receptor, is expressed on pathogenic T cells. To address the function of CXCL10 in vitiligo, we employed a mouse model of disease that also exhibits an IFN-γ-specific gene signature, expression of CXCL10 in the skin, and upregulation of CXCR3 on antigen-specific T cells. Mice that receive Cxcr3−/− T cells develop minimal depigmentation, as do mice lacking Cxcl10 or treated with CXCL10 neutralizing antibody. CXCL9 promotes autoreactive T cell global recruitment to the skin but not effector function while, in contrast, CXCL10 is required for effector function and localization within the skin. Surprisingly, CXCL10 neutralization in mice with established, widespread depigmentation induces reversal of disease, evidenced by repigmentation. These data identify a critical role for CXCL10 in both the progression and maintenance of vitiligo, and thereby support inhibiting CXCL10 as a targeted treatment strategy. PMID:24523323

  3. Health informatics model for helminthiasis in Thailand.

    Science.gov (United States)

    Nithikathkul, C; Trevanich, A; Wongsaroj, T; Wongsawad, C; Reungsang, P

    2017-09-01

    At the beginning of the new millennium, helminth infections continue to be prevalent, particularly among impoverished populations. This study attempts to create the first health informatics model of helminthiasis in Thailand. The authors investigate how a health informatics model could be used to predict the control and eradication in a national control campaign. Fish-borne helminthiasis caused by Opisthorchis viverrini remains a major public health problem in many parts of South-East Asia, including Thailand, Lao PDR, Vietnam and Cambodia. The epicentre of this disease is located in north-east Thailand, where high prevalence coexists with a high incidence of cholangiocarcinoma (CHCA). The current report was conducted to determine a mathematical model of surveillance for helminthiasis while also using a geographic information system. The fish-borne helminthiasis model or the predicted equation was Y1 = 3.028 + 0.020 (elevation) - 2.098 (clay). For soil-transmitted helminthiasis, the mathematical model or the predicted equation was Y2 = -1.559 + 0.005 (rainfall) + 0.004 (elevation) - 2.198 (clay). The Ministry of Public Health has concluded that mass treatment for helminthiasis in the Thai population, targeting high-risk individuals, may be a cost-effective way to allocate limited funds. This type of approach, as well as further study on the correlation of clinical symptoms with environmental and geographic information, may offer a novel strategy to the helminth crisis.

  4. Mental health treatment teams and leadership: a systems model.

    Science.gov (United States)

    Yank, G R; Barber, J W; Spradlin, W W

    1994-10-01

    Mental health treatment teams are living systems at the group level and comprise key productive subsystems of organizations providing mental health care. Effective treatment teams, like effective organizations, are anticipatory systems that contain subsystems that model and predict future system and environmental conditions and enable responses that increase system viability. A systems analysis of treatment teams highlights their potential instability due to their tendencies to regress toward dysfunctional partial systems and their active maintenance in nonequilibrium steady states with their organizational and external environments. Team subsystems are analyzed from the viewpoints of system processes and also with regard to individuals and their roles. Boundary processes are central to effective team functioning, assure constancy of team membership, and regulate the team's interfaces with its parent agency and with the external environment. Various causes and forms of disturbed information processing within hierarchical organizations are examined, and their effects at the treatment team level are discussed. The conclusion of the discussion focuses on team leadership and how leadership expands upon the concept of the decider subsystem to include role and personal factors to the team's leaders, and functions that are anticipatory and integrative in nature. Effective leaders must set appropriate thresholds for feedback regulation processes, and balance several pairs of seemingly opposing forces, including homeostasis and development, role differentiation and role overlap, and personal accountability and empowerment of others.

  5. Tele-facilities for medicine, imaging, quality controls and maintenance services in the health sector for the developing countries and its present and future scope in Bangladesh

    International Nuclear Information System (INIS)

    Jahangir, Saleh Mahmud; Xie, Y.; Uddin, Rokon Md.; Haque, Mohammod Abu Sayid; Hoq, Mahbubul; Mawla, Yasmeen; Morium, Tasnim

    2002-01-01

    The information revolution is transforming health technology itself. With the development of international fiberoptic networks, satellite communications and the ever expanding Internet, technology is now going from revolutionary to routine, from unimaginable to indispensable. There has been little practical experience with telemedicine of a direct clinical kind in the developing world which contains 80% of the world's population. In the 45 poorest countries, it is estimated that only 50% of the population have access to health services. Arguably, it is those same countries that stand to gain most from a simple and cheap telemedicine system, on the principle that it could improve access to health care specialists and enhance research and the education of local health care workers. The work of the Swinfen Charitable trust demonstrates, useful clinical and educational results can be achieved using low cost telemedicine methods. As with the rest of telemedicine, the guiding principle seems to be that it is important to be clear about what problem we are trying to solve. Bangladesh has already entered the age of telemedicine. Under the umbrella of the IAEA TC Project on tele-nuclear medicine and tele-maintenance of nuclear medical equipment it will gradually step forward to reach its desired goal. What role telemedicine will play in the developing countries is yet to be determined. In terms of global health care the relevancy of telemedicine can only be ascertained after successful implementation of these projects

  6. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to formulated palm and oat oil emulsion and contribution to the maintenance or achievement of a normal body weight (ID 577) and maintenance of body weight after weight

    DEFF Research Database (Denmark)

    Tetens, Inge

    claims in relation to formulated palm and oat oil emulsion and contribution to the maintenance or achievement of a normal body weight and maintenance of body weight after weight loss. The scientific substantiation is based on the information provided by the Member States in the consolidated list...... of Article 13 health claims and references that EFSA has received from Member States or directly from stakeholders. The food constituent that is the subject of the health claims is formulated palm and oat oil emulsion. The Panel considers that formulated palm and oat oil emulsion is sufficiently...

  7. 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

  8. Establishment, maintenance and in vitro and in vivo applications of primary human glioblastoma multiforme (GBM) xenograft models for translational biology studies and drug discovery.

    Science.gov (United States)

    Carlson, Brett L; Pokorny, Jenny L; Schroeder, Mark A; Sarkaria, Jann N

    2011-03-01

    Development of clinically relevant tumor model systems for glioblastoma multiforme (GBM) is important for advancement of basic and translational biology. One model that has gained wide acceptance in the neuro-oncology community is the primary xenograft model. This model entails the engraftment of patient tumor specimens into the flank of nude mice and subsequent serial passage of these tumors in the flank of mice. These tumors are then used to establish short-term explant cultures or intracranial xenografts. This unit describes detailed procedures for establishment, maintenance, and utilization of a primary GBM xenograft panel for the purpose of using them as tumor models for basic or translational studies.

  9. Prediction of warfarin maintenance dose in Han Chinese patients using a mechanistic model based on genetic and non-genetic factors.

    Science.gov (United States)

    Lu, Yuan; Yang, Jinbo; Zhang, Haiyan; Yang, Jin

    2013-07-01

    Many attempts have been made to predict the warfarin maintenance dose in patients beginning warfarin therapy using a descriptive model based on multiple linear regression. Here we report the first attempt to develop a comprehensive mechanistic model integrating in vitro-in vivo extrapolation (IVIVE) with a pharmacokinetic-pharmacodynamic model to predict the warfarin maintenance dose in Han Chinese patients. The model incorporates demographic factors [sex, age, body weight (BW)] and the genetic polymorphisms of cytochrome P450 (CYP) 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1). Information on the various factors, mean warfarin daily dose and International Normalized Ratio (INR) was available for a cohort of 197 Han Chinese patients. Based on in vitro enzyme kinetic parameters for S-warfarin metabolism, demographic data for Han Chinese and some scaling factors, the S-warfarin clearance (CL) was predicted for patients in the cohort with different CYP2C9 genotypes using IVIVE. The plasma concentration of S-warfarin after a single oral dose was simulated using a one-compartment pharmacokinetic model with first-order absorption and a lag time and was combined with a mechanistic coagulation model to simulate the INR response. The warfarin maintenance dose was then predicted based on the demographic data and genotypes of CYP2C9 and VKORC1 for each patient and using the observed steady-state INR (INRss) as a target value. Finally, sensitivity analysis was carried out to determine which factor(s) affect the warfarin maintenance dose most strongly. The predictive performance of this mechanistic model is not inferior to that of our previous descriptive model. There were significant differences in the mean warfarin daily dose in patients with different CYP2C9 and VKORC1 genotypes. Using IVIVE, the predicted mean CL of S-warfarin for patients with CYP2C9*1/*3 (0.092 l/h, n = 11) was 57 % less than for those with wild-type *1/*1 (0.215 l/h, n

  10. Interest in use of mHealth technology in HIV prevention and associated factors among high-risk drug users enrolled in methadone maintenance program.

    Science.gov (United States)

    Shrestha, Roman; Karki, Pramila; Copenhaver, Michael

    2017-09-01

    The adoption of mobile technologies for health (mHealth) in healthcare has grown considerably in recent years, but systematic assessment of interest in the use of mHealth in HIV prevention efforts among people who use drugs (PWUD) is lacking. We therefore examined interest in use of mHealth technology in HIV prevention and associated individual-level factors among high-risk PWUD enrolled in methadone maintenance program. A total of 400 HIV-negative PWUD, who reported drug- and/or sex-related risk behaviors completed a standardized assessment using audio computer assisted self-interview (ACASI). Results revealed significant interest in using mHealth-based approaches for specific purposes, including: to receive medication reminders (72.3%), to receive information about HIV risk reduction (65.8%), and to assess HIV risk behaviors (76.5%). Multivariate analysis showed that interest in receiving medication reminders was associated with currently taking medication and being neurocognitively impaired, whereas interest in receiving HIV-risk reduction information was associated with being non-white, married, and perceiving the person was at high-risk for contracting HIV. Similarly, participants' interested in using mHealth for HIV risk behavior assessment was associated with having recently visited a healthcare provider and exhibiting depressive symptoms. Overall, this study demonstrated that high-risk PWUD are interested in using mHealth-based tools as a key part of an HIV prevention approach within a common type of drug treatment settings. Thus, formative research on preferences for design and functionality of mHealth-based HIV prevention tools are now needed, followed by practical development, implementation, and evaluation of these new intervention strategies.

  11. Empirical validation of a model of reminiscence and health in later life.

    Science.gov (United States)

    Cappeliez, Philippe; O'Rourke, Norm

    2006-07-01

    This study addresses the adaptive value of functions of reminiscence with respect to physical and mental health in later life. A model examining the relationships between the functions of reminiscence and life satisfaction, psychiatric distress, and health is presented and tested. Self-positive (reminiscence for Identity, Death Preparation, and Problem Solving) and self-negative (reminiscence for Boredom Reduction, Bitterness Revival, and Intimacy Maintenance) functions have statistically significant and direct associations with the well-being of this sample of older adults, the first positively and the second negatively. Prosocial functions (reminiscence for Conversation, and to Teach-Inform Others) appear to have no direct link with health. Self-functions appear to have an important and lasting influence on physical and mental health, whereas prosocial functions may affect health by means of their role in emotional regulation.

  12. Hybrid Modeling Improves Health and Performance Monitoring

    Science.gov (United States)

    2007-01-01

    Scientific Monitoring Inc. was awarded a Phase I Small Business Innovation Research (SBIR) project by NASA's Dryden Flight Research Center to create a new, simplified health-monitoring approach for flight vehicles and flight equipment. The project developed a hybrid physical model concept that provided a structured approach to simplifying complex design models for use in health monitoring, allowing the output or performance of the equipment to be compared to what the design models predicted, so that deterioration or impending failure could be detected before there would be an impact on the equipment's operational capability. Based on the original modeling technology, Scientific Monitoring released I-Trend, a commercial health- and performance-monitoring software product named for its intelligent trending, diagnostics, and prognostics capabilities, as part of the company's complete ICEMS (Intelligent Condition-based Equipment Management System) suite of monitoring and advanced alerting software. I-Trend uses the hybrid physical model to better characterize the nature of health or performance alarms that result in "no fault found" false alarms. Additionally, the use of physical principles helps I-Trend identify problems sooner. I-Trend technology is currently in use in several commercial aviation programs, and the U.S. Air Force recently tapped Scientific Monitoring to develop next-generation engine health-management software for monitoring its fleet of jet engines. Scientific Monitoring has continued the original NASA work, this time under a Phase III SBIR contract with a joint NASA-Pratt & Whitney aviation security program on propulsion-controlled aircraft under missile-damaged aircraft conditions.

  13. Assessment and development of implementation models of health ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Assessment and development of implementation models of health-related ... The Contribution of Civil Society Organizations in Achieving Health for All ... Health Information for Maternal and Child Health Planning in Urban Bangladesh.

  14. Knowledge maintenance in myCBR

    OpenAIRE

    Aul, Vani; Sauer, Christian; Roth-Berghofer, Thomas

    2014-01-01

    CBR systems, being knowledge based systems, process knowledge. Due to changes in the environment a CBR system’s knowledge model can become outdated, thus creating a need for constant maintenance of said knowledge model. In this paper, we describe an implementation of (semi-)automatic knowledge maintenance of two of the four knowledge containers of CBR systems, specifically case base maintenance and maintenance of similarity measures within the CBR system development SDK myCBR. We describe our...

  15. Applying the Health Belief Model to college students' health behavior

    Science.gov (United States)

    Kim, Hak-Seon; Ahn, Joo

    2012-01-01

    The purpose of this research was to investigate how university students' nutrition beliefs influence their health behavioral intention. This study used an online survey engine (Qulatrics.com) to collect data from college students. Out of 253 questionnaires collected, 251 questionnaires (99.2%) were used for the statistical analysis. Confirmatory Factor Analysis (CFA) revealed that six dimensions, "Nutrition Confidence," "Susceptibility," "Severity," "Barrier," "Benefit," "Behavioral Intention to Eat Healthy Food," and "Behavioral Intention to do Physical Activity," had construct validity; Cronbach's alpha coefficient and composite reliabilities were tested for item reliability. The results validate that objective nutrition knowledge was a good predictor of college students' nutrition confidence. The results also clearly showed that two direct measures were significant predictors of behavioral intentions as hypothesized. Perceived benefit of eating healthy food and perceived barrier for eat healthy food to had significant effects on Behavioral Intentions and was a valid measurement to use to determine Behavioral Intentions. These findings can enhance the extant literature on the universal applicability of the model and serve as useful references for further investigations of the validity of the model within other health care or foodservice settings and for other health behavioral categories. PMID:23346306

  16. A physics-based model for maintenance of the pH gradient in the gastric mucus layer.

    Science.gov (United States)

    Lewis, Owen L; Keener, James P; Fogelson, Aaron L

    2017-12-01

    It is generally accepted that the gastric mucus layer provides a protective barrier between the lumen and the mucosa, shielding the mucosa from acid and digestive enzymes and preventing autodigestion of the stomach epithelium. However, the precise mechanisms that contribute to this protective function are still up for debate. In particular, it is not clear what physical processes are responsible for transporting hydrogen protons, secreted within the gastric pits, across the mucus layer to the lumen without acidifying the environment adjacent to the epithelium. One hypothesis is that hydrogen may be bound to the mucin polymers themselves as they are convected away from the mucosal surface and eventually degraded in the stomach lumen. It is also not clear what mechanisms prevent hydrogen from diffusing back toward the mucosal surface, thereby lowering the local pH. In this work we investigate a physics-based model of ion transport within the mucosal layer based on a Nernst-Planck-like equation. Analysis of this model shows that the mechanism of transporting protons bound to the mucus gel is capable of reproducing the trans-mucus pH gradients reported in the literature. Furthermore, when coupled with ion exchange at the epithelial surface, our analysis shows that bicarbonate secretion alone is capable of neutralizing the epithelial pH, even in the face of enormous diffusive gradients of hydrogen. Maintenance of the pH gradient is found to be robust to a wide array of perturbations in both physiological and phenomenological model parameters, suggesting a robust physiological control mechanism. NEW & NOTEWORTHY This work combines modeling techniques based on physical principles, as well as novel numerical simulations to test the plausibility of one hypothesized mechanism for proton transport across the gastric mucus layer. Results show that this mechanism is able to maintain the extreme pH gradient seen in in vivo experiments and suggests a highly robust regulation

  17. OOMM--Object-Oriented Matrix Modelling: an instrument for the integration of the Brasilia Regional Health Information System.

    Science.gov (United States)

    Cammarota, M; Huppes, V; Gaia, S; Degoulet, P

    1998-01-01

    The development of Health Information Systems is widely determined by the establishment of the underlying information models. An Object-Oriented Matrix Model (OOMM) is described which target is to facilitate the integration of the overall health system. The model is based on information modules named micro-databases that are structured in a three-dimensional network: planning, health structures and information systems. The modelling tool has been developed as a layer on top of a relational database system. A visual browser facilitates the development and maintenance of the information model. The modelling approach has been applied to the Brasilia University Hospital since 1991. The extension of the modelling approach to the Brasilia regional health system is considered.

  18. Efficiency of metabolizable energy utilization for maintenance and gain and evaluation of Small Ruminant Nutrition System model in Santa Ines sheep

    Directory of Open Access Journals (Sweden)

    José Gilson Louzada Regadas Filho

    2011-11-01

    Full Text Available This study was carried out to estimate efficiencies of the utilization of metabolizable energy for maintenance (k m and weight gain (k g and to evaluate the Small Ruminant Nutrition System (SRNS model in predicting dry matter intake and average daily gain of growing Santa Ines sheep. Twenty-four non-castrated Santa Ines sheep, at 50 days of age and with average body weight of 13.00 ± 0.56 kg, respectively, were used. After a 10-day adaptation period, four animals were slaughtered to be used as reference for estimating initial empty body weight and body composition of the other animals. The remaining animals were distributed in a random block design, with the treatments consisting of diets containing different levels of metabolizable energy (2.08, 2.28, 2.47 and 2.69 Mcal/kg of DM, with five replicates. The metabolizable energy use efficiencies for maintenance and for weight gain were calculated from the relationship between the dietary net energy for maintenance and gain and ME concentration in the diets. Evaluation of the SRNS model was performed by adjustment of simple linear regression model between the predicted (independent variable and observed (dependent variable values. The estimated energy use efficiency for maintenance (k m was 0.70; and for gain weight (kg it showed to be inversely proportional to the increase of metabolizable energy concentration in the diet. The dry matter intake predicted by the SRNS model did not statistically differ from that observed, but the model overestimated the average daily gain by 5.18%. Those results can contribute to the construction of a database, which could be condensed into several others in a predictive model of performance and feed planning for sheep reared in Brazil.

  19. Perceived benefits and barriers to exercise among persons with physical disabilities or chronic health conditions within action or maintenance stages of exercise.

    Science.gov (United States)

    Malone, Laurie A; Barfield, J P; Brasher, Joel D

    2012-10-01

    Information regarding factors that affect the initial step to exercise behavior change among persons with physical disabilities or chronic health conditions is available in the literature but much less is known regarding perceived benefits and barriers to exercise among those who are regularly active. The purpose of this study was to examine the perceived benefits and barriers to exercise among persons with physical disabilities or chronic health conditions within action or maintenance stages of exercise. Participants (n = 152) completed the Exercise Benefits and Barriers Scale (EBBS). For data analyses, disabilities and health conditions were grouped as neuromuscular, orthopedic, cardiovascular/pulmonary, or multiple conditions. Multivariate analysis of variance (MANOVA) was conducted to determine if mean differences on EBBS benefits and barriers scores existed among disability types, between sexes, among age groups, and between physical activity levels. Sum scores were computed to determine the strongest benefit and barrier responses. No significant mean differences in EBBS scores were found between disability types, sexes, age groups, or physical activity levels (p > 0.05). Strongest benefit responses varied by group. Strongest barrier responses were the same for all demographic groups: "Exercise tires me," "Exercise is hard work for me," and "I am fatigued by exercise." EBBS scores were similar across disability/health condition, sex, age, and physical activity level. Primary benefits reported were in the areas of improved physical performance and psychological outlook whereas the primary barriers were in the area of physical exertion. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Maintenance of health care providers clinical proficiency: Transdisciplinary analysis, modeling and intervention

    Science.gov (United States)

    2015-10-13

    Auscultation/Cardio 4.2.3 Auscultation/GI 4.2.4 Shape of face 4.2.5 Skin color (Neck, axillar) 4.2.6 Hip Exam 4.2.7 Weight 4.2.8 Stature 5.0 Treatment... vegetables , spend no more than 2 hours on screen time, include 1 hour of physical activity or active play, and consume little or no sugar-sweetened...learning environments, logistics analysis, and enterprise operational analytics. Ms. Ingraham also works on the application of artificial intelligence

  1. A test of the Social Identity Model of Cessation Maintenance: The content and role of social control.

    Science.gov (United States)

    Frings, Daniel; Collins, Michael; Long, Gavin; Pinto, Isabel R; Albery, Ian P

    2016-06-01

    Engagement with self-help groups is a predictor of positive outcomes for those attempting to control their addictive behaviours. In common with other groups, self-help groups have to manage non-normative ('deviant') behaviour to ensure the social values of the group remain preserved, and the group can fulfil its aims. These processes may protect group members from relapse. Drawing on the Social Identity Model of Cessation Maintenance, the current study asked a number ( n  = 44) of attendees of fellowship (AA/NA/CA) and of SMART groups to list behaviours they saw as normative and deviant, and rate a variety of responses to deviant behaviours. Costs of relapse to both the self and the group were also measured alongside self-efficacy regarding cessation and identity as both an active addict and as a member of a self-help group. Results suggest that social control responses to deviance grouped into education, punishment and avoidant type responses. More social control was perceived by highly identifying self-help group members. Educational responses were seen as used by groups more extensively than other responses. Punishment responses were mediated by the perceived costs an individual's relapse incurred on the rest of the group. These findings inform our understanding of what standards of normative and deviant behaviour self-help groups hold, and how they react to violations of such norms. They also have a number of implications for practitioners and facilitators in regard to using social identities as part of the treatment process.

  2. Privilege and status in an unequal society: shifting the focus of health promotion research to include the maintenance of advantage.

    Science.gov (United States)

    Stephens, Christine

    2010-10-01

    There has been a great deal of social policy and health promotion practice directed toward the inclusion of underprivileged groups with the aim of improving their health. This focus on disadvantaged people and poor communities, to help them empower themselves and improve their lot, often fails because it ignores the role of the broader society. We neglect to note the crucial part that the advantaged play in perpetuating inequalities. Theory and empirical work from sociology and anthropology points to the everyday ways in which privileged people are able to maintain their advantage and even hi-jack the benefits of public health programmes designed to improve the health of the poor. Some examples from these other disciplines suggest ways in which a social psychological perspective can contribute to an understanding of how inequalities and poverty are perpetuated in everyday life. These understandings will inform the effectiveness of social programmes to reduce inequalities.

  3. Current models of positive mental health

    Directory of Open Access Journals (Sweden)

    Stanojević Dragana Z.

    2012-01-01

    Full Text Available The concept of positive mental health represents not merely the absence of mental disease but presence of high level of happiness and well-being. In this paper we mentioned shortly the earliest concept of mental health, presented by Marie Jahoda in the mid-twentieth century. After that, we described two traditions in understanding and researching of subjective well-being: hedonic and eudaimonic approach. First approach focuses on investigation of positive affects and happiness as emotional and life satisfaction as cognitive component of subjective well-being. Second tradition emphasizes potentials and competences that person develops to the highest level, in personal and social area. Both psychological and social well-being are core concept of positive mental health psychology, designated together as positive functioning. The psychological well-being comprises six dimensions: self-acceptance, positive relations with others, environmental mastery, autonomy, purpose of life and personal growth. Social well-being consists of five dimensions: social integration, social acceptance, social contribution, social actualization and social coherence. By integrating hedonic and eudaimonic well-being as well as absence of mental disease, Corey Keyes introduced concept of complete mental health. People with complete mental health have reported absence of disease during past year and presence of high level of emotional, psychological and social well-being (flourishing. People with incomplete mental health have also reported absence of mental disease but low level of positive functioning (languishing. Keyes thought there are people with complete and incomplete mental illness; both groups report presence of mental disease, but second group has high level of positive functioning. Models of positive mental health are widely used in research studies as well as in programs for prevention and promotion of mental health. .

  4. Health care during reactor shut down for maintenance, inspection and repair of nuclear power plants in the Netherlands

    International Nuclear Information System (INIS)

    Wijker, H.

    1975-01-01

    The health care for workers in power plants has medical-biological aspects and physical-technical ones. It requires a close collaboration between the medical doctor and the health physicist. A combination of prevention, supervision and checks provides an optimumhealth care. It includes plant design, medical examination, whole body counting, radiological passports, dose reserve calculations, dose measurements, radiation supervision services, physical and medical checks. The discussion of the subjects comprises organization and experience in the Netherlands

  5. Community College Students' Health Insurance Enrollment, Maintenance, and Talking With Parents Intentions: An Application of the Reasoned Action Approach.

    Science.gov (United States)

    Huhman, Marian; Quick, Brian L; Payne, Laura

    2016-05-01

    A primary objective of health care reform is to provide affordable and quality health insurance to individuals. Currently, promotional efforts have been moderately successful in registering older, more mature adults yet comparatively less successful in registering younger adults. With this challenge in mind, we conducted extensive formative research to better understand the attitudes, subjective norms, and perceived behavioral control of community college students. More specifically, we examined how each relates to their intentions to enroll in a health insurance plan, maintain their current health insurance plan, and talk with their parents about their parents having health insurance. In doing so, we relied on the revised reasoned action approach advanced by Fishbein and his associates (Fishbein & Ajzen, 2010; Yzer, 2012, 2013). Results showed that the constructs predicted intentions to enroll in health insurance for those with no insurance and for those with government-sponsored insurance and intentions to maintain insurance for those currently insured. Our study demonstrates the applicability of the revised reasoned action framework within this context and is discussed with an emphasis on the practical and theoretical contributions.

  6. Training tomorrow's global health leaders: applying a transtheoretical model to identify behavior change stages within an intervention for health leadership development.

    Science.gov (United States)

    Daniels, Joseph; Farquhar, Carey; Nathanson, Neal; Mashalla, Yohana; Petracca, Frances; Desmond, Michelle; Green, Wendy; Davies, Luke; O'Malley, Gabrielle

    2014-12-01

    Training health professionals in leadership and management skills is a key component of health systems strengthening in low-resource settings. The importance of evaluating the effectiveness of these programs has received increased attention over the past several years, although such evaluations continue to pose significant challenges. This article presents evaluation data from the pilot year of the Afya Bora Fellowship, an African-based training program to increase the leadership capacity of health professionals. Firstly, we describe the goals of the Afya Bora Fellowship. Then, we present an adaptation of the transtheoretical model for behavior change called the Health Leadership Development Model, as an analytical lens to identify and describe evidence of individual leadership behavior change among training participants during and shortly after the pilot year of the program. The Health Leadership Development Model includes the following: pre-contemplation (status quo), contemplation (testing and internalizing leadership), preparation - (moving toward leadership), action (leadership in action), and maintenance (effecting organizational change). We used data from surveys, in-depth interviews, journal entries and course evaluations as data points to populate the Health Leadership Development Model. In the short term, fellows demonstrated increased leadership development during and shortly after the intervention and reflected the contemplation, preparation and action stages of the Health Leadership Development Model. However, expanded interventions and/or additional time may be needed to support behavior change toward the maintenance stages. We conclude that the Health Leadership Development Model is useful for informing health leadership training design and evaluation to contribute to sustainable health organizational change. © The Author(s) 2014.

  7. Maintenance in sustainable manufacturing

    Directory of Open Access Journals (Sweden)

    Vladimir Stuchly

    2014-09-01

    Full Text Available Background: Sustainable development is about reaching a balance between economic, social, and environmental goals, as well as people's participation in the planning process in order to gain their input and support. For a company, sustainable development means adoption of such business strategy and actions that contribute to satisfying present needs of company and stakeholders, as well as simultaneous protection, maintenance and strengthening of human and environmental potential which will be needed in the future. This new approach forces manufacturing companies to change their previous management paradigms. New management paradigm should include new issues and develop innovative methods, practices and technologies striving for solving problem of shortages of resources, softening environment overload and enabling development of environment-friendly lifecycle of products. Hence, its realization requires updating existing production models as they are based on previously accepted paradigm of unlimited resources and unlimited regeneration capabilities. Maintenance plays a crucial role because of its impact on availability, reliability, quality and life cycle cost, thus it should be one of the main pillars of new business running model.  Material and methods: The following paper is a result of research on the literature and observation of practices undertaken by a company within maintenance area. Results and conclusions: The main message is that considering sustainable manufacturing requires considerable expanding range of analysis and focusing on supporting processes. Maintenance offers numerous opportunities of decreasing influence of business processes on natural environment and more efficient resources utilization. The goal of maintenance processes realizing sustainable development strategy is increased profitability of exploitation and optimization of total lifecycle cost without disturbing safety and environmental issues. 

  8. The methods, models and information support on administrative decisions on medico-sanitary maintenance of population of Ukraine in the after Chernobyl accident period

    International Nuclear Information System (INIS)

    Torbin, V.; Babich, A.; Onopchuk, J.

    1996-01-01

    The liquidation of serious consequences of Chernobyl accident, taking into consideration their character and scale, requires the huge material and human resources. The complexity and plural of factors, affecting on planning and management of measures on medical-sanitarian maintenance of damaged population, requires the processing during acceptance of decisions, large files of information, containing parameters of healths condition of damaged population, information about the level of complex medical-sanitarian maintenance, dynamics of investments and compensation and etc. The instability of economic situation in Ukraine, connected with transition to new forms of managing and formation of political system does not permit to increase the resources on decisions the problems of liquidation of Chernobyl accident, requires the increasing the effectiveness, efficiency and qualities of accepted decisions on control and management of forming situation. (author)

  9. Estimating the impact of enterprise resource planning project management decisions on post-implementation maintenance costs: a case study using simulation modelling

    Science.gov (United States)

    Fryling, Meg

    2010-11-01

    Organisations often make implementation decisions with little consideration for the maintenance phase of an enterprise resource planning (ERP) system, resulting in significant recurring maintenance costs. Poor cost estimations are likely related to the lack of an appropriate framework for enterprise-wide pre-packaged software maintenance, which requires an ongoing relationship with the software vendor (Markus, M.L., Tanis, C., and Fenema, P.C., 2000. Multisite ERP implementation. CACM, 43 (4), 42-46). The end result is that critical project decisions are made with little empirical data, resulting in substantial long-term cost impacts. The product of this research is a formal dynamic simulation model that enables theory testing, scenario exploration and policy analysis. The simulation model ERPMAINT1 was developed by combining and extending existing frameworks in several research domains, and by incorporating quantitative and qualitative case study data. The ERPMAINT1 model evaluates tradeoffs between different ERP project management decisions and their impact on post-implementation total cost of ownership (TCO). Through model simulations a variety of dynamic insights were revealed that could assist ERP project managers. Major findings from the simulation show that upfront investments in mentoring and system exposure translate to long-term cost savings. The findings also indicate that in addition to customisations, add-ons have a significant impact on TCO.

  10. Methodology for Detecting Malfunctions and Evaluating the Maintenance Effectiveness in Wind Turbine Generator Bearings Using Generic versus Specific Models from SCADA Data

    Directory of Open Access Journals (Sweden)

    Miguel A. Rodríguez-López

    2018-03-01

    Full Text Available This article offers reasons to defend the use of generic behavior models as opposed to specific models in applications to determine component degradation. The term generic models refers to models based on operating data from various units, whereas specific models are calculated using operating data taken from a single unit. Moreover, generic models, used in combination with a status indicator, show excellent capacity for detecting anomalies in the equipment and for evaluating the effectiveness of the maintenance actions, resulting in lower development and maintenance costs for the operating firm. Artificial neural networks and moving means were used to calculate the degradation indicators, based on the remainders in the model. The models were developed from operating data from fourteen wind turbines monitored over several years, and applied to the detection of faults in the bearings on the non-drive end of the generator. The use of generic models may not be recommendable for detecting faults in all cases, and the suitability will depend greatly on the context of the methodology developed to detect each type of fault, according to the element causing the fault and the fault mode, since each methodology requires a greater or lesser degree of precision in the model.

  11. An Ontology Evolution and Maintenance Model in Web Environment%一种网络环境中的本体演化和维护模型

    Institute of Scientific and Technical Information of China (English)

    王进; 陈恩红; 林乐

    2003-01-01

    With the rapid development of Internet, Knowledge web will be one of development directions of the next generation of Internet. The applications of ontology will bring new opportunities and challenges to it. In this paper, we propose an ontology evolution and maintenance model in the Web environment to solve the conflicts and inconsistencies between domain ontologies and knowledge caused by the changes of the knowledge sources in the Web environment by extracting and analyzing the meta-data of the data sources.

  12. Maintenance, operation, and research (radiation) zones (MORZ) application model - a design and operation tool for intelligent buildings with application to the advanced neutron source

    International Nuclear Information System (INIS)

    Shapira, H.B.; Brown, R.A.

    1995-01-01

    This paper describes a user-friendly application tool to assist in the design, operation and maintenance of large buildings/facilities charged with complex/extensive/elaborate activities. The model centers around a specially designed, easy-access data base containing essentially all the relevant information about the facility. Our first test case is the Advanced Neutron Source (ANS) research reactor to be constructed as a center for neutron research

  13. Creating Flexible and Sustainable Work Models for Academic Obstetrician-Gynecologists Engaged in Global Health Work.

    Science.gov (United States)

    Molina, Rose; Boatin, Adeline; Farid, Huma; Luckett, Rebecca; Neo, Dayna; Ricciotti, Hope; Scott, Jennifer

    2017-10-01

    To describe various work models for obstetrics and gynecology global health faculty affiliated with academic medical centers and to identify barriers and opportunities for pursuing global health work. A mixed-methods study was conducted in 2016 among obstetrics and gynecology faculty and leaders from seven academic medical institutions in Boston, Massachusetts. Global health faculty members were invited to complete an online survey about their work models and to participate in semistructured interviews about barriers and facilitators of these models. Department chairs and residency directors were asked to participate in interviews. The survey response rate among faculty was 65.6% (21/32), of which 76.2% (16/21) completed an interview. Five department leaders (45.5% [5/11]) participated in an interview. Faculty described a range of work models with varied time and compensation, but only one third reported contracted time for global health work. The most common barriers to global health work were financial constraints, time limitations, lack of mentorship, need for specialized training, and maintenance of clinical skills. Career satisfaction, creating value for the obstetrics and gynecology department, and work model flexibility were the most important facilitators of sustainable global health careers. The study identified challenges and opportunities to creating flexible and sustainable work models for academic obstetrics and gynecology clinicians engaged in global health work. Additional research and innovation are needed to identify work models that allow for sustainable careers in global women's health. There are opportunities to create professional standards and models for academic global health work in the obstetrics and gynecology specialty.

  14. Model Integrasi Penjadwalan Batch dan Penjadwalan Preventive Maintenance dengan Kriteria Minimisasi Biaya Simpan, Biaya Setup, Biaya Pm, serta Biaya Rework pada Mesin Stabil

    Directory of Open Access Journals (Sweden)

    Zahedi Zahedi

    2014-06-01

    Full Text Available This study developed a model of batch scheduling involving the unavailability machine to minimize setup costs, cost of preventive maintenance and the cost of rework in a stable machine. This model is considered necessary in order to understand the effect of the unavailability machine for production runs and to understand the effect on the batch production schedule. The results of this study indicate that the first and last run will not give single batch. Given a hypothetical example of how the model and algorithm developed solve the problem instance. 

  15. 26 CFR 1.420-1 - Significant reduction in retiree health coverage during the cost maintenance period.

    Science.gov (United States)

    2010-04-01

    ... sale or other transfer in connection with which the employees of a trade or business of the employer... of the trade or business. (d) Examples. The following examples illustrate the application of this... individuals died in Year 2. During Year 3, Employer W amends its health plan to eliminate coverage for 5...

  16. Model of Management (Mo.Ma) for the patient with schizophrenia: crisis control, maintenance, relapse prevention, and recovery with long-acting injectable antipsychotics (LAIs).

    Science.gov (United States)

    Brugnoli, Roberto; Rapinesi, Chiara; Kotzalidis, Georgios D; Marcellusi, Andrea; Mennini, Francesco S; De Filippis, Sergio; Carrus, Dario; Ballerini, Andrea; Francomano, Antonio; Ducci, Giuseppe; Del Casale, Antonio; Girardi, Paolo

    2016-01-01

    Schizophrenia is a severe mental disease that affects approximately 1% of the population with a relevant chronic impact on social and occupational functioning and daily activities. People with schizophrenia are 2-2.5 times more likely to die early than the general population. Non-adherence to antipsychotic medications, both in chronic and first episode schizophrenia, is one of the most important risk factors for relapse and hospitalization, that consequently contributes to increased costs due to psychiatric hospitalization. Atypical long-acting injectable (LAI) antipsychotics can improve treatment adherence and decrease re-hospitalization rates in patients with schizophrenia since its onset. The primary goals in the management of schizophrenia are directed not only at symptom reduction in the short and long term, but also at maintaining physical and mental functioning, improving quality of life, and promoting patient recovery. To propose a scientific evidence-based integrated model that provides an algorithm for recovery of patients with schizophrenia and to investigate the effectiveness and safety of antipsychotics LAI in the treatment, maintenance, relapse prevention, and recovery of schizophrenia. After an accurate literature review we identified, collected and analyzed the crucial points in taking care schizophrenia patients, through which we defined the steps described in the model of management and the choice of the better treatment option. Results. In the management model we propose, the choice of a second generation long acting antipsychotic, could allow from the earliest stages of illness better patient management, especially for young individuals with schizophrenia onset, a better recovery and significant reductions of relapse and health care costs. LAI formulations of antipsychotics are valuable, because they help patients to remain adherent to their medication through regular contact with healthcare professionals and to prevent covert non-adherence. The

  17. Probabilistic risk analysis of aging components which fail on demand. A Bayesian model. Application to maintenance optimization of Diesel engine linings

    International Nuclear Information System (INIS)

    Procaccia, H.; Lannoy, A.; Clarotti, C.A.

    1997-01-01

    The optimization of preventive maintenance of aging materials can be well modelled through the application of the two-parameters Weibull law. Unfortunately there is no theoretical model describing the aging of components implied in emergency interventions which may fail in very moment of demand. These components are relevant to the safety of Nuclear Power Plants and the main problem with them is the optimization of the maintenance and the test schedule. Indeed the effect of any test is twofold, namely: the test reveals failures which otherwise would occur when the Power Plant would need urgent intervention but at the same time it causes the aging process to step up. The aging process is suspected to affect certain safeguard equipment, but it does not exist a theoretical model of component aging in function of demands. Sections 2.1 and 2.2 of the paper are devoted to the description of a Bayesian model of discrete aging, deriving the likelihood function of the model (data modelling) and to selecting 'the best prior' (Analyst knowledge) that can be associated to the likelihood, respectively. The aspects of numerical integration relative to assessing the predictive reliability of the aging components are discussed in Section 2.3. Section 3 reports a Reliability Centered Maintenance application of the model to cylinders of emergency electrical generators of the NPP nuclear sectors. These components are subjected to an annual endoscopic checking and to a systematical replacement at every 5 years. The statistical Bayesian decision theory was applied to determine an optimal period of cylinder replacement based on the aging model presented in this paper. It is shown that the optimal value is between 10 to 12 years. (author)

  18. On models of health assistance and the program of family health of the Brazilian Health Department

    Directory of Open Access Journals (Sweden)

    Claudia Hausman Silveira

    2008-08-01

    Full Text Available The article makes reference to the three models that have inspired the construction of the Program of Family Health in Brazil (Cuban, English and Canadian, observing their differences and similarities and comparing them with the Brazilian case. Therefore, an associative line is also constructed between the Only System of Health (SUS and the necessity of a practice which allows the functioning of its lines of direction and organization principles. Thus, we reach the conclusion that the Program of Family Health in Brazil, for its multi professional work proposal in interdisciplinary teams, in accordance with the SUS, can help keep the law of health in the Country. Key-words: SUS; Program of Family Health; Interdisciplinary; Medical care model; Sanitary practice

  19. Assessing the co-benefits of greenhouse gas reduction: Health benefits of particulate matter related inspection and maintenance programs in Bangkok, Thailand

    International Nuclear Information System (INIS)

    Li, Ying; Crawford-Brown, Douglas J.

    2011-01-01

    the expenditures on policy implementation. - Research Highlights: → Health benefits are important co-benefits of greenhouse gas reduction. → We quantify the health benefits of inspection and maintenance programs in Bangkok. → The programs could yield substantial health benefits relative to business-as-usual. → The benefits considerably outweigh the expenditures on policy implementation.

  20. Propuesta de un modelo de gestión de mantenimiento y sus principales herramientas de apoyo Proposal of a maintenance management model and its main support tools

    Directory of Open Access Journals (Sweden)

    Pablo Viveros

    2013-04-01

    Full Text Available Este artículo presenta un modelo para la gestión integral del mantenimiento, teniendo en consideración la característica de mejora continua en el tiempo. A modo de introducción y contextualización, se explica la importancia que tiene la alineación de objetivos a todo nivel organizacional para lograr la integración y correcta gestión de la unidad de mantenimiento. El modelo a presentar se compone de siete principales etapas, las cuales deben desarrollarse progresivamente según el escenario actual de la organización, haciendo énfasis en la gestión y optimización sostenida en el tiempo de procesos asociados a la planificación, programación y ejecución del mantenimiento. Adicionalmente, el modelo presentado complementa herramientas de apoyo para el desarrollo e implementación de las etapas, y características operacionales reales, las cuales podrían afectar el desempeño de la unidad de mantenimiento. Finalmente, se presentan algunas consideraciones generales y respectivas conclusiones.This paper presents a model for the integrated management of maintenance, taking into account features of continuous improvement over time. As an introduction and contextualization, it explains the importance of aligning organizational goals at all levels in order to achieve proper integration and management of the maintenance unit. The present model consists of seven main stages, which must be progressively implemented depending on the current scenario of the organization, focusing on management and sustained over time optimization of processes related to planning, programming and maintenance execution. Additionally, the model presented is supported by tools to develop and implement the stages, and provides a real operational context of the industrial maintenance management; which may affect performance. Finally, we present some general considerations and conclusions.

  1. Assessing maintenance contracts when preventive maintenance is outsourced

    International Nuclear Information System (INIS)

    Wu Shaomin

    2012-01-01

    In some companies, corrective maintenance is conducted in-house but preventive maintenance might be outsourced. This raises a need to optimise some parameters such as the number of contracts from a perspective of the equipment owner. This paper considers a maintenance policy for such a situation, analyses the roles of the parameters in a PM model, proposes approaches to defining bonus functions, and finally discusses special cases of both the PM policy and the bonus function. Numerical examples are also given to explore the impact of parameters on the expected lifecycle cost rate.

  2. Maintenance Business Plans.

    Science.gov (United States)

    Adams, Matt

    2002-01-01

    Discusses maintenance business plans, statements which provide accountability for facilities maintenance organizations' considerable budgets. Discusses the plan's components: statement of plan objectives, macro and detailed description of the facility assets, maintenance function descriptions, description of key performance indicators, milestone…

  3. Maintenance Management Update.

    Science.gov (United States)

    Sternloff, Robert E.

    1987-01-01

    Current trends in park maintenance are overviewed, including maintenance impact statements, avoidance of cost through efficient use and national resource conservation, horticultural accomplishments that influence maintenance management, and vandalism prevention. (CB)

  4. [A PARADIGM SHIFT IN THE PERCEPTION OF HEALTH MAINTENANCE FROM INCREASING PHYSICAL ACTIVITY TO DECREASING PHYSICAL INACTIVITY].

    Science.gov (United States)

    Rotman, Dani; Constantini, Naama

    2016-06-01

    Modern man spends most of his waking hours (50-70%) in one form or another of sedentary behavior, defined as activity conducted in a sitting or reclining position involving low energy expenditure. The remaining waking hours are spent performing low intensity physical activity (25-45%) and medium-high intensity physical activity (less than 5%): Despite this distribution, medical research has focused on the impact of increasing medium-high intensity physical activity and many health organizations' recommendations are in accordance. In recent years, research conducted has begun to examine the effect inactivity has on health and has shown that excess sedentary behaviour is an independent risk factor for a wide range of medical problems such as obesity, metabolic syndrome, poor cardiovascular health profile, diabetes mellitus, and possibly cancer. Although the higher risk brought on by sedentary behaviour is partially reduced by increasing medium-high intensity physical activity, it is not completely neutralized. One way to diminish the harm caused by long hours of sitting is to take short breaks during periods of prolonged sitting in order to walk. According to these findings, it is worthwhile to recommend reducing the hours spent in sedentary behaviour, or at least to take frequent short breaks ("activity snacks") during periods of prolonged sitting to get up and walk around.

  5. Fault Diagnosis approach based on a model-based reasoner and a functional designer for a wind turbine. An approach towards self-maintenance

    Science.gov (United States)

    Echavarria, E.; Tomiyama, T.; van Bussel, G. J. W.

    2007-07-01

    The objective of this on-going research is to develop a design methodology to increase the availability for offshore wind farms, by means of an intelligent maintenance system capable of responding to faults by reconfiguring the system or subsystems, without increasing service visits, complexity, or costs. The idea is to make use of the existing functional redundancies within the system and sub-systems to keep the wind turbine operational, even at a reduced capacity if necessary. Re-configuration is intended to be a built-in capability to be used as a repair strategy, based on these existing functionalities provided by the components. The possible solutions can range from using information from adjacent wind turbines, such as wind speed and direction, to setting up different operational modes, for instance re-wiring, re-connecting, changing parameters or control strategy. The methodology described in this paper is based on qualitative physics and consists of a fault diagnosis system based on a model-based reasoner (MBR), and on a functional redundancy designer (FRD). Both design tools make use of a function-behaviour-state (FBS) model. A design methodology based on the re-configuration concept to achieve self-maintained wind turbines is an interesting and promising approach to reduce stoppage rate, failure events, maintenance visits, and to maintain energy output possibly at reduced rate until the next scheduled maintenance.

  6. Fault Diagnosis approach based on a model-based reasoner and a functional designer for a wind turbine. An approach towards self-maintenance

    International Nuclear Information System (INIS)

    Echavarria, E; Tomiyama, T; Bussel, G J W van

    2007-01-01

    The objective of this on-going research is to develop a design methodology to increase the availability for offshore wind farms, by means of an intelligent maintenance system capable of responding to faults by reconfiguring the system or subsystems, without increasing service visits, complexity, or costs. The idea is to make use of the existing functional redundancies within the system and sub-systems to keep the wind turbine operational, even at a reduced capacity if necessary. Re-configuration is intended to be a built-in capability to be used as a repair strategy, based on these existing functionalities provided by the components. The possible solutions can range from using information from adjacent wind turbines, such as wind speed and direction, to setting up different operational modes, for instance re-wiring, re-connecting, changing parameters or control strategy. The methodology described in this paper is based on qualitative physics and consists of a fault diagnosis system based on a model-based reasoner (MBR), and on a functional redundancy designer (FRD). Both design tools make use of a function-behaviour-state (FBS) model. A design methodology based on the re-configuration concept to achieve self-maintained wind turbines is an interesting and promising approach to reduce stoppage rate, failure events, maintenance visits, and to maintain energy output possibly at reduced rate until the next scheduled maintenance

  7. EFSA Panel on Dietetic Products, Nutrition and Allergies; Scientific Opinion on the substantiation of a health claim related to collagen hydrolysate and maintenance of joints pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following an application from Gelita AG, submitted via the Competent Authority of Germany, the Panel on Dietetic Products, Nutrition and Allergies was asked to deliver an opinion on the scientific substantiation of a health claim related to collagen hydrolysate and maintenance of joint health...... hydrolysate is sufficiently characterised. The claimed effect is “maintenance of joint health”. The target population as proposed by the applicant is physically active people. The Panel considers that the maintenance of joints is a beneficial physiological effect. The applicant provided one narrative review...... was not controlled and no scientific conclusions could be drawn from these studies for the substantiation of the claimed effect. One trial in 147 active student athletes evaluated a total of 15 parameters related to joint pain/discomfort. There were no significant differences between groups for any endpoint when...

  8. Tofacitinib in Patients with Ulcerative Colitis: Health-Related Quality of Life in Phase 3 Randomised Controlled Induction and Maintenance Studies.

    Science.gov (United States)

    Panés, Julian; Vermeire, Séverine; Lindsay, James O; Sands, Bruce E; Su, Chinyu; Friedman, Gary; Zhang, Haiying; Yarlas, Aaron; Bayliss, Martha; Maher, Stephen; Cappelleri, Joseph C; Bushmakin, Andrew G; Rubin, David T

    2018-01-24

    Tofacitinib is an oral, small molecule Janus kinase [JAK] inhibitor that is being investigated for ulcerative colitis [UC]. We evaluated health-related quality of life [HRQoL] in tofacitinib UC Phase 3 studies. Patients ≥ 18 years old in OCTAVE Induction 1 [N = 598] and 2 [N = 541] with moderately to severely active UC were randomised [1:4] to placebo or tofacitinib 10 mg twice daily [BID] for 8 weeks. Subsequently, OCTAVE Sustain re-randomised [1:1:1] clinical responders [N = 593] from induction studies to placebo, tofacitinib 5 mg BID, or 10 mg BID, for 52 weeks. Inflammatory Bowel Disease Questionnaire [IBDQ] and SF-36v2® Health Survey [SF-36v2] assessed HRQoL. In OCTAVE Induction 1 and 2, mean changes from baseline IBDQ were greater with tofacitinib 10 mg BID at Week 8 [28.9 and 31.5] versus placebo [15.4 and 17.2; p tofacitinib 5 mg [-1.3] and 10 mg BID [0.6], and larger with placebo [-20.2; p Tofacitinib 10 mg BID induction therapy significantly improved HRQoL versus placebo at Week 8. Improvements were maintained through 52 weeks' maintenance therapy with tofacitinib 5 mg and 10 mg BID. NCT01465763, NCT01458951 and NCT01458574. © European Crohn’s and Colitis Organisation (ECCO) 2017.

  9. Cultural factors related to the maintenance of health behaviours in Algonquin women with a history of gestational diabetes.

    Science.gov (United States)

    Gaudreau, S; Michaud, C

    2012-06-01

    Though the cultural factors that may contribute to the diabetes epidemic in First Nations are frequently discussed, little is known about the factors that may help prevent it. In this ethnonursing study, we explore the cultural factors that help maintain health behaviours in Algonquin women who had received a diagnosis of gestational diabetes 2 to 10 years before this study. The data were collected in two Algonquin communities through semi-structured interviews with key informants (n = 7) and general informants (n = 8) and through cultural immersion, with detailed observations being recorded into logbooks. The cultural factors that are likely to affect the prevention of diabetes are the importance of family and social ties, the possibility of preserving cultural values, the opportunity to learn behaviours through educational resources adapted to needs and culture, the chance of saving money through better diet and access to blood sugar data as a means of control. In the long term, these cultural factors could influence health behaviours and thus help prevent type 2 diabetes.

  10. Screening and monitoring of main diseases a modern strategy of health maintenance in personnel of radiation dangerous plants

    International Nuclear Information System (INIS)

    Takhauov, R. M.; Karpov, A. B.; Kubat, I. I.; Maslyuk, A. I.; Semenova, Y. V.; Freidin, M. B.; Trivozhenko, A. B.; Litvinenko, T. M.

    2004-01-01

    Population health is greatly determined by social factors, mode of life, ecological situation, amount and quality of medical assistance. The analysis of reasons of health troubles increase in population should be done taking into account the above aspects. Main consideration should be given to the development of measures aimed at the highest possible decrease of technogenic and anthropogenic factors influence on a human. Thereupon a complex programme of main diseases screening and monitoring in the personnel of the Siberian Group of Chemical enterprises (SGCE) to be the biggest one among Russian atomic plants has been developed. The purpose of the present paper is to determine main diseases at the earliest stage, the decrease of death rate, as well as the complex estimation of technogenic factor influence on the personnel of radiation dangerous plants nand their offsprings. In this case a long-term effect of low doses seems to be the main risk factor. Taking into account the structure of death rate causes of the population of industrialized countries as well as the spectrum of stochastic effects of ionizing radiation, the screening of cardiac ischemia and arterial hypertension, localization of cancer and congenital malformations have been chosen as the program priorities. Algorithm of instrumental laboratory screening of a particular disease includes modern diagnostic tests. Groups ar risk are formed taking into account a complex of exogenous and endogenous risk factors (age, chronic diseases, bad habits, length of service at a radiation dangerous plant, dose loads, hereditary factors) and on the basis of the screening examination results. The information obtained is entered in the list of database of the Regional Medico dosimetric Register of the SGCE personnel and Seversk residents followed by analysis and monitoring of groups ar risk. (Author) 4 refs

  11. Software Maintenance Management Evaluation and Continuous Improvement

    CERN Document Server

    April, Alain

    2008-01-01

    This book explores the domain of software maintenance management and provides road maps for improving software maintenance organizations. It describes full maintenance maturity models organized by levels 1, 2, and 3, which allow for benchmarking and continuous improvement paths. Goals for each key practice area are also provided, and the model presented is fully aligned with the architecture and framework of software development maturity models of CMMI and ISO 15504. It is complete with case studies, figures, tables, and graphs.

  12. Views of policy makers and health promotion professionals on factors facilitating implementation and maintenance of interventions and policies promoting physical activity and healthy eating: results of the DEDIPAC project.

    Science.gov (United States)

    Muellmann, Saskia; Steenbock, Berit; De Cocker, Katrien; De Craemer, Marieke; Hayes, Catherine; O'Shea, Miriam P; Horodyska, Karolina; Bell, Justyna; Luszczynska, Aleksandra; Roos, Gun; Langøien, Lars Jørun; Rugseth, Gro; Terragni, Laura; De Bourdeaudhuij, Ilse; Brug, Johannes; Pischke, Claudia R

    2017-12-06

    The uptake, implementation, and maintenance of effective interventions promoting physical activity (PA) and a healthy diet and the implementation of policies targeting these behaviors are processes not well understood. We aimed to gain a better understanding of what health promotion professionals and policy makers think are important factors facilitating adoption, implementation, and maintenance of multi-level interventions and policies promoting healthy eating and PA in Belgium, Germany, Ireland, Norway, and Poland. Six interventions and six policies were identified based on pre-defined criteria. Forty semi-structured interviews were conducted with stakeholders from various sectors to elicit information on factors impacting adoption, implementation, and maintenance of these interventions and policies. All interview transcripts were coded in NVivo, using a common categorization matrix. Coding in the respective countries was done by one researcher and validated by a second researcher. Active involvement of relevant stakeholders and good communication between coordinating organizations were described as important factors contributing to successful adoption and implementation of both interventions and policies. Additional facilitating factors included sufficient training of staff and tailoring of materials to match needs of various target groups. The respondents indicated that maintenance of implemented interventions/policies depended on whether they were embedded in existing or newly created organizational structures in different settings and whether continued funding was secured. Despite considerable heterogeneity of interventions and health policies in the five countries, stakeholders across these countries identify similar factors facilitating adoption, implementation, and maintenance of these interventions and policies.

  13. Gym-based exercise was more costly compared with home-based exercise with telephone support when used as maintenance programs for adults with chronic health conditions: cost-effectiveness analysis of a randomised trial

    Directory of Open Access Journals (Sweden)

    Paul Jansons

    2018-01-01

    Registration: ACTRN12610001035011. [Jansons P, Robins L, O’Brien L, Haines T (2018 Gym-based exercise was more costly compared with home-based exercise with telephone support when used as maintenance programs for adults with chronic health conditions: cost-effectiveness analysis of a randomised trial. Journal of Physiotherapy 64: 48–54

  14. Gym-based exercise and home-based exercise with telephone support have similar outcomes when used as maintenance programs in adults with chronic health conditions: a randomised trial

    Directory of Open Access Journals (Sweden)

    Paul Jansons

    2017-07-01

    Trial registration: ACTRN12610001035011. [Jansons P, Robins L, O’Brien L, Haines T (2017 Gym-based exercise and home-based exercise with telephone support have similar outcomes when used as maintenance programs in adults with chronic health conditions: a randomised trial. Journal of Physiotherapy 63: 154–160

  15. TECHNICAL MAINTENANCE EFFICIENCY OF THE AIRCRAFT MAINTENANCE-FREE ON-BOARD SYSTEM BETWEEN SCHEDULED MAINTENANCES

    Directory of Open Access Journals (Sweden)

    A. M. Bronnikov

    2017-01-01

    Full Text Available The avionics concept of the maintenance-free on-board equipment implies the absence of necessity to maintain onboard systems between scheduled maintenance, preserving the required operational and technical characteristics; it should be achieved by automatic diagnosis of the technical condition and the application of active means of ensuring a failsafe design, allowing to change the structure of the system to maintain its functions in case of failure. It is supposed that such equipment will reduce substantially and in the limit eliminate traditional maintenance of aircraft between scheduled maintenance, ensuring maximum readiness for use, along with improving safety. The paper proposes a methodology for evaluating the efficiency of maintenance-free between scheduled maintenance aircraft system with homogeneous redundancy. The excessive redundant elements allow the system to accumulate failures which are repaired during the routine maintenance. If the number of failures of any reserve is approaching a critical value, the recovery of the on-board system (elimination of all failures is carried out between scheduled maintenance by conducting rescue and recovery operations. It is believed that service work leads to the elimination of all failures and completely updates the on-board system. The process of system operational status changes is described with the discrete-continuous model in the flight time. The average losses in the sorties and the average cost of operation are used as integrated efficiency indicators of system operation. For example, the evaluation of the operation efficiency of formalized on-board system with homogeneous redundancy demonstrates the efficiency of the proposed methodology and the possibility of its use while analyzing the efficiency of the maintenance-free operation equipment between scheduled periods. As well as a comparative analysis of maintenance-free operation efficiency of the on-board system with excessive

  16. An Innovative School Health Education Model Designed for Student Achievement.

    Science.gov (United States)

    Rohwer, John; Wandberg, Bob

    New threats to the health of American children, often psychosocial in nature due to societal changes, must be addressed. The Minnesota School Health Education Model is based on the integration of four primary components: (1) school health education goals aimed at health promotion, disease prevention, and long-term positive health effects on…

  17. A practical procedure for the selection of time-to-failure models based on the assessment of trends in maintenance data

    International Nuclear Information System (INIS)

    Louit, D.M.; Pascual, R.; Jardine, A.K.S.

    2009-01-01

    Many times, reliability studies rely on false premises such as independent and identically distributed time between failures assumption (renewal process). This can lead to erroneous model selection for the time to failure of a particular component or system, which can in turn lead to wrong conclusions and decisions. A strong statistical focus, a lack of a systematic approach and sometimes inadequate theoretical background seem to have made it difficult for maintenance analysts to adopt the necessary stage of data testing before the selection of a suitable model. In this paper, a framework for model selection to represent the failure process for a component or system is presented, based on a review of available trend tests. The paper focuses only on single-time-variable models and is primarily directed to analysts responsible for reliability analyses in an industrial maintenance environment. The model selection framework is directed towards the discrimination between the use of statistical distributions to represent the time to failure ('renewal approach'); and the use of stochastic point processes ('repairable systems approach'), when there may be the presence of system ageing or reliability growth. An illustrative example based on failure data from a fleet of backhoes is included.

  18. A practical procedure for the selection of time-to-failure models based on the assessment of trends in maintenance data

    Energy Technology Data Exchange (ETDEWEB)

    Louit, D.M. [Komatsu Chile, Av. Americo Vespucio 0631, Quilicura, Santiago (Chile)], E-mail: rpascual@ing.puc.cl; Pascual, R. [Centro de Mineria, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, Santiago (Chile); Jardine, A.K.S. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, Ont., M5S 3G8 (Canada)

    2009-10-15

    Many times, reliability studies rely on false premises such as independent and identically distributed time between failures assumption (renewal process). This can lead to erroneous model selection for the time to failure of a particular component or system, which can in turn lead to wrong conclusions and decisions. A strong statistical focus, a lack of a systematic approach and sometimes inadequate theoretical background seem to have made it difficult for maintenance analysts to adopt the necessary stage of data testing before the selection of a suitable model. In this paper, a framework for model selection to represent the failure process for a component or system is presented, based on a review of available trend tests. The paper focuses only on single-time-variable models and is primarily directed to analysts responsible for reliability analyses in an industrial maintenance environment. The model selection framework is directed towards the discrimination between the use of statistical distributions to represent the time to failure ('renewal approach'); and the use of stochastic point processes ('repairable systems approach'), when there may be the presence of system ageing or reliability growth. An illustrative example based on failure data from a fleet of backhoes is included.

  19. A multi-objective optimization model for energy-efficiency building envelope retrofitting plan with rooftop PV system installation and maintenance

    International Nuclear Information System (INIS)

    Fan, Yuling; Xia, Xiaohua

    2017-01-01

    Highlights: • A multi-objective optimization model for building envelope retrofit is presented. • Facility performance degradation and maintenance is built into the model. • A rooftop PV system is introduced to produce electricity. • Economic factors including net present value and payback period are considered. - Abstract: Retrofitting existing buildings with energy-efficient facilities is an effective method to improve their energy efficiency, especially for old buildings. A multi-objective optimization model for building envelope retrofitting is presented. Envelope components including windows, external walls and roofs are considered to be retrofitted. Installation of a rooftop solar panel system is also taken into consideration in this study. Rooftop solar panels are modeled with their degradation and a maintenance scheme is studied for sustainability of energy and its long-term effect on the retrofitting plan. The purpose is to make the best use of financial investment to maximize energy savings and economic benefits. In particular, net present value, the payback period and energy savings are taken as the main performance indicators of the retrofitting plan. The multi-objective optimization problem is formulated as a non-linear integer programming problem and solved by a weighted sum method. Results of applying the designed retrofitting plan to a 50-year-old building consisting of 66 apartments demonstrated the effectiveness of the proposed model.

  20. 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

  1. Maintenance of Fish Health in Aquaculture: Review of Epidemiological Approaches for Prevention and Control of Infectious Disease of Fish.

    Science.gov (United States)

    Assefa, Ayalew; Abunna, Fufa

    2018-01-01

    Aquaculture is rapidly growing part of agriculture worldwide. It makes up around 44 percent of total fish production globally. This increased growth of production is achieved despite facing many challenges in the aquaculture environment. Among production limiting challenges, the infectious disease takes the lion share by causing multibillion-dollar loss annually. To reduce the impact of the fish disease, it is necessary to address health constraints based on scientifically proven and recommended ways. This review aims at pointing out some of the best approaches to prevention and control of infectious disease in aquaculture. Among the effective prevention and control strategies, vaccination is one of the key practices. Types of vaccines for use in fish include killed vaccines, attenuated vaccines, DNA vaccines, recombinant technology vaccines, and synthetic peptide vaccines. Administration techniques of vaccines in fish include oral, injection, or immersion methods. Antibiotics are also in use in aquaculture despite their side effects in the development of drug resistance by microorganisms. Biological and chemical disease control strategies such as using probiotics, prebiotics, and medicinal plants are widely in use. Biosecurity measures in aquaculture can keep the safety of a facility from certain disease-causing agents that are absent in particular system. Farm-level biosecurity measures include strict quarantine measures, egg disinfection, traffic control, water treatments, clean feed, and disposal of mortalities. In conclusion, rather than trying to treat every disease case, it advisable to follow a preventive approach before the event of any disease outbreaks.

  2. Maintenance of Fish Health in Aquaculture: Review of Epidemiological Approaches for Prevention and Control of Infectious Disease of Fish

    Directory of Open Access Journals (Sweden)

    Ayalew Assefa

    2018-01-01

    Full Text Available Aquaculture is rapidly growing part of agriculture worldwide. It makes up around 44 percent of total fish production globally. This increased growth of production is achieved despite facing many challenges in the aquaculture environment. Among production limiting challenges, the infectious disease takes the lion share by causing multibillion-dollar loss annually. To reduce the impact of the fish disease, it is necessary to address health constraints based on scientifically proven and recommended ways. This review aims at pointing out some of the best approaches to prevention and control of infectious disease in aquaculture. Among the effective prevention and control strategies, vaccination is one of the key practices. Types of vaccines for use in fish include killed vaccines, attenuated vaccines, DNA vaccines, recombinant technology vaccines, and synthetic peptide vaccines. Administration techniques of vaccines in fish include oral, injection, or immersion methods. Antibiotics are also in use in aquaculture despite their side effects in the development of drug resistance by microorganisms. Biological and chemical disease control strategies such as using probiotics, prebiotics, and medicinal plants are widely in use. Biosecurity measures in aquaculture can keep the safety of a facility from certain disease-causing agents that are absent in particular system. Farm-level biosecurity measures include strict quarantine measures, egg disinfection, traffic control, water treatments, clean feed, and disposal of mortalities. In conclusion, rather than trying to treat every disease case, it advisable to follow a preventive approach before the event of any disease outbreaks.

  3. Preventive maintenance and reliability-centered maintenance

    International Nuclear Information System (INIS)

    Anderson, J.G.

    1989-01-01

    In the recent past, the primary function of the preventive maintenance program at a nuclear power plant was to maintain the operability and reliability of the plant. Reducing overall maintenance costs by performing effective preventive maintenance, instead of more costly and disruptive corrective maintenance, instead of more costly and disruptive corrective maintenance, was a secondary consideration. In today's operating environment, the preventive maintenance program must meet the test of cost-effectiveness as well as many new standards for performance that are being required by rate regulators. The preventive maintenance program must be able to withstand the challenge of independent audit to a new standard of technical adequacy and compliance with recommendations from component vendors. In this new environment, the standard that is being applied at the San Onofre nuclear generating station (SONGS) is that the preventive maintenance program must meet the test of cost-effectiveness, improve equipment performance, support increased plant availability, and (a) literally implement the recommendations of the vendor, (b) provide other compensation for the vendor recommendation, or (c) provide technical justification for the deviation. The subject of this paper is the way that reliability-centered maintenance (RCM) is helping SONGS meet these challenges

  4. Health Insurance, Medical Care, and Health Outcomes: A Model of Elderly Health Dynamics

    Science.gov (United States)

    Yang, Zhou; Gilleskie, Donna B.; Norton, Edward C.

    2009-01-01

    Prescription drug coverage creates a change in medical care consumption, beyond standard moral hazard, arising both from the differential cost-sharing and the relative effectiveness of different types of care. We model the dynamic supplemental health insurance decisions of Medicare beneficiaries, their medical care demand, and subsequent health…

  5. The modelling of health effects in COSYMA

    International Nuclear Information System (INIS)

    Ehrhardt, J.; Steinhauer, C.

    1991-01-01

    The presentation gives a brief overview of the types of health effects considered in each of the three subsystems of COSYMA, the way that the corresponding models are implemented and their present default parameter values. The risk of early effects is calculated using hazard functions, as recently recommended by US Nuclear Regulatory Commission and NRPB. The early fatal effects specified in COSYMA comprise those following the irradiation of the bone marrow (hematopoietic syndrome), the lung (pulmonary syndrome), the GI-tract (gastrointestinal syndrome) and skin (skin burns). In addition the mortality of pre-and neonates after exposure in utero is quantified. Of the possible non-fatal effects the only ones included are those which lead to a severe disability of the affected person for the rest of their life or which require medical treatment and/or social care

  6. Public health component in building information modeling

    Science.gov (United States)

    Trufanov, A. I.; Rossodivita, A.; Tikhomirov, A. A.; Berestneva, O. G.; Marukhina, O. V.

    2018-05-01

    A building information modelling (BIM) conception has established itself as an effective and practical approach to plan, design, construct, and manage buildings and infrastructure. Analysis of the governance literature has shown that the BIM-developed tools do not take fully into account the growing demands from ecology and health fields. In this connection, it is possible to offer an optimal way of adapting such tools to the necessary consideration of the sanitary and hygienic specifications of materials used in construction industry. It is proposed to do it through the introduction of assessments that meet the requirements of national sanitary standards. This approach was demonstrated in the case study of Revit® program.

  7. An integrated motivational interviewing and cognitive-behavioural intervention promoting physical activity maintenance for adults with chronic health conditions: A feasibility study.

    Science.gov (United States)

    Scott, Sarah E; Breckon, Jeff D; Copeland, Robert J

    2018-01-01

    Objectives Physical activity is recommended for managing chronic health conditions but is rarely maintained. This feasibility study aimed to evaluate the preliminary efficacy of a motivational interviewing and cognitive-behavioural intervention for long-term physical activity for adults with chronic health conditions. Methods Participants ( N = 37) with stable conditions (e.g. diabetes) were randomized into a three-month motivational interviewing and cognitive-behavioural group ( N = 20) or usual care ( N = 17) after completing a physical activity referral scheme. Participants completed physical activity (e.g. average steps per day and kilocalorie expenditure), psychological (e.g. self-efficacy) and epidemiological (e.g. body mass index) standardized measures at baseline, three- and six-month follow-up. Treatment fidelity and feasibility were assessed. Results Thirty-five participants completed the study (96% retention). The motivational interviewing and cognitive-behavioural group maintained kilocalorie expenditure at three ( p = 0.009) and six months ( p = 0.009). Exercise barrier self-efficacy ( p = 0.03), physical ( p = 0.02) and psychological ( p = 0.01) physical activity experiences were increased at three months only. No difference was found for average steps/day, social support, coping skills and epidemiological factors. Discussion This is the first study to demonstrate the feasibility and preliminary efficacy of motivational interviewing and cognitive-behavioural interventions for promoting physical activity maintenance in a clinical population. A large-scale trial with a longer follow-up (≥6 months) is warranted with treatment fidelity assessment.

  8. Impacts of inhomogeneous landscapes in oasis interior on the oasis self-maintenance mechanism by integrating numerical model with satellite data

    Directory of Open Access Journals (Sweden)

    X. Meng

    2012-10-01

    Full Text Available The impacts of inhomogeneity of the oasis interior on the oasis self-maintenance mechanism are investigated by using the mesoscale model MM5 (the fifth-generation Pennsylvania State University National Center for Atmospheric Research (NCAR mesoscale model with satellite observations of land use types, vegetation fraction and surface-layer soil moisture from MODIS (Moderate Resolution Imaging Spectroradiometer data. Four simulations were performed, among which the CTL (control simulation and MOD (moderated simulation with parameters replaced by MODIS data were used to validate the model results; EXP1 (experiment 1 and EXP2 (experiment 2 were designed to study the inhomogeneity of oasis interior. Results show that the changes of oasis heterogeneity influence the surface heat-flux partitioning, which leads to a larger "cold-wet" effect over the oasis. Vertical sections of humidity illustrate the existence of a moisture-inversion level, and the deeper moisture inversion of EXP1 and EXP2 further indicates that the relative homogeneity in the oasis interior helps produce stronger humidity inversion over the oasis, thus limiting evaporation. This is further verified by the analysis of the secondary circulation, which shows that the more homogeneous land surface conditions lead to stronger secondary circulation and less turbulent drafts over the oasis interior, playing a positive role in the oasis self-maintenance and development.

  9. Self-harm, Unintentional Injury, and Suicide in Bipolar Disorder During Maintenance Mood Stabilizer Treatment: A UK Population-Based Electronic Health Records Study.

    Science.gov (United States)

    Hayes, Joseph F; Pitman, Alexandra; Marston, Louise; Walters, Kate; Geddes, John R; King, Michael; Osborn, David P J

    2016-06-01

    Self-harm is a prominent cause of morbidity in patients with bipolar disorder and is strongly associated with suicide. There is evolving evidence that lithium use may reduce suicidal behavior, in addition to concerns that the use of anticonvulsants may increase self-harm. Information is limited about the effects of antipsychotics when used as mood stabilizer treatment. Rates of unintentional injury are poorly defined in bipolar disorder, and understanding drug associations with this outcome may shed light on mechanisms for lithium's potential antisuicidal properties through reduction in impulsive aggression. To compare rates of self-harm, unintentional injury, and suicide in patients with bipolar disorder who were prescribed lithium, valproate sodium, olanzapine, or quetiapine fumarate. This investigation was a propensity score (PS)-adjusted and PS-matched longitudinal cohort study in a nationally representative UK sample using electronic health records data collected between January 1, 1995, and December 31, 2013. Participants included all patients diagnosed as having bipolar disorder who were prescribed lithium, valproate, olanzapine, or quetiapine as maintenance mood stabilizer treatment. The primary outcome was any form of self-harm. Secondary outcomes were unintentional injury and suicide. Of the 14 396 individuals with a diagnosis of BPD, 6671 were included in the cohort, with 2148 prescribed lithium, 1670 prescribed valproate, 1477 prescribed olanzapine, and 1376 prescribed quetiapine as maintenance mood stabilizer treatment. Self-harm rates were lower in patients prescribed lithium (205; 95% CI, 175-241 per 10 000 person-years at risk [PYAR]) compared with those prescribed valproate (392; 95% CI, 334-460 per 10 000 PYAR), olanzapine (409; 95% CI, 345-483 per 10 000 PYAR), or quetiapine (582; 95% CI, 489-692 per 10 000 PYAR). This association was maintained after PS adjustment (hazard ratio [HR], 1.40; 95% CI, 1.12-1.74 for valproate, olanzapine

  10. Advanced maintenance research programs

    International Nuclear Information System (INIS)

    Marston, T.U.; Gelhaus, F.; Burke, R.

    1985-01-01

    The purpose of this paper is to provide the reader with an idea of the advanced maintenance research program at the Electric Power Research Institute (EPRI). A brief description of the maintenance-related activities is provided as a foundation for the advanced maintenance research projects. The projects can be divided into maintenance planning, preventive maintenance program development and implementation, predictive (or conditional) maintenance, and innovative maintenance techniques. The projects include hardware and software development, human factors considerations, and technology promotion and implementation. The advanced concepts include: the incorporation of artificial intelligence into outage planning; turbine and pump maintenance; rotating equipment monitoring and diagnostics with the aid of expert systems; and the development of mobile robots for nuclear power plant maintenance

  11. Building a regional health equity movement: the grantmaking model of a local health department.

    Science.gov (United States)

    Baril, Nashira; Patterson, Meghan; Boen, Courtney; Gowler, Rebekah; Norman, Nancy

    2011-01-01

    The Boston Public Health Commission's Center for Health Equity and Social Justice provides grant funding, training, and technical assistance to 15 organizations and coalitions across New England to develop, implement, and evaluate community-based policy and systems change strategies that address social determinants of health and reduce racial and ethnic health inequities. This article describes Boston Public Health Commission's health equity framework, theory of change regarding the elimination of racial and ethnic health inequities, and current grantmaking model. To conclude, the authors evaluate the grant model and offer lessons learned from providing multiyear regional grants to promote health equity.

  12. Health literacy and public health: A systematic review and integration of definitions and models

    LENUS (Irish Health Repository)

    Sorensen, Kristine

    2012-01-25

    Abstract Background Health literacy concerns the knowledge and competences of persons to meet the complex demands of health in modern society. Although its importance is increasingly recognised, there is no consensus about the definition of health literacy or about its conceptual dimensions, which limits the possibilities for measurement and comparison. The aim of the study is to review definitions and models on health literacy to develop an integrated definition and conceptual model capturing the most comprehensive evidence-based dimensions of health literacy. Methods A systematic literature review was performed to identify definitions and conceptual frameworks of health literacy. A content analysis of the definitions and conceptual frameworks was carried out to identify the central dimensions of health literacy and develop an integrated model. Results The review resulted in 17 definitions of health literacy and 12 conceptual models. Based on the content analysis, an integrative conceptual model was developed containing 12 dimensions referring to the knowledge, motivation and competencies of accessing, understanding, appraising and applying health-related information within the healthcare, disease prevention and health promotion setting, respectively. Conclusions Based upon this review, a model is proposed integrating medical and public health views of health literacy. The model can serve as a basis for developing health literacy enhancing interventions and provide a conceptual basis for the development and validation of measurement tools, capturing the different dimensions of health literacy within the healthcare, disease prevention and health promotion settings.

  13. Towards an integrative model of visual short-term memory maintenance: Evidence from the effects of attentional control, load, decay, and their interactions in childhood.

    Science.gov (United States)

    Shimi, Andria; Scerif, Gaia

    2017-12-01

    Over the past decades there has been a surge of research aiming to shed light on the nature of capacity limits to visual short-term memory (VSTM). However, an integrative account of this evidence is currently missing. We argue that investigating parameters constraining VSTM in childhood suggests a novel integrative model of VSTM maintenance, and that this in turn informs mechanisms of VSTM maintenance in adulthood. Over 3 experiments with 7-year-olds and young adults (total N=206), we provide evidence for multiple cognitive processes interacting to constrain VSTM performance. While age-related increases in storage capacity are undisputable, we replicate the finding that attentional processes control what information will be encoded and maintained in VSTM in the face of increased competition. Therefore, a central process to the current model is attentional refreshment, a mechanism that it is thought to reactivate and strengthen the signal of the visual representations. Critically, here we also show that attentional influences on VSTM are further constrained by additional factors, traditionally studied to the exclusion of each other, such as memory load and temporal decay. We propose that these processes work synergistically in an elegant manner to capture the adult-end state, whereas their less refined efficiency and modulations in childhood account for the smaller VSTM capacity that 7-year-olds demonstrate compared to older individuals. We conclude that going beyond the investigation of single cognitive mechanisms, to their interactions, holds the promise to understand both developing and fully developed maintenance in VSTM. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Health promotion in context – a reflective-analytical model

    DEFF Research Database (Denmark)

    Liveng, Anne; Andersen, Heidi Lene; Lehn-Christiansen, Sine

    2018-01-01

    model,” which is presented in this article. The model provides a framework for the analysis of health-promotion initiatives, employing eight perspectives each intertwined with the others. It is based on the assumption that health and health inequities are contextual and that the theoretically inspired...

  15. A sequential model for the structure of health care utilization.

    NARCIS (Netherlands)

    Herrmann, W.J.; Haarmann, A.; Baerheim, A.

    2017-01-01

    Traditional measurement models of health care utilization are not able to represent the complex structure of health care utilization. In this qualitative study, we, therefore, developed a new model to represent the health care utilization structure. In Norway and Germany, we conducted episodic

  16. Does the Model Matter? Comparing Video Self-Modeling and Video Adult Modeling for Task Acquisition and Maintenance by Adolescents with Autism Spectrum Disorders

    Science.gov (United States)

    Cihak, David F.; Schrader, Linda

    2009-01-01

    The purpose of this study was to compare the effectiveness and efficiency of learning and maintaining vocational chain tasks using video self-modeling and video adult modeling instruction. Four adolescents with autism spectrum disorders were taught vocational and prevocational skills. Although both video modeling conditions were effective for…

  17. VEHICLE REPAIR AND MAINTENANCE COSTS IN NIGERIA ...

    African Journals Online (AJOL)

    A standard model was established for the prediction of repair and maintenance costs of vehicles in a non-profit making government parastatal. The model was derived based on data collected over a ten year period from a non-profit making government parastatal, and it predicts repair and maintenance costs as a linear ...

  18. Scientific Opinion on the substantiation of health claims related to glycaemic carbohydrates and maintenance of normal brain function pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    2015-01-01

    Following applications from Dextro Energy GmbH & Co. KG, submitted for the authorisation of health claims pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Germany, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver...... an opinion on the scientific substantiation of health claims related to glycaemic carbohydrates and maintenance of normal brain function. The scope of the applications was proposed to fall under health claims based on newly developed scientific evidence. The Panel considers that the food constituent...

  19. Health Insurance: principles, models and the Nigerian National ...

    African Journals Online (AJOL)

    ... more resources to the health care sector and improve the level of access and ... This article amongst other things outlines the principles and models of health ... journal articles, abstracts, relevant books and internet articles were reviewed.

  20. A MODEL FOR HIGHER EDUCATION CAMPUS HEALTH SERVICES

    African Journals Online (AJOL)

    2010-03-17

    Mar 17, 2010 ... generation was used to develop a holistic healthcare model for a higher education campus' health service. It became ... innovative. Health plays a .... conducted will set the tone for the interactive process of holistic healthcare.