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Sample records for controlled interrupted time

  1. Interrupted Time Series Versus Statistical Process Control in Quality Improvement Projects.

    Science.gov (United States)

    Andersson Hagiwara, Magnus; Andersson Gäre, Boel; Elg, Mattias

    2016-01-01

    To measure the effect of quality improvement interventions, it is appropriate to use analysis methods that measure data over time. Examples of such methods include statistical process control analysis and interrupted time series with segmented regression analysis. This article compares the use of statistical process control analysis and interrupted time series with segmented regression analysis for evaluating the longitudinal effects of quality improvement interventions, using an example study on an evaluation of a computerized decision support system.

  2. A combined teamwork training and work standardisation intervention in operating theatres: controlled interrupted time series study.

    Science.gov (United States)

    Morgan, Lauren; Pickering, Sharon P; Hadi, Mohammed; Robertson, Eleanor; New, Steve; Griffin, Damian; Collins, Gary; Rivero-Arias, Oliver; Catchpole, Ken; McCulloch, Peter

    2015-02-01

    Teamwork training and system standardisation have both been proposed to reduce error and harm in surgery. Since the approaches differ markedly, there is potential for synergy between them. Controlled interrupted time series with a 3 month intervention and observation phases before and after. Operating theatres conducting elective orthopaedic surgery in a single hospital system (UK Hospital Trust). Teamwork training based on crew resource management plus training and follow-up support in developing standardised operating procedures. Focus of subsequent standardisation efforts decided by theatre staff. Paired observers watched whole procedures together. We assessed non-technical skills using NOTECHS II, technical performance using glitch rate and compliance with WHO checklist using a simple quality tool. We measured complication and readmission rates and hospital stay using hospital administrative records. Before/after change was compared in the active and control groups using two-way ANOVA and regression models. 1121 patients were operated on before and 1100 after intervention. 44 operations were observed before and 50 afterwards. Non-technical skills (p=0.002) and WHO compliance (pteamwork and system improvement causes marked improvements in team behaviour and WHO performance, but not technical performance or outcome. These findings are consistent with the synergistic hypothesis, but larger controlled studies with a strong implementation strategy are required to test potential outcome effects. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Mental health impacts of flooding: a controlled interrupted time series analysis of prescribing data in England.

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    Milojevic, Ai; Armstrong, Ben; Wilkinson, Paul

    2017-10-01

    There is emerging evidence that people affected by flooding suffer adverse impacts on their mental well-being, mostly based on self-reports. We examined prescription records for drugs used in the management of common mental disorder among primary care practices located in the vicinity of recent large flood events in England, 2011-2014. A controlled interrupted time series analysis was conducted of the number of prescribing items for antidepressant drugs in the year before and after the flood onset. Pre-post changes were compared by distance of the practice from the inundated boundaries among 930 practices located within 10 km of a flood. After control for deprivation and population density, there was an increase of 0.59% (95% CI 0.24 to 0.94) prescriptions in the postflood year among practices located within 1 km of a flood over and above the change observed in the furthest distance band. The increase was greater in more deprived areas. This study suggests an increase in prescribed antidepressant drugs in the year after flooding in primary care practices close to recent major floods in England. The degree to which the increase is actually concentrated in those flooded can only be determined by more detailed linkage studies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. An electronic trigger tool to optimise intravenous to oral antibiotic switch: a controlled, interrupted time series study

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    Marvin A. H. Berrevoets

    2017-08-01

    Full Text Available Abstract Background Timely switch from intravenous (iv antibiotics to oral therapy is a key component of antimicrobial stewardship programs in order to improve patient safety, promote early discharge and reduce costs. We have introduced a time-efficient and easily implementable intervention that relies on a computerized trigger tool, which identifies patients who are candidates for an iv to oral antibiotic switch. Methods The intervention was introduced on all internal medicine wards in a teaching hospital. Patients were automatically identified by an electronic trigger tool when parenteral antibiotics were used for >48 h and clinical or pharmacological data did not preclude switch therapy. A weekly educational session was introduced to alert the physicians on the intervention wards. The intervention wards were compared with control wards, which included all other hospital wards. An interrupted time-series analysis was performed to compare the pre-intervention period with the post-intervention period using ‘% of i.v. prescriptions >72 h’ and ‘median duration of iv therapy per prescription’ as outcomes. We performed a detailed prospective evaluation on a subset of 244 prescriptions to evaluate the efficacy and appropriateness of the intervention. Results The number of intravenous prescriptions longer than 72 h was reduced by 19% in the intervention group (n = 1519 (p < 0.01 and the median duration of iv antibiotics was reduced with 0.8 days (p = <0.05. Compared to the control group (n = 4366 the intervention was responsible for an additional decrease of 13% (p < 0.05 in prolonged prescriptions. The detailed prospective evaluation of a subgroup of patients showed that adherence to the electronic reminder was 72%. Conclusions An electronic trigger tool combined with a weekly educational session was effective in reducing the duration of intravenous antimicrobial therapy.

  5. Thinking aloud in the presence of interruptions and time constraints

    DEFF Research Database (Denmark)

    Hertzum, Morten; Holmegaard, Kristin Due

    2013-01-01

    and time constraints, two frequent elements of real-world activities. We find that the presence of auditory, visual, audiovisual, or no interruptions interacts with thinking aloud for task solution rate, task completion time, and participants’ fixation rate. Thinking-aloud participants also spend longer......Thinking aloud is widely used for usability evaluation and its reactivity is therefore important to the quality of evaluation results. This study investigates whether thinking aloud (i.e., verbalization at levels 1 and 2) affects the behaviour of users who perform tasks that involve interruptions...... responding to interruptions than control participants. Conversely, the absence or presence of time constraints does not interact with thinking aloud, suggesting that time pressure is less likely to make thinking aloud reactive than previously assumed. Our results inform practitioners faced with the decision...

  6. Enhanced Interrupt Response Time in the nMPRA based on Embedded Real Time Microcontrollers

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    GAITAN, N. C.

    2017-08-01

    Full Text Available In any real-time operating system, task switching and scheduling, interrupts, synchronization and communication between processes, represent major problems. The implementation of these mechanisms through software generates significant delays for many applications. The nMPRA (Multi Pipeline Register Architecture architecture is designed for the implementation of real-time embedded microcontrollers. It supports the competitive execution of n tasks, enabling very fast switching between them, with a usual delay of one machine cycle and a maximum of 3 machine cycles, for the memory-related work instructions. This is because each task has its own PC (Program Counter, set of pipeline registers and a general registers file. The nMPRA is provided with an advanced distributed interrupt controller that implements the concept of "interrupts as threads". This allows the attachment of one or more interrupts to the same task. In this context, the original contribution of this article is to presents the solutions for improving the response time to interrupts when a task has attached a large number of interrupts. The proposed solutions enhance the original architecture for interrupts logic in order to transfer control, to the interrupt handler as soon as possible, and to create an interrupt prioritization at task level.

  7. Muscle-invasive bladder cancer treated with external beam radiation: influence of total dose, overall treatment time, and treatment interruption on local control

    International Nuclear Information System (INIS)

    Moonen, L.; Voet, H. van der; Nijs, R. de; Horenblas, S.; Hart, A.A.M.; Bartelink, H.

    1998-01-01

    Purpose: To evaluate and eventually quantify a possible influence of tumor proliferation during the external radiation course on local control in muscle invasive bladder cancer. Methods and Materials: The influence of total dose, overall treatment time, and treatment interruption has retrospectively been analyzed in a series of 379 patients with nonmetastasized, muscle-invasive transitional cell carcinoma of the urinary bladder. All patients received external beam radiotherapy at the Netherlands Cancer Institute between 1977 and 1990. Total dose varied between 50 and 75 Gy with a mean of 60.5 Gy and a median of 60.4 Gy. Overall treatment time varied between 20 and 270 days with a mean of 49 days and a median of 41 days. Number of fractions varied between 17 and 36 with a mean of 27 and a median of 26. Two hundred and forty-four patients had a continuous radiation course, whereas 135 had an intended split course or an unintended treatment interruption. Median follow-up was 22 months for all patients and 82 months for the 30 patients still alive at last follow-up. A stepwise procedure using proportional hazard regression has been used to identify prognostic treatment factors with respect to local recurrence as sole first recurrence. Results: One hundred and thirty-six patients experienced a local recurrence and 120 of these occurred before regional or distant metastases. The actuarial local control rate was 40.3% at 5 years and 32.3% at 10 years. In a multivariate analysis total dose showed a significant association with local control (p 0.0039), however in a markedly nonlinear way. In fact only those patients treated with a dose below 57.5 Gy had a significant higher bladder relapse rate, whereas no difference in relapse rate was found among patients treated with doses above 57.5 Gy. This remained the case even after adjustment for overall treatment time and all significant tumor and patient characteristics. The Normalized Tumor Dose (NTD) (α/β = 10) and NTD (

  8. Implementation and impact of an audit and feedback antimicrobial stewardship intervention in the orthopaedics department of a tertiary-care hospital: a controlled interrupted time series study.

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    Tavares, Margarida; Carvalho, Ana Cláudia; Almeida, José Pedro; Andrade, Paulo; São-Simão, Ricardo; Soares, Pedro; Alves, Carlos; Pinto, Rui; Fontanet, Arnaud; Watier, Laurence

    2018-06-01

    A prospective audit and feedback antimicrobial stewardship intervention conducted in the Orthopaedics Department of a university hospital in Portugal was evaluated by comparing an interrupted time series in the intervention group with a non-intervention (control) group. Monthly antibiotic use (except cefazolin) was measured as the World Health Organization's Anatomical Therapeutic Chemical defined daily doses (ATC-DDD) from January 2012 to September 2016, excluding the 6-month phase of intervention implementation starting on 1 January 2015. Compared with the control group, the intervention group had a monthly decrease in the use of fluoroquinolones by 2.3 DDD/1000 patient-days [95% confidence interval (CI) -3.97 to -0.63]. An increase in the use of penicillins by 103.3 DDD/1000 patient-days (95% CI 47.42 to 159.10) was associated with intervention implementation, followed by a decrease during the intervention period (slope = -5.2, 95% CI -8.56 to -1.82). In the challenging scenario of treatment of osteoarticular and prosthetic joint infections, an audit and feedback intervention reduced antibiotic exposure and spectrum. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  9. The effect of health insurance and health facility-upgrades on hospital deliveries in rural Nigeria: a controlled interrupted time-series study.

    Science.gov (United States)

    Brals, Daniëlla; Aderibigbe, Sunday A; Wit, Ferdinand W; van Ophem, Johannes C M; van der List, Marijn; Osagbemi, Gordon K; Hendriks, Marleen E; Akande, Tanimola M; Boele van Hensbroek, Michael; Schultsz, Constance

    2017-09-01

    Access to quality obstetric care is considered essential to reducing maternal and new-born mortality. We evaluated the effect of the introduction of a multifaceted voluntary health insurance programme on hospital deliveries in rural Nigeria. We used an interrupted time-series design, including a control group. The intervention consisted of providing voluntary health insurance covering primary and secondary healthcare, including antenatal and obstetric care, combined with improving the quality of healthcare facilities. We compared changes in hospital deliveries from 1 May 2005 to 30 April 2013 between the programme area and control area in a difference-in-differences analysis with multiple time periods, adjusting for observed confounders. Data were collected through household surveys. Eligible households ( n = 1500) were selected from a stratified probability sample of enumeration areas. All deliveries during the 4-year baseline period ( n = 460) and 4-year follow-up period ( n = 380) were included. Insurance coverage increased from 0% before the insurance was introduced to 70.2% in April 2013 in the programme area. In the control area insurance coverage remained 0% between May 2005 and April 2013. Although hospital deliveries followed a common stable trend over the 4 pre-programme years ( P = 0.89), the increase in hospital deliveries during the 4-year follow-up period in the programme area was 29.3 percentage points (95% CI: 16.1 to 42.6; P health insurance but who could make use of the upgraded care delivered significantly more often in a hospital during the follow-up period than women living in the control area ( P = 0.04). Voluntary health insurance combined with quality healthcare services is highly effective in increasing hospital deliveries in rural Nigeria, by improving access to healthcare for insured and uninsured women in the programme area. © The Author 2017. Published by Oxford University Press in association with The London School of Hygiene and

  10. Immediate and sustained effects of user fee exemption on healthcare utilization among children under five in Burkina Faso: A controlled interrupted time-series analysis.

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    Zombré, David; De Allegri, Manuela; Ridde, Valéry

    2017-04-01

    Little is known about the long-term effects of user fee exemption policies on health care use in developing countries. We examined the association between user fee exemption and health care use among children under five in Burkina Faso. We also examined how factors related to characteristics of health facilities and their environment moderate this association. We used a multilevel controlled interrupted time-series design to examine the strength of effect and long term effects of user fee exemption policy on the rate of health service utilization in children under five between January 2004 and December 2014. The initiation of the intervention more than doubled the utilization rate with an immediate 132.596% increase in intervention facilities (IRR: 2.326; 95% CI: 1.980 to 2.672). The effect of the intervention was 32.766% higher in facilities with higher workforce density (IRR: 1.328; 95% CI (1.209-1.446)) and during the rainy season (IRR:1.2001; 95% CI: 1.0953-1.3149), but not significant in facilities with higher dispersed populations (IRR: 1.075; 95% CI: (0.942-1.207)). Although the intervention effect was substantially significant immediately following its inception, the pace of growth, while positive over a first phase, decelerated to stabilize itself three years and 7 months later before starting to decrease slowly towards the end of the study period. This study provides additional evidence to support user fee exemption policies complemented by improvements in health care quality. Future work should include an assessment of the impact of user fee exemption on infant morbidity and mortality and better discuss factors that could explain the slowdown in this upward trend of utilization rates three and a half years after the intervention onset. Copyright © 2017. Published by Elsevier Ltd.

  11. The effect of interruptions and prolonged treatment time in radiotherapy for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Kwong, Dora L.W.; Sham, Jonathan S.T.; Chua, Daniel T.T.; Choy, Damon T.K.; Au, Gordon K.H.; Wu, P.M.

    1997-01-01

    Purpose: The effect of interruptions and prolonged overall treatment time in radiotherapy for nasopharyngeal carcinoma and the significance of timing of interruption was investigated. Methods and Materials: Treatment records of 229 patients treated with continuous course (CC) and 567 patients treated with split course (SC) radiotherapy for nonmetastatic NPC were reviewed. Overall treatment time without inclusion of time for boost was calculated. Treatment that extended 1 week beyond scheduled time was considered prolonged. Outcome in patients who completed treatment 'per schedule' were compared with those who had 'prolonged' treatment. Because of known patient selection bias between CC and SC, patients on the two schedules were analyzed separately. Multivariate analysis was performed for patients on SC. Total number of days of interruption, age, sex, T and N stage, and the use of boost were tested for the whole SC group. Analysis on the effect of timing of interruption was performed in a subgroup of 223 patients on SC who had a single unplanned interruption. Timing of interruption, either before or after the fourth week for the unplanned interruption, was tested in addition to the other variables in multivariate analysis for this subgroup of SC. Results: Twenty-seven (11.8%) patients on CC and 96 (16.9%) patients on SC had prolonged treatment. Patients on SC who had prolonged treatment had significantly poorer loco-regional control rate and disease free survival when compared with those who completed radiotherapy per schedule (p = 0.0063 and 0.001, respectively, with adjustment for stage). For CC, the effect of prolonged treatment on outcome was not significant. The small number of events for patients on CC probably account for the insignificant finding. The number of days of interruption was confirmed as prognostic factor, independent of T and N stages, for loco-regional control and disease-free survival in multivariate analysis for SC. The hazard rate for loco

  12. Optimal treatment interruptions control of TB transmission model

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    Nainggolan, Jonner; Suparwati, Titik; Kawuwung, Westy B.

    2018-03-01

    A tuberculosis model which incorporates treatment interruptions of infectives is established. Optimal control of individuals infected with active TB is given in the model. It is obtained that the control reproduction numbers is smaller than the reproduction number, this means treatment controls could optimize the decrease in the spread of active TB. For this model, controls on treatment of infection individuals to reduce the actively infected individual populations, by application the Pontryagins Maximum Principle for optimal control. The result further emphasized the importance of controlling disease relapse in reducing the number of actively infected and treatment interruptions individuals with tuberculosis.

  13. Acute glucoregulatory and vascular outcomes of three strategies for interrupting prolonged sitting time in postmenopausal women: A pilot, laboratory-based, randomized, controlled, 4-condition, 4-period crossover trial.

    Directory of Open Access Journals (Sweden)

    Jacqueline Kerr

    Full Text Available Prolonged sitting is associated with cardiometabolic and vascular disease. Despite emerging evidence regarding the acute health benefits of interrupting prolonged sitting time, the effectiveness of different modalities in older adults (who sit the most is unclear.In preparation for a future randomized controlled trial, we enrolled 10 sedentary, overweight or obese, postmenopausal women (mean age 66 years ±9; mean body mass index 30.6 kg/m2 ±4.2 in a 4-condition, 4-period crossover feasibility pilot study in San Diego to test 3 different sitting interruption modalities designed to improve glucoregulatory and vascular outcomes compared to a prolonged sitting control condition. The interruption modalities included: a 2 minutes standing every 20 minutes; b 2 minutes walking every hour; and c 10 minutes standing every hour. During each 5-hr condition, participants consumed two identical, standardized meals. Blood samples, blood pressure, and heart rate were collected every 30 minutes. Endothelial function of the superficial femoral artery was measured at baseline and end of each 5-hr condition using flow-mediated dilation (FMD. Participants completed each condition on separate days, in randomized order. This feasibility pilot study was not powered to detect statistically significant differences in the various outcomes, however, analytic methods (mixed models were used to test statistical significance within the small sample size.Nine participants completed all 4 study visits, one participant completed 3 study visits and then was lost to follow up. Net incremental area under the curve (iAUC values for postprandial plasma glucose and insulin during the 5-hr sitting interruption conditions were not significantly different compared to the control condition. Exploratory analyses revealed that the 2-minute standing every 20 minutes and the 2-minute walking every hour conditions were associated with a significantly lower glycemic response to the second

  14. The time-course of recovery from interruption during reading: eye movement evidence for the role of interruption lag and spatial memory.

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    Cane, James E; Cauchard, Fabrice; Weger, Ulrich W

    2012-01-01

    Two experiments examined how interruptions impact reading and how interruption lags and the reader's spatial memory affect the recovery from such interruptions. Participants read paragraphs of text and were interrupted unpredictably by a spoken news story while their eye movements were monitored. Time made available for consolidation prior to responding to the interruption did not aid reading resumption. However, providing readers with a visual cue that indicated the interruption location did aid task resumption substantially in Experiment 2. Taken together, the findings show that the recovery from interruptions during reading draws on spatial memory resources and can be aided by processes that support spatial memory. Practical implications are discussed.

  15. Impact of Frequent Interruption on Nurses' Patient-Controlled Analgesia Programming Performance.

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    Campoe, Kristi R; Giuliano, Karen K

    2017-12-01

    The purpose was to add to the body of knowledge regarding the impact of interruption on acute care nurses' cognitive workload, total task completion times, nurse frustration, and medication administration error while programming a patient-controlled analgesia (PCA) pump. Data support that the severity of medication administration error increases with the number of interruptions, which is especially critical during the administration of high-risk medications. Bar code technology, interruption-free zones, and medication safety vests have been shown to decrease administration-related errors. However, there are few published data regarding the impact of number of interruptions on nurses' clinical performance during PCA programming. Nine acute care nurses completed three PCA pump programming tasks in a simulation laboratory. Programming tasks were completed under three conditions where the number of interruptions varied between two, four, and six. Outcome measures included cognitive workload (six NASA Task Load Index [NASA-TLX] subscales), total task completion time (seconds), nurse frustration (NASA-TLX Subscale 6), and PCA medication administration error (incorrect final programming). Increases in the number of interruptions were associated with significant increases in total task completion time ( p = .003). We also found increases in nurses' cognitive workload, nurse frustration, and PCA pump programming errors, but these increases were not statistically significant. Complex technology use permeates the acute care nursing practice environment. These results add new knowledge on nurses' clinical performance during PCA pump programming and high-risk medication administration.

  16. Control instrumentation and data handling of heavy current inductive load interrupter

    International Nuclear Information System (INIS)

    Calpin, J.E.

    1983-01-01

    The heavy duty DC interrupter is a switching system with the ability to interrupt very high inductive currents with precise timing, work in concert with an additional number of similar systems, and withstand fast recovery voltages (30 kV) after interruption. Further, it is required to be self-protecting and the high current busses isolated to 50 kV DC and subjected to 95 kV BIL test voltages. Interruption is accomplished by the separation of vacuum interrupter contacts, which prior to counterpulse arc for milliseconds, generating horrendous noise signals of frequencies from DC to ultraviolet. Neutralization of such signals on the computer interface was effected by unique BALUN filters on 25 control and status lines. The noise abatement circuitry rationale will be discussed along with triple shielding, Hall effect current level sensing and light pipe communication between high level busses and interface HTL cards. Triggering of the isolated counterpulse circuitry will be outlined. The self-protective aspects of the system employ current sensors to reclose the interrupter if current persists for two milliseconds after counterpulse

  17. Interrupted time-series analysis: studying trends in neurosurgery.

    Science.gov (United States)

    Wong, Ricky H; Smieliauskas, Fabrice; Pan, I-Wen; Lam, Sandi K

    2015-12-01

    OBJECT Neurosurgery studies traditionally have evaluated the effects of interventions on health care outcomes by studying overall changes in measured outcomes over time. Yet, this type of linear analysis is limited due to lack of consideration of the trend's effects both pre- and postintervention and the potential for confounding influences. The aim of this study was to illustrate interrupted time-series analysis (ITSA) as applied to an example in the neurosurgical literature and highlight ITSA's potential for future applications. METHODS The methods used in previous neurosurgical studies were analyzed and then compared with the methodology of ITSA. RESULTS The ITSA method was identified in the neurosurgical literature as an important technique for isolating the effect of an intervention (such as a policy change or a quality and safety initiative) on a health outcome independent of other factors driving trends in the outcome. The authors determined that ITSA allows for analysis of the intervention's immediate impact on outcome level and on subsequent trends and enables a more careful measure of the causal effects of interventions on health care outcomes. CONCLUSIONS ITSA represents a significant improvement over traditional observational study designs in quantifying the impact of an intervention. ITSA is a useful statistical procedure to understand, consider, and implement as the field of neurosurgery evolves in sophistication in big-data analytics, economics, and health services research.

  18. Interrupt Handlers in Java

    DEFF Research Database (Denmark)

    Korsholm, Stephan; Schoeberl, Martin; Ravn, Anders Peter

    2008-01-01

    An important part of implementing device drivers is to control the interrupt facilities of the hardware platform and to program interrupt handlers. Current methods for handling interrupts in Java use a server thread waiting for the VM to signal an interrupt occurrence. It means that the interrupt...... is handled at a later time, which has some disadvantages. We present constructs that allow interrupts to be handled directly and not at a later point decided by a scheduler. A desirable feature of our approach is that we do not require a native middleware layer but can handle interrupts entirely with Java...... code. We have implemented our approach using an interpreter and a Java processor, and give an example demonstrating its use....

  19. Statistical method for the control of the electric power service interruptions (second part); Metodo de control estadistico de las interrupciones del servicio electrico (2a. parte)

    Energy Technology Data Exchange (ETDEWEB)

    Issouribehere, Pedro E.; Barbero, Juan C. [Universidad Nacional de La Plata (UNLP), Buenos Aires (Argentina). Facultad de Ingenieria. Inst. de Investigaciones Tecnologicas para Redes y Equipos Electricos (IITREE-LAT)]. E-mail: iitree@.ing.unlp.edu.ar; Martinez, Jorge L.; Galinski, Alejandro [Ente Nacional Regulador de la Electricidad (ENRE), Buenos Aires (Argentina)

    2001-07-01

    This paper presents the register of interruptions in application points of the concession areas of three concessionaires. The reliability indexes are presented of the controlled sites: interruption ratio {lambda}, time of average reposition r and unavailability Q obtained with the field information recompiled during three years from June 2000. The paper also obtains by concessionaire, the ratios of brief interruptions occurrence which constitutes another indicator of the Electric Service Quality.

  20. Long-term effects of flooding on mortality in England and Wales, 1994-2005: controlled interrupted time-series analysis

    Directory of Open Access Journals (Sweden)

    Leonardi Giovanni

    2011-02-01

    Full Text Available Abstract Background Limited evidence suggests that being flooded may increase mortality and morbidity among affected householders not just at the time of the flood but for months afterwards. The objective of this study is to explore the methods for quantifying such long-term health effects of flooding by analysis of routine mortality registrations in England and Wales. Methods Mortality data, geo-referenced by postcode of residence, were linked to a national database of flood events for 1994 to 2005. The ratio of mortality in the post-flood year to that in the pre-flood year within flooded postcodes was compared with that in non-flooded boundary areas (within 5 km of a flood. Further analyses compared the observed number of flood-area deaths in the year after flooding with the number expected from analysis of mortality trends stratified by region, age-group, sex, deprivation group and urban-rural status. Results Among the 319 recorded floods, there were 771 deaths in the year before flooding and 693 deaths in the year after (post-/pre-flood ratio of 0.90, 95% CI 0.82, 1.00. This ratio did not vary substantially by age, sex, population density or deprivation. A similar post-flood 'deficit' of deaths was suggested by the analyses based on observed/expected deaths. Conclusions The observed post-flood 'deficit' of deaths is counter-intuitive and difficult to interpret because of the possible influence of population displacement caused by flooding. The bias that might arise from such displacement remains unquantified but has important implications for future studies that use place of residence as a marker of exposure.

  1. Long-term effects of flooding on mortality in England and Wales, 1994-2005: controlled interrupted time-series analysis

    Science.gov (United States)

    2011-01-01

    Background Limited evidence suggests that being flooded may increase mortality and morbidity among affected householders not just at the time of the flood but for months afterwards. The objective of this study is to explore the methods for quantifying such long-term health effects of flooding by analysis of routine mortality registrations in England and Wales. Methods Mortality data, geo-referenced by postcode of residence, were linked to a national database of flood events for 1994 to 2005. The ratio of mortality in the post-flood year to that in the pre-flood year within flooded postcodes was compared with that in non-flooded boundary areas (within 5 km of a flood). Further analyses compared the observed number of flood-area deaths in the year after flooding with the number expected from analysis of mortality trends stratified by region, age-group, sex, deprivation group and urban-rural status. Results Among the 319 recorded floods, there were 771 deaths in the year before flooding and 693 deaths in the year after (post-/pre-flood ratio of 0.90, 95% CI 0.82, 1.00). This ratio did not vary substantially by age, sex, population density or deprivation. A similar post-flood 'deficit' of deaths was suggested by the analyses based on observed/expected deaths. Conclusions The observed post-flood 'deficit' of deaths is counter-intuitive and difficult to interpret because of the possible influence of population displacement caused by flooding. The bias that might arise from such displacement remains unquantified but has important implications for future studies that use place of residence as a marker of exposure. PMID:21288358

  2. Real time interrupt handling using FORTRAN IV plus under RSX-11M

    International Nuclear Information System (INIS)

    Schultz, D.E.

    1981-01-01

    A real-time data acquisition application for a linear accelerator is described. The important programming features of this application are use of connect to interrupt, a shared library, map to I/O page, and a shared data area. How you can provide rapid interrupt handling using these tools from FORTRAN IV PLUS is explained

  3. Hospital admission interviews are time-consuming with several interruptions

    DEFF Research Database (Denmark)

    Ghazanfar, Misbah N; Honoré, Per Gustaf Hartvig; Nielsen, Trine R H

    2012-01-01

    The admission interview is an important procedure to reduce medication errors. Studies indicate that physicians do not spend much time on the interview and that the major obstacles are lack of time and heavy workload. The aim of this study was to measure the time physicians spend on admission...... interviews and to describe factors that affect time consumption....

  4. Interrupted time series analysis in drug utilization research is increasing: systematic review and recommendations.

    Science.gov (United States)

    Jandoc, Racquel; Burden, Andrea M; Mamdani, Muhammad; Lévesque, Linda E; Cadarette, Suzanne M

    2015-08-01

    To describe the use and reporting of interrupted time series methods in drug utilization research. We completed a systematic search of MEDLINE, Web of Science, and reference lists to identify English language articles through to December 2013 that used interrupted time series methods in drug utilization research. We tabulated the number of studies by publication year and summarized methodological detail. We identified 220 eligible empirical applications since 1984. Only 17 (8%) were published before 2000, and 90 (41%) were published since 2010. Segmented regression was the most commonly applied interrupted time series method (67%). Most studies assessed drug policy changes (51%, n = 112); 22% (n = 48) examined the impact of new evidence, 18% (n = 39) examined safety advisories, and 16% (n = 35) examined quality improvement interventions. Autocorrelation was considered in 66% of studies, 31% reported adjusting for seasonality, and 15% accounted for nonstationarity. Use of interrupted time series methods in drug utilization research has increased, particularly in recent years. Despite methodological recommendations, there is large variation in reporting of analytic methods. Developing methodological and reporting standards for interrupted time series analysis is important to improve its application in drug utilization research, and we provide recommendations for consideration. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Power Supply Interruption Costs: Models and Methods Incorporating Time Dependent Patterns

    International Nuclear Information System (INIS)

    Kjoelle, G.H.

    1996-12-01

    This doctoral thesis develops models and methods for estimation of annual interruption costs for delivery points, emphasizing the handling of time dependent patterns and uncertainties in the variables determining the annual costs. It presents an analytical method for calculation of annual expected interruption costs for delivery points in radial systems, based on a radial reliability model, with time dependent variables. And a similar method for meshed systems, based on a list of outage events, assuming that these events are found in advance from load flow and contingency analyses. A Monte Carlo simulation model is given which handles both time variations and stochastic variations in the input variables and is based on the same list of outage events. This general procedure for radial and meshed systems provides expectation values and probability distributions for interruption costs from delivery points. There is also a procedure for handling uncertainties in input variables by a fuzzy description, giving annual interruption costs as a fuzzy membership function. The methods are developed for practical applications in radial and meshed systems, based on available data from failure statistics, load registrations and customer surveys. Traditional reliability indices such as annual interruption time, power- and energy not supplied, are calculated as by-products. The methods are presented as algorithms and/or procedures which are available as prototypes. 97 refs., 114 figs., 62 tabs

  6. Power Supply Interruption Costs: Models and Methods Incorporating Time Dependent Patterns

    Energy Technology Data Exchange (ETDEWEB)

    Kjoelle, G.H.

    1996-12-01

    This doctoral thesis develops models and methods for estimation of annual interruption costs for delivery points, emphasizing the handling of time dependent patterns and uncertainties in the variables determining the annual costs. It presents an analytical method for calculation of annual expected interruption costs for delivery points in radial systems, based on a radial reliability model, with time dependent variables. And a similar method for meshed systems, based on a list of outage events, assuming that these events are found in advance from load flow and contingency analyses. A Monte Carlo simulation model is given which handles both time variations and stochastic variations in the input variables and is based on the same list of outage events. This general procedure for radial and meshed systems provides expectation values and probability distributions for interruption costs from delivery points. There is also a procedure for handling uncertainties in input variables by a fuzzy description, giving annual interruption costs as a fuzzy membership function. The methods are developed for practical applications in radial and meshed systems, based on available data from failure statistics, load registrations and customer surveys. Traditional reliability indices such as annual interruption time, power- and energy not supplied, are calculated as by-products. The methods are presented as algorithms and/or procedures which are available as prototypes. 97 refs., 114 figs., 62 tabs.

  7. A randomized controlled trial of daily sedation interruption in critically ill children

    NARCIS (Netherlands)

    Vet, N.J.; Wildt, S.N. de; Verlaat, C.W.; Knibbe, C.A.; Mooij, M.G.; Woensel, J.B. van; Rosmalen, J. van; Tibboel, D.; Hoog, M. de

    2016-01-01

    PURPOSE: To compare daily sedation interruption plus protocolized sedation (DSI + PS) to protocolized sedation only (PS) in critically ill children. METHODS: In this multicenter randomized controlled trial in three pediatric intensive care units in the Netherlands, mechanically ventilated critically

  8. A randomized controlled trial of daily sedation interruption in critically ill children

    NARCIS (Netherlands)

    Vet, Nienke J.; de Wildt, Saskia N.; Verlaat, Carin W. M.; Knibbe, Catherijne A. J.; Mooij, Miriam G.; van Woensel, Job B. M.; van Rosmalen, Joost; Tibboel, Dick; de Hoog, Matthijs

    2016-01-01

    To compare daily sedation interruption plus protocolized sedation (DSI + PS) to protocolized sedation only (PS) in critically ill children. In this multicenter randomized controlled trial in three pediatric intensive care units in the Netherlands, mechanically ventilated critically ill children with

  9. The Impact of the Hotel Room Tax: An Interrupted Time Series Approach

    OpenAIRE

    Bonham, Carl; Fujii, Edwin; Im, Eric; Mak, James

    1992-01-01

    Employs interrupted time series analysis to estimate ex post the impact of a hotel room tax on real net hotel revenues by analyzing that time series before and after the imposition of the tax. Finds that the tax had a negligible effect on real hotel revenues.

  10. Reduction of Hospital Physicians' Workflow Interruptions: A Controlled Unit-Based Intervention Study

    Directory of Open Access Journals (Sweden)

    Matthias Weigl

    2012-01-01

    Full Text Available Highly interruptive clinical environments may cause work stress and suboptimal clinical care. This study features an intervention to reduce workflow interruptions by re-designing work and organizational practices in hospital physicians providing ward coverage. A prospective, controlled intervention was conducted in two surgical and two internal wards. The intervention was based on physician quality circles - a participative technique to involve employees in the development of solutions to overcome work-related stressors. Outcome measures were the frequency of observed workflow interruptions. Workflow interruptions by fellow physicians and nursing staff were significantly lower after the intervention. However, a similar decrease was also observed in control units. Additional interviews to explore process-related factors suggested that there might have been spill-over effects in the sense that solutions were not strictly confined to the intervention group. Recommendations for further research on the effectiveness and consequences of such interventions for professional communication and patient safety are discussed.

  11. A Unified Framework for Estimating Minimum Detectable Effects for Comparative Short Interrupted Time Series Designs

    Science.gov (United States)

    Price, Cristofer; Unlu, Fatih

    2014-01-01

    The Comparative Short Interrupted Time Series (C-SITS) design is a frequently employed quasi-experimental method, in which the pre- and post-intervention changes observed in the outcome levels of a treatment group is compared with those of a comparison group where the difference between the former and the latter is attributed to the treatment. The…

  12. Comparison Groups in Short Interrupted Time-Series: An Illustration Evaluating No Child Left Behind

    Science.gov (United States)

    Wong, Manyee; Cook, Thomas D.; Steiner, Peter M.

    2009-01-01

    Interrupted time-series (ITS) are often used to assess the causal effect of a planned or even unplanned shock introduced into an on-going process. The pre-intervention slope is supposed to index the causal counterfactual, and deviations from it in mean, slope or variance are used to indicate an effect. However, a secure causal inference is only…

  13. PERFORMANCE COMPARISON OF USART COMMUNICATION BETWEEN REAL TIME OPERATING SYSTEM (RTOS AND NATIVE INTERRUPT

    Directory of Open Access Journals (Sweden)

    Novian Habibie

    2016-02-01

    Full Text Available Comunication between microcontrollers is one of the crucial point in embedded sytems. On the other hand, embedded system must be able to run many parallel task simultaneously. To handle this, we need a reliabe system that can do a multitasking without decreasing every task’s performance. The most widely used methods for multitasking in embedded systems are using Interrupt Service Routine (ISR or using Real Time Operating System (RTOS. This research compared perfomance of USART communication on system with RTOS to a system that use interrupt. Experiments run on two identical development board XMega A3BU-Xplained which used intenal sensor (light and temperature and used servo as external component. Perfomance comparison done by counting ping time (elapsing time to transmit data and get a reply as a mark that data has been received and compare it. This experiments divided into two scenarios: (1 system loaded with many tasks, (2 system loaded with few tasks. Result of the experiments show that communication will be faster if system only loaded with few tasks. System with RTOS has won from interrupt in case (1, but lose to interrupt in case (2.

  14. A randomized controlled trial of daily sedation interruption in critically ill children

    NARCIS (Netherlands)

    N.J. Vet (Nienke); S.N. de Wildt (Saskia); C.W.M. Verlaat (Carin); C.A.J. Knibbe (Catherijne); M.G. Mooij (Miriam); J.B. van Woensel (Job); J.M. van Rosmalen (Joost); D. Tibboel (Dick); M. de Hoog (Matthijs)

    2016-01-01

    textabstractPurpose: To compare daily sedation interruption plus protocolized sedation (DSI + PS) to protocolized sedation only (PS) in critically ill children. Methods: In this multicenter randomized controlled trial in three pediatric intensive care units in the Netherlands, mechanically

  15. Reward, interrupted: Inhibitory control and its relevance to addictions.

    Science.gov (United States)

    Jentsch, James David; Pennington, Zachary T

    2014-01-01

    There are broad individual differences in the ability to voluntarily and effortfully suppress motivated, reward-seeking behaviors, and this review presents the hypothesis that these individual differences are relevant to addictive disorders. On one hand, cumulative experience with drug abuse appears to alter the molecular, cellular and circuit mechanisms that mediate inhibitory abilities, leading to increasingly uncontrolled patterns of drug-seeking and -taking. On the other, native inter-individual differences in inhibitory control are apparently a risk factor for aspects of drug-reinforced responding and substance use disorders. In both cases, the behavioral manifestation of poor inhibitory abilities is linked to relatively low striatal dopamine D2-like receptor availability, and evidence is accumulating for a more direct contribution of striatopallidal neurons to cognitive control processes. Mechanistic research is now identifying genes upstream of dopamine transmission that mediate these relationships, as well as the involvement of other neurotransmitter systems, acting alone and in concert with dopamine. The reviewed research stands poised to identify new mechanisms that can be targeted by pharmacotherapies and/or by behavioral interventions that are designed to prevent or treat addictive behaviors and associated behavioral pathology. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Using machine learning to identify structural breaks in single-group interrupted time series designs.

    Science.gov (United States)

    Linden, Ariel; Yarnold, Paul R

    2016-12-01

    Single-group interrupted time series analysis (ITSA) is a popular evaluation methodology in which a single unit of observation is being studied, the outcome variable is serially ordered as a time series and the intervention is expected to 'interrupt' the level and/or trend of the time series, subsequent to its introduction. Given that the internal validity of the design rests on the premise that the interruption in the time series is associated with the introduction of the treatment, treatment effects may seem less plausible if a parallel trend already exists in the time series prior to the actual intervention. Thus, sensitivity analyses should focus on detecting structural breaks in the time series before the intervention. In this paper, we introduce a machine-learning algorithm called optimal discriminant analysis (ODA) as an approach to determine if structural breaks can be identified in years prior to the initiation of the intervention, using data from California's 1988 voter-initiated Proposition 99 to reduce smoking rates. The ODA analysis indicates that numerous structural breaks occurred prior to the actual initiation of Proposition 99 in 1989, including perfect structural breaks in 1983 and 1985, thereby casting doubt on the validity of treatment effects estimated for the actual intervention when using a single-group ITSA design. Given the widespread use of ITSA for evaluating observational data and the increasing use of machine-learning techniques in traditional research, we recommend that structural break sensitivity analysis is routinely incorporated in all research using the single-group ITSA design. © 2016 John Wiley & Sons, Ltd.

  17. Photolytic interruptions of the bacteriorhodopsin photocycle examined by time-resolved resonance raman spectroscopy.

    Science.gov (United States)

    Grieger, I; Atkinson, G H

    1985-09-24

    An investigation of the photolytic conditions used to initiate and spectroscopically monitor the bacteriorhodopsin (BR) photocycle utilizing time-resolved resonance Raman (TR3) spectroscopy has revealed and characterized two photoinduced reactions that interrupt the thermal pathway. One reaction involves the photolytic interconversion of M-412 and M', and the other involves the direct photolytic conversion of the BR-570/K-590 photostationary mixture either to M-412 and M' or to M-like intermediates within 10 ns. The photolytic threshold conditions describing both reactions have been quantitatively measured and are discussed in terms of experimental parameters.

  18. BED-time charts and their application to the problems of interruptions in external beam radiotherapy treatments

    International Nuclear Information System (INIS)

    Sinclair, Judith A.; Oates, Jason P.; Dale, Roger G.

    1999-01-01

    Purpose: The use of radiobiological modelling to examine the likely consequences of interruptions to radiotherapy schedules and to assess various compensatory measures. Methods and Materials: An effect-time graphical display, the BED-time chart, has been developed using the linear-quadratic (LQ) model. This is used to examine the effects on tumour and normal tissues of treatment interruption scenarios representative of clinical situations. The mathematical criteria governing successful salvage have also been drafted and applied to typical situations. Results: The successful salvage of an interrupted treatment is dependent on a number of interacting factors and the method presented here can be used to examine the trade-offs that exist. Although the mathematics may be complex, it is shown that the dilemmas posed by an interrupted treatment may be more easily appreciated with reference to BED-time charts. These may therefore have a useful role as a teaching aid for portraying a wider variety of radiotherapy problems and also in the documentation of interruptions to treatment and the measures taken to compensate for them. Conclusions: Interruptions to radiotherapy regimes are undesirable and compensatory measures need to be initiated as soon as possible after the gap, with a view to completing the amended treatment within the originally prescribed treatment time. Adequate compensation is particularly difficult for long gaps and gaps which occur towards the end of the scheduled treatment. Modelling exercises can help establish guidelines on the available windows of opportunity

  19. Direct Load Control (DLC) Considering Nodal Interrupted Energy Assessment Rate (NIEAR) in Restructured Power Systems

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Wang, Peng; Goel, Lalit

    2010-01-01

    is used as the bids from the ACL customers, is utilized to determine the direct monetary compensation to the ACL customers. The proposed scheme was investigated for the PoolCo electricity market. The optimal DLC scheme is determined based on the minimum system operating cost which is comprised......A direct load control (DLC) scheme of air conditioning loads (ACL) considering direct monetary compensation to ACL customers for the service interruption caused by the DLC program is proposed in this paper for restructured power systems. The nodal interrupted energy assessment rate (NIEAR), which...... of the system energy cost, the system spinning reserve cost and the compensation cost to the ACL customers. Dynamic programming (DP) was used to obtain the optimal DLC scheme. The IEEE reliability test system (RTS) was studied to illustrate the proposed DLC scheme....

  20. Graphical Data Analysis on the Circle: Wrap-Around Time Series Plots for (Interrupted) Time Series Designs.

    Science.gov (United States)

    Rodgers, Joseph Lee; Beasley, William Howard; Schuelke, Matthew

    2014-01-01

    Many data structures, particularly time series data, are naturally seasonal, cyclical, or otherwise circular. Past graphical methods for time series have focused on linear plots. In this article, we move graphical analysis onto the circle. We focus on 2 particular methods, one old and one new. Rose diagrams are circular histograms and can be produced in several different forms using the RRose software system. In addition, we propose, develop, illustrate, and provide software support for a new circular graphical method, called Wrap-Around Time Series Plots (WATS Plots), which is a graphical method useful to support time series analyses in general but in particular in relation to interrupted time series designs. We illustrate the use of WATS Plots with an interrupted time series design evaluating the effect of the Oklahoma City bombing on birthrates in Oklahoma County during the 10 years surrounding the bombing of the Murrah Building in Oklahoma City. We compare WATS Plots with linear time series representations and overlay them with smoothing and error bands. Each method is shown to have advantages in relation to the other; in our example, the WATS Plots more clearly show the existence and effect size of the fertility differential.

  1. Using forecast modelling to evaluate treatment effects in single-group interrupted time series analysis.

    Science.gov (United States)

    Linden, Ariel

    2018-05-11

    Interrupted time series analysis (ITSA) is an evaluation methodology in which a single treatment unit's outcome is studied serially over time and the intervention is expected to "interrupt" the level and/or trend of that outcome. ITSA is commonly evaluated using methods which may produce biased results if model assumptions are violated. In this paper, treatment effects are alternatively assessed by using forecasting methods to closely fit the preintervention observations and then forecast the post-intervention trend. A treatment effect may be inferred if the actual post-intervention observations diverge from the forecasts by some specified amount. The forecasting approach is demonstrated using the effect of California's Proposition 99 for reducing cigarette sales. Three forecast models are fit to the preintervention series-linear regression (REG), Holt-Winters (HW) non-seasonal smoothing, and autoregressive moving average (ARIMA)-and forecasts are generated into the post-intervention period. The actual observations are then compared with the forecasts to assess intervention effects. The preintervention data were fit best by HW, followed closely by ARIMA. REG fit the data poorly. The actual post-intervention observations were above the forecasts in HW and ARIMA, suggesting no intervention effect, but below the forecasts in the REG (suggesting a treatment effect), thereby raising doubts about any definitive conclusion of a treatment effect. In a single-group ITSA, treatment effects are likely to be biased if the model is misspecified. Therefore, evaluators should consider using forecast models to accurately fit the preintervention data and generate plausible counterfactual forecasts, thereby improving causal inference of treatment effects in single-group ITSA studies. © 2018 John Wiley & Sons, Ltd.

  2. Interrupted time-series analysis of regulations to reduce paracetamol (acetaminophen poisoning.

    Directory of Open Access Journals (Sweden)

    Oliver W Morgan

    2007-04-01

    Full Text Available Paracetamol (acetaminophen poisoning is the leading cause of acute liver failure in Great Britain and the United States. Successful interventions to reduced harm from paracetamol poisoning are needed. To achieve this, the government of the United Kingdom introduced legislation in 1998 limiting the pack size of paracetamol sold in shops. Several studies have reported recent decreases in fatal poisonings involving paracetamol. We use interrupted time-series analysis to evaluate whether the recent fall in the number of paracetamol deaths is different to trends in fatal poisoning involving aspirin, paracetamol compounds, antidepressants, or nondrug poisoning suicide.We calculated directly age-standardised mortality rates for paracetamol poisoning in England and Wales from 1993 to 2004. We used an ordinary least-squares regression model divided into pre- and postintervention segments at 1999. The model included a term for autocorrelation within the time series. We tested for changes in the level and slope between the pre- and postintervention segments. To assess whether observed changes in the time series were unique to paracetamol, we compared against poisoning deaths involving compound paracetamol (not covered by the regulations, aspirin, antidepressants, and nonpoisoning suicide deaths. We did this comparison by calculating a ratio of each comparison series with paracetamol and applying a segmented regression model to the ratios. No change in the ratio level or slope indicated no difference compared to the control series. There were about 2,200 deaths involving paracetamol. The age-standardised mortality rate rose from 8.1 per million in 1993 to 8.8 per million in 1997, subsequently falling to about 5.3 per million in 2004. After the regulations were introduced, deaths dropped by 2.69 per million (p = 0.003. Trends in the age-standardised mortality rate for paracetamol compounds, aspirin, and antidepressants were broadly similar to paracetamol

  3. Real-Time Predictions of Reservoir Size and Rebound Time during Antiretroviral Therapy Interruption Trials for HIV.

    Directory of Open Access Journals (Sweden)

    Alison L Hill

    2016-04-01

    Full Text Available Monitoring the efficacy of novel reservoir-reducing treatments for HIV is challenging. The limited ability to sample and quantify latent infection means that supervised antiretroviral therapy (ART interruption studies are generally required. Here we introduce a set of mathematical and statistical modeling tools to aid in the design and interpretation of ART-interruption trials. We show how the likely size of the remaining reservoir can be updated in real-time as patients continue off treatment, by combining the output of laboratory assays with insights from models of reservoir dynamics and rebound. We design an optimal schedule for viral load sampling during interruption, whereby the frequency of follow-up can be decreased as patients continue off ART without rebound. While this scheme can minimize costs when the chance of rebound between visits is low, we find that the reservoir will be almost completely reseeded before rebound is detected unless sampling occurs at least every two weeks and the most sensitive viral load assays are used. We use simulated data to predict the clinical trial size needed to estimate treatment effects in the face of highly variable patient outcomes and imperfect reservoir assays. Our findings suggest that large numbers of patients-between 40 and 150-will be necessary to reliably estimate the reservoir-reducing potential of a new therapy and to compare this across interventions. As an example, we apply these methods to the two "Boston patients", recipients of allogeneic hematopoietic stem cell transplants who experienced large reductions in latent infection and underwent ART-interruption. We argue that the timing of viral rebound was not particularly surprising given the information available before treatment cessation. Additionally, we show how other clinical data can be used to estimate the relative contribution that remaining HIV+ cells in the recipient versus newly infected cells from the donor made to the

  4. Examining the Internal Validity and Statistical Precision of the Comparative Interrupted Time Series Design by Comparison with a Randomized Experiment

    Science.gov (United States)

    St.Clair, Travis; Cook, Thomas D.; Hallberg, Kelly

    2014-01-01

    Although evaluators often use an interrupted time series (ITS) design to test hypotheses about program effects, there are few empirical tests of the design's validity. We take a randomized experiment on an educational topic and compare its effects to those from a comparative ITS (CITS) design that uses the same treatment group as the experiment…

  5. The Validity and Precision of the Comparative Interrupted Time-Series Design: Three Within-Study Comparisons

    Science.gov (United States)

    St. Clair, Travis; Hallberg, Kelly; Cook, Thomas D.

    2016-01-01

    We explore the conditions under which short, comparative interrupted time-series (CITS) designs represent valid alternatives to randomized experiments in educational evaluations. To do so, we conduct three within-study comparisons, each of which uses a unique data set to test the validity of the CITS design by comparing its causal estimates to…

  6. Effect of an evidence-based website on healthcare usage: an interrupted time-series study

    Science.gov (United States)

    Spoelman, Wouter A; Bonten, Tobias N; de Waal, Margot W M; Drenthen, Ton; Smeele, Ivo J M; Nielen, Markus M J; Chavannes, Niels H

    2016-01-01

    Objectives Healthcare costs and usage are rising. Evidence-based online health information may reduce healthcare usage, but the evidence is scarce. The objective of this study was to determine whether the release of a nationwide evidence-based health website was associated with a reduction in healthcare usage. Design Interrupted time series analysis of observational primary care data of healthcare use in the Netherlands from 2009 to 2014. Setting General community primary care. Population 912 000 patients who visited their general practitioners 18.1 million times during the study period. Intervention In March 2012, an evidence-based health information website was launched by the Dutch College of General Practitioners. It was easily accessible and understandable using plain language. At the end of the study period, the website had 2.9 million unique page views per month. Main outcomes measures Primary outcome was the change in consultation rate (consultations/1000 patients/month) before and after the release of the website. Additionally, a reference group was created by including consultations about topics not being viewed at the website. Subgroup analyses were performed for type of consultations, sex, age and socioeconomic status. Results After launch of the website, the trend in consultation rate decreased with 1.620 consultations/1000 patients/month (p<0.001). This corresponds to a 12% decline in consultations 2 years after launch of the website. The trend in consultation rate of the reference group showed no change. The subgroup analyses showed a specific decline for consultations by phone and were significant for all other subgroups, except for the youngest age group. Conclusions Healthcare usage decreased by 12% after providing high-quality evidence-based online health information. These findings show that e-Health can be effective to improve self-management and reduce healthcare usage in times of increasing healthcare costs. PMID:28186945

  7. Effect of an evidence-based website on healthcare usage: an interrupted time-series study.

    Science.gov (United States)

    Spoelman, Wouter A; Bonten, Tobias N; de Waal, Margot W M; Drenthen, Ton; Smeele, Ivo J M; Nielen, Markus M J; Chavannes, Niels H

    2016-11-09

    Healthcare costs and usage are rising. Evidence-based online health information may reduce healthcare usage, but the evidence is scarce. The objective of this study was to determine whether the release of a nationwide evidence-based health website was associated with a reduction in healthcare usage. Interrupted time series analysis of observational primary care data of healthcare use in the Netherlands from 2009 to 2014. General community primary care. 912 000 patients who visited their general practitioners 18.1 million times during the study period. In March 2012, an evidence-based health information website was launched by the Dutch College of General Practitioners. It was easily accessible and understandable using plain language. At the end of the study period, the website had 2.9 million unique page views per month. Primary outcome was the change in consultation rate (consultations/1000 patients/month) before and after the release of the website. Additionally, a reference group was created by including consultations about topics not being viewed at the website. Subgroup analyses were performed for type of consultations, sex, age and socioeconomic status. After launch of the website, the trend in consultation rate decreased with 1.620 consultations/1000 patients/month (pHealthcare usage decreased by 12% after providing high-quality evidence-based online health information. These findings show that e-Health can be effective to improve self-management and reduce healthcare usage in times of increasing healthcare costs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Evaluating the impact of flexible alcohol trading hours on violence: an interrupted time series analysis.

    Directory of Open Access Journals (Sweden)

    David K Humphreys

    Full Text Available On November 24(th 2005, the Government of England and Wales removed regulatory restrictions on the times at which licensed premises could sell alcohol. This study tests availability theory by treating the implementation of Licensing Act (2003 as a natural experiment in alcohol policy.An interrupted time series design was employed to estimate the Act's immediate and delayed impact on violence in the City of Manchester (Population 464,200. We collected police recorded rates of violence, robbery, and total crime between the 1st of February 2004 and the 31st of December 2007. Events were aggregated by week, yielding a total of 204 observations (95 pre-, and 109 post-intervention. Secondary analysis examined changes in daily patterns of violence. Pre- and post-intervention events were separated into four three-hour segments 18∶00-20∶59, 21∶00-23.59, 00∶00-02∶59, 03∶00-05∶59.Analysis found no evidence that the Licensing Act (2003 affected the overall volume of violence. However, analyses of night-time violence found a gradual and permanent shift of weekend violence into later parts of the night. The results estimated an initial increase of 27.5% between 03∶00 to 06∶00 (ω = 0.2433, 95% CI = 0.06, 0.42, which increased to 36% by the end of the study period (δ = -0.897, 95% CI = -1.02, -0.77.This study found no evidence that a national policy increasing the physical availability of alcohol affected the overall volume of violence. There was, however, evidence suggesting that the policy may be associated with changes to patterns of violence in the early morning (3 a.m. to 6 a.m..

  9. A knowledge translation tool improved osteoporosis disease management in primary care: an interrupted time series analysis.

    Science.gov (United States)

    Kastner, Monika; Sawka, Anna M; Hamid, Jemila; Chen, Maggie; Thorpe, Kevin; Chignell, Mark; Ewusie, Joycelyne; Marquez, Christine; Newton, David; Straus, Sharon E

    2014-09-25

    Osteoporosis affects over 200 million people worldwide at a high cost to healthcare systems, yet gaps in management still exist. In response, we developed a multi-component osteoporosis knowledge translation (Op-KT) tool involving a patient-initiated risk assessment questionnaire (RAQ), which generates individualized best practice recommendations for physicians and customized education for patients at the point of care. The objective of this study was to evaluate the effectiveness of the Op-KT tool for appropriate disease management by physicians. The Op-KT tool was evaluated using an interrupted time series design. This involved multiple assessments of the outcomes 12 months before (baseline) and 12 months after tool implementation (52 data points in total). Inclusion criteria were family physicians and their patients at risk for osteoporosis (women aged ≥ 50 years, men aged ≥ 65 years). Primary outcomes were the initiation of appropriate osteoporosis screening and treatment. Analyses included segmented linear regression modeling and analysis of variance. The Op-KT tool was implemented in three family practices in Ontario, Canada representing 5 family physicians with 2840 age eligible patients (mean age 67 years; 76% women). Time series regression models showed an overall increase from baseline in the initiation of screening (3.4%; P management addressed by their physician. Study limitations included the inherent susceptibility of our design compared with a randomized trial. The multicomponent Op-KT tool significantly increased osteoporosis investigations in three family practices, and highlights its potential to facilitate patient self-management. Next steps include wider implementation and evaluation of the tool in primary care.

  10. Improving prehospital trauma care in Rwanda through continuous quality improvement: an interrupted time series analysis.

    Science.gov (United States)

    Scott, John W; Nyinawankusi, Jeanne D'Arc; Enumah, Samuel; Maine, Rebecca; Uwitonze, Eric; Hu, Yihan; Kabagema, Ignace; Byiringiro, Jean Claude; Riviello, Robert; Jayaraman, Sudha

    2017-07-01

    Injury is a major cause of premature death and disability in East Africa, and high-quality pre-hospital care is essential for optimal trauma outcomes. The Rwandan pre-hospital emergency care service (SAMU) uses an electronic database to evaluate and optimize pre-hospital care through a continuous quality improvement programme (CQIP), beginning March 2014. The SAMU database was used to assess pre-hospital quality metrics including supplementary oxygen for hypoxia (O2), intravenous fluids for hypotension (IVF), cervical collar placement for head injuries (c-collar), and either splinting (splint) or administration of pain medications (pain) for long bone fractures. Targets of >90% were set for each metric and daily team meetings and monthly feedback sessions were implemented to address opportunities for improvement. These five pre-hospital quality metrics were assessed monthly before and after implementation of the CQIP. Met and unmet needs for O2, IVF, and c-collar were combined into a summative monthly SAMU Trauma Quality Scores (STQ score). An interrupted time series linear regression model compared the STQ score during 14 months before the CQIP implementation to the first 14 months after. During the 29-month study period 3,822 patients met study criteria. 1,028 patients needed one or more of the five studied interventions during the study period. All five endpoints had a significant increase between the pre-CQI and post-CQI periods (pRwanda. This programme may be used as an example for additional efforts engaging frontline staff with real-time data feedback in order to rapidly translate data collection efforts into improved care for the injured in a resource-limited setting. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The effects of pay for performance on disparities in stroke, hypertension, and coronary heart disease management: interrupted time series study.

    Science.gov (United States)

    Lee, John Tayu; Netuveli, Gopalakrishnan; Majeed, Azeem; Millett, Christopher

    2011-01-01

    The Quality and Outcomes Framework (QOF), a major pay-for-performance programme, was introduced into United Kingdom primary care in April 2004. The impact of this programme on disparities in health care remains unclear. This study examines the following questions: has this pay for performance programme improved the quality of care for coronary heart disease, stroke and hypertension in white, black and south Asian patients? Has this programme reduced disparities in the quality of care between these ethnic groups? Did general practices with different baseline performance respond differently to this programme? Retrospective cohort study of patients registered with family practices in Wandsworth, London during 2007. Segmented regression analysis of interrupted time series was used to take into account the previous time trend. Primary outcome measures were mean systolic and diastolic blood pressure, and cholesterol levels. Our findings suggest that the implementation of QOF resulted in significant short term improvements in blood pressure control. The magnitude of benefit varied between ethnic groups with a statistically significant short term reduction in systolic BP in white and black but not in south Asian patients with hypertension. Disparities in risk factor control were attenuated only on few measures and largely remained intact at the end of the study period. Pay for performance programmes such as the QOF in the UK should set challenging but achievable targets. Specific targets aimed at reducing ethnic disparities in health care may also be needed.

  12. Optogenetic control of thalamus as a tool for interrupting penicillin induced seizures.

    Science.gov (United States)

    Han, Yechao; Ma, Feiqiang; Li, Hongbao; Wang, Yueming; Xu, Kedi

    2015-01-01

    Penicillin epilepsy model, whose discharge resembles that of human absence epilepsy, is one of the most useful acute experimental epilepsy models. Though closed-loop optogenetic strategy of interrupting seizures was proved sufficient to switch off epilepsy by controlling thalamus in the post-lesion partial chronic epilepsy model, doubts still exist in absence epilepsy attenuation through silencing thalamus. Here we directly arrested the thalamus to modulate penicillin-induced absence seizures through pseudorandom responsive stimulation on eNpHR-transfected rats. Our data suggested that the duration of epileptiform bursts under light conditions, compared with no light conditions, did not increase or decrease when modulated specific eNpHR-expressing neurons in thalamus.

  13. Impact of STROBE statement publication on quality of observational study reporting: interrupted time series versus before-after analysis.

    Directory of Open Access Journals (Sweden)

    Sylvie Bastuji-Garin

    Full Text Available In uncontrolled before-after studies, CONSORT was shown to improve the reporting of randomised trials. Before-after studies ignore underlying secular trends and may overestimate the impact of interventions. Our aim was to assess the impact of the 2007 STROBE statement publication on the quality of observational study reporting, using both uncontrolled before-after analyses and interrupted time series.For this quasi-experimental study, original articles reporting cohort, case-control, and cross-sectional studies published between 2004 and 2010 in the four dermatological journals having the highest 5-year impact factors (≥ 4 were selected. We compared the proportions of STROBE items (STROBE score adequately reported in each article during three periods, two pre STROBE period (2004-2005 and 2006-2007 and one post STROBE period (2008-2010. Segmented regression analysis of interrupted time series was also performed.Of the 456 included articles, 187 (41% reported cohort studies, 166 (36.4% cross-sectional studies, and 103 (22.6% case-control studies. The median STROBE score was 57% (range, 18%-98%. Before-after analysis evidenced significant STROBE score increases between the two pre-STROBE periods and between the earliest pre-STROBE period and the post-STROBE period (median score2004-05 48% versus median score2008-10 58%, p<0.001 but not between the immediate pre-STROBE period and the post-STROBE period (median score2006-07 58% versus median score2008-10 58%, p = 0.42. In the pre STROBE period, the six-monthly mean STROBE score increased significantly, by 1.19% per six-month period (absolute increase 95%CI, 0.26% to 2.11%, p = 0.016. By segmented analysis, no significant changes in STROBE score trends occurred (-0.40%; 95%CI, -2.20 to 1.41; p = 0.64 in the post STROBE statement publication.The quality of reports increased over time but was not affected by STROBE. Our findings raise concerns about the relevance of uncontrolled before

  14. An Interrupted Time-Series Analysis of Durkheim's Social Deregulation Thesis: The Case of the Russian Federation.

    Science.gov (United States)

    Pridemore, William Alex; Chamlin, Mitchell B; Cochran, John K

    2007-06-01

    The dissolution of the Soviet Union resulted in sudden, widespread, and fundamental changes to Russian society. The former social welfare system-with its broad guarantees of employment, healthcare, education, and other forms of social support-was dismantled in the shift toward democracy, rule of law, and a free-market economy. This unique natural experiment provides a rare opportunity to examine the potentially disintegrative effects of rapid social change on deviance, and thus to evaluate one of Durkheim's core tenets. We took advantage of this opportunity by performing interrupted time-series analyses of annual age-adjusted homicide, suicide, and alcohol-related mortality rates for the Russian Federation using data from 1956 to 2002, with 1992-2002 as the postintervention time-frame. The ARIMA models indicate that, controlling for the long-term processes that generated these three time series, the breakup of the Soviet Union was associated with an appreciable increase in each of the cause-of-death rates. We interpret these findings as being consistent with the Durkheimian hypothesis that rapid social change disrupts social order, thereby increasing the level of crime and deviance.

  15. An Interrupted Time-Series Analysis of Durkheim's Social Deregulation Thesis: The Case of the Russian Federation

    Science.gov (United States)

    Pridemore, William Alex; Chamlin, Mitchell B.; Cochran, John K.

    2009-01-01

    The dissolution of the Soviet Union resulted in sudden, widespread, and fundamental changes to Russian society. The former social welfare system-with its broad guarantees of employment, healthcare, education, and other forms of social support-was dismantled in the shift toward democracy, rule of law, and a free-market economy. This unique natural experiment provides a rare opportunity to examine the potentially disintegrative effects of rapid social change on deviance, and thus to evaluate one of Durkheim's core tenets. We took advantage of this opportunity by performing interrupted time-series analyses of annual age-adjusted homicide, suicide, and alcohol-related mortality rates for the Russian Federation using data from 1956 to 2002, with 1992-2002 as the postintervention time-frame. The ARIMA models indicate that, controlling for the long-term processes that generated these three time series, the breakup of the Soviet Union was associated with an appreciable increase in each of the cause-of-death rates. We interpret these findings as being consistent with the Durkheimian hypothesis that rapid social change disrupts social order, thereby increasing the level of crime and deviance. PMID:20165565

  16. Immune control of HIV-1 infection after therapy interruption: immediate versus deferred antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Bernaschi Massimo

    2009-10-01

    Full Text Available Abstract Background The optimal stage for initiating antiretroviral therapies in HIV-1 bearing patients is still a matter of debate. Methods We present computer simulations of HIV-1 infection aimed at identifying the pro et contra of immediate as compared to deferred Highly Active Antiretroviral Therapy (HAART. Results Our simulations highlight that a prompt specific CD8+ cytotoxic T lymphocytes response is detected when therapy is delayed. Compared to very early initiation of HAART, in deferred treated patients CD8+ T cells manage to mediate the decline of viremia in a shorter time and, at interruption of therapy, the virus experiences a stronger immune pressure. We also observe, however, that the immunological effects of the therapy fade with time in both therapeutic regimens. Thus, within one year from discontinuation, viral burden recovers to the value at which it would level off in the absence of therapy. In summary, simulations show that immediate therapy does not prolong the disease-free period and does not confer a survival benefit when compared to treatment started during the chronic infection phase. Conclusion Our conclusion is that, since there is no therapy to date that guarantees life-long protection, deferral of therapy should be preferred in order to minimize the risk of adverse effects, the occurrence of drug resistances and the costs of treatment.

  17. Impact of a COPD discharge care bundle on readmissions following admission with acute exacerbation: interrupted time series analysis.

    Directory of Open Access Journals (Sweden)

    Anthony A Laverty

    Full Text Available We evaluated the impact of a COPD discharge care bundle on readmission rates following hospitalisation with an acute exacerbation.Interrupted time series analysis, comparing readmission rates for COPD exacerbations at nine trusts that introduced the bundle, to two comparison groups; (1 other NHS trusts in London and (2 all other NHS trusts in England. Care bundles were implemented at different times for different NHS trusts, ranging from October 2009 to April 2011.Nine NHS acute trusts in the London, England.Patients aged 45 years and older admitted to an NHS acute hospital in England for acute exacerbation of COPD. Data come from Hospital Episode Statistics, April 2002 to March 2012.Annual trend readmission rates (and in total bed days within 7, 28 and 90 days, before and after implementation.In hospitals introducing the bundle readmission rates were rising before implementation and falling afterwards (e.g. readmissions within 28 days +2.13% per annum (pa pre and -5.32% pa post (p for difference in trends = 0.012. Following implementation, readmission rates within 7 and 28 day were falling faster than among other trusts in London, although this was not statistically significant (e.g. readmissions within 28 days -4.6% pa vs. -3.2% pa, p = 0.44. Comparisons with a national control group were similar.The COPD discharge care bundle appeared to be associated with a reduction in readmission rate among hospitals using it. The significance of this is unclear because of changes to background trends in London and nationally.

  18. Multifaceted academic detailing program to increase pharmacotherapy for alcohol use disorder: interrupted time series evaluation of effectiveness.

    Science.gov (United States)

    Harris, Alex H S; Bowe, Thomas; Hagedorn, Hildi; Nevedal, Andrea; Finlay, Andrea K; Gidwani, Risha; Rosen, Craig; Kay, Chad; Christopher, Melissa

    2016-09-15

    Active consideration of effective medications to treat alcohol use disorder (AUD) is a consensus standard of care, yet knowledge and use of these medications are very low across diverse settings. This study evaluated the overall effectiveness a multifaceted academic detailing program to address this persistent quality problem in the US Veterans Health Administration (VHA), as well as the context and process factors that explained variation in effectiveness across sites. An interrupted time series design, analyzed with mixed-effects segmented logistic regression, was used to evaluate changes in level and rate of change in the monthly percent of patients with a clinically documented AUD who received naltrexone, acamprosate, disulfiram, or topiramate. Using data from a 20 month post-implementation period, intervention sites (n = 37) were compared to their own 16 month pre-implementation performance and separately to the rest of VHA. From immediately pre-intervention to the end of the observation period, the percent of patients in the intervention sites with AUD who received medication increased over 3.4 % in absolute terms and 68 % in relative terms (i.e., 4.9-8.3 %). This change was significant compared to the pre-implementation period in the intervention sites and secular trends in control sites. Sites with lower pre-implementation adoption, more person hours of detailing, but fewer people detailed, had larger immediate increases in medication receipt after implementation. The average number of detailing encounters per person was associated with steeper increases in slope over time. This study found empirical support for a multifaceted quality improvement strategy aimed at increasing access to and utilization of pharmacotherapy for AUD. Future studies should focus on determining how to enhance the programs effects, especially in non-responsive locations.

  19. Measuring Quality Improvement in Acute Ischemic Stroke Care: Interrupted Time Series Analysis of Door-to-Needle Time

    Directory of Open Access Journals (Sweden)

    Anne Margreet van Dishoeck

    2014-06-01

    Full Text Available Background: In patients with acute ischemic stroke, early treatment with recombinant tissue plasminogen activator (rtPA improves functional outcome by effectively reducing disability and dependency. Timely thrombolysis, within 1 h, is a vital aspect of acute stroke treatment, and is reflected in the widely used performance indicator ‘door-to-needle time' (DNT. DNT measures the time from the moment the patient enters the emergency department until he/she receives intravenous rtPA. The purpose of the study was to measure quality improvement from the first implementation of thrombolysis in stroke patients in a university hospital in the Netherlands. We further aimed to identify specific interventions that affect DNT. Methods: We included all patients with acute ischemic stroke consecutively admitted to a large university hospital in the Netherlands between January 2006 and December 2012, and focused on those treated with thrombolytic therapy on admission. Data were collected routinely for research purposes and internal quality measurement (the Erasmus Stroke Study. We used a retrospective interrupted time series design to study the trend in DNT, analyzed by means of segmented regression. Results: Between January 2006 and December 2012, 1,703 patients with ischemic stroke were admitted and 262 (17% were treated with rtPA. Patients treated with thrombolysis were on average 63 years old at the time of the stroke and 52% were male. Mean age (p = 0.58 and sex distribution (p = 0.98 did not change over the years. The proportion treated with thrombolysis increased from 5% in 2006 to 22% in 2012. In 2006, none of the patients were treated within 1 h. In 2012, this had increased to 81%. In a logistic regression analysis, this trend was significant (OR 1.6 per year, CI 1.4-1.8. The median DNT was reduced from 75 min in 2006 to 45 min in 2012 (p Conclusion and Implications: The DNT steadily improved from the first implementation of thrombolysis. Specific

  20. Network interruptions

    CERN Multimedia

    2005-01-01

    On Sunday 12 June 2005, a site-wide security software upgrade will be performed on all CERN network equipment. This maintenance operation will cause at least 2 short network interruptions of 2 minutes on each equipment item. There are hundreds of such items across the CERN site (Meyrin, Prévessin and all SPS and LHC pits), and it will thus take the whole day to treat them all. All network users and services will be affected. Central batch computing services will be interrupted during this period, expected to last from 8 a.m. until late evening. Job submission will still be possible but no jobs will actually be run. It is hoped to complete the computer centre upgrades in the morning so that stable access can be restored to lxplus, afs and nice services as soon as possible; this cannot be guaranteed, however. The opportunity will be used to interrupt and perform upgrades on the CERN Document Servers.

  1. The effect of the late 2000s financial crisis on suicides in Spain: an interrupted time-series analysis.

    Science.gov (United States)

    Lopez Bernal, James A; Gasparrini, Antonio; Artundo, Carlos M; McKee, Martin

    2013-10-01

    The current financial crisis is having a major impact on European economies, especially that of Spain. Past evidence suggests that adverse macro-economic conditions exacerbate mental illness, but evidence from the current crisis is limited. This study analyses the association between the financial crisis and suicide rates in Spain. An interrupted time-series analysis of national suicides data between 2005 and 2010 was used to establish whether there has been any deviation in the underlying trend in suicide rates associated with the financial crisis. Segmented regression with a seasonally adjusted quasi-Poisson model was used for the analysis. Stratified analyses were performed to establish whether the effect of the crisis on suicides varied by region, sex and age group. The mean monthly suicide rate in Spain during the study period was 0.61 per 100 000 with an underlying trend of a 0.3% decrease per month. We found an 8.0% increase in the suicide rate above this underlying trend since the financial crisis (95% CI: 1.009-1.156; P = 0.03); this was robust to sensitivity analysis. A control analysis showed no change in deaths from accidental falls associated with the crisis. Stratified analyses suggested that the association between the crisis and suicide rates is greatest in the Mediterranean and Northern areas, in males and amongst those of working age. The financial crisis in Spain has been associated with a relative increase in suicides. Males and those of working age may be at particular risk of suicide associated with the crisis and may benefit from targeted interventions.

  2. Effect of a population-level performance dashboard intervention on maternal-newborn outcomes: an interrupted time series study.

    Science.gov (United States)

    Weiss, Deborah; Dunn, Sandra I; Sprague, Ann E; Fell, Deshayne B; Grimshaw, Jeremy M; Darling, Elizabeth; Graham, Ian D; Harrold, JoAnn; Smith, Graeme N; Peterson, Wendy E; Reszel, Jessica; Lanes, Andrea; Walker, Mark C; Taljaard, Monica

    2018-06-01

    To assess the effect of the Maternal Newborn Dashboard on six key clinical performance indicators in the province of Ontario, Canada. Interrupted time series using population-based data from the provincial birth registry covering a 3-year period before implementation of the Dashboard and 2.5 years after implementation (November 2009 through March 2015). All hospitals in the province of Ontario providing maternal-newborn care (n=94). A hospital-based online audit and feedback programme. Rates of the six performance indicators included in the Dashboard. 2.5 years after implementation, the audit and feedback programme was associated with statistically significant absolute decreases in the rates of episiotomy (decrease of 1.5 per 100 women, 95% CI 0.64 to 2.39), induction for postdates in women who were less than 41 weeks at delivery (decrease of 11.7 per 100 women, 95% CI 7.4 to 16.0), repeat caesarean delivery in low-risk women performed before 39 weeks (decrease of 10.4 per 100 women, 95% CI 9.3 to 11.5) and an absolute increase in the rate of appropriately timed group B streptococcus screening (increase of 2.8 per 100, 95% CI 2.2 to 3.5). The audit and feedback programme did not significantly affect the rates of unsatisfactory newborn screening blood samples or formula supplementation at discharge. No statistically significant effects were observed for the two internal control outcomes or the four external control indicators-in fact, two external control indicators (episiotomy and postdates induction) worsened relative to before implementation. An electronic audit and feedback programme implemented in maternal-newborn hospitals was associated with clinically relevant practice improvements at the provincial level in the majority of targeted indicators. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  3. Interrupting Prolonged Sitting with Regular Activity Breaks does not Acutely Influence Appetite: A Randomised Controlled Trial.

    Science.gov (United States)

    Mete, Evelyn M; Perry, Tracy L; Haszard, Jillian J; Homer, Ashleigh R; Fenemor, Stephen P; Rehrer, Nancy J; Skeaff, C Murray; Peddie, Meredith C

    2018-01-26

    Regular activity breaks increase energy expenditure; however, this may promote compensatory eating behaviour. The present study compared the effects of regular activity breaks and prolonged sitting on appetite. In a randomised, cross-over trial, 36 healthy adults (BMI (Body Mass Index) 23.9 kg/m² (S.D. = 3.9)) completed four, two-day interventions: two with prolonged sitting (SIT), and two with sitting and 2 min of walking every 30 min (RAB). Standardized meals were provided throughout the intervention, with an ad libitum meal at the end of Day 2. Appetite and satiety were assessed throughout both days of each intervention using five visual analogue scales. The five responses were combined into a single appetite response at each time point. The area under the appetite response curve (AUC) was calculated for each day. Intervention effects for appetite response AUC and ad libitum meal intake were tested using linear mixed models. Appetite AUC did not differ between interventions (standardised effect of RAB compared to SIT: Day 1: 0.11; 95% CI: -0.28, 0.06; p = 0.212; Day 2: 0.04; 95% CI: -0.15, 0.24; p = 0.648). There was no significant difference in energy consumed at the ad libitum lunch meal on Day 2 between RAB and SIT. Interrupting prolonged sitting with regular activity breaks does not acutely influence appetite or volume of food consumed, despite inferred increases in energy expenditure. Longer-term investigation into the effects of regular activity breaks on energy balance is warranted.

  4. Interrupting Prolonged Sitting with Regular Activity Breaks does not Acutely Influence Appetite: A Randomised Controlled Trial

    Directory of Open Access Journals (Sweden)

    Evelyn M. Mete

    2018-01-01

    Full Text Available Regular activity breaks increase energy expenditure; however, this may promote compensatory eating behaviour. The present study compared the effects of regular activity breaks and prolonged sitting on appetite. In a randomised, cross-over trial, 36 healthy adults (BMI (Body Mass Index 23.9 kg/m2 (S.D. = 3.9 completed four, two-day interventions: two with prolonged sitting (SIT, and two with sitting and 2 min of walking every 30 min (RAB. Standardized meals were provided throughout the intervention, with an ad libitum meal at the end of Day 2. Appetite and satiety were assessed throughout both days of each intervention using five visual analogue scales. The five responses were combined into a single appetite response at each time point. The area under the appetite response curve (AUC was calculated for each day. Intervention effects for appetite response AUC and ad libitum meal intake were tested using linear mixed models. Appetite AUC did not differ between interventions (standardised effect of RAB compared to SIT: Day 1: 0.11; 95% CI: −0.28, 0.06; p = 0.212; Day 2: 0.04; 95% CI: −0.15, 0.24; p = 0.648. There was no significant difference in energy consumed at the ad libitum lunch meal on Day 2 between RAB and SIT. Interrupting prolonged sitting with regular activity breaks does not acutely influence appetite or volume of food consumed, despite inferred increases in energy expenditure. Longer-term investigation into the effects of regular activity breaks on energy balance is warranted.

  5. A combination of subcuticular suture and sterile Micropore tape compared with conventional interrupted sutures for skin closure. A controlled trial.

    Science.gov (United States)

    Taube, M.; Porter, R. J.; Lord, P. H.

    1983-01-01

    We have conducted a controlled trial to compare skin closure using conventional interrupted sutures with a combination of subcuticular suture and sterile Micropore tape in 169 patients undergoing appendicectomy, inguinal herniorrhaphy, or saphenofemoral ligation. We have found that the combination technique consistently gives a better cosmetic result and that the tape acts well as a dressing, is convenient, and is well tolerated by patients. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6344732

  6. Researches on Nutritional Behaviour in Romanian Black and White Primiparous Cows. Interruptions Number and their Duration in the Ration Consumption Time

    Directory of Open Access Journals (Sweden)

    Silvia Erina

    2012-10-01

    Full Text Available The study was carried out on 9 Romanian Black and White primiparous cows. The aim of this study was todetermine some aspect of nutritional behaviour of the cows. During the experiments, the following behaviour aspectswere determined: interruption number and their duration in the feed consumption time. Results showed that theadministration order of forages had an influence on the interruptions number, which was 0.74 less for hay in fibroussucculentorder (O1. For silage, the interruption number was 0.42 higher in fibrous-succulent order (O1. Betweenportion 1 (P1 and portion 3 (P3, the significant difference (p<0.05 was for interruptions duration, duringconsumption silage, in favour portion P1. Distinct significant differences (p<0.01 was observed for the interruptionnumber during consumption silage (0.95 sec. higher in P1 than in P3, for interruption duration (5.96 sec. higher inP1 than in P3. Between P2 and P3, significant difference (p<0.05 was observed for interruptions number duringconsumption silage and for average interruptions duration during consumption beet in favour to portion P2.Regarding the number of feedings per portion, always the differences were higher in the second feeding F1 than inthe first feeding F2.

  7. Water Supply Interruptions and Suspected Cholera Incidence: A Time-Series Regression in the Democratic Republic of the Congo

    Science.gov (United States)

    Jeandron, Aurélie; Saidi, Jaime Mufitini; Kapama, Alois; Burhole, Manu; Birembano, Freddy; Vandevelde, Thierry; Gasparrini, Antonio; Armstrong, Ben; Cairncross, Sandy; Ensink, Jeroen H. J.

    2015-01-01

    Background The eastern provinces of the Democratic Republic of the Congo have been identified as endemic areas for cholera transmission, and despite continuous control efforts, they continue to experience regular cholera outbreaks that occasionally spread to the rest of the country. In a region where access to improved water sources is particularly poor, the question of which improvements in water access should be prioritized to address cholera transmission remains unresolved. This study aimed at investigating the temporal association between water supply interruptions and Cholera Treatment Centre (CTC) admissions in a medium-sized town. Methods and Findings Time-series patterns of daily incidence of suspected cholera cases admitted to the Cholera Treatment Centre in Uvira in South Kivu Province between 2009 and 2014 were examined in relation to the daily variations in volume of water supplied by the town water treatment plant. Quasi-poisson regression and distributed lag nonlinear models up to 12 d were used, adjusting for daily precipitation rates, day of the week, and seasonal variations. A total of 5,745 patients over 5 y of age with acute watery diarrhoea symptoms were admitted to the CTC over the study period of 1,946 d. Following a day without tap water supply, the suspected cholera incidence rate increased on average by 155% over the next 12 d, corresponding to a rate ratio of 2.55 (95% CI: 1.54–4.24), compared to the incidence experienced after a day with optimal production (defined as the 95th percentile—4,794 m3). Suspected cholera cases attributable to a suboptimal tap water supply reached 23.2% of total admissions (95% CI 11.4%–33.2%). Although generally reporting less admissions to the CTC, neighbourhoods with a higher consumption of tap water were more affected by water supply interruptions, with a rate ratio of 3.71 (95% CI: 1.91–7.20) and an attributable fraction of cases of 31.4% (95% CI: 17.3%–42.5%). The analysis did not suggest any

  8. Water supply interruptions and suspected cholera incidence: a time-series regression in the Democratic Republic of the Congo.

    Science.gov (United States)

    Jeandron, Aurélie; Saidi, Jaime Mufitini; Kapama, Alois; Burhole, Manu; Birembano, Freddy; Vandevelde, Thierry; Gasparrini, Antonio; Armstrong, Ben; Cairncross, Sandy; Ensink, Jeroen H J

    2015-10-01

    The eastern provinces of the Democratic Republic of the Congo have been identified as endemic areas for cholera transmission, and despite continuous control efforts, they continue to experience regular cholera outbreaks that occasionally spread to the rest of the country. In a region where access to improved water sources is particularly poor, the question of which improvements in water access should be prioritized to address cholera transmission remains unresolved. This study aimed at investigating the temporal association between water supply interruptions and Cholera Treatment Centre (CTC) admissions in a medium-sized town. Time-series patterns of daily incidence of suspected cholera cases admitted to the Cholera Treatment Centre in Uvira in South Kivu Province between 2009 and 2014 were examined in relation to the daily variations in volume of water supplied by the town water treatment plant. Quasi-poisson regression and distributed lag nonlinear models up to 12 d were used, adjusting for daily precipitation rates, day of the week, and seasonal variations. A total of 5,745 patients over 5 y of age with acute watery diarrhoea symptoms were admitted to the CTC over the study period of 1,946 d. Following a day without tap water supply, the suspected cholera incidence rate increased on average by 155% over the next 12 d, corresponding to a rate ratio of 2.55 (95% CI: 1.54-4.24), compared to the incidence experienced after a day with optimal production (defined as the 95th percentile-4,794 m3). Suspected cholera cases attributable to a suboptimal tap water supply reached 23.2% of total admissions (95% CI 11.4%-33.2%). Although generally reporting less admissions to the CTC, neighbourhoods with a higher consumption of tap water were more affected by water supply interruptions, with a rate ratio of 3.71 (95% CI: 1.91-7.20) and an attributable fraction of cases of 31.4% (95% CI: 17.3%-42.5%). The analysis did not suggest any association between levels of residual

  9. Just-in-time preemptive single machine problem with costs of earliness/tardiness, interruption and work-in-process

    Directory of Open Access Journals (Sweden)

    Mohammad Kazemi

    2012-04-01

    Full Text Available This paper considers preemption and idle time are allowed in a single machine scheduling problem with just-in-time (JIT approach. It incorporates Earliness/Tardiness (E/T penalties, interruption penalties and holding cost of jobs which are waiting to be processed as work-in-process (WIP. Generally in non-preemptive problems, E/T penalties are a function of the completion time of the jobs. Then, we introduce a non-linear preemptive scheduling model where the earliness penalty depends on the starting time of a job. The model is liberalized by an elaborately–designed procedure to reach the optimum solution. To validate and verify the performance of proposed model, computational results are presented by solving a number of numerical examples.

  10. General bulk service queueing system with N-policy, multiplevacations, setup time and server breakdown without interruption

    Science.gov (United States)

    Sasikala, S.; Indhira, K.; Chandrasekaran, V. M.

    2017-11-01

    In this paper, we have considered an MX / (a,b) / 1 queueing system with server breakdown without interruption, multiple vacations, setup times and N-policy. After a batch of service, if the size of the queue is ξ (customers in the queue. After a vacation, if the server finds at least N customers waiting for service, then the server needs a setup time to start the service. After a batch of service, if the amount of waiting customers in the queue is ξ (≥ a) then the server serves a batch of min(ξ,b) customers, where b ≥ a. We derived the probability generating function of queue length at arbitrary time epoch. Further, we obtained some important performance measures.

  11. Segmented regression analysis of interrupted time series data to assess outcomes of a South American road traffic alcohol policy change.

    Science.gov (United States)

    Nistal-Nuño, Beatriz

    2017-09-01

    In Chile, a new law introduced in March 2012 decreased the legal blood alcohol concentration (BAC) limit for driving while impaired from 1 to 0.8 g/l and the legal BAC limit for driving under the influence of alcohol from 0.5 to 0.3 g/l. The goal is to assess the impact of this new law on mortality and morbidity outcomes in Chile. A review of national databases in Chile was conducted from January 2003 to December 2014. Segmented regression analysis of interrupted time series was used for analyzing the data. In a series of multivariable linear regression models, the change in intercept and slope in the monthly incidence rate of traffic deaths and injuries and association with alcohol per 100,000 inhabitants was estimated from pre-intervention to postintervention, while controlling for secular changes. In nested regression models, potential confounding seasonal effects were accounted for. All analyses were performed at a two-sided significance level of 0.05. Immediate level drops in all the monthly rates were observed after the law from the end of the prelaw period in the majority of models and in all the de-seasonalized models, although statistical significance was reached only in the model for injures related to alcohol. After the law, the estimated monthly rate dropped abruptly by -0.869 for injuries related to alcohol and by -0.859 adjusting for seasonality (P < 0.001). Regarding the postlaw long-term trends, it was evidenced a steeper decreasing trend after the law in the models for deaths related to alcohol, although these differences were not statistically significant. A strong evidence of a reduction in traffic injuries related to alcohol was found following the law in Chile. Although insufficient evidence was found of a statistically significant effect for the beneficial effects seen on deaths and overall injuries, potential clinically important effects cannot be ruled out. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd

  12. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: an interrupted time series over a 10-year period.

    Science.gov (United States)

    Helder, Onno K; Brug, Johannes; van Goudoever, Johannes B; Looman, Caspar W N; Reiss, Irwin K M; Kornelisse, René F

    2014-07-01

    Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. An observational study with an interrupted time series analysis of the occurrence of NBSI was performed in very low-birth weight (VLBW) infants. Interventions consisted of an education program, gain-framed screen saver messages, and an infection prevention week with an introduction on consistent glove use. A total of 1,964 VLBW infants admitted between January 1, 2002, and December 31, 2011, were studied. The proportion of infants with ≥1 NBSI decreased from 47.6%-21.2% (P Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  13. A robust interrupted time series model for analyzing complex health care intervention data

    KAUST Repository

    Cruz, Maricela

    2017-08-29

    Current health policy calls for greater use of evidence-based care delivery services to improve patient quality and safety outcomes. Care delivery is complex, with interacting and interdependent components that challenge traditional statistical analytic techniques, in particular, when modeling a time series of outcomes data that might be

  14. A robust interrupted time series model for analyzing complex health care intervention data

    KAUST Repository

    Cruz, Maricela; Bender, Miriam; Ombao, Hernando

    2017-01-01

    Current health policy calls for greater use of evidence-based care delivery services to improve patient quality and safety outcomes. Care delivery is complex, with interacting and interdependent components that challenge traditional statistical analytic techniques, in particular, when modeling a time series of outcomes data that might be

  15. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: an interrupted time series over a 10-year period

    NARCIS (Netherlands)

    Helder, Onno K.; Brug, Johannes; van Goudoever, Johannes B.; Looman, Caspar W. N.; Reiss, Irwin K. M.; Kornelisse, René F.

    2014-01-01

    Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. An observational study with an interrupted time series

  16. Effect of nocturnal sound reduction on the incidence of delirium in intensive care unit patients: An interrupted time series analysis.

    Science.gov (United States)

    van de Pol, Ineke; van Iterson, Mat; Maaskant, Jolanda

    2017-08-01

    Delirium in critically-ill patients is a common multifactorial disorder that is associated with various negative outcomes. It is assumed that sleep disturbances can result in an increased risk of delirium. This study hypothesized that implementing a protocol that reduces overall nocturnal sound levels improves quality of sleep and reduces the incidence of delirium in Intensive Care Unit (ICU) patients. This interrupted time series study was performed in an adult mixed medical and surgical 24-bed ICU. A pre-intervention group of 211 patients was compared with a post-intervention group of 210 patients after implementation of a nocturnal sound-reduction protocol. Primary outcome measures were incidence of delirium, measured by the Intensive Care Delirium Screening Checklist (ICDSC) and quality of sleep, measured by the Richards-Campbell Sleep Questionnaire (RCSQ). Secondary outcome measures were use of sleep-inducing medication, delirium treatment medication, and patient-perceived nocturnal noise. A significant difference in slope in the percentage of delirium was observed between the pre- and post-intervention periods (-3.7% per time period, p=0.02). Quality of sleep was unaffected (0.3 per time period, p=0.85). The post-intervention group used significantly less sleep-inducing medication (psound-reduction protocol. However, reported sleep quality did not improve. Copyright © 2017. Published by Elsevier Ltd.

  17. Effects of Health Insurance Interruption on Loss of Hypertension Control in Women With and Women Without HIV.

    Science.gov (United States)

    Edmonds, Andrew; Ludema, Christina; Eron, Joseph J; Cole, Stephen R; Adedimeji, Adebola A; Cohen, Mardge H; Cooper, Hannah L; Fischl, Margaret; Johnson, Mallory O; Krause, Denise D; Merenstein, Dan; Milam, Joel; Wilson, Tracey E; Adimora, Adaora A

    2017-12-01

    Among low-income women with and without HIV, it is a priority to reduce age-related comorbidities, including hypertension and its sequelae. Because consistent health insurance access has been identified as an important factor in controlling many chronic diseases, we estimated the effects of coverage interruption on loss of hypertension control in a cohort of women in the United States. We analyzed prospective, longitudinal data from the Women's Interagency HIV Study. HIV-infected and HIV-uninfected women were included between 2005 and 2014 when they reported health insurance at consecutive biannual visits and had controlled hypertension, and were followed for any insurance break and loss of hypertension control. We estimated hazard ratios (HRs) by Cox proportional hazards regression with inverse-probability-of-treatment-and censoring weights (marginal structural models), and plotted the cumulative incidence of hypertension control loss. Among 890 HIV-infected women, the weighted HR for hypertension control loss comparing health insurance interruption to uninterrupted coverage was 1.37 (95% confidence interval [CI], 0.99-1.91). Inclusion of AIDS Drug Assistance Program (ADAP) participation with health insurance modestly increased the HR (1.47; 95% CI, 1.04-2.07). Analysis of 272 HIV-uninfected women yielded a similar HR (1.39; 95% CI, 0.88-2.21). Additionally, there were indications of uninterrupted coverage having a protective effect on hypertension when compared with the natural course in HIV-infected (HR, 0.82; 95% CI, 0.61-1.11) and HIV-uninfected (HR, 0.78; 95% CI, 0.52-1.19) women. This study provides evidence that health insurance continuity promotes hypertension control in key populations. Interventions that ensure coverage stability and ADAP access should be a policy priority.

  18. The driving and controlling techniques of compactPCI bus in VxWorks real-time operating system

    International Nuclear Information System (INIS)

    Li Anzong; Ju Xiaodong; Qiao Wenxiao

    2005-01-01

    CompactPCI bus and interface featuring, the content and function of PCI configuration register are introduced herein. The driving and controlling techniques of CompactPCI bus in VxWorks real-time operating system are detailed. Hardware interrupt handling is one of key significance in real-time systems, because it is usually through interrupts that the system is informed of external events. VxWorks allows C functions to be connected to any interrupt. A routine connected to an interrupt in this way is called an interrupt service routine (ISR). For response of interrupt, interrupt control/status register of PCI 9054 interface chip needs to be set. The general-purpose binary semaphore used in ISR is capable of addressing the requirements of both forms of task coordination: mutual exclusion and synchronization. Therefore, the system runs stably and reliably. (authors)

  19. Incidence of infective endocarditis in England, 2000-13: a secular trend, interrupted time-series analysis.

    Science.gov (United States)

    Dayer, Mark J; Jones, Simon; Prendergast, Bernard; Baddour, Larry M; Lockhart, Peter B; Thornhill, Martin H

    2015-03-28

    Antibiotic prophylaxis given before invasive dental procedures in patients at risk of developing infective endocarditis has historically been the focus of infective endocarditis prevention. Recent changes in antibiotic prophylaxis guidelines in the USA and Europe have substantially reduced the number of patients for whom antibiotic prophylaxis is recommended. In the UK, guidelines from the National Institute for Health and Clinical Excellence (NICE) recommended complete cessation of antibiotic prophylaxis for prevention of infective endocarditis in March, 2008. We aimed to investigate changes in the prescribing of antibiotic prophylaxis and the incidence of infective endocarditis since the introduction of these guidelines. We did a retrospective secular trend study, analysed as an interrupted time series, to investigate the effect of antibiotic prophylaxis versus no prophylaxis on the incidence of infective endocarditis in England. We analysed data for the prescription of antibiotic prophylaxis from Jan 1, 2004, to March 31, 2013, and hospital discharge episode statistics for patients with a primary diagnosis of infective endocarditis from Jan 1, 2000, to March 31, 2013. We compared the incidence of infective endocarditis before and after the introduction of the NICE guidelines using segmented regression analysis of the interrupted time series. Prescriptions of antibiotic prophylaxis for the prevention of infective endocarditis fell substantially after introduction of the NICE guidance (mean 10,900 prescriptions per month [Jan 1, 2004, to March 31, 2008] vs 2236 prescriptions per month [April 1, 2008, to March 31, 2013], pinfective endocarditis increased significantly above the projected historical trend, by 0·11 cases per 10 million people per month (95% CI 0·05-0·16, pinfective endocarditis was significant for both individuals at high risk of infective endocarditis and those at lower risk. Although our data do not establish a causal association, prescriptions

  20. Interrupting seasonal transmission of Schistosoma haematobium and control of soil-transmitted helminthiasis in northern and central Côte d'Ivoire: a SCORE study protocol.

    Science.gov (United States)

    Tian-Bi, Yves-Nathan T; Ouattara, Mamadou; Knopp, Stefanie; Coulibaly, Jean T; Hürlimann, Eveline; Webster, Bonnie; Allan, Fiona; Rollinson, David; Meïté, Aboulaye; Diakité, Nana R; Konan, Cyrille K; N'Goran, Eliézer K; Utzinger, Jürg

    2018-01-29

    To achieve a world free of schistosomiasis, the objective is to scale up control and elimination efforts in all endemic countries. Where interruption of transmission is considered feasible, countries are encouraged to implement a comprehensive intervention package, including preventive chemotherapy, information, education and communication (IEC), water, sanitation and hygiene (WASH), and snail control. In northern and central Côte d'Ivoire, transmission of Schistosoma haematobium is seasonal and elimination might be achieved. In a cluster-randomised trial, we will assess different treatment schemes to interrupt S. haematobium transmission and control soil-transmitted helminthiasis over a 3-year period. We will compare the impact of (i) arm A: annual mass drug administration (MDA) with praziquantel and albendazole before the peak schistosomiasis transmission season; (ii) arm B: annual MDA after the peak schistosomiasis transmission season; (iii) arm C: two yearly treatments before and after peak schistosomiasis transmission; and (iv) arm D: annual MDA before peak schistosomiasis transmission, coupled with chemical snail control using niclosamide. The prevalence and intensity of S. haematobium and soil-transmitted helminth infections will be assessed using urine filtration and Kato-Katz thick smears, respectively, in six administrative regions in northern and central parts of Côte d'Ivoire. Once a year, urine and stool samples will be collected and examined from 50 children aged 5-8 years, 100 children aged 9-12 years and 50 adults aged 20-55 years in each of 60 selected villages. Changes in S. haematobium and soil-transmitted helminth prevalence and intensity will be assessed between years and stratified by intervention arm. In the 15 villages randomly assigned to intervention arm D, intermediate host snails will be collected three times per year, before niclosamide is applied to the selected freshwater bodies. The snail abundance and infection rates over time

  1. The Use of Piecewise Growth Models to Estimate Learning Trajectories and RtI Instructional Effects in a Comparative Interrupted Time-Series Design

    Science.gov (United States)

    Zvoch, Keith

    2016-01-01

    Piecewise growth models (PGMs) were used to estimate and model changes in the preliteracy skill development of kindergartners in a moderately sized school district in the Pacific Northwest. PGMs were applied to interrupted time-series (ITS) data that arose within the context of a response-to-intervention (RtI) instructional framework. During the…

  2. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: An interrupted time series over a 10-year period

    NARCIS (Netherlands)

    Helder, O.K.; Brug, J.; van Goudoever, J.B.; Looman, C.W.N.; Reiss, I.K.M.; Kornelisse, R.F.

    2014-01-01

    Background Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. Methods An observational study with an interrupted

  3. The impact of "Option B" on HIV transmission from mother to child in Rwanda: An interrupted time series analysis.

    Science.gov (United States)

    Abimpaye, Monique; Kirk, Catherine M; Iyer, Hari S; Gupta, Neil; Remera, Eric; Mugwaneza, Placidie; Law, Michael R

    2018-01-01

    Nearly a quarter of a million children have acquired HIV, prompting the implementation of new protocols-Option B and B+-for treating HIV+ pregnant women. While efficacy has been demonstrated in randomized trials, there is limited real-world evidence on the impact of these changes. Using longitudinal, routinely collected data we assessed the impact of the adoption of WHO Option B in Rwanda on mother to infant transmission. We used interrupted time series analysis to evaluate the impact of Option B on mother-to-child HIV transmission in Rwanda. Our primary outcome was the proportion of HIV tests in infants with positive results at six weeks of age. We included data for 20 months before and 22 months after the 2010 policy change. Of the 15,830 HIV tests conducted during our study period, 392 tested positive. We found a significant decrease in both the level (-2.08 positive tests per 100 tests conducted, 95% CI: -2.71 to -1.45, p Option B in Rwanda contributed to an immediate decrease in the rate of HIV transmission from mother to child. This suggests other countries may benefit from adopting these WHO guidelines.

  4. The impact of public transportation strikes on use of a bicycle share program in London: interrupted time series design.

    Science.gov (United States)

    Fuller, Daniel; Sahlqvist, Shannon; Cummins, Steven; Ogilvie, David

    2012-01-01

    To investigate the immediate and sustained effects of two London Underground strikes on use of a public bicycle share program. An interrupted time series design was used to examine the impact of two 24 hour strikes on the total number of trips per day and mean trip duration per day on the London public bicycle share program. The strikes occurred on September 6th and October 4th 2010 and limited service on the London Underground. The mean total number of trips per day over the whole study period was 14,699 (SD=5390) while the mean trip duration was 18.5 minutes (SD=3.7). Significant increases in daily trip count were observed following strike 1 (3864: 95% CI 125 to 7604) and strike 2 (11,293: 95% CI 5169 to 17,416). Events that greatly constrain the primary motorised mode of transportation for a population may have unintended short-term effects on travel behaviour. These findings suggest that limiting transportation options may have the potential to increase population levels of physical activity by promoting the use of cycling. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Prevention of brachial plexus injury-12 years of shoulder dystocia training: an interrupted time-series study.

    Science.gov (United States)

    Crofts, J F; Lenguerrand, E; Bentham, G L; Tawfik, S; Claireaux, H A; Odd, D; Fox, R; Draycott, T J

    2016-01-01

    To investigate management and outcomes of incidences of shoulder dystocia in the 12 years following the introduction of an obstetric emergencies training programme. Interrupted time-series study comparing management and neonatal outcome of births complicated by shoulder dystocia over three 4-year periods: (i) Pre-training (1996-99), (ii) Early training (2001-04), and (iii) Late training (2009-12). Southmead Hospital, Bristol, UK, with approximately 6000 births per annum. Infants and their mothers who experienced shoulder dystocia. A bi-monthly multi-professional 1-day intrapartum emergencies training course, that included a 30-minute practical session on shoulder dystocia management, commenced in 2000. Neonatal morbidity (brachial plexus injury, humeral fracture, clavicular fracture, 5-minute Apgar score dystocia (resolution manoeuvres performed, traction applied, head-to-body delivery interval). Compliance with national guidance improved with continued training. At least one recognised resolution manoeuvre was used in 99.8% (561/562) of cases of shoulder dystocia in the late training period, demonstrating a continued improvement from 46.3% (150/324, P dystocia. © 2015 Royal College of Obstetricians and Gynaecologists.

  6. Impact of the zero-markup drug policy on hospitalisation expenditure in western rural China: an interrupted time series analysis.

    Science.gov (United States)

    Yang, Caijun; Shen, Qian; Cai, Wenfang; Zhu, Wenwen; Li, Zongjie; Wu, Lina; Fang, Yu

    2017-02-01

    To assess the long-term effects of the introduction of China's zero-markup drug policy on hospitalisation expenditure and hospitalisation expenditures after reimbursement. An interrupted time series was used to evaluate the impact of the zero-markup drug policy on hospitalisation expenditure and hospitalisation expenditure after reimbursement at primary health institutions in Fufeng County of Shaanxi Province, western China. Two regression models were developed. Monthly average hospitalisation expenditure and monthly average hospitalisation expenditure after reimbursement in primary health institutions were analysed covering the period 2009 through to 2013. For the monthly average hospitalisation expenditure, the increasing trend was slowed down after the introduction of the zero-markup drug policy (coefficient = -16.49, P = 0.009). For the monthly average hospitalisation expenditure after reimbursement, the increasing trend was slowed down after the introduction of the zero-markup drug policy (coefficient = -10.84, P = 0.064), and a significant decrease in the intercept was noted after the second intervention of changes in reimbursement schemes of the new rural cooperative medical insurance (coefficient = -220.64, P markup drug policy in western China. However, hospitalisation expenditure and hospitalisation expenditure after reimbursement were still increasing. More effective policies are needed to prevent these costs from continuing to rise. © 2016 John Wiley & Sons Ltd.

  7. The impact of an electronic health record on nurse sensitive patient outcomes: an interrupted time series analysis.

    Science.gov (United States)

    Dowding, Dawn W; Turley, Marianne; Garrido, Terhilda

    2012-01-01

    To evaluate the impact of electronic health record (EHR) implementation on nursing care processes and outcomes. Interrupted time series analysis, 2003-2009. A large US not-for-profit integrated health care organization. 29 hospitals in Northern and Southern California. An integrated EHR including computerized physician order entry, nursing documentation, risk assessment tools, and documentation tools. Percentage of patients with completed risk assessments for hospital acquired pressure ulcers (HAPUs) and falls (process measures) and rates of HAPU and falls (outcome measures). EHR implementation was significantly associated with an increase in documentation rates for HAPU risk (coefficient 2.21, 95% CI 0.67 to 3.75); the increase for fall risk was not statistically significant (0.36; -3.58 to 4.30). EHR implementation was associated with a 13% decrease in HAPU rates (coefficient -0.76, 95% CI -1.37 to -0.16) but no decrease in fall rates (-0.091; -0.29 to 0.11). Irrespective of EHR implementation, HAPU rates decreased significantly over time (-0.16; -0.20 to -0.13), while fall rates did not (0.0052; -0.01 to 0.02). Hospital region was a significant predictor of variation for both HAPU (0.72; 0.30 to 1.14) and fall rates (0.57; 0.41 to 0.72). The introduction of an integrated EHR was associated with a reduction in the number of HAPUs but not in patient fall rates. Other factors, such as changes over time and hospital region, were also associated with variation in outcomes. The findings suggest that EHR impact on nursing care processes and outcomes is dependent on a number of factors that should be further explored.

  8. Changing use of surgical antibiotic prophylaxis in Thika Hospital, Kenya: a quality improvement intervention with an interrupted time series design.

    Directory of Open Access Journals (Sweden)

    Alexander M Aiken

    Full Text Available In low-income countries, Surgical Site Infection (SSI is a common form of hospital-acquired infection. Antibiotic prophylaxis is an effective method of preventing these infections, if given immediately before the start of surgery. Although several studies in Africa have compared pre-operative versus post-operative prophylaxis, there are no studies describing the implementation of policies to improve prescribing of surgical antibiotic prophylaxis in African hospitals.We conducted SSI surveillance at a typical Government hospital in Kenya over a 16 month period between August 2010 and December 2011, using standard definitions of SSI and the extent of contamination of surgical wounds. As an intervention, we developed a hospital policy that advised pre-operative antibiotic prophylaxis and discouraged extended post-operative antibiotics use. We measured process, outcome and balancing effects of this intervention in using an interrupted time series design.From a starting point of near-exclusive post-operative antibiotic use, after policy introduction in February 2011 there was rapid adoption of the use of pre-operative antibiotic prophylaxis (60% of operations at 1 week; 98% at 6 weeks and a substantial decrease in the use of post-operative antibiotics (40% of operations at 1 week; 10% at 6 weeks in Clean and Clean-Contaminated surgery. There was no immediate step-change in risk of SSI, but overall, there appeared to be a moderate reduction in the risk of superficial SSI across all levels of wound contamination. There were marked reductions in the costs associated with antibiotic use, the number of intravenous injections performed and nursing time spent administering these.Implementation of a locally developed policy regarding surgical antibiotic prophylaxis is an achievable quality improvement target for hospitals in low-income countries, and can lead to substantial benefits for individual patients and the institution.

  9. Changing use of surgical antibiotic prophylaxis in Thika Hospital, Kenya: a quality improvement intervention with an interrupted time series design.

    Science.gov (United States)

    Aiken, Alexander M; Wanyoro, Anthony K; Mwangi, Jonah; Juma, Francis; Mugoya, Isaac K; Scott, J Anthony G

    2013-01-01

    In low-income countries, Surgical Site Infection (SSI) is a common form of hospital-acquired infection. Antibiotic prophylaxis is an effective method of preventing these infections, if given immediately before the start of surgery. Although several studies in Africa have compared pre-operative versus post-operative prophylaxis, there are no studies describing the implementation of policies to improve prescribing of surgical antibiotic prophylaxis in African hospitals. We conducted SSI surveillance at a typical Government hospital in Kenya over a 16 month period between August 2010 and December 2011, using standard definitions of SSI and the extent of contamination of surgical wounds. As an intervention, we developed a hospital policy that advised pre-operative antibiotic prophylaxis and discouraged extended post-operative antibiotics use. We measured process, outcome and balancing effects of this intervention in using an interrupted time series design. From a starting point of near-exclusive post-operative antibiotic use, after policy introduction in February 2011 there was rapid adoption of the use of pre-operative antibiotic prophylaxis (60% of operations at 1 week; 98% at 6 weeks) and a substantial decrease in the use of post-operative antibiotics (40% of operations at 1 week; 10% at 6 weeks) in Clean and Clean-Contaminated surgery. There was no immediate step-change in risk of SSI, but overall, there appeared to be a moderate reduction in the risk of superficial SSI across all levels of wound contamination. There were marked reductions in the costs associated with antibiotic use, the number of intravenous injections performed and nursing time spent administering these. Implementation of a locally developed policy regarding surgical antibiotic prophylaxis is an achievable quality improvement target for hospitals in low-income countries, and can lead to substantial benefits for individual patients and the institution.

  10. Evaluation of a clinical decision support tool for osteoporosis disease management: protocol for an interrupted time series design.

    Science.gov (United States)

    Kastner, Monika; Sawka, Anna; Thorpe, Kevin; Chignel, Mark; Marquez, Christine; Newton, David; Straus, Sharon E

    2011-07-22

    Osteoporosis affects over 200 million people worldwide at a high cost to healthcare systems. Although guidelines on assessing and managing osteoporosis are available, many patients are not receiving appropriate diagnostic testing or treatment. Findings from a systematic review of osteoporosis interventions, a series of mixed-methods studies, and advice from experts in osteoporosis and human-factors engineering were used collectively to develop a multicomponent tool (targeted to family physicians and patients at risk for osteoporosis) that may support clinical decision making in osteoporosis disease management at the point of care. A three-phased approach will be used to evaluate the osteoporosis tool. In phase 1, the tool will be implemented in three family practices. It will involve ensuring optimal functioning of the tool while minimizing disruption to usual practice. In phase 2, the tool will be pilot tested in a quasi-experimental interrupted time series (ITS) design to determine if it can improve osteoporosis disease management at the point of care. Phase 3 will involve conducting a qualitative postintervention follow-up study to better understand participants' experiences and perceived utility of the tool and readiness to adopt the tool at the point of care. The osteoporosis tool has the potential to make several contributions to the development and evaluation of complex, chronic disease interventions, such as the inclusion of an implementation strategy prior to conducting an evaluation study. Anticipated benefits of the tool may be to increase awareness for patients about osteoporosis and its associated risks and provide an opportunity to discuss a management plan with their physician, which may all facilitate patient self-management.

  11. Reducing waiting time and raising outpatient satisfaction in a Chinese public tertiary general hospital-an interrupted time series study

    Directory of Open Access Journals (Sweden)

    Jing Sun

    2017-08-01

    Full Text Available Abstract Background It is globally agreed that a well-designed health system deliver timely and convenient access to health services for all patients. Many interventions aiming to reduce waiting times have been implemented in Chinese public tertiary hospitals to improve patients’ satisfaction. However, few were well-documented, and the effects were rarely measured with robust methods. Methods We conducted a longitudinal study of the length of waiting times in a public tertiary hospital in Southern China which developed comprehensive data collection systems. Around an average of 60,000 outpatients and 70,000 prescribed outpatients per month were targeted for the study during Oct 2014-February 2017. We analyzed longitudinal time series data using a segmented linear regression model to assess changes in levels and trends of waiting times before and after the introduction of waiting time reduction interventions. Pearson correlation analysis was conducted to indicate the strength of association between waiting times and patient satisfactions. The statistical significance level was set at 0.05. Results The monthly average length of waiting time decreased 3.49 min (P = 0.003 for consultations and 8.70 min (P = 0.02 for filling prescriptions in the corresponding month when respective interventions were introduced. The trend shifted from baseline slight increasing to afterwards significant decreasing for filling prescriptions (P =0.003. There was a significant negative correlation between waiting time of filling prescriptions and outpatient satisfaction towards pharmacy services (r = −0.71, P = 0.004. Conclusions The interventions aimed at reducing waiting time and raising patient satisfaction in Fujian Provincial Hospital are effective. A long-lasting reduction effect on waiting time for filling prescriptions was observed because of carefully designed continuous efforts, rather than a one-time campaign, and with appropriate incentives

  12. Reducing waiting time and raising outpatient satisfaction in a Chinese public tertiary general hospital-an interrupted time series study.

    Science.gov (United States)

    Sun, Jing; Lin, Qian; Zhao, Pengyu; Zhang, Qiongyao; Xu, Kai; Chen, Huiying; Hu, Cecile Jia; Stuntz, Mark; Li, Hong; Liu, Yuanli

    2017-08-22

    It is globally agreed that a well-designed health system deliver timely and convenient access to health services for all patients. Many interventions aiming to reduce waiting times have been implemented in Chinese public tertiary hospitals to improve patients' satisfaction. However, few were well-documented, and the effects were rarely measured with robust methods. We conducted a longitudinal study of the length of waiting times in a public tertiary hospital in Southern China which developed comprehensive data collection systems. Around an average of 60,000 outpatients and 70,000 prescribed outpatients per month were targeted for the study during Oct 2014-February 2017. We analyzed longitudinal time series data using a segmented linear regression model to assess changes in levels and trends of waiting times before and after the introduction of waiting time reduction interventions. Pearson correlation analysis was conducted to indicate the strength of association between waiting times and patient satisfactions. The statistical significance level was set at 0.05. The monthly average length of waiting time decreased 3.49 min (P = 0.003) for consultations and 8.70 min (P = 0.02) for filling prescriptions in the corresponding month when respective interventions were introduced. The trend shifted from baseline slight increasing to afterwards significant decreasing for filling prescriptions (P =0.003). There was a significant negative correlation between waiting time of filling prescriptions and outpatient satisfaction towards pharmacy services (r = -0.71, P = 0.004). The interventions aimed at reducing waiting time and raising patient satisfaction in Fujian Provincial Hospital are effective. A long-lasting reduction effect on waiting time for filling prescriptions was observed because of carefully designed continuous efforts, rather than a one-time campaign, and with appropriate incentives implemented by a taskforce authorized by the hospital managers. This

  13. Breeding limits foraging time : Evidence of interrupted foraging response from body mass variation in a tropical environment

    NARCIS (Netherlands)

    Nwaogu, Chima J.; Dietz, Maurine W.; Tieleman, B. Irene; Cresswell, Will

    Birds should store body reserves if starvation risk is anticipated; this is known as an ‘interrupted foraging response’. If foraging remains unrestricted, however, body mass should remain low to limit the predation risk that gaining and carrying body reserves entails. In temperate environments mass

  14. Effects of Interruptibility-Aware Robot Behavior

    OpenAIRE

    Banerjee, Siddhartha; Silva, Andrew; Feigh, Karen; Chernova, Sonia

    2018-01-01

    As robots become increasingly prevalent in human environments, there will inevitably be times when a robot needs to interrupt a human to initiate an interaction. Our work introduces the first interruptibility-aware mobile robot system, and evaluates the effects of interruptibility-awareness on human task performance, robot task performance, and on human interpretation of the robot's social aptitude. Our results show that our robot is effective at predicting interruptibility at high accuracy, ...

  15. Randomized trial of time-limited interruptions of protease inhibitor-based antiretroviral therapy (ART vs. continuous therapy for HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Cynthia Firnhaber

    Full Text Available The clinical outcomes of short interruptions of PI-based ART regimens remains undefined.A 2-arm non-inferiority trial was conducted on 53 HIV-1 infected South African participants with viral load 450 cells/µl on stavudine (or zidovudine, lamivudine and lopinavir/ritonavir. Subjects were randomized to a sequential 2, 4 and 8-week ART interruptions or b continuous ART (cART. Primary analysis was based on the proportion of CD4 count >350 cells(c/ml over 72 weeks. Adherence, HIV-1 drug resistance, and CD4 count rise over time were analyzed as secondary endpoints.The proportions of CD4 counts >350 cells/µl were 82.12% for the intermittent arm and 93.73 for the cART arm; the difference of 11.95% was above the defined 10% threshold for non-inferiority (upper limit of 97.5% CI, 24.1%; 2-sided CI: -0.16, 23.1. No clinically significant differences in opportunistic infections, adverse events, adherence or viral resistance were noted; after randomization, long-term CD4 rise was observed only in the cART arm.We are unable to conclude that short PI-based ART interruptions are non-inferior to cART in retention of immune reconstitution; however, short interruptions did not lead to a greater rate of resistance mutations or adverse events than cART suggesting that this regimen may be more forgiving than NNRTIs if interruptions in therapy occur.ClinicalTrials.gov NCT00100646.

  16. Sound, memory and interruption

    DEFF Research Database (Denmark)

    Pinder, David

    2016-01-01

    This chapter considers how art can interrupt the times and spaces of urban development so they might be imagined, experienced and understood differently. It focuses on the construction of the M11 Link Road through north-east London during the 1990s that demolished hundreds of homes and displaced...... around a thousand people. The highway was strongly resisted and it became the site of one of the country’s longest and largest anti-road struggles. The chapter addresses specifically Graeme Miller’s sound walk LINKED (2003), which for more than a decade has been broadcasting memories and stories...... of people who were violently displaced by the road as well as those who actively sought to halt it. Attention is given to the walk’s interruption of senses of the given and inevitable in two main ways. The first is in relation to the pace of the work and its deployment of slowness and arrest in a context...

  17. Impact of statin related media coverage on use of statins: interrupted time series analysis with UK primary care data.

    Science.gov (United States)

    Matthews, Anthony; Herrett, Emily; Gasparrini, Antonio; Van Staa, Tjeerd; Goldacre, Ben; Smeeth, Liam; Bhaskaran, Krishnan

    2016-06-28

     To quantify how a period of intense media coverage of controversy over the risk:benefit balance of statins affected their use.  Interrupted time series analysis of prospectively collected electronic data from primary care.  Clinical Practice Research Datalink (CPRD) in the United Kingdom.  Patients newly eligible for or currently taking statins for primary and secondary cardiovascular disease prevention in each month in January 2011-March 2015.  Adjusted odds ratios for starting/stopping taking statins after the media coverage (October 2013-March 2014).  There was no evidence that the period of high media coverage was associated with changes in statin initiation among patients with a high recorded risk score for cardiovascular disease (primary prevention) or a recent cardiovascular event (secondary prevention) (odds ratio 0.99 (95% confidence interval 0.87 to 1.13; P=0.92) and 1.04 (0.92 to 1.18; P=0.54), respectively), though there was a decrease in the overall proportion of patients with a recorded risk score. Patients already taking statins were more likely to stop taking them for both primary and secondary prevention after the high media coverage period (1.11 (1.05 to 1.18; P<0.001) and 1.12 (1.04 to 1.21; P=0.003), respectively). Stratified analyses showed that older patients and those with a longer continuous prescription were more likely to stop taking statins after the media coverage. In post hoc analyses, the increased rates of cessation were no longer observed after six months.  A period of intense public discussion over the risks:benefit balance of statins, covered widely in the media, was followed by a transient rise in the proportion of people who stopped taking statins. This research highlights the potential for widely covered health stories in the lay media to impact on healthcare related behaviour. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Microstructural changes after control rolling and interrupted accelerated cooling simulations in pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Mourino, Nuria; Petrov, Roumen [Department of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052 Ghent (Belgium); Bae, Jin-Ho; Kim, Kisoo [Sheet Products and Process Research Group, POSCO, Jeonnam, 545-090 (Korea, Republic of); Kestens, Leo A.I. [Department of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052 Ghent (Belgium); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD, Delft (Netherlands)

    2011-04-15

    The {gamma}-{alpha} transformation and final microstructure in pipeline steel was studied by carrying out a number of physical simulations of industrial hot rolling schedules. Particularly, the effect of the reheating temperature, deformation and cooling parameters on the transformation temperatures and final grain size were considered with a goal to obtain an appropriate thermo-mechanical processing route which will generate appropriate microstructures for pipeline applications. The CCT diagram of the steel was derived experimentally by means of dilatometric tests. Hot torsion experiments were applied in a multi-deformation cycle at various temperatures in the austenite region to simulate industrial rolling schedules. By variation of the reheating temperature, equivalent strain, and accelerated cooling, different types of microstructures were obtained. It was found that the deformation increases the transformation temperatures whereas the higher cooling rates after deformation decrease them. Post-deformation microstructure consists of fine bainitic-ferrite grains with dispersed carbides and small amount of dispersed martensite/austenite islands which can be controlled by varying the reheating temperature, deformation and post-deformation cooling. The detailed microstructure characteristics obtained from the present work could be used to optimize the mechanical properties, strength and toughness of pipeline steel grades by an appropriate control of the thermo-mechanical processing. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. The impact of family policy and career interruptions on women's perceptions of negative occupational consequences of full-time home care

    DEFF Research Database (Denmark)

    Ejrnæs, Anders

    2011-01-01

    for their careers. On the one hand, our findings confirm the hypothesis that long-term absence from the labour market due to full-time care has negative consequences for women's occupational careers. On the other hand, our findings show that countries with well paid leave schemes combined with access to high...... quality childcare reduce the perceived negative occupational consequences of the time spent on full-time care. This is the case independently of the duration of the career interruption due to care-giving....

  20. Effectiveness of employer financial incentives in reducing time to report worker injury: an interrupted time series study of two Australian workers' compensation jurisdictions.

    Science.gov (United States)

    Lane, Tyler J; Gray, Shannon; Hassani-Mahmooei, Behrooz; Collie, Alex

    2018-01-05

    Early intervention following occupational injury can improve health outcomes and reduce the duration and cost of workers' compensation claims. Financial early reporting incentives (ERIs) for employers may shorten the time between injury and access to compensation benefits and services. We examined ERI effect on time spent in the claim lodgement process in two Australian states: South Australia (SA), which introduced them in January 2009, and Tasmania (TAS), which introduced them in July 2010. Using administrative records of 1.47 million claims lodged between July 2006 and June 2012, we conducted an interrupted time series study of ERI impact on monthly median days in the claim lodgement process. Time periods included claim reporting, insurer decision, and total time. The 18-month gap in implementation between the states allowed for a multiple baseline design. In SA, we analysed periods within claim reporting: worker and employer reporting times (similar data were not available in TAS). To account for external threats to validity, we examined impact in reference to a comparator of other Australian workers' compensation jurisdictions. Total time in the process did not immediately change, though trend significantly decreased in both jurisdictions (SA: -0.36 days per month, 95% CI -0.63 to -0.09; TAS: 0.35, -0.50 to -0.20). Claim reporting time also decreased in both (SA: -1.6 days, -2.4 to -0.8; TAS: -5.4, -7.4 to -3.3). In TAS, there was a significant increase in insurer decision time (4.6, 3.9 to 5.4) and a similar but non-significant pattern in SA. In SA, worker reporting time significantly decreased (-4.7, -5.8 to -3.5), but employer reporting time did not (-0.3, -0.8 to 0.2). The results suggest that ERIs reduced claim lodgement time and, in the long-term, reduced total time in the claim lodgement process. However, only worker reporting time significantly decreased in SA, indicating that ERIs may not have shortened the process through the intended target of

  1. Current interruption transients calculation

    CERN Document Server

    Peelo, David F

    2014-01-01

    Provides an original, detailed and practical description of current interruption transients, origins, and the circuits involved, and how they can be calculated Current Interruption Transients Calculationis a comprehensive resource for the understanding, calculation and analysis of the transient recovery voltages (TRVs) and related re-ignition or re-striking transients associated with fault current interruption and the switching of inductive and capacitive load currents in circuits. This book provides an original, detailed and practical description of current interruption transients, origins,

  2. Understanding Emergency Medicine Physicians Multitasking Behaviors Around Interruptions.

    Science.gov (United States)

    Fong, Allan; Ratwani, Raj M

    2018-06-11

    Interruptions can adversely impact human performance, particularly in fast-paced and high-risk environments such as the emergency department (ED). Understanding physician behaviors before, during, and after interruptions is important to the design and promotion of safe and effective workflow solutions. However, traditional human factors based interruption models do not accurately reflect the complexities of real-world environments like the ED and may not capture multiple interruptions and multitasking. We present a more comprehensive framework for understanding interruptions that is composed of three phases, each with multiple levels: Interruption Start Transition, Interruption Engagement, and Interruption End Transition. This three-phase framework is not constrained to discrete task transitions, providing a robust method to categorize multitasking behaviors around interruptions. We apply this framework in categorizing 457 interruption episodes. 457 interruption episodes were captured during 36 hours of observation. The interrupted task was immediately suspended 348 (76.1%) times. Participants engaged in new self-initiated tasks during the interrupting task 164 (35.9%) times and did not directly resume the interrupted task in 284 (62.1%) interruption episodes. Using this framework provides a more detailed description of the types of physician behaviors in complex environments. Understanding the different types of interruption and resumption patterns, which may have a different impact on performance, can support the design of interruption mitigation strategies. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. Impact of pharmaceutical policy interventions on utilization of antipsychotic medicines in Finland and Portugal in times of economic recession: interrupted time series analyses.

    Science.gov (United States)

    Leopold, Christine; Zhang, Fang; Mantel-Teeuwisse, Aukje K; Vogler, Sabine; Valkova, Silvia; Ross-Degnan, Dennis; Wagner, Anita K

    2014-07-25

    To analyze the impacts of pharmaceutical sector policies implemented to contain country spending during the economic recession--a reference price system in Finland and a mix of policies including changes in reimbursement rates, a generic promotion campaign and discounts granted to the public payer in Portugal - on utilization of, as a proxy for access to, antipsychotic medicines. We obtained monthly IMS Health sales data in standard units of antipsychotic medicines in Portugal and Finland for the period January 2007 to December 2011. We used an interrupted time series design to estimate changes in overall use and generic market shares by comparing pre-policy and post-policy levels and trends. Both countries' policy approaches were associated with slight, likely unintended, decreases in overall use of antipsychotic medicines and with increases in generic market shares of major antipsychotic products. In Finland, quetiapine and risperidone generic market shares increased substantially (estimates one year post-policy compared to before, quetiapine: 6.80% [3.92%, 9.68%]; risperidone: 11.13% [6.79%, 15.48%]. The policy interventions in Portugal resulted in a substantially increased generic market share for amisulpride (estimate one year post-policy compared to before: 22.95% [21.01%, 24.90%]; generic risperidone already dominated the market prior to the policy interventions. Different policy approaches to contain pharmaceutical expenditures in times of the economic recession in Finland and Portugal had intended--increased use of generics--and likely unintended--slightly decreased overall sales, possibly consistent with decreased access to needed medicines--impacts. These findings highlight the importance of monitoring and evaluating the effects of pharmaceutical policy interventions on use of medicines and health outcomes.

  4. The development, implementation and evaluation of clinical pathways for chronic obstructive pulmonary disease (COPD) in Saskatchewan: protocol for an interrupted times series evaluation.

    Science.gov (United States)

    Rotter, Thomas; Plishka, Christopher; Hansia, Mohammed Rashaad; Goodridge, Donna; Penz, Erika; Kinsman, Leigh; Lawal, Adegboyega; O'Quinn, Sheryl; Buchan, Nancy; Comfort, Patricia; Patel, Prakesh; Anderson, Sheila; Winkel, Tanya; Lang, Rae Lynn; Marciniuk, Darcy D

    2017-11-28

    Chronic obstructive pulmonary disease (COPD) has substantial economic and human costs; it is expected to be the third leading cause of death worldwide by 2030. To minimize these costs high quality guidelines have been developed. However, guidelines alone rarely result in meaningful change. One method of integrating guidelines into practice is the use of clinical pathways (CPWs). CPWs bring available evidence to a range of healthcare professionals by detailing the essential steps in care and adapting guidelines to the local context. We are working with local stakeholders to develop CPWs for COPD with the aims of improving care while reducing utilization. The CPWs will employ several steps including: standardizing diagnostic training, unifying components of chronic disease care, coordinating education and reconditioning programs, and ensuring care uses best practices. Further, we have worked to identify evidence-informed implementation strategies which will be tailored to the local context. We will conduct a three-year research project using an interrupted time series (ITS) design in the form of a multiple baseline approach with control groups. The CPW will be implemented in two health regions (experimental groups) and two health regions will act as controls (control groups). The experimental and control groups will each contain an urban and rural health region. Primary outcomes for the study will be quality of care operationalized using hospital readmission rates and emergency department (ED) presentation rates. Secondary outcomes will be healthcare utilization and guideline adherence, operationalized using hospital admission rates, hospital length of stay and general practitioner (GP) visits. Results will be analyzed using segmented regression analysis. Funding has been procured from multiple stakeholders. The project has been deemed exempt from ethics review as it is a quality improvement project. Intervention implementation is expected to begin in summer of 2017

  5. Did the Great Recession increase suicides in the USA? Evidence from an interrupted time-series analysis.

    Science.gov (United States)

    Harper, Sam; Bruckner, Tim A

    2017-07-01

    Research suggests that the Great Recession of 2007-2009 led to nearly 5000 excess suicides in the United States. However, prior work has not accounted for seasonal patterning and unique suicide trends by age and gender. We calculated monthly suicide rates from 1999 to 2013 for men and women aged 15 and above. Suicide rates before the Great Recession were used to predict the rate during and after the Great Recession. Death rates for each age-gender group were modeled using Poisson regression with robust variance, accounting for seasonal and nonlinear suicide trajectories. There were 56,658 suicide deaths during the Great Recession. Age- and gender-specific suicide trends before the recession demonstrated clear seasonal and nonlinear trajectories. Our models predicted 57,140 expected suicide deaths, leading to 482 fewer observed than expected suicides (95% confidence interval -2079, 943). We found little evidence to suggest that the Great Recession interrupted existing trajectories of suicide rates. Suicide rates were already increasing before the Great Recession for middle-aged men and women. Future studies estimating the impact of recessions on suicide should account for the diverse and unique suicide trajectories of different social groups. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Long term effect of reduced pack sizes of paracetamol on poisoning deaths and liver transplant activity in England and Wales: interrupted time series analyses

    Science.gov (United States)

    Bergen, Helen; Simkin, Sue; Dodd, Sue; Pocock, Phil; Bernal, William; Gunnell, David; Kapur, Navneet

    2013-01-01

    Objective To assess the long term effect of United Kingdom legislation introduced in September 1998 to restrict pack sizes of paracetamol on deaths from paracetamol poisoning and liver unit activity. Design Interrupted time series analyses to assess mean quarterly changes from October 1998 to the end of 2009 relative to projected deaths without the legislation based on pre-legislation trends. Setting Mortality (1993-2009) and liver unit activity (1995-2009) in England and Wales, using information from the Office for National Statistics and NHS Blood and Transplant, respectively. Participants Residents of England and Wales. Main outcome measures Suicide, deaths of undetermined intent, and accidental poisoning deaths involving single drug ingestion of paracetamol and paracetamol compounds in people aged 10 years and over, and liver unit registrations and transplantations for paracetamol induced hepatotoxicity. Results Compared with the pre-legislation level, following the legislation there was an estimated average reduction of 17 (95% confidence interval −25 to −9) deaths per quarter in England and Wales involving paracetamol alone (with or without alcohol) that received suicide or undetermined verdicts. This decrease represented a 43% reduction or an estimated 765 fewer deaths over the 11¼ years after the legislation. A similar effect was found when accidental poisoning deaths were included, and when a conservative method of analysis was used. This decrease was largely unaltered after controlling for a non-significant reduction in deaths involving other methods of poisoning and also suicides by all methods. There was a 61% reduction in registrations for liver transplantation for paracetamol induced hepatotoxicity (−11 (−20 to −1) registrations per quarter). But no reduction was seen in actual transplantations (−3 (−12 to 6)), nor in registrations after a conservative method of analysis was used. Conclusions UK legislation to reduce pack sizes of

  7. Algorithm Design of CPCI Backboard's Interrupts Management Based on VxWorks' Multi-Tasks

    Science.gov (United States)

    Cheng, Jingyuan; An, Qi; Yang, Junfeng

    2006-09-01

    This paper begins with a brief introduction of the embedded real-time operating system VxWorks and CompactPCI standard, then gives the programming interfaces of Peripheral Controller Interface (PCI) configuring, interrupts handling and multi-tasks programming interface under VxWorks, and then emphasis is placed on the software frameworks of CPCI interrupt management based on multi-tasks. This method is sound in design and easy to adapt, ensures that all possible interrupts are handled in time, which makes it suitable for data acquisition systems with multi-channels, a high data rate, and hard real-time high energy physics.

  8. Servicing a globally broadcast interrupt signal in a multi-threaded computer

    Science.gov (United States)

    Attinella, John E.; Davis, Kristan D.; Musselman, Roy G.; Satterfield, David L.

    2015-12-29

    Methods, apparatuses, and computer program products for servicing a globally broadcast interrupt signal in a multi-threaded computer comprising a plurality of processor threads. Embodiments include an interrupt controller indicating in a plurality of local interrupt status locations that a globally broadcast interrupt signal has been received by the interrupt controller. Embodiments also include a thread determining that a local interrupt status location corresponding to the thread indicates that the globally broadcast interrupt signal has been received by the interrupt controller. Embodiments also include the thread processing one or more entries in a global interrupt status bit queue based on whether global interrupt status bits associated with the globally broadcast interrupt signal are locked. Each entry in the global interrupt status bit queue corresponds to a queued global interrupt.

  9. Static Checking of Interrupt-driven Software

    DEFF Research Database (Denmark)

    Brylow, Dennis; Damgaard, Niels; Palsberg, Jens

    2001-01-01

    at the assembly level. In this paper we present the design and implementation of a static checker for interrupt-driven Z86-based software with hard real-time requirements. For six commercial microcontrollers, our checker has produced upper bounds on interrupt latencies and stack sizes, as well as verified...

  10. Basic interrupt and command structures and applications

    International Nuclear Information System (INIS)

    Davies, R.C.

    1974-01-01

    Interrupt and command structures of a real-time system are described through specific examples. References to applications of a real-time system and programing development references are supplied. (auth)

  11. Total and cause-specific mortality before and after the onset of the Greek economic crisis: an interrupted time-series analysis.

    Science.gov (United States)

    Laliotis, Ioannis; Ioannidis, John P A; Stavropoulou, Charitini

    2016-12-01

    Greece was one of the countries hit the hardest by the 2008 financial crisis in Europe. Yet, evidence on the effect of the crisis on total and cause-specific mortality remains unclear. We explored whether the economic crisis affected the trend of overall and cause-specific mortality rates. We used regional panel data from the Hellenic Statistical Authority to assess mortality trends by age, sex, region, and cause in Greece between January, 2001, and December, 2013. We used Eurostat data to calculate monthly age-standardised mortality rates per 100 000 inhabitants for each region. Data were divided into two subperiods: before the crisis (January, 2001, to August, 2008) and after the onset of the crisis (September, 2008, to December, 2013). We tested for changes in the slope of mortality by doing an interrupted time-series analysis. Overall mortality continued to decline after the onset of the financial crisis (-0·065, 95% CI -0·080 to -0·049), but at a slower pace than before the crisis (-0·13, -0·15 to -0·10; trend difference 0·062, 95% CI 0·041 to 0·083; pperiod after the onset of the crisis with extrapolated values based on the period before the crisis, we estimate that an extra 242 deaths per month occurred after the onset of the crisis. Mortality trends have been interrupted after the onset of compared with before the crisis, but changes vary by age, sex, and cause of death. The increase in deaths due to adverse events during medical treatment might reflect the effects of deterioration in quality of care during economic recessions. None. Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

  12. A prospective interrupted time series study of interventions to improve the quality, rating, framing and structure of goal-setting in community-based brain injury rehabilitation.

    Science.gov (United States)

    Hassett, Leanne; Simpson, Grahame; Cotter, Rachel; Whiting, Diane; Hodgkinson, Adeline; Martin, Diane

    2015-04-01

    To investigate whether the introduction of an electronic goals system followed by staff training improved the quality, rating, framing and structure of goals written by a community-based brain injury rehabilitation team. Interrupted time series design. Two interventions were introduced six months apart. The first intervention comprised the introduction of an electronic goals system. The second intervention comprised a staff goal training workshop. An audit protocol was devised to evaluate the goals. A random selection of goal statements from the 12 months prior to the interventions (Time 1 baseline) were compared with all goal statements written after the introduction of the electronic goals system (Time 2) and staff training (Time 3). All goals were de-identified for client and time-period, and randomly ordered. A total of 745 goals (Time 1 n = 242; Time 2 n = 283; Time 3 n = 220) were evaluated. Compared with baseline, the introduction of the electronic goals system alone significantly increased goal rating, framing and structure (χ(2) tests 144.7, 18.9, 48.1, respectively, p goal quality, which was only a trend at Time 2, was statistically significant at Time 3 (χ(2) 15.0, p ≤ 001). The training also led to a further significant increase in the framing and structuring of goals over the electronic goals system (χ(2) 11.5, 12.5, respectively, p ≤ 0.001). An electronic goals system combined with staff training improved the quality, rating, framing and structure of goal statements. © The Author(s) 2014.

  13. Post-treatment HIV-1 controllers with a long-term virological remission after the interruption of early initiated antiretroviral therapy ANRS VISCONTI Study.

    Directory of Open Access Journals (Sweden)

    Asier Sáez-Cirión

    2013-03-01

    Full Text Available Combination antiretroviral therapy (cART reduces HIV-associated morbidities and mortalities but cannot cure the infection. Given the difficulty of eradicating HIV-1, a functional cure for HIV-infected patients appears to be a more reachable short-term goal. We identified 14 HIV patients (post-treatment controllers [PTCs] whose viremia remained controlled for several years after the interruption of prolonged cART initiated during the primary infection. Most PTCs lacked the protective HLA B alleles that are overrepresented in spontaneous HIV controllers (HICs; instead, they carried risk-associated HLA alleles that were largely absent among the HICs. Accordingly, the PTCs had poorer CD8+ T cell responses and more severe primary infections than the HICs did. Moreover, the incidence of viral control after the interruption of early antiretroviral therapy was higher among the PTCs than has been reported for spontaneous control. Off therapy, the PTCs were able to maintain and, in some cases, further reduce an extremely low viral reservoir. We found that long-lived HIV-infected CD4+ T cells contributed poorly to the total resting HIV reservoir in the PTCs because of a low rate of infection of naïve T cells and a skewed distribution of resting memory CD4+ T cell subsets. Our results show that early and prolonged cART may allow some individuals with a rather unfavorable background to achieve long-term infection control and may have important implications in the search for a functional HIV cure.

  14. Reactor pressure elevation preventing device upon interruption of load

    International Nuclear Information System (INIS)

    Ota, Yasuo; Okukawa, Ryutaro.

    1996-01-01

    In a power load imbalance circuit of a steam turbine control device, a power load imbalance occurrence signal is outputted for a predetermined period of time upon occurrence of load interruption. A function for suppressing increase of number of rotation of a turbine due to load interruption is not disturbed, and the power load imbalance circuit is not operated at least after a primary peak where the number of rotation of the turbine is increased. Since a steam control valve flow rate demand signal and a turbine bypass valve flow rate demand signals are corporated subsequently to control the opening degree of the steam control valve and the turbine bypass valve, elevation of reactor pressure is always suppressed and maintained constant, as well as abrupt opening of the steam control valve due to cancel of the power load imbalance circuit when steam control valve opening demand is outputted can be prevented. (N.H.)

  15. Energy expenditure of interruptions to sedentary behavior

    Directory of Open Access Journals (Sweden)

    Strath Scott J

    2011-06-01

    Full Text Available Abstract Background Advances in technology, social influences and environmental attributes have resulted in substan-tial portions of the day spent in sedentary pursuits. Sedentary behavior may be a cause of many chronic diseases including obesity, insulin resistance, type 2 diabetes and the metabolic syndrome. Research demonstrated that breaking up sedentary time was beneficially associated with markers of body composition, cardiovascular health and type 2 diabetes. Therefore, the purpose of this study was to quantify the total energy expenditure of three different durations of physical activity within a 30-minute sedentary period and to examine the potential benefits of interrupting sedentary behavior with physical activity for weight control. Methods Participants completed four consecutive 30-minute bouts of sedentary behavior (reading, working on the computer, or doing other desk activities with and without interruptions of walking at a self-selected pace. Bout one contained no walking interruptions. Bout two contained a 1-minute walking period. Bout three contained a 2-minute walking period. Bout four contained a 5-minute walking period. Body composition and resting metabolic rate were assessed. Result Twenty males and females (18-39 years completed this study. Results of the repeated measures analysis of variance with post-hoc testing showed that significantly more energy was expended during each 30 minute sedentary bout with a walking break than in the 30 minute sedentary bout (p Conclusions This study demonstrated that making small changes, such as taking a five minute walking break every hour could yield beneficial weight control or weight loss results. Therefore, taking breaks from sedentary time is a potential outlet to prevent obesity and the rise of obesity in developed countries.

  16. Nested Interrupt Analysis of Low Cost and High Performance Embedded Systems Using GSPN Framework

    Science.gov (United States)

    Lin, Cheng-Min

    Interrupt service routines are a key technology for embedded systems. In this paper, we introduce the standard approach for using Generalized Stochastic Petri Nets (GSPNs) as a high-level model for generating CTMC Continuous-Time Markov Chains (CTMCs) and then use Markov Reward Models (MRMs) to compute the performance for embedded systems. This framework is employed to analyze two embedded controllers with low cost and high performance, ARM7 and Cortex-M3. Cortex-M3 is designed with a tail-chaining mechanism to improve the performance of ARM7 when a nested interrupt occurs on an embedded controller. The Platform Independent Petri net Editor 2 (PIPE2) tool is used to model and evaluate the controllers in terms of power consumption and interrupt overhead performance. Using numerical results, in spite of the power consumption or interrupt overhead, Cortex-M3 performs better than ARM7.

  17. Causes of unplanned interruption of radiotherapy

    International Nuclear Information System (INIS)

    Diegues, Sylvia Suelotto; Ciconelli, Rozana Mesquita; Segreto, Roberto Araujo

    2008-01-01

    Objective: To evaluate the occurrence and causes of unplanned interruption of radiotherapy. Materials and methods: Retrospective study developed in the Division of Radiotherapy of Hospital Alemao Oswaldo Cruz in Sao Paulo, SP, Brazil, with data collected from 560 dossiers of patients submitted to radiotherapy in the period between January 1, 2005 and December 31, 2005. Chi-squared and Student t tests were utilized in the data analysis, and p < 0.05 was considered as statistically significant. Results: Interruption of treatment was identified in 350 cases, corresponding to 62.5% of the patients. The reasons for treatment interruption were the following: preventive device maintenance (55%), patient's own private reasons (13%), adverse reactions to the treatment or to combined radiotherapy/chemotherapy (6%), clinical worsening (3%), two or more combined reasons (23%). The interruption time interval ranged between 1 and 24 days (mean 1.4 day). One-day interruption was mostly due to preventive device maintenance (84.4%); two-five-day interruption was due to combined reasons (48.28%). Conclusion: The most frequent cause of interruption was preventive device maintenance, with maximum two-day time interval. (author)

  18. Incidence of hip and knee replacement in patients with rheumatoid arthritis following the introduction of biological DMARDs: an interrupted time-series analysis using nationwide Danish healthcare registers.

    Science.gov (United States)

    Cordtz, René Lindholm; Hawley, Samuel; Prieto-Alhambra, Daniel; Højgaard, Pil; Zobbe, Kristian; Overgaard, Søren; Odgaard, Anders; Kristensen, Lars Erik; Dreyer, Lene

    2018-05-01

    To study the impact of the introduction of biological disease-modifying anti-rheumatic drugs (bDMARDs) and associated rheumatoid arthritis (RA) management guidelines on the incidence of total hip (THR) and knee replacements (TKR) in Denmark. Nationwide register-based cohort and interrupted time-series analysis. Patients with incident RA between 1996 and 2011 were identified in the Danish National Patient Register. Patients with RA were matched on age, sex and municipality with up to 10 general population comparators (GPCs). Standardised 5-year incidence rates of THR and TKR per 1000 person-years were calculated for patients with RA and GPCs in 6-month periods. Levels and trends in the pre-bDMARD (1996-2001) were compared with the bDMARD era (2003-2016) using segmented linear regression interrupted by a 1-year lag period (2002). We identified 30 404 patients with incident RA and 297 916 GPCs. In 1996, the incidence rate of THR and TKR was 8.72 and 5.87, respectively, among patients with RA, and 2.89 and 0.42 in GPCs. From 1996 to 2016, the incidence rate of THR decreased among patients with RA, but increased among GPCs. Among patients with RA, the incidence rate of TKR increased from 1996 to 2001, but started to decrease from 2003 and throughout the bDMARD era. The incidence of TKR increased among GPCs from 1996 to 2016. We report that the incidence rate of THR and TKR was 3-fold and 14-fold higher, respectively among patients with RA compared with GPCs in 1996. In patients with RA, introduction of bDMARDs was associated with a decreasing incidence rate of TKR, whereas the incidence of THR had started to decrease before bDMARD introduction. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  19. Prediction of Unmet Primary Care Needs for the Medically Vulnerable Post-Disaster: An Interrupted Time-Series Analysis of Health System Responses

    Directory of Open Access Journals (Sweden)

    Amy B. Martin

    2012-09-01

    Full Text Available Disasters serve as shocks and precipitate unanticipated disturbances to the health care system. Public health surveillance is generally focused on monitoring latent health and environmental exposure effects, rather than health system performance in response to these local shocks. The following intervention study sought to determine the long-term effects of the 2005 chlorine spill in Graniteville, South Carolina on primary care access for vulnerable populations. We used an interrupted time-series approach to model monthly visits for Ambulatory Care Sensitive Conditions, an indicator of unmet primary care need, to quantify the impact of the disaster on unmet primary care need in Medicaid beneficiaries. The results showed Medicaid beneficiaries in the directly impacted service area experienced improved access to primary care in the 24 months post-disaster. We provide evidence that a health system serving the medically underserved can prove resilient and display improved adaptive capacity under adverse circumstances (i.e., technological disasters to ensure access to primary care for vulnerable sub-groups. The results suggests a new application for ambulatory care sensitive conditions as a population-based metric to advance anecdotal evidence of secondary surge and evaluate pre- and post-health system surge capacity following a disaster.

  20. Void Shapes Controlled by Using Interruption-Free Epitaxial Lateral Overgrowth of GaN Films on Patterned SiO2 AlN/Sapphire Template

    Directory of Open Access Journals (Sweden)

    Yu-An Chen

    2014-01-01

    Full Text Available GaN epitaxial layers with embedded air voids grown on patterned SiO2 AlN/sapphire templates were proposed. Using interruption-free epitaxial lateral overgrowth technology, we realized uninterrupted growth and controlled the shape of embedded air voids. These layers showed improved crystal quality using X-ray diffraction and measurement of etching pits density. Compared with conventional undoped-GaN film, the full width at half-maximum of the GaN (0 0 2 and (1 0 2 peaks decreased from 485 arcsec to 376 arcsec and from 600 arcsec to 322 arcsec, respectively. Transmission electron microscopy results showed that the coalesced GaN growth led to bending threading dislocation. We also proposed a growth model based on results of scanning electron microscopy.

  1. Contrasting Effects of Dual-task Paradigm and of Timing Interruption Paradigm in Interval Timing of the Context of Culti-modal Processing%跨通道情境下双任务范式与计时中断范式中的效应比较*

    Institute of Scientific and Technical Information of China (English)

    尹华站; 李丹; 袁祥勇; 黄希庭

    2013-01-01

    solution as it uses a blank interruption instead. The researchers consistently found a similar position and interruption effect in both paradigms (Casini & Macar, 1997; Cortin, & Remblai,, 2006; Remblai, & Cortin,, 2003). Furthermore, the results showed both the discontinuity and interference of current information processing were belong to interruption effect, but to varying extents (Cortin, & Masse, 2000; Macar, 2002). However, though the position and interruption effect were similar in the two paradigms, they have not been explored in a same stimuli series. As we know, information exchange with the outside world is not dependent on single sensory channel, but rather the interaction of cross-modal information processing. It would be valuable to explore the position and interruption effect in the context ofcross-modal processing. It would not only help to uncover the cognitive mechanism of time processing, but also have important practical values as it is more similar with daily life. Therefore, the present study was designed to investigate the position and interruption effect in the two paradigms in the cross-modal conditions. To this end, the study consisted of two experiments. In experiment 1, 2500 ms and 4500 ms were set for the target time intervals, using the same stimulus sequence (visual presentation, with aural interruption), participants were allocated to control, break and interference condition respectively. In experiment 2,the target intervals were set to 1500 ms and 2500 ms. Results of experiment 1 showed that the interruption effect is more significant in break condition regardless of target time intervals. Furthermore, under the 2500ms, position effect were found in all three conditions, whereas under the 4500ms condition, the position effect only existed in the break condition. Experiment 2 found that there was position effect consistently, regardless of the interpolation conditions or target time intervals. Besides, the interrupt effect was more

  2. On randomly interrupted diffusion

    International Nuclear Information System (INIS)

    Luczka, J.

    1993-01-01

    Processes driven by randomly interrupted Gaussian white noise are considered. An evolution equation for single-event probability distributions in presented. Stationary states are considered as a solution of a second-order ordinary differential equation with two imposed conditions. A linear model is analyzed and its stationary distributions are explicitly given. (author). 10 refs

  3. Programming a real-time operating system for satellite control applications Satellite Control Applications

    International Nuclear Information System (INIS)

    Omer, M.; Anjum, O.; Suddle, M.R.

    2004-01-01

    With the realization of ideas like formation flights and multi-body space vehicles the demands on an attitude control system have become increasingly complex. Even in its most simplified form, the control system for a typical geostationary satellite has to run various supervisory functions along with determination and control algorithms side by side. Within each algorithm it has to employ multiple actuation and sensing mechanisms and service real time interrupts, for example, in the case of actuator saturation and sensor data fusion. This entails the idea of thread scheduling and program synchronization, tasks specifically meant for a real time OS. This paper explores the embedding of attitude determination and control loop within the framework of a real time operating system provided for TI's DSP C6xxx series. The paper details out the much functionality provided within the scaleable real time kernel and the analysis and configuration tools available, It goes on to describe a layered implementation stack associated with a typical control for Geo Stationary satellites. An application for control is then presented in which state of the art analysis tools are employed to view program threads, synchronization semaphores, hardware interrupts and data exchange pipes operating in real time. (author)

  4. Effect of editors' implementation of CONSORT guidelines on the reporting of abstracts in high impact medical journals: interrupted time series analysis.

    Science.gov (United States)

    Hopewell, Sally; Ravaud, Philippe; Baron, Gabriel; Boutron, Isabelle

    2012-06-22

    To investigate the effect of the CONSORT for Abstracts guidelines, and different editorial policies used by five leading general medical journals to implement the guidelines, on the reporting quality of abstracts of randomised trials. Interrupted time series analysis. We randomly selected up to 60 primary reports of randomised trials per journal per year from five high impact, general medical journals in 2006-09, if indexed in PubMed with an electronic abstract. We excluded reports that did not include an electronic abstract, and any secondary trial publications or economic analyses. We classified journals in three categories: those not mentioning the guidelines in their instructions to authors (JAMA and New England Journal of Medicine), those referring to the guidelines in their instructions to authors but with no specific policy to implement them (BMJ), and those referring to the guidelines in their instructions to authors with an active policy to implement them (Annals of Internal Medicine and Lancet). Two authors extracted data independently using the CONSORT for Abstracts checklist. Mean number of CONSORT items reported in selected abstracts, among nine items reported in fewer than 50% of the abstracts published across the five journals in 2006. We assessed 955 reports of abstracts of randomised trials. Journals with an active policy to enforce the guidelines showed an immediate increase in the level of mean number of items reported (increase of 1.50 items; P=0.0037). At 23 months after publication of the guidelines, the mean number of items reported per abstract for the primary outcome was 5.41 of nine items, a 53% increase compared with the expected level estimated on the basis of pre-intervention trends. The change in level or trend did not increase in journals with no policy to enforce the guidelines (BMJ, JAMA, and New England Journal of Medicine). Active implementation of the CONSORT for Abstracts guidelines by journals can lead to improvements in the

  5. Do restrictive omnibus immigration laws reduce enrollment in public health insurance by Latino citizen children? A comparative interrupted time series study.

    Science.gov (United States)

    Allen, Chenoa D; McNeely, Clea A

    2017-10-01

    In the United States, there is concern that recent state laws restricting undocumented immigrants' rights could threaten access to Medicaid and the Children's Health Insurance Program (CHIP) for citizen children of immigrant parents. Of particular concern are omnibus immigration laws, state laws that include multiple provisions increasing immigration enforcement and restricting rights for undocumented immigrants. These laws could limit Medicaid/CHIP access for citizen children in immigrant families by creating misinformation about their eligibility and fostering fear and mistrust of government among immigrant parents. This study uses nationally-representative data from the National Health Interview Survey (2005-2014; n = 70,187) and comparative interrupted time series methods to assess whether passage of state omnibus immigration laws reduced access to Medicaid/CHIP for US citizen Latino children. We found that law passage did not reduce enrollment for children with noncitizen parents and actually resulted in temporary increases in coverage among Latino children with at least one citizen parent. These findings are surprising in light of prior research. We offer potential explanations for this finding and conclude with a call for future research to be expanded in three ways: 1) examine whether policy effects vary for children of undocumented parents, compared to children whose noncitizen parents are legally present; 2) examine the joint effects of immigration-related policies at different levels, from the city or county to the state to the federal; and 3) draw on the large social movements and political mobilization literature that describes when and how Latinos and immigrants push back against restrictive immigration laws. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Rotavirus vaccine impact and socioeconomic deprivation: an interrupted time-series analysis of gastrointestinal disease outcomes across primary and secondary care in the UK.

    Science.gov (United States)

    Hungerford, Daniel; Vivancos, Roberto; Read, Jonathan M; Iturriza-Gόmara, Miren; French, Neil; Cunliffe, Nigel A

    2018-01-29

    Rotavirus causes severe gastroenteritis in infants and young children worldwide. The UK introduced the monovalent rotavirus vaccine (Rotarix®) in July 2013. Vaccination is free of charge to parents, with two doses delivered at 8 and 12 weeks of age. We evaluated vaccine impact across a health system in relation to socioeconomic deprivation. We used interrupted time-series analyses to assess changes in monthly health-care attendances in Merseyside, UK, for all ages, from July 2013 to June 2016, compared to predicted counterfactual attendances without vaccination spanning 3-11 years pre-vaccine. Outcome measures included laboratory-confirmed rotavirus gastroenteritis (RVGE) hospitalisations, acute gastroenteritis (AGE) hospitalisations, emergency department (ED) attendances for gastrointestinal conditions and consultations for infectious gastroenteritis at community walk-in centres (WIC) and general practices (GP). All analyses were stratified by age. Hospitalisations were additionally stratified by vaccine uptake and small-area-level socioeconomic deprivation. The uptake of the first and second doses of rotavirus vaccine was 91.4% (29,108/31,836) and 86.7% (27,594/31,836), respectively. Among children aged impact was greatest during the rotavirus season and for vaccine-eligible age groups. In adults aged 65+ years, AGE hospitalisations fell by 25% (95% CI 19-30%; p socioeconomically deprived communities (adjusted incident rate ratio 1.57; 95% CI 1.51-1.64; p impact was greatest among the most deprived populations, despite lower vaccine uptake. Prioritising vaccine uptake in socioeconomically deprived communities should give the greatest health benefit in terms of population disease burden.

  7. 33-GVA interrupter test facility

    International Nuclear Information System (INIS)

    Parsons, W.M.; Honig, E.M.; Warren, R.W.

    1979-01-01

    The use of commercial ac circuit breakers for dc switching operations requires that they be evaluated to determine their dc limitations. Two 2.4-GVA facilities have been constructed and used for this purpose at LASL during the last several years. In response to the increased demand on switching technology, a 33-GVA facility has been constructed. Novel features incorporated into this facility include (1) separate capacitive and cryogenic inductive energy storage systems, (2) fiber-optic controls and optically-coupled data links, and (3) digital data acquisition systems. Facility details and planned tests on an experimental rod-array vacuum interrupter are presented

  8. Interruption Practice Reduces Errors

    Science.gov (United States)

    2014-01-01

    miscalculations (Koppel et al., 2005). There are cases where the user (medical staff, MD, Nurse , etc.) forgets to complete the PCS which is to log off or...13. SUPPLEMENTARY NOTES Proceedings of the Human Factors and Ergonomics Society Annual Meeting, vol. 58, 1 vol. pp. 265-269, 2014. 14. ABSTRACT...2000). The effects of interruptions in work activ- ity: Field and laboratory results. Applied Ergonomics , 31(5), 537– 543. González, V. M., & Mark, G

  9. Treatment interruptions: Statistics, causes and management in service radiotherapy

    International Nuclear Information System (INIS)

    Ferrando Sanchez, A.; Milanes Gaillet, A. I.; Eugui Martinez, R.; Crespo Diaz, M. P.

    2013-01-01

    Despite the clinical maximum administer the prescribed dose at a given time, treatment interruptions are unavoidable in practice. In tumors quickly reproduce no evidence that the prolongation thereof entails loss of tumor control. It has tracked two of these conditions: squamous cell cancer of the head and neck (SCCHN) and lung cancer (NSCLC) over 2011 and 2012 to evaluate both the number of stops treatment as the reason for them and its management. (Author)

  10. Improving Neuromuscular Monitoring and Reducing Residual Neuromuscular Blockade With E-Learning: Protocol for the Multicenter Interrupted Time Series INVERT Study.

    Science.gov (United States)

    Thomsen, Jakob Louis Demant; Mathiesen, Ole; Hägi-Pedersen, Daniel; Skovgaard, Lene Theil; Østergaard, Doris; Engbaek, Jens; Gätke, Mona Ring

    2017-10-06

    Muscle relaxants facilitate endotracheal intubation under general anesthesia and improve surgical conditions. Residual neuromuscular blockade occurs when the patient is still partially paralyzed when awakened after surgery. The condition is associated with subjective discomfort and an increased risk of respiratory complications. Use of an objective neuromuscular monitoring device may prevent residual block. Despite this, many anesthetists refrain from using the device. Efforts to increase the use of objective monitoring are time consuming and require the presence of expert personnel. A neuromuscular monitoring e-learning module might support consistent use of neuromuscular monitoring devices. The aim of the study is to assess the effect of a neuromuscular monitoring e-learning module on anesthesia staff's use of objective neuromuscular monitoring and the incidence of residual neuromuscular blockade in surgical patients at 6 Danish teaching hospitals. In this interrupted time series study, we are collecting data repeatedly, in consecutive 3-week periods, before and after the intervention, and we will analyze the effect using segmented regression analysis. Anesthesia departments in the Zealand Region of Denmark are included, and data from all patients receiving a muscle relaxant are collected from the anesthesia information management system MetaVision. We will assess the effect of the module on all levels of potential effect: staff's knowledge and skills, patient care practice, and patient outcomes. The primary outcome is use of neuromuscular monitoring in patients according to the type of muscle relaxant received. Secondary outcomes include last recorded train-of-four value, administration of reversal agents, and time to discharge from the postanesthesia care unit as well as a multiple-choice test to assess knowledge. The e-learning module was developed based on a needs assessment process, including focus group interviews, surveys, and expert opinions. The e

  11. The effects of financial incentives for case finding for depression in patients with diabetes and coronary heart disease: interrupted time series analysis.

    Science.gov (United States)

    McLintock, Kate; Russell, Amy M; Alderson, Sarah L; West, Robert; House, Allan; Westerman, Karen; Foy, Robbie

    2014-08-20

    To evaluate the effects of Quality and Outcomes Framework (QOF) incentivised case finding for depression on diagnosis and treatment in targeted and non-targeted long-term conditions. Interrupted time series analysis. General practices in Leeds, UK. 65 (58%) of 112 general practices shared data on 37,229 patients with diabetes and coronary heart disease targeted by case finding incentives, and 101,008 patients with four other long-term conditions not targeted (hypertension, epilepsy, chronic obstructive pulmonary disease and asthma). Incentivised case finding for depression using two standard screening questions. Clinical codes indicating new depression-related diagnoses and new prescriptions of antidepressants. We extracted routinely recorded data from February 2002 through April 2012. The number of new diagnoses and prescriptions for those on registers was modelled with a binomial regression, which provided the strength of associations between time periods and their rates. New diagnoses of depression increased from 21 to 94/100,000 per month in targeted patients between the periods 2002-2004 and 2007-2011 (OR 2.09; 1.92 to 2.27). The rate increased from 27 to 77/100,000 per month in non-targeted patients (OR 1.53; 1.46 to 1.62). The slopes in prescribing for both groups flattened to zero immediately after QOF was introduced but before incentivised case finding (p<0.01 for both). Antidepressant prescribing in targeted patients returned to the pre-QOF secular upward trend (Wald test for equivalence of slope, z=0.73, p=0.47); the slope was less steep for non-targeted patients (z=-4.14, p<0.01). Incentivised case finding increased new depression-related diagnoses. The establishment of QOF disrupted rising trends in new prescriptions of antidepressants, which resumed following the introduction of incentivised case finding. Prescribing trends are of concern given that they may include people with mild-to-moderate depression unlikely to respond to such treatment

  12. Health Facility Utilisation Changes during the Introduction of Community Case Management of Malaria in South Western Uganda: An Interrupted Time Series Approach.

    Directory of Open Access Journals (Sweden)

    Sham Lal

    Full Text Available Malaria endemic countries have scaled-up community health worker (CHW interventions, to diagnose and treat malaria in communities with limited access to public health systems. The evaluations of these programmes have centred on CHW's compliance to guidelines, but the broader changes at public health centres including utilisation and diagnoses made, has received limited attention.This analysis was conducted during a CHW-intervention for malaria in Rukungiri District, Western Uganda. Outpatient department (OPD visit data were collected for children under-5 attending three health centres one year before the CHW-intervention started (pre-intervention period and for 20 months during the intervention (intervention-period. An interrupted time series analysis with segmented regression models was used to compare the trends in malaria, non-malaria and overall OPD visits during the pre-intervention and intervention-period.The introduction of a CHW-intervention suggested the frequency of diagnoses of diarrhoeal diseases, pneumonia and helminths increased, whilst the frequency of malaria diagnoses declined at health centres. In May 2010 when the intervention began, overall health centre utilisation decreased by 63% compared to the pre-intervention period and the health centres saw 32 fewer overall visits per month compared to the pre-intervention period (p<0.001. Malaria visits also declined shortly after the intervention began and there were 27 fewer visits per month during the intervention-period compared with the pre-intervention period (p<0.05. The declines in overall and malaria visits were sustained for the entire intervention-period. In contrast, there were no observable changes in trends of non-malarial visits between the pre-intervention and intervention-period.This analysis suggests introducing a CHW-intervention can reduce the number of child malaria visits and change the profile of cases presenting at health centres. The reduction in workload of

  13. Chemoradiotherapy in patients with anal cancer: Impact of length of unplanned treatment interruption on outcome

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Andreas; Meier Zu Eissen, Juergen; Karstens, Johann H.; Bremer, Michael [Medical School Hannover (Germany). Dept. of Radiation Oncology

    2006-09-15

    The aim of this retrospective analysis was to evaluate feasibility and effectiveness of definitive chemoradiotherapy without split-course technique in anal cancer patients. From 1993 to 2003, 81 patients were treated; 13 were excluded due to various chemotherapeutic regimes, thus 68 patients were analysed. In case of acute grade 3 toxicities, treatment was halted until improvement or resolution independent of dose. Short interruption was defined as completing treatment without exceeding eight cumulative treatment days beyond scheduled plan, other patients were considered to have had prolonged interruption. Median follow-up was 46 months. Median overall treatment time was 53 days corresponding to an interruption of eight cumulative treatment days. Thirty-five patients (51%) had treatment interruption of <8 days. No acute grade 4 toxicities were observed; one fatality occurred during treatment due to ileus-like symptoms according to acute grade 5 toxicity. Comparing patients with short vs. prolonged interruption 5-year actuarial rates for local control were 85% vs. 81% (p{approx}0.605) and for colostomy-free survival 85% vs. 87% (p{approx}0.762), respectively. Chemoradiotherapy with short individualised treatment interruptions seems to be feasible with acceptable acute or late toxicities. Treatment is highly effective in terms of local control and colostomy-free survival.

  14. Impact of clinical trial findings on Bell's palsy management in general practice in the UK 2001–2012: interrupted time series regression analysis

    Science.gov (United States)

    Morales, Daniel R; Donnan, Peter T; Daly, Fergus; Staa, Tjeerd Van; Sullivan, Frank M

    2013-01-01

    Objectives To measure the incidence of Bell's palsy and determine the impact of clinical trial findings on Bell's palsy management in the UK. Design Interrupted time series regression analysis and incidence measures. Setting General practices in the UK contributing to the Clinical Practice Research Datalink (CPRD). Participants Patients ≥16 years with a diagnosis of Bell's palsy between 2001 and 2012. Interventions (1) Publication of the 2004 Cochrane reviews of clinical trials on corticosteroids and antivirals for Bell's palsy, which made no clear recommendation on their use and (2) publication of the 2007 Scottish Bell's Palsy Study (SBPS), which made a clear recommendation that treatment with prednisolone alone improves chances for complete recovery. Main outcome measures Incidence of Bell's palsy per 100 000 person-years. Changes in the management of Bell's palsy with either prednisolone therapy, antiviral therapy, combination therapy (prednisolone with antiviral therapy) or untreated cases. Results During the 12-year period, 14 460 cases of Bell's palsy were identified with an overall incidence of 37.7/100 000 person-years. The 2004 Cochrane reviews were associated with immediate falls in prednisolone therapy (−6.3% (−11.0 to −1.6)), rising trends in combination therapy (1.1% per quarter (0.5 to 1.7)) and falling trends for untreated cases (−0.8% per quarter (−1.4 to −0.3)). SBPS was associated with immediate increases in prednisolone therapy (5.1% (0.9 to 9.3)) and rising trends in prednisolone therapy (0.7% per quarter (0.4 to 1.2)); falling trends in combination therapy (−1.7% per quarter (−2.2 to −1.3)); and rising trends for untreated cases (1.2% per quarter (0.8 to 1.6)). Despite improvements, 44% still remain untreated. Conclusions SBPS was clearly associated with change in management, but a significant proportion of patients failed to receive effective treatment, which cannot be fully explained. Clarity and uncertainty in

  15. A simplified prevention bundle with dual hand hygiene audit reduces early-onset ventilator-associated pneumonia in cardiovascular surgery units: An interrupted time-series analysis.

    Directory of Open Access Journals (Sweden)

    Kang-Cheng Su

    Full Text Available To investigate the effect of a simplified prevention bundle with alcohol-based, dual hand hygiene (HH audit on the incidence of early-onset ventilation-associated pneumonia (VAP.This 3-year, quasi-experimental study with interrupted time-series analysis was conducted in two cardiovascular surgery intensive care units in a medical center. Unaware external HH audit (eHH performed by non-unit-based observers was a routine task before and after bundle implementation. Based on the realistic ICU settings, we implemented a 3-component bundle, which included: a compulsory education program, a knowing internal HH audit (iHH performed by unit-based observers, and a standardized oral care (OC protocol with 0.1% chlorhexidine gluconate. The study periods comprised 4 phases: 12-month pre-implementation phase 1 (eHH+/education-/iHH-/OC-, 3-month run-in phase 2 (eHH+/education+/iHH+/OC+, 15-month implementation phase 3 (eHH+/education+/iHH+/OC+, and 6-month post-implementation phase 4 (eHH+/education-/iHH+/OC-.A total of 2553 ventilator-days were observed. VAP incidences (events/1000 ventilator days in phase 1-4 were 39.1, 40.5, 15.9, and 20.4, respectively. VAP was significantly reduced by 59% in phase 3 (vs. phase 1, incidence rate ratio [IRR] 0.41, P = 0.002, but rebounded in phase 4. Moreover, VAP incidence was inversely correlated to compliance of OC (r2 = 0.531, P = 0.001 and eHH (r2 = 0.878, P < 0.001, but not applied for iHH, despite iHH compliance was higher than eHH compliance during phase 2 to 4. Compared to eHH, iHH provided more efficient and faster improvements for standard HH practice. The minimal compliances required for significant VAP reduction were 85% and 75% for OC and eHH (both P < 0.05, IRR 0.28 and 0.42, respectively.This simplified prevention bundle effectively reduces early-onset VAP incidence. An unaware HH compliance correlates with VAP incidence. A knowing HH audit provides better improvement in HH practice. Accordingly, we suggest

  16. Youth Mental Health Services Utilization Rates After a Large-Scale Social Media Campaign: Population-Based Interrupted Time-Series Analysis.

    Science.gov (United States)

    Booth, Richard G; Allen, Britney N; Bray Jenkyn, Krista M; Li, Lihua; Shariff, Salimah Z

    2018-04-06

    Despite the uptake of mass media campaigns, their overall impact remains unclear. Since 2011, a Canadian telecommunications company has operated an annual, large-scale mental health advocacy campaign (Bell Let's Talk) focused on mental health awareness and stigma reduction. In February 2012, the campaign began to explicitly leverage the social media platform Twitter and incented participation from the public by promising donations of Can $0.05 for each interaction with a campaign-specific username (@Bell_LetsTalk). The intent of the study was to examine the impact of this 2012 campaign on youth outpatient mental health services in the province of Ontario, Canada. Monthly outpatient mental health visits (primary health care and psychiatric services) were obtained for the Ontario youth aged 10 to 24 years (approximately 5.66 million visits) from January 1, 2006 to December 31, 2015. Interrupted time series, autoregressive integrated moving average modeling was implemented to evaluate the impact of the campaign on rates of monthly outpatient mental health visits. A lagged intervention date of April 1, 2012 was selected to account for the delay required for a patient to schedule and attend a mental health-related physician visit. The inclusion of Twitter into the 2012 Bell Let's Talk campaign was temporally associated with an increase in outpatient mental health utilization for both males and females. Within primary health care environments, female adolescents aged 10 to 17 years experienced a monthly increase in the mental health visit rate from 10.2/1000 in April 2006 to 14.1/1000 in April 2015 (slope change of 0.094 following campaign, Pcampaign, Pcampaign (slope change of 0.005, P=.02; slope change of 0.003, P=.005, respectively). For young adults aged 18 to 24 years, females who used primary health care experienced the most significant increases in mental health visit rates from 26.5/1000 in April 2006 to 29.2/1000 in April 2015 (slope change of 0.17 following

  17. Learning about interruptions

    DEFF Research Database (Denmark)

    Brandrup, Morten

    ‘Interruption’ is a well described phenomenon within health-care. This study describes a field study in which nurses at a surgical ward desired to gain insights to what they experienced as interruptions from phone calls of the coordinating nurse. Employing an effects-driven approach data about...... the frequency and types of phone calls was collected using a tailored experience sampling tool. The data as well as the data became a way for the nurses to learn about the problem and use it as a stepping stone for discussing possible solutions....

  18. The Effects of Interruptions on Oncologists' Patient Assessment and Medication Ordering Practices

    Directory of Open Access Journals (Sweden)

    Patricia L. Trbovich

    2013-01-01

    Full Text Available Interruptions are causal factors in medication errors. Although researchers have assessed the nature and frequency of interruptions during medication administration, there has been little focus on understanding their effects during medication ordering. The goal of this research was to examine the nature, frequency, and impact of interruptions on oncologists' ordering practices. Direct observations were conducted at a Canadian cancer treatment facility to (1 document the nature, frequency, and timing of interruptions during medication ordering, and (2 quantify the use of coping mechanisms by oncologists. On average, oncologists were interrupted 17 % of their time, and were frequently interrupted during safety-critical stages of medication ordering. When confronted with interruptions, oncologists engaged/multitasked more often than resorting to deferring/blocking. While some interruptions are necessary forms of communication, efforts must be made to reduce unnecessary interruptions during safety-critical tasks, and to develop interventions that increase oncologists' resiliency to inevitable interruptions.

  19. Compromised local control due to treatment interruptions and late treatment breaks in early glottic cancer: Population-based outcomes study supporting need for intensified treatment schedules

    International Nuclear Information System (INIS)

    Groome, Patti A.; O'Sullivan, Brian; Mackillop, William J.; Jackson, Lynda D.; Schulze, Karleen M.Math.; Irish, Jonathan C.; Warde, Padraig R.; Schneider, Ken M.; Mackenzie, Robert G.; Hodson, D. Ian; Hammond, J. Alex; Gulavita, Sunil P.P.; Eapen, Libni J.; Dixon, Peter F. M.B.; Bissett, Randy J.

    2006-01-01

    Purpose: This population-based study describes the treatment of early glottic cancer in Ontario, Canada and assesses whether treatment variations were associated with treatment effectiveness. Methods and Materials: We studied 491 T1N0 and 213 T2N0 patients. Data abstracted from charts included age, sex, stage, treatment details, disease control, and survival. Results: The total dose ranged from 50 to 70 Gy, and the daily dose ranged from 1.9 to 2.8 Gy. In 90%, treatment duration was between 25 and 50 days. Field sizes, field reductions, beam arrangement, and beam energy varied. Late treatment breaks occurred in 13.6% of T1N0 and 27.1% of T2N0 cases. Local control was comparable to other reports for T1N0 (82% at 5 years), but was only 63.2% in T2N0. Variables associated with local failure in T1N0 were age less than 49 years (relative risk [RR], 3.21; 95% confidence interval [CI], 1.49-6.90) and >3 treatment interruption days (RR, 2.43; 95% CI, 1.00-5.91). In T2N0, these were field reduction (RR, 2.33; 95% CI, 1.23-4.42) and late treatment breaks (RR, 2.19; 95% CI, 1.09-4.41). Conclusion: Some aspects of treatment for early glottic cancer were associated with worse local control. Problems with protracted treatment are of particular concern, underscoring the need for randomized studies to intensify radiotherapy

  20. Analysis of Smartphone Interruptions on Academic General Internal Medicine Wards. Frequent Interruptions may cause a 'Crisis Mode' Work Climate.

    Science.gov (United States)

    Vaisman, Alon; Wu, Robert C

    2017-01-04

    Hospital-based medical services are increasingly utilizing team-based pagers and smartphones to streamline communications. However, an unintended consequence may be higher volumes of interruptions potentially leading to medical error. There is likely a level at which interruptions are excessive and cause a 'crisis mode' climate. We retrospectively collected phone, text messaging, and email interruptions directed to hospital-assigned smartphones on eight General Internal Medicine (GIM) teams at two tertiary care centres in Toronto, Ontario from April 2013 to September 2014. We also calculated the number of times these interruptions exceeded a pre-specified threshold per hour, termed 'crisis mode', defined as at least five interruptions in 30 minutes. We analyzed the correlation between interruptions and date, site, and patient volumes. A total of 187,049 interruptions were collected over an 18-month period. Daily weekday interruptions rose sharply in the morning, peaking between 11 AM to 12 PM and measuring 4.8 and 3.7 mean interruptions/hour at each site, respectively. Mean daily interruptions per team totaled 46.2 ± 3.6 at Site 1 and 39.2 ± 4.2 at Site 2. The 'crisis mode' threshold was exceeded, on average, 2.3 times/day per GIM team during weekdays. In a multivariable linear regression analysis, site (β6.43 CI95% 5.44 - 7.42, ptime.

  1. Chemical control of flowering time

    DEFF Research Database (Denmark)

    Ionescu, Irina Alexandra; Møller, Birger Lindberg; Sánchez Pérez, Raquel

    2017-01-01

    Flowering at the right time is of great importance; it secures seed production and therefore species survival and crop yield. In addition to the genetic network controlling flowering time, there are a number of much less studied metabolites and exogenously applied chemicals that may influence...... on the genetic aspects of flowering time regulation in annuals, but less so in perennials. An alternative to plant breeding approaches is to engineer flowering time chemically via the external application of flower-inducing compounds. This review discusses a variety of exogenously applied compounds used in fruit...

  2. Interrupting Mythic Community

    Directory of Open Access Journals (Sweden)

    Linnell Secomb

    2013-09-01

    Full Text Available If nation is increasingly perceived as a less than honourable institution formed through war, invasion and geo-political territorialisation, and government is widely denounced as the site of political intrigue and the means of subjectification of citizen–voters, community appears to escape this critique and to be viewed as an idyllic formation based on bonds of affinity. However, this romancing of community is disrupted by trans-cultural and sub-cultural formations that expose the fantasy of a harmonious, homogenous community. While community is often conceived as arising organically from familial, tribal or cultural similarity, or as constituted through a common history and shared cultural institutions, this totalising conception of community is interrupted by the demands of difference and heterogeneity and by a questioning of the idyll of community authenticated in myths of archaic origin.

  3. Three axis electronic flight motion simulator real time control system design and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Zhiyuan; Miao, Zhonghua, E-mail: zhonghua-miao@163.com; Wang, Xiaohua [School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200072 (China); Wang, Xuyong [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2014-12-15

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  4. Three axis electronic flight motion simulator real time control system design and implementation.

    Science.gov (United States)

    Gao, Zhiyuan; Miao, Zhonghua; Wang, Xuyong; Wang, Xiaohua

    2014-12-01

    A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

  5. Markets and pricing for interruptible electric power

    International Nuclear Information System (INIS)

    Gedra, T.W.; Varaiya, P.P.

    1993-01-01

    The authors propose a market for interruptible, or callable, forward contracts for electric power, in which the consumer grants the power supplier the right to interrupt a given unit of load in return for a price discount. The callable forward contracts are traded continuously until the time of use. This allows recourse for those customers with uncertain demand, while risk-averse consumers can minimize their price risk by purchasing early. Callable forward contracts are simple in form, and can be directly incorporated into the utility's economic dispatch procedure

  6. The impact of national-level interventions to improve hygiene on the incidence of irritant contact dermatitis in healthcare workers: changes in incidence from 1996 to 2012 and interrupted times series analysis.

    Science.gov (United States)

    Stocks, S J; McNamee, R; Turner, S; Carder, M; Agius, R M

    2015-07-01

    Reducing healthcare-associated infections (HCAI) has been a priority in the U.K. over recent decades and this has been reflected in interventions focusing on improving hygiene procedures. To evaluate whether these interventions coincided with an increased incidence of work-related irritant contact dermatitis (ICD) attributed to hand hygiene or/and other hygiene measures in healthcare workers (HCWs). A quasi-experimental (interrupted time series) design was used to compare trends in incidence of ICD in HCWs attributed to hygiene before and after interventions to reduce HCAI with trends in the same periods in control groups (ICD in other workers). Cases of ICD reported to a U.K. surveillance scheme from 1996 to 2012 were analysed. The time periods compared were defined objectively based on the dates of the publication of national evidence-based guidelines, the U.K. Health Act 2006 and the Cleanyourhands campaign. The reported incidence of ICD in HCWs attributed to hygiene has increased steadily from 1996 to 2012 [annual incidence rate ratio (95% confidence interval): hand hygiene only 1.10 (1.07-1.12); all hygiene 1.05 (1.03-1.07)], whereas the incidence in other workers is declining. An increase in incidence of ICD in HCWs attributed to hand hygiene was observed at the beginning of the Cleanyourhands campaign. The increasing incidence of ICD in HCWs combined with the popularity of interventions to reduce HCAI warrants increased efforts towards identifying products and implementing practices posing the least risk of ICD. © 2015 British Association of Dermatologists.

  7. Evaluation of the national Cleanyourhands campaign to reduce Staphylococcus aureus bacteraemia and Clostridium difficile infection in hospitals in England and Wales by improved hand hygiene: four year, prospective, ecological, interrupted time series study.

    Science.gov (United States)

    Stone, Sheldon Paul; Fuller, Christopher; Savage, Joan; Cookson, Barry; Hayward, Andrew; Cooper, Ben; Duckworth, Georgia; Michie, Susan; Murray, Miranda; Jeanes, Annette; Roberts, J; Teare, Louise; Charlett, Andre

    2012-05-03

    To evaluate the impact of the Cleanyourhands campaign on rates of hospital procurement of alcohol hand rub and soap, report trends in selected healthcare associated infections, and investigate the association between infections and procurement. Prospective, ecological, interrupted time series study from 1 July 2004 to 30 June 2008. 187 acute trusts in England and Wales. Installation of bedside alcohol hand rub, materials promoting hand hygiene and institutional engagement, regular hand hygiene audits, rolled out nationally from 1 December 2004. Quarterly (that is, every three months) rates for each trust of hospital procurement of alcohol hand rub and liquid soap; Staphylococcus aureus bacteraemia (meticillin resistant (MRSA) and meticillin sensitive (MSSA)) and Clostridium difficile infection for each trust. Associations between procurement and infection rates assessed by mixed effect Poisson regression model (which also accounted for effect of bed occupancy, hospital type, and timing of other national interventions targeting these infections). Combined procurement of soap and alcohol hand rub tripled from 21.8 to 59.8 mL per patient bed day; procurement rose in association with each phase of the campaign. Rates fell for MRSA bacteraemia (1.88 to 0.91 cases per 10,000 bed days) and C difficile infection (16.75 to 9.49 cases). MSSA bacteraemia rates did not fall. Increased procurement of soap was independently associated with reduced C difficile infection throughout the study (adjusted incidence rate ratio for 1 mL increase per patient bed day 0.993, 95% confidence interval 0.990 to 0.996; P hospital procurement of alcohol rub and soap, which the results suggest has an important role in reducing rates of some healthcare associated infections. National interventions for infection control undertaken in the context of a high profile political drive can reduce selected healthcare associated infections.

  8. Children and Career Interruptions: The Family Gap in Denmark

    DEFF Research Database (Denmark)

    Gupta, Nabanita Datta; Smith, Nina

    2002-01-01

    Abstract: The effect of children and career interruptions on the family gap is analysed based on longitudinal data covering the years 1980-1995. The estimated model controls for unobserved time-constant heterogeneity. The results show that when controlling for unobserved heterogeneity, the negative...... effect of children on mothers' wages disappear, but there are large differences between educational groups and the public and private sector. The main effect of children seems to be a loss of human capital accumulation during child-birth periods. Beside this, there is no indication that children have...

  9. Vacuum interrupters used for the interruption of high dc currents

    International Nuclear Information System (INIS)

    Warren, R.W.

    1977-01-01

    Conventional ac vacuum interrupters are being used to interrupt currents in pulsed energy storage systems. They have been tested with dc currents of up to 37 kA. The limit to the current which can be successfully interrupted has been measured as a function of various parameters. Among these are (1) the size of the interrupter, (2) the magnitude of the counterpulse current, (3) the nature and flux rating of the saturable reactor used, and (4) the kind of ''snubber'' circuit used. Fragmentary data have also been collected on electrode erosion rates and on mechanical failure of the bellows. A description is given of the circuits used in these tests and of the results found for a representative selection of the commercially available domestic interrupters. More recently efforts have been made to increase the values found for the maximum interruptible current. The techniques used have included connecting interrupters in parallel and operating them in an impressed axial magnetic field. The results of this work are discussed

  10. Real-time operating system timing jitter and its impact on motor control

    Science.gov (United States)

    Proctor, Frederick M.; Shackleford, William P.

    2001-12-01

    General-purpose microprocessors are increasingly being used for control applications due to their widespread availability and software support for non-control functions like networking and operator interfaces. Two classes of real-time operating systems (RTOS) exist for these systems. The traditional RTOS serves as the sole operating system, and provides all OS services. Examples include ETS, LynxOS, QNX, Windows CE and VxWorks. RTOS extensions add real-time scheduling capabilities to non-real-time OSes, and provide minimal services needed for the time-critical portions of an application. Examples include RTAI and RTL for Linux, and HyperKernel, OnTime and RTX for Windows NT. Timing jitter is an issue in these systems, due to hardware effects such as bus locking, caches and pipelines, and software effects from mutual exclusion resource locks, non-preemtible critical sections, disabled interrupts, and multiple code paths in the scheduler. Jitter is typically on the order of a microsecond to a few tens of microseconds for hard real-time operating systems, and ranges from milliseconds to seconds in the worst case for soft real-time operating systems. The question of its significance on the performance of a controller arises. Naturally, the smaller the scheduling period required for a control task, the more significant is the impact of timing jitter. Aside from this intuitive relationship is the greater significance of timing on open-loop control, such as for stepper motors, than for closed-loop control, such as for servo motors. Techniques for measuring timing jitter are discussed, and comparisons between various platforms are presented. Techniques to reduce jitter or mitigate its effects are presented. The impact of jitter on stepper motor control is analyzed.

  11. Individual Differences in Working-Memory Capacity and Task Resumption Following Interruptions

    Science.gov (United States)

    Foroughi, Cyrus K.; Werner, Nicole E.; McKendrick, Ryan; Cades, David M.; Boehm-Davis, Deborah A.

    2016-01-01

    Previous research has shown that there is a time cost (i.e., a resumption lag) associated with resuming a task following an interruption and that the longer the duration of the interruption, the greater the time cost (i.e., resumption lag increases as interruption duration increases). The memory-for-goals model (Altmann & Trafton, 2002)…

  12. Stepping Stones and Creating Futures intervention: shortened interrupted time series evaluation of a behavioural and structural health promotion and violence prevention intervention for young people in informal settlements in Durban, South Africa.

    Science.gov (United States)

    Jewkes, Rachel; Gibbs, Andrew; Jama-Shai, Nwabisa; Willan, Samantha; Misselhorn, Alison; Mushinga, Mildred; Washington, Laura; Mbatha, Nompumelelo; Skiweyiya, Yandisa

    2014-12-29

    Gender-based violence and HIV are highly prevalent in the harsh environment of informal settlements and reducing violence here is very challenging. The group intervention Stepping Stones has been shown to reduce men's perpetration of violence in more rural areas, but violence experienced by women in the study was not affected. Economic empowerment interventions with gender training can protect older women from violence, but microloan interventions have proved challenging with young women. We investigated whether combining a broad economic empowerment intervention and Stepping Stones could impact on violence among young men and women. The intervention, Creating Futures, was developed as a new generation of economic empowerment intervention, which enabled livelihood strengthening though helping participants find work or set up a business, and did not give cash or make loans. We piloted Stepping Stones with Creating Futures in two informal settlements of Durban with 232 out of school youth, mostly aged 18-30 and evaluated with a shortened interrupted time series of two baseline surveys and at 28 and 58 weeks post-baseline. 94/110 men and 111/122 women completed the last assessment, 85.5% and 90.2% respectively of those enrolled. To determine trend, we built random effects regression models with each individual as the cluster for each variable, and measured the slope of the line across the time points. Men's mean earnings in the past month increased by 247% from R411 (~$40) to R1015 (~$102, and women's by 278% R 174 (~$17) to R 484 (about $48) (trend test, p < 0.0001). There was a significant reduction in women's experience of the combined measure of physical and/or sexual IPV in the prior three months from 30.3% to 18.9% (p = 0.037). This was not seen for men. However both men and women scored significantly better on gender attitudes and men significantly reduced their controlling practices in their relationship. The prevalence of moderate or severe depression

  13. DNA/MVA Vaccination of HIV-1 Infected Participants with Viral Suppression on Antiretroviral Therapy, followed by Treatment Interruption: Elicitation of Immune Responses without Control of Re-Emergent Virus.

    Science.gov (United States)

    Thompson, Melanie; Heath, Sonya L; Sweeton, Bentley; Williams, Kathy; Cunningham, Pamela; Keele, Brandon F; Sen, Sharon; Palmer, Brent E; Chomont, Nicolas; Xu, Yongxian; Basu, Rahul; Hellerstein, Michael S; Kwa, Suefen; Robinson, Harriet L

    2016-01-01

    GV-TH-01, a Phase 1 open-label trial of a DNA prime—Modified Vaccinia Ankara (MVA) boost vaccine (GOVX-B11), was undertaken in HIV infected participants on antiretroviral treatment (ART) to evaluate safety and vaccine-elicited T cell responses, and explore the ability of elicited CD8+ T cells to control viral rebound during analytical treatment interruption (TI). Nine men who began antiretroviral therapy (ART) within 18 months of seroconversion and had sustained plasma HIV-1 RNA HIV-1 RNA was 140,000 copies/ml and mean baseline CD4 count was 755/μl. Two DNA, followed by 2 MVA, inoculations were given 8 weeks apart. Eight subjects completed all vaccinations and TI. Clinical and laboratory adverse events were generally mild, with no serious or grade 4 events. Only reactogenicity events were considered related to study drug. No treatment emergent viral resistance was seen. The vaccinations did not reduce viral reservoirs and virus re-emerged in all participants during TI, with a median time to re-emergence of 4 weeks. Eight of 9 participants had CD8+ T cells that could be stimulated by vaccine-matched Gag peptides prior to vaccination. Vaccinations boosted these responses as well as eliciting previously undetected CD8+ responses. Elicited T cells did not display signs of exhaustion. During TI, temporal patterns of viral re-emergence and Gag-specific CD8+ T cell expansion suggested that vaccine-specific CD8+ T cells had been stimulated by re-emergent virus in only 2 of 8 participants. In these 2, transient decreases in viremia were associated with Gag selection in known CD8+ T cell epitopes. We hypothesize that escape mutations, already archived in the viral reservoir, plus a poor ability of CD8+ T cells to traffic to and control virus at sites of re-emergence, limited the therapeutic efficacy of the DNA/MVA vaccine. clinicaltrials.gov NCT01378156.

  14. Associations between introduction and withdrawal of a financial incentive and timing of attendance for antenatal care and incidence of small for gestational age: natural experimental evaluation using interrupted time series methods

    Science.gov (United States)

    van der Waal, Zelda; Rushton, Steven; Rankin, Judith

    2018-01-01

    Objectives To determine whether introduction or withdrawal of a maternal financial incentive was associated with changes in timing of first attendance for antenatal care (‘booking’), or incidence of small for gestational age. Design A natural experimental evaluation using interrupted time series analysis. Setting A hospital-based maternity unit in the north of England. Participants 34 589 women (and their live-born babies) who delivered at the study hospital and completed the 25th week of pregnancy in the 75 months before (January 2003 to March 2009), 21 months during (April 2009 to December 2010) and 36 months after (January 2011 to December 2013) the incentive was available. Intervention The Health in Pregnancy Grant was a financial incentive of £190 ($235; €211) payable to pregnant women in the UK from the 25th week of pregnancy, contingent on them receiving routine antenatal care. Primary and secondary outcome measures The primary outcome was mean gestational age at booking. Secondary outcomes were proportion of women booking by 10, 18 and 25 weeks’ gestation; and proportion of babies that were small for gestational age. Results By 21 months after introduction of the grant (ie, immediately prior to withdrawal), compared with what was predicted given prior trends, there was an reduction in mean gestational age at booking of 4.8 days (95% CI 2.3 to 8.2). The comparable figure for 24 months after withdrawal was an increase of 14.0 days (95% CI 2.8 to 16.8). No changes in incidence of small for gestational age babies were seen. Conclusions The introduction of a universal financial incentive for timely attendance at antenatal care was associated with a reduction in mean gestational age at first attendance, but not the proportion of babies that were small for gestational age. Future research should explore the effects of incentives offered at different times in pregnancy and of differing values; and how stakeholders view such incentives. PMID:29391362

  15. Associations between introduction and withdrawal of a financial incentive and timing of attendance for antenatal care and incidence of small for gestational age: natural experimental evaluation using interrupted time series methods.

    Science.gov (United States)

    Adams, Jean; van der Waal, Zelda; Rushton, Steven; Rankin, Judith

    2018-01-31

    To determine whether introduction or withdrawal of a maternal financial incentive was associated with changes in timing of first attendance for antenatal care ('booking'), or incidence of small for gestational age. A natural experimental evaluation using interrupted time series analysis. A hospital-based maternity unit in the north of England. 34 589 women (and their live-born babies) who delivered at the study hospital and completed the 25th week of pregnancy in the 75 months before (January 2003 to March 2009), 21 months during (April 2009 to December 2010) and 36 months after (January 2011 to December 2013) the incentive was available. The Health in Pregnancy Grant was a financial incentive of £190 ($235; €211) payable to pregnant women in the UK from the 25th week of pregnancy, contingent on them receiving routine antenatal care. The primary outcome was mean gestational age at booking. Secondary outcomes were proportion of women booking by 10, 18 and 25 weeks' gestation; and proportion of babies that were small for gestational age. By 21 months after introduction of the grant (ie, immediately prior to withdrawal), compared with what was predicted given prior trends, there was an reduction in mean gestational age at booking of 4.8 days (95% CI 2.3 to 8.2). The comparable figure for 24 months after withdrawal was an increase of 14.0 days (95% CI 2.8 to 16.8). No changes in incidence of small for gestational age babies were seen. The introduction of a universal financial incentive for timely attendance at antenatal care was associated with a reduction in mean gestational age at first attendance, but not the proportion of babies that were small for gestational age. Future research should explore the effects of incentives offered at different times in pregnancy and of differing values; and how stakeholders view such incentives. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No

  16. Interrupting the Interruption: Neoliberalism and the Challenges of an Antiracist School

    Science.gov (United States)

    Meshulam, Assaf; Apple, Michael W.

    2014-01-01

    The article examines a US public elementary bilingual, multicultural school that attempts to interrupt the reproduction of existing relations of dominance and subordination across a variety of differences. The school's experiences illuminate the complex reality of schools as a site of struggle and compromise between at times contradictory…

  17. Interrupting long periods of sitting: good STUFF

    Directory of Open Access Journals (Sweden)

    Rutten Geert M

    2013-01-01

    Full Text Available Abstract There is increasing evidence that sedentary behaviour is in itself a health risk, regardless of the daily amount of moderate to vigorous physical activity. Therefore, sedentary behaviour should be targeted as important health behaviour. It is known that even relatively small changes of health behaviour often require serious efforts from an individual and from people in their environment to become part of their lifestyle. Therefore, interventions to promote healthy behaviours should ideally be simple, easy to perform and easily available. Since sitting is likely to be highly habitual, confrontation with an intervention should almost automatically elicit a reaction of getting up, and thus break up and reduce sitting time. One important prerequisite for successful dissemination of such an intervention could be the use of a recognisable term relating to sedentary behaviour, which should have the characteristics of an effective brand name. To become wide spread, this term may need to meet three criteria: the “Law of the few”, the “Stickiness factor”, and the “Power of context”. For that purpose we introduce STUFF: Stand Up For Fitness. STUFF can be defined as “interrupting long sitting periods by short breaks”, for instance, interrupting sitting every 30 min by standing for at least five minutes. Even though we still need evidence to test the health-enhancing effects of interrupted sitting, we hope that the introduction of STUFF will facilitate the testing of the social, psychological and health effects of interventions to reduce sitting time.

  18. The Impact of a Case of Ebola Virus Disease on Emergency Department Visits in Metropolitan Dallas-Fort Worth, TX, July, 2013-July, 2015: An Interrupted Time Series Analysis.

    Science.gov (United States)

    Molinari, Noelle-Angelique M; LeBlanc, Tanya Telfair; Stephens, William

    2018-03-20

    The first Ebola virus disease (EVD) case in the United States (US) was confirmed September 30, 2014 in a man 45 years old. This event created considerable media attention and there was fear of an EVD outbreak in the US. This study examined whether emergency department (ED) visits changed in metropolitan Dallas-Fort Worth--, Texas (DFW) after this EVD case was confirmed. Using Texas Health Services Region 2/3 syndromic surveillance data and focusing on DFW, interrupted time series analyses were conducted using segmented regression models with autoregressive errors for overall ED visits and rates of several chief complaints, including fever with gastrointestinal distress (FGI). Date of fatal case confirmation was the "event." Results indicated the event was highly significant for ED visits overall (Pcapacity as well as for public health messaging in the wake of a public health emergency.

  19. Opioid interruptions, pain, and withdrawal symptoms in nursing home residents.

    Science.gov (United States)

    Redding, Sarah E; Liu, Sophia; Hung, William W; Boockvar, Kenneth S

    2014-11-01

    Interruptions in opioid use have the potential to cause pain relapse and withdrawal symptoms. The objectives of this study were to observe patterns of opioid interruption during acute illness in nursing home residents and examine associations between interruptions and pain and withdrawal symptoms. Patients from 3 nursing homes in a metropolitan area who were prescribed opioids were assessed for symptoms of pain and withdrawal by researchers blinded to opioid dosage received, using the Brief Pain Inventory Scale and the Clinical Opioid Withdrawal Scale, respectively, during prespecified time periods. The prespecified time periods were 2 weeks after onset of acute illness (eg, urinary tract infection), and 2 weeks after hospital admission and nursing home readmission, if they occurred. Opioid dosing was recorded and a significant interruption was defined as a complete discontinuation or a reduction in dose of >50% for ≥1 day. The covariates age, sex, race, comorbid conditions, initial opioid dose, and initial pain level were recorded. Symptoms pre- and post-opioid interruptions were compared and contrasted with those in a group without opioid interruptions. Sixty-six patients receiving opioids were followed for a mean of 10.9 months and experienced a total of 104 acute illnesses. During 64 (62%) illnesses, patients experienced any reduction in opioid dosing, with a mean (SD) dose reduction of 63.9% (29.9%). During 39 (38%) illnesses, patients experienced a significant opioid interruption. In a multivariable model, residence at 1 of the 3 nursing homes was associated with a lower risk of interruption (odds ratio = 0.073; 95% CI, 0.009 to 0.597; P pain score (difference -0.50 [2.66]; 95% CI, -3.16 to 2.16) and withdrawal score (difference -0.91 [3.12]; 95% CI, -4.03 to 2.21) after the interruption as compared with before interruption. However, when compared with patients without interruptions, patients with interruptions experienced larger increases in pain scores

  20. Customer interruption cost and results

    Energy Technology Data Exchange (ETDEWEB)

    Eua-Arporn, B.; Bisarnbutra, S. [Chulalongkorn Univ., Bangkok (Thailand)

    1997-12-31

    Results of a comprehensive study on short-term direct impacts and consumer interruption costs, incurred as a result of power supply interruption, were discussed. The emphasis was on questionnaire development, general responses and the average customer damage function of some selected sectors. The customer damage function was established for each category of customers (agriculture, industry, mining, wholesale, retail merchandising, residential, etc) as well as for different locations. Results showed that the average customer damage function depended mostly on customer category. Size and location were not significant factors. 5 refs., 7 tabs.

  1. Repetitive Series Interrupter II.

    Science.gov (United States)

    1977-07-01

    nated by other authorized documents. The citation of trade names and names of manufacturers is this report is not to be construed as official... intergrating inductor Magnet circuit load resistance Pulse-forming network load resistance Fault network load resistance Time delay between TUT fire and

  2. Measuring device for control rod driving time

    International Nuclear Information System (INIS)

    Tanaka, Kazuhiko; Hanabusa, Masatoshi.

    1993-01-01

    The present invention concerns a measuring device for control driving time having a function capable of measuring a selected control rod driving time and measuring an entire control rod driving time simultaneously. A calculation means and a store means for the selected rod control rod driving time, and a calculation means and a store means for the entire control rod driving time are disposed individually. Each of them measures the driving time and stores the data independent of each other based on a selected control rod insert ion signal and an entire control rod insertion signal. Even if insertion of selected and entire control rods overlaps, each of the control rod driving times can be measured reliably to provide an advantageous effect capable of more accurately conducting safety evaluation for the nuclear reactor based on the result of the measurement. (N.H.)

  3. Similar decreases in local tumor control are calculated for treatment protraction and for interruptions in the radiotherapy of carcinoma of the larynx in four centers

    International Nuclear Information System (INIS)

    Robertson, Chris; Robertson, A. Gerald; Hendry, Jolyon H.; Roberts, Stephen A.; Slevin, Nicholas J.; Duncan, William B.; MacDougall, R. Hugh; Kerr, Gillian R.; O'Sullivan, B.; Keane, Thomas J.

    1998-01-01

    Purpose: Data on patients with cancer of the larynx are analyzed using statistical models to estimate the effect of gaps in the treatment time on the local control of the tumor. Methods and Materials: Patients from four centers, Edinburgh, Glasgow, Manchester, and Toronto, with carcinoma of the larynx and treated by radiotherapy were followed up and the disease-free period recorded. In all centers the end point was control of the primary tumor after irradiation alone. The local control rates at ≥2 years, P c , were analyzed by log linear models, and Cox proportional hazard models were used to model the disease-free period. Results: T stage, nodal involvement, and site of the tumor were important determinants of the disease-free interval, as was the radiation schedule used. Elongation of the treatment time by 1 day, or a gap of 1 day, was associated with a decrease in P c of 0.68% per day for P c = 0.80, with a 95% confidence interval of (0.28, 1.08)%. An increase of 5 days was associated with a 3.5% reduction in P c from 0.80 to 0.77. At P c = 0.60 an increase of 5 days was associated with an 7.9% decrease in P c . The time factor in the Linear Quadratic model, γ/α, was estimated as 0.89 Gy/day, 95% confidence interval (0.35, 1.43) Gy/day. Conclusions: Any gaps (public holidays are the majority) in the treatment schedule have the same deleterious effect on the disease free period as an increase in the prescribed treatment time. For a schedule, where dose and fraction number are specified, any gap in treatment is potentially damaging

  4. Coping with interruptions in clinical nursing - a qualitative study

    DEFF Research Database (Denmark)

    Laustsen, Sussie; Brahe, Liselotte

    2018-01-01

    phenomenological approach. METHODS: Observations were performed combined with semi-structured qualitative interviews. RESULTS: Managing interruptions depend on level of competence, working environment, dialogue and matching of expectations, collegial roles and implicit rules. Working procedures impact on how......AIMS AND OBJECTIVES: To gain knowledge on how nurses' cope with interruptions in clinical practice. BACKGROUND: Interruptions may delay work routines and result in wasted time, disorganised planning and ineffective working procedures, affecting nurses' focus and overview in different ways. Research......: Culture work and matching of expectations are important to reflect on and discuss personal- and group behaviour caused by interruptions. We need to focus on the role of each nurse in the professional team, types of personality and unspoken rules. Professional competencies for example prioritising, keeping...

  5. Teaching Students to Request the Continuation of Routine Activities by Using Time Delay and Decreasing Physical Assistance in the Context of Chain Interruption.

    Science.gov (United States)

    Gee, Kathleen; And Others

    1991-01-01

    Three students (ages 5-10) with profound intellectual, sensory, and physical disabilities were taught to activate a communication device to request the continuation of activities in which they were involved. The intervention consisted of a consistent response interval and increasing time delay paired with decreasing physical assistance in…

  6. DNA/MVA Vaccination of HIV-1 Infected Participants with Viral Suppression on Antiretroviral Therapy, followed by Treatment Interruption: Elicitation of Immune Responses without Control of Re-Emergent Virus.

    Directory of Open Access Journals (Sweden)

    Melanie Thompson

    Full Text Available GV-TH-01, a Phase 1 open-label trial of a DNA prime—Modified Vaccinia Ankara (MVA boost vaccine (GOVX-B11, was undertaken in HIV infected participants on antiretroviral treatment (ART to evaluate safety and vaccine-elicited T cell responses, and explore the ability of elicited CD8+ T cells to control viral rebound during analytical treatment interruption (TI. Nine men who began antiretroviral therapy (ART within 18 months of seroconversion and had sustained plasma HIV-1 RNA <50 copies/mL for at least 6 months were enrolled. Median age was 38 years, median pre-ART HIV-1 RNA was 140,000 copies/ml and mean baseline CD4 count was 755/μl. Two DNA, followed by 2 MVA, inoculations were given 8 weeks apart. Eight subjects completed all vaccinations and TI. Clinical and laboratory adverse events were generally mild, with no serious or grade 4 events. Only reactogenicity events were considered related to study drug. No treatment emergent viral resistance was seen. The vaccinations did not reduce viral reservoirs and virus re-emerged in all participants during TI, with a median time to re-emergence of 4 weeks. Eight of 9 participants had CD8+ T cells that could be stimulated by vaccine-matched Gag peptides prior to vaccination. Vaccinations boosted these responses as well as eliciting previously undetected CD8+ responses. Elicited T cells did not display signs of exhaustion. During TI, temporal patterns of viral re-emergence and Gag-specific CD8+ T cell expansion suggested that vaccine-specific CD8+ T cells had been stimulated by re-emergent virus in only 2 of 8 participants. In these 2, transient decreases in viremia were associated with Gag selection in known CD8+ T cell epitopes. We hypothesize that escape mutations, already archived in the viral reservoir, plus a poor ability of CD8+ T cells to traffic to and control virus at sites of re-emergence, limited the therapeutic efficacy of the DNA/MVA vaccine.clinicaltrials.gov NCT01378156.

  7. Current interruption by density depression

    International Nuclear Information System (INIS)

    Wagner, J.S.; Tajima, T.; Akasofu, S.I.

    1985-04-01

    Using a one-dimensional electrostatic particle code, we examine processes associated with current interruption in a collisionless plasma when a density depression is present along the current channel. Current interruption due to double layers was suggested by Alfven and Carlqvist (1967) as a cause of solar flares. At a local density depression, plasma instabilities caused by an electron current flow are accentuated, leading to current disruption. Our simulation study encompasses a wide range of the parameters in such a way that under appropriate conditions, both the Alfven and Carlqvist (1967) regime and the Smith and Priest (1972) regime take place. In the latter regime the density depression decays into a stationary structure (''ion-acoustic layer'') which spawns a series of ion-acoustic ''solitons'' and ion phase space holes travelling upstream. A large inductance of the current circuit tends to enhance the plasma instabilities

  8. Time-optimal control with finite bandwidth

    Science.gov (United States)

    Hirose, M.; Cappellaro, P.

    2018-04-01

    Time-optimal control theory provides recipes to achieve quantum operations with high fidelity and speed, as required in quantum technologies such as quantum sensing and computation. While technical advances have achieved the ultrastrong driving regime in many physical systems, these capabilities have yet to be fully exploited for the precise control of quantum systems, as other limitations, such as the generation of higher harmonics or the finite response time of the control apparatus, prevent the implementation of theoretical time-optimal control. Here we present a method to achieve time-optimal control of qubit systems that can take advantage of fast driving beyond the rotating wave approximation. We exploit results from time-optimal control theory to design driving protocols that can be implemented with realistic, finite-bandwidth control fields, and we find a relationship between bandwidth limitations and achievable control fidelity.

  9. Procedural Error and Task Interruption

    Science.gov (United States)

    2016-09-30

    interruption. A cognitive model we discuss below explains this effect in terms of increases in performance speed having the effect of compressing memory for...performance, and pilot data suggest that the task can distinguish between cognitive processes that are impaired by sleep deprivation and those that are...David Z. Hambrick Technical contact: Erik M. Altmann Michigan State University Department of Psychology 316 Physics Rd, Room 298A East Lansing

  10. Early counterpulse technique applied to vacuum interrupters

    International Nuclear Information System (INIS)

    Warren, R.W.

    1979-01-01

    Interruption of dc currents using counterpulse techniques is investigated with vacuum interrupters and a novel approach in which the counterpulse is applied before contact separation. Important increases have been achieved in this way in the maximum interruptible current and large reductions in contact erosion. The factors establishing these new limits are presented and ways are discussed to make further improvements to the maximum interruptible current

  11. Impact of Florida's prescription drug monitoring program and pill mill law on high-risk patients: A comparative interrupted time series analysis.

    Science.gov (United States)

    Chang, Hsien-Yen; Murimi, Irene; Faul, Mark; Rutkow, Lainie; Alexander, G Caleb

    2018-04-01

    We quantified the effects of Florida's prescription drug monitoring program and pill mill law on high-risk patients. We used QuintilesIMS LRx Lifelink data to identify patients receiving prescription opioids in Florida (intervention state, N: 1.13 million) and Georgia (control state, N: 0.54 million). The preintervention, intervention, and postintervention periods were July 2010 to June 2011, July 2011 to September 2011, and October 2011 to September 2012. We identified 3 types of high-risk patients: (1) concomitant users: patients with concomitant use of benzodiazepines and opioids; (2) chronic users: long-term, high-dose, opioid users; and (3) opioid shoppers: patients receiving opioids from multiple sources. We compared changes in opioid prescriptions between Florida and Georgia before and after policy implementation among high-risk/low-risk patients. Our monthly measures included (1) average morphine milligram equivalent per transaction, (2) total opioid volume across all prescriptions, (3) average days supplied per transaction, and (4) total number of opioid prescriptions dispensed. Among opioid-receiving individuals in Florida, 6.62% were concomitant users, 1.96% were chronic users, and 0.46% were opioid shoppers. Following policy implementation, Florida's high-risk patients experienced relative reductions in morphine milligram equivalent (opioid shoppers: -1.08 mg/month, 95% confidence interval [CI] -1.62 to -0.54), total opioid volume (chronic users: -4.58 kg/month, CI -5.41 to -3.76), and number of dispensed opioid prescriptions (concomitant users: -640 prescriptions/month, CI -950 to -340). Low-risk patients generally did not experience statistically significantly relative reductions. Compared with Georgia, Florida's prescription drug monitoring program and pill mill law were associated with large relative reductions in prescription opioid utilization among high-risk patients. Copyright © 2018 John Wiley & Sons, Ltd.

  12. Early counterpulse technique applied to vacuum interrupters

    International Nuclear Information System (INIS)

    Warren, R.W.

    1979-11-01

    Interruption of dc currents using counterpulse techniques is investigated with vacuum interrupters and a novel approach in which the counterpulse is applied before contact separation. Important increases have been achieved in this way in the maximum interruptible current as well as large reductions in contact erosion. The factors establishing these new limits are presented and ways are discussed to make further improvements

  13. Long-term effect of fee-for-service-based reimbursement cuts on processes and outcomes of care for stroke: interrupted time-series study from Taiwan.

    Science.gov (United States)

    Tung, Yu-Chi; Chang, Guann-Ming; Cheng, Shou-Hsia

    2015-01-01

    As healthcare spending continues to increase, reimbursement cuts have become 1 type of healthcare reform to contain costs. Little is known about the long-term impact of cuts in reimbursement, especially under a global budget cap with fee-for-service (FFS) reimbursement, on processes and outcomes of care. The FFS-based reimbursement cuts have been implemented since July 2002 in Taiwan. We examined the long-term association of FFS-based reimbursement cuts with trends in processes and outcomes of care for stroke. We analyzed all 411,487 patients with stroke admitted to general acute care hospitals in Taiwan during the period 1997 to 2010 through Taiwan's National Health Insurance Research Database. We used a quasi-experimental design with quarterly measures of healthcare utilization and outcomes and used segmented autoregressive integrated moving average models for the analysis. After accounting for secular trends and other confounders, the implementation of the FFS-based reimbursement cuts was associated with trend changes in computed tomography/magnetic resonance imaging scanning (0.31% per quarter; P=0.013), antiplatelet/anticoagulant use (-0.20% per quarter; Pprocesses and outcomes of care over time. However, the reimbursement cuts from the FFS-based global budget cap are associated with trend changes in processes and outcomes of care for stroke. The FFS-based reimbursement cuts may have long-term positive and negative associations with stroke care. © 2014 American Heart Association, Inc.

  14. Trends in the utilization of dental outpatient services affected by the expansion of health care benefits in South Korea to include scaling: a 6-year interrupted time-series study.

    Science.gov (United States)

    Park, Hee-Jung; Lee, Jun Hyup; Park, Sujin; Kim, Tae-Il

    2018-02-01

    This study utilized a strong quasi-experimental design to test the hypothesis that the implementation of a policy to expand dental care services resulted in an increase in the usage of dental outpatient services. A total of 45,650,000 subjects with diagnoses of gingivitis or advanced periodontitis who received dental scaling were selected and examined, utilizing National Health Insurance claims data from July 2010 through November 2015. We performed a segmented regression analysis of the interrupted time-series to analyze the time-series trend in dental costs before and after the policy implementation, and assessed immediate changes in dental costs. After the policy change was implemented, a statistically significant 18% increase occurred in the observed total dental cost per patient, after adjustment for age, sex, and residence area. In addition, the dental costs of outpatient gingivitis treatment increased immediately by almost 47%, compared with a 15% increase in treatment costs for advanced periodontitis outpatients. This policy effect appears to be sustainable. The introduction of the new policy positively impacted the immediate and long-term outpatient utilization of dental scaling treatment in South Korea. While the policy was intended to entice patients to prevent periodontal disease, thus benefiting the insurance system, our results showed that the policy also increased treatment accessibility for potential periodontal disease patients and may improve long-term periodontal health in the South Korean population.

  15. Trends in the utilization of dental outpatient services affected by the expansion of health care benefits in South Korea to include scaling: a 6-year interrupted time-series study

    Science.gov (United States)

    2018-01-01

    Purpose This study utilized a strong quasi-experimental design to test the hypothesis that the implementation of a policy to expand dental care services resulted in an increase in the usage of dental outpatient services. Methods A total of 45,650,000 subjects with diagnoses of gingivitis or advanced periodontitis who received dental scaling were selected and examined, utilizing National Health Insurance claims data from July 2010 through November 2015. We performed a segmented regression analysis of the interrupted time-series to analyze the time-series trend in dental costs before and after the policy implementation, and assessed immediate changes in dental costs. Results After the policy change was implemented, a statistically significant 18% increase occurred in the observed total dental cost per patient, after adjustment for age, sex, and residence area. In addition, the dental costs of outpatient gingivitis treatment increased immediately by almost 47%, compared with a 15% increase in treatment costs for advanced periodontitis outpatients. This policy effect appears to be sustainable. Conclusions The introduction of the new policy positively impacted the immediate and long-term outpatient utilization of dental scaling treatment in South Korea. While the policy was intended to entice patients to prevent periodontal disease, thus benefiting the insurance system, our results showed that the policy also increased treatment accessibility for potential periodontal disease patients and may improve long-term periodontal health in the South Korean population. PMID:29535886

  16. Discrete-time nonlinear sliding mode controller

    African Journals Online (AJOL)

    user

    Keywords: Discrete-time delay system, Sliding mode control, nonlinear sliding ... of engineering systems such as chemical process control, delay in the actuator ...... instrumentation from Motilal Nehru National Institute of Technology (MNNIT),.

  17. Distributed digital real-time control system for TCV tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Le, H.B. [École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Association EURATOM-Confédération Suisse, CH-1015 Lausanne (Switzerland); Felici, F. [Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Paley, J.I.; Duval, B.P.; Moret, J.-M.; Coda, S.; Sauter, O.; Fasel, D.; Marmillod, P. [École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Association EURATOM-Confédération Suisse, CH-1015 Lausanne (Switzerland)

    2014-03-15

    Coder), into a Linux shared library (“.so” file) and distributed to target nodes in the discharge preparation phase. During the TCV discharge, an application on each node is executed that dynamically loads the shared library at runtime. In order to obtain reliable and reproducible real time execution of the algorithm, all interrupts to the CPU on each node are suspended just before firing the shot and re-enabled afterwards. Since installation, the new digital control system has been used for a multitude of plasma control applications, ranging from basic experiments of coil current and density control to advanced experiments of MHD (magnetohydrodynamics) and plasma profile control, as well as real-time plasma transport simulations. Recently, a real-time version of a plasma equilibrium reconstruction code was developed and implemented, providing the future possibility to control the plasma shape and profiles directly during the discharge evolution. This paper presents the architecture of the new control system, its integration into the TCV plant and a sample of control applications used for TCV plasma discharges.

  18. Time management training and perceived control of time at work.

    Science.gov (United States)

    Häfner, Alexander; Stock, Armin

    2010-01-01

    The purpose of the present study was to examine the effects of time management training, which was based on psychological theory and research, on perceived control of time, perceived stress, and performance at work. The authors randomly assigned 71 employees to a training group (n = 35) or a waiting-list control group (n = 36). As hypothesized, time management training led to an increase in perceived control of time and a decrease in perceived stress. Time management training had no impact on different performance indicators. In particular, the authors explored the use and the perceived usefulness of the techniques taught. Participants judged the taught techniques as useful, but there were large differences concerning the actual use of the various techniques.

  19. Time-resolved x-ray diffraction measurements of high-density InAs quantum dots on Sb/GaAs layers and the suppression of coalescence by Sb-irradiated growth interruption

    International Nuclear Information System (INIS)

    Kakuda, Naoki; Yamaguchi, Koichi; Kaizu, Toshiyuki; Takahasi, Masamitu; Fujikawa, Seiji

    2010-01-01

    Self-assembly of high-density InAs quantum dots (QDs) on Sb-irradiated GaAs buffer layers was observed in-situ by a time-resolved X-ray diffraction (XRD) technique using a combination of XRD and molecular beam epitaxy. Evolution of dot height and lattice constant was analyzed during InAs QD growth and subsequent growth interruption (GI), and as a result, dislocated giant dots due to coalescence and coherent dots were separately evaluated. An Sb-irradiated GI (Sb-GI) method to be applied after InAs growth was attempted for the suppression of coalescence. Using this method, the XRD intensity of giant dots decreased, and the photoluminescence intensity of InAs QDs was enhanced. High-density InAs QDs without giant dots were produced by using the combination of the QD growth on the Sb-irradiated GaAs buffer layers and the Sb-GI. (author)

  20. Timing and motor control in drumming

    DEFF Research Database (Denmark)

    Dahl, Sofia; Grossbach, Michael; Altenmüller, Eckart

    the stick movement becomes increasingly difficult, sometimes resulting in irregularities in timing and/or striking force. Timing irregularities can also be a revealing sign of motor control problems, such as focal dystonia (Jabusch, Vauth & Altenmüller, 2004). The "breakdown" in motor control can therefore...

  1. Minimal Time Problem with Impulsive Controls

    Energy Technology Data Exchange (ETDEWEB)

    Kunisch, Karl, E-mail: karl.kunisch@uni-graz.at [University of Graz, Institute for Mathematics and Scientific Computing (Austria); Rao, Zhiping, E-mail: zhiping.rao@ricam.oeaw.ac.at [Austrian Academy of Sciences, Radon Institute of Computational and Applied Mathematics (Austria)

    2017-02-15

    Time optimal control problems for systems with impulsive controls are investigated. Sufficient conditions for the existence of time optimal controls are given. A dynamical programming principle is derived and Lipschitz continuity of an appropriately defined value functional is established. The value functional satisfies a Hamilton–Jacobi–Bellman equation in the viscosity sense. A numerical example for a rider-swing system is presented and it is shown that the reachable set is enlargered by allowing for impulsive controls, when compared to nonimpulsive controls.

  2. Generation of Induced Progenitor-like Cells from Mature Epithelial Cells Using Interrupted Reprogramming

    Directory of Open Access Journals (Sweden)

    Li Guo

    2017-12-01

    Full Text Available Summary: A suitable source of progenitor cells is required to attenuate disease or affect cure. We present an “interrupted reprogramming” strategy to generate “induced progenitor-like (iPL cells” using carefully timed expression of induced pluripotent stem cell reprogramming factors (Oct4, Sox2, Klf4, and c-Myc; OSKM from non-proliferative Club cells. Interrupted reprogramming allowed controlled expansion yet preservation of lineage commitment. Under clonogenic conditions, iPL cells expanded and functioned as a bronchiolar progenitor-like population to generate mature Club cells, mucin-producing goblet cells, and cystic fibrosis transmembrane conductance regulator (CFTR-expressing ciliated epithelium. In vivo, iPL cells can repopulate CFTR-deficient epithelium. This interrupted reprogramming process could be metronomically applied to achieve controlled progenitor-like proliferation. By carefully controlling the duration of expression of OSKM, iPL cells do not become pluripotent, and they maintain their memory of origin and retain their ability to efficiently return to their original phenotype. A generic technique to produce highly specified populations may have significant implications for regenerative medicine. : In this article Waddell, Nagy, and colleagues present an “interrupted reprogramming” strategy to produce highly specified functional “induced progenitor-like cells” from mature quiescent cells. They propose that careful control of the duration of transient expression of iPSC reprogramming factors (OSKM allows controlled expansion yet preservation of parental lineage without traversing the pluripotent state. Keywords: generation of induced progenitor-like cells

  3. Pulsed interrupter and method of operation

    Science.gov (United States)

    Drake, Joel Lawton; Kratz, Robert

    2015-06-09

    Some embodiments provide interrupter systems comprising: a first electrode; a second electrode; a piston movably located at a first position and electrically coupled with the first and second electrodes establishing a closed state, the piston comprises an electrical conductor that couples with the first and second electrodes providing a conductive path; an electromagnetic launcher configured to, when activated, induce a magnetic field pulse causing the piston to move away from the electrical coupling with the first and second electrodes establishing an open circuit between the first and second electrodes; and a piston control system comprising a piston arresting system configured to control a deceleration of the piston following the movement of the piston induced by the electromagnetic launcher such that the piston is not in electrical contact with at least one of the first electrode and the second electrode when in the open state.

  4. Simulation-Based Testing of Pager Interruptions During Laparoscopic Cholecystectomy.

    Science.gov (United States)

    Sujka, Joseph A; Safcsak, Karen; Bhullar, Indermeet S; Havron, William S

    2018-01-30

    To determine if pager interruptions affect operative time, safety, or complications and management of pager issues during a simulated laparoscopic cholecystectomy. Twelve surgery resident volunteers were tested on a Simbionix Lap Mentor II simulator. Each resident performed 6 randomized simulated laparoscopic cholecystectomies; 3 with pager interruptions (INT) and 3 without pager interruptions (NO-INT). The pager interruptions were sent in the form of standardized patient vignettes and timed to distract the resident during dissection of the critical view of safety and clipping of the cystic duct. The residents were graded on a pass/fail scale for eliciting appropriate patient history and management of the pager issue. Data was extracted from the simulator for the following endpoints: operative time, safety metrics, and incidence of operative complications. The Mann-Whitney U test and contingency table analysis were used to compare the 2 groups (INT vs. NO-INT). Level I trauma center; Simulation laboratory. Twelve general surgery residents. There was no significant difference between the 2 groups in any of the operative endpoints as measured by the simulator. However, in the INT group, only 25% of the time did the surgery residents both adequately address the issue and provide effective patient management in response to the pager interruption. Pager interruptions did not affect operative time, safety, or complications during the simulated procedure. However, there were significant failures in the appropriate evaluations and management of pager issues. Consideration for diversion of patient care issues to fellow residents not operating to improve quality and safety of patient care outside the operating room requires further study. Copyright © 2018. Published by Elsevier Inc.

  5. Work Time Control and Sleep Disturbances

    DEFF Research Database (Denmark)

    Salo, Paula; Ala-Mursula, Leena; Rod, Naja Hulvej

    2014-01-01

    OBJECTIVES: Employee control over work times has been associated with favorable psychosocial and health-related outcomes, but the evidence regarding sleep quality remains inconclusive. We examined cross-sectional and prospective associations between work time control and sleep disturbances...... in a large working population, taking into account total hours worked. METHODS: The data were from a full-panel longitudinal cohort study of Finnish public sector employees who responded to questions on work time control and sleep disturbances in years 2000-2001, 2004-2005, 2008-2009, and 2012. The analysis....... RESULTS: Consistently in both cross-sectional and longitudinal models, less control over work time was associated with greater sleep disturbances in the total population and among those working normal 40-hour weeks. Among participants working more than 40 hours a week, work time that was both very high...

  6. Time Optimal Control Laws for Bilinear Systems

    Directory of Open Access Journals (Sweden)

    Salim Bichiou

    2018-01-01

    Full Text Available The aim of this paper is to determine the feedforward and state feedback suboptimal time control for a subset of bilinear systems, namely, the control sequence and reaching time. This paper proposes a method that uses Block pulse functions as an orthogonal base. The bilinear system is projected along that base. The mathematical integration is transformed into a product of matrices. An algebraic system of equations is obtained. This system together with specified constraints is treated as an optimization problem. The parameters to determine are the final time, the control sequence, and the states trajectories. The obtained results via the newly proposed method are compared to known analytical solutions.

  7. Advanced concepts in accelerator timing control

    International Nuclear Information System (INIS)

    Frankel, R.; Salwen, C.

    1988-01-01

    The control system for the Booster accelerator presently under construction at BNL includes a timing section with serial high speed coded data distribution, computer based encoders for both real time and field driven clocks and a method of easily tracking the performance and reliability of these timing streams. We have developed a simple method for the generation of timing which operates to produce pulses which may be repeated as desired with minimal latency

  8. The mythology of anticoagulation therapy interruption for dental surgery.

    Science.gov (United States)

    Wahl, Michael J

    2018-01-01

    Continuous anticoagulation therapy is used to prevent heart attacks, strokes, and other embolic complications. When patients receiving anticoagulation therapy undergo dental surgery, a decision must be made about whether to continue anticoagulation therapy and risk bleeding complications or briefly interrupt anticoagulation therapy and increase the risk of developing embolic complications. Results from decades of studies of thousands of dental patients receiving anticoagulation therapy reveal that bleeding complications requiring more than local measures for hemostasis have been rare and never fatal. However, embolic complications (some of which were fatal and others possibly permanently debilitating) sometimes have occurred in patients whose anticoagulation therapy was interrupted for dental procedures. Although there is now virtually universal consensus among national medical and dental groups and other experts that anticoagulation therapy should not be interrupted for most dental surgery, there are still some arguments made supporting anticoagulation therapy interruption. An analysis of these arguments shows them to be based on a collection of myths and half-truths rather than on logical scientific conclusions. The time has come to stop anticoagulation therapy interruption for dental procedures. Copyright © 2018 American Dental Association. Published by Elsevier Inc. All rights reserved.

  9. Integrated HIV-Care Into Primary Health Care Clinics and the Influence on Diabetes and Hypertension Care: An Interrupted Time Series Analysis in Free State, South Africa Over 4 Years.

    Science.gov (United States)

    Rawat, Angeli; Uebel, Kerry; Moore, David; Yassi, Annalee

    2018-04-15

    Noncommunicable diseases (NCDs), specifically diabetes and hypertension, are rising in high HIV-burdened countries such as South Africa. How integrated HIV care into primary health care (PHC) influences NCD care is unknown. We aimed to understand whether differences existed in NCD care (pre- versus post-integration) and how changes may relate to HIV patient numbers. Public sector PHC clinics in Free State, South Africa. Using a quasiexperimental design, we analyzed monthly administrative data on 4 indicators for diabetes and hypertension (clinic and population levels) during 4 years as HIV integration was implemented in PHC. Data represented 131 PHC clinics with a catchment population of 1.5 million. We used interrupted time series analysis at ±18 and ±30 months from HIV integration in each clinic to identify changes in trends postintegration compared with those in preintegration. We used linear mixed-effect models to study relationships between HIV and NCD indicators. Patients receiving antiretroviral therapy in the 131 PHC clinics studied increased from 1614 (April 2009) to 57, 958 (April 2013). Trends in new diabetes patients on treatment remained unchanged. However, population-level new hypertensives on treatment decreased at ±30 months from integration by 6/100, 000 (SE = 3, P < 0.02) and was associated with the number of new patients with HIV on treatment at the clinics. Our findings suggest that during the implementation of integrated HIV care into PHC clinics, care for hypertensive patients could be compromised. Further research is needed to understand determinants of NCD care in South Africa and other high HIV-burdened settings to ensure patient-centered PHC.

  10. Deregulation of sale of over-the-counter drugs outside of pharmacies in the Republic of Korea: interrupted-time-series analysis of outpatient visits before and after the policy.

    Science.gov (United States)

    Chun, Sung-Youn; Park, Hye-Ki; Han, Kyu-Tae; Kim, Woorim; Lee, Hyo-Jung; Park, Eun-Cheol

    2017-07-12

    We evaluated the effectiveness of a policy allowing for the sale of over-the-counter drugs outside of pharmacies by examining its effect on number of monthly outpatient visits for acute upper respiratory infections, dyspepsia, and migraine. We used medical claims data extracted from the Korean National Health Insurance Cohort Database from 2009 to 2013. The Korean National Health Insurance Cohort Database comprises a nationally representative sample of claims - about 2% of the entire population - obtained from the medical record data held by the Korean National Health Insurance Corporation (which has data on the entire nation). The analysis included26,284,706 person-months of 1,042,728 individuals. An interrupted-time series analysis was performed. Outcome measures were monthly outpatient visits for acute upper respiratory infections, dyspepsia, and migraine. To investigate the effect of the policy, we compared the number of monthly visits before and after the policy's implementation in 2012. For acute upper respiratory infections, monthly outpatient visits showed a decreasing trend before the policy (ß = -0.0003);after it, a prompt change and increasing trend in monthly outpatient visits were observed, but these were non-significant. For dyspepsia, the trend was increasing before implementation (ß = -0.0101), but this reversed after implementation(ß = -0.007). For migraine, an increasing trend was observed before the policy (ß = 0.0057). After it, we observed a significant prompt change (ß = -0.0314) but no significant trend. Deregulation of selling over-the-counter medication outside of pharmacies reduced monthly outpatient visits for dyspepsia and migraine symptoms, but not acute upper respiratory infections.

  11. Time dependent policy-based access control

    DEFF Research Database (Denmark)

    Vasilikos, Panagiotis; Nielson, Flemming; Nielson, Hanne Riis

    2017-01-01

    also on other attributes of the environment such as the time. In this paper, we use systems of Timed Automata to model distributed systems and we present a logic in which one can express time-dependent policies for access control. We show how a fragment of our logic can be reduced to a logic......Access control policies are essential to determine who is allowed to access data in a system without compromising the data's security. However, applications inside a distributed environment may require those policies to be dependent on the actual content of the data, the flow of information, while...... that current model checkers for Timed Automata such as UPPAAL can handle and we present a translator that performs this reduction. We then use our translator and UPPAAL to enforce time-dependent policy-based access control on an example application from the aerospace industry....

  12. Time-optimal control of reactor power

    International Nuclear Information System (INIS)

    Bernard, J.A.

    1987-01-01

    Control laws that permit adjustments in reactor power to be made in minimum time and without overshoot have been formulated and demonstrated. These control laws which are derived from the standard and alternate dynamic period equations, are closed-form expressions of general applicability. These laws were deduced by noting that if a system is subject to one or more operating constraints, then the time-optimal response is to move the system along these constraints. Given that nuclear reactors are subject to limitations on the allowed reactor period, a time-optimal control law would step the period from infinity to the minimum allowed value, hold the period at that value for the duration of the transient, and then step the period back to infinity. The change in reactor would therefore be accomplished in minimum time. The resulting control laws are superior to other forms of time-optimal control because they are general-purpose, closed-form expressions that are both mathematically tractable and readily implanted. Moreover, these laws include provisions for the use of feedback. The results of simulation studies and actual experiments on the 5 MWt MIT Research Reactor in which these time-optimal control laws were used successfully to adjust the reactor power are presented

  13. Robust Control Charts for Time Series Data

    NARCIS (Netherlands)

    Croux, C.; Gelper, S.; Mahieu, K.

    2010-01-01

    This article presents a control chart for time series data, based on the one-step- ahead forecast errors of the Holt-Winters forecasting method. We use robust techniques to prevent that outliers affect the estimation of the control limits of the chart. Moreover, robustness is important to maintain

  14. Period of an Interrupted Pendulum

    Science.gov (United States)

    Miller, Bradley E.

    2002-11-01

    While demonstrating a classic conservation-of-energy problem to my AP Physics students, I became curious about the periodic motion that ensued for certain initial conditions. The original problem consists of releasing a mass at the end of a string from an initial position horizontal to the plane of a table. The string comes in contact with a peg some distance below the point where the string is attached at the top. One is asked to find what minimum fraction of the string's length should the peg be placed to have the mass complete a circle about the peg. However, when the mass is released from much lower heights, the system undergoes periodic motion that can be thought of as an interrupted pendulum.

  15. Real-time controller for hydrostatic transmission

    OpenAIRE

    2014-01-01

    M. Ing. (Electrical and Electronic Engineering) This dissertation describes the development of a modular real-time controller implemented on a personal computer for a hydrostatically driven vehicle. In such a vehicle the conventional mechanical transmission is replaced with a hydrostatic pump and two hydrostatic motors, making use of the secondary control principle. The infinitely variable transmission and wheel pair controller gives the vehicle superior traction and mobility over conventi...

  16. Interruptions in emergency medicine: things are not always what they seem.

    Science.gov (United States)

    Walter, Scott R

    2018-06-20

    We have all felt the cognitive disjuncture of being interrupted during an important task. Most ED physicians will readily proffer the high frequency and/or burden of interruptions during their work, and of the many observational studies of interruptions in healthcare EDs do indeed have high interruption rates[2]. In experimental psychology, where many of these ideas originated, there is plenty of evidence that interruptions negatively affect performance. Interruptions have been associated with reduced performance on complex tasks[3,4], increased sequence errors[5], increased task completion time and augmented annoyance and anxiety[6]. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Executing application function calls in response to an interrupt

    Science.gov (United States)

    Almasi, Gheorghe; Archer, Charles J.; Giampapa, Mark E.; Gooding, Thomas M.; Heidelberger, Philip; Parker, Jeffrey J.

    2010-05-11

    Executing application function calls in response to an interrupt including creating a thread; receiving an interrupt having an interrupt type; determining whether a value of a semaphore represents that interrupts are disabled; if the value of the semaphore represents that interrupts are not disabled: calling, by the thread, one or more preconfigured functions in dependence upon the interrupt type of the interrupt; yielding the thread; and if the value of the semaphore represents that interrupts are disabled: setting the value of the semaphore to represent to a kernel that interrupts are hard-disabled; and hard-disabling interrupts at the kernel.

  18. 30 CFR 18.48 - Circuit-interrupting devices.

    Science.gov (United States)

    2010-07-01

    ... energized. (f) Belt conveyors shall be equipped with control switches to automatically stop the driving motor in the event the belt is stopped, or abnormally slowed down. Note: Short transfer-type conveyors... Design Requirements § 18.48 Circuit-interrupting devices. (a) Each machine shall be equipped with a...

  19. HVDC interrupter experiments for large Magnetic Energy Transfer and Storage (METS) systems

    International Nuclear Information System (INIS)

    Swannack, C.E.; Haarman, R.A.; Lindsay, J.D.G.; Weldon, D.M.

    1975-01-01

    Proposed fusion-test reactors will require energy storage systems of hundreds of megajoules with transfer times of the order of one millisecond. The size of the energy storage submodule (and hence, the overall system cost and complexity) is directly determined by the voltage and current limits of the switch used for the energy transfer. Experiments are being conducted on high voltage dc circuit breakers as a major part of the energy storage, pulsed power program. DC circuit interruption characteristics of a commercially available ac power vacuum interrupter are discussed. Preliminary data of interruption characteristics are reported for an interrupter developed specifically to match a present METS circuit requirement

  20. A Wrist-Worn Thermohaptic Device for Graceful Interruption

    DEFF Research Database (Denmark)

    Bolton, Frank; Jalaliniya, Shahram; Pederson, Thomas

    2015-01-01

    Thermal haptics is a potential system output modality for wearable devices that promises to function at the periphery of human attention. When adequately combined with existing attention-governing mechanisms of the human mind, it could be used for interrupting the human agent at a time when......-worn thermohaptic actuator for self-mitigating interruption. We then develop a prototype and perform an insightful pilot study. We frame our empirical thermohaptic experimental work in terms of Peripheral Interaction concepts and show how this new approach to Human-Computer Interaction relates to the Context...

  1. Timing control by redundant inhibitory neuronal circuits

    Energy Technology Data Exchange (ETDEWEB)

    Tristan, I., E-mail: itristan@ucsd.edu; Rulkov, N. F.; Huerta, R.; Rabinovich, M. [BioCircuits Institute, University of California, San Diego, La Jolla, California 92093-0402 (United States)

    2014-03-15

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.

  2. Timing control by redundant inhibitory neuronal circuits

    International Nuclear Information System (INIS)

    Tristan, I.; Rulkov, N. F.; Huerta, R.; Rabinovich, M.

    2014-01-01

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model

  3. Timing system control software in the SLC

    International Nuclear Information System (INIS)

    Thompson, K.; Phinney, N.

    1985-04-01

    A new timing system that allows precision (approx.1 to 2 ns) control of the trigger times of klystrons, beam position monitors, and other devices on a pulse-to-pulse basis at up to 360 Hz is in operation in the first third of the SLAC linear accelerator. The control software is divided between a central host VAX and local Intel 8086-based microprocessor clusters. Facilities exist to set up and adjust the timing of devices or groups of devices independently for beam pulses having different destinations and purposes, which are run in an interlaced fashion during normal machine operation. Upgrading of the system is currently underway, using a new version of the Programmable Delay Unit CAMAC module to allow pipelining of timing information for three machine pulses. An overview of the current state of the system is presented in this paper, with an emphasis on software control

  4. A work observation study of nuclear medicine technologists: interruptions, resilience and implications for patient safety.

    Science.gov (United States)

    Larcos, George; Prgomet, Mirela; Georgiou, Andrew; Westbrook, Johanna

    2017-06-01

    Errors by nuclear medicine technologists during the preparation of radiopharmaceuticals or at other times can cause patient harm and may reflect the impact of interruptions, busy work environments and deficient systems or processes. We aimed to: (a) characterise the rate and nature of interruptions technologists experience and (b) identify strategies that support safety. We performed 100 hours of observation of 11 technologists at a major public hospital and measured the proportions of time spent in eight categories of work tasks, location of task, interruption rate and type and multitasking (tasks conducted in parallel). We catalogued specific safety-oriented strategies used by technologists. Technologists completed 5227 tasks and experienced 569 interruptions (mean, 4.5 times per hour; 95% CI 4.1 to 4.9). The highest interruption rate occurred when technologists were in transit between rooms (10.3 per hour (95% CI 8.3 to 12.5)). Interruptions during radiopharmaceutical preparation occurred a mean of 4.4 times per hour (95% CI 3.3 to 5.6). Most (n=426) tasks were interrupted once only and all tasks were resumed after interruption. Multitasking occurred 16.6% of the time. At least some interruptions were initiated by other technologists to convey important information and/or to render assistance. Technologists employed a variety of verbal and non-verbal strategies in all work areas (notably in the hot-lab) to minimise the impact of interruptions and optimise the safe conduct of procedures. Although most were due to individual choices, some strategies reflected overt or subliminal departmental policy. Some interruptions appear beneficial. Technologists' self-initiated strategies to support safe work practices appear to be an important element in supporting a resilient work environment in nuclear medicine. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. Piped water supply interruptions and acute diarrhea among under-five children in Addis Ababa slums, Ethiopia: A matched case-control study.

    Science.gov (United States)

    Adane, Metadel; Mengistie, Bezatu; Medhin, Girmay; Kloos, Helmut; Mulat, Worku

    2017-01-01

    The problem of intermittent piped water supplies that exists in low- and middle-income countries is particularly severe in the slums of sub-Saharan Africa. However, little is known about whether there is deterioration of the microbiological quality of the intermittent piped water supply at a household level and whether it is a factor in reducing or increasing the occurrence of acute diarrhea among under-five children in slums of Addis Ababa. This study aimed to determine the association of intermittent piped water supplies and point-of-use (POU) contamination of household stored water by Escherichia coli (E. coli) with acute diarrhea among under-five children in slums of Addis Ababa. A community-based matched case-control study was conducted from November to December, 2014. Cases were defined as under-five children with acute diarrhea during the two weeks before the survey. Controls were matched by age and neighborhood with cases by individual matching. Data were collected using a pre-tested structured questionnaire and E. coli analysis of water from piped water supplies and household stored water. A five-tube method of Most Probable Number (MPN)/100 ml standard procedure was used for E. coli analysis. Multivariable conditional logistic regression with 95% confidence interval (CI) was used for data analysis by controlling potential confounding effects of selected socio-demographic characteristics. During the two weeks before the survey, 87.9% of case households and 51.0% of control households had an intermittent piped water supply for an average of 4.3 days and 3.9 days, respectively. POU contamination of household stored water by E. coli was found in 83.3% of the case households, and 52.1% of the control households. In a fully adjusted model, a periodically intermittent piped water supply (adjusted matched odds ratio (adjusted mOR) = 4.8; 95% CI: 1.3-17.8), POU water contamination in household stored water by E. coli (adjusted mOR = 3.3; 95% CI: 1.1-10.1), water

  6. Time Optimal Run-time Evaluation of Distributed Timing Constraints in Process Control Software

    DEFF Research Database (Denmark)

    Drejer, N.; Kristensen, C.H.

    1993-01-01

    This paper considers run-time evaluation of an important class of constraints; Timing constraints. These appear extensively in process control systems. Timing constraints are considered in distributed systems, i.e. systems consisting of multiple autonomous nodes......

  7. Real-time measurement and control at Jet. Experiment Control

    International Nuclear Information System (INIS)

    Felton, R.; Zabeo, L.; Sartori, F.; Piccolo, F.; Farthing, J.; Budd, T.; Dorling, S.; McCullen, P.; Harling, J.; Dalley, S.; Goodyear, A.; Stephen, A.; Card, P.; Bright, M.; Lucock, R.; Jones, E.; Griph, S.; Hogben, C.; Beldishevski, M.; Buckley, M.; Davis, J.; Young, I.; Hemming, O.; Wheatley, M.; Heesterman, P.; Lloyd, G.; Walters, M.; Bridge, R.; Leggate, H.; Howell, D.; Zastrow, K.D.; Giroud, C.; Coffey, I.; Hawkes, N.; Stamp, M.; Barnsley, R.; Edlington, T.; Guenther, K.; Gowers, C.; Popovichef, S.; Huber, A.; Ingesson, C.; Joffrin, E.; Mazon, D.; Moreau, D.; Murari, A.; Riva, M.; Barana, O.; Bolzonella, T.; Valisa, M.; Innocente, P.; Zerbini, M.; Bosak, K.; Blum, J.; Vitale, E.; Crisanti, F.; La Luna, E. de; Sanchez, J.

    2004-01-01

    Over the past few ears, the preparation of ITER-relevant plasma scenarios has been the main focus experimental activity on tokamaks. The development of integrated, simultaneous, real-time controls of plasma shape, current, pressure, temperature, radiation, neutron profiles, and also impurities, ELMs (edge localized modes) and MHD are now seen to be essential for further development of quasi-steady state conditions with feedback, or the stabilisation of transient phenomena with event-driven actions. For this thrust, the EFDA JET Real Time Project has developed a set of real-time plasma measurements, experiment control, and communication facilities. The Plasma Diagnostics used for real-time experiments are Far Infra Red interferometry, polarimetry, visible, UV and X-ray spectroscopy, LIDAR, bolometry, neutron and magnetics. Further analysis systems produce integrated results such as temperature profiles on geometry derived from MHD equilibrium solutions. The Actuators include toroidal, poloidal and divertor coils, gas and pellet fuelling, neutral beam injection, radiofrequency (ICRH) waves and microwaves (LH). The Heating/Fuelling Operators can either define a power or gas request waveform or select the real-time instantaneous power/gas request from the Real Time Experiment Central Control (RTCC) system. The Real Time Experiment Control system provides both a high-level, control-programming environment and interlocks with the actuators. A MATLAB facility is being developed for the development of more complex controllers. The plasma measurement, controller and plant control systems communicate in ATM network. The EFDA Real Time project is essential groundwork for future reactors such as ITER. It involves many staff from several institutions. The facility is now frequently used in experiments. (authors)

  8. Processing implicit control: evidence from reading times

    Directory of Open Access Journals (Sweden)

    Michael eMcCourt

    2015-10-01

    Full Text Available Sentences such as The ship was sunk to collect the insurance exhibit an unusual form of anaphora, implicit control, where neither anaphor nor antecedent is audible. The nonfinite reason clause has an understood subject, PRO, that is anaphoric; here it may be understood as naming the agent of the event of the host clause. Yet since the host is a short passive, this agent is realized by no audible dependent. The putative antecedent to PRO is therefore implicit, which it normally cannot be. What sorts of representations subserve the comprehension of this dependency? Here we present four self-paced reading time studies directed at this question. Previous work showed no processing cost for implicit versus explicit control, and took this to support the view that PRO is linked syntactically to a silent argument in the passive. We challenge this conclusion by reporting that we also find no processing cost for remote implicit control, as in: The ship was sunk. The reason was to collect the insurance. Here the dependency crosses two independent sentences, and so cannot, we argue, be mediated by syntax. Our Experiments 1-4 examined the processing of both implicit (short passive and explicit (active or long passive control in both local and remote configurations. Experiments 3 and 4 added either three days ago or just in order to the local conditions, to control for the distance between the passive and infinitival verbs, and for the predictability of the reason clause, respectively. We replicate the finding that implicit control does not impose an additional processing cost. But critically we show that remote control does not impose a processing cost either. Reading times at the reason clause were never slower when control was remote. In fact they were always faster. Thus efficient processing of local implicit control cannot show that implicit control is mediated by syntax; nor, in turn, that there is a silent but grammatically active argument in passives.

  9. Virological failure of staggered and simultaneous treatment interruption in HIV patients who began Efavirenz-based regimens after allergic reactions to nevirapine

    Directory of Open Access Journals (Sweden)

    Siripassorn Krittaecho

    2013-01-01

    Full Text Available Abstract Objective The objective of this work was to study the virological outcomes associated with two different types of treatment interruption strategies in patients with allergic reactions to nevirapine (NVP. We compared the virological outcomes of (1 HIV-1-infected patients who discontinued an initial NVP-based regimen because of cutaneous allergic reactions to NVP; different types of interruption strategies were used, and second-line regimen was based on efavirenz (EFV; and (2 HIV-1-infected patients who began an EFV-based regimen as a first-line therapy (controls. Methods This retrospective cohort included patients who began an EFV-based regimen, between January 2002 and December 2008, as either an initial regimen or as a subsequent regimen after resolving a cutaneous allergic reaction against an initial NVP-based regimen. The study ended in March 2010. The primary outcome was virological failure, which was defined as either (a two consecutive plasma HIV-1 RNA levels >400 copies/mL or (b a plasma HIV-1 RNA level >1,000 copies/mL plus any genotypic resistance mutation. Results A total of 559 patients were stratified into three groups: (a Simultaneous Interruption, in which the subjects simultaneously discontinued all the drugs in an NVP-based regimen following an allergic reaction (n=161; (b Staggered Interruption, in which the subjects discontinued NVP treatment while continuing nucleoside reverse transcriptase inhibitor (NRTI backbone therapy for a median of 7 days (n=82; and (c Control, in which the subjects were naïve to antiretroviral therapy (n=316. The overall median follow-up time was 43 months. Incidence of virological failure in Simultaneous Interruption was 12.9 cases per 1,000 person-years, which trended toward being higher than the incidences in Staggered Interruption (5.4 and Control (6.6. However, differences were not statistically significant. Conclusions Among the patients who had an acute allergic reaction to first

  10. Change in non-alcoholic beverage sales following a 10-pence levy on sugar-sweetened beverages within a national chain of restaurants in the UK: interrupted time series analysis of a natural experiment.

    Science.gov (United States)

    Cornelsen, Laura; Mytton, Oliver T; Adams, Jean; Gasparrini, Antonio; Iskander, Dalia; Knai, Cecile; Petticrew, Mark; Scott, Courtney; Smith, Richard; Thompson, Claire; White, Martin; Cummins, Steven

    2017-11-01

    This study evaluates changes in sales of non-alcoholic beverages in Jamie's Italian, a national chain of commercial restaurants in the UK, following the introduction of a £0.10 per-beverage levy on sugar-sweetened beverages (SSBs) and supporting activity including beverage menu redesign, new products and establishment of a children's health fund from levy proceeds. We used an interrupted time series design to quantify changes in sales of non-alcoholic beverages 12 weeks and 6 months after implementation of the levy, using itemised electronic point of sale data. Main outcomes were number of SSBs and other non-alcoholic beverages sold per customer. Linear regression and multilevel random effects models, adjusting for seasonality and clustering, were used to investigate changes in SSB sales across all restaurants (n=37) and by tertiles of baseline restaurant SSB sales per customer. Compared with the prelevy period, the number of SSBs sold per customer declined by 11.0% (-17.3% to -4.3%) at 12 weeks and 9.3% (-15.2% to -3.2%) at 6 months. For non-levied beverages, sales per customer of children's fruit juice declined by 34.7% (-55.3% to -4.3%) at 12 weeks and 9.9% (-16.8% to -2.4%) at 6 months. At 6 months, sales per customer of fruit juice increased by 21.8% (14.0% to 30.2%) but sales of diet cola (-7.3%; -11.7% to -2.8%) and bottled waters (-6.5%; -11.0% to -1.7%) declined. Changes in sales were only observed in restaurants in the medium and high tertiles of baseline SSB sales per customer. Introduction of a £0.10 levy on SSBs alongside complementary activities is associated with declines in SSB sales per customer in the short and medium term, particularly in restaurants with higher baseline sales of SSBs. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Short-term and sustained effects of a health system strengthening intervention to improve mortality trends for paediatric severe malnutrition in rural South African hospitals: An interrupted time series design

    Directory of Open Access Journals (Sweden)

    M Muzigaba

    2017-04-01

    Full Text Available Background. Case fatality rates for childhood severe acute malnutrition (SAM remain high in some resource-limited facilities in South Africa (SA, despite the widespread availability of the World Health Organization treatment guidelines. There is a need to develop reproducible interventions that reinforce the implementation of these guidelines and assess their effect and sustainability. Objectives. To assess the short-term and sustained effects of a health system strengthening intervention on mortality attributable to SAM in two hospitals located in the Eastern Cape Province of SA. Methods. This was a theory-driven evaluation conducted in two rural hospitals in SA over a 69-month period (2009 - 2014. In both facilities, a health system strengthening intervention was implemented within the first 32 months, and thereafter discontinued. Sixty-nine monthly data series were collected on: (i monthly total SAM case fatality rate (CFR; (ii monthly SAM CFR within 24 hours of admission; and (iii monthly SAM CFR among HIV-positive cases, to determine the intervention’s effect within the first 32 months and sustainability over the remaining 37 months. The data were analysed using Linden’s method for analysing interrupted time series data. Results. The study revealed that the intervention was associated with a statistically significant decrease of up to 0.4% in monthly total SAM CFR, a non-statistically significant decrease of up to 0.09% in monthly SAM CFR within 24 hours of admission and a non-statistically significant decrease of up to 0.11% in monthly SAM CFR among HIV-positive cases. The decrease in mortality trends for both outcomes was only slightly reversed upon the discontinuation of the intervention. No autocorrelation was detected in the regression models generated during data analyses. Conclusion. The study findings suggest that although the intervention was designed to be self-sustaining, this may not have been the case. A qualitative enquiry

  12. Interrupted or continuous-intradermal suturing? Statistical analysis of postoperative scars

    Directory of Open Access Journals (Sweden)

    Elif Sarı

    2014-12-01

    Full Text Available Background and Design: Postoperative scar development is an important problem for patients treated in plastic surgery clinics. Most patients think that continuous intradermal suturing is superior to interrupted suturing because they assume that it creates less scarring. We evaluated scars that form following intradermal and interrupted suturing. This article presents our controlled study that objectively compared the scars on patients' faces using a wound evaluation scale. Materials and Methods: Thirty-five patients, who had undergone operations on the bilateral cheeks, were included in this study. Thirty patients were female; five patients were male. Their mean age was 40.05 years. The average scar evaluation time after surgery was 9.05 months. Elliptical excisions were made on the lesions under local anesthesia. The incisions on the right cheeks were sutured with 6/0 monofilament nonabsorbable sutures using the continuous intradermal suturing technique. The left cheek incisions were sutured with same sutures using the interrupted suturing method. Results: The patients were evaluated 7–11 months after operation (mean: 9.05 months using the Stony Brook Scar Evaluation Scale. A Related Samples T-test was used for statistical evaluation of the differences between the suturing techniques. No significant differences were noted in scar formation between the two suturing methods (p>0.05. Conclusion: We found no differences in scar formation between the two frequently used suturing techniques studied here. We believe that the suturing technique is a less important determinant of scar formation than are other factors.

  13. COMPARATIVE STUDY OF RTOS AND PRIMITIVE INTERRUPT IN EMBEDDED SYSTEM

    Directory of Open Access Journals (Sweden)

    Dwi Purnomo

    2015-03-01

    Full Text Available Multitasking is one of the most challenging issues in the automation industry which is highly depended on the embedded system. There are two methods to perform multitasking in embedded system: RTOS and primitive interrupt. The main purpose of this research is to compare the performance of R¬TOS with primitive method while concurrently undertaking multiple tasks. The system, which is able to perform various tasks, has been built to evaluate the performance of both methods. There are four tasks introduced in the system: servo task, sensor task, LED task, and LCD task. The performance of each method is indicated by the success rate of the sensor task detection. Sensor task detection will be compared with the true value which is calculated and measured manually during observation time. Observation time was varied after several iterations and the data of the iteration are recorded for both RTOS and primitive interrupt methods. The results of the conducted experiments have shown that, RTOS is more accurate than interrupt method. However, the data variance of the primitive interrupt method is narrower than RTOS. Therefore, to choose a better method, an optimization is needed to be done and each product has its own standard.

  14. Deformation of contact surfaces in a vacuum interrupter after high-current interruptions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haoran; Wang, Zhenxing, E-mail: zxwang@xjtu.edu.cn; Zhou, Zhipeng; Jiang, Yanjun; Wang, Jianhua; Geng, Yingsan; Liu, Zhiyuan [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2016-08-07

    In a high-current interruption, the contact surface in a vacuum interrupter might be severely damaged by constricted vacuum arcs causing a molten area on it. As a result, a protrusion will be initiated by a transient recovery voltage after current zero, enhancing the local electric field and making breakdowns occur easier. The objective of this paper is to simulate the deformation process on the molten area under a high electric field by adopting the finite element method. A time-dependent Electrohydrodynamic model was established, and the liquid-gas interface was tracked by the level-set method. From the results, the liquid metal can be deformed to a Taylor cone if the applied electric field is above a critical value. This value is correlated to the initial geometry of the liquid metal, which increases as the size of the liquid metal decreases. Moreover, the buildup time of a Taylor cone obeys the power law t = k × E{sup −3}, where E is the initial electric field and k is a coefficient related to the material property, indicating a temporal self-similar characteristic. In addition, the influence of temperature has little impact on the deformation but has great impact on electron emission. Finally, the possible reason to initiate a delayed breakdown is associated with the deformation. The breakdown does not occur immediately when the voltage is just applied upon the gap but is postponed to several milliseconds later when the tip is formed on the liquid metal.

  15. Optical Cutting Interruption Sensor for Fiber Lasers

    Directory of Open Access Journals (Sweden)

    Benedikt Adelmann

    2015-09-01

    Full Text Available We report on an optical sensor system attached to a 4 kW fiber laser cutting machine to detect cutting interruptions. The sensor records the thermal radiation from the process zone with a modified ring mirror and optical filter arrangement, which is placed between the cutting head and the collimator. The process radiation is sensed by a Si and InGaAs diode combination with the detected signals being digitalized with 20 kHz. To demonstrate the function of the sensor, signals arising during fusion cutting of 1 mm stainless steel and mild steel with and without cutting interruptions are evaluated and typical signatures derived. In the recorded signals the piercing process, the laser switch on and switch off point and waiting period are clearly resolved. To identify the cutting interruption, the signals of both Si and InGaAs diodes are high pass filtered and the signal fluctuation ranges being subsequently calculated. Introducing a correction factor, we identify that only in case of a cutting interruption the fluctuation range of the Si diode exceeds the InGaAs diode. This characteristic signature was successfully used to detect 80 cutting interruptions of 83 incomplete cuts (alpha error 3.6% and system recorded no cutting interruption from 110 faultless cuts (beta error of 0. This particularly high detection rate in combination with the easy integration of the sensor, highlight its potential for cutting interruption detection in industrial applications.

  16. PEP-II injection timing and controls

    International Nuclear Information System (INIS)

    Bharadwaj, V.; Browne, M.; Crane, M.; Gromme, T.; Himel, T.; Ross, M.; Stanek, M.; Ronan, M.

    1997-07-01

    Hardware has been built and software written and incorporated in the existing SLC accelerator control system to control injection of beam pulses from the accelerator into the PEP-II storage rings currently under construction. Hardware includes a CAMAC module to delay the machine timing fiducial in order that a beam pulse extracted from a damping ring will be injected into a selected group of four 476 MHz buckets in a PEP-II ring. Further timing control is accomplished by shifting the phase of the bunches stored in the damping rings before extraction while leaving the phase of the PEP-II stored beam unchanged. The software which drives timing devices on a pulse-to-pulse basis relies on a dedicated communication link on which one scheduling microprocessor broadcasts a 128-bit message to all distributed control microprocessors at 360 Hz. PEP-II injection will be driven by the scheduling microprocessor according to lists specifying bucket numbers in arbitrary order, and according to scheduling constraints maximizing the useful beam delivered to the SLC collider currently in operation. These lists will be generated by a microprocessor monitoring the current stored per bucket in each of the PEP-II rings

  17. Driven to distraction: The nature and apparent purpose of interruptions in critical care and implications for HIT.

    Science.gov (United States)

    Mamykina, Lena; Carter, Eileen J; Sheehan, Barbara; Stanley Hum, R; Twohig, Bridget C; Kaufman, David R

    2017-05-01

    To examine the apparent purpose of interruptions in a Pediatric Intensive Care Unit and opportunities to reduce their burden with informatics solutions. In this prospective observational study, researchers shadowed clinicians in the unit for one hour at a time, recording all interruptions participating clinicians experienced or initiated, their starting time, duration, and a short description that could help to infer their apparent purpose. All captured interruptions were classified inductively on their source and apparent purpose and on the optimal representational media for fulfilling their apparent purpose. The researchers observed thirty-four one-hour sessions with clinicians in the unit, including 21 nurses and 13 residents and house physicians. The physicians were interrupted on average 11.9 times per hour and interrupted others 8.8 times per hour. Nurses were interrupted 8.6 times per hour and interrupted others 5.1 times per hour. The apparent purpose of interruptions included Information Seeking and Sharing (n=259, 46.3%), Directives and Requests (n=70, 12%), Shared Decision-Making (n=49, 8.8%), Direct Patient Care (n=36, 6.4%), Social (n=71, 12.7%), Device Alarms (n=28, 5%), and Non-Clinical (n=10, 1.8%); 6.6% were not classified due to insufficient description. Of all captured interruptions, 29.5% were classified as being better served with informational displays or computer-mediated communication. Deeper understanding of the purpose of interruptions in critical care can help to distinguish between interruptions that require face-to-face conversation and those that can be eliminated with informatics solutions. The proposed taxonomy of interruptions and representational analysis can be used to further advance the science of interruptions in clinical care. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Real time computer controlled weld skate

    Science.gov (United States)

    Wall, W. A., Jr.

    1977-01-01

    A real time, adaptive control, automatic welding system was developed. This system utilizes the general case geometrical relationships between a weldment and a weld skate to precisely maintain constant weld speed and torch angle along a contoured workplace. The system is compatible with the gas tungsten arc weld process or can be adapted to other weld processes. Heli-arc cutting and machine tool routing operations are possible applications.

  19. Optimal, real-time control--colliders

    International Nuclear Information System (INIS)

    Spencer, J.E.

    1991-05-01

    With reasonable definitions, optimal control is possible for both classical and quantal systems with new approaches called PISC(Parallel) and NISC(Neural) from analogy with RISC (Reduced Instruction Set Computing). If control equals interaction, observation and comparison to some figure of merit with interaction via external fields, then optimization comes from varying these fields to give design or operating goals. Structural stability can then give us tolerance and design constraints. But simulations use simplified models, are not in real-time and assume fixed or stationary conditions, so optimal control goes far beyond convergence rates of algorithms. It is inseparable from design and this has many implications for colliders. 12 refs., 3 figs

  20. The Effect of Integration of Self-Management Web Platforms on Health Status in Chronic Obstructive Pulmonary Disease Management in Primary Care (e-Vita Study): Interrupted Time Series Design.

    Science.gov (United States)

    Talboom-Kamp, Esther Pwa; Verdijk, Noortje A; Kasteleyn, Marise J; Harmans, Lara M; Talboom, Irvin Jsh; Looijmans-van den Akker, Ingrid; van Geloven, Nan; Numans, Mattijs E; Chavannes, Niels H

    2017-08-16

    Worldwide nearly 3 million people die from chronic obstructive pulmonary disease (COPD) every year. Integrated disease management (IDM) improves quality of life for COPD patients and can reduce hospitalization. Self-management of COPD through eHealth is an effective method to improve IDM and clinical outcomes. The objective of this implementation study was to investigate the effect of 3 chronic obstructive pulmonary disease eHealth programs applied in primary care on health status. The e-Vita COPD study compares different levels of integration of Web-based self-management platforms in IDM in 3 primary care settings. Patient health status is examined using the Clinical COPD Questionnaire (CCQ). The parallel cohort design includes 3 levels of integration in IDM (groups 1, 2, 3) and randomization of 2 levels of personal assistance for patients (group A, high assistance, group B, low assistance). Interrupted time series (ITS) design was used to collect CCQ data at multiple time points before and after intervention, and multilevel linear regression modeling was used to analyze CCQ data. Of the 702 invited patients, 215 (30.6%) registered to a platform. Of these, 82 participated in group 1 (high integration IDM), 36 in group 1A (high assistance), and 46 in group 1B (low assistance); 96 participated in group 2 (medium integration IDM), 44 in group 2A (high assistance) and 52 in group 2B (low assistance); also, 37 participated in group 3 (no integration IDM). In the total group, no significant difference was found in change in CCQ trend (P=.334) before (-0.47% per month) and after the intervention (-0.084% per month). Also, no significant difference was found in CCQ changes before versus after the intervention between the groups with high versus low personal assistance. In all subgroups, there was no significant change in the CCQ trend before and after the intervention (group 1A, P=.237; 1B, P=.991; 2A, P=.120; 2B, P=.166; 3, P=.945). The e-Vita eHealth-supported COPD

  1. A Multiple-Reception Access Protocol with Interruptions with Mixed Priorities in CDMA Networks

    Institute of Scientific and Technical Information of China (English)

    Lu Xiaowen; Zhu Jinkang

    2003-01-01

    A novel access protocol called Multiple-Reception Access Protocol (MRAP) and its modification MRAP/WI are proposed. In this protocol, all colliding users with a common code can be identified by the base station due to the offset of arrival time Thus they can retransmit access requests under the base station's control. Furthermore new arrivals with higher priority level can interrupt the lower retransmission in order to reduce its access delay although it increases the lower priority's delay. Simulation results of MRAP and MRAP/WI are given in order to highlight the superior performance of the proposed approach.

  2. Time under control: time perspective and desire for control in substance use.

    Science.gov (United States)

    Fieulaine, Nicolas; Martinez, Frederic

    2010-08-01

    To investigate the role of time perspective and desire for control in self-reported substance use and to test for a moderating effect of desire for control in the relation between time perspective and substance use. A random sample of 240 persons, aged 15 years and over, selected in various public spaces in an urban region in central France. Time perspective was measured using subscales of the Zimbardo Time Perspective Inventory (ZTPI, Zimbardo & Boyd, 1999), Desire for control was measured using a translated version of the Desire for Control Scale (DCS, Burger & Cooper, 1979), and substance use was self-reported. After controlling for age and gender, significant links were found between time perspective and substance use. Desire for control did not appear to be directly related to substance use. The interaction effect between TP and desire for control appeared to be related to substance use. There was evidence that the relation between TP and substance use is buffered by low desire for control. This study converges with previous studies demonstrating the relation between TP and substance use, but provides evidence of the moderating role played by desire for control. Desire for control thus appears as worthy of interest in the analysis of self-regulatory process, and further research on the links between TP and various aspects of control is required. In order to be more effective, the design of future studies and interventions based on time-related issues should consider how desire for control plays a part in establishing vulnerability profiles. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. The Effects of Interruption Task Complexity and Interruptions on Student Multitasking

    OpenAIRE

    Tan, Jiun Yi

    2013-01-01

    Students commonly multitask while studying. The ubiquitous use of laptops and computers has facilitated this phenomenon and even changed the nature of multitasking in studying environments. Interruptions have an undeniable presence in these everyday studying environments and there are growing concerns about their potential to disrupt both performance and the learning process. Since interruptions are unavoidable, it is useful to identify the features that make some interruptions more disruptiv...

  4. Experiments with vacuum interrupters used for large dc-current interruption

    International Nuclear Information System (INIS)

    Warren, R.W.

    1977-10-01

    Vacuum interrupters have been tested in circuits similar to those used in theta-pinch and Tokamak fusion devices. The effects on performance of auxiliary circuit components and axial magnetic fields have been determined, and limits to lifetime caused by mechanical and electrical wear have been measured. Results show that the upper reliable limit of interruption is independent of the auxiliary components but quite dependent on interrupter size and on the axial field

  5. Flowering time control in European winter wheat

    Directory of Open Access Journals (Sweden)

    Simon Martin Langer

    2014-10-01

    Full Text Available Flowering time is an important trait in wheat breeding as it affects adaptation and yield potential. The aim of this study was to investigate the genetic architecture of flowering time in European winter bread wheat cultivars. To this end a population of 410 winter wheat varieties was evaluated in multi-location field trials and genotyped by a genotyping-by-sequencing approach and candidate gene markers. Our analyses revealed that the photoperiod regulator Ppd-D1 is the major factor affecting flowering time in this germplasm set, explaining 58% of the genotypic variance. Copy number variation at the Ppd-B1 locus was present but explains only 3.2% and thus a comparably small proportion of genotypic variance. By contrast, the plant height loci Rht-B1 and Rht-D1 had no effect on flowering time. The genome-wide scan identified six QTL which each explain only a small proportion of genotypic variance and in addition we identified a number of epistatic QTL, also with small effects. Taken together, our results show that flowering time in European winter bread wheat cultivars is mainly controlled by Ppd-D1 while the fine tuning to local climatic conditions is achieved through Ppd-B1 copy number variation and a larger number of QTL with small effects.

  6. Real-time control of fusion reactors

    International Nuclear Information System (INIS)

    Goncalves, B.; Sousa, J.; Varandas, C.A.F.

    2010-01-01

    The next generation fusion experiments, e.g. ITER, will be highly complex and raise new challenges in the field of control and data acquisition systems. The more advanced operation scenarios have to be capable of sustaining long pulse steady-state plasma and to suppress plasma instabilities almost completely. Such scenarios will heavily rely on Multiple-Input-Multiple-Output (MIMO) fast control systems. To ensure safety for the operation these systems have to be robust and resilient to faults while ensuring high availability. Mindful of the importance of such features for future fusion experiments ATCA based systems have been successfully used in fusion experiment as MIMO fast controller. This is the most promising architecture to substantially enhance the performance and capability of existing standard systems delivering well high throughput as well as high availability. The real-time control needs of a fusion experiment, the rational for the presently pursued solutions, the existing problems and the broad scientific and technical questions that need to be addressed on the path to a fusion power plant will be discussed.

  7. Anticipating Interruptions. Security and risk in a liberalized electricity infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Silvast, A.

    2013-11-01

    During the past ten years, a number of social scientists have emphasized the importance of material infrastructures like electricity supply as a research topic for the social sciences. The developing of such new perspectives concerning infrastructures also includes uncertainties and risks. This research analyzes the management of uncertainties in the Finnish electricity infrastructure by posing the following research question: how are electricity interruptions, or blackouts, anticipated in Finland and how are these interruptions managed as risks? The main research methodology of the work is multi-sited field work. The empirical materials include interviews with experts and lay people (33 interviews); participant observation in two electricity control rooms; an electricity consumer survey (115 respondents); and also a number of infrastructure and security policy documents and observations from electricity security seminars. The materials were primarily gathered between 2004 and 2008. Social science research often links risks with major current social changes or socio-cultural risk perceptions. In recent international social science discussions, however, a new research topic has emerged - those styles of reasoning and techniques of governance that are deployed to manage risk as a practical matter. My study explores these themes empirically by focusing on the specific habitual practices of risk management in the Finnish electricity infrastructure. The work develops various also semi-ethnographic inquiries into infrastructure risk techniques like monitor screening of real-time risks in electricity control rooms; the management of risks in a liberalized electricity market; the emergence of Finnish reasoning about blackouts from a specific historical background; and the ways in which electricity consumers respond to blackouts in their homes. In addition, the work reflects upon the position of a risk researcher in those situations when the research subjects do not define

  8. Real-time data acquisition and control system for the 349-pixel TACTIC atmospheric Cherenkov imaging telescope

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, K.K.; Koul, R.; Kanda, A.; Kaul, S.R.; Tickoo, A.K. E-mail: aktickoo@apsara.barc.ernet.in; Rannot, R.C.; Chandra, P.; Bhatt, N.; Chouhan, N.; Venugopal, K.; Kothari, M.; Goyal, H.C.; Dhar, V.K.; Kaul, S.K

    2004-07-21

    An interrupt-based multinode data acquisition and control system has been developed for the imaging element of the TACTIC {gamma}-ray telescope. The system which has been designed around a 3-node network of PCs running the QNX real-time operating system, provides single-point control with elaborate GUI facilities for operating the multi-pixel camera of the telescope. In addition to acquiring data from the 349-pixel photomultiplier tube based imaging camera in real time, the system also provides continuous monitoring and control of several vital parameters of the telescope for ensuring the quality of the data. The paper describes the salient features of the hardware and software of the data acquisition and control system of the telescope.

  9. Effectiveness of Cepharanthin in decreasing interruptions during radiation therapy for oral cancer

    International Nuclear Information System (INIS)

    Uchiyama, Yuka; Murakami, Shumei; Kamimoto, Naoya; Nakatani, Atsutoshi; Furukawa, Souhei

    2005-01-01

    The objectives of this study was to examine the effectiveness of Cepharanthin (Kakensyoyaku, Tokyo, Japan) at decreasing side effects during radiation therapy for oral cancer and thereby allowing the completion of radiation therapy without interruption. Two hundred fifteen patients diagnosed with oral cancers were assigned to either Cepharanthin or control groups and underwent external beam irradiation. The completion of the course of radiation therapy and the occurrence of side effects such as mucositis, dysgeusia, and xerostomia during the radiation therapy were evaluated and compared. The completion rate was 87.4% for the Cepharanthin group versus 67.0% for the control group, and the difference was statistically significant (P<0.01). Mucositis did not appear in 58 of 127 cases (45.7%) in the Cepharanthin group or in 21 of 88 cases (23.9%) in the control group. Mucositis developed in 24.6% of the Cepharanthin group and 53.7% of the control group within 2 weeks of irradiation. There were significant relationships between the use of Cepharanthin and the development and timing of mucositis (both P<0.01). Cepharanthin improved the completion of radiation therapy without interruption and reduced or delayed the development of mucositis during radiation therapy for oral cancer. (author)

  10. Interrupting behaviour: Minimizing decision costs via temporal commitment and low-level interrupts.

    Science.gov (United States)

    Lloyd, Kevin; Dayan, Peter

    2018-01-01

    Ideal decision-makers should constantly assess all sources of information about opportunities and threats, and be able to redetermine their choices promptly in the face of change. However, perpetual monitoring and reassessment impose inordinate sensing and computational costs, making them impractical for animals and machines alike. The obvious alternative of committing for extended periods of time to limited sensory strategies associated with particular courses of action can be dangerous and wasteful. Here, we explore the intermediate possibility of making provisional temporal commitments whilst admitting interruption based on limited broader observation. We simulate foraging under threat of predation to elucidate the benefits of such a scheme. We relate our results to diseases of distractibility and roving attention, and consider mechanistic substrates such as noradrenergic neuromodulation.

  11. Interrupting behaviour: Minimizing decision costs via temporal commitment and low-level interrupts.

    Directory of Open Access Journals (Sweden)

    Kevin Lloyd

    2018-01-01

    Full Text Available Ideal decision-makers should constantly assess all sources of information about opportunities and threats, and be able to redetermine their choices promptly in the face of change. However, perpetual monitoring and reassessment impose inordinate sensing and computational costs, making them impractical for animals and machines alike. The obvious alternative of committing for extended periods of time to limited sensory strategies associated with particular courses of action can be dangerous and wasteful. Here, we explore the intermediate possibility of making provisional temporal commitments whilst admitting interruption based on limited broader observation. We simulate foraging under threat of predation to elucidate the benefits of such a scheme. We relate our results to diseases of distractibility and roving attention, and consider mechanistic substrates such as noradrenergic neuromodulation.

  12. Interrupting behaviour: Minimizing decision costs via temporal commitment and low-level interrupts

    Science.gov (United States)

    Dayan, Peter

    2018-01-01

    Ideal decision-makers should constantly assess all sources of information about opportunities and threats, and be able to redetermine their choices promptly in the face of change. However, perpetual monitoring and reassessment impose inordinate sensing and computational costs, making them impractical for animals and machines alike. The obvious alternative of committing for extended periods of time to limited sensory strategies associated with particular courses of action can be dangerous and wasteful. Here, we explore the intermediate possibility of making provisional temporal commitments whilst admitting interruption based on limited broader observation. We simulate foraging under threat of predation to elucidate the benefits of such a scheme. We relate our results to diseases of distractibility and roving attention, and consider mechanistic substrates such as noradrenergic neuromodulation. PMID:29338004

  13. Short and long term variability of the interrupter technique under field and standardised conditions in 3-6 year old children

    NARCIS (Netherlands)

    Beelen, RMJ; Smit, HA; van Strien, RT; Koopman, LP; Brussee, JE; Brunekreef, B; Gerritsen, J; Merkus, PJFM

    2003-01-01

    Background: The short and long term variability of the interrupter technique was assessed to determine whether interrupter resistance is a stable individual characteristic over time. The effect of field and standardised measurement conditions on the within-subject variability of the interrupter

  14. From distributed to multicore architecture in the RFX-mod real time control system

    International Nuclear Information System (INIS)

    Manduchi, G.; Luchetta, A.; Soppelsa, A.; Taliercio, C.

    2014-01-01

    Highlights: • The paper describes the experience in running the real-time control system of RFX-mod. • It presents a new architecture based on multicore technology. • It analyze the feasibility of Linux MRG for real-time control. • It presents an application of the MARTe framework. - Abstract: The real-time control system of RFX has been operating since 2004 providing effective control of the plasma position and of the MagnetoHydroDynamic (MHD) modes. The demand for new and more computing-intensive control algorithms and the need for shorter latency pushed the system to its limits and, thus, a complete re-design was carried out in 2012. The new system adopts radically different solutions in hardware, operating system and software management. The VME PowerPC CPUs communicating over Ethernet have been now replaced by a single multicore server. VxWorks, previously used in the VME CPUs has now been replaced by Linux, which can be currently considered a real-time system provided an accurate tuning of the Linux scheduler and interrupt configuration. The previous framework for control and communication has been replaced by MARTe, a modern framework for real-time control gaining interest in the fusion community. The usage of MARTe allowed a rapid development of the control system and, in particular, its intrinsic simulation ability gave us the possibility of carrying out most debugging in simulation, without affecting machine operation. As a result the whole system has been finally commissioned in RFX in only two weeks

  15. From distributed to multicore architecture in the RFX-mod real time control system

    Energy Technology Data Exchange (ETDEWEB)

    Manduchi, G., E-mail: gabriele.manduchi@igi.cnr.it; Luchetta, A.; Soppelsa, A.; Taliercio, C.

    2014-03-15

    Highlights: • The paper describes the experience in running the real-time control system of RFX-mod. • It presents a new architecture based on multicore technology. • It analyze the feasibility of Linux MRG for real-time control. • It presents an application of the MARTe framework. - Abstract: The real-time control system of RFX has been operating since 2004 providing effective control of the plasma position and of the MagnetoHydroDynamic (MHD) modes. The demand for new and more computing-intensive control algorithms and the need for shorter latency pushed the system to its limits and, thus, a complete re-design was carried out in 2012. The new system adopts radically different solutions in hardware, operating system and software management. The VME PowerPC CPUs communicating over Ethernet have been now replaced by a single multicore server. VxWorks, previously used in the VME CPUs has now been replaced by Linux, which can be currently considered a real-time system provided an accurate tuning of the Linux scheduler and interrupt configuration. The previous framework for control and communication has been replaced by MARTe, a modern framework for real-time control gaining interest in the fusion community. The usage of MARTe allowed a rapid development of the control system and, in particular, its intrinsic simulation ability gave us the possibility of carrying out most debugging in simulation, without affecting machine operation. As a result the whole system has been finally commissioned in RFX in only two weeks.

  16. Effect of Radiotherapy Interruptions on Survival in Medicare Enrollees With Local and Regional Head-and-Neck Cancer

    International Nuclear Information System (INIS)

    Fesinmeyer, Megan Dann; Mehta, Vivek; Blough, David; Tock, Lauri; Ramsey, Scott D.

    2010-01-01

    Purpose: To investigate whether interruptions in radiotherapy are associated with decreased survival in a population-based sample of head-and-neck cancer patients. Methods and Materials: Using the Surveillance, Epidemiology, and End Results-Medicare linked database we identified Medicare beneficiaries aged 66 years and older diagnosed with local-regional head-and-neck cancer during the period 1997-2003. We examined claims records of 3864 patients completing radiotherapy for the presence of one or more 5-30-day interruption(s) in therapy. We then performed Cox regression analyses to estimate the association between therapy interruptions and survival. Results: Patients with laryngeal tumors who experienced an interruption in radiotherapy had a 68% (95% confidence interval, 41-200%) increased risk of death, compared with patients with no interruptions. Patients with nasal cavity, nasopharynx, oral, salivary gland, and sinus tumors had similar associations between interruptions and increased risk of death, but these did not reach statistical significance because of small sample sizes. Conclusions: Treatment interruptions seem to influence survival time among patients with laryngeal tumors completing a full course of radiotherapy. At all head-and-neck sites, the association between interruptions and survival is sensitive to confounding by stage and other treatments. Further research is needed to develop methods to identify patients most susceptible to interruption-induced mortality.

  17. The Effects of Career Interruptions on Young Men and Women.

    Science.gov (United States)

    Shorten, Brett; Lewis, Donald E.

    1991-01-01

    Data from a sample of 5,837 Australians showed that (1) women had longer career interruptions; (2) regardless of number of interruptions, men had higher wages; (3) longer interruptions had a negative effect on reentry wages; and (4) 1985-88 growth in wages for males was enhanced by increased numbers and length of interruptions, with the opposite…

  18. HIV Reactivation from Latency after Treatment Interruption Occurs on Average Every 5-8 Days--Implications for HIV Remission.

    Directory of Open Access Journals (Sweden)

    Mykola Pinkevych

    2015-07-01

    Full Text Available HIV infection can be effectively controlled by anti-retroviral therapy (ART in most patients. However therapy must be continued for life, because interruption of ART leads to rapid recrudescence of infection from long-lived latently infected cells. A number of approaches are currently being developed to 'purge' the reservoir of latently infected cells in order to either eliminate infection completely, or significantly delay the time to viral recrudescence after therapy interruption. A fundamental question in HIV research is how frequently the virus reactivates from latency, and thus how much the reservoir might need to be reduced to produce a prolonged antiretroviral-free HIV remission. Here we provide the first direct estimates of the frequency of viral recrudescence after ART interruption, combining data from four independent cohorts of patients undergoing treatment interruption, comprising 100 patients in total. We estimate that viral replication is initiated on average once every ≈6 days (range 5.1- 7.6 days. This rate is around 24 times lower than previous thought, and is very similar across the cohorts. In addition, we analyse data on the ratios of different 'reactivation founder' viruses in a separate cohort of patients undergoing ART-interruption, and estimate the frequency of successful reactivation to be once every 3.6 days. This suggests that a reduction in the reservoir size of around 50-70-fold would be required to increase the average time-to-recrudescence to about one year, and thus achieve at least a short period of anti-retroviral free HIV remission. Our analyses suggests that time-to-recrudescence studies will need to be large in order to detect modest changes in the reservoir, and that macaque models of SIV latency may have much higher frequencies of viral recrudescence after ART interruption than seen in human HIV infection. Understanding the mean frequency of recrudescence from latency is an important first step in

  19. Accommodating interruptions: A grounded theory of young people with asthma.

    Science.gov (United States)

    Hughes, Mary; Savage, Eileen; Andrews, Tom

    2018-01-01

    The aim of this study was to develop an explanatory theory on the lives of young people with asthma, issues affecting them and the impact of asthma on their day-to-day lives. Accommodating Interruptions is a theory that explains young people's concerns about living with asthma. Although national and international asthma management guidelines exist, it is accepted that the symptom control of asthma among the young people population is poor. This study was undertaken using Classic Grounded Theory. Data were collected through in-depth interviews and clinic consultations with young people aged 11-16 years who had asthma for over 1 year. Data were also collected from participant diaries. Constant comparative analysis, theoretical coding and memo writing were used to develop the substantive theory. The theory explains how young people resolve their main concern of being restricted by Accommodating Interruptions in their lives. They do this by assimilating behaviours in balance finding, moderating influence, fitting in and assuming control minimising the effects of asthma on their everyday lives. The theory of Accommodating Interruptions explains young people's asthma management behaviours in a new way. It allows us to understand how and why young people behave the way they do because they want to participate and be included in everyday activities, events and relationships. The theory adds to the body of knowledge on how young people with asthma live their day-to-day lives and it challenges some existing viewpoints in the literature regarding their behaviours. The findings have implications for developing services to support young people in a more meaningful way as they accommodate the interruptions associated with asthma in their lives. © 2017 John Wiley & Sons Ltd.

  20. Cold standby repairable system with working vacations and vacation interruption

    Institute of Scientific and Technical Information of China (English)

    Baoliang Liu; Lirong Cui; Yanqing Wen

    2015-01-01

    This paper studies a cold standby repairable system with working vacations and vacation interruption. The repairman’s multiple vacations policy, the working vacations policy and the vacation interruption are considered simultaneously. The lifetime of components fol ows a phase-type (PH) distribution. The repair time in the regular repair period and the working vacation period fol ow other two PH distributions at different rates. For this sys-tem, the vector-valued Markov process governing the system is constructed. We obtain several important performance measures for the system in transient and stationary regimes applying matrix-analytic methods. Final y, a numerical example is given to il ustrate the results obtained.

  1. Real time control engineering systems and automation

    CERN Document Server

    Ng, Tian Seng

    2016-01-01

    This book covers the two broad areas of the electronics and electrical aspects of control applications, highlighting the many different types of control systems of relevance to real-life control system design. The control techniques presented are state-of-the-art. In the electronics section, readers will find essential information on microprocessor, microcontroller, mechatronics and electronics control. The low-level assembly programming language performs basic input/output control techniques as well as controlling the stepper motor and PWM dc motor. In the electrical section, the book addresses the complete elevator PLC system design, neural network plant control, load flow analysis, and process control, as well as machine vision topics. Illustrative diagrams, circuits and programming examples and algorithms help to explain the details of the system function design. Readers will find a wealth of computer control and industrial automation practices and applications for modern industries, as well as the educat...

  2. On Discrete Time Control of Continuous Time Systems

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad

    This report is meant as a supplement or an extension to the material used in connection to or after the courses Stochastic Adaptive Control (02421) and Static and Dynamic Optimization (02711) given at the department Department of Informatics and Mathematical Modelling, The Technical University...

  3. Interactive or interruptive? Instant messaging at work

    NARCIS (Netherlands)

    Ou, C.X.J.; Davison, R.M.

    2011-01-01

    The use of instant messaging (IM) technology at work is controversial, due to the interruptions it may cause and the difficulties associated with quantifying its benefits for individuals, teams and organizations. In this study, we investigate the use and impact of IM tools in the workplace. Based on

  4. Symbolic approximate time-optimal control

    NARCIS (Netherlands)

    Mazo, Manuel; Tabuada, Paulo

    There is an increasing demand for controller design techniques capable of addressing the complex requirements of today's embedded applications. This demand has sparked the interest in symbolic control where lower complexity models of control systems are used to cater for complex specifications given

  5. Stress Outcomes of Four Types of Perceived Interruptions.

    Science.gov (United States)

    Fletcher, Keaton A; Potter, Sean M; Telford, Britany N

    2018-03-01

    Objective We sought to define and measure four types of perceived interruptions and to examine their relationships with stress outcomes. Background Interruptions have been defined and measured in a variety of inconsistent ways. No study has simultaneously examined the subjective experience of all types of interruptions. Method First, we provide a synthesized definition and model of interruptions that aligns interruptions along two qualities: origin and degree of multitasking. Second, we create and validate a self-report measure of these four types of perceived interruptions within two samples (working undergraduate students and working engineers). Last, we correlate this measure with self-reported psychological and physical stress outcomes. Results Our results support the four-factor model of interruptions. Results further support the link between each of the four types of interruptions (intrusions, breaks, distractions, and a specific type of ruminations, discrepancies) and stress outcomes. Specifically, results suggest that distractions explain a unique portion of variance in stress outcomes above and beyond the shared variance explained by intrusions, breaks, and discrepancies. Conclusion The synthesized four-factor model of interruptions is an adequate representation of the overall construct of interruptions. Further, perceived interruptions can be measured and are significantly related to stress outcomes. Application Measuring interruptions by observation can be intrusive and resource intensive. Additionally, some types of interruptions may be internal and therefore unobservable. Our survey measure offers a practical alternative method for practitioners and researchers interested in the outcomes of interruptions, especially stress outcomes.

  6. A microcomputer real-time monitor for the control of a particle accelerator

    International Nuclear Information System (INIS)

    Ouali, M.

    1977-01-01

    The physical management of a particle accelerator requests the supervision and the control of a great number of parameters and various devices. A hierarchically structured multicomputer control system was implemented on the Synchrocyclotron of the 'Institut de Physique Nucleaire' at Orsay (France). A set of 3 microcomputers MICRAL (manufactured in France around an Intel 8080 microprocessor chip) is connected through a CAMAC link to an IBM 1130 central computer used for the general control. At the lowest level, measurements and supervisions are made by the means of special hardwired systems built in the Laboratory (the CSTIs). On the other hand, some measurements are done by using a conventional industrial data acquisition system. All these systems are managed by the 3 MICRALs, as also some independent devices (function generator, radioprotection beacons, beam profile encoders). A real-time monitor resident in the MICRAL computers is responsible for task activations, resource allocation and data exchange management, especially with the main control computer. It uses for the 6 interrupt levels of the MICRAL and it builds and manages in the memory a set of descriptive block and of data stacks [fr

  7. Effect of growth interruption on the crystalline quality and electrical properties of Ga-doped ZnO thin film deposited on quartz substrate by magnetron sputtering

    International Nuclear Information System (INIS)

    Lee, Geun-Hyoung

    2013-01-01

    Ga-doped ZnO(GZO) thin films were deposited on the quartz substrate by magnetron sputtering system with growth interruption technique. As the number of interruptions and interruption time increased, the carrier concentration and Hall mobility in GZO films significantly increased. As a result, the resistivity of GZO films decreased. The optical transmittance of GZO films also increased with the number of interruption and interruption time. The transmittance showed over 90% in visual region. Atomic force microscopy measurement showed that the film surface became smoother with an increase of the number of interruption. In addition, the crystalline quality and electrical properties of GZO films were more improved when the growth interruption was employed with a temperature gradient. - Highlights: • Ga-doped ZnO thin films were deposited with growth interruption technique. • The crystallinity of the films was improved with the number of interruptions. • The crystallinity of the films was improved as the interruption time increased. • The growth interruption with a temperature gradient more improved the film quality

  8. [Deliberate interruptions and changes of dose of inhaled corticosteroids by asthma patients: "a community pharmacy study"].

    Science.gov (United States)

    Laforest, L; Van Ganse, É; Devouassoux, G; Chatté, G; Tamberou, C; Belhassen, M; Chamba, G

    2015-01-01

    Adherence to inhaled corticosteroids (ICS) remains a major issue for asthma management, even among patients receiving a regular prescription from their doctor. The frequency of deliberate interruption of ICS, and of spontaneous changes of dose, were studied in a population of asthma patients recruited in community pharmacies. Asthma patients (aged 18-50) recruited in community pharmacies reported in self-administered questionnaires their spontaneous interruptions and changes of doses of ICS during the past 3 months. The characteristics of patients who interrupted their therapy or who modified the dose were compared with other patients. The studied population included 252 patients (mean age 35 year-old, females: 59%), of whom 62% had inadequately controlled asthma. Among these patients, 25% had interrupted ICS therapy during the past 3 months, while 21% spontaneously changed the dose. The most reported reason for interrupting ICS was the cessation of symptoms (50%). In multivariate analysis, interrupting ICS was mainly associated with inadequate asthma control (OR=3.1, 95% CI 1.5-6.4), while the strongest association with changing ICS doses was the patients' perception of asthma as a concern in their lives (OR=3.2, 95% CI 1.2-8.4). These results underline a poor understanding of the purpose of ICS therapy by patients. They also highlight the need of therapeutic education to improve the management of the disease. Copyright © 2014 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  9. Control bandwidth improvements in GRAVITY fringe tracker by switching to a synchronous real time computer architecture

    Science.gov (United States)

    Abuter, Roberto; Dembet, Roderick; Lacour, Sylvestre; di Lieto, Nicola; Woillez, Julien; Eisenhauer, Frank; Fedou, Pierre; Phan Duc, Than

    2016-08-01

    The new VLTI (Very Large Telescope Interferometer) 1 instrument GRAVITY5, 22, 23 is equipped with a fringe tracker16 able to stabilize the K-band fringes on six baselines at the same time. It has been designed to achieve a performance for average seeing conditions of a residual OPD (Optical Path Difference) lower than 300 nm with objects brighter than K = 10. The control loop implementing the tracking is composed of a four stage real time computer system compromising: a sensor where the detector pixels are read in and the OPD and GD (Group Delay) are calculated; a controller receiving the computed sensor quantities and producing commands for the piezo actuators; a concentrator which combines both the OPD commands with the real time tip/tilt corrections offloading them to the piezo actuator; and finally a Kalman15 parameter estimator. This last stage is used to monitor current measurements over a window of few seconds and estimate new values for the main Kalman15 control loop parameters. The hardware and software implementation of this design runs asynchronously and communicates the four computers for data transfer via the Reflective Memory Network3. With the purpose of improving the performance of the GRAVITY5, 23 fringe tracking16, 22 control loop, a deviation from the standard asynchronous communication mechanism has been proposed and implemented. This new scheme operates the four independent real time computers involved in the tracking loop synchronously using the Reflective Memory Interrupts2 as the coordination signal. This synchronous mechanism had the effect of reducing the total pure delay of the loop from 3.5 [ms] to 2.0 [ms] which then translates on a better stabilization of the fringes as the bandwidth of the system is substantially improved. This paper will explain in detail the real time architecture of the fringe tracker in both is synchronous and synchronous implementation. The achieved improvements on reducing the delay via this mechanism will be

  10. Robust control of time-delay chaotic systems

    International Nuclear Information System (INIS)

    Hua Changchun; Guan Xinping

    2003-01-01

    Robust control problem of nonlinear time-delay chaotic systems is investigated. For such uncertain systems, we propose adaptive feedback controller and novel nonlinear feedback controller. They are both independent of the time delay and can render the corresponding closed-loop systems globally uniformly ultimately bounded stable. The simulations on controlling logistic system are made and the results show the controllers are feasible

  11. Cerebrospinal fluid signs of neuronal damage after antiretroviral treatment interruption in HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Deeks Steven G

    2005-08-01

    Full Text Available Abstract Background The neurofilament is a major structural component of myelinated axons. Increased cerebrospinal fluid (CSF concentrations of the light chain of the neurofilament protein (NFL can serve as a sensitive indicator of central nervous system (CNS injury. To assess whether interrupting antiretroviral treatment of HIV infection might have a deleterious effect on the CNS, we measured NFL levels in HIV-infected subjects interrupting therapy. We identified subjects who had CSF HIV RNA concentrations below 50 copies/mL at the time combination antiretroviral therapy was interrupted, and for whom CSF samples were available before and after the interruption. Results A total of 8 subjects were studied. The median (range CSF NFL level at baseline was Conclusion These findings suggest that resurgence of active HIV replication may result in measurable, albeit subclinical, CNS injury. Further studies are needed to define the frequency and pathobiological importance of the increase in CSF NFL.

  12. Motor control by precisely timed spike patterns

    DEFF Research Database (Denmark)

    Srivastava, Kyle H; Holmes, Caroline M; Vellema, Michiel

    2017-01-01

    whether the information in spike timing actually plays a role in brain function. By examining the activity of individual motor units (the muscle fibers innervated by a single motor neuron) and manipulating patterns of activation of these neurons, we provide both correlative and causal evidence......A fundamental problem in neuroscience is understanding how sequences of action potentials ("spikes") encode information about sensory signals and motor outputs. Although traditional theories assume that this information is conveyed by the total number of spikes fired within a specified time...... interval (spike rate), recent studies have shown that additional information is carried by the millisecond-scale timing patterns of action potentials (spike timing). However, it is unknown whether or how subtle differences in spike timing drive differences in perception or behavior, leaving it unclear...

  13. Genetic control of flowering time in legumes

    Directory of Open Access Journals (Sweden)

    James L Weller

    2015-04-01

    Full Text Available The timing of flowering, and in particular the degree to which it is responsive to the environment, is a key factor in the adaptation of a given species to various eco-geographic locations and agricultural practices. Flowering time variation has been documented in many crop legumes, and selection for specific variants has permitted significant expansion and improvement in cultivation, from prehistoric times to the present day. Recent advances in legume genomics have accelerated the process of gene identification and functional analysis, and opened up new prospects for a molecular understanding of flowering time adaptation in this important crop group. Within the legumes, two species have been prominent in flowering time studies; the vernalization-responsive long-day species pea (Pisum sativum and the warm-season short-day plant soybean (Glycine max. Analysis of flowering in these species is now being complemented by reverse genetics capabilities in the model legumes Medicago truncatula and Lotus japonicus, and the emergence of genome-scale resources in a range of other legumes. This review will outline the insights gained from detailed forward genetic analysis of flowering time in pea and soybean, highlighting the importance of light perception, the circadian clock and the FT family of flowering integrators. It discusses the current state of knowledge on genetic mechanisms for photoperiod and vernalization response, and concludes with a broader discussion of flowering time adaptation across legumes generally.

  14. Time Series Analysis Forecasting and Control

    CERN Document Server

    Box, George E P; Reinsel, Gregory C

    2011-01-01

    A modernized new edition of one of the most trusted books on time series analysis. Since publication of the first edition in 1970, Time Series Analysis has served as one of the most influential and prominent works on the subject. This new edition maintains its balanced presentation of the tools for modeling and analyzing time series and also introduces the latest developments that have occurred n the field over the past decade through applications from areas such as business, finance, and engineering. The Fourth Edition provides a clearly written exploration of the key methods for building, cl

  15. Assessment of treatment interruption among pulmonary tuberculosis patients: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Satya Bhgath Gorityala

    2015-01-01

    Full Text Available Background: Multi-drug resistant tuberculosis (TB is a rising peril of the TB control in India caused mostly by incomplete treatment. Aim: The aim was to assess the treatment interruption among pulmonary TB (PTB patients. Materials and Methods: A cross-sectional study was carried out for a period of 9 months among PTB patients. Patients admitted with active pulmonary Koch′s and history of anti-TB treatment (ATT for 1-month or more from any source and who returns to treatment after not taking ATT consecutively for 2 months or more were included in the study. The data were collected from the patients or their caretakers to obtain the source of treatment given previously before default, number of treatment interruptions, phase and reasons for treatment interruption treatment. Results: A total of 107 defaulters were identified during the study period. In the present study, 62.6% of the patients interrupted treatment only once, 55.34% of the patient′s early continuation (3-4 months treatment, and 47.66% of the patient′s only one reason for the treatment interruptions during the course of the treatment. The most common reason for the treatment interruptions were felt well with TB treatment (29.53% followed by side effects (16.06%, lack of money (8.29%, and other reasons. Conclusion: The study revealed that most of the defaulters were in the age group between 35 and 60 years, male gender, illiterates, daily wage labor, and married. The treatment interruptions were minimized by putting the efforts to improve direct supervision; pretreatment counseling and retrieve treatment interrupters were recommended.

  16. Administrative Lead Time at Navy Inventory Control Points

    National Research Council Canada - National Science Library

    Granetto, Paul

    1994-01-01

    .... We also evaluated the internal controls established for administrative lead time and the adequacy of management's implementation of the DoD Internal Management Control Program for monitoring administrative lead time...

  17. Sex Discrimination and Women's Labor Market Interruptions

    OpenAIRE

    David Neumark

    1993-01-01

    The human capital explanation of sex differences in wages is that women intend to work in the labor market more intermittently than men, and therefore invest less. This lower investment leads to lower wages and wage growth. The alternative "feedback" hypothesis consistent with the same facts is that women experience labor market discrimination and respond with career interruptions and specialization in household production. This paper explores the relationship between self-reported discrimina...

  18. Treatment interruptions: Statistics, causes and management in service radiotherapy; Interrupciones de tratamiento: estadistica, causa y manejo en un servicio de radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Ferrando Sanchez, A.; Milanes Gaillet, A. I.; Eugui Martinez, R.; Crespo Diaz, M. P.

    2013-07-01

    Despite the clinical maximum administer the prescribed dose at a given time, treatment interruptions are unavoidable in practice. In tumors quickly reproduce no evidence that the prolongation thereof entails loss of tumor control. It has tracked two of these conditions: squamous cell cancer of the head and neck (SCCHN) and lung cancer (NSCLC) over 2011 and 2012 to evaluate both the number of stops treatment as the reason for them and its management. (Author)

  19. Microdose flare protocol with interrupted follicle stimulating hormone and added androgen for poor responders--an observational pilot study.

    Science.gov (United States)

    Mitri, Frederic; Behan, Lucy Ann; Murphy, Courtney A; Hershko-Klement, Anat; Casper, Robert F; Bentov, Yaakov

    2016-01-01

    To investigate whether temporarily withholding FSH and adding androgen could improve follicular response during a microdose flare protocol in women with slow follicular growth or asynchronous follicular development. Observational pilot study. University-affiliated private fertility center. Twenty-six women aged 34-47 years with poor response to stimulation or a previous cancelled IVF cycle and with slow or asynchronous follicular growth during a microdose flare cycle. For 13 women, after initiation of ovarian stimulation using the microdose flare protocol, gonadotropin administration was interrupted and transdermal testosterone gel was added for several days (4.4 ± 1.2 d) starting after cycle day 7 (mean cycle day 10 ± 2.6). FSH, E2, follicular growth, and total number of mature oocytes retrieved were determined for all of the patients. Cycle cancellation rate as well as pregnancy rate following embryo transfer were also documented when applicable. FSH levels declined (25.2 ± 6.5 to 6.8 ± 3.2 IU/L), E2 levels increased (896 ± 687 to 2,163 ± 1,667 pmol/L), and follicular growth improved significantly during gonadotropin interruption and were tracked for 2 days during this time frame. The average number of oocytes retrieved was 5.3 ± 2.6, and the ratio of mature to total oocytes was 4:5. Four of the 13 women in the interruption group conceived following frozen embryo transfer, whereas none in the control group did. The androgen-interrupted FSH protocol may improve follicular response to gonadotropins in cycles that might otherwise be cancelled. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  20. Failure modes and natural control time for distributed vibrating systems

    International Nuclear Information System (INIS)

    Reid, R.M.

    1994-01-01

    The eigenstructure of the Gram matrix of frequency exponentials is used to study linear vibrating systems of hyperbolic type with distributed control. Using control norm as a practical measure of controllability and the vibrating string as a prototype, it is demonstrated that hyperbolic systems have a natural control time, even when only finitely many modes are excited. For shorter control times there are identifiable control failure modes which can be steered to zero only with very high cost in control norm. Both natural control time and the associated failure modes are constructed for linear fluids, strings, and beams, making note of the essential algorithms and Mathematica code, and displaying results graphically

  1. Implicit and explicit timing in oculomotor control.

    Directory of Open Access Journals (Sweden)

    Ilhame Ameqrane

    Full Text Available The passage of time can be estimated either explicitly, e.g. before leaving home in the morning, or implicitly, e.g. when catching a flying ball. In the present study, the latency of saccadic eye movements was used to evaluate differences between implicit and explicit timing. Humans were required to make a saccade between a central and a peripheral position on a computer screen. The delay between the extinction of a central target and the appearance of an eccentric target was the independent variable that could take one out of four different values (400, 900, 1400 or 1900 ms. In target trials, the delay period lasted for one of the four durations randomly. At the end of the delay, a saccade was initiated by the appearance of an eccentric target. Cue&target trials were similar to target trials but the duration of the delay was visually cued. In probe trials, the duration of the upcoming delay was cued, but there was no eccentric target and subjects had to internally generate a saccade at the estimated end of the delay. In target and cue&target trials, the mean and variance of latency distributions decreased as delay duration increased. In cue&target trials latencies were shorter. In probe trials, the variance increased with increasing delay duration and scalar variability was observed. The major differences in saccadic latency distributions were observed between visually-guided (target and cue&target trials and internally-generated saccades (probe trials. In target and cue&target trials the timing of the response was implicit. In probe trials, the timing of the response was internally-generated and explicitly based on the duration of the visual cue. Scalar timing was observed only during probe trials. This study supports the hypothesis that there is no ubiquitous timing system in the brain but independent timing processes active depending on task demands.

  2. Physicians interrupted by mobile devices in hospitals: understanding the interaction between devices, roles, and duties.

    Science.gov (United States)

    Solvoll, Terje; Scholl, Jeremiah; Hartvigsen, Gunnar

    2013-03-07

    A common denominator of modern hospitals is a variety of communication problems. In particular, interruptions from mobile communication devices are a cause of great concern for many physicians. To characterize how interruptions from mobile devices disturb physicians in their daily work. The gathered knowledge will be subsequently used as input for the design and development of a context-sensitive communication system for mobile communications suitable for hospitals. This study adheres to an ethnographic and interpretive field research approach. The data gathering consisted of participant observations, non-structured and mostly ad hoc interviews, and open-ended discussions with a selected group of physicians. Eleven physicians were observed for a total of 135 hours during May and June 2009. The study demonstrates to what degree physicians are interrupted by mobile devices in their daily work and in which situations they are interrupted, such as surgery, examinations, and during patients/relatives high-importance level conversations. The participants in the study expected, and also indicated, that wireless phones probably led to more interruptions immediately after their introduction in a clinic, when compared to a pager, but this changed after a short while. The unpleasant feeling experienced by the caller when interrupting someone by calling them differs compared to sending a page message, which leaves it up to the receiver when to return the call. Mobile devices, which frequently interrupt physicians in hospitals, are a problem for both physicians and patients. The results from this study contribute to knowledge being used as input for designing and developing a prototype for a context-sensitive communication system for mobile communication suitable for hospitals. We combined these findings with results from earlier studies and also involved actual users to develop the prototype, CallMeSmart. This system intends to reduce such interruptions and at the same time

  3. Repeat interruptions in spinocerebellar ataxia type 10 expansions are strongly associated with epileptic seizures

    Science.gov (United States)

    McFarland, Karen N.; Liu, Jilin; Landrian, Ivette; Zeng, Desmond; Raskin, Salmo; Moscovich, Mariana; Gatto, Emilia M.; Ochoa, Adriana; Teive, Hélio A. G.; Rasmussen, Astrid; Ashizawa, Tetsuo

    2014-01-01

    Spinocerebellar ataxia type 10 (SCA10), an autosomal dominant neurodegenerative disorder, is the result of a non-coding, pentanucleotide repeat expansion within intron 9 of the Ataxin 10 gene. SCA10 patients present with pure cerebellar ataxia; yet, some families also have a high incidence of epilepsy. SCA10 expansions containing penta- and heptanucleotide interruption motifs, termed “ATCCT interruptions,” experience large contractions during germline transmission, particularly in paternal lineages. At the same time, these alleles confer an earlier age at onset which contradicts traditional rules of genetic anticipation in repeat expansions. Previously, ATCCT interruptions have been associated with a higher prevalence of epileptic seizures in one Mexican-American SCA10 family. In a large cohort of SCA10 families, we analyzed whether ATCCT interruptions confers a greater risk for developing seizures in these families. Notably, we find that the presence of repeat interruptions within the SCA10 expansion confers a 6.3-fold increase in the risk of an SCA10 patient developing epilepsy (6.2-fold when considering patients of Mexican ancestry only) and a 13.7-fold increase in having a positive family history of epilepsy (10.5-fold when considering patients of Mexican ancestry only). We conclude that the presence of repeat interruptions in SCA10 repeat expansion indicates a significant risk for the epilepsy phenotype and should be considered during genetic counseling. PMID:24318420

  4. Controlling gain one photon at a time

    Science.gov (United States)

    Schwartz, Gregory W; Rieke, Fred

    2013-01-01

    Adaptation is a salient property of sensory processing. All adaptational or gain control mechanisms face the challenge of obtaining a reliable estimate of the property of the input to be adapted to and obtaining this estimate sufficiently rapidly to be useful. Here, we explore how the primate retina balances the need to change gain rapidly and reliably when photons arrive rarely at individual rod photoreceptors. We find that the weakest backgrounds that decrease the gain of the retinal output signals are similar to those that increase human behavioral threshold, and identify a novel site of gain control in the retinal circuitry. Thus, surprisingly, the gain of retinal signals begins to decrease essentially as soon as background lights are detectable; under these conditions, gain control does not rely on a highly averaged estimate of the photon count, but instead signals from individual photon absorptions trigger changes in gain. DOI: http://dx.doi.org/10.7554/eLife.00467.001 PMID:23682314

  5. Time-delayed autosynchronous swarm control.

    Science.gov (United States)

    Biggs, James D; Bennet, Derek J; Dadzie, S Kokou

    2012-01-01

    In this paper a general Morse potential model of self-propelling particles is considered in the presence of a time-delayed term and a spring potential. It is shown that the emergent swarm behavior is dependent on the delay term and weights of the time-delayed function, which can be set to induce a stationary swarm, a rotating swarm with uniform translation, and a rotating swarm with a stationary center of mass. An analysis of the mean field equations shows that without a spring potential the motion of the center of mass is determined explicitly by a multivalued function. For a nonzero spring potential the swarm converges to a vortex formation about a stationary center of mass, except at discrete bifurcation points where the center of mass will periodically trace an ellipse. The analytical results defining the behavior of the center of mass are shown to correspond with the numerical swarm simulations.

  6. Time and Control in Teachers’ Work

    DEFF Research Database (Denmark)

    Lund, Henrik Lambrecht

    2017-01-01

    to changes in the temporal order of work among teachers in Denmark. A 2014 change in Danish legislation forced teachers to conduct all their work at their school. This caused the largest labor marked conflict seen in Denmark for many years, and the largest ever seen in the public sector. Before this change...... relationship between different types of tasks, division of labor, rhythms of time for socializing, communication practices, coordination, synchronization, etc....

  7. Controlling flow time delays in flexible manufacturing cells

    NARCIS (Netherlands)

    Slomp, J.; Caprihan, R.; Bokhorst, J. A. C.

    2009-01-01

    Flow time delays in Flexible Manufacturing Cells (FMCs) are caused by transport and clamping/reclamping activities. This paper shows how dynamic scheduling parameters may control the flow times of jobs and the available task windows for flow time delays.

  8. Time domain passivity controller for 4-channel time-delay bilateral teleoperation.

    Science.gov (United States)

    Rebelo, Joao; Schiele, Andre

    2015-01-01

    This paper presents an extension of the time-domain passivity control approach to a four-channel bilateral controller under the effects of time delays. Time-domain passivity control has been used successfully to stabilize teleoperation systems with position-force and position-position controllers; however, the performance with such control architectures is sub-optimal both with and without time delays. This work extends the network representation of the time-domain passivity controller to the four-channel architecture, which provides perfect transparency to the user without time delay. The proposed architecture is based on modelling the controllers as dependent voltage sources and using only series passivity controllers. The obtained results are shown on a one degree-of-freedom setup and illustrate the stabilization behaviour of the proposed controller when time delay is present in the communication channel.

  9. A real-time digital control, data acquisition and analysis system for the DIII-D multipulse Thomson scattering diagnostic

    International Nuclear Information System (INIS)

    Greenfield, C.M.; Campbell, G.L.; Carlstrom, T.N.; DeBoo, J.C.; Hsieh, C.-L.; Snider, R.T.; Trost, P.K.

    1990-10-01

    A VME-based real-time computer systems for laser control, data acquisition and analysis for the DIII-D multipulse Thomson scattering diagnostic is described. The laser control task requires precise timing of up to 8 Nd:YAG lasers, each with an average firing rate of 20 Hz. A cpu module in real-time multiprocessing computer system will operate the lasers with evenly staggered laser pulses or in a ''burst mode'', where all available (fully charged) lasers can be fired at 50--100 μsec intervals upon receipt of an external event trigger signal. One of more cpu modules, along with a LeCroy FERA (Fast Encoding and Readout ADC) system, will perform real-time data acquisition and analysis. Partial electron temperature and density profiles will be available for plasma feedback control within 1 msec following each laser pulse. The VME-based computer system consists of 2 or more target processor modules (25 MHz Motorola 68030) running the VMEexec real-time operating system connected to a Unix based host system (also a 68030). All real-time software is fully interrupt driven to maximize system efficiency. Operator interaction and (non real-time) data analysis takes place on a MicroVAX 3400 connected via DECnet. 17 refs., 1 fig

  10. Real-time digital control, data acquisition, and analysis system for the DIII-D multipulse Thomson scattering diagnostic

    International Nuclear Information System (INIS)

    Greenfield, C.M.; Campbell, G.L.; Carlstrom, T.N.; DeBoo, J.C.; Hsieh, C.; Snider, R.T.; Trost, P.K.

    1990-01-01

    A VME-based real-time computer system for laser control, data acquisition, and analysis for the DIII-D multipulse Thomson scattering diagnostic is described. The laser control task requires precise timing of up to eight Nd:YAG lasers, each with an average firing rate of 20 Hz. A cpu module in a real-time multiprocessing computer system will operate the lasers with evenly staggered laser pulses or in a ''burst mode,'' where all available (fully charged) lasers can be fired at 50--100 μs intervals upon receipt of an external event trigger signal. One or more cpu modules, along with a LeCroy FERA (fast encoding and readout ADC) system, will perform real-time data acquisition and analysis. Partial electron temperature and density profiles will be available for plasma feedback control within 1 ms following each laser pulse. The VME-based computer system consists of two or more target processor modules (25 MHz Motorola 68030) running the VMEexec real-time operating system connected to a Unix-based host system (also a 68030). All real-time software is fully interrupt driven to maximize system efficiency. Operator interaction and (non-real-time) data analysis takes place on a MicroVAX 3400 connected via DECnet

  11. Time Stamp Synchronization of PEFP Distributed Control Systems

    International Nuclear Information System (INIS)

    Song, Young Gi; An, Eun Mi; Kwon, Hyeok Jung; Cho, Yong Sub

    2010-01-01

    Proton Engineering Frontier Project (PEFP) proton linac consists of several types of control systems, such as soft Input Output Controllers (IOC) and embedded IOC based on Experimental Physics Industrial Control System (EPICS) for each subsection of PEFP facility. One of the important factors is that IOC's time clock is synchronized. The synchronized time and time stamp can be achieved with Network Time Protocol (NTP) and EPICS time stamp record without timing hardware. The requirement of the time accuracy of IOCs is less than 1 second. The main objective of this study is to configure a master clock and produce Process Variable (PV) time stamps using local CPU time synchronized from the master clock. The distributed control systems are attached on PEFP control network

  12. Discrete-time inverse optimal control for nonlinear systems

    CERN Document Server

    Sanchez, Edgar N

    2013-01-01

    Discrete-Time Inverse Optimal Control for Nonlinear Systems proposes a novel inverse optimal control scheme for stabilization and trajectory tracking of discrete-time nonlinear systems. This avoids the need to solve the associated Hamilton-Jacobi-Bellman equation and minimizes a cost functional, resulting in a more efficient controller. Design More Efficient Controllers for Stabilization and Trajectory Tracking of Discrete-Time Nonlinear Systems The book presents two approaches for controller synthesis: the first based on passivity theory and the second on a control Lyapunov function (CLF). Th

  13. The Timing and Fast Control Demonstrator

    CERN Document Server

    Chen, Jiheng; Gustafsson, Leif

    In this thesis, the feasibility of an FPGA to host a system for generating and distributing clocks as well as distributing synchronous and asynchronous commands is tested. This system will be an imitation of the SHiP (Search for Hidden Particle) DAQ (Data Acquisition) system led by CERN. The practical implementation is to mainly apply Altera Cyclone V GT development board attached with SFP+ daughter card to achieve accurate timing and high speed performance. Experiments include three loopback test implementations. Loopback test is the simplest technique to assess a channel’s integration. The first one is the Ethernet loopback test. An Ethernet card daughter board is inserted to the HSMC port of the Cyclone V GT development board. After that, a SFP card is applied alternatively on the same port to do the similar loopback test but at a much higher speed via optical fibers. And finally, a more advanced XAUI to SFP+ card daughter board will be used to replace the previous SFP card in order to get a further spee...

  14. Workflow interruptions, social stressors from supervisor(s) and attention failure in surgery personnel.

    Science.gov (United States)

    Pereira, Diana; Müller, Patrick; Elfering, Achim

    2015-01-01

    Workflow interruptions and social stressors among surgery personnel may cause attention failure at work that may increase rumination about work issues during leisure time. The test of these assumptions should contribute to the understanding of exhaustion in surgery personnel and patient safety. Workflow interruptions and supervisor-related social stressors were tested to predict attention failure that predicts work-related rumination during leisure time. One hundred ninety-four theatre nurses, anaesthetists and surgeons from a Swiss University hospital participated in a cross-sectional survey. The participation rate was 58%. Structural equation modelling confirmed both indirect paths from workflow interruptions and social stressors via attention failure on rumination (both pworkflow interruptions and social stressors on rumination-could not be empirically supported. Workflow interruptions and social stressors at work are likely to trigger attention failure in surgery personnel. Work redesign and team intervention could help surgery personnel to maintain a high level of quality and patient safety and detach from work related issues to recover during leisure time.

  15. Development of a prototype solid state fault current limiting and interrupting device for low voltage distribution networks.

    OpenAIRE

    Ahmed, M.; Putrus, G. A.; Ran, L.; Penlington, R.

    2006-01-01

    This paper describes the development of a solid-state Fault Current Limiting and Interrupting Device (FCLID) suitable for low voltage distribution networks. The main components of the FCLID are a bidirectional semiconductor switch that can disrupt the short-circuit current, and a voltage clamping element that helps in controlling the current and absorbing the inductive energy stored in the network during current interruption. Using a hysteresis type control algorithm, the short-circuit curren...

  16. Effects of computing time delay on real-time control systems

    Science.gov (United States)

    Shin, Kang G.; Cui, Xianzhong

    1988-01-01

    The reliability of a real-time digital control system depends not only on the reliability of the hardware and software used, but also on the speed in executing control algorithms. The latter is due to the negative effects of computing time delay on control system performance. For a given sampling interval, the effects of computing time delay are classified into the delay problem and the loss problem. Analysis of these two problems is presented as a means of evaluating real-time control systems. As an example, both the self-tuning predicted (STP) control and Proportional-Integral-Derivative (PID) control are applied to the problem of tracking robot trajectories, and their respective effects of computing time delay on control performance are comparatively evaluated. For this example, the STP (PID) controller is shown to outperform the PID (STP) controller in coping with the delay (loss) problem.

  17. Discrete-Time LPV Current Control of an Induction Motor

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    2003-01-01

    In this paper we apply a new method for gain-scheduled output feedback control of nonlinear systems to current control of an induction motor. The method relies on recently developed controller synthesis results for linear parameter-varying (LPV) systems, where the controller synthesis is formulated...... as a set of linear matrix inequalities with full-block multipliers. A standard nonlinear model of the motor is constructed and written on LPV form. We then show that, although originally developed in continuous time, the controller synthesis results can be applied to a discrete-time model as well without...... further complications. The synthesis method is applied to the model, yielding an LPV discrete-time controller. Finally, the efficiency of the control scheme is validated via simulations as well as on the actual induction motor, both in open-loop current control and when an outer speed control loop...

  18. A distributed timing system for synchronizing control and data correlation

    International Nuclear Information System (INIS)

    Stettler, M.; Thuot, M.; Dalesio, L.R.; Cole, R.; Fite, C.; Slentz, G.; Warren, D.

    1992-01-01

    Synchronization is necessary in experimental physics machines to provide positive control over related events. The Ground Test Accelerator (GTA) timing system provides this function through a distributed control system, known as the Experimental Physics and Industrial Control System (EPICS). The EPICS timing system was designed to take advantage of a distributed architecture, and provides time stamping for synchronous data correlation as well as event control. The system has been successfully demonstrated on over a dozen controller nodes for operation and data analysis. The design of the hardware, software, and operational results are discussed. (author). 2 refs., 4 figs

  19. A distributed timing system for sychronizing control and data correlation

    International Nuclear Information System (INIS)

    Stettler, M.; Thout, M.; Dalesio, L.R.; Cole, R.; Fite, C.; Slentz, G.; Warren, D.

    1992-01-01

    Synchronization is necessary in experimental physics machines to provide positive control over related events. The Ground Test Accelerator (GTA) timing system provides this function through a distributed control system, known as the Experimental Physics and Industrial Control System (EPICS). The EPICS timing system was designed to take advantage of a distributed architecture, and provides time stamping for synchronous data correlation as well as event control. The system has been successfully demonstrated on over a dozen controller nodes for operation and data analysis. The design of the hardware, software, and operational results are discussed

  20. Discrete-Time LPV Current Control of an Induction Motor

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    2001-01-01

    In this paper we apply a new method for gain-scheduled output feedback control of nonlinear systems to current control of an induction motor. The method relies on recently developed controller synthesis results for linear parameter-varying (LPV) systems, where the controller synthesis is formulated...... without further complications. The synthesis method is applied to the model, yielding an LPV discrete-time controller. Finally, the efficiency of the control scheme is validated via simulations as well as experimentally on the actual induction motor, both in open-loop current control and when an outer...... speed control loop is closed around the current loop...

  1. Discrete-Time LPV Current Control of an Induction Motor

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    2003-01-01

    In this paper we apply a new method for gain-scheduled output feedback control of nonlinear systems to current control of an induction motor. The method relies on recently developed controller synthesis results for linear parameter-varying (LPV) systems, where the controller synthesis is formulated...... further complications. The synthesis method is applied to the model, yielding an LPV discrete-time controller. Finally, the efficiency of the control scheme is validated via simulations as well as on the actual induction motor, both in open-loop current control and when an outer speed control loop...... is closed around the current loop....

  2. The interrupted power law and the size of shadow banking.

    Science.gov (United States)

    Fiaschi, Davide; Kondor, Imre; Marsili, Matteo; Volpati, Valerio

    2014-01-01

    Using public data (Forbes Global 2000) we show that the asset sizes for the largest global firms follow a Pareto distribution in an intermediate range, that is "interrupted" by a sharp cut-off in its upper tail, where it is totally dominated by financial firms. This flattening of the distribution contrasts with a large body of empirical literature which finds a Pareto distribution for firm sizes both across countries and over time. Pareto distributions are generally traced back to a mechanism of proportional random growth, based on a regime of constant returns to scale. This makes our findings of an "interrupted" Pareto distribution all the more puzzling, because we provide evidence that financial firms in our sample should operate in such a regime. We claim that the missing mass from the upper tail of the asset size distribution is a consequence of shadow banking activity and that it provides an (upper) estimate of the size of the shadow banking system. This estimate-which we propose as a shadow banking index-compares well with estimates of the Financial Stability Board until 2009, but it shows a sharper rise in shadow banking activity after 2010. Finally, we propose a proportional random growth model that reproduces the observed distribution, thereby providing a quantitative estimate of the intensity of shadow banking activity.

  3. Mediated interruptions of anaesthesia providers using predictions of workload from anaesthesia information management system data.

    Science.gov (United States)

    Epstein, R H; Dexter, F

    2012-09-01

    Perioperative interruptions generated electronically from anaesthesia information management systems (AIMS) can provide useful feedback, but may adversely affect task performance if distractions occur at inopportune moments. Ideally such interruptions would occur only at times when their impact would be minimal. In this study of AIMS data, we evaluated the times of comments, drugs, fluids and periodic assessments (e.g. electrocardiogram diagnosis and train-of-four) to develop recommendations for the timing of interruptions during the intraoperative period. The 39,707 cases studied were divided into intervals between: 1) enter operating room; 2) induction; 3) intubation; 4) surgical incision; and 5) end surgery. Five-minute intervals of no documentation were determined for each case. The offsets from the start of each interval when >50% of ongoing cases had completed initial documentation were calculated (MIN50). The primary endpoint for each interval was the percentage of all cases still ongoing at MIN50. Results were that the intervals from entering the operating room to induction and from induction to intubation were unsuitable for interruptions confirming prior observational studies of anaesthesia workload. At least 13 minutes after surgical incision was the most suitable time for interruptions with 92% of cases still ongoing. Timing was minimally affected by the type of anaesthesia, surgical facility, surgical service, prone positioning or scheduled case duration. The implication of our results is that for mediated interruptions, waiting at least 13 minutes after the start of surgery is appropriate. Although we used AIMS data, operating room information system data is also suitable.

  4. Foundation for a Time Interval Access Control Model

    National Research Council Canada - National Science Library

    Afinidad, Francis B; Levin, Timothy E; Irvine, Cynthia E; Nguyen, Thuy D

    2005-01-01

    A new model for representing temporal access control policies is introduced. In this model, temporal authorizations are represented by time attributes associated with both subjects and objects, and a time interval access graph...

  5. Real-time control of Tokamak plasmas: from control of physics to physics-based control

    International Nuclear Information System (INIS)

    Felici, F. A. A.

    2011-11-01

    Stable, high-performance operation of a tokamak requires several plasma control problems to be handled simultaneously. Moreover, the complex physics which governs the tokamak plasma evolution must be studied and understood to make correct choices in controller design. In this thesis, the two subjects have been merged, using control solutions as experimental tool for physics studies, and using physics knowledge for developing new advanced control solutions. The TCV tokamak at CRPP-EPFL is ideally placed to explore issues at the interface between plasma physics and plasma control, by combining a digital realtime control system with a flexible and powerful set of actuators, in particular the electron cyclotron heating and current drive system (ECRH/ECCD). This experimental platform has been used to develop and test new control strategies for three plasma physics instabilities: sawtooth, edge localized mode (ELM) and neoclassical tearing mode (NTM). The period of the sawtooth crash, a periodic MHD instability in the core of a tokamak plasma, can be varied by localized deposition of ECRH/ECCD near the q = 1 surface (q: safety factor). A sawtooth pacing controller was developed which is able to control the time of appearance of the next sawtooth crash. Each individual sawtooth period can be controlled in real-time. A similar scheme is applied to H-mode plasmas with type-I ELMs, where it is shown that pacing regularizes the ELM period. The regular, reproducible and therefore predictable sawtooth crashes have been used to study the relationship between sawteeth and NTMs. Postcrash MHD activity can provide the ‘seed’ island for an NTM, which then grows under its neoclassical bootstrap drive. The seeding of 3/2 NTMs by long sawtooth crashes can be avoided by preemptive, crash-synchronized EC power injection pulses at the q = 3/2 rational surface location. NTM stabilization experiments in which the ECRH deposition location is moved in real-time with steerable mirrors have

  6. Predictors of perioperative major bleeding in patients who interrupt warfarin for an elective surgery or procedure: Analysis of the BRIDGE trial.

    Science.gov (United States)

    Clark, Nathan P; Douketis, James D; Hasselblad, Vic; Schulman, Sam; Kindzelski, Andrei L; Ortel, Thomas L

    2018-01-01

    The use of low-molecular weight heparin bridge therapy during warfarin interruption for elective surgery/procedures increases bleeding. Other predictors of bleeding in this setting are not well described. BRIDGE was a randomized, double-blind, placebo-controlled trial of bridge therapy with dalteparin 100 IU/kg twice daily in patients with atrial fibrillation requiring warfarin interruption. Bleeding outcomes were documented from the time of warfarin interruption until up to 37 days postprocedure. Multiple logistic regression and time-dependent hazard models were used to identify major bleeding predictors. We analyzed 1,813 patients of whom 895 received bridging and 918 received placebo. Median patient age was 72.6 years, and 73.3% were male. Forty-one major bleeding events occurred at a median time of 7.0 days (interquartile range, 4.0-18.0 days) postprocedure. Bridge therapy was a baseline predictor of major bleeding (odds ratio [OR]=2.4, 95% CI: 1.2-4.8), as were a history of renal disease (OR=2.9, 95% CI: 1.4-6.0), and high-bleeding risk procedures (vs low-bleeding risk procedures) (OR=2.9, 95% CI: 1.4-5.9). Perioperative aspirin use (OR=3.6, 95% CI: 1.1-11.9) and postprocedure international normalized ratio >3.0 (OR=2.1, 95% CI: 1.5-3.1) were time-dependent predictors of major bleeding. Major bleeding was most common in the first 10 days compared with 11-37 days postprocedure (OR=3.5, 95% CI: 1.8-6.9). In addition to bridge therapy, perioperative aspirin use, postprocedure international normalized ratio >3.0, a history of renal failure, and having a high-bleeding risk procedure increase the risk of major bleeding around the time of an elective surgery/procedure requiring warfarin interruption. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Analysis of Data Interruption in an LTE Highway Scenario with Dual Connectivity

    DEFF Research Database (Denmark)

    Gimenez, Lucas Chavarria; Michaelsen, Per-Henrik; Pedersen, Klaus I.

    2016-01-01

    This study evaluates whether last versions of Long Term Evolution with dual connectivity are able to support the latency and reliability requirements for the upcoming vehicular use-cases and time-critical applications. Data interruption times during handovers and cell management operations are ev...

  8. Low-complexity controllers for time-delay systems

    CERN Document Server

    Özbay, Hitay; Bonnet, Catherine; Mounier, Hugues

    2014-01-01

    This volume in the newly established series Advances in Delays and Dynamics (ADD@S) provides a collection of recent results on the design and analysis of Low Complexity Controllers for Time Delay Systems. A widely used indirect method to obtain low order controllers for time delay systems is to design a controller for the reduced order model of the plant. In the dual indirect approach, an infinite dimensional controller is designed first for the original plant model; then, the controller is approximated by keeping track of the degradation in performance and stability robustness measures. The present volume includes new techniques used at different stages of the indirect approach. It also includes new direct design methods for fixed structure and low order controllers. On the other hand, what is meant by low complexity controller is not necessarily low order controller. For example, Smith predictor or similar type of controllers include a copy of the plant internally in the controller, so they are technically ...

  9. Integrals of Motion for Discrete-Time Optimal Control Problems

    OpenAIRE

    Torres, Delfim F. M.

    2003-01-01

    We obtain a discrete time analog of E. Noether's theorem in Optimal Control, asserting that integrals of motion associated to the discrete time Pontryagin Maximum Principle can be computed from the quasi-invariance properties of the discrete time Lagrangian and discrete time control system. As corollaries, results for first-order and higher-order discrete problems of the calculus of variations are obtained.

  10. Digital evaluation of the influence of interruption of the fixation process on radiographic contrast and base-plus-fog density in three commercial brands of radiographic films

    Directory of Open Access Journals (Sweden)

    Paula Verona Ragusa da Silva

    Full Text Available INTRODUCTION : With the interest in anticipating access to the result of intraoral radiography, the radiographic processing is frequently neglected, compromising image quality. OBJECTIVE : The aim of this study was to evaluate the influence of interrupting the fixation process on the radiographic contrast and base-plus-fog density (BPFD in three brands of periapical films. MATERIAL AND METHOD : Ninety radiographs were taken of an aluminum stepwedge and a lead plate for each brand, and they were divided according to the time of initial immersion in the fixative in: control group (without interrupting the fixing, 5, 10, 20, 30 and 40 seconds. During processing, films had the fixing stage stopped and were exposed to a negatoscope for 1 minute, then the fixation time of 10 minutes was completed. The radiographs were digitized and exported to Image Tool 3.0.software. RESULT : Kodak(r film showed no statistically significant differences between groups, while Agfa(r film presented difference in BPFD compared with Group 5 seconds, and Dentix(r film showed statistical difference in all groups in comparison with the control group. CONCLUSION : Under the conditions studied, Kodak(r film is not influenced by disruption of fixation as regards BPFD and image contrast, enabling early access to the results of radiographs, whereas Agfa(r film requires at least 10 seconds of initial fixation, and Dentix(r film obtains better results when the process of fixation is not interrupted.

  11. Bridging FPGA and GPU technologies for AO real-time control

    Science.gov (United States)

    Perret, Denis; Lainé, Maxime; Bernard, Julien; Gratadour, Damien; Sevin, Arnaud

    2016-07-01

    Our team has developed a common environment for high performance simulations and real-time control of AO systems based on the use of Graphics Processors Units in the context of the COMPASS project. Such a solution, based on the ability of the real time core in the simulation to provide adequate computing performance, limits the cost of developing AO RTC systems and makes them more scalable. A code developed and validated in the context of the simulation may be injected directly into the system and tested on sky. Furthermore, the use of relatively low cost components also offers significant advantages for the system hardware platform. However, the use of GPUs in an AO loop comes with drawbacks: the traditional way of offloading computation from CPU to GPUs - involving multiple copies and unacceptable overhead in kernel launching - is not well suited in a real time context. This last application requires the implementation of a solution enabling direct memory access (DMA) to the GPU memory from a third party device, bypassing the operating system. This allows this device to communicate directly with the real-time core of the simulation feeding it with the WFS camera pixel stream. We show that DMA between a custom FPGA-based frame-grabber and a computation unit (GPU, FPGA, or Coprocessor such as Xeon-phi) across PCIe allows us to get latencies compatible with what will be needed on ELTs. As a fine-grained synchronization mechanism is not yet made available by GPU vendors, we propose the use of memory polling to avoid interrupts handling and involvement of a CPU. Network and Vision protocols are handled by the FPGA-based Network Interface Card (NIC). We present the results we obtained on a complete AO loop using camera and deformable mirror simulators.

  12. Calculation method for control rod dropping time in reactor

    International Nuclear Information System (INIS)

    Nogami, Takeki; Kato, Yoshifumi; Ishino, Jun-ichi; Doi, Isamu.

    1996-01-01

    If a control rod starts dropping, the dropping speed is rapidly increased, then settled substantially constant, rapidly decreased when it reaches a dash pot. A second detection signal generated by removing an AC component from a first detection signal is differentiated twice. The time when the maximum value among the twice differentiated values is generated is determined as a time when the control rods starts dropping. The time when minimum value among the twice differentiated values is generated is determined as a time when the control rod reaches the dash pot of the reactor. The measuring time within a range from the time when the control rod starts dropping to the time when the control rod reaches the dash pot of the reactor is determined. As a result, processing for the calculation of the dropping start time and dash pot reaching time of the control rod can be automatized. Further, it is suffice to conduct differentiation twice till the reaching time, which can facilitate the processing thereby enabling to determine a reliable time range. (N.H.)

  13. Real time control of plasmas and ECRH systems on TCV

    NARCIS (Netherlands)

    Paley, J.I.; Felici, F.; Berrino, J.; Coda, S.; Cruz, N.; Duval, B.P.; Goodman, T.P.; Martin, Y.; Moret, J.-M.; Piras, F.; Rodrigues, A.P.; Santos, B.; Varandas, C.A.F.

    2008-01-01

    Developments in the real time control hardware on TCV paired with the flexibility of plasma shaping and ECRH actuators are opening many opportunities to perform real time experiments and develop algorithms and methods for fusion applications. The ability to control MHD instabilities is particularly

  14. On the application of Discrete Time Optimal Control Concepts to ...

    African Journals Online (AJOL)

    On the application of Discrete Time Optimal Control Concepts to Economic Problems. ... Journal of the Nigerian Association of Mathematical Physics ... Abstract. An extension of the use of the maximum principle to solve Discrete-time Optimal Control Problems (DTOCP), in which the state equations are in the form of general ...

  15. Task Interruption: Resumption Lag and the Role of Cues

    National Research Council Canada - National Science Library

    Altmann, Erik M; Trafton, J. G

    2004-01-01

    ...), indicating a substantial disruptive effect. To probe the nature of the disruption, they examined the role of external cues associated with the interrupted task and found that cues available immediately before an interruption facilitate performance immediately afterwards, thus reducing the resumption lag. This "cue-availability" effect suggests that people deploy preparatory perceptual and memory processes, apparently spontaneously, to mitigate the disruptive effects of task interruption.

  16. When daily planning improves employee performance: The importance of planning type, engagement, and interruptions.

    Science.gov (United States)

    Parke, Michael R; Weinhardt, Justin M; Brodsky, Andrew; Tangirala, Subrahmaniam; DeVoe, Sanford E

    2018-03-01

    Does planning for a particular workday help employees perform better than on other days they fail to plan? We investigate this question by identifying 2 distinct types of daily work planning to explain why and when planning improves employees' daily performance. The first type is time management planning (TMP)-creating task lists, prioritizing tasks, and determining how and when to perform them. We propose that TMP enhances employees' performance by increasing their work engagement, but that these positive effects are weakened when employees face many interruptions in their day. The second type is contingent planning (CP) in which employees anticipate possible interruptions in their work and plan for them. We propose that CP helps employees stay engaged and perform well despite frequent interruptions. We investigate these hypotheses using a 2-week experience-sampling study. Our findings indicate that TMP's positive effects are conditioned upon the amount of interruptions, but CP has positive effects that are not influenced by the level of interruptions. Through this study, we help inform workers of the different planning methods they can use to increase their daily motivation and performance in dynamic work environments. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  17. Direct output feedback control of discrete-time systems

    International Nuclear Information System (INIS)

    Lin, C.C.; Chung, L.L.; Lu, K.H.

    1993-01-01

    An optimal direct output feedback control algorithm is developed for discrete-time systems with the consideration of time delay in control force action. Optimal constant output feedback gains are obtained through variational process such that certain prescribed quadratic performance index is minimized. Discrete-time control forces are then calculated from the multiplication of output measurements by these pre-calculated feedback gains. According to the proposed algorithm, structural system is assured to remain stable even in the presence of time delay. The number of sensors and controllers may be very small as compared with the dimension of states. Numerical results show that direct velocity feedback control is more sensitive to time delay than state feedback but, is still quite effective in reducing the dynamic responses under earthquake excitation. (author)

  18. Discrete-time optimal control and games on large intervals

    CERN Document Server

    Zaslavski, Alexander J

    2017-01-01

    Devoted to the structure of approximate solutions of discrete-time optimal control problems and approximate solutions of dynamic discrete-time two-player zero-sum games, this book presents results on properties of approximate solutions in an interval that is independent lengthwise, for all sufficiently large intervals. Results concerning the so-called turnpike property of optimal control problems and zero-sum games in the regions close to the endpoints of the time intervals are the main focus of this book. The description of the structure of approximate solutions on sufficiently large intervals and its stability will interest graduate students and mathematicians in optimal control and game theory, engineering, and economics. This book begins with a brief overview and moves on to analyze the structure of approximate solutions of autonomous nonconcave discrete-time optimal control Lagrange problems.Next the structures of approximate solutions of autonomous discrete-time optimal control problems that are discret...

  19. A simple time-delayed method to control chaotic systems

    International Nuclear Information System (INIS)

    Chen Maoyin; Zhou Donghua; Shang Yun

    2004-01-01

    Based on the adaptive iterative learning strategy, a simple time-delayed controller is proposed to stabilize unstable periodic orbits (UPOs) embedded in chaotic attractors. This controller includes two parts: one is a linear feedback part; the other is an adaptive iterative learning estimation part. Theoretical analysis and numerical simulation show the effectiveness of this controller

  20. Landing-Time-Controlled Management Of Air Traffic

    Science.gov (United States)

    Erzberger, Heinz; Tobias, Leonard

    1988-01-01

    Conceptual system controls aircraft with old and new guidance equipment. Report begins with overview of concept, then reviews controller-interactive simulations. Describes fuel-conservative-trajectory algorithm, based on equations of motion for controlling landing time. Finally, presents results of piloted simulations.

  1. Predicting timing performance of advanced mechatronics control systems

    NARCIS (Netherlands)

    Voeten, J.P.M.; Hendriks, T.; Theelen, B.D.; Schuddemat, J.; Tabingh Suermondt, W.; Gemei, J.; Kotterink, C.; Huet, van J.; Eichler, G.; Kuepper, A.; Schau, V.; Fouchal, H.; Unger, H.

    2011-01-01

    Embedded control is a key product technology differentiator for many high-tech industries, including ASML. The strong increase in complexity of embedded control systems, combined with the occurrence of late changes in control requirements, results in many timing performance problems showing up only

  2. Controlling shareholders and market timing in share issuance

    NARCIS (Netherlands)

    Urzua Infante, F.; Larrain, B.

    2013-01-01

    We examine market timing in the equity issuance of firms controlled by large shareholders using a hand-collected data set of controlling shareholders' ownership stakes in Chile between 1990 and 2009. When a firm issues shares, the controlling shareholder can either maintain or change his ownership

  3. Real-time control systems: feedback, scheduling and robustness

    Science.gov (United States)

    Simon, Daniel; Seuret, Alexandre; Sename, Olivier

    2017-08-01

    The efficient control of real-time distributed systems, where continuous components are governed through digital devices and communication networks, needs a careful examination of the constraints arising from the different involved domains inside co-design approaches. Thanks to the robustness of feedback control, both new control methodologies and slackened real-time scheduling schemes are proposed beyond the frontiers between these traditionally separated fields. A methodology to design robust aperiodic controllers is provided, where the sampling interval is considered as a control variable of the system. Promising experimental results are provided to show the feasibility and robustness of the approach.

  4. Diagnosis of aortic interruption by CT angiography

    International Nuclear Information System (INIS)

    Shirani, Shapour; Soleymanzadeh, Maryam

    2013-01-01

    Interrupted aortic arch (IAA) is a rare congenital malformation of the aortic arch, which might be accompanied with other coexisting cardiovascular anomalies. Many cases with IAA are diagnosed at their neonatal and newborn period but in rare cases the diagnosis is not established until adulthood. The patients may have no clinical symptoms but the signs of heart failure will gradually appear and may cause death. The development of imaging methods such as computed tomography (CT) and magnetic resonance (MR) imaging has dramatically changed the diagnostics. Here we report a 20-year-old young man with IAA associated with sinus venosus atrial septal defect (SVD) and partial anomalous pulmonary venous connection (PAPVC) referred to our hospital

  5. Engineering applications of discrete-time optimal control

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui; Ravn, Hans V.

    1990-01-01

    Many problems of design and operation of engineering systems can be formulated as optimal control problems where time has been discretisized. This is also true even if 'time' is not involved in the formulation of the problem, but rather another one-dimensional parameter. This paper gives a review...... of some well-known and new results in discrete time optimal control methods applicable to practical problem solving within engineering. Emphasis is placed on dynamic programming, the classical maximum principle and generalized versions of the maximum principle for optimal control of discrete time systems...

  6. Discrete-Time Nonlinear Control of VSC-HVDC System

    Directory of Open Access Journals (Sweden)

    TianTian Qian

    2015-01-01

    Full Text Available Because VSC-HVDC is a kind of strong nonlinear, coupling, and multi-input multioutput (MIMO system, its control problem is always attracting much attention from scholars. And a lot of papers have done research on its control strategy in the continuous-time domain. But the control system is implemented through the computer discrete sampling in practical engineering. It is necessary to study the mathematical model and control algorithm in the discrete-time domain. The discrete mathematical model based on output feedback linearization and discrete sliding mode control algorithm is proposed in this paper. And to ensure the effectiveness of the control system in the quasi sliding mode state, the fast output sampling method is used in the output feedback. The results from simulation experiment in MATLAB/SIMULINK prove that the proposed discrete control algorithm can make the VSC-HVDC system have good static, dynamic, and robust characteristics in discrete-time domain.

  7. Decentralized control of discrete-time linear time invariant systems with input saturation

    NARCIS (Netherlands)

    Deliu, Ciprian; Deliu, C.; Malek, Babak; Roy, Sandip; Saberi, Ali; Stoorvogel, Antonie Arij

    2009-01-01

    We study decentralized stabilization of discrete time linear time invariant (LTI) systems subject to actuator saturation, using LTI controllers. The requirement of stabilization under both saturation constraints and decentralization impose obvious necessary conditions on the open-loop plant, namely

  8. Influence of Gap Distance on Vacuum Arc Characteristics of Cup Type AMF Electrode in Vacuum Interrupters

    International Nuclear Information System (INIS)

    Cheng Shaoyong; Xiu Shixin; Wang Jimei; Shen Zhengchao

    2006-01-01

    The greenhouse effect of SF 6 is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling technique are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device (CCD) video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 mm. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters

  9. Rapid resumption of interrupted visual search. New insights on the interaction between vision and memory.

    Science.gov (United States)

    Lleras, Alejandro; Rensink, Ronald A; Enns, James T

    2005-09-01

    A modified visual search task demonstrates that humans are very good at resuming a search after it has been momentarily interrupted. This is shown by exceptionally rapid response time to a display that reappears after a brief interruption, even when an entirely different visual display is seen during the interruption and two different visual searches are performed simultaneously. This rapid resumption depends on the stability of the visual scene and is not due to display or response anticipations. These results are consistent with the existence of an iterative hypothesis-testing mechanism that compares information stored in short-term memory (the perceptual hypothesis) with information about the display (the sensory pattern). In this view, rapid resumption occurs because a hypothesis based on a previous glance of the scene can be tested very rapidly in a subsequent glance, given that the initial hypothesis-generation step has already been performed.

  10. Neural Feedback Scheduling of Real-Time Control Tasks

    OpenAIRE

    Xia, Feng; Tian, Yu-Chu; Sun, Youxian; Dong, Jinxiang

    2008-01-01

    Many embedded real-time control systems suffer from resource constraints and dynamic workload variations. Although optimal feedback scheduling schemes are in principle capable of maximizing the overall control performance of multitasking control systems, most of them induce excessively large computational overheads associated with the mathematical optimization routines involved and hence are not directly applicable to practical systems. To optimize the overall control performance while minimi...

  11. Analysis of Time Delay Simulation in Networked Control System

    OpenAIRE

    Nyan Phyo Aung; Zaw Min Naing; Hla Myo Tun

    2016-01-01

    The paper presents a PD controller for the Networked Control Systems (NCS) with delay. The major challenges in this networked control system (NCS) are the delay of the data transmission throughout the communication network. The comparative performance analysis is carried out for different delays network medium. In this paper, simulation is carried out on Ac servo motor control system using CAN Bus as communication network medium. The True Time toolbox of MATLAB is used for simulation to analy...

  12. Engine control system having speed-based timing

    Science.gov (United States)

    Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

    2012-02-14

    A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

  13. Real time neutral beam power control on MAST

    Energy Technology Data Exchange (ETDEWEB)

    Homfray, David A., E-mail: david.homfray@ccfe.ac.uk [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Benn, A.; Ciric, D.; Day, I.; Dunkley, V.; Keeling, D.; Khilar, S.; King, D.; King, R. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Kurutz, U. [Department of Experimental Plasma Physics, University of Augsburg, Augsburg (Germany); Payne, D.; Simmonds, M.; Stevenson, P.; Tame, C. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom)

    2011-10-15

    Real time power control of neutral beam provides an excellent tool for many different plasma physics studies. Power control at a better resolution than the level of a single injector is usually achieved by modulating individual power supplies. However, the short beam slowing down time on MAST is such that the plasma would be sensitive to modulating the neutral beam using this 100% on-off pulse-width modulation method. A novel alternative method of power control has been demonstrated, where the arc current, and hence beam current, has been controlled in real time allowing variations in neutral beam power. This has been demonstrated in a MAST plasma with almost no loss of transmission as a consequence of the optical properties of the high perveance MAST neutral beam system. This paper will detail the methodology, experiment and results and discuss the full implementation of this method that will allow MAST to control the beam power in real time.

  14. Active controllers and the time duration to learn a task

    Science.gov (United States)

    Repperger, D. W.; Goodyear, C.

    1986-01-01

    An active controller was used to help train naive subjects involved in a compensatory tracking task. The controller is called active in this context because it moves the subject's hand in a direction to improve tracking. It is of interest here to question whether the active controller helps the subject to learn a task more rapidly than the passive controller. Six subjects, inexperienced to compensatory tracking, were run to asymptote root mean square error tracking levels with an active controller or a passive controller. The time required to learn the task was defined several different ways. The results of the different measures of learning were examined across pools of subjects and across controllers using statistical tests. The comparison between the active controller and the passive controller as to their ability to accelerate the learning process as well as reduce levels of asymptotic tracking error is reported here.

  15. Time-optimal control of infinite order distributed parabolic systems involving time lags

    Directory of Open Access Journals (Sweden)

    G.M. Bahaa

    2014-06-01

    Full Text Available A time-optimal control problem for linear infinite order distributed parabolic systems involving constant time lags appear both in the state equation and in the boundary condition is presented. Some particular properties of the optimal control are discussed.

  16. Concepts of real time and semi-real time material control

    International Nuclear Information System (INIS)

    Lovett, J.E.

    1975-01-01

    After a brief consideration of the traditional material balance accounting on an MBA basis, this paper explores the basic concepts of real time and semi-real time material control, together with some of the major problems to be solved. Three types of short-term material control are discussed: storage, batch processing, and continuous processing. (DLC)

  17. Prototyping Real-Time Control in the SPS

    CERN Document Server

    Andersson, J; Jensen, L; Jones, R; Lamont, M; Wenninger, J; Wijnands, Thijs; CERN. Geneva. AB Department

    2003-01-01

    Real-time control of beam related parameters will be required in the LHC. In order to gain experience of the issues involved in implementing distributed real-time control over large distances, a prototype local orbit feedback system is being developed in the SPS. This will use 6 pickups, each equipped with the full LHC acquisition electronics chain and linked to a real-time communication and feedback system. This reports summarises the .rst tests performed with this system in October 2002, where the data from four pickups was successfully acquired and displayed at 10 Hz in the control room.

  18. Time-varying linear control for tiltrotor aircraft

    Directory of Open Access Journals (Sweden)

    Jing ZHANG

    2018-04-01

    Full Text Available Tiltrotor aircraft have three flight modes: helicopter mode, airplane mode, and transition mode. A tiltrotor has characteristics of highly nonlinear, time-varying flight dynamics and inertial/control couplings in its transition mode. It can transit from the helicopter mode to the airplane mode by tilting its nacelles, and an effective controller is crucial to accomplish tilting transition missions. Longitudinal dynamic characteristics of the tiltrotor are described by a nonlinear Lagrange-form model, which takes into account inertial/control couplings and aerodynamic interferences. Reference commands for airspeed velocity and attitude in the transition mode are calculated dynamically by visiting a command library which is founded in advance by analyzing the flight envelope of the tiltrotor. A Time-Varying Linear (TVL model is obtained using a Taylor-expansion based online linearization technique from the nonlinear model. Subsequently, based on an optimal control concept, an online optimization based control method with input constraints considered is proposed. To validate the proposed control method, three typical tilting transition missions are simulated using the nonlinear model of XV-15 tiltrotor aircraft. Simulation results show that the controller can be used to control the tiltrotor throughout its operating envelop which includes a transition flight, and can also deal with vertical gust disturbances. Keywords: Constrained optimal control, Inertia/control couplings, Tiltrotor aircraft, Time-varying control, Transition mode

  19. Eventual Suicide in Interrupted and Uninterrupted Attempters: A Challenge to the Cry-for-Help Hypothesis.

    Science.gov (United States)

    Steer, Robert A.; And Others

    1988-01-01

    Followed patients (N=499) hospitalized for suicide attempts (attempters) between 1970 and 1975 until 1982. Found under six percent eventually committed suicide. Found the interrupted attempters were approximately three times more likely to commit suicide than were the uninterrupted attempters. (Author/ABL)

  20. Microcomputer-controlled world time display for public area viewing

    Science.gov (United States)

    Yep, S.; Rashidian, M.

    1982-05-01

    The design, development, and implementation of a microcomputer-controlled world clock is discussed. The system, designated international Time Display System (ITDS), integrates a Geochron Calendar Map and a microcomputer-based digital display to automatically compensate for daylight savings time, leap year, and time zone differences. An in-depth technical description of the design and development of the electronic hardware, firmware, and software systems is provided. Reference material on the time zones, fabrication techniques, and electronic subsystems are also provided.

  1. Greater physiological and behavioral effects of interrupted stress pattern compared to daily restraint stress in rats.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Repeated stress can trigger a range of psychiatric disorders, including anxiety. The propensity to develop abnormal behaviors after repeated stress is related to the severity, frequency and number of stressors. However, the pattern of stress exposure may contribute to the impact of stress. In addition, the anxiogenic nature of repeated stress exposure can be moderated by the degree of coping that occurs, and can be reflected in homotypic habituation to the repeated stress. However, expectations are not clear when a pattern of stress presentation is utilized that diminishes habituation. The purpose of these experiments is to test whether interrupted stress exposure decreases homotypic habituation and leads to greater effects on anxiety-like behavior in adult male rats. We found that repeated interrupted restraint stress resulted in less overall homotypic habituation compared to repeated daily restraint stress. This was demonstrated by greater production of fecal boli and greater corticosterone response to restraint. Furthermore, interrupted restraint stress resulted in a lower body weight and greater adrenal gland weight than daily restraint stress, and greater anxiety-like behavior in the elevated plus maze. Control experiments demonstrated that these effects of the interrupted pattern could not be explained by differences in the total number of stress exposures, differences in the total number of days that the stress periods encompased, nor could it be explained as a result of only the stress exposures after an interruption from stress. These experiments demonstrate that the pattern of stress exposure is a significant determinant of the effects of repeated stress, and that interrupted stress exposure that decreases habituation can have larger effects than a greater number of daily stress exposures. Differences in the pattern of stress exposure are therefore an important factor to consider when predicting the severity of the effects of repeated

  2. Real-time software for the COMPASS tokamak plasma control

    International Nuclear Information System (INIS)

    Valcarcel, D.F.; Duarte, A.S.; Neto, A.; Carvalho, I.S.; Carvalho, B.B.; Fernandes, H.; Sousa, J.; Sartori, F.; Janky, F.; Cahyna, P.; Hron, M.; Panek, R.

    2010-01-01

    The COMPASS tokamak has started its operation recently in Prague and to meet the necessary operation parameters its real-time system, for data processing and control, must be designed for both flexibility and performance, allowing the easy integration of code from several developers and to guarantee the desired time cycle. For this purpose an Advanced Telecommunications Computing Architecture based real-time system has been deployed with a solution built on a multi-core x86 processor. It makes use of two software components: the BaseLib2 and the MARTe (Multithreaded Application Real-Time executor) real-time frameworks. The BaseLib2 framework is a generic real-time library with optimized objects for the implementation of real-time algorithms. This allowed to build a library of modules that process the acquired data and execute control algorithms. MARTe executes these modules in kernel space Real-Time Application Interface allowing to attain the required cycle time and a jitter of less than 1.5 μs. MARTe configuration and data storage are accomplished through a Java hardware client that connects to the FireSignal control and data acquisition software. This article details the implementation of the real-time system for the COMPASS tokamak, in particular the organization of the control code, the design and implementation of the communications with the actuators and how MARTe integrates with the FireSignal software.

  3. Real-time software for the COMPASS tokamak plasma control

    Energy Technology Data Exchange (ETDEWEB)

    Valcarcel, D.F., E-mail: danielv@ipfn.ist.utl.p [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, P-1049-001 Lisboa (Portugal); Duarte, A.S.; Neto, A.; Carvalho, I.S.; Carvalho, B.B.; Fernandes, H.; Sousa, J. [Associacao EURATOM/IST, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, P-1049-001 Lisboa (Portugal); Sartori, F. [Euratom-UKAEA, Culham Science Centre, Abingdon, OX14 3DB Oxon (United Kingdom); Janky, F.; Cahyna, P.; Hron, M.; Panek, R. [Institute of Plasma Physics AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 182 00 Prague (Czech Republic)

    2010-07-15

    The COMPASS tokamak has started its operation recently in Prague and to meet the necessary operation parameters its real-time system, for data processing and control, must be designed for both flexibility and performance, allowing the easy integration of code from several developers and to guarantee the desired time cycle. For this purpose an Advanced Telecommunications Computing Architecture based real-time system has been deployed with a solution built on a multi-core x86 processor. It makes use of two software components: the BaseLib2 and the MARTe (Multithreaded Application Real-Time executor) real-time frameworks. The BaseLib2 framework is a generic real-time library with optimized objects for the implementation of real-time algorithms. This allowed to build a library of modules that process the acquired data and execute control algorithms. MARTe executes these modules in kernel space Real-Time Application Interface allowing to attain the required cycle time and a jitter of less than 1.5 {mu}s. MARTe configuration and data storage are accomplished through a Java hardware client that connects to the FireSignal control and data acquisition software. This article details the implementation of the real-time system for the COMPASS tokamak, in particular the organization of the control code, the design and implementation of the communications with the actuators and how MARTe integrates with the FireSignal software.

  4. A General Theory of Markovian Time Inconsistent Stochastic Control Problems

    DEFF Research Database (Denmark)

    Björk, Tomas; Murgochi, Agatha

    We develop a theory for stochastic control problems which, in various ways, are time inconsistent in the sense that they do not admit a Bellman optimality principle. We attach these problems by viewing them within a game theoretic framework, and we look for Nash subgame perfect equilibrium points...... examples of time inconsistency in the literature are easily seen to be special cases of the present theory. We also prove that for every time inconsistent problem, there exists an associated time consistent problem such that the optimal control and the optimal value function for the consistent problem...

  5. Real-Time Software for the Compass Tokamak Plasma Control

    Energy Technology Data Exchange (ETDEWEB)

    Valcarcel, D.F.; Duarte, A.S.; Neto, A.; Carvalho, I.S.; Carvalho, B.B.; Fernandes, H.; Sousa, J. [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Lisboa (Portugal); Sartori, F. [Euratom-UKAEA, Culham Science Centre, Abingdon, OX14 3DB Oxon (United Kingdom); Janky, F.; Cahyna, P.; Hron, M.; Panek, R. [Institute of Plasma Physics AS CR, v.v.i., Association EURATOM / IPP.CR, Prague (Costa Rica)

    2009-07-01

    This poster presents the flexible and high-performance real time system that guarantees the desired time cycles for plasma control on the COMPASS tokamak: 500 {mu}s for toroidal field, current, equilibrium and shaping; 50 {mu}s for fast control of the equilibrium and vertical instability. This system was developed on top of a high-performance processor and a software framework (MARTe) tailored for real-time. The preliminary measurements indicate that the time constraints will be met on the final solution. The system allows the making of modifications in the future to improve software components. (A.C.)

  6. Real-time communication for distributed plasma control systems

    Energy Technology Data Exchange (ETDEWEB)

    Luchetta, A. [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Corso Stati Uniti 4, Padova 35127 (Italy)], E-mail: adriano.luchetta@igi.cnr.it; Barbalace, A.; Manduchi, G.; Soppelsa, A.; Taliercio, C. [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Corso Stati Uniti 4, Padova 35127 (Italy)

    2008-04-15

    Real-time control applications will benefit in the near future from the enhanced performance provided by multi-core processor architectures. Nevertheless real-time communication will continue to be critical in distributed plasma control systems where the plant under control typically is distributed over a wide area. At RFX-mod real-time communication is crucial for hard real-time plasma control, due to the distributed architecture of the system, which consists of several VMEbus stations. The system runs under VxWorks and uses Gigabit Ethernet for sub-millisecond real-time communication. To optimize communication in the system, a set of detailed measurements has been carried out on the target platforms (Motorola MVME5100 and MVME5500) using either the VxWorks User Datagram Protocol (UDP) stack or raw communication based on the data link layer. Measurements have been carried out also under Linux, using its UDP stack or, in alternative, RTnet, an open source hard real-time network protocol stack. RTnet runs under Xenomai or RTAI, two popular real-time extensions based on the Linux kernel. The paper reports on the measurements carried out and compares the results, showing that the performance obtained by using open source code is suitable for sub-millisecond real-time communication in plasma control.

  7. Real-time Control Mediation in Agile Distributed Software Development

    DEFF Research Database (Denmark)

    Persson, John Stouby; Aaen, Ivan; Mathiassen, Lars

    2008-01-01

    Agile distributed environments pose particular challenges related to control of quality and collaboration in software development. Moreover, while face-to-face interaction is fundamental in agile development, distributed environments must rely extensively on mediated interactions. On this backdrop...... control was mediated over distance by technology through real-time exchanges. Contrary to previous research, the analysis suggests that both formal and informal elements of real-time mediated control were used; that evolving goals and adjustment of expectations were two of the main issues in real......-time mediated control exchanges; and, that the actors, despite distances in space and culture, developed a clan-like pattern mediated by technology to help control quality and collaboration in software development....

  8. Real-Time Application Performance Steering and Adaptive Control

    National Research Council Canada - National Science Library

    Reed, Daniel

    2002-01-01

    .... The objective of the Real-time Application Performance Steering and Adaptive Control project is to replace ad hoc, post-mortem performance optimization with an extensible, portable, and distributed...

  9. FPGA Implementation of Real-Time Ethernet for Motion Control

    Directory of Open Access Journals (Sweden)

    Chen Youdong

    2013-01-01

    Full Text Available This paper provides an applicable implementation of real-time Ethernet named CASNET, which modifies the Ethernet medium access control (MAC to achieve the real-time requirement for motion control. CASNET is the communication protocol used for motion control system. Verilog hardware description language (VHDL has been used in the MAC logic design. The designed MAC serves as one of the intellectual properties (IPs and is applicable to various industrial controllers. The interface of the physical layer is RJ45. The other layers have been implemented by using C programs. The real-time Ethernet has been implemented by using field programmable gate array (FPGA technology and the proposed solution has been tested through the cycle time, synchronization accuracy, and Wireshark testing.

  10. Real-time control for long ohmic alternate current discharges

    International Nuclear Information System (INIS)

    Carvalho, Ivo S.; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.; Gomes, Rui B.

    2014-01-01

    Highlights: • 40 Alternate plasma current (AC) semi-cycles without loss of ionization, more than 1 s of operation. • AC discharges automatic control: feedback loops, time-windows control strategy, goal oriented time-windows and exception handling. • Energy deposition and Carbon radiation evolution during the AC discharges. - Abstract: The ISTTOK tokamak has a long tradition on alternate plasma current (AC) discharges, but the old control system was limiting and lacked full system integration. In order to improve the AC discharges performance the ISTTOK fast control system was updated. This control system developed on site based on the Advanced Telecommunications Computing Architecture (ATCA) standard now integrates the information gathered by all the tokamak real-time diagnostics to produce an accurate observation of the plasma parameters. The real-time actuators were also integrated, allowing a Multiple Input Multiple Output (MIMO) control environment with several synchronization strategies available. The control system software was developed in C++ on top of a Linux system with the Multi-threaded Application Real-Time executor (MARTe) Framework to synchronize the real-time code execution under a 100μs control cycle. In addition, to simplify the discharge programming, a visual Human–Machine Interface (HMI) was also developed using the BaseLib2 libraries included in the MARTe Framework. This paper presents the ISTTOK control system and the optimizations that extended the AC current discharges duration to more than 1 s, corresponding to 40 semi-cycles without apparent degradation of the plasma parameters. This upgrade allows ISTTOK to be used as a low-cost material testing facility with long time exposures to nuclear fusion relevant plasmas, comparable (in duration) with medium size tokamaks

  11. Real-time control for long ohmic alternate current discharges

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.; Gomes, Rui B.

    2014-05-15

    Highlights: • 40 Alternate plasma current (AC) semi-cycles without loss of ionization, more than 1 s of operation. • AC discharges automatic control: feedback loops, time-windows control strategy, goal oriented time-windows and exception handling. • Energy deposition and Carbon radiation evolution during the AC discharges. - Abstract: The ISTTOK tokamak has a long tradition on alternate plasma current (AC) discharges, but the old control system was limiting and lacked full system integration. In order to improve the AC discharges performance the ISTTOK fast control system was updated. This control system developed on site based on the Advanced Telecommunications Computing Architecture (ATCA) standard now integrates the information gathered by all the tokamak real-time diagnostics to produce an accurate observation of the plasma parameters. The real-time actuators were also integrated, allowing a Multiple Input Multiple Output (MIMO) control environment with several synchronization strategies available. The control system software was developed in C++ on top of a Linux system with the Multi-threaded Application Real-Time executor (MARTe) Framework to synchronize the real-time code execution under a 100μs control cycle. In addition, to simplify the discharge programming, a visual Human–Machine Interface (HMI) was also developed using the BaseLib2 libraries included in the MARTe Framework. This paper presents the ISTTOK control system and the optimizations that extended the AC current discharges duration to more than 1 s, corresponding to 40 semi-cycles without apparent degradation of the plasma parameters. This upgrade allows ISTTOK to be used as a low-cost material testing facility with long time exposures to nuclear fusion relevant plasmas, comparable (in duration) with medium size tokamaks.

  12. Finite-Time Reentry Attitude Control Using Time-Varying Sliding Mode and Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Xuzhong Wu

    2015-01-01

    Full Text Available This paper presents the finite-time attitude control problem for reentry vehicle with redundant actuators in consideration of planet uncertainties and external disturbances. Firstly, feedback linearization technique is used to cancel the nonlinearities of equations of motion to construct a basic mode for attitude controller. Secondly, two kinds of time-varying sliding mode control methods with disturbance observer are integrated with the basic mode in order to enhance the control performance and system robustness. One method is designed based on boundary layer technique and the other is a novel second-order sliding model control method. The finite-time stability analyses of both resultant closed-loop systems are carried out. Furthermore, after attitude controller produces the torque commands, an optimization control allocation approach is introduced to allocate them into aerodynamic surface deflections and on-off reaction control system thrusts. Finally, the numerical simulation results demonstrate that both of the time-varying sliding mode control methods are robust to uncertainties and disturbances without chattering phenomenon. Moreover, the proposed second-order sliding mode control method possesses better control accuracy.

  13. The evolution of real-time control systems at JET

    Energy Technology Data Exchange (ETDEWEB)

    Goodyear, A.; Dorling, S.; Felton, R

    2001-07-01

    Real-time feedback control of the JET experiment is based upon a collection of diagnostics providing signals which are processed by various controllers that manipulate actuator parameters for plasma current, shape and heating. The real-time data network (RTDN) connects the diagnostic, controller and actuator systems to form a flexible feedback and protection system for plasma monitoring and control. The controllers are mainly VME systems based on the Motorola 680X0 (68K) processor with some computationally intensive systems utilising Texas Instruments TMS320C40 (C40) digital signal processors (DSP), though lately there has been a move towards PowerPC 750 based processors. The majority of 68K VME systems use VxWorks, a hard real time operating system. There is an ongoing requirement to improve the efficiency of the real-time control systems at JET. This is driven by a desire to either add more input signals, reduce the feedback cycle time or increase algorithm complexity. New technology has a major role to play in the upgrade of the real-time control systems but the novel redeployment of existing equipment can also be used to enhance performance. This paper examines the configuration of existing systems, both hardware and software, and how new technology can be gradually integrated without jeopardising the current functionality. The adoption of Asynchronous Transfer Mode (ATM) as the connection medium for the RTDN is key to the evolutional development of the control systems. The ATM network is extremely flexible to configure and benefits from low message latency and deterministic delivery time, essential properties for a real-time network. (author)

  14. Results of antiretroviral treatment interruption and intensification in advanced multi-drug resistant HIV infection from the OPTIMA trial.

    Directory of Open Access Journals (Sweden)

    Mark Holodniy

    2011-03-01

    Full Text Available Guidance is needed on best medical management for advanced HIV disease with multidrug resistance (MDR and limited retreatment options. We assessed two novel antiretroviral (ARV treatment approaches in this setting.We conducted a 2×2 factorial randomized open label controlled trial in patients with a CD4 count≤300 cells/µl who had ARV treatment (ART failure requiring retreatment, to two options (a re-treatment with either standard (≤4 ARVs or intensive (≥5 ARVs ART and b either treatment starting immediately or after a 12-week monitored ART interruption. Primary outcome was time to developing a first AIDS-defining event (ADE or death from any cause. Analysis was by intention to treat. From 2001 to 2006, 368 patients were randomized. At baseline, mean age was 48 years, 2% were women, median CD4 count was 106/µl, mean viral load was 4.74 log(10 copies/ml, and 59% had a prior AIDS diagnosis. Median follow-up was 4.0 years in 1249 person-years of observation. There were no statistically significant differences in the primary composite outcome of ADE or death between re-treatment options of standard versus intensive ART (hazard ratio 1.17; CI 0.86-1.59, or between immediate retreatment initiation versus interruption before re-treatment (hazard ratio 0.93; CI 0.68-1.30, or in the rate of non-HIV associated serious adverse events between re-treatment options.We did not observe clinical benefit or harm assessed by the primary outcome in this largest and longest trial exploring both ART interruption and intensification in advanced MDR HIV infection with poor retreatment options.Clinicaltrials.gov NCT00050089.

  15. Interrupter and hybrid-switch testing for fusion devices

    International Nuclear Information System (INIS)

    Parsons, W.M.; Warren, R.W.; Honig, E.M.; Lindsay, J.D.G.; Bellamo, P.; Cassel, R.L.

    1979-01-01

    This paper discusses recent and ongoing switch testing for fusion devices. The first part describes testing for the TFTR ohmic-heating circuit. In this set of tests, which simulated the stresses produced during a plasma initiation pulse, circuit breakers were required to interrupt a current of 24 kA with an associated recovery voltage of 25 kV. Two interrupter systems were tested for over 1000 operations each, and both appear to satisfy TFTR requirements. The second part discusses hybrid-switch development for superconducting coil protection. These switching systems must be capable of carrying large currents on a continuous basis as well as performing interruption duties. The third part presents preliminary results on an early-counterpulse technique applied to vacuum interrupters. Implementation of this technique has resulted in large increases in interruptible current as well as a marked reduction in contact erosion

  16. Effects of interruption of irradiation on Harwell Red Perspex (PMMA)

    International Nuclear Information System (INIS)

    Khayet Tebourbi, Mohamed anouar abdelaziz

    2010-01-01

    Harwell Red Perspex PMMA (Polymethylmethacrylate) is a dosimeter very much used in the industrial treatments by Radiations ionizing. The purpose of this work is to test the response of this dosimeter for radiation processes having undergone one or more interruptions. This experimental study based on the development of a factorial experimental design on two levels showed that the response of this dosimeter increases for the interrupted treatments. The value of the estimated amount of response increase is all the more significant as the temperature during the interruption is high. Also it made possible to determine a mathematical model binding the value of the amount posted to the factors of influence: Temperature, target amount, a number of interruptions and duration of each interruption.

  17. Real-time control environment for the RFX experiment

    International Nuclear Information System (INIS)

    Barana, O.; Cavinato, M.; Luchetta, A.; Manduchi, G.; Taliercio, C.

    2005-01-01

    A comprehensive set of control schemes can be presently implemented on RFX due to the enhanced load assembly and renewed power supply system. The schemes include: plasma equilibrium control and resistive wall mode stabilization, aiming at controlling actively the discharge when the passive action of the shell vanishes; the rotation of the localised helical deformation to minimize the enhanced plasma-wall interaction; the MHD mode control and the 'intelligent shell', aiming at achieving a better comprehension of the underlying physics. To the purpose, an integrated, distributed, digital system has been developed consisting of a set of computing nodes. Each node can act either as pre-processing or control station, the former acquiring raw data and computing intermediate control parameters, the latter executing control algorithms and driving the power amplifiers. An overview of the system architecture is presented in the paper with reference to the software real-time environment providing both basic functions, such as data read-out and real-time communication, and useful tools to program control algorithms, to perform simulations and to commission the system. To simulate the control schemes, the real-time environment is extended to include a so called 'simulation mode', in which the real-time nodes exchange their input/output signals with one station running a suitable model of the experiment, for instance the two dimensional FEM code MAXFEA in the case of the equilibrium control. In this way the control system can be tested offline and the time needed for the commissioning of algorithms reduced

  18. The hybrid UNIX controller for real-time data acquisition

    International Nuclear Information System (INIS)

    Huesman, R.H.; Klein, G.J.; Fleming, T.K.

    1996-01-01

    The authors describe a hybrid data acquisition architecture integrating a conventional UNIX workstation with CAMAC-based real-time hardware. The system combines the high-level programming simplicity and user interface of a UNIX workstation with the low-level timing control available from conventional real-time hardware. They detail this architecture as it has been implemented for control of the Donner 600-Crystal Positron Tomograph (PET600). Low-level data acquisition is carried out in this system using eight LeCroy 3588 histogrammers, which together after derandomization, acquire events at rates up to 4 MHz, and two dedicated Motorola 6809 microprocessors, which arbitrate fine timing control during acquisition. A SUN Microsystems UNIX workstation is used for high-level control, allowing an easily extensible user interface in an X-Windows environment, as well as real-time communications to the low-level acquisition units. Communication between the high- and low-level units is carried out via a Jorway 73A SCSI-CAMAC crate controller and a serial interface. For this application, the hybrid configuration segments low from high-level control for ease of maintenance and provided a low-cost upgrade from dated high-level control hardware

  19. An adaptive robust controller for time delay maglev transportation systems

    Science.gov (United States)

    Milani, Reza Hamidi; Zarabadipour, Hassan; Shahnazi, Reza

    2012-12-01

    For engineering systems, uncertainties and time delays are two important issues that must be considered in control design. Uncertainties are often encountered in various dynamical systems due to modeling errors, measurement noises, linearization and approximations. Time delays have always been among the most difficult problems encountered in process control. In practical applications of feedback control, time delay arises frequently and can severely degrade closed-loop system performance and in some cases, drives the system to instability. Therefore, stability analysis and controller synthesis for uncertain nonlinear time-delay systems are important both in theory and in practice and many analytical techniques have been developed using delay-dependent Lyapunov function. In the past decade the magnetic and levitation (maglev) transportation system as a new system with high functionality has been the focus of numerous studies. However, maglev transportation systems are highly nonlinear and thus designing controller for those are challenging. The main topic of this paper is to design an adaptive robust controller for maglev transportation systems with time-delay, parametric uncertainties and external disturbances. In this paper, an adaptive robust control (ARC) is designed for this purpose. It should be noted that the adaptive gain is derived from Lyapunov-Krasovskii synthesis method, therefore asymptotic stability is guaranteed.

  20. Time-optimal feedback control for linear systems

    International Nuclear Information System (INIS)

    Mirica, S.

    1976-01-01

    The paper deals with the results of qualitative investigations of the time-optimal feedback control for linear systems with constant coefficients. In the first section, after some definitions and notations, two examples are given and it is shown that even the time-optimal control problem for linear systems with constant coefficients which looked like ''completely solved'' requires a further qualitative investigation of the stability to ''permanent perturbations'' of optimal feedback control. In the second section some basic results of the linear time-optimal control problem are reviewed. The third section deals with the definition of Boltyanskii's ''regular synthesis'' and its connection to Filippov's theory of right-hand side discontinuous differential equations. In the fourth section a theorem is proved concerning the stability to perturbations of time-optimal feedback control for linear systems with scalar control. In the last two sections it is proved that, if the matrix which defines the system has only real eigenvalues or is three-dimensional, the time-optimal feedback control defines a regular synthesis and therefore is stable to perturbations. (author)

  1. Infrared wireless data transfer for real-time motion control

    NARCIS (Netherlands)

    Gajdusek, M.; Overboom, T.T.; Damen, A.A.H.; Bosch, van den P.P.J.

    2009-01-01

    In this paper several wireless solution are compared for their suitability for real-time control of a fast motion system. From the comparison, Very Fast Infrared (VFIR) communication link has been found to be an attractive solution for presented wirelessly controlled manipulator. Because standard

  2. Testing power system controllers by real-time simulation

    DEFF Research Database (Denmark)

    Venne, Philippe; Guillaud, Xavier; Sirois, Frédéric

    2007-01-01

    In this paper, we present a number of state-of-the art methods for testing power system controllers based on the use of a real-time power system simulator. After introducing Hypersim, we list and discuss the different means of connection between the controller under tests and the power system...

  3. Auxiliary controller for time-to-digital converter module readout

    International Nuclear Information System (INIS)

    Ermolin, Yu.V.

    1992-01-01

    The KD-225 auxiliary controller for time-to-digital converter module readout in the SUMMA crate is described. After readout and preliminary processing the data are written in the P-140 buffer memory module. The controller is used in the FODS-2 experimental setup data acquisition system. 12 refs.; 1 fig

  4. Real time control of the SSC string magnets

    International Nuclear Information System (INIS)

    Calvo, O.; Flora, R.; MacPherson, M.

    1987-01-01

    The system described in this paper, called SECAR, was designed to control the excitation of a test string of magnets for the proposed Superconducting Super Collider (SSC) and will be used to upgrade the present Tevatron Excitation, Control and Regulation (TECAR) hardware and software. It resides in a VME orate and is controlled by a 68020/68881 based CPU running the application software under a real time operating system named VRTX

  5. Guaranteed cost control of time-delay chaotic systems

    International Nuclear Information System (INIS)

    Park, Ju H.; Kwon, O.M.

    2006-01-01

    This article studies a guaranteed cost control problem for a class of time-delay chaotic systems. Attention is focused on the design of memory state feedback controllers such that the resulting closed-loop system is asymptotically stable and an adequate level of performance is also guaranteed. Using the Lyapunov method and LMI (linear matrix inequality) framework, two criteria for the existence of the controller are derived in terms of LMIs. A numerical example is given to illustrate the proposed method

  6. Increased short-term risk of thrombo-embolism or death after interruption of warfarin treatment in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Raunsø, Jakob; Selmer, Christian; Olesen, Jonas Bjerring

    2012-01-01

    AimsIt is presently unknown whether patients with atrial fibrillation (AF) are at increased risk of thrombo-embolic adverse events after interruption of warfarin treatment. The purpose of this study was to assess the risk and timing of thrombo-embolism after warfarin treatment interruption.Method...

  7. Assessment of variations in control of asthma over time.

    Science.gov (United States)

    Combescure, C; Chanez, P; Saint-Pierre, P; Daurès, J P; Proudhon, H; Godard, P

    2003-08-01

    Control and severity of asthma are two different but complementary concepts. The severity of asthma could influence the control over time. The aim of this study was to demonstrate this relationship. A total 365 patients with persistent asthma (severity) were enrolled and followed-up prospectively. Data were analysed using a continuous time homogeneous Markov model of the natural history of asthma. Control of asthma was defined according to three health states which were qualified: optimal, suboptimal and unacceptable control (states 1, 2 and 3). Transition forces (denoted lambda(ij) from state i to state j) and transition probabilities between control states were assessed and the results stratified by asthma severity were compared. Models were validated by comparing expected and observed numbers of patients in the different states. Transition probabilities stabilised between 100-250 days and more rapidly in patients with mild-to-moderate asthma. Patients with mild-to-moderate asthma in suboptimal or unacceptable control had a high probability of transition directly to optimal control. Patients with severe asthma had a tendency to remain in unacceptable control. A Markov model is a useful tool to model the control of asthma over time. Severity modified clearly the health states. It could be used to compare the performance of different approaches to asthma management.

  8. Time-delay effects and simplified control fields in quantum Lyapunov control

    International Nuclear Information System (INIS)

    Yi, X X; Wu, S L; Wu, Chunfeng; Feng, X L; Oh, C H

    2011-01-01

    Lyapunov-based quantum control has the advantage that it is free from the measurement-induced decoherence and it includes the instantaneous information of the system in the control. The Lyapunov control is often confronted with time delay in the control fields and difficulty in practical implementations of the control. In this paper, we study the effect of time delay on the Lyapunov control and explore the possibility of replacing the control field with a pulse train or a bang-bang signal. The efficiency of the Lyapunov control is also presented through examining the convergence time of the system. These results suggest that the Lyapunov control is robust against time delay, easy to realize and effective for high-dimensional quantum systems.

  9. A continuous-time control model on production planning network ...

    African Journals Online (AJOL)

    A continuous-time control model on production planning network. DEA Omorogbe, MIU Okunsebor. Abstract. In this paper, we give a slightly detailed review of Graves and Hollywood model on constant inventory tactical planning model for a job shop. The limitations of this model are pointed out and a continuous time ...

  10. Real-Time Plasma Control Tools for Advanced Tokamak Operation

    International Nuclear Information System (INIS)

    Varandas, C. A. F.; Sousa, J.; Rodrigues, A. P.; Carvalho, B. B.; Fernandes, H.; Batista, A. J.; Cruz, N.; Combo, A.; Pereira, R. C.

    2006-01-01

    Real-time control will play an important role in the operation and scientific exploitation of the new generation fusion devices. This paper summarizes the real-time systems and diagnostics developed by the Portuguese Fusion Euratom Association based on digital signal processors and field programmable gate arrays

  11. Controlling traffic jams by time modulating the safety distance

    DEFF Research Database (Denmark)

    Gaididei, Yu B.; Gorria, C.; Berkemer, R.

    2013-01-01

    The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case....

  12. Real time control of plasmas and ECRH systems on TCV

    NARCIS (Netherlands)

    Paley, J.I.; Berrino, J.; Coda, S.; Cruz, N.; Duval, B.P.; Felici, F.; Goodman, T.P.; Martin, Y.; Moret, J.-M.; Piras, F.; Rodriques, A.P.; Santos, B.; Varandas, C.A.F.

    2009-01-01

    Developments in the real time control hardware on Tokamak Configuration Variable (TCV) coupled with the flexibility of plasma shaping and electron cyclotron (EC) heating and current drive actuators are opening many opportunities to perform real time experiments and develop algorithms and methods for

  13. Time-lapse controlled-source electromagnetics using interferometry

    NARCIS (Netherlands)

    Hunziker, J.W.; Slob, E.C.; Wapenaar, C.P.A.

    In time-lapse controlled-source electromagnetics, it is crucial that the source and the receivers are positioned at exactly the same location at all times of measurement. We use interferometry by multidimensional deconvolution (MDD) to overcome problems in repeatability of the source location.

  14. Simulation of Simple Controlled Processes with Dead-Time.

    Science.gov (United States)

    Watson, Keith R.; And Others

    1985-01-01

    The determination of closed-loop response of processes containing dead-time is typically not covered in undergraduate process control, possibly because the solution by Laplace transforms requires the use of Pade approximation for dead-time, which makes the procedure lengthy and tedious. A computer-aided method is described which simplifies the…

  15. Advanced Map For Real-Time Process Control

    Science.gov (United States)

    Shiobara, Yasuhisa; Matsudaira, Takayuki; Sashida, Yoshio; Chikuma, Makoto

    1987-10-01

    MAP, a communications protocol for factory automation proposed by General Motors [1], has been accepted by users throughout the world and is rapidly becoming a user standard. In fact, it is now a LAN standard for factory automation. MAP is intended to interconnect different devices, such as computers and programmable devices, made by different manufacturers, enabling them to exchange information. It is based on the OSI intercomputer com-munications protocol standard under development by the ISO. With progress and standardization, MAP is being investigated for application to process control fields other than factory automation [2]. The transmission response time of the network system and centralized management of data exchanged with various devices for distributed control are import-ant in the case of a real-time process control with programmable controllers, computers, and instruments connected to a LAN system. MAP/EPA and MINI MAP aim at reduced overhead in protocol processing and enhanced transmission response. If applied to real-time process control, a protocol based on point-to-point and request-response transactions limits throughput and transmission response. This paper describes an advanced MAP LAN system applied to real-time process control by adding a new data transmission control that performs multicasting communication voluntarily and periodically in the priority order of data to be exchanged.

  16. Predicting Time Series Outputs and Time-to-Failure for an Aircraft Controller Using Bayesian Modeling

    Science.gov (United States)

    He, Yuning

    2015-01-01

    Safety of unmanned aerial systems (UAS) is paramount, but the large number of dynamically changing controller parameters makes it hard to determine if the system is currently stable, and the time before loss of control if not. We propose a hierarchical statistical model using Treed Gaussian Processes to predict (i) whether a flight will be stable (success) or become unstable (failure), (ii) the time-to-failure if unstable, and (iii) time series outputs for flight variables. We first classify the current flight input into success or failure types, and then use separate models for each class to predict the time-to-failure and time series outputs. As different inputs may cause failures at different times, we have to model variable length output curves. We use a basis representation for curves and learn the mappings from input to basis coefficients. We demonstrate the effectiveness of our prediction methods on a NASA neuro-adaptive flight control system.

  17. Time scaling internal state predictive control of a solar plant

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.N. [DEE-FCT/UNL, Caparica (Portugal); Rato, L.M. [INESC-ID/University, Evora (Portugal); Lemos, J.M. [INESC-ID/IST, Lisboa (Portugal)

    2003-12-01

    The control of a distributed collector solar field is addressed in this work, exploiting the plant's transport characteristic. The plant is modeled by a hyperbolic type partial differential equation (PDE) where the transport speed is the manipulated flow, i.e. the controller output. The model has an external distributed source, which is the solar radiation captured along the collector, approximated to depend only of time. From the solution of the PDE, a linear discrete state space model is obtained by using time-scaling and the redefinition of the control input. This method allows overcoming the dependency of the time constants with the operating point. A model-based predictive adaptive controller is derived with the internal temperature distribution estimated with a state observer. Experimental results at the solar power plant are presented, illustrating the advantages of the approach under consideration. (author)

  18. Real time control of plasmas and ECRH systems on TCV

    International Nuclear Information System (INIS)

    Paley, J.I.; Berrino, J.; Coda, S.; Duval, B.P.; Felici, F.; Goodman, T.P.; Martin, Y.; Moret, J.M.; Piras, F.; Cruz, N.; Rodriques, A.P.; Santos, B.; Varandas, C.A.F.

    2009-01-01

    Developments in the real time control hardware on Tokamak a Configuration Variable (TCV) coupled with the flexibility of plasma shaping and electron cyclotron (EC) heating and current drive actuators are opening many opportunities to perform real time experiments and develop algorithms and methods for fusion applications. The ability to control magnetohydrodynamic instabilities is particularly important for achieving high performance fusion plasmas and EC is envisaged as a key actuator in maintaining high performance. We have successfully demonstrated control of the sawtooth instability using the EC launcher injection angle to modify the current profile around the q =1 surface. This paper presents an overview of recent real time control experiments on TCV, developments in the hardware and algorithms together with plans for the future.

  19. Application of Skype API to Control Working Time

    Directory of Open Access Journals (Sweden)

    Julian Vasilev

    2013-11-01

    Full Text Available The purpose of this article is to present an innovative approach to monitor and control working time. A special software program is developed by Delphi implementing Skype API functions. This article shows three different approaches to control working time using the Skype_API program. It automatically detects when an employee goes to his working place and when he leaves work. Moreover it can check periodically weather an employee is at work. The proposed ideas are written for the first time. They may be applied easily in many enterprises with very low costs.

  20. Model-Checking Real-Time Control Programs

    DEFF Research Database (Denmark)

    Iversen, T. K.; Kristoffersen, K. J.; Larsen, Kim Guldstrand

    2000-01-01

    In this paper, we present a method for automatic verification of real-time control programs running on LEGO(R) RCX(TM) bricks using the verification tool UPPALL. The control programs, consisting of a number of tasks running concurrently, are automatically translated into the mixed automata model...... of UPPAAL. The fixed scheduling algorithm used by the LEGO(R) RCX(TM) processor is modeled in UPPALL, and supply of similar (sufficient) timed automata models for the environment allows analysis of the overall real-time system using the tools of UPPALL. To illustrate our technique for sorting LEGO(R) bricks...

  1. Response times of operators in a control room

    International Nuclear Information System (INIS)

    Platz, O.; Rasmussen, J.; Skanborg, P.Z.

    1982-12-01

    A statistical analysis was made of operator response times recorded in the control room of a research reactor during the years 1972-1974. A homogeneity test revealed that the data consist of a mixture of populations. A small but statistically significant difference is found between day and night response times. Lognormal distributions are found to provide the best fit of the day and the night response times. (author)

  2. Adaptive control of discrete-time chaotic systems: a fuzzy control approach

    International Nuclear Information System (INIS)

    Feng Gang; Chen Guanrong

    2005-01-01

    This paper discusses adaptive control of a class of discrete-time chaotic systems from a fuzzy control approach. Using the T-S model of discrete-time chaotic systems, an adaptive control algorithm is developed based on some conventional adaptive control techniques. The resulting adaptively controlled chaotic system is shown to be globally stable, and its robustness is discussed. A simulation example of the chaotic Henon map control is finally presented, to illustrate an application and the performance of the proposed control algorithm

  3. Engine control system having pressure-based timing

    Science.gov (United States)

    Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

    2011-10-04

    A control system for an engine having a first cylinder and a second cylinder is disclosed having a first engine valve movable to regulate a fluid flow of the first cylinder and a first actuator associated with the first engine valve. The control system also has a second engine valve movable to regulate a fluid flow of the second cylinder and a sensor configured to generate a signal indicative of a pressure within the first cylinder. The control system also has a controller that is in communication with the first actuator and the sensor. The controller is configured to compare the pressure within the first cylinder with a desired pressure and selectively regulate the first actuator to adjust a timing of the first engine valve independently of the timing of the second engine valve based on the comparison.

  4. Optimal control for parabolic-hyperbolic system with time delay

    International Nuclear Information System (INIS)

    Kowalewski, A.

    1985-07-01

    In this paper we consider an optimal control problem for a system described by a linear partial differential equation of the parabolic-hyperbolic type with time delay in the state. The right-hand side of this equation and the initial conditions are not continuous functions usually, but they are measurable functions belonging to L 2 or Lsup(infinity) spaces. Therefore, the solution of this equation is given by a certain Sobolev space. The time delay in the state is constant, but it can be also a function of time. The control time T is fixed in our problem. Making use of the Milutin-Dubovicki theorem, necessary and sufficient conditions of optimality with the quadratic performance functional and constrained control are derived for the Dirichlet problem. The flow chart of the algorithm which can be used in the numerical solving of certain optimization problems for distributed systems is also presented. (author)

  5. Real time equilibrium reconstruction for tokamak discharge control

    International Nuclear Information System (INIS)

    Ferron, J.R.; Walker, M.L.; Lao, L.L.; St John, H.E.; Humphreys, D.A.; Leuer, J.A.

    1998-01-01

    A practical method for performing a tokamak equilibrium reconstruction in real time for arbitrary time varying discharge shapes and current profiles is described. An approximate solution to the Grad-Shafranov equilibrium relation is found which best fits the diagnostic measurements. Thus, a solution for the spatial distribution of poloidal flux and toroidal current density is available in real time that is consistent with plasma force balance, allowing accurate evaluation of parameters such as discharge shape and safety factor profile. The equilibrium solutions are produced at a rate sufficient for discharge control. This equilibrium reconstruction algorithm has been implemented on the digital plasma control system for the DIII-D tokamak. The first application of real time equilibrium reconstruction to discharge shape control is described. (author)

  6. Engine control system having fuel-based timing

    Science.gov (United States)

    Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

    2012-04-03

    A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a sensor configured to generate a signal indicative of an amount of an air/fuel mixture remaining within the cylinder after completion of a first combustion event and a controller in communication with the actuator and the sensor. The controller may be configured to compare the amount with a desired amount, and to selectively regulate the actuator to adjust a timing of the engine valve associated with a subsequent combustion event based on the comparison.

  7. Direct-Current Forced Interruption and Breaking Performance of Spiral-Type Contacts in Aero Applications

    Directory of Open Access Journals (Sweden)

    Wenlei Huo

    2017-05-01

    Full Text Available This paper analyses the transient characteristics and breaking performance of direct-current (DC forced-interruption vacuum interrupters in 270 V power-supply systems. Three stages are identified in forced interruption: the DC-arcing stage, current-commutation stage, and voltage-recovery stage. During the current-commutation stage, the reverse peak-current coefficient k, which is a key design factor, is used to calculate the rate of current at zero-crossing (di/dt. MATLAB/Simulink simulation models are established to obtain the transient characteristics influenced by the forced-commutation branch parameters and the coefficient k. To study the breaking performance of spiral-type contacts, experiments are conducted for different contact materials and arcing times for currents less than 3.5 kA. During the DC-arcing stage, a locally intensive burning arc is observed in the CuW80 contact; however, it is not observed in the CuCr50 contact. On examining the re-ignition interruption results of the CuW80 contact, the intensive burning arc is found to be positioned within a possible re-ignition region. When the arcing time is longer than 1 ms, the intensive burning arc occurs and affects the breaking performance of the spiral-type contacts. If the DC-arcing stage is prolonged, the total arcing energy increases, which leads to a lower breaking capacity.

  8. Developing infrared array controller with software real time operating system

    Science.gov (United States)

    Sako, Shigeyuki; Miyata, Takashi; Nakamura, Tomohiko; Motohara, Kentaro; Uchimoto, Yuka Katsuno; Onaka, Takashi; Kataza, Hirokazu

    2008-07-01

    Real-time capabilities are required for a controller of a large format array to reduce a dead-time attributed by readout and data transfer. The real-time processing has been achieved by dedicated processors including DSP, CPLD, and FPGA devices. However, the dedicated processors have problems with memory resources, inflexibility, and high cost. Meanwhile, a recent PC has sufficient resources of CPUs and memories to control the infrared array and to process a large amount of frame data in real-time. In this study, we have developed an infrared array controller with a software real-time operating system (RTOS) instead of the dedicated processors. A Linux PC equipped with a RTAI extension and a dual-core CPU is used as a main computer, and one of the CPU cores is allocated to the real-time processing. A digital I/O board with DMA functions is used for an I/O interface. The signal-processing cores are integrated in the OS kernel as a real-time driver module, which is composed of two virtual devices of the clock processor and the frame processor tasks. The array controller with the RTOS realizes complicated operations easily, flexibly, and at a low cost.

  9. Identification of Time-Varying Pilot Control Behavior in Multi-Axis Control Tasks

    Science.gov (United States)

    Zaal, Peter M. T.; Sweet, Barbara T.

    2012-01-01

    Recent developments in fly-by-wire control architectures for rotorcraft have introduced new interest in the identification of time-varying pilot control behavior in multi-axis control tasks. In this paper a maximum likelihood estimation method is used to estimate the parameters of a pilot model with time-dependent sigmoid functions to characterize time-varying human control behavior. An experiment was performed by 9 general aviation pilots who had to perform a simultaneous roll and pitch control task with time-varying aircraft dynamics. In 8 different conditions, the axis containing the time-varying dynamics and the growth factor of the dynamics were varied, allowing for an analysis of the performance of the estimation method when estimating time-dependent parameter functions. In addition, a detailed analysis of pilots adaptation to the time-varying aircraft dynamics in both the roll and pitch axes could be performed. Pilot control behavior in both axes was significantly affected by the time-varying aircraft dynamics in roll and pitch, and by the growth factor. The main effect was found in the axis that contained the time-varying dynamics. However, pilot control behavior also changed over time in the axis not containing the time-varying aircraft dynamics. This indicates that some cross coupling exists in the perception and control processes between the roll and pitch axes.

  10. Controller synthesis for dynamic hierarchical real-time plants using timed automata

    DEFF Research Database (Denmark)

    Bin Waez, Md Tawhid; Wasowski, Andrzej; Dingel, Juergen

    2017-01-01

    We use timed I/O automata based timed games to synthesize task-level reconfiguration services for cost-effective fault tolerance in a case study. The case study shows that state-space explosion is a severe problem for timed games. By applying suitable abstractions, we dramatically improve...... the scalability. However, timed I/O automata do not facilitate algorithmic abstraction generation techniques. The case study motivates the development of timed process automata to improve modeling and analysis for controller synthesis of time-critical plants which can be hierarchical and dynamic. The model offers...

  11. Time-division-multiplex control scheme for voltage multiplier rectifiers

    Directory of Open Access Journals (Sweden)

    Bin-Han Liu

    2017-03-01

    Full Text Available A voltage multiplier rectifier with a novel time-division-multiplexing (TDM control scheme for high step-up converters is proposed in this study. In the proposed TDM control scheme, two full-wave voltage doubler rectifiers can be combined to realise a voltage quadrupler rectifier. The proposed voltage quadrupler rectifier can reduce transformer turn ratio and transformer size for high step-up converters and also reduce voltage stress for the output capacitors and rectifier diodes. An N-times voltage rectifier can be straightforwardly produced by extending the concepts from the proposed TDM control scheme. A phase-shift full-bridge (PSFB converter is adopted in the primary side of the proposed voltage quadrupler rectifier to construct a PSFB quadrupler converter. Experimental results for the PSFB quadrupler converter demonstrate the performance of the proposed TDM control scheme for voltage quadrupler rectifiers. An 8-times voltage rectifier is simulated to determine the validity of extending the proposed TDM control scheme to realise an N-times voltage rectifier. Experimental and simulation results show that the proposed TDM control scheme has great potential to be used in high step-up converters.

  12. Measurement and control of cement set times in waste solidification

    International Nuclear Information System (INIS)

    Stone, J.A.; d'Entremont, P.D.

    1976-09-01

    Fixation of radioactive waste in concrete was investigated on laboratory scale. Some cement formulations containing simulated or actual sludges from the Savannah River Plant had set times that would be too short for reliable handling in plant equipment. Set times could be controlled by use of excess water, but the concrete forms produced had inferior strength. A commercial organic retarder was found to be effective for increasing set times of cement-sludge formulations. However, the dosage of retarder required to control set times of high-alumina cement formulations was 1.0 to 1.5 wt percent of dry solids, which is 5 to 10 times the normal dosage for Portland cements. Data were obtained to predict the optimum content of retarder and water

  13. Upgrade of the COMPASS tokamak real-time control system

    Energy Technology Data Exchange (ETDEWEB)

    Janky, F., E-mail: filip.janky.work@gmail.com [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 18200 Prague (Czech Republic); Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague (Czech Republic); Havlicek, J. [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 18200 Prague (Czech Republic); Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague (Czech Republic); Batista, A.J.N. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal); Kudlacek, O.; Seidl, J. [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 18200 Prague (Czech Republic); Neto, A.C. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal); Pipek, J.; Hron, M. [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 18200 Prague (Czech Republic); Mikulin, O. [Institute of Plasma Physics, AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, 18200 Prague (Czech Republic); Czech Technical University, Faculty of Nuclear Sciences and Physical Engineering, V Holesovickach 2, 18000 Prague (Czech Republic); and others

    2014-03-15

    Highlights: • An upgrade of the COMPASS real-time system has been made to generally improve the plasma performance. • Stability of discharges in SNT configuration has been increased. • Plasma flat-top phase length has been extended. • Central solenoid protection has been developed. • Plasma position estimation has been improved. - Abstract: The COMPASS plasma control system is based on the MARTe real-time framework. Thanks to MARTe modularity and flexibility new algorithms have been developed for plasma diagnostic (plasma position calculation), control (shaping field control), and protection systems (central solenoid protection). Moreover, the MARTe framework itself was modified to broaden the communication capabilities via Aurora. This paper presents the recent upgrades and improvements made to the COMPASS real-time plasma control system, focusing on the issues related to precision of the real-time calculations, and discussing the improvements in terms of discharge parameters and stability. In particular, the new real-time system has given the possibility to analyze and to minimize the transport delays of each control loop.

  14. A time-varying extremum-seeking control approach for discrete-time systems with application to model predictive control

    NARCIS (Netherlands)

    Guay, M.; Beerens, R.; Nijmeijer, H.

    2014-01-01

    This paper considers the solution of a real-time optimization problem using adaptive extremum seeking control for a class of unknown discrete-time nonlinear systems. It is assumed that the equations describing the dynamics of the nonlinear system and the cost function to be minimized are unknown and

  15. Real-time control of internal transport barriers in JET

    Energy Technology Data Exchange (ETDEWEB)

    Mazon, D.; Litaudon, X.; Moreau, D. [Association Euratom-CEA, CEA Cadarache, St. Paul lez Durance (France)] [and others

    2002-07-01

    We present the results of recent experiments related to real-time control of internal transport barriers (ITBs) in JET. Using a simple criterion to characterize the ITB existence, location and strength, we have successfully controlled for the first time the radial electron temperature profile within the ITB. The dimensionless variable used in the real-time algorithm - ratio of the ion gyro-radius to the local gradient scale length of the electron temperature - is a measure of the normalized electron temperature gradient and characterizes satisfactorily the main ITB features with a relatively low computational cost. We show several examples of control of this variable in various experimental conditions of toroidal field and plasma current, using different heating systems as control actuators. We also present a double-loop feedback scheme where both the global neutron rate from D-D reactions and the ITB strength are controlled simultaneously. In this case the ITB is sustained in a fully non-inductive current drive regime during several seconds. With the proposed control method, disruptions are avoided by holding the plasma performance at a prescribed target and this opens the route towards stationary operation of tokamak plasmas with ITBs. Initial results suggest that the additional control of the current profile is an important issue for achieving steady-state operation, in particular in the triggering and the sustainment of the ITB. (author)

  16. Time-dependent switched discrete-time linear systems control and filtering

    CERN Document Server

    Zhang, Lixian; Shi, Peng; Lu, Qiugang

    2016-01-01

    This book focuses on the basic control and filtering synthesis problems for discrete-time switched linear systems under time-dependent switching signals. Chapter 1, as an introduction of the book, gives the backgrounds and motivations of switched systems, the definitions of the typical time-dependent switching signals, the differences and links to other types of systems with hybrid characteristics and a literature review mainly on the control and filtering for the underlying systems. By summarizing the multiple Lyapunov-like functions (MLFs) approach in which different requirements on comparisons of Lyapunov function values at switching instants, a series of methodologies are developed for the issues on stability and stabilization, and l2-gain performance or tube-based robustness for l∞ disturbance, respectively, in Chapters 2 and 3. Chapters 4 and 5 are devoted to the control and filtering problems for the time-dependent switched linear systems with either polytopic uncertainties or measurable time-varying...

  17. [The utility of the interrupter technique in pediatric asthma].

    Science.gov (United States)

    Iimura, Akiko; Yoshihara, Shigemi; Arisaka, Osamu

    2002-11-01

    Interrupter respiratory resistance (Rint) is a new lung function test for measuring airway resistance. We investigated the utility of the Rint lung function test in pediatric patients with asthma. Thirty seven asthmatic patients with mild or moderate asthma attack (asthma group) and 9 healthy children (control group) were enrolled in the study, and the utility of the Ring test was compared with that of the PEF lung function test. Rint and PEF were measured after the inhalation of saline or beta(2) stimulant, and the values for the asthma and control groups were compared. The rint and PEF values did not change after the inhalation of saline, but both values improved after the inhalation of beta(2) stimulant in the asthma group. In the control group, the PEF and Rint values measured after saline or beta(2) stimulant were not significantly different. Rint measurements may be more useful than PEF tests for evaluating therapeutic responses to mild asthma attacks in children. These findings suggest that Rint is a useful respiratory function test for evaluating children with asthma.

  18. Measuring the relationship between interruptions, multitasking and prescribing errors in an emergency department: a study protocol.

    Science.gov (United States)

    Raban, Magdalena Z; Walter, Scott R; Douglas, Heather E; Strumpman, Dana; Mackenzie, John; Westbrook, Johanna I

    2015-10-13

    Interruptions and multitasking are frequent in clinical settings, and have been shown in the cognitive psychology literature to affect performance, increasing the risk of error. However, comparatively less is known about their impact on errors in clinical work. This study will assess the relationship between prescribing errors, interruptions and multitasking in an emergency department (ED) using direct observations and chart review. The study will be conducted in an ED of a 440-bed teaching hospital in Sydney, Australia. Doctors will be shadowed at proximity by observers for 2 h time intervals while they are working on day shift (between 0800 and 1800). Time stamped data on tasks, interruptions and multitasking will be recorded on a handheld computer using the validated Work Observation Method by Activity Timing (WOMBAT) tool. The prompts leading to interruptions and multitasking will also be recorded. When doctors prescribe medication, type of chart and chart sections written on, along with the patient's medical record number (MRN) will be recorded. A clinical pharmacist will access patient records and assess the medication orders for prescribing errors. The prescribing error rate will be calculated per prescribing task and is defined as the number of errors divided by the number of medication orders written during the prescribing task. The association between prescribing error rates, and rates of prompts, interruptions and multitasking will be assessed using statistical modelling. Ethics approval has been obtained from the hospital research ethics committee. Eligible doctors will be provided with written information sheets and written consent will be obtained if they agree to participate. Doctor details and MRNs will be kept separate from the data on prescribing errors, and will not appear in the final data set for analysis. Study results will be disseminated in publications and feedback to the ED. Published by the BMJ Publishing Group Limited. For permission

  19. Finite-Time and Fixed-Time Cluster Synchronization With or Without Pinning Control.

    Science.gov (United States)

    Liu, Xiwei; Chen, Tianping

    2018-01-01

    In this paper, the finite-time and fixed-time cluster synchronization problem for complex networks with or without pinning control are discussed. Finite-time (or fixed-time) synchronization has been a hot topic in recent years, which means that the network can achieve synchronization in finite-time, and the settling time depends on the initial values for finite-time synchronization (or the settling time is bounded by a constant for any initial values for fixed-time synchronization). To realize the finite-time and fixed-time cluster synchronization, some simple distributed protocols with or without pinning control are designed and the effectiveness is rigorously proved. Several sufficient criteria are also obtained to clarify the effects of coupling terms for finite-time and fixed-time cluster synchronization. Especially, when the cluster number is one, the cluster synchronization becomes the complete synchronization problem; when the network has only one node, the coupling term between nodes will disappear, and the synchronization problem becomes the simplest master-slave case, which also includes the stability problem for nonlinear systems like neural networks. All these cases are also discussed. Finally, numerical simulations are presented to demonstrate the correctness of obtained theoretical results.

  20. Control of photon storage time using phase locking.

    Science.gov (United States)

    Ham, Byoung S

    2010-01-18

    A photon echo storage-time extension protocol is presented by using a phase locking method in a three-level backward propagation scheme, where phase locking serves as a conditional stopper of the rephasing process in conventional two-pulse photon echoes. The backward propagation scheme solves the critical problems of extremely low retrieval efficiency and pi rephasing pulse-caused spontaneous emission noise in photon echo based quantum memories. The physics of the storage time extension lies in the imminent population transfer from the excited state to an auxiliary spin state by a phase locking control pulse. We numerically demonstrate that the storage time is lengthened by spin dephasing time.

  1. Time-delayed feedback control of diffusion in random walkers

    Science.gov (United States)

    Ando, Hiroyasu; Takehara, Kohta; Kobayashi, Miki U.

    2017-07-01

    Time delay in general leads to instability in some systems, while specific feedback with delay can control fluctuated motion in nonlinear deterministic systems to a stable state. In this paper, we consider a stochastic process, i.e., a random walk, and observe its diffusion phenomenon with time-delayed feedback. As a result, the diffusion coefficient decreases with increasing delay time. We analytically illustrate this suppression of diffusion by using stochastic delay differential equations and justify the feasibility of this suppression by applying time-delayed feedback to a molecular dynamics model.

  2. Advanced discrete-time control designs and applications

    CERN Document Server

    Abidi, Khalid

    2015-01-01

    This book covers a wide spectrum of systems such as linear and nonlinear multivariable systems as well as control problems such as disturbance, uncertainty and time-delays. The purpose of this book is to provide researchers and practitioners a manual for the design and application of advanced discrete-time controllers.  The book presents six different control approaches depending on the type of system and control problem. The first and second approaches are based on Sliding Mode control (SMC) theory and are intended for linear systems with exogenous disturbances. The third and fourth approaches are based on adaptive control theory and are aimed at linear/nonlinear systems with periodically varying parametric uncertainty or systems with input delay. The fifth approach is based on Iterative learning control (ILC) theory and is aimed at uncertain linear/nonlinear systems with repeatable tasks and the final approach is based on fuzzy logic control (FLC) and is intended for highly uncertain systems with heuristi...

  3. Interruptions and multitasking in surgery: a multicentre observational study of the daily work patterns of doctors and nurses.

    Science.gov (United States)

    Bellandi, Tommaso; Cerri, Alessandro; Carreras, Giulia; Walter, Scott; Mengozzi, Cipriana; Albolino, Sara; Mastrominico, Eleonora; Renzetti, Fernando; Tartaglia, Riccardo; Westbrook, Johanna

    2018-01-01

    The aim of this study was to obtain baseline data on doctors' and nurses' work activities and rates of interruptions and multitasking to improve work organisation and processes. Data were collected in six surgical units with the WOMBAT (Work Observation Method by Activity Timing) tool. Results show that doctors and nurses received approximately 13 interruptions per hour, or one interruption every 4.5 min. Compared to doctors, nurses were more prone to interruptions in most activities, while doctors performed multitasking (33.47% of their time, 95% CI 31.84-35.17%) more than nurses (15.23%, 95% CI 14.24-16.25%). Overall, the time dedicated to patient care is relatively limited for both professions (37.21%, 95% CI 34.95-39.60% for doctors, 27.22%, 95% CI 25.18-29.60% for nurses) compared to the time spent for registration of data and professional communication, that accounts for two-thirds of doctors' time and nearly half of nurses' time. Further investigation is needed on strategies to manage job demands and professional communications. Practitioner Summary: This study offers further findings on the characteristics and frequency of multitasking and interruptions in surgery, with a comparison of how they affect doctors and nurses. Further investigation is needed to improve the management of job demands and communications according to the results.

  4. Simultaneous Provision of Flexible Ramping Product and Demand Relief by Interruptible Loads Considering Economic Incentives

    Directory of Open Access Journals (Sweden)

    Jiahua Hu

    2017-12-01

    Full Text Available To cope with the net load variability in real time, sufficient ramp capability from controllable resources is required. To address the issue of insufficient ramp capacity in real time operations, flexible ramping products (FRPs have been adopted by some Independent System Operators (ISOs in the USA as a new market design. The inherent variability and uncertainty caused by renewable energy sources (RESs call for new FRP providers apart from conventional generating units. The so-called interruptible load (IL has proved to be useful in maintaining the supply-demand balance by providing demand relief and can be a viable FRP provider in practice. Given this background, this work presents a stochastic real-time unit commitment model considering ramp requirement and simultaneous provision of IL for FRP and demand relief. Load serving entities (LSEs are included in the proposed model and act as mediators between the ISO and multiple ILs. In particular, incentive compatible contracts are designed to encourage customers to reveal their true outage costs. Case studies indicate both the system and LSEs can benefit by employing the proposed method and ILs can gain the highest profits by signing up a favorable contract.

  5. A discrete-time adaptive control scheme for robot manipulators

    Science.gov (United States)

    Tarokh, M.

    1990-01-01

    A discrete-time model reference adaptive control scheme is developed for trajectory tracking of robot manipulators. The scheme utilizes feedback, feedforward, and auxiliary signals, obtained from joint angle measurement through simple expressions. Hyperstability theory is utilized to derive the adaptation laws for the controller gain matrices. It is shown that trajectory tracking is achieved despite gross robot parameter variation and uncertainties. The method offers considerable design flexibility and enables the designer to improve the performance of the control system by adjusting free design parameters. The discrete-time adaptation algorithm is extremely simple and is therefore suitable for real-time implementation. Simulations and experimental results are given to demonstrate the performance of the scheme.

  6. Evaluation of Real-time operating systems for FGC controls

    CERN Document Server

    Chalas, Konstantinos

    2015-01-01

    Power Converter Control for various experiments at CERN, is con- ducted using a machine called Function Generator Controller. The cur- rent generation of FGCs being deployed is FGC3. A certain number of FGCs require very fast and precise control, and for these systems, there is uncertainty of whether the existing hardware will be able to provide the level of determinism required. I have worked in the CCS section as a summer student on a project to study the potential of ARM-based CPUs to provide a real time behaviour fit for a future high-performance FGC4. In this paper, i will present the results of my research into real-time vari- ants of Linux and other real-time operating systems on two different ARM CPUs.

  7. Inherent limitations of fixed time servo-controlled radiometric calorimetry

    International Nuclear Information System (INIS)

    Wetzel, J.R.; Duff, M.F.; Lemming, J.F.

    1987-01-01

    There has been some interest in low precision, short run time calorimetry measurements. This type of calorimetry measurement has been proposed for use when high precision measurements are not required, for example, to screen scrap containers to determine if there is enough material to be measured more accurately of for confirmatory measurements that only require low precision results. The equipment needed to make these measurements is a servo-controlled calorimeter with a sample preequilibration bath. The preequilibration bath temperature is set to the internal temperature of the calorimeter running at a fixed servo-controlled wattage level. The sample power value is determined at a fixed time form the sample loading into the calorimeter. There are some limitations and areas of uncertainties in the use of data obtained by this method. Data collected under controlled conditions demonstrate the limitations. Sample packaging, preequilibration time, and item wattage were chosen as the variables most likely to be encountered in a plant environment

  8. Timing and control monitor system upgrade design document. Version 4

    International Nuclear Information System (INIS)

    Brandt, J.J.

    1984-01-01

    This is a design document for the Timing and Control Monitor System Upgrade Project. This project is intended to provide a replacement system for the existing user Encoder Monitor Systems and Varian 72 Control Room computer systems. All of these systems reside at the Nevada Test Site. The function of the T and C Monitor System is to gather real-time statistics and data on user defined key variables from control, communication, data acquistion systems, and from the monitoring system itself. The control, communication, and data acquisition systems each operate separately from the monitor system. The T and C Monitor System gathers this data in order to verify the readiness of an event to begin countdown. This includes setup, verification, calibration, and peripheral services, report any failures that may occur during the countdown, verify detonation and containment, and assist reentry activities after the event

  9. Computation of reactor control rod drop time under accident conditions

    International Nuclear Information System (INIS)

    Dou Yikang; Yao Weida; Yang Renan; Jiang Nanyan

    1998-01-01

    The computational method of reactor control rod drop time under accident conditions lies mainly in establishing forced vibration equations for the components under action of outside forces on control rod driven line and motion equation for the control rod moving in vertical direction. The above two kinds of equations are connected by considering the impact effects between control rod and its outside components. Finite difference method is adopted to make discretization of the vibration equations and Wilson-θ method is applied to deal with the time history problem. The non-linearity caused by impact is iteratively treated with modified Newton method. Some experimental results are used to validate the validity and reliability of the computational method. Theoretical and experimental testing problems show that the computer program based on the computational method is applicable and reliable. The program can act as an effective tool of design by analysis and safety analysis for the relevant components

  10. The response-time distribution in a real-time database with optimistic concurrency control and constant execution times

    NARCIS (Netherlands)

    Sassen, S.A.E.; Wal, van der J.

    1997-01-01

    For a real-time shared-memory database with optimistic concurrency control, an approximation for the transaction response-time distribution is obtained. The model assumes that transactions arrive at the database according to a Poisson process, that every transaction uses an equal number of

  11. The response-time distribution in a real-time database with optimistic concurrency control and exponential execution times

    NARCIS (Netherlands)

    Sassen, S.A.E.; Wal, van der J.

    1997-01-01

    For a real-time shared-memory database with optimistic concurrency control, an approximation for the transaction response-time distribution is obtained. The model assumes that transactions arrive at the database according to a Poisson process, that every transaction takes an exponential execution

  12. A theory of Markovian time-inconsistent stochastic control in discrete time

    DEFF Research Database (Denmark)

    Bjork, Tomas; Murgoci, Agatha

    2014-01-01

    We develop a theory for a general class of discrete-time stochastic control problems that, in various ways, are time-inconsistent in the sense that they do not admit a Bellman optimality principle. We attack these problems by viewing them within a game theoretic framework, and we look for subgame...

  13. The response time distribution in a real-time database with optimistic concurrency control

    NARCIS (Netherlands)

    Sassen, S.A.E.; Wal, van der J.

    1996-01-01

    For a real-time shared-memory database with optimistic concurrency control, an approximation for the transaction response time distribution is obtained. The model assumes that transactions arrive at the database according to a Poisson process, that every transaction uses an equal number of

  14. Decentralized control of discrete-time linear time invariant systems with input saturation

    NARCIS (Netherlands)

    Deliu, C.; Deliu, Ciprian; Malek, Babak; Roy, Sandip; Saberi, Ali; Stoorvogel, Antonie Arij

    We study decentralized stabilization of discrete-time linear time invariant (LTI) systems subject to actuator saturation, using LTI controllers. The requirement of stabilization under both saturation constraints and decentralization impose obvious necessary conditions on the open-loop plant, namely

  15. Neurocognition and quality of life after reinitiating antiretroviral therapy in children randomized to planned treatment interruption

    NARCIS (Netherlands)

    Ananworanich, Jintanat; Melvin, Diane; Amador, Jose T. R.; Childs, Tristan; Medin, Gabriela; Boscolo, Valentina; Compagnucci, Alexandra; Kanjanavanit, Suparat; Montero, Samuel; Gibb, Diana M.; Aboulker, J. -P.; Babiker, A.; Belfrage, E.; Bernardi, S.; Bologna, R.; Burger, D.; Butler, K.; Castelli-Gattinara, G.; Castro, H.; Clayden, P.; Compagnucci, A.; Cressey, T.; Darbyshire, J. H.; Debré, M.; de Groot, R.; della Negra, M.; Di Biagio, A.; de Rossi, A.; Duicelescu, D.; Faye, A.; Giaquinto, C.; Giacomet, V.; Gibb, D. M.; Grosch-Wörner, I.; Hainault, M.; Klein, N.; Lallemant, M.; Levy, J.; Lyall, H.; Marczynska, M.; Marques, L.; Mardarescu, M.; Mellado Peña, M. J.; Nadal, D.; Nastouli, E.; Naver, L.; Niehues, T.; Peckham, C.; Pillay, D.; Popieska, J.; Ramos Amador, J. T.; Rojo Conejo, P.; Rosado, L.; Rosso, R.; Rudin, C.; Scherpbier, H. J.; Sharland, M.; Stevanovic, M.; Thorne, C.; Tovo, P. A.; Tudor-Williams, G.; Turkova, A.; Valerius, N.; Volokha, A.; Walker, A. S.; Welch, S.; Wintergerst, U.; Aboulker, J. P.; Burger, D. M.; Green, H.; Harper, L.; Mofenson, L.; Moye, J.; Saïdi, Y.; Cressey, T. R.; Jacqz-Aigrain, E.; Khoo, S.; Regazzi, M.; Tréluyer, J. M.; Ngo-Giang-Huong, N.; Muñoz Fernandez, M. A.; Hill, C.; Lepage, P.; Pozniak, A.; Vella, S.; Chêne, G.; Vesikari, T.; Hadjou, G.; Léonardo, S.; Riault, Y.; Bleier, J.; Buck, L.; Duong, T.; Farrelly, L.; Forcat, S.; Harrison, L.; Horton, J.; Johnson, D.; Montero, S.; Taylor, C.; Chalermpantmetagul, S.; Peongjakta, R.; Khamjakkaew, W.; Than-in-at, K.; Chailert, S.; Jourdain, G.; Le Coeur, S.; Floret, D.; Costanzo, P.; Le Thi, T. T.; Monpoux, F.; Mellul, S.; Caranta, I.; Boudjoudi, N.; Firtion, G.; Denon, M.; Charlemaine, E.; Picard, F.; Hellier, E.; Heuninck, C.; Damond, F.; Alexandre, G.; Tricoire, J.; Antras, M.; Lachendowier, C.; Nicot, F.; Krivine, A.; Rivaux, D.; Notheis, G.; Strotmann, G.; Schlieben, S.; Rampon, O.; Boscolo, V.; Zanchetta, M.; Ginocchio, F.; Viscoli, C.; Martino, A.; Pontrelli, G.; Baldassar, S.; Concato, C.; Mazza, A.; Rossetti, G.; Dobosz, S.; Oldakowska, A.; Popielska, J.; Kaflik, M.; Stanczak, J.; Stanczack, G.; Dyda, T.; Kruk, M.; González Tomé, M. I.; Delgado García, R.; Fernandez Gonzalez, M. T.; Medin, G.; Mellado Peña, M. José; Martín Fontelos, P.; Garcia Mellado, M. I.; Medina, A. F.; Ascencion, B.; Garcia Bermejo, I.; Navarro Gomez, D. M. L.; Saavedra, J.; Prieto, C.; Jimenez, J. L.; Muñoz-Fernandez, M. A.; Garcia Torre, A.; de José Gómez, M. I.; García Rodriguez, M. C.; Moreno Pérez, D.; Núñez Cuadros, E.; Asensi-Botet, F.; Otero Reigada, C.; Pérez Tamarit, M. D.; Vilalta, R.; Molina Moreno, J. M.; Rainer, Truninger; Schupbach, J.; Rutishauser, M.; Bunupuradah, T.; Butterworth, O.; Phasomsap, C.; Prasitsuebsai, W.; Chuanjaroen, T.; Jupimai, T.; Ubolyam, S.; Phanuphak, P.; Puthanakit, T.; Pancharoen, C.; Mai, Chaing; Kanjanavanit, S.; Namwong, T.; Punsakoon, W.; Payakachat, S.; Chutima, D.; Raksasang, M.; Foster, C.; Hamadache, D.; Campbell, S.; Newbould, C.; Monrose, C.; Abdulla, A.; Walley, A.; Melvin, D.; Patel, D.; Kaye, S.; Seery, P.; Rankin, A.; Wildfire, A.; Novelli, V.; Shingadia, D.; Moshal, K.; Flynn, J.; Clapson, M.; Allen, A.; Spencer, L.; Rackstraw, C.; Ward, B.; Parkes, K.; Depala, M.; Jacobsen, M.; Poulsom, H.; Barkley, L.; Miah, J.; Lurie, P.; Keane, C.; McMaster, P.; Phipps, M.; Orendi, J.; Farmer, C.; Liebeschuetz, S.; Sodeinde, O.; Wong, S.; Bostock, V.; Heath, Y.; Scott, S.; Gandhi, K.; Lewis, P.; Daglish, J.; Miles, K.; Summerhill, L.; Subramaniam, B.; Weiner, L.; Famiglietti, M.; Rana, S.; Yu, P.; Roa, J.; Puga, A.; Haerry, A.

    2016-01-01

    Objective: Understanding the effects of antiretroviral treatment (ART) interruption on neurocognition and quality of life (QoL) are important for managing unplanned interruptions and planned interruptions in HIV cure research. Design: Children previously randomized to continuous (continuous ART, n =

  16. Soft Real-Time PID Control on a VME Computer

    Science.gov (United States)

    Karayan, Vahag; Sander, Stanley; Cageao, Richard

    2007-01-01

    microPID (uPID) is a computer program for real-time proportional + integral + derivative (PID) control of a translation stage in a Fourier-transform ultraviolet spectrometer. microPID implements a PID control loop over a position profile at sampling rate of 8 kHz (sampling period 125microseconds). The software runs in a strippeddown Linux operating system on a VersaModule Eurocard (VME) computer operating in real-time priority queue using an embedded controller, a 16-bit digital-to-analog converter (D/A) board, and a laser-positioning board (LPB). microPID consists of three main parts: (1) VME device-driver routines, (2) software that administers a custom protocol for serial communication with a control computer, and (3) a loop section that obtains the current position from an LPB-driver routine, calculates the ideal position from the profile, and calculates a new voltage command by use of an embedded PID routine all within each sampling period. The voltage command is sent to the D/A board to control the stage. microPID uses special kernel headers to obtain microsecond timing resolution. Inasmuch as microPID implements a single-threaded process and all other processes are disabled, the Linux operating system acts as a soft real-time system.

  17. Discrete-time control system design with applications

    CERN Document Server

    Rabbath, C A

    2014-01-01

    This book presents practical techniques of discrete-time control system design. In general, the design techniques lead to low-order dynamic compensators that ensure satisfactory closed-loop performance for a wide range of sampling rates. The theory is given in the form of theorems, lemmas, and propositions. The design of the control systems is presented as step-by-step procedures and algorithms. The proposed feedback control schemes are applied to well-known dynamic system models. This book also discusses: Closed-loop performance of generic models of mobile robot and airborne pursuer dynamic systems under discrete-time feedback control with limited computing capabilities Concepts of discrete-time models and sampled-data models of continuous-time systems, for both single- and dual-rate operation Local versus global digital redesign Optimal, closed-loop digital redesign methods Plant input mapping design Generalized holds and samplers for use in feedback control loops, Numerical simulation of fixed-point arithm...

  18. Guaranteed Cost Finite-Time Control of Discrete-Time Positive Impulsive Switched Systems

    Directory of Open Access Journals (Sweden)

    Leipo Liu

    2018-01-01

    Full Text Available This paper considers the guaranteed cost finite-time boundedness of discrete-time positive impulsive switched systems. Firstly, the definition of guaranteed cost finite-time boundedness is introduced. By using the multiple linear copositive Lyapunov function (MLCLF and average dwell time (ADT approach, a state feedback controller is designed and sufficient conditions are obtained to guarantee that the corresponding closed-loop system is guaranteed cost finite-time boundedness (GCFTB. Such conditions can be solved by linear programming. Finally, a numerical example is provided to show the effectiveness of the proposed method.

  19. RFX: New tools for real-time MHD control

    International Nuclear Information System (INIS)

    Gnesotto, F.; Luchetta, A.; Marchiori, G.

    2005-01-01

    RFX has been recently modified to improve its capability of controlling different MHD phenomena by means of fast, feedback controlled amplifiers and distributed radial field inductors. The paper, after summarizing the principal results obtained in the past by means of active control of magnetic fields in RFX, describes the recent modifications to the machine and the improvements to the power supplies and to the magnetic diagnostics. The old thick shell has been replaced by a much thinner shell, whose electromagnetic time constants are much shorter than pulse duration, and a system of 192 radial field coils has been added, covering the whole torus surface. Then the paper describes the models used to design the new real-time control system of RFX and gives some preliminary results obtained, with the same techniques, on the EXTRAP-T2R device. The basic choices about the technologies adopted for the new RFX control system are discussed with reference to the general problem of real-time control of MHD instabilities in magnetic fusion devices. Finally, the paper defines the main objectives of the RFX scientific programme aimed at exploiting these new tools. (author)

  20. Brain activity patterns induced by interrupting the cognitive processes with online advertising.

    Science.gov (United States)

    Rejer, Izabela; Jankowski, Jarosław

    2017-11-01

    As a result of the increasing role of online advertising and strong competition among advertisers, intrusive techniques are commonly used to attract web users' attention. Moreover, since marketing content is usually delivered to the target audience when they are performing typical online tasks, like searching for information or reading online content, its delivery interrupts the web user's current cognitive process. The question posed by many researchers in the field of online advertising is: how should we measure the influence of interruption of cognitive processes on human behavior and emotional state? Much research has been conducted in this field; however, most of this research has focused on monitoring activity in the simulated environment, or processing declarative responses given by users in prepared questionnaires. In this paper, a more direct real-time approach is taken, and the effect of the interruption on a web user is analyzed directly by studying the activity of his brain. This paper presents the results of an experiment that was conducted to find the brain activity patterns associated with interruptions of the cognitive process by showing internet advertisements during a text-reading task. Three specific aspects were addressed in the experiment: individual patterns, the consistency of these patterns across trials, and the intra-subject correlation of the individual patterns. Two main effects were observed for most subjects: a drop in activity in the frontal and prefrontal cortical areas across all frequency bands, and significant changes in the frontal/prefrontal asymmetry index.

  1. The costs of power interruptions in Germany. An assessment in the light of the Energiewende

    Energy Technology Data Exchange (ETDEWEB)

    Growitsch, Christian; Malischek, Raimund; Nick, Sebastian; Wetzel, Heike

    2013-04-15

    The German Energiewende's potential effects on the reliability of electricity supply as well as the corresponding economic consequences have recently entered both the political and scientific debate. However, empirical evidence of power outage costs in Germany is rather scarce. Following a macroeconomic approach, we analyse the economic costs imposed by potential power interruptions in Germany. Investigating a rich data set on industry and households we estimate both Values of Lost Load (VoLLs) and associated costs of power interruptions for different German regions and sectors and every hour of the year. This disaggregated approach allows for conclusions for optimal load shedding in case of technical necessity and the economic efficiency of measures to improve security of supply. We find that interruption costs vary significantly over time, between sectors and regions. Peaking on midday of a Monday in December at 750 Mio Euro per hour, the average of total national outage costs amount to approximately 430 Mio Euro per hour. The industrial sectors facing the highest outage costs are the machinery and transport equipment sectors. Their aggregated hourly outage costs average out at approximately 20 Mio Euro. Our results emphasize the prominent regional aspect of the German Energiewende as the regions with the highest estimated cost of interruptions in South and West Germany coincide with the areas which face nuclear power plant shut downs in the near future.

  2. Time dependent optimal switching controls in online selling models

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Cohen, Albert [MICHIGAN STATE UNIV

    2010-01-01

    We present a method to incorporate dishonesty in online selling via a stochastic optimal control problem. In our framework, the seller wishes to maximize her average wealth level W at a fixed time T of her choosing. The corresponding Hamilton-Jacobi-Bellmann (HJB) equation is analyzed for a basic case. For more general models, the admissible control set is restricted to a jump process that switches between extreme values. We propose a new approach, where the optimal control problem is reduced to a multivariable optimization problem.

  3. Soft Time-Suboptimal Controlling Structure for Mechanical Systems

    DEFF Research Database (Denmark)

    Kulczycki, Piotr; Wisniewski, Rafal; Kowalski, Piotr

    2004-01-01

    The paper presents conception of a soft control structure based on the time-optimal approach. Its parameters are selected in accordance with the rules of the statistical decision theory and additionally it allows to eliminate rapid changes in control values. The object is a basic mechanical system......, with uncertain (also non-stationary) mass treated as a stochastic process. The methodology proposed here is of a universal nature and may easily be applied with respect to other uncertainty elements of timeoptimal controlled mechanical systems....

  4. Academic Training: Real Time Process Control - Lecture series

    CERN Multimedia

    Françoise Benz

    2004-01-01

    ACADEMIC TRAINING LECTURE REGULAR PROGRAMME 7, 8 and 9 June From 11:00 hrs to 12:00 hrs - Main Auditorium bldg. 500 Real Time Process Control T. Riesco / CERN-TS What exactly is meant by Real-time? There are several definitions of real-time, most of them contradictory. Unfortunately the topic is controversial, and there does not seem to be 100% agreement over the terminology. Real-time applications are becoming increasingly important in our daily lives and can be found in diverse environments such as the automatic braking system on an automobile, a lottery ticket system, or robotic environmental samplers on a space station. These lectures will introduce concepts and theory like basic concepts timing constraints, task scheduling, periodic server mechanisms, hard and soft real-time.ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch

  5. Real-time fault diagnosis and fault-tolerant control

    OpenAIRE

    Gao, Zhiwei; Ding, Steven X.; Cecati, Carlo

    2015-01-01

    This "Special Section on Real-Time Fault Diagnosis and Fault-Tolerant Control" of the IEEE Transactions on Industrial Electronics is motivated to provide a forum for academic and industrial communities to report recent theoretic/application results in real-time monitoring, diagnosis, and fault-tolerant design, and exchange the ideas about the emerging research direction in this field. Twenty-three papers were eventually selected through a strict peer-reviewed procedure, which represent the mo...

  6. Tool set for distributed real-time machine control

    Science.gov (United States)

    Carrott, Andrew J.; Wright, Christopher D.; West, Andrew A.; Harrison, Robert; Weston, Richard H.

    1997-01-01

    Demands for increased control capabilities require next generation manufacturing machines to comprise intelligent building elements, physically located at the point where the control functionality is required. Networks of modular intelligent controllers are increasingly designed into manufacturing machines and usable standards are slowly emerging. To implement a control system using off-the-shelf intelligent devices from multi-vendor sources requires a number of well defined activities, including (a) the specification and selection of interoperable control system components, (b) device independent application programming and (c) device configuration, management, monitoring and control. This paper briefly discusses the support for the above machine lifecycle activities through the development of an integrated computing environment populated with an extendable software toolset. The toolset supports machine builder activities such as initial control logic specification, logic analysis, machine modeling, mechanical verification, application programming, automatic code generation, simulation/test, version control, distributed run-time support and documentation. The environment itself consists of system management tools and a distributed object-oriented database which provides storage for the outputs from machine lifecycle activities and specific target control solutions.

  7. Multiple Estimation Architecture in Discrete-Time Adaptive Mixing Control

    Directory of Open Access Journals (Sweden)

    Simone Baldi

    2013-05-01

    Full Text Available Adaptive mixing control (AMC is a recently developed control scheme for uncertain plants, where the control action coming from a bank of precomputed controller is mixed based on the parameter estimates generated by an on-line parameter estimator. Even if the stability of the control scheme, also in the presence of modeling errors and disturbances, has been shown analytically, its transient performance might be sensitive to the initial conditions of the parameter estimator. In particular, for some initial conditions, transient oscillations may not be acceptable in practical applications. In order to account for such a possible phenomenon and to improve the learning capability of the adaptive scheme, in this paper a new mixing architecture is developed, involving the use of parallel parameter estimators, or multi-estimators, each one working on a small subset of the uncertainty set. A supervisory logic, using performance signals based on the past and present estimation error, selects the parameter estimate to determine the mixing of the controllers. The stability and robustness properties of the resulting approach, referred to as multi-estimator adaptive mixing control (Multi-AMC, are analytically established. Besides, extensive simulations demonstrate that the scheme improves the transient performance of the original AMC with a single estimator. The control scheme and the analysis are carried out in a discrete-time framework, for easier implementation of the method in digital control.

  8. Resilience of Urban Smart Grids Involving Multiple Control Loops

    DEFF Research Database (Denmark)

    Madsen, Jacob Theilgaard; Pillai, Jayakrishnan Radhakrishna; Schwefel, Hans-Peter

    2016-01-01

    Intelligent control of energy distribution grids is implemented via a hierarchy of control loops with different input values and different control targets, which also work on different time-scales. This control is enabled by a bi-directional communication flow, which can be interrupted due to ICT...

  9. Preserving the Context of Interrupted Business Process Activities

    NARCIS (Netherlands)

    Bassil, S.; Rinderle, S.B.; Keller, R.; Reichert, M.U.; Kropf, P.G.

    2005-01-01

    The capability to safely interrupt business process activities is an important requirement for advanced process-aware information systems. Indeed, exceptions stemming from the application environment often appear while one or more application-related process activities are running. Safely

  10. Preserving the Context of Interrupted Business Process Activities

    NARCIS (Netherlands)

    Bassil, S.; Rinderle, S.B.; Keller, R.; Kropf, P.G.; Reichert, M.U.; Chen, C.S.; Filipe, J.; Seruca, I.; Cordeiro, J.

    2006-01-01

    The capability to safely interrupt business process activities is an important requirement for advanced process-aware information systems. Indeed, exceptions stemming from the application environment often appear while one or more application-related process activities are running. Safely

  11. HIV models for treatment interruption: Adaptation and comparison

    Science.gov (United States)

    Hillmann, Andreas; Crane, Martin; Ruskin, Heather J.

    2017-10-01

    In recent years, Antiretroviral Therapy (ART) has become commonplace for treating HIV infections, although a cure remains elusive, given reservoirs of replicating latently-infected cells, which are resistant to normal treatment regimes. Treatment interruptions, whether ad hoc or structured, are known to cause a rapid increase in viral production to detectable levels, but numerous clinical trials remain inconclusive on the dangers inherent in this resurgence. In consequence, interest in examining interruption strategies has recently been rekindled. This overview considers modelling approaches, which have been used to explore the issue of treatment interruption. We highlight their purpose and the formalisms employed and examine ways in which clinical data have been used. Implementation of selected models is demonstrated, illustrative examples provided and model performance compared for these cases. Possible extensions to bottom-up modelling techniques for treatment interruptions are briefly discussed.

  12. Instant Messaging Usage and Interruptions in the Workplace

    Directory of Open Access Journals (Sweden)

    Hui‐Jung Chang

    2014-12-01

    Full Text Available The goal of the present study is to explore IM interruption by relating it to media choices and purposes of IM use in the workplace. Two major media choice concepts were: media richness and social influence; while four purposes of IM use were: organization work, knowledge work, socializing, and boundary spanning activities. Data (N = 283 were collected via a combination of convenience and snowball sampling of “computer‐using workers” in Taiwan, based on the Standard Occupational Classification system published by the Taiwan government. Results indicated that media choice works better than purpose of IM use to explain IM interruption. Among them, social influence was the best predictor to IM interruption in the workplace. In addition, instant feedback and personalization provided by IM, and IM usage for the purposes of knowledge work and socializing, also relate to IM interruption in the workplace.

  13. On Stochastic Finite-Time Control of Discrete-Time Fuzzy Systems with Packet Dropout

    Directory of Open Access Journals (Sweden)

    Yingqi Zhang

    2012-01-01

    Full Text Available This paper is concerned with the stochastic finite-time stability and stochastic finite-time boundedness problems for one family of fuzzy discrete-time systems over networks with packet dropout, parametric uncertainties, and time-varying norm-bounded disturbance. Firstly, we present the dynamic model description studied, in which the discrete-time fuzzy T-S systems with packet loss can be described by one class of fuzzy Markovian jump systems. Then, the concepts of stochastic finite-time stability and stochastic finite-time boundedness and problem formulation are given. Based on Lyapunov function approach, sufficient conditions on stochastic finite-time stability and stochastic finite-time boundedness are established for the resulting closed-loop fuzzy discrete-time system with Markovian jumps, and state-feedback controllers are designed to ensure stochastic finite-time stability and stochastic finite-time boundedness of the class of fuzzy systems. The stochastic finite-time stability and stochastic finite-time boundedness criteria can be tackled in the form of linear matrix inequalities with a fixed parameter. As an auxiliary result, we also give sufficient conditions on the stochastic stability of the class of fuzzy T-S systems with packet loss. Finally, two illustrative examples are presented to show the validity of the developed methodology.

  14. A time-delayed method for controlling chaotic maps

    International Nuclear Information System (INIS)

    Chen Maoyin; Zhou Donghua; Shang Yun

    2005-01-01

    Combining the repetitive learning strategy and the optimality principle, this Letter proposes a time-delayed method to control chaotic maps. This method can effectively stabilize unstable periodic orbits within chaotic attractors in the sense of least mean square. Numerical simulations of some chaotic maps verify the effectiveness of this method

  15. REAL-TIME CONTROL OF COMBINED SEWER NETWORKS

    Science.gov (United States)

    Real-time control (RTC) is a custom-designed management program for a specific urban sewerage system during a wet-weather event. The function of RTC is to assure efficient operation of the sewerage system and maximum utilization of existing storage capacity, either to fully conta...

  16. Design of a real-time hybrid controller

    NARCIS (Netherlands)

    Lim, K.W.; Preisig, H.A.; Rauch, H.E.

    1998-01-01

    This paper describes the framework of an automated supervisory control system realisation. It is developed to support rapid prototyping of real time hybrid con trol systems, described using a simple and flexible set of text descriptors. The design is versatile in allow ing the user to define

  17. Response Times of Operators in a Control Room

    DEFF Research Database (Denmark)

    Platz, O.; Rasmussen, Jens; Skanborg, Preben Zacho

    A statistical analysis was made of operator response times recorded in the control room of a research reactor during the years 1972-1974. A homogeneity test revealed that the data consist of a mixture of populations. A small but statistically significant difference is found between day and night...

  18. Quadratic theory and feedback controllers for linear time delay systems

    International Nuclear Information System (INIS)

    Lee, E.B.

    1976-01-01

    Recent research on the design of controllers for systems having time delays is discussed. Results for the ''open loop'' and ''closed loop'' designs will be presented. In both cases results for minimizing a quadratic cost functional are given. The usefulness of these results is not known, but similar results for the non-delay case are being routinely applied. (author)

  19. BENEFITS OF SEWERAGE SYSTEM REAL-TIME CONTROL

    Science.gov (United States)

    Real-time control (RTC) is a custom-designed computer-assisted management system for a specific urban sewerage network that is activated during a wet-weather flow event. Though uses of RTC systems had started in the mid 60s, recent developments in computers, telecommunication, in...

  20. Approximator: Predicting Interruptibility in Software Development with Commodity Computers

    DEFF Research Database (Denmark)

    Tell, Paolo; Jalaliniya, Shahram; Andersen, Kristian S. M.

    2015-01-01

    Assessing the presence and availability of a remote colleague is key in coordination in global software development but is not easily done using existing computer-mediated channels. Previous research has shown that automated estimation of interruptibility is feasible and can achieve a precision....... These early but promising results represent a starting point for designing tools with support for interruptibility capable of improving distributed awareness and cooperation to be used in global software development....

  1. Real Time Optimal Control of Supercapacitor Operation for Frequency Response

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yusheng; Panwar, Mayank; Mohanpurkar, Manish; Hovsapian, Rob

    2016-07-01

    Supercapacitors are gaining wider applications in power systems due to fast dynamic response. Utilizing supercapacitors by means of power electronics interfaces for power compensation is a proven effective technique. For applications such as requency restoration if the cost of supercapacitors maintenance as well as the energy loss on the power electronics interfaces are addressed. It is infeasible to use traditional optimization control methods to mitigate the impacts of frequent cycling. This paper proposes a Front End Controller (FEC) using Generalized Predictive Control featuring real time receding optimization. The optimization constraints are based on cost and thermal management to enhance to the utilization efficiency of supercapacitors. A rigorous mathematical derivation is conducted and test results acquired from Digital Real Time Simulator are provided to demonstrate effectiveness.

  2. Meditation-induced states predict attentional control over time.

    Science.gov (United States)

    Colzato, Lorenza S; Sellaro, Roberta; Samara, Iliana; Baas, Matthijs; Hommel, Bernhard

    2015-12-01

    Meditation is becoming an increasingly popular topic for scientific research and various effects of extensive meditation practice (ranging from weeks to several years) on cognitive processes have been demonstrated. Here we show that extensive practice may not be necessary to achieve those effects. Healthy adult non-meditators underwent a brief single session of either focused attention meditation (FAM), which is assumed to increase top-down control, or open monitoring meditation (OMM), which is assumed to weaken top-down control, before performing an Attentional Blink (AB) task - which assesses the efficiency of allocating attention over time. The size of the AB was considerably smaller after OMM than after FAM, which suggests that engaging in meditation immediately creates a cognitive-control state that has a specific impact on how people allocate their attention over time. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Perceived Time, Temporal Order and Control in Boundaryless Work

    DEFF Research Database (Denmark)

    Lund, Henrik Lambrecht; Hvid, Helge Søndergaard; Kamp, Annette

    2010-01-01

    , habits, breaks, norms and meetings that occur through the inter-personal relationships. Therefore work life research can make use of time sociology concepts to understand and study how control is gained and lost in contemporary work. The results of our study show that individualized time conflicts leave......Contemporary working conditions are very different from just 30 years back. Many changes are characterized as new opportunities for personal development and autonomy for the individual employee. However work life researchers report of increased psychosocial strain and dissemination of work related...... psychological illnesses. This paradoxical tendency questions our basic knowledge about well being at work. For decades employee control has been seen as universal solution to work related psychosocial hazards, but this is now questioned. We find that control is still as important but needs to be studied in new...

  4. Fuzzy controller for real time supervision of nuclear power reactor

    International Nuclear Information System (INIS)

    Bala Subramanian, R.

    2012-01-01

    Generally nuclear energy provides about 60% of the whole electricity production. A modulation of the nuclear power plants must be able to respond to the demand on the network. The pressurized water nuclear reactor has to yield correctly a load set point. Fundamentally, two parameters are concerned in leading this task to a successful conclusion: the power axial-offset and the control rods position. The focus of this study is the automation of the control of the power axial-offset by adding soluble boron and by minimizing the volume flows through the water pump. It is also important to take into consideration the liquid waste volume. Water or boron is injected into the reactor primary circuit. At the present time this task is still performed manually by an operator, for all previous attempts to automate it failed. That device, sketchily described in the paper, gave rise to the development of a real-time fuzzy controller for the power axial-offset and the control rods insertion in a pressurized water reactor (PWR). The fuzzy controller, which is the main subject of the paper, expresses more naturally the human expertise, thus avoiding the previous issue of empirical tunings. It was implemented in simulation using Matlab-Simulink on a Sun workstation. Two realistic tests discussed show that the fuzzy controller runs as efficiently as an expert operator does

  5. On Tuning PI Controllers for Integrating Plus Time Delay Systems

    Directory of Open Access Journals (Sweden)

    David Di Ruscio

    2010-10-01

    Full Text Available Some analytical results concerning PI controller tuning based on integrator plus time delay models are worked out and presented. A method for obtaining PI controller parameters, Kp=alpha/(k*tau, and, Ti=beta*tau, which ensures a given prescribed maximum time delay error, dtau_max, to time delay, tau, ratio parameter delta=dau_max/tau, is presented. The corner stone in this method, is a method product parameter, c=alpha*beta. Analytical relations between the PI controller parameters, Ti, and, Kp, and the time delay error parameter, delta, is presented, and we propose the setting, beta=c/a*(delta+1, and, alpha=a/(delta+1, which gives, Ti=c/a*(delta+1*tau, and Kp=a/((delta+1*k*tau, where the parameter, a, is constant in the method product parameter, c=alpha*beta. It also turns out that the integral time, Ti, is linear in, delta, and the proportional gain, Kp, inversely proportional to, delta+1. For the original Ziegler Nichols (ZN method this parameter is approximately, c=2.38, and the presented method may e.g., be used to obtain new modified ZN parameters with increased robustness margins, also documented in the paper.

  6. Radiation therapy for T1,2 glottic carcinoma: impact of overall treatment time on local control

    International Nuclear Information System (INIS)

    Nishimura, Yasumasa; Nagata, Yasushi; Okajima, Kaoru; Mitsumori, Michihide; Hiraoka, Masahiro; Masunaga, Shin-ichirou; Ono, Koji; Shoji, Kazuhiko; Kojima, Hisayosi

    1996-01-01

    Purpose: Local control probabilities of T1,2 glottic laryngeal cancer were evaluated in relation to dose and fractionation of radiation therapy (RT). Materials and methods: Between 1975 and 1993, 96 T1N0M0 glottic cancers and 32 T2N0M0 glottic cancers were treated with definitive RT. Total RT dose was 60-66 Gy/2 Gy for most of the T1 and T2 tumors, although 10 T2 tumors were treated with hyperfractionation (72-74.4 Gy/1.2 Gy bid). Of the 128 patients, 90 T1 glottic tumors and 30 T2 glottic tumors were followed for >2 years after treatment. Multivariate analyses using the Cox proportional hazards model and a logistic regression analysis were performed to evaluate the significance of prognostic variables on local control. Results: The 5-year local control probability for T1 tumors was 85%, whereas that for T2 tumors was 71%. Multivariate analyses demonstrated that only overall treatment time (OTT) was a significant variable for local control. Total RT dose, normalized total doses at a fraction size of 2 Gy, and fraction size were not significant. Local control probability of T1 tumors with an OTT of 42-49 days was significantly higher than that of tumors with an OTT of >49 days (P < 0.02). Only a 1-week interruption of RT, due to holidays, significantly reduced the 5-year local control probability of T1 glottic tumors from 89 to 74% (P < 0.05). Conclusions: These results indicate that OTT is a significant prognostic factor for local control of T1 glottic tumors

  7. Surveillance of hazardous substances releases due to system interruptions, 2002.

    Science.gov (United States)

    Orr, Maureen F; Ruckart, Perri Zeitz

    2007-04-11

    The Hazardous Substances Emergency Events Surveillance (HSEES) system collected information on 9014 acute hazardous substance releases in 15 participating states in 2002. There were 3749 fixed-facility manufacturing events, of which 2100 involved "interruptions" to normal processing and 1649 "comparisons" that did not involve interruption. Equipment failure (69%) or intentional acts (20%) were the main root factor. Many events occurred in October and November in three states (Texas, Louisiana, and New Jersey), in three manufacturing industries (industrial and miscellaneous chemicals; petroleum refining; and plastics, synthetics, and resins). In interruption events, the substance categories most often released were mixtures, other inorganic substances, and volatile organic compounds and those most often causing injury were acids, chlorine, bases, and ammonia. Comparison events resulted in more acutely injured persons (408 versus 59) and more evacuees (11,318 versus 335) than interruption events and therefore may receive more public health attention. Because of the large number of interruption events, targeted prevention activities, including management of change procedures, lessons-learned implementation, process hazards analysis, and appropriate protection for workers could be economically advantageous and improve environmental quality. Efforts should focus on the identified areas of greater occurrence. The relationship of weather and equipment failure with interruption events needs further investigation.

  8. Tests of vacuum interrupters for the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Warren, R.; Parsons, M.; Honig, E.; Lindsay, J.

    1979-04-01

    The Tokamak Fusion Test Reactor (TFTR) project at Princeton University requires the insertion of a resistor in an excited ohmic-heating coil circuit to produce a plasma initiation pulse (PIP). It is expected that the maximum duty for the switching system will be an interruption of 24 kA with an associated recovery voltage of 25 kV. Vacuum interrupters were selected as the most economical means to satisfy these requirements. However, it was felt that some testing of available systems should be performed to determine their reliability under these conditions. Two interrupter systems were tested for over 1000 interruptions each at 24 kA and 25 kV. One system employed special Westinghouse type WL-33552 interrupters in a circuit designed by LASL. This circuit used a commercially available actuator and a minimum size counterpulse bank and saturable reactor. The other used Toshiba type VGB2-D20 interrupters actuated by a Toshiba mechanism in a Toshiba circuit using a larger counterpulse bank and saturable reactor

  9. REAL TIME ANALYSIS OF WIRELESS CONTROLLER AREA NETWORK

    Directory of Open Access Journals (Sweden)

    Gerardine Immaculate Mary

    2014-09-01

    Full Text Available It is widely known that Control Area Networks (CAN are used in real-time, distributed and parallel processing which cover manufacture plants, humanoid robots, networking fields, etc., In applications where wireless conditions are encountered it is convenient to continue the exchange of CAN frames within the Wireless CAN (WCAN. The WCAN considered in this research is based on wireless token ring protocol (WTRP; a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message based communication. WCAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and good packet delivery ratio. The most important factor to consider when evaluating a control network is the end-to-end time delay between sensors, controllers, and actuators. The correct operation of a control system depends on the timeliness of the data coming over the network, and thus, a control network should be able to guarantee message delivery within a bounded transmission time. The proposed WCAN is modeled and simulated using QualNet, and its average end to end delay and packet delivery ratio (PDR are calculated. The parameters boundaries of WCAN are evaluated to guarantee a maximum throughput and a minimum latency time, in the case of wireless communications, precisely WCAN.

  10. Finite-Time Synchronizing Control for Chaotic Neural Networks

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2014-01-01

    Full Text Available This paper addresses the finite-time synchronizing problem for a class of chaotic neural networks. In a real communication network, parameters of the master system may be time-varying and the system may be perturbed by external disturbances. A simple high-gain observer is designed to track all the nonlinearities, unknown system functions, and disturbances. Then, a dynamic active compensatory controller is proposed and by using the singular perturbation theory, the control method can guarantee the finite-time stability of the error system between the master system and the slave system. Finally, two illustrative examples are provided to show the effectiveness and applicability of the proposed scheme.

  11. Resonant power converter comprising adaptive dead-time control

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates in a first aspect to a resonant power converter comprising: a first power supply rail for receipt of a positive DC supply voltage and a second power supply rail for receipt of a negative DC supply voltage. The resonant power converter comprises a resonant network with an input...... terminal for receipt of a resonant input voltage from a driver circuit. The driver circuit is configured for alternatingly pulling the resonant input voltage towards the positive and negative DC supply voltages via first and second semiconductor switches, respectively, separated by intervening dead......-time periods in accordance with one or more driver control signals. A dead-time controller is configured to adaptively adjusting the dead-time periods based on the resonant input voltage....

  12. The accuracy evaluation according to dose delivery interruption and restart for volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hyung; Bae, Sun Myung; Kwak, Jung Won; Kang, Tae Young; Bck, Geum Mun [Dept. of Radiation Oncology, Asan Medical Center, Seoul(Korea, Republic of)

    2013-03-15

    The accurate movement of gantry rotation, collimator and correct application of dose rate are very important to approach the successful performance of Volumetric Modulated Arc Therapy (VMAT), because it is tightly interlocked with a complex treatment plan. The interruption and restart of dose delivery, however, are able to occur on treatment by various factors of a treatment machine and treatment plan. If unexpected problems of a treat machine or a patient interrupt the VMAT, the movement of treatment machine for delivering the remaining dose will be restarted at the start point. In this investigation, We would like to know the effect of interruptions and restart regarding dose delivery at VMAT. Treatment plans of 10 patients who had been treated at our center were used to measure and compare the dose distribution of each VMAT after converting to a form of digital image and communications in Medicine (DICOM) with treatment planning system (Eclipse V 10.0, Varian, USA). We selected the 6 MV photon energy of Trilogy (Varian, USA) and used OmniPro I'mRT system (V 1.7b, IBA dosimetry, Germany) to analyze the data that were acquired through this measurement with two types of interruptions four times for each case. The door interlock and the beam-off were used to stop and then to restart the dose delivery of VMAT. The gamma index in OmniPro I'mRT system and T-test in Microsoft Excel 2007 were used to evaluate the result of this investigation. The deviations of average gamma index in cases with door interlock, beam-off and without interruption on VMAT are 0.141, 0.128 and 0.1. The standard deviations of acquired gamma values are 0.099, 0.091, 0.071 and The maximum gamma value in each case is 0.413, 0.379, 0.286, respectively. This analysis has a 95-percent confidence level and the P-value of T-test is under 0.05. Gamma pass rate (3%, 3 mm) is acceptable in all of measurements. As a result, We could make sure that the interruption of this investgation are not

  13. Smartphone addiction, daily interruptions and self-reported productivity

    Directory of Open Access Journals (Sweden)

    Éilish Duke

    2017-12-01

    Full Text Available The advent of the smartphone has dramatically altered how we communicate, navigate, work and entertain ourselves. While the advantages of this new technology are clear, constant use may also bring negative consequences, such as a loss of productivity due to interruptions in work life. A link between smartphone overuse and loss of productivity has often been hypothesized, but empirical evidence on this question is scarce. The present study addressed this question by collecting self-report data from N=262 participants, assessing private and work-related smartphone use, smartphone addiction and self-rated productivity. Our results indicate a moderate relationship between smartphone addiction and a self-reported decrease in productivity due to spending time on the smartphone during work, as well as with the number of work hours lost to smartphone use. Smartphone addiction was also related to a greater amount of leisure time spent on the smartphone and was strongly related to a negative impact of smartphone use on daily non-work related activities. These data support the idea that tendencies towards smartphone addiction and overt checking of the smartphone could result in less productivity both in the workplace and at home. Results are discussed in relation to productivity and technostress.

  14. Smartphone addiction, daily interruptions and self-reported productivity.

    Science.gov (United States)

    Duke, Éilish; Montag, Christian

    2017-12-01

    The advent of the smartphone has dramatically altered how we communicate, navigate, work and entertain ourselves. While the advantages of this new technology are clear, constant use may also bring negative consequences, such as a loss of productivity due to interruptions in work life. A link between smartphone overuse and loss of productivity has often been hypothesized, but empirical evidence on this question is scarce. The present study addressed this question by collecting self-report data from N  = 262 participants, assessing private and work-related smartphone use, smartphone addiction and self-rated productivity. Our results indicate a moderate relationship between smartphone addiction and a self-reported decrease in productivity due to spending time on the smartphone during work, as well as with the number of work hours lost to smartphone use. Smartphone addiction was also related to a greater amount of leisure time spent on the smartphone and was strongly related to a negative impact of smartphone use on daily non-work related activities. These data support the idea that tendencies towards smartphone addiction and overt checking of the smartphone could result in less productivity both in the workplace and at home. Results are discussed in relation to productivity and technostress.

  15. The role of interruptions in polyQ in the pathology of SCA1.

    Directory of Open Access Journals (Sweden)

    Rajesh P Menon

    Full Text Available At least nine dominant neurodegenerative diseases are caused by expansion of CAG repeats in coding regions of specific genes that result in abnormal elongation of polyglutamine (polyQ tracts in the corresponding gene products. When above a threshold that is specific for each disease the expanded polyQ repeats promote protein aggregation, misfolding and neuronal cell death. The length of the polyQ tract inversely correlates with the age at disease onset. It has been observed that interruption of the CAG tract by silent (CAA or missense (CAT mutations may strongly modulate the effect of the expansion and delay the onset age. We have carried out an extensive study in which we have complemented DNA sequence determination with cellular and biophysical models. By sequencing cloned normal and expanded SCA1 alleles taken from our cohort of ataxia patients we have determined sequence variations not detected by allele sizing and observed for the first time that repeat instability can occur even in the presence of CAG interruptions. We show that histidine interrupted pathogenic alleles occur with relatively high frequency (11% and that the age at onset inversely correlates linearly with the longer uninterrupted CAG stretch. This could be reproduced in a cellular model to support the hypothesis of a linear behaviour of polyQ. We clarified by in vitro studies the mechanism by which polyQ interruption slows down aggregation. Our study contributes to the understanding of the role of polyQ interruption in the SCA1 phenotype with regards to age at disease onset, prognosis and transmission.

  16. Timing, Trigger and Control Systems for LHC Detectors

    CERN Multimedia

    2002-01-01

    \\\\ \\\\At the LHC, precise bunch-crossing clock and machine orbit signals must be broadcast over distances of several km from the Prevessin Control Room to the four experiment areas and other destinations. At the LHC experiments themselves, quite extensive distribution systems are also required for the transmission of timing, trigger and control (TTC) signals to large numbers of front-end electronics controllers from a single location in the vicinity of the central trigger processor. The systems must control the detector synchronization and deliver the necessary fast signals and messages that are phased with the LHC clock, orbit or bunch structure. These include the bunch-crossing clock, level-1 trigger decisions, bunch and event numbers, as well as test signals and broadcast commands. A common solution to this TTC system requirement is expected to result in important economies of scale and permit a rationalization of the development, operational and support efforts required. LHC Common Project RD12 is developi...

  17. Prototype Real-time ATCA-based LLRF Control System

    CERN Document Server

    Makowski, Dariusz; Jezynski, Tomasz; Piotrowski, Adam; Jablonski, Grzegorz; Jalmuzna, Wojciech; Czuba, Krzysztof; Predki, Paweł; Simrock, Stefan

    2011-01-01

    The linear accelerators employed to drive Free Electron Lasers (FELs), such as the X-ray Free Electron Laser (XFEL) currently being built in Hamburg, require sophisticated control systems. The Low Level Radio Frequency (LLRF) control system should stabilize the phase and amplitude of the electromagnetic field in accelerating modules with tolerances below 0.02 % for amplitude and 0.01 degree for phase to produce ultra-stable electron beam that meets the conditions required for Self-Amplified Spontaneous Emission (SASE). The LLRF control system of 32-cavity accelerating module of the XFEL accelerator requires acquisition of more than 100 analogue signals sampled with frequency around 100 MHz. Data processing in real-time loop should complete within a few hundreds of nanoseconds. Moreover, the LLRF control system should be reliable, upgradable and serviceable. The Advanced Telecommunications Computing Architecture (ATCA) standard, developed for telecommunication applications, can fulfil all of the above mentione...

  18. Stochastic ℋ∞ Finite-Time Control of Discrete-Time Systems with Packet Loss

    Directory of Open Access Journals (Sweden)

    Yingqi Zhang

    2012-01-01

    Full Text Available This paper investigates the stochastic finite-time stabilization and ℋ∞ control problem for one family of linear discrete-time systems over networks with packet loss, parametric uncertainties, and time-varying norm-bounded disturbance. Firstly, the dynamic model description studied is given, which, if the packet dropout is assumed to be a discrete-time homogenous Markov process, the class of discrete-time linear systems with packet loss can be regarded as Markovian jump systems. Based on Lyapunov function approach, sufficient conditions are established for the resulting closed-loop discrete-time system with Markovian jumps to be stochastic ℋ∞ finite-time boundedness and then state feedback controllers are designed to guarantee stochastic ℋ∞ finite-time stabilization of the class of stochastic systems. The stochastic ℋ∞ finite-time boundedness criteria can be tackled in the form of linear matrix inequalities with a fixed parameter. As an auxiliary result, we also give sufficient conditions on the robust stochastic stabilization of the class of linear systems with packet loss. Finally, simulation examples are presented to illustrate the validity of the developed scheme.

  19. Interruption of People in Human-Computer Interaction: A General Unifying Definition of Human Interruption and Taxonomy

    National Research Council Canada - National Science Library

    McFarlane, Daniel

    1997-01-01

    .... This report asserts that a single unifying definition of user-interruption and the accompanying practical taxonomy would be useful theoretical tools for driving effective investigation of this crucial...

  20. Sensitivity of control times in function of core parameters and oscillations control in thermal nuclear systems

    International Nuclear Information System (INIS)

    Amorim, E.S. do; D'Oliveira, A.B.; Galvao, O.B.; Oyama, K.

    1981-03-01

    Sensitivity of control times to variation of a thermal reactor core parameters is defined by suitable changes in the power coefficient, core size and fuel enrichment. A control strategy is developed based on control theory concepts and on considerations of the physics of the problem. Digital diffusion theory simulation is described which tends to verify the control concepts considered, face dumped oscillations introduced in one thermal nuclear power system. The effectivity of the control actions, in terms of eliminating oscillations, provided guidelines for the working-group engaged in the analysis of the control rods and its optimal performance. (Author) [pt

  1. Industrial Raman gas sensing for real-time system control

    Science.gov (United States)

    Buric, M.; Mullen, J.; Chorpening, B.; Woodruff, S.

    2014-06-01

    Opportunities exist to improve on-line process control in energy applications with a fast, non-destructive measurement of gas composition. Here, we demonstrate a Raman sensing system which is capable of reporting the concentrations of numerous species simultaneously with sub-percent accuracy and sampling times below one-second for process control applications in energy or chemical production. The sensor is based upon a hollow-core capillary waveguide with a 300 micron bore with reflective thin-film metal and dielectric linings. The effect of using such a waveguide in a Raman process is to integrate Raman photons along the length of the sample-filled waveguide, thus permitting the acquisition of very large Raman signals for low-density gases in a short time. The resultant integrated Raman signals can then be used for quick and accurate analysis of a gaseous mixture. The sensor is currently being tested for energy applications such as coal gasification, turbine control, well-head monitoring for exploration or production, and non-conventional gas utilization. In conjunction with an ongoing commercialization effort, the researchers have recently completed two prototype instruments suitable for hazardous area operation and testing. Here, we report pre-commercialization testing of those field prototypes for control applications in gasification or similar processes. Results will be discussed with respect to accuracy, calibration requirements, gas sampling techniques, and possible control strategies of industrial significance.

  2. The effect of interrupted anti-retroviral treatment on the reconstitution ...

    African Journals Online (AJOL)

    Objectives: To ascertain the effect of interrupted ART on reconstitution of CD4+ and CD8+ T sub-sets in TB patients. Methods: Participants with HIV (CD4>350 cells/μL) and TB were recruited under a larger phase 3 open label randomised controlled clinical trial. The CD45RO and CD62L markers were measured on CD4+ ...

  3. Finite Time Fault Tolerant Control for Robot Manipulators Using Time Delay Estimation and Continuous Nonsingular Fast Terminal Sliding Mode Control.

    Science.gov (United States)

    Van, Mien; Ge, Shuzhi Sam; Ren, Hongliang

    2016-04-28

    In this paper, a novel finite time fault tolerant control (FTC) is proposed for uncertain robot manipulators with actuator faults. First, a finite time passive FTC (PFTC) based on a robust nonsingular fast terminal sliding mode control (NFTSMC) is investigated. Be analyzed for addressing the disadvantages of the PFTC, an AFTC are then investigated by combining NFTSMC with a simple fault diagnosis scheme. In this scheme, an online fault estimation algorithm based on time delay estimation (TDE) is proposed to approximate actuator faults. The estimated fault information is used to detect, isolate, and accommodate the effect of the faults in the system. Then, a robust AFTC law is established by combining the obtained fault information and a robust NFTSMC. Finally, a high-order sliding mode (HOSM) control based on super-twisting algorithm is employed to eliminate the chattering. In comparison to the PFTC and other state-of-the-art approaches, the proposed AFTC scheme possess several advantages such as high precision, strong robustness, no singularity, less chattering, and fast finite-time convergence due to the combined NFTSMC and HOSM control, and requires no prior knowledge of the fault due to TDE-based fault estimation. Finally, simulation results are obtained to verify the effectiveness of the proposed strategy.

  4. Soft real-time EPICS extensions for fast control: A case study applied to a TCV equilibrium algorithm

    International Nuclear Information System (INIS)

    Castro, R.; Romero, J.A.; Vega, J.; Nieto, J.; Ruiz, M.; Sanz, D.; Barrera, E.; De Arcas, G.

    2014-01-01

    Highlights: • Implementation of a soft real-time control system based on EPICS technology. • High data throughput system control implementation. • GPU technology applied to fast control. • EPICS fast control based solution. • Fast control and data acquisition in Linux. - Abstract: For new control systems development, ITER distributes CODAC Core System that is a software package based on Linux RedHat, and includes EPICS (Experimental Physics and Industrial Control System) as software control system solution. EPICS technology is being widely used for implementing control systems in research experiments and it is a very well tested technology, but presents important lacks to meet fast control requirements. To manage and process massive amounts of acquired data, EPICS requires additional functions such as: data block oriented transmissions, links with speed-optimized data buffers and synchronization mechanisms not based on system interruptions. This EPICS limitation turned out clearly during the development of the Fast Plant System Controller Prototype for ITER based on PXIe platform. In this work, we present a solution that, on the one hand, is completely compatible and based on EPCIS technology, and on the other hand, extends EPICS technology for implementing high performance fast control systems with soft-real time characteristics. This development includes components such as: data acquisition, processing, monitoring, data archiving, and data streaming (via network and shared memory). Additionally, it is important to remark that this system is compatible with multiple Graphics Processing Units (GPUs) and is able to integrate MatLab code through MatLab engine connections. It preserves EPICS modularity, enabling system modification or extension with a simple change of configuration, and finally it enables parallelization based on data distribution to different processing components. With the objective of illustrating the presented solution in an actual

  5. Data processing system for real-time control

    International Nuclear Information System (INIS)

    Oasa, K.; Mochizuki, O.; Toyokawa, R.; Yahiro, K.

    1983-01-01

    Real-time control, for large Tokamak JT-60, requires various data processings between diagnostic devices to control system. These processings require to high speed performance so that it aims at giving information necessary for feedback control during discharges. Then, the architecture of this system has hierachical structure of processors. These processors are connected each other by the CAMAC modules and the optical communication network, which is the 5 M bytes/second CAMAC serial highway. This system has two kinds of intelligences for this purpose. One is ACM-PU pairs in some torus hall crates which has a microcomputerized auxiliary controller and a preprocessing unit. Other is real-time processor which has a minicomputer and preprocessing unit. Most of the real-time processing, for example Abel inversion are characteristic to the diagnostic devices. Such a processing is carried out by an ACM-PU pair in the crate dedicated to the diagnostic device. Some processings, however, are also necessary which compute secondary parameters as functions of primary parameters. A typical example is Zeff, which is a function of Te, Ne and bremsstrahluny intensity. The real-time processor is equipped for such secondary processings and transfer the results. Preprocessing unit -PU- attached to ACM and real-time processor contains a signal processor, which executes in parallel such function as move, add and multiply during one micro-instruction cycle of 200 nsec. According to the progress of the experiment, more high speed processing are required, so the authors developed the PU-X module that contains multi signal processors. After a shot, inter-shot-processor which consists of general-purpose computers, gathers data into the database, then analyze them, and improve these processes to more effective

  6. Complex-Vector Time-Delay Control of Power Converters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, P. C.; Tang, Y.

    2008-01-01

    Precise controlling of current produced by power converters is an important topic that has attracted interests over the last few decades. With the recent proliferation of grid-tied converters where the control of power flow is indirectly governed by the accuracy of current tracking, motivation...... since only a small amount of memory space for storing time-delayed values and simple arithmetic computations are needed for its physical realization. In addition to that, other advantages of the scheme include its abilities to compensate for negative-sequence, load and grid harmonic components using...

  7. Interruption of Onchocerca volvulus transmission in Northern Venezuela.

    Science.gov (United States)

    Convit, Jacinto; Schuler, Harland; Borges, Rafael; Olivero, Vimerca; Domínguez-Vázquez, Alfredo; Frontado, Hortencia; Grillet, María E

    2013-10-07

    Onchocerciasis is caused by Onchocerca volvulus and transmitted by Simulium species (black flies). In the Americas, the infection has been previously described in 13 discrete regional foci distributed among six countries (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela) where more than 370,000 people are currently considered at risk. Since 2001, disease control in Venezuela has relied on the mass drug administration to the at-risk communities. This report provides empirical evidence of interruption of Onchocerca volvulus transmission by Simulium metallicum in 510 endemic communities from two Northern foci of Venezuela, after 10-12 years of 6-monthly Mectizan (ivermectin) treatment to all the eligible residents. In-depth entomologic and epidemiologic surveys were serially conducted from 2001-2012 in selected (sentinel and extra-sentinel) communities from the North-central (NC) and North-east (NE) onchocerciasis foci of Venezuela in order to monitor the impact of ivermectin treatment. From 2007-2009, entomological indicators in both foci confirmed that 0 out of 112,637 S. metallicum females examined by PCR contained L3 infection in insect heads. The upper bound of the 95% confidence intervals of the infective rate of the vector reached values below 1% by 2009 (NC) and 2012 (NE). Additionally, after 14 (NC) and 22 (NE) rounds of treatment, the seasonal transmission potential (±UL CIs) of S. metallicum was under the critical threshold of 20 L3 per person per season. Serological analysis in school children Venezuela.

  8. Least squares reverse time migration of controlled order multiples

    Science.gov (United States)

    Liu, Y.

    2016-12-01

    Imaging using the reverse time migration of multiples generates inherent crosstalk artifacts due to the interference among different order multiples. Traditionally, least-square fitting has been used to address this issue by seeking the best objective function to measure the amplitude differences between the predicted and observed data. We have developed an alternative objective function by decomposing multiples into different orders to minimize the difference between Born modeling predicted multiples and specific-order multiples from observational data in order to attenuate the crosstalk. This method is denoted as the least-squares reverse time migration of controlled order multiples (LSRTM-CM). Our numerical examples demonstrated that the LSRTM-CM can significantly improve image quality compared with reverse time migration of multiples and least-square reverse time migration of multiples. Acknowledgments This research was funded by the National Nature Science Foundation of China (Grant Nos. 41430321 and 41374138).

  9. Real Time Implementation of Incremental Fuzzy Logic Controller for Gas Pipeline Corrosion Control

    Directory of Open Access Journals (Sweden)

    Gopalakrishnan Jayapalan

    2014-01-01

    Full Text Available A robust virtual instrumentation based fuzzy incremental corrosion controller is presented to protect metallic gas pipelines. Controller output depends on error and change in error of the controlled variable. For corrosion control purpose pipe to soil potential is considered as process variable. The proposed fuzzy incremental controller is designed using a very simple control rule base and the most natural and unbiased membership functions. The proposed scheme is tested for a wide range of pipe to soil potential control. Performance comparison between the conventional proportional integral type and proposed fuzzy incremental controller is made in terms of several performance criteria such as peak overshoot, settling time, and rise time. Result shows that the proposed controller outperforms its conventional counterpart in each case. Designed controller can be taken in automode without waiting for initial polarization to stabilize. Initial startup curve of proportional integral controller and fuzzy incremental controller is reported. This controller can be used to protect any metallic structures such as pipelines, tanks, concrete structures, ship, and offshore structures.

  10. Fuzzy Coordinated PI Controller: Application to the Real-Time Pressure Control Process

    Directory of Open Access Journals (Sweden)

    N. Kanagaraj

    2008-01-01

    Full Text Available This paper presents the real-time implementation of a fuzzy coordinated classical PI control scheme for controlling the pressure in a pilot pressure tank system. The fuzzy system has been designed to track the variation parameters in a feedback loop and tune the classical controller to achieve a better control action for load disturbances and set point changes. The error and process inputs are chosen as the inputs of fuzzy system to tune the conventional PI controller according to the process condition. This online conventional controller tuning technique will reduce the human involvement in controller tuning and increase the operating range of the conventional controller. The proposed control algorithm is experimentally implemented for the real-time pressure control of a pilot air tank system and validated using a high-speed 32-bit ARM7 embedded microcontroller board (ATMEL AT91M55800A. To demonstrate the performance of the fuzzy coordinated PI control scheme, results are compared with a classical PI and PI-type fuzzy control method. It is observed that the proposed controller structure is able to quickly track the parameter variation and perform better in load disturbances and also for set point changes.

  11. Time-delayed feedback control of coherence resonance chimeras

    Science.gov (United States)

    Zakharova, Anna; Semenova, Nadezhda; Anishchenko, Vadim; Schöll, Eckehard

    2017-11-01

    Using the model of a FitzHugh-Nagumo system in the excitable regime, we investigate the influence of time-delayed feedback on noise-induced chimera states in a network with nonlocal coupling, i.e., coherence resonance chimeras. It is shown that time-delayed feedback allows for the control of the range of parameter values where these chimera states occur. Moreover, for the feedback delay close to the intrinsic period of the system, we find a novel regime which we call period-two coherence resonance chimera.

  12. Upgrade of the COMPASS tokamak real-time control system

    Czech Academy of Sciences Publication Activity Database

    Janky, Filip; Havlíček, Josef; Batista, A.J.N.; Kudláček, Ondřej; Seidl, Jakub; Neto, A.C.; Pipek, Jan; Hron, Martin; Mikulín, Ondřej; Duarte, A.S.; Carvalho, B.B.; Stöckel, Jan; Pánek, Radomír

    2014-01-01

    Roč. 89, č. 3 (2014), s. 186-194 ISSN 0920-3796 R&D Projects: GA ČR GAP205/11/2470; GA MŠk 7G10072; GA MŠk(CZ) LM2011021 Institutional support: RVO:61389021 Keywords : Real-time * Feedback control * Real-time framework * MARTe * COMPASS tokamak Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.152, year: 2014 http://www.sciencedirect.com/science/article/pii/S0920379613007564

  13. A Feedback Optimal Control Algorithm with Optimal Measurement Time Points

    Directory of Open Access Journals (Sweden)

    Felix Jost

    2017-02-01

    Full Text Available Nonlinear model predictive control has been established as a powerful methodology to provide feedback for dynamic processes over the last decades. In practice it is usually combined with parameter and state estimation techniques, which allows to cope with uncertainty on many levels. To reduce the uncertainty it has also been suggested to include optimal experimental design into the sequential process of estimation and control calculation. Most of the focus so far was on dual control approaches, i.e., on using the controls to simultaneously excite the system dynamics (learning as well as minimizing a given objective (performing. We propose a new algorithm, which sequentially solves robust optimal control, optimal experimental design, state and parameter estimation problems. Thus, we decouple the control and the experimental design problems. This has the advantages that we can analyze the impact of measurement timing (sampling independently, and is practically relevant for applications with either an ethical limitation on system excitation (e.g., chemotherapy treatment or the need for fast feedback. The algorithm shows promising results with a 36% reduction of parameter uncertainties for the Lotka-Volterra fishing benchmark example.

  14. New magnetic real time shape control for MAST

    Energy Technology Data Exchange (ETDEWEB)

    Pangione, L., E-mail: luigi.pangione@ccfe.ac.uk [EURATOM/CCFE Fusion Association – Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); McArdle, G.; Storrs, J. [EURATOM/CCFE Fusion Association – Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2013-10-15

    Highlights: ► New magnetic shape control system has been implemented. ► It has been intensively tested in a simulation environment. ► A tool chain to produce LTI model and simulate its behaviour has been implemented. ► Experimental results are shown. -- Abstract: The Mega Ampere Spherical Tokamak (MAST) real time plasma position controller is based on an optical linear camera placed on the mid plane of the vessel. This solution has the advantage of being a direct observation of the D{sub α} emissions coming from the interaction between the boundary of the plasma and neutral gas, but, on the other hand, it restricts the control to the outer radius of the plasma only. A complete chain of tools has been set up to implement, test and simulate a new real time magnetic plasma shape controller based on the rtEFIT code. The complete working path consists of three elements: a linear static relationship between control parameters and current demands, a linear state space model needed to represent the plasma dynamic response in closed loop simulations, and the possibility to run simulations inside the Plasma Control System (PCS). The linear relationship has been calculated using the FIESTA code, which is developed using Matlab at CCFE. The linear state space model was generated using the CREATE-L code developed by the CREATE Consortium. It has already been successfully used to model JET, FTU and TCV tokamaks. Using this working path many simulations have been carried out allowing fine tuning of the control gains before the real experiment. The simulation testing includes the plasma shape control law as implemented in PCS itself, so intensive debugging has been possible prior to operation. Successful control using rtEFIT was established in the second dedicated experiment during the MAST 2011–12 campaign. This work is a stepping stone towards divertor control which is ultimately intended for application to the super-X divertor in the MAST Upgrade experiment.

  15. Partial control of chaotic transients using escape times

    International Nuclear Information System (INIS)

    Sabuco, Juan; Zambrano, Samuel; Sanjuan, Miguel A F

    2010-01-01

    The partial control technique allows one to keep the trajectories of a dynamical system inside a region where there is a chaotic saddle and from which nearly all the trajectories diverge. Its main advantage is that this goal is achieved even if the corrections applied to the trajectories are smaller than the action of environmental noise on the dynamics, a counterintuitive result that is obtained by using certain safe sets. Using the Henon map as a paradigm, we show here the deep relationship between the safe sets and the sets of points with different escape times, the escape time sets. Furthermore, we show that it is possible to find certain extended safe sets that can be used instead of the safe sets in the partial control technique. Numerical simulations confirm our findings and show that in some situations, the use of extended safe sets can be more advantageous.

  16. Real time control of the sawtooth period using EC launchers

    International Nuclear Information System (INIS)

    Paley, J I; Felici, F; Coda, S; Goodman, T P; Piras, F

    2009-01-01

    Tokamak plasmas operating at high performance are limited by several MHD instabilities. The sawtooth instability limits the core plasma pressure and can drive the neoclassical tearing mode unstable, but also prevents accumulation of impurities in the core. Electron cyclotron heating and current drive systems can be used to modify the local current profile and therefore tailor the sawtooth period. This paper reports on demonstrations of continuous real time feedback control of the sawtooth period by varying the EC injection angle.

  17. Upgrade of the RFX-mod real time control system

    Energy Technology Data Exchange (ETDEWEB)

    Manduchi, G., E-mail: gabriele.manduchi@igi.cnr.it [Consorzio RFX, Euratom-ENEA Association, Corso Stati Uniti 4, Padova 35127 (Italy); Barbalace, A.; Luchetta, A.; Soppelsa, A.; Taliercio, C.; Zampiva, E. [Consorzio RFX, Euratom-ENEA Association, Corso Stati Uniti 4, Padova 35127 (Italy)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The paper describes the experience in running the real-time control system of RFX-mod. Black-Right-Pointing-Pointer It proposes a new architecture based multicore technology. Black-Right-Pointing-Pointer It analyzes two different solutions for data acquisition. Black-Right-Pointing-Pointer It discusses the effect of non simultaneous sampling in acquisition. Black-Right-Pointing-Pointer It provides some preliminary performance measurements. - Abstract: The real-time control system of RFX-mod, in operation since 2005, has been successful and has allowed several important achievements in the RFX physics research program. As a consequence of this fact, new control algorithms are under investigation, which are more demanding in terms of both enhanced computing power and reduced system latency, currently around 1.5 ms. For this reason, a major upgrade of the system is being considered, and a new architecture has been proposed, taking advantage of the rapid evolution of computer technology in the last years. The central component of the new architecture is a Linux-based multicore server, where individual cores replace the VME computers. The server is connected to the I/O via PCI-e based bus extenders, and every PCI-e connection is managed by a separate core. The system is supervised by MARTe, a software framework for real-time applications written in C++ and developed at JET and currently used for the JET vertical stabilization and in other fusion devices.

  18. Upgrade of the RFX-mod real time control system

    International Nuclear Information System (INIS)

    Manduchi, G.; Barbalace, A.; Luchetta, A.; Soppelsa, A.; Taliercio, C.; Zampiva, E.

    2012-01-01

    Highlights: ► The paper describes the experience in running the real-time control system of RFX-mod. ► It proposes a new architecture based multicore technology. ► It analyzes two different solutions for data acquisition. ► It discusses the effect of non simultaneous sampling in acquisition. ► It provides some preliminary performance measurements. - Abstract: The real-time control system of RFX-mod, in operation since 2005, has been successful and has allowed several important achievements in the RFX physics research program. As a consequence of this fact, new control algorithms are under investigation, which are more demanding in terms of both enhanced computing power and reduced system latency, currently around 1.5 ms. For this reason, a major upgrade of the system is being considered, and a new architecture has been proposed, taking advantage of the rapid evolution of computer technology in the last years. The central component of the new architecture is a Linux-based multicore server, where individual cores replace the VME computers. The server is connected to the I/O via PCI-e based bus extenders, and every PCI-e connection is managed by a separate core. The system is supervised by MARTe, a software framework for real-time applications written in C++ and developed at JET and currently used for the JET vertical stabilization and in other fusion devices.

  19. Real Time Energy Management Control Strategies for Hybrid Powertrains

    Science.gov (United States)

    Zaher, Mohamed Hegazi Mohamed

    In order to improve fuel efficiency and reduce emissions of mobile vehicles, various hybrid power-train concepts have been developed over the years. This thesis focuses on embedded control of hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy for continuous operations. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, or the motion is driven by gravitational force, or load driven. There are three main concepts for regernerative energy storing devices in hybrid vehicles: electric, hydraulic, and flywheel. The real time control challenge is to balance the system power demand from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle, while making optimal use of the energy saving opportunities in a given operational, often repetitive cycle. In the worst case scenario, only engine is used and hybrid system completely disabled. A rule based control is developed and tuned for different work cycles and linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the machine and its position via GPS, and maps them to the gains.

  20. Real-Time Energy Management Control for Hybrid Electric Powertrains

    Directory of Open Access Journals (Sweden)

    Mohamed Zaher

    2013-01-01

    Full Text Available This paper focuses on embedded control of a hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real-time energy management strategy. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in the opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, the motion is driven by gravitational force, or load driven. There are three main concepts for energy storing devices in hybrid vehicles: electric, hydraulic, and mechanical (flywheel. The real-time control challenge is to balance the system power demands from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle. In the worst-case scenario, only the engine is used and the hybrid system is completely disabled. A rule-based control algorithm is developed and is tuned for different work cycles and could be linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the work machine and its position via GPS and maps both of them to the gains.

  1. Progress in real-time feedback control systems in RFX

    Energy Technology Data Exchange (ETDEWEB)

    Barana, O.; Luchetta, A. E-mail: adriano.luchetta@igi.cnr.it; Manduchi, G.; Taliercio, C

    2004-06-01

    Major modifications of the RFX load assembly and power supplies are in progress to allow extensive active control schemes, such as equilibrium and plasma position control and innovative control of the MHD modes. The digital control system is implemented in VME64 using a distributed architecture. The use of a 'stable' operating system that is likely to survive some generations of processors can help coping with evolution of technology. PowerPC and Pentium processors were thus considered as candidates and tested and the first one has been selected due to the better performance in floating point computation. Wind River VxWorks has been chosen as real-time operating system. 100 Mbit switched Ethernet has been evaluated for real-time communication by using the user datagram protocol (UDP). Measurements have been executed on a prototype system to assess data transfer latency, jitter and reliability and the results confirm that the solution is suitable for the application. The paper describes in detail the reasons for the choice in the hardware components. Results from several tests comparing the performance of different solutions are also provided.

  2. Trajectory-tracking control of underwater inspection robot for nuclear reactor internals using Time Delay Control

    International Nuclear Information System (INIS)

    Park, Joon-Young; Cho, Byung-Hak; Lee, Jae-Kyung

    2009-01-01

    This paper addresses the trajectory control problem of an underwater inspection robot for nuclear reactor internals. From the viewpoint of control engineering, the trajectory control of the underwater robot is a difficult task due to its nonlinear dynamics, which includes various hydraulic forces such as buoyancy and hydrodynamic damping, the difference between the centres of gravity and buoyancy, and disturbances from a tether cable. To solve such problems, we applied Time Delay Control to the underwater robot. This control law has a very simple structure not requiring nonlinear plant dynamics, and was proven to be highly robust against nonlinearities, uncertainties and disturbances. We confirmed its effectiveness through experiments.

  3. Real-Time Structural Overload Control via Control Allocation Optimization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This control methodology utilizes real-time vehicle structural load and shape measurements to actively respond to and protect against vehicle damage due to...

  4. Arithmetical unit, interrupt hardware and input-output channel for the computer Bel

    International Nuclear Information System (INIS)

    Fyroe, Karl-Johan

    1969-01-01

    This thesis contains a description of a small general purpose computer using characters, variable word-length and two-address instructions and which is working in decimal (NBCD). We have realized three interruption lines with a fixed priority. The channel is selective and has generally access to the entire memory. Using slow IO-devices, time sharing is possible between the channel and the processor in the central memory buffer area. (author) [fr

  5. Methodology for the study of the dolomite porosity in essay of interrupted sulfation

    OpenAIRE

    Ávila, Ivonete; Crnkovic, Paula M.; Milioli, Fernando E.

    2010-01-01

    The aim of this work is to propose a methodology to evaluate the evolution of the pore blockage of limestone during the sulfation reaction. The experiments were performed for a national limestone (dolomite) with average particle size of 545 μm in interrupted sulfation tests were conducted at seven different times and at three different temperatures of the process. The empirical data were obtained from porosimetry tests to establish BET surface area, volume and average size of pore and di...

  6. Using real-time stereopsis for mobile robot control

    Science.gov (United States)

    Bonasso, R. P.; Nishihara, H. K.

    1991-02-01

    This paper describes on-going work in using range and motion data generated at video-frame rates as the basis for long-range perception in a mobile robot. A current approach in the artificial intelligence community to achieve timecritical perception for situated reasoning is to use low-level perception for motor reflex-like activity and higher-level but more computationally intense perception for path planning reconnaissance and retrieval activities. Typically inclinometers and a compass or an infra-red beacon system provide stability and orientation maintenance and ultrasonic or infra-red sensors serve as proximity detectors for obstacle avoidance. For distant ranging and area occupancy determination active imaging systems such as laser scanners can be prohibitivtly expensive and heretofore passive systems typically performed more slowly than the cycle time of the control system causing the robot to halt periodically along its way. However a recent stereo system developed by Nishihara known as PRISM (Practical Real-time Imaging Stereo Matcher) matches stereo pairs using a sign-correlation technique that gives range and motion at video frame rates. We are integrating this technique with constant-time control software for distant ranging and object detection at a speed that is comparable with the cycle-times of the low-level sensors. Possibilities for a variety of uses in a leader-follower mobile robot situation are discussed.

  7. Complexity Variability Assessment of Nonlinear Time-Varying Cardiovascular Control

    Science.gov (United States)

    Valenza, Gaetano; Citi, Luca; Garcia, Ronald G.; Taylor, Jessica Noggle; Toschi, Nicola; Barbieri, Riccardo

    2017-02-01

    The application of complex systems theory to physiology and medicine has provided meaningful information about the nonlinear aspects underlying the dynamics of a wide range of biological processes and their disease-related aberrations. However, no studies have investigated whether meaningful information can be extracted by quantifying second-order moments of time-varying cardiovascular complexity. To this extent, we introduce a novel mathematical framework termed complexity variability, in which the variance of instantaneous Lyapunov spectra estimated over time serves as a reference quantifier. We apply the proposed methodology to four exemplary studies involving disorders which stem from cardiology, neurology and psychiatry: Congestive Heart Failure (CHF), Major Depression Disorder (MDD), Parkinson’s Disease (PD), and Post-Traumatic Stress Disorder (PTSD) patients with insomnia under a yoga training regime. We show that complexity assessments derived from simple time-averaging are not able to discern pathology-related changes in autonomic control, and we demonstrate that between-group differences in measures of complexity variability are consistent across pathologies. Pathological states such as CHF, MDD, and PD are associated with an increased complexity variability when compared to healthy controls, whereas wellbeing derived from yoga in PTSD is associated with lower time-variance of complexity.

  8. Flexible structure control experiments using a real-time workstation for computer-aided control engineering

    Science.gov (United States)

    Stieber, Michael E.

    1989-01-01

    A Real-Time Workstation for Computer-Aided Control Engineering has been developed jointly by the Communications Research Centre (CRC) and Ruhr-Universitaet Bochum (RUB), West Germany. The system is presently used for the development and experimental verification of control techniques for large space systems with significant structural flexibility. The Real-Time Workstation essentially is an implementation of RUB's extensive Computer-Aided Control Engineering package KEDDC on an INTEL micro-computer running under the RMS real-time operating system. The portable system supports system identification, analysis, control design and simulation, as well as the immediate implementation and test of control systems. The Real-Time Workstation is currently being used by CRC to study control/structure interaction on a ground-based structure called DAISY, whose design was inspired by a reflector antenna. DAISY emulates the dynamics of a large flexible spacecraft with the following characteristics: rigid body modes, many clustered vibration modes with low frequencies and extremely low damping. The Real-Time Workstation was found to be a very powerful tool for experimental studies, supporting control design and simulation, and conducting and evaluating tests withn one integrated environment.

  9. Integrated project scheduling and staff assignment with controllable processing times.

    Science.gov (United States)

    Fernandez-Viagas, Victor; Framinan, Jose M

    2014-01-01

    This paper addresses a decision problem related to simultaneously scheduling the tasks in a project and assigning the staff to these tasks, taking into account that a task can be performed only by employees with certain skills, and that the length of each task depends on the number of employees assigned. This type of problems usually appears in service companies, where both tasks scheduling and staff assignment are closely related. An integer programming model for the problem is proposed, together with some extensions to cope with different situations. Additionally, the advantages of the controllable processing times approach are compared with the fixed processing times. Due to the complexity of the integrated model, a simple GRASP algorithm is implemented in order to obtain good, approximate solutions in short computation times.

  10. Integrated Project Scheduling and Staff Assignment with Controllable Processing Times

    Directory of Open Access Journals (Sweden)

    Victor Fernandez-Viagas

    2014-01-01

    Full Text Available This paper addresses a decision problem related to simultaneously scheduling the tasks in a project and assigning the staff to these tasks, taking into account that a task can be performed only by employees with certain skills, and that the length of each task depends on the number of employees assigned. This type of problems usually appears in service companies, where both tasks scheduling and staff assignment are closely related. An integer programming model for the problem is proposed, together with some extensions to cope with different situations. Additionally, the advantages of the controllable processing times approach are compared with the fixed processing times. Due to the complexity of the integrated model, a simple GRASP algorithm is implemented in order to obtain good, approximate solutions in short computation times.

  11. Timing reference generators and chopper controllers for neutron sources

    International Nuclear Information System (INIS)

    Nelson, R.; Merl, R.; Rose, C.

    2001-01-01

    Due to AC-power-grid frequency fluctuations, the designers for accelerator-based spallation-neutron facilities have worked to optimize the competing and contrasting demands of accelerator and neutron chopper performance. Powerful new simulation techniques have enabled the modeling of the timing systems that integrate chopper controllers and chopper hardware. For the first time, we are able to quantitatively access the tradeoffs between these two constraints and design or upgrade a facility to optimize total system performance. Thus, at LANSCE, we now operate multiple chopper systems and the accelerator as simple slaves to a single master-timing-reference generator. For the SNS we recommend a similar system that is somewhat less tightly coupled to the power grid. (author)

  12. The effect of interruptions and breaks on insight and impasses: Do you need a break right now?

    NARCIS (Netherlands)

    Beeftink, F.; van Eerde, W.; Rutte, C.G.

    2008-01-01

    Some time away from a problem, or incubation time, is found to be beneficial to creative problem solving. But are interruptions as equally helpful as breaks? An experiment was conducted to gain more insight into the differences between imposed and self-initiated breaks, and their effects on

  13. Work time control, sleep & accident risk: A prospective cohort study.

    Science.gov (United States)

    Tucker, Philip; Albrecht, Sophie; Kecklund, Göran; Beckers, Debby G J; Leineweber, Constanze

    We examined whether the beneficial impact of work time control (WTC) on sleep leads to lower accident risk, using data from a nationally representative survey conducted in Sweden. Logistic regressions examined WTC in 2010 and 2012 as predictors of accidents occurring in the subsequent 2 years (N = 4840 and 4337, respectively). Sleep disturbance and frequency of short sleeps in 2012 were examined as potential mediators of the associations between WTC in 2010 and subsequent accidents as reported in 2014 (N = 3636). All analyses adjusted for age, sex, education, occupational category, weekly work hours, shift work status, job control and perceived accident risk at work. In both waves, overall WTC was inversely associated with accidents (p = 0.048 and p = 0.038, respectively). Analyses of the sub-dimensions of WTC indicated that Control over Daily Hours (influence over start and finish times, and over length of shift) did not predict accidents in either wave, while Control over Time-off (CoT; influence over taking breaks, running private errands during work and taking paid leave) predicted fewer accidents in both waves (p = 0.013 and p = 0.010). Sleep disturbance in 2012 mediated associations between WTC/CoT in 2010 and accidents in 2014, although effects' sizes were small (effectWTC = -0.006, 95% confidence interval [CI] = -0.018 to -0.001; effectCoT = -0.009, 95%CI = -0.022 to -0.001; unstandardized coefficients), with the indirect effects of sleep disturbance accounting for less than 5% of the total direct and indirect effects. Frequency of short sleeps was not a significant mediator. WTC reduces the risk of subsequently being involved in an accident, although sleep may not be a strong component of the mechanism underlying this association.

  14. Effects of interruptible natural gas service: Winter 1989--1990

    International Nuclear Information System (INIS)

    1991-07-01

    During the extreme winter conditions experienced in December 1989, petroleum products showed dramatic price increases. Supply of certain products such as propane reached critical levels. Numerous factors contributed to the heating fuel situation, including well freeze-ups and refinery problems, as well as difficulties associated with delivery of the product. An area of concern identified in the ensuing debates was the impact of customer requirements for petroleum products resulting from curtailment of natural gas purchases under interruptible contracts. The lower rates associated with interruptible contracts make them an attractive choice for electric utilities. However, they require that the customer be prepared to obtain adequate fuel supplies in the event of curtailments. Electric utilities prepare for these contingencies with stocks of alternative fuels. Particularly in cold climates, interruptible has contracts are part of doing business. The extent and duration of the interruptions faced by customers relate principally to weather factors. Previous EIA studies investigated on a national level the causes of the dramatic price increases seen in petroleum product markets in the 1989--1990 heating season. This study is in response to a request from Senator Timothy Wirth, Chairman, Subcommittee on Energy Regulation and Conservation, to study in detail the impact of interruptible natural gas contracts as one of the factors cited as contributing to the price increases. A copy of the letter requesting the study is contained in Appendix A

  15. Response to planned treatment interruptions in HIV infection varies across childhood

    DEFF Research Database (Denmark)

    NN, NN; Valerius, Niels Henrik

    2010-01-01

    OBJECTIVE: To evaluate clinical, immunological and virological consequences of CD4-guided antiretroviral therapy (ART) planned treatment interruptions (PTIs) compared with continuous therapy in children with chronic HIV infection in the Paediatric European Network for Treatment of AIDS 11 trial......) or PTI (56). In PTI, ART was restarted if confirmed CD4% was less than 20% or more than 48 weeks had been spent off ART. The primary outcome was Centers for Disease Control and Prevention (CDC) stage C event, death or CD4% less than 15% (and CD4 cell count less than 200 cells/microl for children aged 7......-term follow-up in Paediatric European Network for Treatment of AIDS 11 trial are ongoing. Further research into the role of treatment interruption in children is required, particularly, as guidelines now recommend early ART for all infected infants....

  16. Quality Control Procedure Based on Partitioning of NMR Time Series

    Directory of Open Access Journals (Sweden)

    Michał Staniszewski

    2018-03-01

    Full Text Available The quality of the magnetic resonance spectroscopy (MRS depends on the stability of magnetic resonance (MR system performance and optimal hardware functioning, which ensure adequate levels of signal-to-noise ratios (SNR as well as good spectral resolution and minimal artifacts in the spectral data. MRS quality control (QC protocols and methodologies are based on phantom measurements that are repeated regularly. In this work, a signal partitioning algorithm based on a dynamic programming (DP method for QC assessment of the spectral data is described. The proposed algorithm allows detection of the change points—the abrupt variations in the time series data. The proposed QC method was tested using the simulated and real phantom data. Simulated data were randomly generated time series distorted by white noise. The real data were taken from the phantom quality control studies of the MRS scanner collected for four and a half years and analyzed by LCModel software. Along with the proposed algorithm, performance of various literature methods was evaluated for the predefined number of change points based on the error values calculated by subtracting the mean values calculated for the periods between the change-points from the original data points. The time series were checked using external software, a set of external methods and the proposed tool, and the obtained results were comparable. The application of dynamic programming in the analysis of the phantom MRS data is a novel approach to QC. The obtained results confirm that the presented change-point-detection tool can be used either for independent analysis of MRS time series (or any other or as a part of quality control.

  17. Control of beam size and polarization time in PEP

    International Nuclear Information System (INIS)

    Paterson, J.M.; Rees, J.R.; Wiedemann, H.

    1975-07-01

    In this report we describe a method of controlling beam size in which the focusing functions are not altered with beam energy but the curvature function is drastically altered in a few locations which comprise only a very small fraction of the circumference. As will be described in the following paper we are proposing to control the quantum excitation and radiation damping of the particles by means of special excitation magnets or /open quotes/wigglers/close quotes/. Since the mean square energy deviation and radial beam emittance are proportional approximately to E/sup 2//l angle/G/sup 3//r angle//l angle/G/sup 2//r angle//sup /minus/1 while the damping times are proportional to (E/sup 3//l angle/G/sup 2//r angle/)/sup /minus/1/, it is possible to achieve constant beam size in a constant focusing configuration while the damping times vary roughly as E/sup /minus/2/. In addition, it is possible to reduce the beam polarization time with these devices. A scheme for beam-size and damping control based on the same principle was described by M. Bassetti about a year ago, in which all of the storage-ring bending magnets were involved as wigglers, and a substantial increase in magnet cost resulted. The consequences for polarization times were not explored. The design formulae are derived and two specific applications to the PEP design in which the wigglers are installed in three of the six 5-m straight sections are described with attention given to practical magnet design, synchrotron radiation handling and other matters. 5 refs., 4 figs., 1 tab

  18. Real-time statistical quality control and ARM

    International Nuclear Information System (INIS)

    Blough, D.K.

    1992-05-01

    An important component of the Atmospheric Radiation Measurement (ARM) Program is real-time quality control of data obtained from meteorological instruments. It is the goal of the ARM program to enhance the predictive capabilities of global circulation models by incorporating in them more detailed information on the radiative characteristics of the earth's atmosphere. To this end, a number of Cloud and Radiation Testbeds (CART's) will be built at various locations worldwide. Each CART will consist of an array of instruments designed to collect radiative data. The large amount of data obtained from these instruments necessitates real-time processing in order to flag outliers and possible instrument malfunction. The Bayesian dynamic linear model (DLM) proves to be an effective way of monitoring the time series data which each instrument generates. It provides a flexible yet powerful approach to detecting in real-time sudden shifts in a non-stationary multivariate time series. An application of these techniques to data arising from a remote sensing instrument to be used in the CART is provided. Using real data from a wind profiler, the ability of the DLM to detect outliers is studied. 5 refs

  19. Memory controllers for real-time embedded systems predictable and composable real-time systems

    CERN Document Server

    Akesson, Benny

    2012-01-01

      Verification of real-time requirements in systems-on-chip becomes more complex as more applications are integrated. Predictable and composable systems can manage the increasing complexity using formal verification and simulation.  This book explains the concepts of predictability and composability and shows how to apply them to the design and analysis of a memory controller, which is a key component in any real-time system. This book is generally intended for readers interested in Systems-on-Chips with real-time applications.   It is especially well-suited for readers looking to use SDRAM memories in systems with hard or firm real-time requirements. There is a strong focus on real-time concepts, such as predictability and composability, as well as a brief discussion about memory controller architectures for high-performance computing. Readers will learn step-by-step how to go from an unpredictable SDRAM memory, offering highly variable bandwidth and latency, to a predictable and composable shared memory...

  20. Effects of sport expertise on representational momentum during timing control.

    Science.gov (United States)

    Nakamoto, Hiroki; Mori, Shiro; Ikudome, Sachi; Unenaka, Satoshi; Imanaka, Kuniyasu

    2015-04-01

    Sports involving fast visual perception require players to compensate for delays in neural processing of visual information. Memory for the final position of a moving object is distorted forward along its path of motion (i.e., "representational momentum," RM). This cognitive extrapolation of visual perception might compensate for the neural delay in interacting appropriately with a moving object. The present study examined whether experienced batters cognitively extrapolate the location of a fast-moving object and whether this extrapolation is associated with coincident timing control. Nine expert and nine novice baseball players performed a prediction motion task in which a target moved from one end of a straight 400-cm track at a constant velocity. In half of the trials, vision was suddenly occluded when the target reached the 200-cm point (occlusion condition). Participants had to press a button concurrently with the target arrival at the end of the track and verbally report their subjective assessment of the first target-occluded position. Experts showed larger RM magnitude (cognitive extrapolation) than did novices in the occlusion condition. RM magnitude and timing errors were strongly correlated in the fast velocity condition in both experts and novices, whereas in the slow velocity condition, a significant correlation appeared only in experts. This suggests that experts can cognitively extrapolate the location of a moving object according to their anticipation and, as a result, potentially circumvent neural processing delays. This process might be used to control response timing when interacting with moving objects.

  1. Time Course of Brain Network Reconfiguration Supporting Inhibitory Control.

    Science.gov (United States)

    Popov, Tzvetan; Westner, Britta U; Silton, Rebecca L; Sass, Sarah M; Spielberg, Jeffrey M; Rockstroh, Brigitte; Heller, Wendy; Miller, Gregory A

    2018-05-02

    Hemodynamic research has recently clarified key nodes and links in brain networks implementing inhibitory control. Although fMRI methods are optimized for identifying the structure of brain networks, the relatively slow temporal course of fMRI limits the ability to characterize network operation. The latter is crucial for developing a mechanistic understanding of how brain networks shift dynamically to support inhibitory control. To address this critical gap, we applied spectrally resolved Granger causality (GC) and random forest machine learning tools to human EEG data in two large samples of adults (test sample n = 96, replication sample n = 237, total N = 333, both sexes) who performed a color-word Stroop task. Time-frequency analysis confirmed that recruitment of inhibitory control accompanied by slower behavioral responses was related to changes in theta and alpha/beta power. GC analyses revealed directionally asymmetric exchanges within frontal and between frontal and parietal brain areas: top-down influence of superior frontal gyrus (SFG) over both dorsal ACC (dACC) and inferior frontal gyrus (IFG), dACC control over middle frontal gyrus (MFG), and frontal-parietal exchanges (IFG, precuneus, MFG). Predictive analytics confirmed a combination of behavioral and brain-derived variables as the best set of predictors of inhibitory control demands, with SFG theta bearing higher classification importance than dACC theta and posterior beta tracking the onset of behavioral response. The present results provide mechanistic insight into the biological implementation of a psychological phenomenon: inhibitory control is implemented by dynamic routing processes during which the target response is upregulated via theta-mediated effective connectivity within key PFC nodes and via beta-mediated motor preparation. SIGNIFICANCE STATEMENT Hemodynamic neuroimaging research has recently clarified regional structures in brain networks supporting inhibitory control. However, due to

  2. A simplified controller and detailed dynamics of constant off-time peak current control

    Science.gov (United States)

    Van den Bossche, Alex; Dimitrova, Ekaterina; Valchev, Vencislav; Feradov, Firgan

    2017-09-01

    A fast and reliable current control is often the base of power electronic converters. The traditional constant frequency peak control is unstable above 50 % duty ratio. In contrast, the constant off-time peak current control (COTCC) is unconditionally stable and fast, so it is worth analyzing it. Another feature of the COTCC is that one can combine a current control together with a current protection. The time dynamics show a zero-transient response, even when the inductor changes in a wide range. It can also be modeled as a special transfer function for all frequencies. The article shows also that it can be implemented in a simple analog circuit using a wide temperature range IC, such as the LM2903, which is compatible with PV conversion and automotive temperature range. Experiments are done using a 3 kW step-up converter. A drawback is still that the principle does not easily fit in usual digital controllers up to now.

  3. Application of customer-interruption costs for optimum distribution planning

    International Nuclear Information System (INIS)

    Mok, Y.L.; Chung, T.S.

    1996-01-01

    We present a new methodology for obtaining optimum values of the integrated cost of utility investment with customer interruption in distribution planning for electric power systems by determining the reliability cost and worth of the distribution system. Reliability cost refers to investment cost of the utility in achieving a defined level of reliability. Reliability worth is the benefit gained by the utility customer from an increase of reliability. A computer program has been developed to determine comparative reliability indices for a typical distribution network. With the average interruption cost, outage duration, average disconnected load, cost data for distribution equipment, etc. being known, the relation between reliability cost, reliability worth and reliability at the specified load point are obtained. The optimum reliability of the distribution system is then determined from the minimum cost to the utility with customer interruption. The applicability of this approach is demonstrated by several practical networks. (Author)

  4. REAL TIME QUALITY CONTROL OF THE HEATSET OFFSET PRINTING PROCESS

    Directory of Open Access Journals (Sweden)

    Răzvan-George RĂCHERU

    2016-05-01

    Full Text Available Offset lithography is one of the most common ways of creating printed materials. Compared to other printing methods, offset printing is best suited for economically producing large volumes of high quality prints in a manner that requires little maintenance. Because of the high speed and the high volume of the printing press, we have to rely on automation for press control and not just to the printer’s eye. When printing an image that has more than one color, it is necessary to print each color separately and ensure each color overlaps the others precisely. If this is not done, the finished image will look fuzzy, blurred or "out of register". To help line the colors up correctly, a system of registration is necessary. Therefore, the use of an automated real time quality control system will result in a more consistent color for the customer and less waste for the printer.

  5. Modern linear control design a time-domain approach

    CERN Document Server

    Caravani, Paolo

    2013-01-01

    This book offers a compact introduction to modern linear control design.  The simplified overview presented of linear time-domain methodology paves the road for the study of more advanced non-linear techniques. Only rudimentary knowledge of linear systems theory is assumed - no use of Laplace transforms or frequency design tools is required. Emphasis is placed on assumptions and logical implications, rather than abstract completeness; on interpretation and physical meaning, rather than theoretical formalism; on results and solutions, rather than derivation or solvability.  The topics covered include transient performance and stabilization via state or output feedback; disturbance attenuation and robust control; regional eigenvalue assignment and constraints on input or output variables; asymptotic regulation and disturbance rejection. Lyapunov theory and Linear Matrix Inequalities (LMI) are discussed as key design methods. All methods are demonstrated with MATLAB to promote practical use and comprehension. ...

  6. Real-time software for the COMPASS tokamak plasma control

    Czech Academy of Sciences Publication Activity Database

    Valcárcel, D.F.; Duarte, A.S.; Neto, A.; Carvalho, I.S.; Carvalho, B.B.; Fernandes, H.; Sousa, J.; Sartori, F.; Janky, Filip; Cahyna, Pavel; Hron, Martin; Pánek, Radomír

    2010-01-01

    Roč. 85, 3-4 (2010), s. 470-473 ISSN 0920-3796. [IAEA Technical Meeting on Control, Data Acquisition and Remote Participation for Fusion Research/7th./. Aix – en – Provence, 15.06.2009-19.06.2009] Institutional research plan: CEZ:AV0Z20430508 Keywords : Real-time * ATCA * Data acquisition * Plasma control software Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.143, year: 2010 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3C-4YXMP1Y-3&_user=6542793&_coverDate=07%2F31%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000070123&_version=1&_urlVersion=0&_userid=6542793&md5=9005df0735c0dbb3a93a9c154b0d09c1&searchtype=a

  7. Radio controlled detonators and sequential real time blast applications

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, T.; Laboz, J.M. [Delta Caps International, Nice (France)

    1995-12-31

    Among the numerous technical evolutions in the blasting environment the authors are going to describe below the concept of electronic detonator sequenced by radio waves, and also its numerous applications. Three major technologies are used in the initiation environment: fused-initiated detonators; electric detonators; and non-electric detonators. The last two technologies were made available under multiple variants. Two major innovations are going to substantially change the way traditional detonators operate: pyrotechnic delays are replaced by electronic delays (greater accuracy); and triggering orders, passing through a cable, is now replaced by radio-waves transmission (possibility to do real time delay pattern). Such a new product provided all the features offered by current detonators, but also allows mastering specific cases that were difficult to control with the current technology, such as: vibration control; underground blast; and building demolition.

  8. Cheyne-Stokes respiration: hypoxia plus a deep breath that interrupts hypoxic drive, initiating cyclic breathing.

    Science.gov (United States)

    Guntheroth, Warren G

    2011-11-01

    In the 19th Century, Cheyne and Stokes independently reported cycles of respiration in patients with heart failure, beginning with apnea, followed by a few breaths. However Cheyne-Stokes respiration (C-SR) can also occur in healthy individuals with sleep, and was demonstrated in 1908 with voluntary hyperventilation, followed by apnea that Haldane blamed on hypoxia, subsequently called post-hyperventilation apnea. Additional theories explaining C-SR did not appear until 1954, based on control theory, specifically a feed-back regulator controlling CO(2). This certainly describes control of normal respiration, but to produce an unstable state such as C-SR requires either a very long transit time (3½ min) or an increase of the controller gain (13 times), physiologically improbable. There is general agreement that apnea initiates C-SR but that has not been well explained except for post-hyperventilation apnea, and that explanation is not compatible with a study by Nielsen and Smith in 1951. They plotted the effects of diminished oxygen on ventilation (V) in relation to CO(2) (Fig. 1). They found that the slope of V/CO(2) (gain) increased with hypoxia, but it flattened at a moderate CO(2) level and had nointercept with zero (apnea). It is also incompatible with our published findings in 1975 that showed that apnea did not occur until an extreme level of hypoxia occurred (the PO(2) fell below 10 mmHg), followed shortly by gasping. Much milder hypoxia underlies most cases of C-SR, when hypoxic drive replaces the normal CO(2)-based respiratory drive, in a failsafe role. I hypothesize that the cause of apnea is a brief interruption of hypoxic drive caused by a pulse of oxygen from a stronger than average breath, such as a sigh. The rapidity of onset of apnea in response to a pulse of oxygen, reflects the large pressure gradient for oxygen from air to lung with each breath, in contrast to CO(2). With apnea, there is a gradual fall in oxygen, resulting in a resumption of

  9. Combination of transcatheter arterial chemoembolization and interrupted dosing sorafenib improves patient survival in early–intermediate stage hepatocellular carcinoma

    Science.gov (United States)

    Lee, Teng-Yu; Lin, Chen-Chun; Chen, Chiung-Yu; Wang, Tsang-En; Lo, Gin-Ho; Chang, Chi-Sen; Chao, Yee

    2017-01-01

    Abstract Background/Objective: The survival benefit of treatment for unresectable hepatocellular carcinoma (HCC) with transcatheter arterial chemoembolization (TACE) combined with sorafenib remains uncertain. We compared the survival of patients treated with TACE and sorafenib with that of patients treated with TACE alone. Methods: This was a post hoc analysis of the Study in Asia of the Combination of TACE with Sorafenib in Patients with HCC (START) trial. All patients who received TACE and interrupted dosing of sorafenib for early or intermediate-stage HCC in Taiwan from 2009 to 2010 were recruited into the TACE and sorafenib group. They were randomly matched 1:1 by age, sex, Child–Pugh score, tumor size, tumor number, and tumor stage with patients from Taichung Veterans General Hospital in Taiwan who received TACE alone and who fulfilled the selection criteria of the START trial during the same time period (control group). Patient survival [cumulative incidence and hazard ratio (HR)] of the 2 groups were analyzed and compared. Results: The baseline characteristics of the 36 patients in each group were similar. Tumor response rates were significantly better in the TACE and sorafenib group (P < .04). Overall survival of the TACE and sorafenib group was also significantly better than that of the control (TACE alone) group over the 2 years [78%, 95% confidence interval (95% CI) 64–91 vs 49, 95% CI 32–66; P = .012]. In the multivariate regression analysis, TACE and sorafenib was found to be independently associated with a decreased risk of mortality (HR 0.33, 95% CI 0.12–0.89; P = .015). Multivariate stratified analyses verified this association in each patient subgroup (all HR < 1.0). Conclusion: With a high patient tolerance to an interrupted sorafenib dosing schedule, the combination of TACE with sorafenib was associated with improved overall survival in early–intermediate stage HCC when compared with treatment with TACE alone. PMID

  10. A PEMFC hybrid electric vehicle real time control system

    Science.gov (United States)

    Sun, Hongqiao

    In recent years, environmental friendly technologies and alternative energy solutions have drawn a lot of public attentions due to global energy crisis and pollution issues. Fuel cell (FC), a technology invented almost at the same time as the internal combustion (IC) engine, is now the focus of the automotive industry again. The fuel cell vehicle (FCV) has zero emission and its efficiency is significantly higher than the conventional IC engine power vehicles. Among a variety of FCV technologies, proton exchange membrane (PEM) FC vehicle appears to be far more attractive and mature. The prototype PEMFC vehicle has been developed and demonstrated to the public by nearly all the major automotive manufacturers in recent years. However, to the interest of the public research, publications and documentations on the PEMFC vehicle technology are rarely available due to its proprietary nature, which essentially makes it a secured technology. This dissertation demonstrates a real world application of a PEMFC hybrid electric vehicle. Through presenting the vehicle design concept, developing the real time control system and generating generic operation principles, this dissertation targets at establishing the public knowledge base on this new technology. A complete PEMFC hybrid electric vehicle design, including vehicle components layout, process flow diagram, real time control system architecture, subsystem structures and control algorithms, is presented in order to help understand the whole vehicle system. The design concept is validated through the vehicle demonstration. Generic operating principles are established along with the validation process, which helps populate this emerging technology. Thereafter, further improvements and future research directions are discussed.

  11. Critical Causes and Consequences of Construction Project Interruption: Client, Contractor, Consultant and External Factors Standpoints

    Directory of Open Access Journals (Sweden)

    Nurbasirah Mohamed Alias

    2013-09-01

    Full Text Available It should be pointed out that the dilemma of interruption and stoppage in the construction industry is a large-scale trend. Construction interruption and stoppage is considered one of the most recurring problems in the construction industry. Construction Interruption and stoppage is always measured as costly to all parties concerned in the projects and very often it will result in clash, claims, total desertion and much difficult for the feasibility and it slows the growth of construction sector. The objective of the research work that underpins this paper was to investigate the Factors and Consequences of construction projects on local contractors. A construction project is commonly acknowledged as successful when the aim of the project is achieved in terms of predetermined objectives that are mainly completed the project on time, within budget and specified quality in accordance with the specifications and to stakeholders’ satisfaction. One of the most important problems that may arise in the construction project is delays and the magnitude of these delays varies considerably from project to project. According to delay categories that were contractor related, client related, consultant related, labour related and external related, the study revealed the six major effects of delay that were time overrun, cost overrun, dispute, arbitration, total abandonment, and litigation.

  12. Basic interrupted versus continuous suturing techniques in bronchial anastomosis following sleeve lobectomy in dogs.

    Science.gov (United States)

    Bayram, Ahmet Sami; Erol, Mehmet Muharrem; Salci, Hakan; Ozyiğit, Ozgür; Görgül, Sacit; Gebitekin, Cengiz

    2007-12-01

    Sleeve resection with or without lung resection is a valid conservative operation for patients with benign or malignant tumors; it enables the preservation of lung parenchyma. The aim of this prospective randomized study was to compare complications, operating time, and bronchial healing between the techniques of interrupted and continuous suturing for bronchial anastomosis in dogs. Twenty adult mongrel dogs each weighing 18-22 kg (average: 20 kg) were divided into two groups according to the anastomosis technique performed: group A, interrupted suturing and group B, continuous suturing. Each group comprised of 10 dogs. Following right thoracotomy, sleeve resection of the right cranial lobe was performed in all dogs. Basic interrupted sutures using 4/0 Vicryl (Ethicon, USA) were used in group A, and continuous sutures were used in group B. The median anastomosis time was 15.2 min (range: 13-21 min) in group A and 9.6 min (range: 8-13 min) in group B. In all dogs, the anastomosis line was resected via right pneumonectomy for histopathological investigation 1 month after sleeve resection. Histopathological examination revealed that the healing of the anastomosis was not affected by the suturing technique applied. One dog from each group died on the fourth postoperative day; Fisher's exact test, p=0.763. Our research revealed that the healing of the anastomosis was not affected by the suturing technique performed.

  13. Efficient Evaluation of Wireless Real-Time Control Networks

    Directory of Open Access Journals (Sweden)

    Peter Horvath

    2015-02-01

    Full Text Available In this paper, we present a system simulation framework for the design and performance evaluation of complex wireless cyber-physical systems. We describe the simulator architecture and the specific developments that are required to simulate cyber-physical systems relying on multi-channel, multihop mesh networks. We introduce realistic and efficient physical layer models and a system simulation methodology, which provides statistically significant performance evaluation results with low computational complexity. The capabilities of the proposed framework are illustrated in the example of WirelessHART, a centralized, real-time, multi-hop mesh network designed for industrial control and monitor applications.

  14. Real time modeling, simulation and control of dynamical systems

    CERN Document Server

    Mughal, Asif Mahmood

    2016-01-01

    This book introduces modeling and simulation of linear time invariant systems and demonstrates how these translate to systems engineering, mechatronics engineering, and biomedical engineering. It is organized into nine chapters that follow the lectures used for a one-semester course on this topic, making it appropriate for students as well as researchers. The author discusses state space modeling derived from two modeling techniques and the analysis of the system and usage of modeling in control systems design. It also contains a unique chapter on multidisciplinary energy systems with a special focus on bioengineering systems and expands upon how the bond graph augments research in biomedical and bio-mechatronics systems.

  15. Managing time-substitutable electricity usage using dynamic controls

    Science.gov (United States)

    Ghosh, Soumyadip; Hosking, Jonathan R.; Natarajan, Ramesh; Subramaniam, Shivaram; Zhang, Xiaoxuan

    2017-02-21

    A predictive-control approach allows an electricity provider to monitor and proactively manage peak and off-peak residential intra-day electricity usage in an emerging smart energy grid using time-dependent dynamic pricing incentives. The daily load is modeled as time-shifted, but cost-differentiated and substitutable, copies of the continuously-consumed electricity resource, and a consumer-choice prediction model is constructed to forecast the corresponding intra-day shares of total daily load according to this model. This is embedded within an optimization framework for managing the daily electricity usage. A series of transformations are employed, including the reformulation-linearization technique (RLT) to obtain a Mixed-Integer Programming (MIP) model representation of the resulting nonlinear optimization problem. In addition, various regulatory and pricing constraints are incorporated in conjunction with the specified profit and capacity utilization objectives.

  16. Managing time-substitutable electricity usage using dynamic controls

    Science.gov (United States)

    Ghosh, Soumyadip; Hosking, Jonathan R.; Natarajan, Ramesh; Subramaniam, Shivaram; Zhang, Xiaoxuan

    2017-02-07

    A predictive-control approach allows an electricity provider to monitor and proactively manage peak and off-peak residential intra-day electricity usage in an emerging smart energy grid using time-dependent dynamic pricing incentives. The daily load is modeled as time-shifted, but cost-differentiated and substitutable, copies of the continuously-consumed electricity resource, and a consumer-choice prediction model is constructed to forecast the corresponding intra-day shares of total daily load according to this model. This is embedded within an optimization framework for managing the daily electricity usage. A series of transformations are employed, including the reformulation-linearization technique (RLT) to obtain a Mixed-Integer Programming (MIP) model representation of the resulting nonlinear optimization problem. In addition, various regulatory and pricing constraints are incorporated in conjunction with the specified profit and capacity utilization objectives.

  17. Real Time Implementation of a DC Motor Speed Control by Fuzzy Logic Controller and PI Controller Using FPGA

    Directory of Open Access Journals (Sweden)

    G. Sakthivel

    2010-10-01

    Full Text Available Fuzzy logic control has met with growing interest in many motor control applications due to its non-linearity, handling features and independence of plant modelling. The hardware implementation of fuzzy logic controller (FLC on FPGA is very important because of the increasing number of fuzzy applications requiring highly parallel and high speed fuzzy processing. Implementation of a fuzzy logic controller and conventional PI controller on an FPGA using VHDL for DC motor speed control is presented in this paper. The proposed scheme is to improve tracking performance of D.C. motor as compared to the conventional (PI control strategy .This paper describes the hardware implementation of two inputs (error and change in error, one output fuzzy logic controller based on PI controller and conventional PI controller using VHDL. Real time implementation FLC and conventional PI controller is made on Spartan-3A DSP FPGA (XC3SD1800A FPGA for the speed control of DC motor. It is observed that fuzzy logic based controllers give better responses than the conventional PI controller for the speed control of dc motor.

  18. Nondestructive assay technology and automated ''real-time'' materials control

    International Nuclear Information System (INIS)

    Keepin, G.R.

    1977-01-01

    Significant advances in nondestructive assay techniques and instrumentation now enable rapid, accurate and direct in-plant measurement of nuclear material on a continuous or ''real-time'' basis as it progresses through a nuclear facility. A variety of passive and active assay instruments are required for the broad range of materials measurement problems encountered by safeguards inspectors and facility operators in various types of nuclear plants. Representative NDA techniques and instruments are presented and reviewed with special attention to their assay capabilities and areas of applicability in the nuclear fuel cycle. An advanced system of materials control - called ''DYMAC'', for Dynamic Materials Control - is presently under development by the U.S. Energy Research and Development Administration; the DYMAC program integrates new nondestructive assay instrumentation and modern data-processing methods, with the overall objective of demonstrating a workable, cost-effective system of stringent safeguards and materials control in various generic types of facilities found in the nuclear fuel cycle. Throughout the program, emphasis will be placed on devloping practical solutions to generic measurement problems so that resulting techniques and instrumentation will have widespread utility. Projected levels of safeguards assurance, together with other vital - and cost-sensitive - plant operational factors such as process and quality control, criticality safety and waste management are examined in an evaluation of the impact of future advanced materials control systems on overall plant operations, efficiency and productivity. The task of implementing effective and stringent safeguards includes the transfer of new safeguards technology to the nuclear industry. Clearly the training of inspectors (both IAEA and national), plant people, etc., in the effective use of new NDA equipment is of paramount importance; thus in the United States, the Energy Research and Development

  19. The Time Diagram Control Approach for the Dynamic Representation of Time-Oriented Data

    Directory of Open Access Journals (Sweden)

    Rolf Dornberger

    2016-04-01

    Full Text Available The dynamic representation of time-oriented data on small screen devices is of increasing importance. Most solution approaches use issue-specific requirements based on established desktop technologies. Applied to mobile devices with small multi-touch displays such approaches often lead to a limited usability. Particularly, the time-dependent data can only be fragmentarily visualized due to limited screen sizes. Instead of reducing the complexity by visualizing the data, the interpretation of the data is getting more complex. This paper proposes a Time Diagram Control (TDC approach, a new way of representing time-based diagrams on small screen devices. The TDC uses a principle of cybernetics to integrate the user in the visualization process and thus reduce complexity. TDC focuses on simplicity of design by only providing 2D temporal line diagrams with a dynamic zooming function that works via standard multi-touch controls. Involving the user into a continuous loop of refining the visualization, TDC allows to compare data of different temporal granularities without losing the overall context of the presented data. The TDC approach ensures constant information reliability on small screen devices.

  20. Controlling chaos in a nonlinear pendulum using an extended time-delayed feedback control method

    International Nuclear Information System (INIS)

    Souza de Paula, Aline; Savi, Marcelo Amorim

    2009-01-01

    Chaos control is employed for the stabilization of unstable periodic orbits (UPOs) embedded in chaotic attractors. The extended time-delayed feedback control uses a continuous feedback loop incorporating information from previous states of the system in order to stabilize unstable orbits. This article deals with the chaos control of a nonlinear pendulum employing the extended time-delayed feedback control method. The control law leads to delay-differential equations (DDEs) that contain derivatives that depend on the solution of previous time instants. A fourth-order Runge-Kutta method with linear interpolation on the delayed variables is employed for numerical simulations of the DDEs and its initial function is estimated by a Taylor series expansion. During the learning stage, the UPOs are identified by the close-return method and control parameters are chosen for each desired UPO by defining situations where the largest Lyapunov exponent becomes negative. Analyses of a nonlinear pendulum are carried out by considering signals that are generated by numerical integration of the mathematical model using experimentally identified parameters. Results show the capability of the control procedure to stabilize UPOs of the dynamical system, highlighting some difficulties to achieve the stabilization of the desired orbit.