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Sample records for random interval schedules

  1. Pigeons' Choices between Fixed-Interval and Random-Interval Schedules: Utility of Variability?

    ERIC Educational Resources Information Center

    Andrzejewski, Matthew E.; Cardinal, Claudia D.; Field, Douglas P.; Flannery, Barbara A.; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N.

    2005-01-01

    Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the…

  2. The Probability of Small Schedule Values and Preference for Random-Interval Schedules

    ERIC Educational Resources Information Center

    Soreth, Michelle Ennis; Hineline, Philip N.

    2009-01-01

    Preference for working on variable schedules and temporal discrimination were simultaneously examined in two experiments using a discrete-trial, concurrent-chains arrangement with fixed interval (FI) and random interval (RI) terminal links. The random schedule was generated by first sampling a probability distribution after the programmed delay to…

  3. Pigeons' choices between fixed-interval and random-interval schedules: utility of variability?

    PubMed

    Andrzejewski, Matthew E; Cardinal, Claudia D; Field, Douglas P; Flannery, Barbara A; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N

    2005-03-01

    Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the fixed-interval schedule. Thus the programmed delays to reinforcement on the random alternative were never shorter and were often longer than the fixed interval. Despite this feature, the fixed schedule was not strongly preferred. Increases in the probability used to generate the random interval resulted in decreased preferences for the fixed schedule. In addition, the number of consecutive choices on the preferred alternative varied directly with preference, whereas the consecutive number of choices on the nonpreferred alternative was fairly constant. The probability of choosing the random alternative was unaffected by the immediately prior interval encountered on that schedule, even when it was very long relative to the average value. The results loosely support conceptions of a "preference for variability" from foraging theory and the "utility of behavioral variability" from human decision-making literatures. PMID:15828591

  4. Strict and random alternation in concurrent variable-interval schedules.

    PubMed Central

    Elliffe, Douglas; Davison, Michael

    2003-01-01

    Six pigeons responded on pairs of concurrent variable-interval schedules with, in different parts, four different arrangements of alternation between schedules. Following a single switching-key response, alternation was either strict or random, and the alternative presented after a switch (the postswitch alternative) was either signaled by the location of the switching key or unsignaled. Generalized-matching analyses showed little difference in behavior among the different alternation arrangements, except the usual finding of lower sensitivity of response allocation than time allocation was eliminated by arranging random alternation. Patterns of interchangeover times were similar for all arrangements except signaled random alternation. Differences in behavior preceding the different postswitch alternatives were found in the signaled random alternation procedure. Preference was biased towards the color of the signaled postswitch alternative and showed increased sensitivity when the postswitch alternative was to be the one with the higher reinforcer rate. Interchangeover times were substantially shorter when the postswitch alternative was signaled to be different from the current alternative than when it was signaled to be the same. However, when separate reinforcer ratios were calculated for the different postswitch alternatives, those effects were eliminated or greatly reduced. We suggest that, although behavior is indeed influenced by the postswitch alternative, the mechanism is indirect. That is, the distributions of reinforcers between alternatives obtained before each postswitch alternative differ when those alternatives are signaled, and those distributions are discriminated, but the same relations between choice and relative reinforcement hold irrespective of which postswitch alternative is signaled. PMID:12696742

  5. Relationship between Contingency Awareness and Human Performance on Random Ratio and Random Interval Schedules

    ERIC Educational Resources Information Center

    Bradshaw, Ceri A.; Reed, Phil

    2012-01-01

    In three experiments, human participants pressed the space bar on a computer keyboard to earn points on random-ratio (RR) and random-interval (RI) schedules of reinforcement. Verbalized contingency awareness (CA) for each schedule was measured after the entire task (Experiments 1 and 2), or after each RR-RI trial (Experiment 3). In all three…

  6. The Probability of Small Schedule Values and Preference for Random-Interval Schedules

    PubMed Central

    Soreth, Michelle Ennis; Hineline, Philip N

    2009-01-01

    Preference for working on variable schedules and temporal discrimination were simultaneously examined in two experiments using a discrete-trial, concurrent-chains arrangement with fixed interval (FI) and random interval (RI) terminal links. The random schedule was generated by first sampling a probability distribution after the programmed delay to reinforcement on the FI schedule had elapsed, and thus the RI never produced a component schedule value shorter than the FI and maintained a rate of reinforcement half that of the FI. Despite these features, the FI was not strongly preferred. The probability of obtaining the smallest programmed delay to reinforcement on the RI schedule was manipulated in Experiment 1, and the interaction of this probability and initial link length was examined in Experiment 2. As the probability of obtaining small values in the RI increased, preference for the schedule increased while the discriminated time of reinforcer availability in the terminal link decreased. Both of these effects were attenuated by lengthening the initial links. The results support the view that in addition to the delay to reinforcement, the probability of obtaining a short delay is an important choice-affecting variable that likely contributes to the robust preferences for variable, as opposed to fixed, schedules of reinforcement. PMID:19230514

  7. Rats show molar sensitivity to different aspects of random-interval-with-linear-feedback-functions and random-ratio schedules.

    PubMed

    Reed, Phil

    2015-10-01

    Three experiments examined the impact of various aspects of reinforcement contingencies on responding maintained by free-operant schedules by food-deprived rats. Experiment 1 demonstrated that random interval (RI) and random-interval-with-positive-response-reinforcer-feedback (RI+) schedules maintained similar rates of responding at a variety of reinforcer frequencies. Experiment 2 demonstrated that a random ratio (RR) schedule maintained higher rates than RI or RI+ schedules, except at high rates of reinforcement, where response rates were similar on all schedules. Experiment 3 again demonstrated that RR schedules produced higher response rates than either RI or RI+ schedules, but modification of the RI+ schedule to prevent ratio strain enhanced response rates relative to an RI schedule. Together these results reveal a pattern of interacting factors in schedule controlled behavior: at high rates of reinforcement, this factor overrides the impact of other controlling factors, but as reinforcement rate decreases the joint impact of interresponse times reinforcement, response-reinforcer feedback functions, and ratio strain are observed. PMID:25915752

  8. Sensory superstition on multiple interval schedules.

    PubMed

    Starr, B C; Staddon, J E

    1982-03-01

    Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food. PMID:7069361

  9. Sensory superstition on multiple interval schedules.

    PubMed Central

    Starr, B C; Staddon, J E

    1982-01-01

    Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food. PMID:7069361

  10. Optimal randomized scheduling by replacement

    SciTech Connect

    Saias, I.

    1996-05-01

    In the replacement scheduling problem, a system is composed of n processors drawn from a pool of p. The processors can become faulty while in operation and faulty processors never recover. A report is issued whenever a fault occurs. This report states only the existence of a fault but does not indicate its location. Based on this report, the scheduler can reconfigure the system and choose another set of n processors. The system operates satisfactorily as long as, upon report of a fault, the scheduler chooses n non-faulty processors. We provide a randomized protocol maximizing the expected number of faults the system can sustain before the occurrence of a crash. The optimality of the protocol is established by considering a closely related dual optimization problem. The game-theoretic technical difficulties that we solve in this paper are very general and encountered whenever proving the optimality of a randomized algorithm in parallel and distributed computation.

  11. Interval-valued random functions and the kriging of intervals

    SciTech Connect

    Diamond, P.

    1988-04-01

    Estimation procedures using data that include some values known to lie within certain intervals are usually regarded as problems of constrained optimization. A different approach is used here. Intervals are treated as elements of a positive cone, obeying the arithmetic of interval analysis, and positive interval-valued random functions are discussed. A kriging formalism for interval-valued data is developed. It provides estimates that are themselves intervals. In this context, the condition that kriging weights be positive is seen to arise in a natural way. A numerical example is given, and the extension to universal kriging is sketched.

  12. Variable-ratio versus variable-interval schedules: response rate, resistance to change, and preference.

    PubMed Central

    Nevin, J A; Randolph; Holland, S; McLean, A P

    2001-01-01

    Two experiments asked whether resistance to change depended on variable-ratio as opposed to variable-interval contingencies of reinforcement and the different response rates they establish. In Experiment 1, pigeons were trained on multiple random-ratio random-interval schedules with equated reinforcer rates. Baseline response rates were disrupted by intercomponent food, extinction, and prefeeding. Resistance to change relative to baseline was greater in the interval component, and the difference was correlated with the extent to which baseline response rates were higher in the ratio component. In Experiment 2, pigeons were trained on multiple variable-ratio variable-interval schedules in one half of each session and on concurrent chains in the other half in which the terminal links corresponded to the multiple-schedule components. The schedules were varied over six conditions, including two with equated reinforcer rates. In concurrent chains, preference strongly overmatched the ratio of obtained reinforcer rates. In multiple schedules, relative resistance to response-independent food during intercomponent intervals, extinction, and intercomponent food plus extinction depended on the ratio of obtained reinforcer rates but was less sensitive than was preference. When reinforcer rates were similar, both preference and relative resistance were greater for the variable-interval schedule, and the differences were correlated with the extent to which baseline response rates were higher on the variable-ratio schedule, confirming the results of Experiment 1. These results demonstrate that resistance to change and preference depend in part on response rate as well as obtained reinforcer rate, and challenge the independence of resistance to change and preference with respect to response rate proposed by behavioral momentum theory. PMID:11516115

  13. Generating Variable and Random Schedules of Reinforcement Using Microsoft Excel Macros

    ERIC Educational Resources Information Center

    Bancroft, Stacie L.; Bourret, Jason C.

    2008-01-01

    Variable reinforcement schedules are used to arrange the availability of reinforcement following varying response ratios or intervals of time. Random reinforcement schedules are subtypes of variable reinforcement schedules that can be used to arrange the availability of reinforcement at a constant probability across number of responses or time.…

  14. Drug discrimination under two concurrent fixed-interval fixed-interval schedules.

    PubMed Central

    McMillan, D E; Li, M

    2000-01-01

    Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a two-key concurrent fixed-interval (FI) 100-s FI 200-s schedule of food presentation, and later tinder a concurrent FI 40-s FI 80-s schedule, in which the FI component with the shorter time requirement reinforced responding on one key after drug administration (pentobarbital-biased key) and on the other key after saline administration (saline-biased key). After responding stabilized under the concurrent FI 100-s FI 200-s schedule, pigeons earned an average of 66% (after pentobarbital) to 68% (after saline) of their reinforcers for responding under the FI 100-s component of the concurrent schedule. These birds made an average of 70% of their responses on both the pentobarbital-biased key after the training dose of pentobarbital and the saline-biased key after saline. After responding stabilized under the concurrent FI 40-s FI 80-s schedule, pigeons earned an average of 67% of their reinforcers for responding under the FI 40 component after both saline and the training dose of pentobarbital. These birds made an average of 75% of their responses on the pentobarbital-biased key after the training dose of pentobarbital, but only 55% of their responses on the saline-biased key after saline. In test sessions preceded by doses of pentobarbital, chlordiazepoxide, ethanol, phencyclidine, or methamphetamine, the dose-response curves were similar under these two concurrent schedules. Pentobarbital, chlordiazepoxide, and ethanol produced dose-dependent increases in responding on the pentobarbital-biased key as the doses increased. For some birds, at the highest doses of these drugs, the dose-response curve turned over. Increasing doses of phencyclidine produced increased responding on the pentobarbital-biased key in some, but not all, birds. After methamphetamine, responding was largely confined to the saline-biased key. These data show that pigeons can perform drug discriminations under concurrent

  15. Drug discrimination under two concurrent fixed-interval fixed-interval schedules.

    PubMed

    McMillan, D E; Li, M

    2000-07-01

    Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a two-key concurrent fixed-interval (FI) 100-s FI 200-s schedule of food presentation, and later tinder a concurrent FI 40-s FI 80-s schedule, in which the FI component with the shorter time requirement reinforced responding on one key after drug administration (pentobarbital-biased key) and on the other key after saline administration (saline-biased key). After responding stabilized under the concurrent FI 100-s FI 200-s schedule, pigeons earned an average of 66% (after pentobarbital) to 68% (after saline) of their reinforcers for responding under the FI 100-s component of the concurrent schedule. These birds made an average of 70% of their responses on both the pentobarbital-biased key after the training dose of pentobarbital and the saline-biased key after saline. After responding stabilized under the concurrent FI 40-s FI 80-s schedule, pigeons earned an average of 67% of their reinforcers for responding under the FI 40 component after both saline and the training dose of pentobarbital. These birds made an average of 75% of their responses on the pentobarbital-biased key after the training dose of pentobarbital, but only 55% of their responses on the saline-biased key after saline. In test sessions preceded by doses of pentobarbital, chlordiazepoxide, ethanol, phencyclidine, or methamphetamine, the dose-response curves were similar under these two concurrent schedules. Pentobarbital, chlordiazepoxide, and ethanol produced dose-dependent increases in responding on the pentobarbital-biased key as the doses increased. For some birds, at the highest doses of these drugs, the dose-response curve turned over. Increasing doses of phencyclidine produced increased responding on the pentobarbital-biased key in some, but not all, birds. After methamphetamine, responding was largely confined to the saline-biased key. These data show that pigeons can perform drug discriminations under concurrent

  16. Drug discrimination under a concurrent fixed-interval fixed-interval schedule.

    PubMed Central

    McMillan, D E; Li, M; Hardwick, W C

    1997-01-01

    Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a concurrent fixed-interval (FI) FI schedule of food presentation on which, after pentobarbital administration, responses on one key were reinforced with food under an FI 60-s component and responses on the other key were reinforced under an FI 240-s component. After saline administration, the schedule contingencies on the two keys were reversed. After both pentobarbital and saline, pigeons responded more frequently on the key on which responses had been programmed to produce the reinforcer under the FI 60 component of the concurrent schedule. The schedule was changed to concurrent FI 150 FI 150 s for drug-substitution tests. In each bird, increasing doses of pentobarbital, ethanol, and chlordiazepoxide produced increases in the proportion of responses on the key on which responses had been reinforced under the FI 60 component after pentobarbital administration during training sessions. The proportion of responses on that key was slightly lower for ethanol than for chlordiazepoxide and pentobarbital. At a dose of pentobarbital higher than the training dose, responding decreased on the key that had been reinforced under the FI 60 component during training sessions. Phencyclidine produced less responding on the key programmed under the FI 60-s component than did pentobarbital. Methamphetamine produced responding primarily on the key on which responses had been reinforced under the FI 60-s component after saline administration. PMID:9335138

  17. Drug discrimination in rats under concurrent variable-interval variable-interval schedules.

    PubMed Central

    McMillan, D E; Hardwick, W C

    2000-01-01

    Eight rats were trained to discriminate pentobarbital from saline under a concurrent variable-interval (VI) VI schedule, on which responses on the pentobarbital-biased lever after pentobarbital were reinforced under VI 20 s and responses on the saline-biased lever were reinforced under VI 80 s. After saline, the reinforcement contingencies programmed on the two levers were reversed. The rats made 62.3% of their responses on the pentobarbital-biased lever after pentobarbital and 72.2% on the saline-biased lever after saline, both of which are lower than predicted by the matching law. When the schedule was changed to concurrent VI 50 s VI 50 s for test sessions with saline and the training dose of pentobarbital, responding on the pentobarbital-biased lever after the training dose of pentobarbital and on the saline-biased lever after saline became nearly equal, even during the first 2 min of the session, suggesting that the presence or absence of the training drug was exerting minimal control over responding and making the determination of dose-effect relations of drugs difficult to interpret. When the pentobarbital dose-response curve was determined under the concurrent VI 50-s VI 50-s schedule, responding was fairly evenly distributed on both levers for most rats. Therefore, 6 additional rats were trained to respond under a concurrent VI 60-s VI 240-s schedule. Under this schedule, the rats made 62.6% of their responses on the pentobarbital-biased lever after pentobarbital and 73.5% of their responses on the saline-biased lever after saline, which also is lower than the percentages predicted by perfect matching. When the schedule was changed to a concurrent VI 150-s VI 150-s schedule for 5-min test sessions with additional drugs, the presence or absence of pentobarbital continued to control responding in most rats, and it was possible to generate graded dose-response curves for pentobarbital and other drugs using the data from these 5-min sessions. The dose

  18. Interresponse Time Structures in Variable-Ratio and Variable-Interval Schedules

    ERIC Educational Resources Information Center

    Bowers, Matthew T.; Hill, Jade; Palya, William L.

    2008-01-01

    The interresponse-time structures of pigeon key pecking were examined under variable-ratio, variable-interval, and variable-interval plus linear feedback schedules. Whereas the variable-ratio and variable-interval plus linear feedback schedules generally resulted in a distinct group of short interresponse times and a broad distribution of longer…

  19. Determinants of Human Fixed-Interval Performance Following Varied Exposure to Reinforcement Schedules

    ERIC Educational Resources Information Center

    Torgrud, Laine J.; Holborn, Stephen W.; Zak, Robert D.

    2006-01-01

    Undergraduates given accurate instructions pressed keys for token points under either a variety of reinforcement schedules (variety training) or under a single schedule. Response rates on a fixed-interval (FI) test schedule then were assessed. Experiment 1 compared variety training inclusive of FI-optimal rates (functional) to training excluding…

  20. Contracting, equal, and expanding learning schedules: the optimal distribution of learning sessions depends on retention interval.

    PubMed

    Küpper-Tetzel, Carolina E; Kapler, Irina V; Wiseheart, Melody

    2014-07-01

    In laboratory and applied learning experiments, researchers have extensively investigated the optimal distribution of two learning sessions (i.e., initial learning and one relearning session) for the learning of verbatim materials. However, research has not yet provided a satisfying and conclusive answer to the optimal scheduling of three learning sessions (i.e., initial learning and two relearning sessions) across educationally relevant time intervals. Should the to-be-learned material be repeated at decreasing intervals (contracting schedule), constant intervals (equal schedule), or increasing intervals (expanding schedule) between learning sessions? Different theories and memory models (e.g., study-phase retrieval theory, contextual variability theory, ACT-R, and the Multiscale Context Model) make distinct predictions about the optimal learning schedule. We discuss the extant theories and derive clear predictions from each of them. To test these predictions empirically, we conducted an experiment in which participants studied and restudied paired associates with a contracting, equal, or expanding learning schedule. Memory performance was assessed immediately, 1 day, 7 days, or 35 days later with free- and cued-recall tests. Our results revealed that the optimal learning schedule is conditional on the length of the retention interval: A contracting learning schedule was beneficial for retention intervals up to 7 days, but both equal and expanding learning schedules were better for a long retention interval of 35 days. Our findings can be accommodated best by the contextual variability theory and indicate that revisions are needed to existing memory models. Our results are practically relevant, and their implications for real-world learning are discussed. PMID:24500777

  1. Bouts of Responding on Variable-Interval Schedules: Effects of Deprivation Level

    ERIC Educational Resources Information Center

    Shull, Richard L.

    2004-01-01

    Rats obtained food pellets on a variable-interval schedule of reinforcement by nose poking a lighted key. After training to establish baseline performance (with the mean variable interval set at either 60, 120, or 240 s), the rats were given free access to food during the hour just before their daily session. This satiation operation reduced the…

  2. Bouts of responding on variable-interval schedules: effects of deprivation level.

    PubMed Central

    Shull, Richard L

    2004-01-01

    Rats obtained food pellets on a variable-interval schedule of reinforcement by nose poking a lighted key. After training to establish baseline performance (with the mean variable interval set at either 60, 120, or 240 s), the rats were given free access to food during the hour just before their daily session. This satiation operation reduced the rate of key poking. Analysis of the interresponse time distributions (log survivor plots) indicated that key poking occurred in bouts. Prefeeding lengthened the pauses between bouts, shortened the length of bouts (less reliably), and had a relatively small decremental effect on the response rate within bouts. That deprivation level affects mainly between-bout pauses has been reported previously with fixed-ratio schedules. Thus, when the focus is on bouts, the performances maintained by variable-interval schedules and fixed-ratio schedules are similarly affected by deprivation. PMID:15239490

  3. Interval process model and non-random vibration analysis

    NASA Astrophysics Data System (ADS)

    Jiang, C.; Ni, B. Y.; Liu, N. Y.; Han, X.; Liu, J.

    2016-07-01

    This paper develops an interval process model for time-varying or dynamic uncertainty analysis when information of the uncertain parameter is inadequate. By using the interval process model to describe a time-varying uncertain parameter, only its upper and lower bounds are required at each time point rather than its precise probability distribution, which is quite different from the traditional stochastic process model. A correlation function is defined for quantification of correlation between the uncertain-but-bounded variables at different times, and a matrix-decomposition-based method is presented to transform the original dependent interval process into an independent one for convenience of subsequent uncertainty analysis. More importantly, based on the interval process model, a non-random vibration analysis method is proposed for response computation of structures subjected to time-varying uncertain external excitations or loads. The structural dynamic responses thus can be derived in the form of upper and lower bounds, providing an important guidance for practical safety analysis and reliability design of structures. Finally, two numerical examples and one engineering application are investigated to demonstrate the feasibility of the interval process model and corresponding non-random vibration analysis method.

  4. PREDICTION INTERVALS FOR INTEGRALS OF GAUSSIAN RANDOM FIELDS.

    PubMed

    De Oliveira, Victor; Kone, Bazoumana

    2015-03-01

    Methodology is proposed for the construction of prediction intervals for integrals of Gaussian random fields over bounded regions (called block averages in the geostatistical literature) based on observations at a finite set of sampling locations. Two bootstrap calibration algorithms are proposed, termed indirect and direct, aimed at improving upon plug-in prediction intervals in terms of coverage probability. A simulation study is carried out that illustrates the effectiveness of both procedures, and these procedures are applied to estimate block averages of chromium traces in a potentially contaminated region in Switzerland. PMID:25431507

  5. PREDICTION INTERVALS FOR INTEGRALS OF GAUSSIAN RANDOM FIELDS

    PubMed Central

    De Oliveira, Victor; Kone, Bazoumana

    2014-01-01

    Methodology is proposed for the construction of prediction intervals for integrals of Gaussian random fields over bounded regions (called block averages in the geostatistical literature) based on observations at a finite set of sampling locations. Two bootstrap calibration algorithms are proposed, termed indirect and direct, aimed at improving upon plug-in prediction intervals in terms of coverage probability. A simulation study is carried out that illustrates the effectiveness of both procedures, and these procedures are applied to estimate block averages of chromium traces in a potentially contaminated region in Switzerland. PMID:25431507

  6. An Efficient Uplink Scheduling Algorithm with Variable Grant-Interval for VoIP Service in BWA Systems

    NASA Astrophysics Data System (ADS)

    Oh, Sung-Min; Cho, Sunghyun; Kim, Jae-Hyun; Kwun, Jonghyung

    This letter proposes an efficient uplink scheduling algorithm for the voice over Internet protocol (VoIP) service with variable frame-duration according to the voice activity in IEEE 802.16e/m systems. The proposed algorithm dynamically changes the grant-interval to save the uplink bandwidth, and it uses the random access scheme when the voice activity changes from silent-period to talk-spurt. Numerical results show that the proposed algorithm can increase the VoIP capacity by 26 percent compared to the conventional extended real-time polling service (ertPS).

  7. Performance under Competitive and Self-Competitive Fixed-Interval Schedules of Reinforcement

    ERIC Educational Resources Information Center

    Saville, Bryan K.

    2009-01-01

    Participants completed blocks of trials under simple (i.e., work-alone), competitive, and self-competitive fixed-interval 20-s schedules of reinforcement. In general, response rates were highest during competition and lowest while working alone. In addition, whereas participants emitted responses at a constant rate while working alone, competitive…

  8. Responding maintained by the opportunity to attack during an interval food reinforcement schedule1

    PubMed Central

    Cherek, D. R.; Thompson, T.; Heistad, G. T.

    1973-01-01

    Pigeons responded in a two-key situation. Responses on the right key (food key) were reinforced with food presentation on a response-initiated fixed-interval schedule, (i.e., first response after a fixed period of time was reinforced); responses on the left key (target key) were reinforced on a fixed-ratio schedule (i.e., every nth response was reinforced) with the presentation of a target bird that could be attacked. When the interval value of the food reinforcement schedule was varied from 1 min to 5 min, both the rate of attack responding on the target bird and the rate of responding on the target key were a function of the interval value. Responding on the target key was not maintained by the stimulus change associated with target availability, and was successively extinguished and reconditioned by removing and returning the target bird to the restraining box. When food was delivered independently of behavior, responding on the target key either remained unchanged or decreased, but was not eliminated. Responding on the target key was not maintained in the absence of an intermittent schedule of food presentation. PMID:4735893

  9. Effects of On-Demand Versus Fixed-Interval Schedules in the Treatment of Chronic Pain With Analgesic Compounds.

    ERIC Educational Resources Information Center

    Berntzen, Dagfinn; Gotestam, K. Gunnar

    1987-01-01

    Compared the effects of fixed-interval and on-demand administration of analgesic medications in chronic pain patients. A fixed-interval analgesic schedule was found more effective than an on-demand schedule in reducing subjective pain and elevating mood. No differences were found between the two conditions on measures of physical activity.…

  10. On the Primacy of Molecular Processes in Determining Response Rates under Variable-Ratio and Variable-Interval Schedules

    ERIC Educational Resources Information Center

    Tanno, Takayuki; Sakagami, Takayuki

    2008-01-01

    This study focused on variables that may account for response-rate differences under variable-ratio (VR) and variable-interval (VI) schedules of reinforcement. Four rats were exposed to VR, VI, tandem VI differential- reinforcement-of-high-rate, regulated-probability-interval, and negative-feedback schedules of reinforcement that provided the same…

  11. Information Processing with Length Intervals of Stationary Random Point Processes

    NASA Astrophysics Data System (ADS)

    Bendjaballah, Cherif

    2011-04-01

    For some typical noiseless binary channels operating with signals at low power level, the limits of the information transmission are computed. This is performed for random point processes on a subset of size and on the semi line . The calculations are compared using two length intervals processors, depending on whether the processor starts with a point of the process (type I processor) or with an arbitrary point (type II processor).

  12. Calculation of Flight Deck Interval Management Assigned Spacing Goals Subject to Multiple Scheduling Constraints

    NASA Technical Reports Server (NTRS)

    Robinson, John E.

    2014-01-01

    The Federal Aviation Administration's Next Generation Air Transportation System will combine advanced air traffic management technologies, performance-based procedures, and state-of-the-art avionics to maintain efficient operations throughout the entire arrival phase of flight. Flight deck Interval Management (FIM) operations are expected to use sophisticated airborne spacing capabilities to meet precise in-trail spacing from top-of-descent to touchdown. Recent human-in-the-loop simulations by the National Aeronautics and Space Administration have found that selection of the assigned spacing goal using the runway schedule can lead to premature interruptions of the FIM operation during periods of high traffic demand. This study compares three methods for calculating the assigned spacing goal for a FIM operation that is also subject to time-based metering constraints. The particular paradigms investigated include: one based upon the desired runway spacing interval, one based upon the desired meter fix spacing interval, and a composite method that combines both intervals. These three paradigms are evaluated for the primary arrival procedures to Phoenix Sky Harbor International Airport using the entire set of Rapid Update Cycle wind forecasts from 2011. For typical meter fix and runway spacing intervals, the runway- and meter fix-based paradigms exhibit moderate FIM interruption rates due to their inability to consider multiple metering constraints. The addition of larger separation buffers decreases the FIM interruption rate but also significantly reduces the achievable runway throughput. The composite paradigm causes no FIM interruptions, and maintains higher runway throughput more often than the other paradigms. A key implication of the results with respect to time-based metering is that FIM operations using a single assigned spacing goal will not allow reduction of the arrival schedule's excess spacing buffer. Alternative solutions for conducting the FIM operation

  13. Clock control of human performance on avoidance and fixed-interval schedules1

    PubMed Central

    Baron, Alan; Galizio, Mark

    1976-01-01

    The avoidance and fixed-interval performances of human subjects were studied in two experiments. Addition of time-correlated stimuli (added clock) improved behavioral efficiency, since response rates decreased without decreases in reinforcement rates. Response-dependent display of the clock maintained a second, observing response and reductions in clock duration weakened such observing behavior. Generally, the reinforcing properties of the clock were more apparent with the avoidance than with the fixed-interval schedule, a finding attributed to temporal cues already provided by delivery of the fixed-interval reinforcers. Reduced rates of the main response when the clock was dependent on an observing response were more than offset by rates of the observing response in the majority of subjects. Thus, the results do not support an interpretation of the reinforcing properties of added clocks simply in terms of work reduction. PMID:16811938

  14. Pigeons' choices with token stimuli in concurrent variable-interval schedules.

    PubMed

    Mazur, James E; Biondi, Dawn R

    2013-03-01

    Twelve pigeons responded on concurrent variable-interval schedules that delivered token stimuli (stimulus lights for some pigeons, and white circles on the response keys for others). During exchange periods, each token could be exchanged for food on a fixed-ratio 1 schedule. Across conditions, the exchange requirements (number of tokens that had to be earned before they could be exchanged for food) varied between one and four for the two response keys. The main findings were that the pigeons' response percentages varied as a function of the number of tokens earned at any given moment, and they were determined by both the delays to food and by the number of food deliveries in the exchange periods. In some conditions, tokens had to be earned but were not visible during the variable-interval schedules for one or both keys. When one key had visible tokens and the other did not, the pigeons showed a preference for the key without visible tokens. A model based on the matching law and a hyperbolic delay-discounting equation could account for the main patterns of choice responding, and for how response percentages changed as successive tokens were earned. The results are consistent with the view that the token stimuli served as discriminative stimuli that signaled the current delays to food. PMID:23460072

  15. Neurochemical changes correlated with behavior maintained under fixed-interval and fixed-ratio schedules of reinforcement.

    PubMed Central

    Barrett, J E; Hoffmann, S M

    1991-01-01

    Key pecking of 4 pigeons was maintained under a multiple 3-min fixed-interval, 30-response fixed-ratio schedule of food presentation. Only one schedule was in effect during an experimental session, and each was correlated with a different keylight stimulus and location (left vs. right). The different schedule components alternated across days or weeks. Cerebrospinal fluid was collected from chronically implanted intracerebroventricular cannulae following sessions with the different schedules, as well as following sessions in which reinforcement was withheld (extinction), when response-independent food was delivered, and when the experimental chamber was dark and there were no scheduled events. Metabolites of the neurotransmitters serotonin, norepinephrine, and dopamine were assayed in cerebrospinal fluid using high-performance liquid chromatography with electrochemical detection. Compared to the fixed-ratio condition, responding maintained under the fixed-interval schedule resulted in consistently higher levels of the serotonin metabolite 5-hydroxyindoleacetic acid and of the dopamine metabolite homovanillic acid in all pigeons. Levels of 3-methoxy-4-hydroxyphenylethylene glycol, a metabolite of norepinephrine, and dihydroxyphenylacetic acid, another dopamine metabolite, were also higher in 3 of the 4 pigeons following exposure to the fixed-interval schedules when compared to levels of these metabolites after exposure to the fixed-ratio schedule. Extinction of fixed-ratio responding resulted in large increases in 5-hydroxyindoleacetic acid compared to levels of this metabolite under the fixed-ratio schedule, whereas this serotonin metabolite decreased during extinction of responding under the fixed-interval schedule. Control procedures suggested that the neurochemical changes were not related to the rate of responding but were a function of the specific experimental conditions. Distinctive neurochemical changes that accompany schedule-controlled responding show the

  16. Development of Key-Pecking, Pause, and Ambulation during Extended Exposure to a Fixed-Interval Schedule of Reinforcement

    ERIC Educational Resources Information Center

    Berry, Meredith S.; Kangas, Brian D.; Branch, Marc N.

    2012-01-01

    Six pigeons key-pecked under a fixed-interval (FI) 3-min schedule of food presentation. Each pigeon was studied for 200 daily sessions with 15 intervals per session (3,000 total food presentations). Analyses included the examination of latency to first peck (pause), mean rate of key pecking, and ambulation. Characterizations of stable performance…

  17. Approximate representations of random intervals for hybrid uncertainty quantification in engineering modeling

    SciTech Connect

    Joslyn, C.

    2004-01-01

    We review our approach to the representation and propagation of hybrid uncertainties through high-complexity models, based on quantities known as random intervals. These structures have a variety of mathematical descriptions, for example as interval-valued random variables, statistical collections of intervals, or Dempster-Shafer bodies of evidence on the Borel field. But methods which provide simpler, albeit approximate, representations of random intervals are highly desirable, including p-boxes and traces. Each random interval, through its cumulative belief and plausibility measures functions, generates a unique p-box whose constituent CDFs are all of those consistent with the random interval. In turn, each p-box generates an equivalence class of random intervals consistent with it. Then, each p-box necessarily generates a unique trace which stands as the fuzzy set representation of the p-box or random interval. In turn each trace generates an equivalence class of p-boxes. The heart of our approach is to try to understand the tradeoffs between error and simplicity introduced when p-boxes or traces are used to stand in for various random interval operations. For example, Joslyn has argued that for elicitation and representation tasks, traces can be the most appropriate structure, and has proposed a method for the generation of canonical random intervals from elicited traces. But alternatively, models built as algebraic equations of uncertainty-valued variables (in our case, random-interval-valued) propagate uncertainty through convolution operations on basic algebraic expressions, and while convolution operations are defined on all three structures, we have observed that the results of only some of these operations are preserved as one moves through these three levels of specificity. We report on the status and progress of this modeling approach concerning the relations between these mathematical structures within this overall framework.

  18. Rats' performance on variable-interval schedules with a linear feedback loop between response rate and reinforcement rate.

    PubMed Central

    Reed, Phil; Hildebrandt, Tom; DeJongh, Julie; Soh, Mariane

    2003-01-01

    Three experiments investigated whether rats are sensitive to the molar properties of a variable-interval (VI) schedule with a positive relation between response rate and reinforcement rate (i.e., a VI+ schedule). In Experiment 1, rats responded faster on a variable ratio (VR) schedule than on a VI+ schedule with an equivalent feedback function. Reinforced interresponse times (IRTs) were shorter on the VR as compared to the VI+ schedule. In Experiments 2 and 3, there was no systematic difference in response rates maintained by a VI+ schedule and a VI schedule yoked in terms of reinforcement rate. This was found both when the yoking procedure was between-subject (Experiment 2) and within-subject (Experiment 3). Mean reinforced IRTs were similar on both the VI+ and yoked VI schedules, but these values were more variable on the VI+ schedule. These results provided no evidence that rats are sensitive to the feedback function relating response rate to reinforcement rate on a VI+ schedule. PMID:12822684

  19. Rats' choices with token stimuli in concurrent variable-interval schedules.

    PubMed

    Mazur, James E

    2014-09-01

    Four rats responded on concurrent variable-interval schedules that delivered token stimuli (stimulus lights arranged vertically above each of two side levers). During exchange periods, each token could be exchanged for one food pellet by responding on a center lever, with one response required for each pellet delivery. In different conditions, the exchange requirements (number of tokens that had to be earned before they could be exchanged for food) varied between one and four for the two response levers. The experiments were closely patterned after research with pigeons by Mazur and Biondi (2013), and the results from the rats in the present experiment were similar. Response percentages on the two levers changed as each additional token was earned, and these patterns indicated that choice was controlled by both the time to the exchange periods and the number of food pellets that were delivered in the exchange period. In some conditions, the exchange requirement was three tokens for each lever, but the token lights were not turned on as they were earned for one of the two keys. The rats showed a slight preference for the lever without the token lights, which may indicate that the token lights were not serving as conditioned reinforcers (a result also found by Mazur and Biondi with pigeons). Overall, these results suggest that, in this choice procedure, the token stimuli served primarily as discriminative stimuli that signaled the temporal proximity and quantity of the primary reinforcer, food. PMID:25130299

  20. Comparing Pleasure and Pain: The Fundamental Mathematical Equivalence of Reward Gain and Shock Reduction under Variable Interval Schedules

    ERIC Educational Resources Information Center

    Mallpress, Dave E. W.; Fawcett, Tim W.; McNamara, John M.; Houston, Alasdair I.

    2012-01-01

    The relationship between positive and negative reinforcement and the symmetry of Thorndike's law of effect are unresolved issues in operant psychology. Here we show that, for a given pattern of responding on variable interval (VI) schedules with the same programmed rate of food rewards (positive reinforcement VI) or electric shocks (negative…

  1. Molecular analyses of the effects of d-amphetamine on fixed-interval schedule performances of rats.

    PubMed Central

    McAuley, F; Leslie, J C

    1986-01-01

    A series of doses (0.5 to 2.0 mg/kg) of d-amphetamine was administered to rats whose lever pressing was maintained by fixed-interval 30-s, 60-s, or 120-s schedules of reinforcement by sucrose delivery. Under both saline and d-amphetamine conditions, molecular features of responding were reliably described in terms of the distribution of postreinforcement pauses and local response rate following the onset of responding. Postreinforcement pause always varied from interval to interval but, on average, shortened under the drug. Local response rate (response rate exclusive of pause time) tended to decrease under the drug, and where acceleration occurred within runs of responses, it was reduced by the drug. All of these effects were dose-related. These findings suggest that fixed-interval behavior can be analyzed effectively at a molecular level, and that the effects of d-amphetamine are best described as disruption of temporal discrimination. PMID:3958666

  2. Tolerance to Effects of Cocaine on Behavior under a Response-Initiated Fixed-Interval Schedule

    ERIC Educational Resources Information Center

    Weaver, Matthew T.; Branch, Marc N.

    2008-01-01

    Tolerance to effects of cocaine can be modulated by schedules of reinforcement. With multiple ratio schedules, research has shown an inverse relationship between ratio requirement and amount of tolerance that resulted from daily administration of the drug. In contrast, tolerance to the effects of cocaine on behavior under multiple interval…

  3. Effects of Cocaine on Performance under Fixed-Interval Schedules with a Small Tandem Ratio Requirement

    ERIC Educational Resources Information Center

    Pinkston, Jonathan W.; Branch, Marc N.

    2004-01-01

    Daily administration of cocaine often results in the development of tolerance to its effects on responding maintained by fixed-ratio schedules. Such effects have been observed to be greater when the ratio value is small, whereas less or no tolerance has been observed at large ratio values. Similar schedule-parameter-dependent tolerance, however,…

  4. Auditory Model: Effects on Learning under Blocked and Random Practice Schedules

    ERIC Educational Resources Information Center

    Han, Dong-Wook; Shea, Charles H.

    2008-01-01

    An experiment was conducted to determine the impact of an auditory model on blocked, random, and mixed practice schedules of three five-segment timing sequences (relative time constant). We were interested in whether or not the auditory model differentially affected the learning of relative and absolute timing under blocked and random practice.…

  5. Pigeons' wait-time responses to transitions in interfood-interval duration: Another look at cyclic schedule performance

    PubMed Central

    Higa, Jennifer J.; Thaw, Jean M.; Staddon, John E. R.

    1993-01-01

    Recent developments reveal that animals can rapidly learn about intervals of time. We studied the nature of this fast-acting process in two experiments. In Experiment 1 pigeons were exposed to a modified fixed-time schedule, in which the time between food rewards (interfood interval) changed at an unpredictable point in each session, either decreasing from 15 to 5 s (step-down) or increasing from 15 to 45 s (step-up). The birds were able to track under both conditions by producing postreinforcement wait times proportional to the preceding interfood-interval duration. However, the time course of responding differed: Tracking was apparently more gradual in the step-up condition. Experiment 2 studied the effect of having both kinds of transitions within the same session by exposing pigeons to a repeating (cyclic) sequence of the interfood-interval values used in Experiment 1. Pigeons detected changes in the input sequence of interfood intervals, but only for a few sessions—discrimination worsened with further training. The dynamic effects we observed do not support a linear waiting process of time discrimination, but instead point to a timing mechanism based on the frequency and recency of prior interfood intervals and not the preceding interfood interval alone. PMID:16812693

  6. Flexibility of Oral Cholera Vaccine Dosing—A Randomized Controlled Trial Measuring Immune Responses Following Alternative Vaccination Schedules in a Cholera Hyper-Endemic Zone

    PubMed Central

    Kanungo, Suman; Desai, Sachin N.; Nandy, Ranjan Kumar; Bhattacharya, Mihir Kumar; Kim, Deok Ryun; Sinha, Anuradha; Mahapatra, Tanmay; Yang, Jae Seung; Lopez, Anna Lena; Manna, Byomkesh; Bannerjee, Barnali; Ali, Mohammad; Dhingra, Mandeep Singh; Chandra, Ananga Mohan; Clemens, John D.; Sur, Dipika; Wierzba, Thomas F.

    2015-01-01

    Background A bivalent killed whole cell oral cholera vaccine has been found to be safe and efficacious for five years in the cholera endemic setting of Kolkata, India, when given in a two dose schedule, two weeks apart. A randomized controlled trial revealed that the immune response was not significantly increased following the second dose compared to that after the first dose. We aimed to evaluate the impact of an extended four week dosing schedule on vibriocidal response. Methodology/Principal Findings In this double blind randomized controlled non-inferiority trial, 356 Indian, non-pregnant residents aged 1 year or older were randomized to receive two doses of oral cholera vaccine at 14 and 28 day intervals. We compared vibriocidal immune responses between these schedules. Among adults, no significant differences were noted when comparing the rates of seroconversion for V. cholerae O1 Inaba following two dose regimens administered at a 14 day interval (55%) vs the 28 day interval (58%). Similarly, no differences in seroconversion were demonstrated in children comparing the 14 (80%) and 28 day intervals (77%). Following 14 and 28 day dosing intervals, vibriocidal response rates against V. cholerae O1 Ogawa were 45% and 49% in adults and 73% and 72% in children respectively. Responses were lower for V. cholerae O139, but similar between dosing schedules for adults (20%, 20%) and children (28%, 20%). Conclusions/Significance Comparable immune responses and safety profiles between the two dosing schedules support the option for increased flexibility of current OCV dosing. Further operational research using a longer dosing regimen will provide answers to improve implementation and delivery of cholera vaccination in endemic and epidemic outbreak scenarios. PMID:25764513

  7. On scheduling models for the frequency interval assignment problem with cumulative interferences

    NASA Astrophysics Data System (ADS)

    Kiatmanaroj, Kata; Artigues, Christian; Houssin, Laurent

    2016-05-01

    In this article, models and methods for solving a real-life frequency assignment problem based on scheduling theory are investigated. A realistic frequency assignment problem involving cumulative interference constraints in which the aim is to maximize the number of assigned users is considered. If interferences are assumed to be binary, a multiple carrier frequency assignment problem can be treated as a disjunctive scheduling problem since a user requesting a number of contiguous frequencies can be considered as a non-preemptive task with a processing time, and two interfering users can be modelled through a disjunctive constraint on the corresponding tasks. A binary interference version of the problem is constructed and a disjunctive scheduling model is derived. Based on the binary representation, two models are proposed. The first one relies on an interference matrix and the second one considers maximal cliques. A third, cumulative, model that yields a new class of scheduling problems is also proposed. Computational experiments show that the case-study frequency assignment problem can be solved efficiently with disjunctive scheduling techniques.

  8. The Effects of Initial Interval Size on the Efficacy of DRO Schedules of Reinforcement.

    ERIC Educational Resources Information Center

    Repp, Alan C.; And Others

    1991-01-01

    This study examined effect of initial differential reinforcement of other behavior (DRO) intervals on disruptive behavior of nine students with moderate disabilities. Results indicate initial DRO value equal to the mean number of intervals between responses in baseline was much more effective than a value twice that size. (Author/PB)

  9. Inner Random Restart Genetic Algorithm for Practical Delivery Schedule Optimization

    NASA Astrophysics Data System (ADS)

    Sakurai, Yoshitaka; Takada, Kouhei; Onoyama, Takashi; Tsukamoto, Natsuki; Tsuruta, Setsuo

    A delivery route optimization that improves the efficiency of real time delivery or a distribution network requires solving several tens to hundreds but less than 2 thousands cities Traveling Salesman Problems (TSP) within interactive response time (less than about 3 second), with expert-level accuracy (less than about 3% of error rate). Further, to make things more difficult, the optimization is subjects to special requirements or preferences of each various delivery sites, persons, or societies. To meet these requirements, an Inner Random Restart Genetic Algorithm (Irr-GA) is proposed and developed. This method combines meta-heuristics such as random restart and GA having different types of simple heuristics. Such simple heuristics are 2-opt and NI (Nearest Insertion) methods, each applied for gene operations. The proposed method is hierarchical structured, integrating meta-heuristics and heuristics both of which are multiple but simple. This method is elaborated so that field experts as well as field engineers can easily understand to make the solution or method easily customized and extended according to customers' needs or taste. Comparison based on the experimental results and consideration proved that the method meets the above requirements more than other methods judging from not only optimality but also simplicity, flexibility, and expandability in order for this method to be practically used.

  10. Accelerated Hepatitis B Vaccine Schedule among Drug Users – A Randomized Controlled Trial

    PubMed Central

    Hwang, Lu-Yu; Grimes, Carolyn Z.; Tran, Thanh Quoc; Clark, April; Xia, Rui; Lai, Dejian; Troisi, Catherine; Williams, Mark

    2010-01-01

    Background Hepatitis B vaccine provides a model for improving uptake and completion of multi-dose vaccinations in the drug-using community. Methods DASH project conducted randomized controlled trial among not-in-treatment current drug users in two urban neighborhoods. Neighborhoods were cluster-randomized to receive a standard (HIV information) or enhanced (HBV vaccine acceptance/adherence) behavioral intervention; participants within clusters were randomized to a standard (0, 1, 6 mo) or accelerated (0, 1, 2 mo) vaccination schedule. Outcomes were completion of three-dose vaccine and HBV seroprotection. Results Of those screening negative for HIV/HBV, 77% accepted HB vaccination and 75% of those received all 3 doses. Injecting drug users (IDUs) on the accelerated schedule were significantly more likely to receive 3 doses (76%) than those on the standard schedule (66%, p=.04), although for drug users as a whole the adherence was 77% and 73%. No difference in adherence was observed between behavioral intervention groups. Predictors of adherence were older age, African American race, stable housing, and alcohol use. Cumulative HBV seroprotection (≥10 mIU/mL) was gained by 12 months by 65% of those completing. Seroprotection at 6 months was greater for the accelerated schedule group. Conclusions The accelerated vaccine schedule improves hepatitis B vaccination adherence among IDU. PMID:20936979

  11. When Repetition Isn't the Best Practice Strategy: Effects of Blocked and Random Practice Schedules

    ERIC Educational Resources Information Center

    Stambaugh, Laura A.

    2011-01-01

    The purpose of this study was to investigate the effects of blocked and random practice schedules on the performance accuracy, speed, temporal evenness, and attitude of beginning band students in a group instructional setting. The research assumptions were based on the contextual interference hypothesis, which predicts that a blocked practice…

  12. The effects of initial interval size on the efficacy of DRO schedules of reinforcement.

    PubMed

    Repp, A C; Felce, D; Barton, L E

    1991-01-01

    The differential reinforcement of other behavior (DRO) is a behavior-reduction procedure that has been popular for several years. In classroom settings, it provides reinforcement when a student does not display inappropriate responding for a particular interval of time. Unfortunately, relatively little is known about how to use DRO effectively in applied settings. Most research has been conducted in laboratory settings; the purpose of the present study was to provide a replication of one of those studies. This study examined the effect of the size of the initial DRO interval on the disruptive behavior of students with moderate disabilities. In the first experiment, a group of six students was observed during baseline in two classes. Two different DRO values were then used. In one classroom, it was equal to the mean number of 10-second intervals between disruptions during baseline. In the other classroom, it was twice the mean number during baseline. In the final phase, behavior in both classrooms was put under the same DRO program. In the second experiment, the disruptive behavior of three students was studied in a different design in which both methods of determining the initial DRO value were compared. The results of both experiments showed that an initial DRO value equal to the mean number of intervals between responses in baseline was much more effective than a value twice that size in reducing disruptions. PMID:2022233

  13. Confidence intervals for the selected population in randomized trials that adapt the population enrolled

    PubMed Central

    Rosenblum, Michael

    2014-01-01

    It is a challenge to design randomized trials when it is suspected that a treatment may benefit only certain subsets of the target population. In such situations, trial designs have been proposed that modify the population enrolled based on an interim analysis, in a preplanned manner. For example, if there is early evidence during the trial that the treatment only benefits a certain subset of the population, enrollment may then be restricted to this subset. At the end of such a trial, it is desirable to draw inferences about the selected population. We focus on constructing confidence intervals for the average treatment effect in the selected population. Confidence interval methods that fail to account for the adaptive nature of the design may fail to have the desired coverage probability. We provide a new procedure for constructing confidence intervals having at least 95% coverage probability, uniformly over a large class Q of possible data generating distributions. Our method involves computing the minimum factor c by which a standard confidence interval must be expanded in order to have, asymptotically, at least 95% coverage probability, uniformly over Q. Computing the expansion factor c is not trivial, since it is not a priori clear, for a given decision rule, which data generating distribution leads to the worst-case coverage probability. We give an algorithm that computes c, and prove an optimality property for the resulting confidence interval procedure. PMID:23553577

  14. An Exploration of Remote History Effects in Humans: II. The Effects under Fixed-Interval, Variable-Interval, and Fixed-Ratio Schedules

    ERIC Educational Resources Information Center

    Okouchi, Hiroto

    2010-01-01

    Five undergraduates responded under a fixed-ratio (FR) 145 schedule, and 5 others responded under a differential-reinforcement-of-low-rate (DRL) 20-s schedule. Both groups were then exposed to a differential-reinforcement-of-rates- with-pacing 1 s less than interresponse time (IRT) less than or equal to 2 s schedule. Following this, probe sessions…

  15. Effects of concurrent random-time schedules on the spatial distribution of behavior in rats.

    PubMed

    Ribes-Iñesta, Emilio; Torres, Carlos; Correa, Laura; Montes, Edgar

    2006-07-01

    We evaluated the effects of concurrent random temporal contingencies of water delivery on the location of rats' behavior. In this experiment, two concurrent random-time schedules delivered water in two dispensers that were located at opposite ends of the chamber, and provided complementary frequencies of water deliveries while the overall number of deliveries stayed constant. Time allocation in the areas adjacent to each water dispenser covaried with water deliveries, although no proportional relation was found. Rats showed a preference for the area where water was initially presented. The results point to the importance of examining spatial properties and patterning of behavior. PMID:16530984

  16. Response Strength in Extreme Multiple Schedules

    ERIC Educational Resources Information Center

    McLean, Anthony P.; Grace, Randolph C.; Nevin, John A.

    2012-01-01

    Four pigeons were trained in a series of two-component multiple schedules. Reinforcers were scheduled with random-interval schedules. The ratio of arranged reinforcer rates in the two components was varied over 4 log units, a much wider range than previously studied. When performance appeared stable, prefeeding tests were conducted to assess…

  17. Single-Sample Discrimination of Different Schedules' Reinforced Interresponse Times

    ERIC Educational Resources Information Center

    Tanno, Takayuki; Silberberg, Alan; Sakagami, Takayuki

    2009-01-01

    Food-deprived rats in Experiment 1 responded to one of two tandem schedules that were, with equal probability, associated with a sample lever. The tandem schedules' initial links were different random-interval schedules. Their values were adjusted to approximate equality in time to completing each tandem schedule's response requirements. The…

  18. Confidence intervals for demographic projections based on products of random matrices.

    PubMed

    Heyde, C C; Cohen, J E

    1985-04-01

    This work is concerned with the growth of age-structured populations whose vital rates vary stochastically in time and with the provision of confidence intervals. In this paper a model Yt + 1(omega) = Xt + 1(omega) Yt(omega) is considered, where Yt is the (column) vector of the numbers of individuals in each age class at time t, X is a matrix of vital rates, and omega refers to a particular realization of the process that produces the vital rates. It is assumed that (Xi) is a stationary sequence of random matrices with nonnegative elements and that there is an integer n0 such that any product Xj + n0...Xj + 1Xj has all its elements positive with probability one. Then, under mild additional conditions, strong laws of large numbers and central limit results are obtained for the logarithms of the components of Yt. Large-sample estimators of the parameters in these limit results are derived. From these, confidence intervals on population growth and growth rates can be constructed. Various finite-sample estimators are studied numerically. The estimators are then used to study the growth of the striped bass population breeding in the Potomac River of the eastern United States. PMID:4023951

  19. A modified hybrid uncertain analysis method for dynamic response field of the LSOAAC with random and interval parameters

    NASA Astrophysics Data System (ADS)

    Zi, Bin; Zhou, Bin

    2016-07-01

    For the prediction of dynamic response field of the luffing system of an automobile crane (LSOAAC) with random and interval parameters, a hybrid uncertain model is introduced. In the hybrid uncertain model, the parameters with certain probability distribution are modeled as random variables, whereas, the parameters with lower and upper bounds are modeled as interval variables instead of given precise values. Based on the hybrid uncertain model, the hybrid uncertain dynamic response equilibrium equation, in which different random and interval parameters are simultaneously included in input and output terms, is constructed. Then a modified hybrid uncertain analysis method (MHUAM) is proposed. In the MHUAM, based on random interval perturbation method, the first-order Taylor series expansion and the first-order Neumann series, the dynamic response expression of the LSOAAC is developed. Moreover, the mathematical characteristics of extrema of bounds of dynamic response are determined by random interval moment method and monotonic analysis technique. Compared with the hybrid Monte Carlo method (HMCM) and interval perturbation method (IPM), numerical results show the feasibility and efficiency of the MHUAM for solving the hybrid LSOAAC problems. The effects of different uncertain models and parameters on the LSOAAC response field are also investigated deeply, and numerical results indicate that the impact made by the randomness in the thrust of the luffing cylinder F is larger than that made by the gravity of the weight in suspension Q . In addition, the impact made by the uncertainty in the displacement between the lower end of the lifting arm and the luffing cylinder a is larger than that made by the length of the lifting arm L .

  20. Choice Behavior in Pigeons Maintained with Probabilistic Schedules of Reinforcement

    ERIC Educational Resources Information Center

    Moore, Jay; Friedlen, Karen E.

    2007-01-01

    Pigeons were trained in three experiments with a two-key, concurrent-chains choice procedure. The initial links were equal variable-interval schedules, and the terminal links were random-time schedules with equal average interreinforcement intervals. Across the three experiments, the pigeons either stayed in a terminal link until a reinforcer was…

  1. A new hierarchical method for inter-patient heartbeat classification using random projections and RR intervals

    PubMed Central

    2014-01-01

    Background The inter-patient classification schema and the Association for the Advancement of Medical Instrumentation (AAMI) standards are important to the construction and evaluation of automated heartbeat classification systems. The majority of previously proposed methods that take the above two aspects into consideration use the same features and classification method to classify different classes of heartbeats. The performance of the classification system is often unsatisfactory with respect to the ventricular ectopic beat (VEB) and supraventricular ectopic beat (SVEB). Methods Based on the different characteristics of VEB and SVEB, a novel hierarchical heartbeat classification system was constructed. This was done in order to improve the classification performance of these two classes of heartbeats by using different features and classification methods. First, random projection and support vector machine (SVM) ensemble were used to detect VEB. Then, the ratio of the RR interval was compared to a predetermined threshold to detect SVEB. The optimal parameters for the classification models were selected on the training set and used in the independent testing set to assess the final performance of the classification system. Meanwhile, the effect of different lead configurations on the classification results was evaluated. Results Results showed that the performance of this classification system was notably superior to that of other methods. The VEB detection sensitivity was 93.9% with a positive predictive value of 90.9%, and the SVEB detection sensitivity was 91.1% with a positive predictive value of 42.2%. In addition, this classification process was relatively fast. Conclusions A hierarchical heartbeat classification system was proposed based on the inter-patient data division to detect VEB and SVEB. It demonstrated better classification performance than existing methods. It can be regarded as a promising system for detecting VEB and SVEB of unknown patients in

  2. Initial Investigations of Controller Tools and Procedures for Schedule-Based Arrival Operations with Mixed Flight-Deck Interval Management Equipage

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.; Cabrall, Christopher; Kupfer, Michael; Omar, Faisal G.; Prevot, Thomas

    2012-01-01

    NASA?s Air Traffic Management Demonstration-1 (ATD-1) is a multi-year effort to demonstrate high-throughput, fuel-efficient arrivals at a major U.S. airport using NASA-developed scheduling automation, controller decision-support tools, and ADS-B-enabled Flight-Deck Interval Management (FIM) avionics. First-year accomplishments include the development of a concept of operations for managing scheduled arrivals flying Optimized Profile Descents with equipped aircraft conducting FIM operations, and the integration of laboratory prototypes of the core ATD-1 technologies. Following each integration phase, a human-in-the-loop simulation was conducted to evaluate and refine controller tools, procedures, and clearance phraseology. From a ground-side perspective, the results indicate the concept is viable and the operations are safe and acceptable. Additional training is required for smooth operations that yield notable benefits, particularly in the areas of FIM operations and clearance phraseology.

  3. Is walking a random walk? Evidence for long-range correlations in stride interval of human gait

    NASA Technical Reports Server (NTRS)

    Hausdorff, Jeffrey M.; Peng, C.-K.; Ladin, Zvi; Wei, Jeanne Y.; Goldberger, Ary L.

    1995-01-01

    Complex fluctuation of unknown origin appear in the normal gait pattern. These fluctuations might be described as being (1) uncorrelated white noise, (2) short-range correlations, or (3) long-range correlations with power-law scaling. To test these possibilities, the stride interval of 10 healthy young men was measured as they walked for 9 min at their usual rate. From these time series we calculated scaling indexes by using a modified random walk analysis and power spectral analysis. Both indexes indicated the presence of long-range self-similar correlations extending over hundreds of steps; the stride interval at any time depended on the stride interval at remote previous times, and this dependence decayed in a scale-free (fractallike) power-law fashion. These scaling indexes were significantly different from those obtained after random shuffling of the original time series, indicating the importance of the sequential ordering of the stride interval. We demonstrate that conventional models of gait generation fail to reproduce the observed scaling behavior and introduce a new type of central pattern generator model that sucessfully accounts for the experimentally observed long-range correlations.

  4. A random-key encoded harmony search approach for energy-efficient production scheduling with shared resources

    NASA Astrophysics Data System (ADS)

    Garcia-Santiago, C. A.; Del Ser, J.; Upton, C.; Quilligan, F.; Gil-Lopez, S.; Salcedo-Sanz, S.

    2015-11-01

    When seeking near-optimal solutions for complex scheduling problems, meta-heuristics demonstrate good performance with affordable computational effort. This has resulted in a gravitation towards these approaches when researching industrial use-cases such as energy-efficient production planning. However, much of the previous research makes assumptions about softer constraints that affect planning strategies and about how human planners interact with the algorithm in a live production environment. This article describes a job-shop problem that focuses on minimizing energy consumption across a production facility of shared resources. The application scenario is based on real facilities made available by the Irish Center for Manufacturing Research. The formulated problem is tackled via harmony search heuristics with random keys encoding. Simulation results are compared to a genetic algorithm, a simulated annealing approach and a first-come-first-served scheduling. The superior performance obtained by the proposed scheduler paves the way towards its practical implementation over industrial production chains.

  5. Timing of HPV vaccine intervals among United States teens with consideration to the current ACIP schedule and the WHO 2-dose schedule.

    PubMed

    Cloessner, Emily A; Stokley, Shannon; Yankey, David; Markowitz, Lauri E

    2016-06-01

    The current recommendation for human papillomavirus (HPV) vaccination in the United States is for 3 doses to be administered over a 6 month period. In April 2014, the World Health Organization (WHO) recommended adoption of a 2-dose schedule, with doses spaced a minimum of 6 months apart, for teens who begin the series before age 15. We analyzed data from the 2013 National Immunization Survey-Teen to examine the timing of second and third dose receipt among US adolescents. All analyses were restricted to adolescents age 13-17 y who had adequate provider data. The Wilcoxon-Mann-Whitney test measured differences in time to receive vaccine doses among demographic and socioeconomic groups. Logistic regression identified socioeconomic characteristics associated with receiving the second dose of HPV vaccine at least 6 months after the first dose. The median time for teens to receive the second dose of HPV vaccine was 2.6 months after the first dose, and the median time to receive the third dose was 4.9 months after the second dose. Minority teens and teens living below the poverty level took significantly longer to receive doses. Among teens that initiated the HPV vaccine series before age 15 y, 28.6% received the second dose at least 6 months after the first dose. If these teens, who met the WHO criteria for up-to-date HPV vaccination, were classified as having completed the vaccination series, overall coverage in the US would increase 3.9 percentage points, with African American and Hispanic teens having the greatest increases in coverage. PMID:26587886

  6. Comparing Fixed- And Randomized-Interval Spaced Retrieval in Anomia Treatment

    ERIC Educational Resources Information Center

    Morrow, K. Leigh; Fridriksson, Julius

    2006-01-01

    Spaced retrieval (SR) has recently been modified to target anomia in persons with aphasia (PWA). It relies on a strict management of the inter-stimulus interval (ISI) where the time between stimulus presentations is doubled or halved based on response accuracy. Although SR is successful in treating anomia, it remains to be studied whether the…

  7. An Adaptive Randomized Trial of an Intermittent Dosing Schedule of Aerosolized Ribavirin in Patients With Cancer and Respiratory Syncytial Virus Infection

    PubMed Central

    Chemaly, Roy F.; Torres, Harrys A.; Munsell, Mark F.; Shah, Dimpy P.; Rathod, Dhanesh B.; Bodey, Gerald P.; Hosing, Chitra; Saifan, Chadi; Raad, Issam I.; Champlin, Richard E.

    2012-01-01

    A continuous dosing schedule of aerosolized ribavirin has been used for respiratory syncytial virus (RSV) upper respiratory tract infection and lower respiratory tract infection (LRTI) but is associated with high cost and inconvenient administration. We conducted an adaptive randomized trial to evaluate the effectiveness of an intermittent dosing schedule of ribavirin versus that of a continuous dosing schedule of ribavirin in preventing RSV LRTIs in 50 hematopoietic stem cell transplant recipients or patients with hematologic malignancies. LRTI occurred in 3 patients (9%) receiving the intermittent schedule and in 4 (22%) receiving the continuous schedule, with a 0.889 posterior probability. Because the intermittent schedule is easy to administer and has a higher efficacy than the continuous schedule, we recommend the intermittent schedule for patients who are at risk for RSV LRTI. Clinical Trials Registration. NCT00500578. PMID:22927454

  8. Transfer function analysis of the autonomic response to respiratory activity during random interval breathing

    NASA Technical Reports Server (NTRS)

    Chen, M. H.; Berger, R. D.; Saul, J. P.; Stevenson, K.; Cohen, R. J.

    1987-01-01

    We report a new method for the noninvasive characterization of the frequency response of the autonomic nervous system (ANS) in mediating fluctuations in heart rate (HR). The approach entails computation of the transfer function magnitude and phase between instantaneous lung volume and HR. Broad band fluctuations in lung volume were initiated when subjects breathed on cue to a sequence of beeps spaced randomly in time. We studied 10 subjects in both supine and standing positions. The transfer function, averaged among all the subjects, showed systematic differences between the two postures, reflecting the differing frequency responses of the sympathetic and parasympathetic divisions of the ANS.

  9. On the comparison of the interval estimation of the Pareto parameter under simple random sampling and ranked set sampling techniques

    NASA Astrophysics Data System (ADS)

    Aissa, Aissa Omar; Ibrahim, Kamarulzaman; Dayyeh, Walid Abu; Zin, Wan Zawiah Wan

    2015-02-01

    Ranked set sampling (RSS) is recognized as a useful sampling scheme for improving the precision of the parameter estimates and increasing the efficiency of estimation. This type of scheme is appropriate when the variable of interest is expensive or time consuming to be quantified, but easy and cheap to be ranked. In this study, the estimation of the shape parameter of the Pareto distribution of the first type when the scale is known is studied for the data that are gathered under simple random sampling (SRS), RSS, and selective order statistics based on the maximum (SORSS(max)). The confidence intervals for the shape parameter of Pareto distribution under the sampling techniques considered are determined. A simulation study is carried out to compare the confidence intervals in terms of coverage probabilities (CPs) and expected lengths (ELs). When the coverage probabilities and expected lengths for the confidence intervals of the shape parameter of Pareto distribution determined based on the different sampling methods are compared, the coverage probabilities and expected lengths are found to be more precise under RSS as opposed to SRS. In particular, it is found that the coverage probabilities under SORSS(max) is closest to the nominal value of 0.95.

  10. Effect of Dexmedetomidine on Heart Rate-Corrected QT and Tpeak-Tend Intervals During Robot-Assisted Laparoscopic Prostatectomy With Steep Trendelenburg Position: A Prospective, Randomized, Double-Blinded, Controlled Study.

    PubMed

    Kim, Na Young; Han, Dong Woo; Koh, Jae Chul; Rha, Koon Ho; Hong, Jung Hwa; Park, Jong Min; Kim, So Yeon

    2016-05-01

    Intraperitoneal insufflation of carbon dioxide may affect the sympathetic activity that leads to changes in ventricular repolarization. This in turn can result in changes of heart rate-corrected QT (QTc) interval and Tpeak-Tend (Tp-e) interval. Dexmedetomidine is a highly selective α2-receptor agonist and has potential antiarrhythmic properties. This prospective, randomized, double-blinded, controlled study evaluated the effects of dexmedetomidine administration on QTc and Tp-e intervals during robot-assisted laparoscopic prostatectomy with steep Trendelenburg position.Fifty patients scheduled for robot-assisted laparoscopic prostatectomy randomly received either a continuous infusion of dexmedetomidine at a rate of 0.3 μg/kg/hour, from anesthetic induction until the end of the Trendelenburg position (dexmedetomidine group; n = 25), or the same volume of normal saline (control group; n = 25). Anesthesia was maintained with sevoflurane and remifentanil. The primary and secondary goals were to evaluate the effect of dexmedetomidine on the QTc and Tp-e interval changes. Mean arterial pressure, heart rate, end-tidal CO2, and end-tidal sevoflurane concentrations were assessed as well.Forty-seven patients (94%) completed the study. Dexmedetomidine significantly attenuated QTc interval prolongation and reduced the Tp-e interval, even though the baseline values of the QTc and Tp-e intervals were similar between the 2 groups (PGroup × Time = 0.001 and 0.014, respectively). Twenty-two patients (96%) in the control group and 13 (54%) in the dexmedetomidine group had QTc interval prolongation of >20 ms from the baseline value during surgery (P = 0.001). The maximum QTc interval prolongation from the baseline value during surgery was 46 ± 21 ms in the control group and 24 ± 21 ms in the dexmedetomidine group (mean ± SD, P = 0.001). Mean arterial pressure and heart rate were comparable between the groups.Continuous infusion of

  11. A 3-week multimodal intervention involving high-intensity interval training in female cancer survivors: a randomized controlled trial.

    PubMed

    Schmitt, Joachim; Lindner, Nathalie; Reuss-Borst, Monika; Holmberg, Hans-Christer; Sperlich, Billy

    2016-02-01

    To compare the effects of a 3-week multimodal rehabilitation involving supervised high-intensity interval training (HIIT) on female breast cancer survivors with respect to key variables of aerobic fitness, body composition, energy expenditure, cancer-related fatigue, and quality of life to those of a standard multimodal rehabilitation program. A randomized controlled trial design was administered. Twenty-eight women, who had been treated for cancer were randomly assigned to either a group performing exercise of low-to-moderate intensity (LMIE; n = 14) or a group performing high-intensity interval training (HIIT; n = 14) as part of a 3-week multimodal rehabilitation program. No adverse events related to the exercise were reported. Work economy improved following both HIIT and LMIE, with improved peak oxygen uptake following LMIE. HIIT reduced mean total body fat mass with no change in body mass, muscle or fat-free mass (best P < 0.06). LMIE increased muscle and total fat-free body mass. Total energy expenditure (P = 0.45) did not change between the groups, whereas both improved quality of life to a similar high extent and lessened cancer-related fatigue. This randomized controlled study demonstrates that HIIT can be performed by female cancer survivors without adverse health effects. Here, HIIT and LMIE both improved work economy, quality of life and cancer-related fatigue, body composition or energy expenditure. Since the outcomes were similar, but HIIT takes less time, this may be a time-efficient strategy for improving certain aspects of the health of female cancer survivors. PMID:26869680

  12. On the gap and time interval between the first two maxima of long continuous time random walks

    NASA Astrophysics Data System (ADS)

    Mounaix, Philippe; Schehr, Grégory; Majumdar, Satya N.

    2016-01-01

    We consider a one-dimensional continuous time random walk (CTRW) on a fixed time interval T where at each time step the walker waits a random time τ, before performing a jump drawn from a symmetric continuous probability distribution function (PDF) f(η ) , of Lévy index 0<μ ≤slant 2 . Our study includes the case where the waiting time PDF \\Psi(τ ) has a power law tail, \\Psi(τ )\\propto {τ-1-γ} , with 0<γ <1 , such that the average time between two consecutive jumps is infinite. The random motion is sub-diffusive if γ <μ /2 (and super-diffusive if γ >μ /2 ). We investigate the joint PDF of the gap g between the first two highest positions of the CTRW and the time t separating these two maxima. We show that this PDF reaches a stationary limiting joint distribution p(g, t) in the limit of long CTRW, T\\to ∞ . Our exact analytical results show a very rich behavior of this joint PDF in the (γ,μ ) plane, which we study in great detail. Our main results are verified by numerical simulations. This work provides a non trivial extension to CTRWs of the recent study in the discrete time setting by Majumdar et al (2014 J. Stat. Mech. P09013).

  13. Prime-Boost Interval Matters: A Randomized Phase 1 Study to Identify the Minimum Interval Necessary to Observe the H5 DNA Influenza Vaccine Priming Effect

    PubMed Central

    Ledgerwood, Julie E.; Zephir, Kathryn; Hu, Zonghui; Wei, Chih-Jen; Chang, LeeJah; Enama, Mary E.; Hendel, Cynthia S.; Sitar, Sandra; Bailer, Robert T.; Koup, Richard A.; Mascola, John R.; Nabel, Gary J.; Graham, Barney S.

    2013-01-01

    Background. H5 DNA priming was previously shown to improve the antibody response to influenza A(H5N1) monovalent inactivated vaccine (MIV) among individuals for whom there was a 24-week interval between prime and boost receipt. This study defines the shortest prime-boost interval associated with an improved response to MIV. Methods. We administered H5 DNA followed by MIV at intervals of 4, 8, 12, 16, or 24 weeks and compared responses to that of 2 doses of MIV (prime-boost interval, 24 weeks). Results. H5 DNA priming with an MIV boost ≥12 weeks later showed an improved response, with a positive hemagglutination inhibition (HAI) titer in 91% of recipients (geometric mean titer [GMT], 141–206), compared with 55%–70% of recipients with an H5 DNA and MIV prime-boost interval of ≤8 weeks (GMT, 51–70) and 44% with an MIV-MIV prime-boost interval of 24 weeks (GMT, 27). Conclusion. H5 DNA priming enhances antibody responses after an MIV boost when the prime-boost interval is 12–24 weeks. Clinical Trials Registration. NCT01086657. PMID:23633407

  14. Analysis of using interpulse intervals to generate 128-bit biometric random binary sequences for securing wireless body sensor networks.

    PubMed

    Zhang, Guang-He; Poon, Carmen C Y; Zhang, Yuan-Ting

    2012-01-01

    Wireless body sensor network (WBSN), a key building block for m-Health, demands extremely stringent resource constraints and thus lightweight security methods are preferred. To minimize resource consumption, utilizing information already available to a WBSN, particularly common to different sensor nodes of a WBSN, for security purposes becomes an attractive solution. In this paper, we tested the randomness and distinctiveness of the 128-bit biometric binary sequences (BSs) generated from interpulse intervals (IPIs) of 20 healthy subjects as well as 30 patients suffered from myocardial infarction and 34 subjects with other cardiovascular diseases. The encoding time of a biometric BS on a WBSN node is on average 23 ms and memory occupation is 204 bytes for any given IPI sequence. The results from five U.S. National Institute of Standards and Technology statistical tests suggest that random biometric BSs can be generated from both healthy subjects and cardiovascular patients and can potentially be used as authentication identifiers for securing WBSNs. Ultimately, it is preferred that these biometric BSs can be used as encryption keys such that key distribution over the WBSN can be avoided. PMID:22049370

  15. Scheduling Randomly-Deployed Heterogeneous Video Sensor Nodes for Reduced Intrusion Detection Time

    NASA Astrophysics Data System (ADS)

    Pham, Congduc

    This paper proposes to use video sensor nodes to provide an efficient intrusion detection system. We use a scheduling mechanism that takes into account the criticality of the surveillance application and present a performance study of various cover set construction strategies that take into account cameras with heterogeneous angle of view and those with very small angle of view. We show by simulation how a dynamic criticality management scheme can provide fast event detection for mission-critical surveillance applications by increasing the network lifetime and providing low stealth time of intrusions.

  16. Changes in QTc Interval in the Citalopram for Agitation in Alzheimer's Disease (CitAD) Randomized Trial

    PubMed Central

    Drye, Lea T.; Spragg, David; Devanand, D. P.; Frangakis, Constantine; Marano, Christopher; Meinert, Curtis L.; Mintzer, Jacobo E.; Munro, Cynthia A.; Pelton, Gregory; Pollock, Bruce G.; Porsteinsson, Anton P.; Rabins, Peter V.; Rosenberg, Paul B.; Schneider, Lon S.; Shade, David M.; Weintraub, Daniel; Yesavage, Jerome; Lyketsos, Constantine G.

    2014-01-01

    Background A Food and Drug Administration (FDA) safety communication in August 2011 warned that citalopram was associated with a dose dependent risk of QT prolongation and recommended dose restriction in patients over the age of 60 but did not provide data for this age group. Methods CitAD was a randomized, double-masked, placebo-controlled, multicenter clinical trial for agitation in Alzheimer's disease (AD). Participants were assigned to citalopram (target dose of 30 mg/day) or placebo in a 1∶1 ratio. 186 people, 181 of whom were over the age of 60, having probable AD with clinically significant agitation were recruited from September 2009 to January 2013. After the FDA safety communication about citalopram, ECG was added to the required study procedures before enrollment and repeated at week 3 to monitor change in QTc interval. Forty-eight participants were enrolled after enhanced monitoring began. Results Citalopram treatment was associated with a larger increase in QTc interval than placebo (difference in week 3 QTc adjusting for baseline QTc: 18.1 ms [95% CI: 6.1, 30.1]; p = 0.004). More participants in the citalopram group had an increase ≥30 ms from baseline to week 3 (7 in citalopram versus 1 in placebo; Fisher's exact p = 0.046), but only slightly more in the citalopram group met a gender-specific threshold for prolonged QTc (450 ms for males; 470 ms for females) at any point during follow-up (3 in citalopram versus 1 in placebo, Fisher's exact p = 0.611). One of the citalopram participants who developed prolonged QTc also displayed ventricular bigeminy. No participants in either group had a cardiovascular-related death. Conclusion Citalopram at 30 mg/day was associated with improvement in agitation in patients with AD but was also associated with QT prolongation. Trial Registration ClinicalTrials.gov NCT00898807 PMID:24914549

  17. The Effect of Green Tea Ingestion and Interval Sprinting Exercise on the Body Composition of Overweight Males: A Randomized Trial.

    PubMed

    Gahreman, Daniel; Heydari, Mehrdad; Boutcher, Yati; Freund, Judith; Boutcher, Stephen

    2016-01-01

    The combined effect of green tea ingestion and interval sprinting exercise on body and abdominal fat of overweight males was investigated. Participants were randomly assigned into control (C), green tea (GT), interval sprinting exercise (ISE), and green tea and ISE (GT + ISE) groups. The GT, GT + ISE, and C groups consumed three GT capsules daily. The ISE and GT + ISE groups completed 36 ISE sessions over 12 weeks. Forty eight overweight males with a mean BMI of 28.5 ± 0.92 kg/m² and age of 26 ± 0.7 years acted as participants. There was a significant reduction in total and abdominal fat mass for the ISE and GT + ISE groups, p < 0.05, however, total and abdominal fat mass did not significantly change in the GT and C groups. There was a significant increase in total lean mass, p < 0.05, after the intervention for the ISE and GT + ISE groups only. There was a significant increase in fat oxidation during submaximal aerobic exercise, p < 0.05, after the intervention for the ISE, GT + ISE, and GT groups with no change for the C group. Following the 12-week intervention the ISE and GT + ISE groups, compared to C, recorded a significantly greater decrease in body and abdominal fat, and a significant increase in total lean mass. Ingestion of green tea by itself, however, did not result in a significant decrease in body or abdominal fat, but increased fat utilization during submaximal exercise. The combination of 12 weeks of GT ingestion and ISE did not result in greater total and abdominal fat reduction compared to 12 weeks of ISE alone. PMID:27548216

  18. The Effect of Green Tea Ingestion and Interval Sprinting Exercise on the Body Composition of Overweight Males: A Randomized Trial

    PubMed Central

    Gahreman, Daniel; Heydari, Mehrdad; Boutcher, Yati; Freund, Judith; Boutcher, Stephen

    2016-01-01

    The combined effect of green tea ingestion and interval sprinting exercise on body and abdominal fat of overweight males was investigated. Participants were randomly assigned into control (C), green tea (GT), interval sprinting exercise (ISE), and green tea and ISE (GT + ISE) groups. The GT, GT + ISE, and C groups consumed three GT capsules daily. The ISE and GT + ISE groups completed 36 ISE sessions over 12 weeks. Forty eight overweight males with a mean BMI of 28.5 ± 0.92 kg/m2 and age of 26 ± 0.7 years acted as participants. There was a significant reduction in total and abdominal fat mass for the ISE and GT + ISE groups, p < 0.05, however, total and abdominal fat mass did not significantly change in the GT and C groups. There was a significant increase in total lean mass, p < 0.05, after the intervention for the ISE and GT + ISE groups only. There was a significant increase in fat oxidation during submaximal aerobic exercise, p < 0.05, after the intervention for the ISE, GT + ISE, and GT groups with no change for the C group. Following the 12-week intervention the ISE and GT + ISE groups, compared to C, recorded a significantly greater decrease in body and abdominal fat, and a significant increase in total lean mass. Ingestion of green tea by itself, however, did not result in a significant decrease in body or abdominal fat, but increased fat utilization during submaximal exercise. The combination of 12 weeks of GT ingestion and ISE did not result in greater total and abdominal fat reduction compared to 12 weeks of ISE alone. PMID:27548216

  19. Population pharmacokinetics and exploratory pharmacodynamics of ifosfamide according to continuous or short infusion schedules: an n = 1 randomized study

    PubMed Central

    Brain, Etienne G C; Rezai, Kevan; Lokiec, François; Gutierrez, Maya; Urien, Saïk

    2008-01-01

    AIMS To model the pharmacokinetics and pharmacodynamics of ifosfamide and its key metabolites. The pharmacodynamic parameters included were renal toxicity and myelosuppression measured using urinary β2-microglobulin (BMG) and absolute neutrophil count (ANC), respectively. METHODS Seventeen patients were enrolled into an n = 1 randomized trial during two consecutive cycles of ifosfamide 9 g m−2 during each cycle given by a 3 h or 72 h infusion. Data were analyzed using NONMEM. RESULTS Ifosfamide and metabolite concentration–time profiles were described by a one-compartment open-model with auto-induction of clearance. BMG and ANC time-courses were related to ifosfamide concentration via indirect response models. CONCLUSIONS This modelling allowed the simulation of weekly schedules of flat doses with favourable myelotoxic profiles. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT The optimal infusion duration for ifosfamide remains to be determined.No differences according to time of infusion have been identified in traditional pharmacokinetic endpoints, such as area under the curve.The impact on pharmacodynamics has never been modelled or correlated with pharmacokinetics. WHAT THIS STUDY ADDS The pharmacokinetics and pharmacodynamics of ifosfamide and its main metabolites can both be modelled with no influence of infusion duration.Pharmacodynamic modelling (renal and haematological toxicity) allows further simulations of new schedules with favourable toxicity profiles. PMID:18294323

  20. Preliminary efficacy and feasibility of embedding high intensity interval training into the school day: A pilot randomized controlled trial

    PubMed Central

    Costigan, S.A.; Eather, N.; Plotnikoff, R.C.; Taaffe, D.R.; Pollock, E.; Kennedy, S.G.; Lubans, D.R.

    2015-01-01

    Current physical activity and fitness levels among adolescents are low, increasing the risk of chronic disease. Although the efficacy of high intensity interval training (HIIT) for improving metabolic health is now well established, it is not known if this type of activity can be effective to improve adolescent health. The primary aim of this study is to assess the effectiveness and feasibility of embedding HIIT into the school day. A 3-arm pilot randomized controlled trial was conducted in one secondary school in Newcastle, Australia. Participants (n = 65; mean age = 15.8(0.6) years) were randomized into one of three conditions: aerobic exercise program (AEP) (n = 21), resistance and aerobic exercise program (RAP) (n = 22) and control (n = 22). The 8-week intervention consisted of three HIIT sessions per week (8–10 min/session), delivered during physical education (PE) lessons or at lunchtime. Assessments were conducted at baseline and post-intervention to detect changes in cardiorespiratory fitness (multi-stage shuttle-run), muscular fitness (push-up, standing long jump tests), body composition (Body Mass Index (BMI), BMI-z scores, waist circumference) and physical activity motivation (questionnaire), by researchers blinded to treatment allocation. Intervention effects for outcomes were examined using linear mixed models, and Cohen's d effect sizes were reported. Participants in the AEP and RAP groups had moderate intervention effects for waist circumference (p = 0.024), BMI-z (p = 0.037) and BMI (not significant) in comparison to the control group. A small intervention effect was also evident for cardiorespiratory fitness in the RAP group. PMID:26844177

  1. Preliminary efficacy and feasibility of embedding high intensity interval training into the school day: A pilot randomized controlled trial.

    PubMed

    Costigan, S A; Eather, N; Plotnikoff, R C; Taaffe, D R; Pollock, E; Kennedy, S G; Lubans, D R

    2015-01-01

    Current physical activity and fitness levels among adolescents are low, increasing the risk of chronic disease. Although the efficacy of high intensity interval training (HIIT) for improving metabolic health is now well established, it is not known if this type of activity can be effective to improve adolescent health. The primary aim of this study is to assess the effectiveness and feasibility of embedding HIIT into the school day. A 3-arm pilot randomized controlled trial was conducted in one secondary school in Newcastle, Australia. Participants (n = 65; mean age = 15.8(0.6) years) were randomized into one of three conditions: aerobic exercise program (AEP) (n = 21), resistance and aerobic exercise program (RAP) (n = 22) and control (n = 22). The 8-week intervention consisted of three HIIT sessions per week (8-10 min/session), delivered during physical education (PE) lessons or at lunchtime. Assessments were conducted at baseline and post-intervention to detect changes in cardiorespiratory fitness (multi-stage shuttle-run), muscular fitness (push-up, standing long jump tests), body composition (Body Mass Index (BMI), BMI-z scores, waist circumference) and physical activity motivation (questionnaire), by researchers blinded to treatment allocation. Intervention effects for outcomes were examined using linear mixed models, and Cohen's d effect sizes were reported. Participants in the AEP and RAP groups had moderate intervention effects for waist circumference (p = 0.024), BMI-z (p = 0.037) and BMI (not significant) in comparison to the control group. A small intervention effect was also evident for cardiorespiratory fitness in the RAP group. PMID:26844177

  2. Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States

    PubMed Central

    Steimer, Andreas; Schindler, Kaspar

    2015-01-01

    Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon’s implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike’s preceding ISI. As we show, the EIF’s exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron’s ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing

  3. Behavioral effects of nicotine, amphetamine and cocaine under a fixed-interval schedule of food reinforcement in rats chronically exposed to caffeine.

    PubMed

    Jaszyna, M; Gasior, M; Shoaib, M; Yasar, S; Goldberg, S R

    1998-12-01

    Epidemiological surveys demonstrate that caffeine, the main psychoactive ingredient of coffee, is a positive correlate in drug abuse. To characterize the behavioral nature of caffeine interactions with other psychomotor stimulants, we examined the effects of chronic caffeine exposure on the behavioral responses to nicotine, amphetamine, cocaine, the selective D1 agonist SKF-82958 and the selective D2 receptor agonist NPA, in rats responding under a fixed interval (FI) schedule of food reinforcement. Following stabilization of rates and temporal patterns of responding (mathematically expressed as quarter-life values, QL), twenty-one Sprague-Dawley rats responding under a 5-min FI schedule of food reinforcement were divided into two groups; one (twelve rats) maintained on tap water (control) and the other (nine rats) on caffeine (3 mg/ml added to the drinking water). Following the substitution of caffeine solution for tap water, behavior was temporarily disrupted as evidenced by decreases in responding and QL values which reached a maximum after 72 h (rate 60% and QL 30% below baseline levels). Rats developed complete tolerance to these effects of caffeine over 5 days of caffeine exposure. After response rate and QL values stabilized, effects of drugs were evaluated. Nicotine (0.01-1.0 mg/kg; SC), amphetamine (0.1-5.6; IP), and cocaine (1.0-17; IP) each produced biphasic dose-dependent changes in response rate with maximum increases in response rate following intermediate doses and decreases in response rates following higher doses. The increase in rates of responding produced by amphetamine or cocaine (but not nicotine) were greater (P<0.05) in caffeine-drinking than in water-drinking rats. Both SKF-82958 (0.001-0.3 mg/kg; IP) and NPA (0.0001-0.1; IP) produced only dose-dependent decreases in rates of responding. Caffeine-drinking rats were less sensitive to the rate-depressant effects of SKF-82958 (P<0.05) than water-drinking rats. However, similar changes (P>0

  4. Confidence Intervals, Power Calculation, and Sample Size Estimation for the Squared Multiple Correlation Coefficient under the Fixed and Random Regression Models: A Computer Program and Useful Standard Tables.

    ERIC Educational Resources Information Center

    Mendoza, Jorge L.; Stafford, Karen L.

    2001-01-01

    Introduces a computer package written for Mathematica, the purpose of which is to perform a number of difficult iterative functions with respect to the squared multiple correlation coefficient under the fixed and random models. These functions include computation of the confidence interval upper and lower bounds, power calculation, calculation of…

  5. High Intensity Interval- vs Moderate Intensity- Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trial

    PubMed Central

    Fisher, Gordon; Brown, Andrew W.; Bohan Brown, Michelle M.; Alcorn, Amy; Noles, Corey; Winwood, Leah; Resuehr, Holly; George, Brandon; Jeansonne, Madeline M.; Allison, David B.

    2015-01-01

    Purpose To compare the effects of six weeks of high intensity interval training (HIIT) vs continuous moderate intensity training (MIT) for improving body composition, insulin sensitivity (SI), blood pressure, blood lipids, and cardiovascular fitness in a cohort of sedentary overweight or obese young men. We hypothesized that HIIT would result in similar improvements in body composition, cardiovascular fitness, blood lipids, and SI as compared to the MIT group, despite requiring only one hour of activity per week compared to five hours per week for the MIT group. Methods 28 sedentary overweight or obese men (age, 20 ± 1.5 years, body mass index 29.5 ± 3.3 kg/m2) participated in a six week exercise treatment. Participants were randomly assigned to HIIT or MIT and evaluated at baseline and post-training. DXA was used to assess body composition, graded treadmill exercise test to measure cardiovascular fitness, oral glucose tolerance to measure SI, nuclear magnetic resonance spectroscopy to assess lipoprotein particles, and automatic auscultation to measure blood pressure. Results A greater improvement in VO2peak was observed in MIT compared to HIIT (11.1% vs 2.83%, P = 0.0185) in the complete-case analysis. No differences were seen in the intention to treat analysis, and no other group differences were observed. Both exercise conditions were associated with temporal improvements in % body fat, total cholesterol, medium VLDL, medium HDL, triglycerides, SI, and VO2peak (P < 0.05). Conclusion Participation in HIIT or MIT exercise training displayed: 1) improved SI, 2) reduced blood lipids, 3) decreased % body fat, and 4) improved cardiovascular fitness. While both exercise groups led to similar improvements for most cardiometabolic risk factors assessed, MIT led to a greater improvement in overall cardiovascular fitness. Overall, these observations suggest that a relatively short duration of either HIIT or MIT training may improve cardiometabolic risk factors in

  6. Influence of Inter-Training Intervals on Intermanual Transfer Effects in Upper-Limb Prosthesis Training: A Randomized Pre-Posttest Study

    PubMed Central

    Romkema, Sietske; Bongers, Raoul M.; van der Sluis, Corry K.

    2015-01-01

    Improvement in prosthetic training using intermanual transfer (the transfer of motor skills from the trained, “unaffected” hand to the untrained, “affected” hand) has been shown in previous studies. The aim of this study is to determine the influence of the inter-training interval on the magnitude of the intermanual transfer effects. This was done using a mechanistic, randomized, single-blinded pretest-posttest design. Sixty-four able-bodied, right-handed participants were randomly assigned to the Short and Long Interval Training Groups and the Short and Long Interval Control Groups. The Short and Long Interval Training Groups used a prosthesis simulator in their training program. The Short and Long Interval Control Groups executed a sham training program, that is, a dummy training program in which the same muscles were trained as with the prosthesis simulator. The Short Interval Training Group and the Short Interval Control Groups trained on consecutive days, while the Long Interval Training Group and Long Interval Control Group trained twice a week. To determine the improvement in skills, a test was administered before, immediately after, and at two points in time after the training. Training was performed with the “unaffected” arm; tests were performed with the “affected” arm. The outcome measurements were: the movement time (the time from the beginning of the movement until completion of the task); the duration of maximum hand opening, (the opening of the prosthetic hand while grasping an object); and the grip-force control (the error from the required grip-force during a tracking task). Intermanual transfer was found in movement times, but not in hand opening or grip-force control. The length of the inter-training interval did not affect the magnitude of intermanual transfer effects. No difference in the intermanual transfer effect in upper-limb prosthesis training was found for training on a daily basis as compared to training twice a week

  7. Too Much of a Good Thing: Random Practice Scheduling and Self-Control of Feedback Lead to Unique but Not Additive Learning Benefits

    PubMed Central

    Ali, Asif; Fawver, Bradley; Kim, Jingu; Fairbrother, Jeffrey; Janelle, Christopher M.

    2012-01-01

    We examined the impact of self-controlled knowledge of results on the acquisition, retention, and transfer of anticipation timing skill as a function of random and blocked practice schedules. Forty-eight undergraduate students were divided into experimental groups that practiced under varying combinations of random or blocked as well as self-controlled or yoked practice conditions. Anticipation timing performance (5, 13, and 21 mph) was recorded during acquisition and during a short term no-feedback retention test. A transfer test, administered 24 h after the retention test, consisted of two novel anticipation timing speeds (9, 17 mph). Absolute error (AE) and variable error (VE) of timing served as the dependent measures. All participants improved their accuracy and consistency across acquisition blocks; however, those who practiced under blocked rather than random conditions had greater accuracy (lower AE) regardless of feedback delivery. During retention and transfer, those who practiced under random conditions showed greater consistency (lower VE) compared to their blocked counterparts. Finally, participants who controlled their feedback schedule were more accurate (lower AE) and less variable (lower VE) during transfer compared to yoked participants, regardless of practice scheduling. Our findings indicate that practicing under a random schedule improves retention and transfer consistency, while self-control of feedback is advantageous to both the accuracy and consistency with which anticipation timing skill transfers to novel task demands. The combination of these learning manipulations, however, does not improve skill retention or transfer above and beyond their orthogonal effects. PMID:23233843

  8. A critical appraisal of the evidence for using cardiotocography plus ECG ST interval analysis for fetal surveillance in labor. Part I: the randomized controlled trials

    PubMed Central

    Olofsson, Per; Ayres-de-Campos, Diogo; Kessler, Jörg; Tendal, Britta; Yli, Branka M; Devoe, Lawrence

    2014-01-01

    We reappraised the five randomized controlled trials that compared cardiotocography plus ECG ST interval analysis (CTG+ST) vs. cardiotocography. The numbers enrolled ranged from 5681 (Dutch randomized controlled trial) to 799 (French randomized controlled trial). The Swedish randomized controlled trial (n = 5049) was the only trial adequately powered to show a difference in metabolic acidosis, and the Plymouth randomized controlled trial (n = 2434) was only powered to show a difference in operative delivery for fetal distress. There were considerable differences in study design: the French randomized controlled trial used different inclusion criteria, and the Finnish randomized controlled trial (n = 1483) used a different metabolic acidosis definition. In the CTG+ST study arms, the larger Plymouth, Swedish and Dutch trials showed lower operative delivery and metabolic acidosis rates, whereas the smaller Finnish and French trials showed minor differences in operative delivery and higher metabolic acidosis rates. We conclude that the differences in outcomes are likely due to the considerable differences in study design and size. This will enhance heterogeneity effects in any subsequent meta-analysis. PMID:24797452

  9. Sustained immunogenicity of the HPV-16/18 AS04-adjuvanted vaccine administered as a two-dose schedule in adolescent girls: Five-year clinical data and modeling predictions from a randomized study

    PubMed Central

    Romanowski, Barbara; Schwarz, Tino F; Ferguson, Linda; Peters, Klaus; Dionne, Marc; Behre, Ulrich; Schulze, Karin; Hillemanns, Peter; Suryakiran, Pemmaraju; Thomas, Florence; Struyf, Frank

    2016-01-01

    In this randomized, partially-blind study (clinicaltrials.gov; NCT00541970), the licensed formulation of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine (20 μg each of HPV-16/18 antigens) was found highly immunogenic up to 4 y after first vaccination, whether administered as a 2-dose (2D) schedule in girls 9–14 y or 3-dose (3D) schedule in women 15–25 y. This end-of-study analysis extends immunogenicity and safety data until Month (M) 60, and presents antibody persistence predictions estimated by piecewise and modified power law models. Healthy females (age stratified: 9–14, 15–19, 20–25 y) were randomized to receive 2D at M0,6 (N = 240 ) or 3D at M0,1,6 (N = 239). Here, results are reported for girls 9–14 y (2D) and women 15–25 y (3D). Seropositivity rates, geometric mean titers (by enzyme-linked immunosorbent assay) and geometric mean titer ratios (GMRs; 3D/2D; post-hoc exploratory analysis) were calculated. All subjects seronegative pre-vaccination in the according-to-protocol immunogenicity cohort were seropositive for anti-HPV-16 and −18 at M60. Antibody responses elicited by the 2D and 3D schedules were comparable at M60, with GMRs close to 1 (anti-HPV-16: 1.13 [95% confidence interval: 0.82–1.54]; anti-HPV-18: 1.06 [0.74–1.51]). Statistical modeling predicted that in 95% of subjects, antibodies induced by 2D and 3D schedules could persist above natural infection levels for ≥ 21 y post-vaccination. The vaccine had a clinically acceptable safety profile in both groups. In conclusion, a 2D M0,6 schedule of the HPV-16/18 AS04-adjuvanted vaccine was immunogenic for up to 5 y in 9–14 y-old girls. Statistical modeling predicted that 2D-induced antibodies could persist for longer than 20 y. PMID:26176261

  10. Using a Nonparametric Bootstrap to Obtain a Confidence Interval for Pearson's "r" with Cluster Randomized Data: A Case Study

    ERIC Educational Resources Information Center

    Wagstaff, David A.; Elek, Elvira; Kulis, Stephen; Marsiglia, Flavio

    2009-01-01

    A nonparametric bootstrap was used to obtain an interval estimate of Pearson's "r," and test the null hypothesis that there was no association between 5th grade students' positive substance use expectancies and their intentions to not use substances. The students were participating in a substance use prevention program in which the unit of…

  11. Randomized Controlled Trial of RTS,S/AS02D and RTS,S/AS01E Malaria Candidate Vaccines Given According to Different Schedules in Ghanaian Children

    PubMed Central

    Owusu-Agyei, Seth; Ansong, Daniel; Asante, Kwaku; Kwarteng Owusu, Sandra; Owusu, Ruth; Wireko Brobby, Naana Ayiwa; Dosoo, David; Osei Akoto, Alex; Osei-Kwakye, Kingsley; Adjei, Emmanuel Asafo; Boahen, Kwadwo Owusu; Sylverken, Justice; Adjei, George; Sambian, David; Apanga, Stephen; Kayan, Kingsley; Vekemans, Johan; Ofori-Anyinam, Opokua; Leach, Amanda; Lievens, Marc; Demoitie, Marie-Ange; Dubois, Marie-Claude; Cohen, Joe; Ballou, W. Ripley; Savarese, Barbara; Chandramohan, Daniel; Gyapong, John Owusu; Milligan, Paul; Antwi, Sampson; Agbenyega, Tsiri; Greenwood, Brian; Evans, Jennifer

    2009-01-01

    Background The target delivery channel of RTS,S candidate malaria vaccines in malaria-endemic countries in Africa is the World Health Organisation Expanded Program on Immunization. As an Adjuvant System, age de-escalation and schedule selection step, this study assessed 3 schedules of RTS,S/AS01E and RTS,S/AS02D in infants and young children 5–17 months of age in Ghana. Methodology A Phase II, partially-blind randomized controlled study (blind to vaccine, not to schedule), of 19 months duration was conducted in two (2) centres in Ghana between August 2006 and May 2008. Subjects were allocated randomly (1∶1∶1∶1∶1∶1) to one of six study groups at each study site, each defining which vaccine should be given and by which schedule (0,1-, 0,1,2- or 0,1,7-months). For the 0,1,2-month schedule participants received RTS,S/AS01E or rabies vaccine at one center and RTS,S/AS01E or RTS,S/AS02D at the other. For the other schedules at both study sites, they received RTS,S/AS01E or RTS,S/AS02D. The primary outcome measure was the occurrence of serious adverse events until 10 months post dose 1. Results The number of serious adverse events reported across groups was balanced. One child had a simple febrile convulsion, which evolved favourably without sequelae, considered to be related to RTS,S/AS01E vaccination. Low grade reactions occurred slightly more frequently in recipients of RTS,S/AS than rabies vaccines; grade 3 reactions were infrequent. Less local reactogenicity occurred with RTS,S/AS01E than RTS,S/AS02D. Both candidate vaccines were highly immunogenic for anti-circumsporozoite and anti-Hepatitis B Virus surface antigen antibodies. Recipients of RTS,S/AS01E compared to RTS,S/AS02D had higher peak anti-circumsporozoite antibody responses for all 3 schedules. Three dose schedules were more immunogenic than 2 dose schedules. Area under the curve analyses for anti-circumsporozoite antibodies were comparable between the 0,1,2- and 0,1,7-month RTS,S/AS01E schedules

  12. Patient safety, resident well-being and continuity of care with different resident duty schedules in the intensive care unit: a randomized trial

    PubMed Central

    Parshuram, Christopher S.; Amaral, Andre C.K.B.; Ferguson, Niall D.; Baker, G. Ross; Etchells, Edward E.; Flintoft, Virginia; Granton, John; Lingard, Lorelei; Kirpalani, Haresh; Mehta, Sangeeta; Moldofsky, Harvey; Scales, Damon C.; Stewart, Thomas E.; Willan, Andrew R.; Friedrich, Jan O.

    2015-01-01

    Background: Shorter resident duty periods are increasingly mandated to improve patient safety and physician well-being. However, increases in continuity-related errors may counteract the purported benefits of reducing fatigue. We evaluated the effects of 3 resident schedules in the intensive care unit (ICU) on patient safety, resident well-being and continuity of care. Methods: Residents in 2 university-affiliated ICUs were randomly assigned (in 2-month rotation-blocks from January to June 2009) to in-house overnight schedules of 24, 16 or 12 hours. The primary patient outcome was adverse events. The primary resident outcome was sleepiness, measured by the 7-point Stanford Sleepiness Scale. Secondary outcomes were patient deaths, preventable adverse events, and residents’ physical symptoms and burnout. Continuity of care and perceptions of ICU staff were also assessed. Results: We evaluated 47 (96%) of 49 residents, all 971 admissions, 5894 patient-days and 452 staff surveys. We found no effect of schedule (24-, 16- or 12-h shifts) on adverse events (81.3, 76.3 and 78.2 events per 1000 patient-days, respectively; p = 0.7) or on residents’ sleepiness in the daytime (mean rating 2.33, 2.61 and 2.30, respectively; p = 0.3) or at night (mean rating 3.06, 2.73 and 2.42, respectively; p = 0.2). Seven of 8 preventable adverse events occurred with the 12-hour schedule (p = 0.1). Mortality rates were similar for the 3 schedules. Residents’ somatic symptoms were more severe and more frequent with the 24-hour schedule (p = 0.04); however, burnout was similar across the groups. ICU staff rated residents’ knowledge and decision-making worst with the 16-hour schedule. Interpretation: Our findings do not support the purported advantages of shorter duty schedules. They also highlight the trade-offs between residents’ symptoms and multiple secondary measures of patient safety. Further delineation of this emerging signal is required before widespread system change. Trial

  13. Simulated annealing and metaheuristic for randomized priority search algorithms for the aerial refuelling parallel machine scheduling problem with due date-to-deadline windows and release times

    NASA Astrophysics Data System (ADS)

    Kaplan, Sezgin; Rabadi, Ghaith

    2013-01-01

    This article addresses the aerial refuelling scheduling problem (ARSP), where a set of fighter jets (jobs) with certain ready times must be refuelled from tankers (machines) by their due dates; otherwise, they reach a low fuel level (deadline) incurring a high cost. ARSP is an identical parallel machine scheduling problem with release times and due date-to-deadline windows to minimize the total weighted tardiness. A simulated annealing (SA) and metaheuristic for randomized priority search (Meta-RaPS) with the newly introduced composite dispatching rule, apparent piecewise tardiness cost with ready times (APTCR), are applied to the problem. Computational experiments compared the algorithms' solutions to optimal solutions for small problems and to each other for larger problems. To obtain optimal solutions, a mixed integer program with a piecewise weighted tardiness objective function was solved for up to 12 jobs. The results show that Meta-RaPS performs better in terms of average relative error but SA is more efficient.

  14. Programming with Intervals

    NASA Astrophysics Data System (ADS)

    Matsakis, Nicholas D.; Gross, Thomas R.

    Intervals are a new, higher-level primitive for parallel programming with which programmers directly construct the program schedule. Programs using intervals can be statically analyzed to ensure that they do not deadlock or contain data races. In this paper, we demonstrate the flexibility of intervals by showing how to use them to emulate common parallel control-flow constructs like barriers and signals, as well as higher-level patterns such as bounded-buffer producer-consumer. We have implemented intervals as a publicly available library for Java and Scala.

  15. Randomized Crossover Study to Examine the Necessity of an Injection-to-Meal Interval in Patients With Type 2 Diabetes and Human Insulin

    PubMed Central

    Müller, Nicolle; Frank, Thomas; Kloos, Christof; Lehmann, Thomas; Wolf, Gunter; Müller, Ulrich Alfons

    2013-01-01

    OBJECTIVE Patients with diabetes and insulin therapy with human insulin were usually instructed to use an interval of 20–30 min between the injection and meal. We examined the necessity of the injection-to-meal interval (IMI) in patients with type 2 diabetes mellitus (T2DM) and flexible insulin therapy with human insulin. RESEARCH DESIGN AND METHODS In this randomized, open crossover trial, 100 patients with T2DM (47% men, mean age = 66.7 years) were randomized to the IMI first group (phase 1, IMI 20 min; phase 2, no IMI) or IMI last group (phase 1, no IMI; phase 2, IMI 20 min). The main outcome measures were HbA1c, blood glucose profile, incidence of hypoglycemia, quality of life, treatment satisfaction, and patient preference. RESULTS Forty-nine patients were randomized to the IMI first group and 51 patients to the IMI last group. Omitting the IMI only slightly increases HbA1c (average intraindividual difference = 0.08% [95% CI 0.01–0.15]). Since the difference is not clinically relevant, a therapy without IMI is noninferior to its application (P < 0.001). In the secondary outcomes, the incidence of mild hypoglycemia also did not differ between no IMI and IMI significantly (mean of differences = −0.10, P = 0.493). No difference in the blood glucose profile of both groups was found. Treatment satisfaction increased markedly, by 8.08, if IMI was omitted (P < 0.001). The total score of the quality of life measure did not show differences between applying an IMI or not. Insulin therapy without IMI was preferred by 86.5% of patients (P < 0.001). CONCLUSIONS An IMI for patients with T2DM and preprandial insulin therapy is not necessary. PMID:23340895

  16. Quality-of-Life Comparisons in a Randomized Trial of Interval Secondary Cytoreduction in Advanced Ovarian Carcinoma: A Gynecologic Oncology Group Study

    PubMed Central

    Wenzel, Lari; Huang, Helen Q.; Monk, Bradley J.; Rose, Peter G.; Cella, David

    2016-01-01

    Purpose To compare self-reported quality of life (QOL) in patients who did versus did not undergo interval secondary cytoreduction after initial surgery and combination chemotherapy for advanced ovarian cancer and to assess the association between baseline QOL scores and survival. Patients and Methods Consenting patients participating in a Gynecologic Oncology Group (GOG) phase III treatment trial (GOG 152) completed the Functional Assessment of Cancer Therapy–Ovarian (FACT-O) questionnaire and treatment-specific supplemental questions at the third and sixth chemotherapy cycles and at 6 and 12 months after starting treatment. Results For all patients, QOL decreased approximately 1 unit from the first to second assessment. Significant improvement observed at 6 months (P < .001) was sustained at 12 months, with no appreciable between-group difference. The baseline FACT-O score was associated with overall survival (P = .048) but not progression-free survival. Less neurotoxicity was reported among patients who did (38.4%) versus did not (54.0%) undergo interval secondary cytoreduction at the third assessment (P = .005), and older patients experienced more long-term effects. Conclusion This is the first multicenter randomized trial in ovarian cancer to longitudinally examine self-reported QOL and establish a predictive value of baseline QOL on survival, attributed primarily to the lowest-scoring quartile. Although interval secondary cytoreduction resulted in no notable long-term difference, a clinically significant improvement was seen in both arms at 6 and 12 months after starting therapy. Interestingly, there were fewer complaints of neurotoxicity at 6 months among patients who did versus did not undergo interval secondary cytoreduction. PMID:16110020

  17. Randomized Multicenter Phase II Trial Comparing Two Schedules of Etirinotecan Pegol (NKTR-102) in Women With Recurrent Platinum-Resistant/Refractory Epithelial Ovarian Cancer

    PubMed Central

    Vergote, Ignace B.; Garcia, Agustin; Micha, John; Pippitt, Charles; Bendell, Johanna; Spitz, Daniel; Reed, Nicholas; Dark, Graham; Fracasso, Paula M.; Ibrahim, Emad N.; Armenio, Vincent A.; Duska, Linda; Poole, Chris; Gennigens, Christine; Dirix, Luc Y.; Leung, Abraham C.F.; Zhao, Carol; Soufi-Mahjoubi, Raoudha; Rustin, Gordon

    2013-01-01

    Purpose Etirinotecan pegol (NKTR-102) is a unique, long-acting topoisomerase-I inhibitor with prolonged systemic exposure to SN38 (7-ethyl-10-hydroxycamptothecin), the active metabolite of irinotecan. This randomized phase II trial investigated two dosing schedules of etirinotecan pegol in patients with platinum-resistant/refractory ovarian carcinoma. Patients and Methods A total of 71 eligible patients were randomly assigned to receive etirinotecan pegol 145 mg/m2 every 14 or 21 days until progression or unacceptable adverse events (AEs). The primary end point was objective response rate (ORR) by RECIST (version 1.0). Secondary end points included response by Gynecologic Cancer Intergroup criteria, duration of ORR, progression-free survival (PFS), and overall survival (OS). Results The overall confirmed ORR was 20% (95% CI, 10% to 30%): 20% for once every 14 days, and 19% for once every 21 days. Median response duration was 4.1 months for once every 14 days and 4.0 months for once every 21 days. Median PFS for every 14 and every 21 days was 4.1 and 5.3 months, respectively, and median OS was 10.0 and 11.7 months, respectively. Etirinotecan pegol was well tolerated, with the most common grade 3 to 4 AEs being dehydration (24%) and diarrhea (23%). Diarrhea, dehydration, nausea, and neutropenia were less frequent with the schedule of once every 21 days than with that of once every 14 days. Conclusion Both schedules of etirinotecan pegol showed activity in patients with heavily pretreated ovarian cancer, with encouraging ORR and PFS rates. The schedule of once every 21 days was better tolerated and had slightly longer PFS and OS rates. The treatment schedule of etirinotecan pegol 145 mg/m2 once every 21 days was selected for the expanded phase II study and is preferred for future phase III studies. These findings provide support to directly compare etirinotecan pegol versus one of the approved drugs (eg, pegylated liposomal doxorubicin or topotecan) in platinum

  18. Flexible Scheduling.

    ERIC Educational Resources Information Center

    Davis, Harold S.; Bechard, Joseph E.

    A flexible schedule allows teachers to change group size, group composition, and class length according to the purpose of the lesson. This pamphlet presents various "master" schedules for flexible scheduling: (1) Simple block schedules, (2) back-to-back schedules, (3) interdisciplinary schedules, (4) school-wide block schedules, (5) open-lab…

  19. The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial

    PubMed Central

    2009-01-01

    Background High-intensity interval training has been shown to be a time-efficient way to induce physiological adaptations similar to those of traditional endurance training. Creatine supplementation may enhance high-intensity interval training, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of high-intensity interval training (HIIT) and creatine supplementation on cardiorespiratory fitness and endurance performance (maximal oxygen consumption (VO2PEAK), time-to-exhaustion (VO2PEAKTTE), ventilatory threshold (VT), and total work done (TWD)) in college-aged men. Methods Forty-three recreationally active men completed a graded exercise test to determine VO2PEAK, VO2PEAKTTE, and VT. In addition, participants completed a time to exhaustion (TTE) ride at 110% of the maximum workload reached during the graded exercise test to determine TWD (TTE (sec) × W = J). Following testing, participants were randomly assigned to one of three groups: creatine (creatine citrate) (Cr; n = 16), placebo (PL; n = 17), or control (n = 10) groups. The Cr and PL groups completed four weeks of HIIT prior to post-testing. Results Significant improvements in VO2PEAK and VO2PEAKTTE occurred in both training groups. Only the Cr group significantly improved VT (16% vs. 10% improvement in PL). No changes occurred in TWD in any group. Conclusion In conclusion, HIIT is an effective and time-efficient way to improve maximal endurance performance. The addition of Cr improved VT, but did not increase TWD. Therefore, 10 g of Cr per day for five days per week for four weeks does not seem to further augment maximal oxygen consumption, greater than HIIT alone; however, Cr supplementation may improve submaximal exercise performance. PMID:19909536

  20. Schedule-induced licking during multiple schedules1

    PubMed Central

    Jacquet, Yasuko Filby

    1972-01-01

    Schedule-induced polydipsia was studied in rats bar pressing under two-component multiple schedules of food reinforcement. The first component of the multiple schedule was a variable-interval 1-min schedule throughout the experiment. The schedule comprising the second component was varied over blocks of sessions in terms of rate and magnitude of reinforcement, and was either variable-interval 3-min (one pellet), variable-interval 3-min (three pellets), variable-interval 1-min (one pellet), or extinction. Water intake per session varied with the rate of reinforcement in the schedule comprising the second component and was highest when the schedule was variable-interval 1-min. Both bar-pressing behavior and licking behavior showed behavioral interactions between the two components of the multiple schedules. With magnitude of reinforcement held constant, a matching relationship was observed between lick rate and reinforcement rate; the relative frequency of licks in the constant component matched the relative frequency of reinforcement in that component. Bar pressing, however, showed only a moderate degree of relativity matching. During the schedule-induced licking, a burst of licking followed each delivery of a pellet (post-prandial drinking). The duration of these bursts of licking was observed to be a function of the inter-reinforcement interval. PMID:16811598

  1. Predicting scheduling success

    NASA Technical Reports Server (NTRS)

    Messing, Fredric

    1993-01-01

    This paper provides an analytical formulation to predict scheduling success for a class of problems frequently referred to as activity scheduling. Space Network communications scheduling is an example of activity scheduling. The principal assumption is that the activity start times are randomly distributed over the available time in the time line. The formulation makes it possible to estimate how much of the demand can be scheduled as a function of the demand, number of resources, activity duration, and activity flexibility. The paper includes computed results for a variety of resource and demand conditions. The results demonstrate that even with highly flexible activities, it is difficult to schedule demand greater than 60 percent of resources without the use of optimization and conflict resolution capabilities in the scheduling system.

  2. Bouts of Responding: The Relation between Bout Rate and the Rate of Variable-Interval Reinforcement

    ERIC Educational Resources Information Center

    Shull, Richard L.; Grimes, Julie A.; Bennett, J. Adam

    2004-01-01

    By nose poking a lighted key, rats obtained food pellets on either a variable- interval schedule of reinforcement or a schedule that required an average of four additional responses after the end of the variable-interval component (a tandem variable-interval variable-ratio 4 schedule). With both schedule types, the mean variable interval was…

  3. Comparison of High-Intensity Interval Training and Moderate-to-Vigorous Continuous Training for Cardiometabolic Health and Exercise Enjoyment in Obese Young Women: A Randomized Controlled Trial

    PubMed Central

    Sun, Shengyan; Song, Lili; Shi, Qingde

    2016-01-01

    Objective The aim of this study was to compare the effects of 5-week high-intensity interval training (HIIT) and moderate-to-vigorous intensity continuous training (MVCT) on cardiometabolic health outcomes and enjoyment of exercise in obese young women. Methods A randomized controlled experiment was conducted that involved thirty-one obese females (age range of 18–30) randomly assigned to either HIIT or MVCT five-week training programs. Participants in HIIT condition performed 20 min of repeated 8 s cycling interspersed with 12 s rest intervals, and those in MVCT condition cycled continuously for 40 min at 60–80% of peak oxygen consumption (V˙O2peak), both for four days in a week. Outcomes such as V˙O2peak, body composition estimated by bioimpedance analysis, blood lipids, and serum sexual hormones were measured at pre-and post-training. The scores of Physical Activity Enjoyment Scale (PAES) were collected during the intervention. Results After training, V˙O2peak increased significantly for both training programs (9.1% in HIIT and 10.3% in MVCT) (p = 0.010, η2 = 0.41). Although MVCT group had a significant reduction in total body weight (TBW, −1.8%, p = 0.034), fat mass (FM, - 4.7%, p = 0.002) and percentage body fat (PBF, −2.9%, p = 0.016), there were no significant between-group differences in the change of the pre- and post-measures of these variables. The HIIT group had a higher score on PAES than the MVCT group during the intervention. For both conditions, exercise training led to a decline in resting testosterone and estradiol levels, but had no significant effect on blood lipids. Conclusion Both HIIT and MVCT are effective in improving cardiorespiratory fitness and in reducing sexual hormones in obese young women; however, HIIT is a more enjoyable and time-efficient strategy. The mild-HIIT protocol seems to be useful for at least maintaining the body weight among sedentary individuals. PMID:27368057

  4. Distribution of transition times in a stochastic model of excitable cell: Insights into the cell-intrinsic mechanisms of randomness in neuronal interspike intervals

    NASA Astrophysics Data System (ADS)

    Requena-Carrión, Jesús; Requena-Carrión, Víctor J.

    2016-04-01

    In this paper, we develop an analytical approach to studying random patterns of activity in excitable cells. Our analytical approach uses a two-state stochastic model of excitable system based on the electrophysiological properties of refractoriness and restitution, which characterize cell recovery after excitation. By applying the notion of probability density flux, we derive the distributions of transition times between states and the distribution of interspike interval (ISI) durations for a constant applied stimulus. The derived ISI distribution is unimodal and, provided that the time spent in the excited state is constant, can be approximated by a Rayleigh peak followed by an exponential tail. We then explore the role of the model parameters in determining the shape of the derived distributions and the ISI coefficient of variation. Finally, we use our analytical results to study simulation results from the stochastic Morris-Lecar neuron and from a three-state extension of the proposed stochastic model, which is capable of reproducing multimodal ISI histograms.

  5. Design and rationale of the HITTS randomized controlled trial: Effect of High-intensity Interval Training in de novo Heart Transplant Recipients in Scandinavia.

    PubMed

    Nytrøen, Kari; Yardley, Marianne; Rolid, Katrine; Bjørkelund, Elisabeth; Karason, Kristjan; Wigh, Julia Philip; Dall, Christian Have; Arora, Satish; Aakhus, Svend; Lunde, Ketil; Solberg, Ole Geir; Gustafsson, Finn; Prescott, Eva Irene Bossano; Gullestad, Lars

    2016-02-01

    There is no consensus on how, when, and at what intensity exercise should be performed and organized after heart transplantation (HTx). Most rehabilitation programs are conducted in HTx centers, which might be impractical and costly. We have recently shown that high-intensity interval training (HIT) is safe, well tolerated, and efficacious in maintenance HTx recipients, but there are no studies among de novo patients, and whether HIT is feasible and superior to moderate training in HTx recipients is unclear. A total of 120 clinically stable HTx recipients older than 18 years will be recruited from 3 Scandinavian HTx centers. Participants are randomized to HIT or moderate training, shortly after surgery. All exercises are supervised in the patients' local communities. Testing at baseline and follow-up includes the following: VO2peak (primary end point), muscle strength, body composition, quality of life, myocardial performance, endothelial function, biomarkers, and progression of cardiac allograft vasculopathy. A subgroup (n = 90) will also be tested at 3-year follow-up to assess long-term effects of exercise. So far, the HIT intervention is well tolerated, without any serious adverse events. We aim to test whether decentralized HIT is feasible, safe, and superior to moderate training, and whether it will lead to significant improvement in exercise capacity and less long-term complications. PMID:26856221

  6. Prospective Randomized Controlled Study on the Efficacy of Multimedia Informed Consent for Patients Scheduled to Undergo Green-Light High-Performance System Photoselective Vaporization of the Prostate

    PubMed Central

    Ham, Dong Yeub; Choi, Woo Suk; Song, Sang Hoon; Ahn, Young-Joon; Park, Hyoung Keun; Kim, Hyeong Gon

    2016-01-01

    Purpose The aim of this study was to evaluate the efficacy of a multimedia informed consent (IC) presentation on the understanding and satisfaction of patients who were scheduled to receive 120-W green-light high-performance system photoselective vaporization of the prostate (HPS-PVP). Materials and Methods A multimedia IC (M-IC) presentation for HPS-PVP was developed. Forty men with benign prostatic hyperplasia who were scheduled to undergo HPS-PVP were prospectively randomized to a conventional written IC group (W-IC group, n=20) or the M-IC group (n=20). The allocated IC was obtained by one certified urologist, followed by a 15-question test (maximum score, 15) to evaluate objective understanding, and questionnaires on subjective understanding (range, 0~10) and satisfaction (range, 0~10) using a visual analogue scale. Results Demographic characteristics, including age and the highest level of education, did not significantly differ between the two groups. No significant differences were found in scores reflecting the objective understanding of HPS-PVP (9.9±2.3 vs. 10.6±2.8, p=0.332) or in subjective understanding scores (7.5±2.1 vs. 8.6±1.7, p=0.122); however, the M-IC group showed higher satisfaction scores than the W-IC group (7.4±1.7 vs. 8.4±1.5, p=0.033). After adjusting for age and educational level, the M-IC group still had significantly higher satisfaction scores. Conclusions M-IC did not enhance the objective knowledge of patients regarding this surgical procedure. However, it improved the satisfaction of patients with the IC process itself. PMID:27169129

  7. A Randomized, Controlled Trial of the Impact of Alternative Dosing Schedules on the Immune Response to Human Rotavirus Vaccine in Rural Ghanaian Infants

    PubMed Central

    Armah, George; Lewis, Kristen D. C.; Cortese, Margaret M.; Parashar, Umesh D.; Ansah, Akosua; Gazley, Lauren; Victor, John C.; McNeal, Monica M.; Binka, Fred; Steele, A. Duncan

    2016-01-01

    Background. The recommended schedule for receipt of 2-dose human rotavirus vaccine (HRV) coincides with receipt of the first and second doses of diphtheria, pertussis, and tetanus vaccine (ie, 6 and 10 weeks of age, respectively). Alternative schedules and additional doses of HRV have been proposed and may improve vaccine performance in low-income countries. Methods. In this randomized trial in rural Ghana, HRV was administered at ages 6 and 10 weeks (group 1), 10 and 14 weeks (group 2), or 6, 10, and 14 weeks (group 3). We compared serum antirotavirus immunoglobulin A (IgA) seroconversion (≥20 U/mL) and geometric mean concentrations (GMCs) between group 1 and groups 2 and 3. Results. Ninety-three percent of participants (424 of 456) completed the study per protocol. In groups 1, 2, and 3, the IgA seroconversion frequencies among participants with IgA levels of <20 U/mL at baseline were 28.9%, 37.4%, and 43.4%, respectively (group 1 vs group 3, P = .014; group 1 vs group 2, P = .163). Postvaccination IgA GMCs were 22.1 U/mL, 26.5 U/mL, and 32.6 U/mL in groups 1, 2, and 3, respectively (group 1 vs group 3, P = .038; group 1 vs group 2, P = .304). Conclusions. A third dose of HRV resulted in increased seroconversion frequencies and GMCs, compared with 2 doses administered at 6 and 10 weeks of age. Since there is no correlate of protection, a postmarketing effectiveness study is required to determine whether the improvement in immune response translates into a public health benefit in low-income countries. Clinical Trials Registration. NCT015751. PMID:26823335

  8. Effects of Home-Based Interval Walking Training on Thigh Muscle Strength and Aerobic Capacity in Female Total Hip Arthroplasty Patients: A Randomized, Controlled Pilot Study

    PubMed Central

    Morishima, Yutaka; Mizushima, Takashi; Yamauchi, Katsuya; Morikawa, Mayuko; Masuki, Shizue; Nose, Hiroshi

    2014-01-01

    Due to the reduced physical activity of patients who have undergone total hip arthroplasty (THA), there are no home-based exercise training regimens for preventing muscle atrophy and aerobic capacity impairment in these patients. We examined whether interval walking training (IWT) could prevented these issues. Twenty-eight female patients (∼60 years of age) who had undergone THA more than 2 months prior were randomly divided into IWT (n = 14) and control (CNT, n = 14) groups. The IWT subjects trained at a target of 60 min of fast walking at >70% peak aerobic capacity for walking (O2peak) per wk for 12 wk, while those in the CNT maintained their previous sedentary life during the same period. We measured the energy expenditure of the daily physical activity, except during sleeping and bathing, every minute and every day during the intervention. We also measured the isometric knee extension (FEXT) and flexion (FFLX) forces, O2peak, and anaerobic threshold during the graded cycling exercise (O2AT) before and after the intervention. All subjects, except for one in IWT, completed the protocol. FFLX increased by 23% on the operated side (P = 0.003) and 14% on the non-operated side of IWT (P = 0.006), while it only increased on the operated side of CNT (P = 0.03). The O2peak and O2AT in IWT increased by 8% (P = 0.08) and 13% (P = 0.002), respectively, and these changes were significantly higher in the IWT than in CNT group (both, P<0.05). In conclusion, IWT might be an effective home-based training regimen for preventing the muscle atrophy from reduced daily physical activity in THA patients. Trial Registration UMIN-CTR UMIN000013172 PMID:25268505

  9. Interval Training.

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports, Washington, DC.

    Regardless of the type of physical activity used, interval training is simply repeated periods of physical stress interspersed with recovery periods during which activity of a reduced intensity is performed. During the recovery periods, the individual usually keeps moving and does not completely recover before the next exercise interval (e.g.,…

  10. Interbirth intervals

    PubMed Central

    Haig, David

    2014-01-01

    Background and objectives: Interbirth intervals (IBIs) mediate a trade-off between child number and child survival. Life history theory predicts that the evolutionarily optimal IBI differs for different individuals whose fitness is affected by how closely a mother spaces her children. The objective of the article is to clarify these conflicts and explore their implications for public health. Methodology: Simple models of inclusive fitness and kin conflict address the evolution of human birth-spacing. Results: Genes of infants generally favor longer intervals than genes of mothers, and infant genes of paternal origin generally favor longer IBIs than genes of maternal origin. Conclusions and implications: The colonization of maternal bodies by offspring cells (fetal microchimerism) raises the possibility that cells of older offspring could extend IBIs by interfering with the implantation of subsequent embryos. PMID:24480612

  11. Procrastination by pigeons with fixed-interval response requirements.

    PubMed

    Mazur, J E

    1998-03-01

    Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230

  12. Procrastination by pigeons with fixed-interval response requirements.

    PubMed Central

    Mazur, J E

    1998-01-01

    Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230

  13. Scheduling game

    SciTech Connect

    Kleck, W

    1982-04-01

    Structuring a schedule - whether by Critical Path Method (CPM) or Precedence Charting System (PCS) - involves estimating the duration of one or more activities and arranging them in the most logical sequence. Given the start date, the completion date is relatively simple to determine. What is then so complicated about the process. It is complicated by the people involved - the people who make the schedules and the people who attempt to follow them. Schedules are an essential part of project management and construction contract administration. Much of the material available pertains to the mechanics of schedules, the types of logic networks, the ways that data can be generated and presented. This paper sheds light on other facets of the subject - the statistical and philosophical fundamentals involved in scheduling.

  14. Interval training based on ventilatory anaerobic threshold increases cardiac vagal modulation and decreases high-sensitivity c-reative protein: randomized clinical trial in coronary artery disease

    PubMed Central

    Tamburus, Nayara Y.; Paula, Roberta F. L.; Kunz, Vandeni C.; César, Marcelo C.; Moreno, Marlene A.; da Silva, Ester

    2015-01-01

    Background: Autonomic dysfunction and inflammatory activity are involved in the development and progression of coronary artery disease (CAD), and exercise training has been shown to confer a cardiovascular benefit. Objective: To evaluate the effects that interval training (IT) based on ventilatory anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as the relationship between both levels, in patients with CAD and/or cardiovascular risk factors (RF). Method: Forty-two men (aged 57.88±6.20 years) were divided into two training groups, CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C (n=10). Heart rate and RR intervals in the supine position, cardiopulmonary exercise tests, and hs-CRP levels were measured before and after IT. HRV was analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week IT program of three weekly sessions at training intensities based on the VAT. Results: In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased (p<0.02), while cardiac parasympathetic modulation index increased (p<0.02). In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP, systolic, and diastolic blood pressures decreased (p<0.02). Both control groups showed increase in hs-CRP parameters (p<0.02). There was a strong and significant association between parasympathetic and sympathetic modulations with hs-CRP. Conclusion: The IT program based on the VAT promoted a decrease in hs-CRP associated with improvement in cardiac autonomic modulation. PMID:26647745

  15. Response Strength in Extreme Multiple Schedules

    PubMed Central

    McLean, Anthony P; Grace, Randolph C; Nevin, John A

    2012-01-01

    Four pigeons were trained in a series of two-component multiple schedules. Reinforcers were scheduled with random-interval schedules. The ratio of arranged reinforcer rates in the two components was varied over 4 log units, a much wider range than previously studied. When performance appeared stable, prefeeding tests were conducted to assess resistance to change. Contrary to the generalized matching law, logarithms of response ratios in the two components were not a linear function of log reinforcer ratios, implying a failure of parameter invariance. Over a 2 log unit range, the function appeared linear and indicated undermatching, but in conditions with more extreme reinforcer ratios, approximate matching was observed. A model suggested by McLean (1991), originally for local contrast, predicts these changes in sensitivity to reinforcer ratios somewhat better than models by Herrnstein (1970) and by Williams and Wixted (1986). Prefeeding tests of resistance to change were conducted at each reinforcer ratio, and relative resistance to change was also a nonlinear function of log reinforcer ratios, again contrary to conclusions from previous work. Instead, the function suggests that resistance to change in a component may be determined partly by the rate of reinforcement and partly by the ratio of reinforcers to responses. PMID:22287804

  16. Mission scheduling

    NASA Technical Reports Server (NTRS)

    Gaspin, Christine

    1989-01-01

    How a neural network can work, compared to a hybrid system based on an operations research and artificial intelligence approach, is investigated through a mission scheduling problem. The characteristic features of each system are discussed.

  17. Effect of initial seed and number of samples on simple-random and Latin-Hypercube Monte Carlo probabilities (confidence interval considerations)

    SciTech Connect

    ROMERO,VICENTE J.

    2000-05-04

    In order to devise an algorithm for autonomously terminating Monte Carlo sampling when sufficiently small and reliable confidence intervals (CI) are achieved on calculated probabilities, the behavior of CI estimators must be characterized. This knowledge is also required in comparing the accuracy of other probability estimation techniques to Monte Carlo results. Based on 100 trials in a hypothesis test, estimated 95% CI from classical approximate CI theory are empirically examined to determine if they behave as true 95% CI over spectrums of probabilities (population proportions) ranging from 0.001 to 0.99 in a test problem. Tests are conducted for population sizes of 500 and 10,000 samples where applicable. Significant differences between true and estimated 95% CI are found to occur at probabilities between 0.1 and 0.9, such that estimated 95% CI can be rejected as not being true 95% CI at less than a 40% chance of incorrect rejection. With regard to Latin Hypercube sampling (LHS), though no general theory has been verified for accurately estimating LHS CI, recent numerical experiments on the test problem have found LHS to be conservatively over an order of magnitude more efficient than SRS for similar sized CI on probabilities ranging between 0.25 and 0.75. The efficiency advantage of LHS vanishes, however, as the probability extremes of 0 and 1 are approached.

  18. Capacitated max -Batching with Interval Graph Compatibilities

    NASA Astrophysics Data System (ADS)

    Nonner, Tim

    We consider the problem of partitioning interval graphs into cliques of bounded size. Each interval has a weight, and the weight of a clique is the maximum weight of any interval in the clique. This natural graph problem can be interpreted as a batch scheduling problem. Solving a long-standing open problem, we show NP-hardness, even if the bound on the clique sizes is constant. Moreover, we give a PTAS based on a novel dynamic programming technique for this case.

  19. Effect of 24 Sessions of High-Intensity Aerobic Interval Training Carried out at Either High or Moderate Frequency, a Randomized Trial

    PubMed Central

    Hatle, Håvard; Støbakk, Per Kristian; Mølmen, Harald Edvard; Brønstad, Eivind; Tjønna, Arnt Erik; Steinshamn, Sigurd; Skogvoll, Eirik; Wisløff, Ulrik; Ingul, Charlotte Björk; Rognmo, Øivind

    2014-01-01

    Purpose The training response of an intensified period of high-intensity exercise is not clear. Therefore, we compared the cardiovascular adaptations of completing 24 high-intensity aerobic interval training sessions carried out for either three or eight weeks, respectively. Methods Twenty-one healthy subjects (23.0±2.1 years, 10 females) completed 24 high-intensity training sessions throughout a time-period of either eight weeks (moderate frequency, MF) or three weeks (high frequency, HF) followed by a detraining period of nine weeks without any training. In both groups, maximal oxygen uptake (VO2max) was evaluated before training, at the 9th and 17th session and four days after the final 24th training session. In the detraining phase VO2max was evaluated after 12 days and thereafter every second week for eight weeks. Left ventricular echocardiography, carbon monoxide lung diffusion transfer factor, brachial artery flow mediated dilatation and vastus lateralis citrate maximal synthase activity was tested before and after training. Results The cardiovascular adaptation after HF training was delayed compared to training with MF. Four days after ending training the HF group showed no improvement (+3.0%, p = 0.126), whereas the MF group reached their highest VO2max with a 10.7% improvement (p<0.001: group difference p = 0.035). The HF group reached their highest VO2max (6.1% increase, p = 0.026) twelve days into the detraining period, compared to a concomitant reduction to 7.9% of VO2max (p<0.001) above baseline in the MF group (group difference p = 0.609). Conclusion Both HF and MF training of high-intensity aerobic exercise improves VO2max. The cardiovascular adaptation following a HF programme of high-intensity exercise is however delayed compared to MF training. Trial Registration ClinicalTrials.gov NCT00733941. PMID:24516645

  20. Modified high-intensity interval training reduces liver fat and improves cardiac function in non-alcoholic fatty liver disease: a randomized controlled trial.

    PubMed

    Hallsworth, Kate; Thoma, Christian; Hollingsworth, Kieren G; Cassidy, Sophie; Anstee, Quentin M; Day, Christopher P; Trenell, Michael I

    2015-12-01

    Although lifestyle changes encompassing weight loss and exercise remain the cornerstone of non-alcoholic fatty liver disease (NAFLD) management, the effect of different types of exercise on NAFLD is unknown. This study defines the effect of modified high-intensity interval training (HIIT) on liver fat, cardiac function and metabolic control in adults with NAFLD. Twenty-three patients with NAFLD [age 54±10 years, body mass index (BMI) 31±4 kg/m(2), intra-hepatic lipid >5%) were assigned to either 12 weeks HIIT or standard care (controls). HIIT involved thrice weekly cycle ergometry for 30-40 min. MRI and spectroscopy were used to assess liver fat, abdominal fat and cardiac structure/function/energetics. Glucose control was assessed by oral glucose tolerance test and body composition by air displacement plethysmography. Relative to control, HIIT decreased liver fat (11±5% to 8±2% compared with 10±4% to 10±4% P=0.019), whole-body fat mass (35±7 kg to 33±8 kg compared with 31±9 kg to 32±9 kg, P=0.013), alanine (52±29 units/l to 42±20 units/l compared with 47±22 units/l to 51±24 units/l, P=0.016) and aspartate aminotransferase (AST; 36±18 units/l to 33±15 units/l compared with 31±8 units/l to 35±8 units/l, P=0.017) and increased early diastolic filling rate (244±84 ml/s to 302±107 ml/s compared with 255±82 ml/s to 251±82 ml/s, P=0.018). There were no between groups differences in glucose control. Modified HIIT reduces liver fat and improves body composition alongside benefits to cardiac function in patients with NAFLD and should be considered as part of the broader treatment regimen by clinical care teams. ISRCTN trial ID: ISRCTN78698481. PMID:26265792

  1. Effects of Sprint versus High-Intensity Aerobic Interval Training on Cross-Country Mountain Biking Performance: A Randomized Controlled Trial

    PubMed Central

    Inoue, Allan; Impellizzeri, Franco M.; Pires, Flávio O.; Pompeu, Fernando A. M. S.; Deslandes, Andrea C.; Santos, Tony M.

    2016-01-01

    Objectives The current study compared the effects of high-intensity aerobic training (HIT) and sprint interval training (SIT) on mountain biking (MTB) race simulation performance and physiological variables, including peak power output (PPO), lactate threshold (LT) and onset of blood lactate accumulation (OBLA). Methods Sixteen mountain bikers (mean ± SD: age 32.1 ± 6.4 yr, body mass 69.2 ± 5.3 kg and VO2max 63.4 ± 4.5 mL∙kg-1∙min-1) completed graded exercise and MTB performance tests before and after six weeks of training. The HIT (7–10 x [4–6 min—highest sustainable intensity / 4–6 min—CR100 10–15]) and SIT (8–12 x [30 s—all-out intensity / 4 min—CR100 10–15]) protocols were included in the participants’ regular training programs three times per week. Results Post-training analysis showed no significant differences between training modalities (HIT vs. SIT) in body mass, PPO, LT or OBLA (p = 0.30 to 0.94). The Cohen’s d effect size (ES) showed trivial to small effects on group factor (p = 0.00 to 0.56). The interaction between MTB race time and training modality was almost significant (p = 0.08), with a smaller ES in HIT vs. SIT training (ES = -0.43). A time main effect (pre- vs. post-phases) was observed in MTB race performance and in several physiological variables (p = 0.001 to 0.046). Co-variance analysis revealed that the HIT (p = 0.043) group had significantly better MTB race performance measures than the SIT group. Furthermore, magnitude-based inferences showed HIT to be of likely greater benefit (83.5%) with a lower probability of harmful effects (0.8%) compared to SIT. Conclusion The results of the current study suggest that six weeks of either HIT or SIT may be effective at increasing MTB race performance; however, HIT may be a preferable strategy. Trial Registration ClinicalTrials.gov NCT01944865 PMID:26789124

  2. Exact Statistics of the Gap and Time Interval between the First Two Maxima of Random Walks and Lévy Flights

    NASA Astrophysics Data System (ADS)

    Majumdar, Satya N.; Mounaix, Philippe; Schehr, Grégory

    2013-08-01

    We investigate the statistics of the gap Gn between the two rightmost positions of a Markovian one-dimensional random walker (RW) after n time steps and of the duration Ln which separates the occurrence of these two extremal positions. The distribution of the jumps ηi’s of the RW, f(η), is symmetric and its Fourier transform has the small k behavior 1-f^(k)˜|k|μ, with 0<μ≤2. For μ=2, the RW converges, for large n, to Brownian motion, while for 0<μ<2 it corresponds to a Lévy flight of index μ. We compute the joint probability density function (PDF) Pn(g,l) of Gn and Ln and show that, when n→∞, it approaches a limiting PDF p(g,l). The corresponding marginal PDFs of the gap, pgap(g), and of Ln, ptime(l), are found to behave like pgap(g)˜g-1-μ for g≫1 and 0<μ<2, and ptime(l)˜l-γ(μ) for l≫1 with γ(1<μ≤2)=1+1/μ and γ(0<μ<1)=2. For l, g≫1 with fixed lg-μ, p(g,l) takes the scaling form p(g,l)˜g-1-2μp˜μ(lg-μ), where p˜μ(y) is a (μ-dependent) scaling function. We also present numerical simulations which verify our analytic results.

  3. Exact statistics of the gap and time interval between the first two maxima of random walks and Lévy flights.

    PubMed

    Majumdar, Satya N; Mounaix, Philippe; Schehr, Grégory

    2013-08-16

    We investigate the statistics of the gap G(n) between the two rightmost positions of a Markovian one-dimensional random walker (RW) after n time steps and of the duration L(n) which separates the occurrence of these two extremal positions. The distribution of the jumps η(i)'s of the RW, f(η), is symmetric and its Fourier transform has the small k behavior 1-f[over ^](k)~|k|(μ), with 0<μ≤2. For μ=2, the RW converges, for large n, to Brownian motion, while for 0<μ<2 it corresponds to a Lévy flight of index μ. We compute the joint probability density function (PDF) P(n)(g,l) of G(n) and L(n) and show that, when n→∞, it approaches a limiting PDF p(g,l). The corresponding marginal PDFs of the gap, p(gap)(g), and of L(n), p(time)(l), are found to behave like p(gap)(g)~g(-1-μ) for g>1 and 0<μ<2, and p(time)(l)~l(-γ(μ)) for l>1 with γ(1<μ≤2)=1+1/μ and γ(0<μ<1)=2. For l, g>1 with fixed lg(-μ), p(g,l) takes the scaling form p(g,l)~g(-1-2μ)p[over ˜](μ)(lg(-μ)), where p[over ˜](μ)(y) is a (μ-dependent) scaling function. We also present numerical simulations which verify our analytic results. PMID:23992054

  4. Discrimination of Variable Schedules Is Controlled by Interresponse Times Proximal to Reinforcement

    ERIC Educational Resources Information Center

    Tanno, Takayuki; Silberberg, Alan; Sakagami, Takayuki

    2012-01-01

    In Experiment 1, food-deprived rats responded to one of two schedules that were, with equal probability, associated with a sample lever. One schedule was always variable ratio, while the other schedule, depending on the trial within a session, was: (a) a variable-interval schedule; (b) a tandem variable-interval,…

  5. Familiarity-Frequency Ratings of Melodic Intervals

    ERIC Educational Resources Information Center

    Jeffries, Thomas B.

    1972-01-01

    Objective of this study was to determine subjects' reliability in rating randomly played ascending and descending melodic intervals within the octave on the basis of their familiarity with each type of interval and the frequency of their having experienced each type of interval in music. (Author/CB)

  6. Resistance to Extinction Following Variable-Interval Reinforcement: Reinforcer Rate and Amount

    ERIC Educational Resources Information Center

    Shull, Richard L.; Grimes, Julie A.

    2006-01-01

    Rats obtained food-pellet reinforcers by nose poking a lighted key. Experiment 1 examined resistance to extinction following single-schedule training with different variable-interval schedules, ranging from a mean interval of 16 min to 0.25 min. That is, for each schedule, the rats received 20 consecutive daily baseline sessions and then a session…

  7. Trabectedin plus pegylated liposomal doxorubicin in relapsed ovarian cancer: outcomes in the partially platinum-sensitive (platinum-free interval 6–12 months) subpopulation of OVA-301 phase III randomized trial

    PubMed Central

    Poveda, A.; Vergote, I.; Tjulandin, S.; Kong, B.; Roy, M.; Chan, S.; Filipczyk-Cisarz, E.; Hagberg, H.; Kaye, S. B.; Colombo, N.; Lebedinsky, C.; Parekh, T.; Gómez, J.; Park, Y. C.; Alfaro, V.; Monk, B. J.

    2011-01-01

    Background: OVA-301 is a large randomized trial that showed superiority of trabectedin plus pegylated liposomal doxorubicin (PLD) over PLD alone in relapsed ovarian cancer. The optimal management of patients with partially platinum-sensitive relapse [6–12 months platinum-free interval (PFI)] is unclear. Patients and methods: Within OVA-301, we therefore now report on the outcomes for the 214 cases in this subgroup. Results: Trabectedin/PLD resulted in a 35% risk reduction of disease progression (DP) or death [hazard ratio (HR) = 0.65, 95% confidence interval (CI), 0.45–0.92; P = 0.0152; median progression-free survival (PFS) 7.4 versus 5.5 months], and a significant 41% decrease in the risk of death (HR = 0.59; 95% CI, 0.43–0.82; P = 0.0015; median survival 23.0 versus 17.1 months). The safety of trabectedin/PLD in this subset mimicked that of the overall population. Similar proportions of patients received subsequent therapy in each arm (76% versus 77%), although patients in the trabectedin/PLD arm had a slightly lower proportion of further platinum (49% versus 55%). Importantly, patients in the trabectedin/PLD arm survived significantly longer after subsequent platinum (HR = 0.63; P = 0.0357; median 13.3 versus 9.8 months). Conclusion: This hypothesis-generating analysis demonstrates that superior benefits with trabectedin/PLD in terms of PFS and survival in the overall population appear particularly enhanced in patients with partially sensitive disease (PFI 6–12 months). PMID:20643862

  8. ASTER Scheduling Prioritization Function

    NASA Technical Reports Server (NTRS)

    Cohen, Ron

    1996-01-01

    ASTER schedules are generated by an automated scheduling system. This scheduler will generate psuedo-optimal schedules based on a priority scheme. This priority scheme is controlled by the Science Team.

  9. Non-clairvoyant Scheduling Games

    NASA Astrophysics Data System (ADS)

    Dürr, Christoph; Nguyen, Kim Thang

    In a scheduling game, each player owns a job and chooses a machine to execute it. While the social cost is the maximal load over all machines (makespan), the cost (disutility) of each player is the completion time of its own job. In the game, players may follow selfish strategies to optimize their cost and therefore their behaviors do not necessarily lead the game to an equilibrium. Even in the case there is an equilibrium, its makespan might be much larger than the social optimum, and this inefficiency is measured by the price of anarchy - the worst ratio between the makespan of an equilibrium and the optimum. Coordination mechanisms aim to reduce the price of anarchy by designing scheduling policies that specify how jobs assigned to a same machine are to be scheduled. Typically these policies define the schedule according to the processing times as announced by the jobs. One could wonder if there are policies that do not require this knowledge, and still provide a good price of anarchy. This would make the processing times be private information and avoid the problem of truthfulness. In this paper we study these so-called non-clairvoyant policies. In particular, we study the RANDOM policy that schedules the jobs in a random order without preemption, and the EQUI policy that schedules the jobs in parallel using time-multiplexing, assigning each job an equal fraction of CPU time.

  10. Interval estimates and their precision

    NASA Astrophysics Data System (ADS)

    Marek, Luboš; Vrabec, Michal

    2015-06-01

    A task very often met in in practice is computation of confidence interval bounds for the relative frequency within sampling without replacement. A typical situation includes preelection estimates and similar tasks. In other words, we build the confidence interval for the parameter value M in the parent population of size N on the basis of a random sample of size n. There are many ways to build this interval. We can use a normal or binomial approximation. More accurate values can be looked up in tables. We consider one more method, based on MS Excel calculations. In our paper we compare these different methods for specific values of M and we discuss when the considered methods are suitable. The aim of the article is not a publication of new theoretical methods. This article aims to show that there is a very simple way how to compute the confidence interval bounds without approximations, without tables and without other software costs.

  11. The Effects of Interval Duration on Temporal Tracking and Alternation Learning

    ERIC Educational Resources Information Center

    Ludvig, Elliot A.; Staddon, John E. R.

    2005-01-01

    On cyclic-interval reinforcement schedules, animals typically show a postreinforcement pause that is a function of the immediately preceding time interval ("temporal tracking"). Animals, however, do not track single-alternation schedules--when two different intervals are presented in strict alternation on successive trials. In this experiment,…

  12. Prospective randomized study of various irradiation doses and fractionation schedules in the treatment of inoperable non-oat-cell carcinoma of the lung

    SciTech Connect

    Perez, C.A.; Stanley, K.; Rubin, P.; Kramer, S.; Brady, L.; Perez-Tamayo, R.; Brown, G.S.; Concannon, J.; Rotman, M.; Seydel, H.G.

    1980-06-01

    Analysis is presented of a prospective randomized study involving 365 patients with histologically proven unresectable non-oat-cell carcinoma of the lung treated with deffinitive radiotherapy. The patients were radomized to one of four treatment regimens: 4000 rad split course, or 4000, 5000, or 6000-rad continuous courses in five fractions per week. Ninety to 100 patients were accessioned to each group. The one-year survival rate is 50% and the two-year survival rate, 25%. The patients treated with the split course have the lowest survival rate in comparison with the other groups. The complete and partial local regression of tumor was 49% in patients treated with 4000 rad and 55% in the groups treated with 5000 and 6000 rad. For patients who achieved complete regression of the tumor following irradiation, the two-year survival rate is 40%, in contrast to 20% for those with partial regression, and no survivors among the patients with stable or progressive disease. The incidence of intrathoracic recurrence was 33% for patients treated with 6000 rad, 39% for those receiving 5000 rad, and 44 to 49% for those treated with a 4000-rad split or continuous course. At present, the data stongly suggest that patients treated with 5000 or 6000 rad have a better response, tumor control, and survival rate than those receiving lower doses. Patients with high performance status or with tumors in earlier stages have a two-year survival rate of approx. 40%, in comparison with 20% for other patients. The various irradiation regimens have been well tolerated, with complications being slightly higher in the 4000-rad split course group and in the 6000-rad continuous course group. The most frequent complications have been pneumonitis, pulmonary fibrosis, and dyspagia due to transient esophagitis. Further investigation will be necessary before the optimal management of patients with bronchogenic carcinoma by irradiation is established.

  13. Randomized, double-blind, active-controlled study evaluating the safety and immunogenicity of three vaccination schedules and two dose levels of AV7909 vaccine for anthrax post-exposure prophylaxis in healthy adults.

    PubMed

    Hopkins, Robert J; Kalsi, Gurdyal; Montalvo-Lugo, Victor M; Sharma, Mona; Wu, Yukun; Muse, Derek D; Sheldon, Eric A; Hampel, Frank C; Lemiale, Laurence

    2016-04-19

    AV7909 vaccine being developed for post-exposure prophylaxis of anthrax disease may require fewer vaccinations and reduced amount of antigen to achieve an accelerated immune response over BioThrax(®) (Anthrax Vaccine Adsorbed). A phase 2, randomized, double-blind, BioThrax vacccine-controlled study was conducted to evaluate the safety and immunogenicity of three intramuscular vaccination schedules and two dose levels of AV7909 in 168 healthy adults. Subjects were randomized at a 4:3:2:4:2 ratio to 5 groups: (1) AV7909 on Days 0/14; (2) AV7909 on Days 0/28; (3) AV7909 on Days 0/14/28; (4) half dose AV7909 on Days 0/14/28; and (5) BioThrax vaccine on Days 0/14/28. Vaccinations in all groups were well tolerated. The incidences of adverse events (AEs) were 79% for AV7909 subjects and 65% for BioThrax subjects; 92% of AV7909 subjects and 87% of BioThrax subjects having AEs reported Grade 1-2 AEs. No serious AEs were assessed as potentially vaccine-related, and no AEs of potential autoimmune etiology were reported. There was no discernible pattern indicative of a safety concern across groups in the incidence or severity of reactogenicity events. Groups 2-4 achieved success for the primary endpoint, demonstrated by a lower 95% confidence limit of the percentage of subjects with protective toxin neutralizing antibody NF50 values (≥0.56) to be ≥40% at Day 63. Group 1 marginally missed the criterion (lower bound 95% confidence limit of 39.5%). Immune responses were above this threshold for Groups 1, 3 and 4 at Day 28 and all groups at Day 42. Further study of an AV7909 two-dose schedule given 2 weeks apart is warranted in light of the favorable tolerability profile and immunogenicity response relative to three doses of BioThrax vaccine, as well as preliminary data from nonclinical studies indicating similar immune responses correlate with higher survival for AV7909 than BioThrax vaccine. PMID:26979136

  14. Schedule shifts, cancer and longevity

    PubMed Central

    Cornélissen, Germaine; Halberg, Julia; Halberg, Franz; de la Pena, Salvador Sanchez; Nelson, Walter; Schwartzkopff, Othild; Stoynev, Alexander; Haus, Erhard

    2008-01-01

    Prompted by a recent report of the possible carcinogenic effect of shiftwork focusing on the disruption of circadian rhythms, we review studies involving shifts in schedule implemented at varying intervals in unicells, insects and mammals, including humans. Results indicate the desirability to account for a broader-than-circadian view. They also suggest the possibility of optimizing schedule shifts by selecting intervals between consecutive shifts associated with potential side-effects such as an increase in cancer risk. Toward this goal, marker rhythmometry is most desirable. The monitoring of blood pressure and heart rate present the added benefit of assessing cardiovascular disease risks resulting not only from an elevated blood pressure but also from abnormal variability in blood pressure and/or heart rate of normotensive as well as hypertensive subjects. PMID:19227006

  15. A multicentric randomized controlled trial on the impact of lengthening the interval between neoadjuvant radiochemotherapy and surgery on complete pathological response in rectal cancer (GRECCAR-6 trial): rationale and design

    PubMed Central

    2013-01-01

    Background Neoadjuvant radiochemotherapy (RCT) is now part of the armamentarium of cancer of the lower and middle rectum. It is recommended in current clinical practice prior to surgical excision if the lesion is classified T3/T4 or N+. Histological complete response, defined by the absence of persistent tumor cell invasion and lymph node (ypT0N0) after pathological examination of surgical specimen has been shown to be an independent prognostic factor of overall survival and disease-free survival. Surgical excision is usually performed between 6 and 8 weeks after completion of CRT and pathological complete response rate ranges around 12%. In retrospective studies, a lengthening of the interval after RCT beyond 10 weeks was found as an independent factor increasing the rate of pathological complete response (between 26% and 31%), with a longer disease-free survival and without increasing the operative morbidity. The aim of the present study is to evaluate in 264 patients the rate of pathological complete response rate of rectal cancer after RCT by lengthening the time between RCT and surgery. Methods/design The current study is a multicenter randomized trial in two parallel groups comparing 7 and 11 weeks of delay between the end of RCT and cancer surgery of rectal tumors. At the end of the RCT, surgery is planified and randomization is performed after patient’s written consent for participation. The histological complete response (ypT0N0) will be determined with analysis of the complete residual tumor and double reading by two pathologists blinded of the group of inclusion. Patients will be followed in clinics for 5 years after surgery. Participation in this trial does not change patient’s management in terms of treatment, investigations or visits. Secondary endpoints will include overall and disease free survival, rate of sphincter conservation and quality of mesorectal excision. The number of patients needed is 264. Trial registration Clinical

  16. Effects of d-amphetamine and caffeine on schedule-controlled and schedule-induced responding.

    PubMed Central

    McMillan, D E

    1979-01-01

    The effects of d-amphetamine and caffeine were studied on rates and patterns of lever pressing and schedule-induced licking under fixed-interval schedules of food pellet presentation. In addition, the effects of caffeine were studied on lever pressing and licking under a multiple fixed-ratio fixed-interval schedule. Caffeine reduced mean overall rates of licking at lower doses than it reduced mean overall rates of pressing under the fixed-interval schedules, but the effects of caffeine on both licking and lever pressing depended largely on the control rate of responding. d-Amphetamine reduced mean overall rates of lever pressing and licking at about the same dose, but the effects of d-amphetamine also were a function of the control rate of responding. PMID:512573

  17. Influences on Cocaine Tolerance Assessed under a Multiple Conjunctive Schedule of Reinforcement

    ERIC Educational Resources Information Center

    Yoon, Jin Ho; Branch, Marc N.

    2009-01-01

    Under multiple schedules of reinforcement, previous research has generally observed tolerance to the rate-decreasing effects of cocaine that has been dependent on schedule-parameter size in the context of fixed-ratio (FR) schedules, but not under the context of fixed-interval (FI) schedules of reinforcement. The current experiment examined the…

  18. The Reinforcing Effects of Houselight Illumination during Chained Schedules of Food Presentation

    ERIC Educational Resources Information Center

    Allen, Ron; Kupfer, Jeff; Malagodi, E. F.

    2008-01-01

    Pigeons' keypecking was maintained under two- and three-component chained schedules of food presentation. The component schedules were all fixed-interval schedules of either 1- or 2-min duration. Across conditions the presence of houselight illumination within each component schedule was manipulated. For each pigeon, first-component response rates…

  19. Scheduling Reconsidered (Again!)

    ERIC Educational Resources Information Center

    Hentschke, Guilbert C.; Fowler, William J.

    1974-01-01

    Computer technicians bring to school scheduling a certain naivete regarding the operation of schools. School administrators play a fundamental role of informing technicians about education scheduling needs. (Author)

  20. A note on the path interval distance.

    PubMed

    Coons, Jane Ivy; Rusinko, Joseph

    2016-06-01

    The path interval distance accounts for global congruence between locally incongruent trees. We show that the path interval distance provides a lower bound for the nearest neighbor interchange distance. In contrast to the Robinson-Foulds distance, random pairs of trees are unlikely to be maximally distant from one another under the path interval distance. These features indicate that the path interval distance should play a role in phylogenomics where the comparison of trees on a fixed set of taxa is becoming increasingly important. PMID:27040521

  1. Pitch strength of regular-interval click trains with different length “runs” of regular intervals

    PubMed Central

    Yost, William A.; Mapes-Riordan, Dan; Shofner, William; Dye, Raymond; Sheft, Stanley

    2009-01-01

    Click trains were generated with first- and second-order statistics following Kaernbach and Demany [J. Acoust. Soc. Am. 104, 2298–2306 (1998)]. First-order intervals are between successive clicks, while second-order intervals are those between every other click. Click trains were generated with a repeating alternation of fixed and random intervals which produce a pitch at the reciprocal of the duration of the fixed interval. The intervals were then randomly shuffled and compared to the unshuffled, alternating click trains in pitch-strength comparison experiments. In almost all comparisons for the first-order interval stimuli, the shuffled-interval click trains had a stronger pitch strength than the unshuffled-interval click trains. The shuffled-interval click trains only produced stronger pitches for second-order interval stimuli when the click trains were unfiltered. Several experimental conditions and an analysis of runs of regular and random intervals in these click trains suggest that the auditory system is sensitive to runs of regular intervals in a stimulus that contains a mix of regular and random intervals. These results indicate that fine-structure regularity plays a more important role in pitch perception than randomness, and that the long-term autocorrelation function or spectra of these click trains are not good predictors of pitch strength. PMID:15957774

  2. Randomized phase II study of two schedules of flavopiridol given as timed sequential therapy with cytosine arabinoside and mitoxantrone for adults with newly diagnosed, poor-risk acute myelogenous leukemia

    PubMed Central

    Karp, Judith E.; Garrett-Mayer, Elizabeth; Estey, Elihu H.; Rudek, Michelle A.; Smith, B. Douglas; Greer, Jacqueline M.; Drye, D. Michelle; Mackey, Karen; Dorcy, Kathleen Shannon; Gore, Steven D.; Levis, Mark J.; McDevitt, Michael A.; Carraway, Hetty E.; Pratz, Keith W.; Gladstone, Douglas E.; Showel, Margaret M.; Othus, Megan; Doyle, L. Austin; Wright, John J.; Pagel, John M.

    2012-01-01

    Background Flavopiridol is a protein-bound, cytotoxic, cyclin dependent kinase inhibitor. A phase II trial of flavopiridol followed by ara-C and mitoxantrone with flavopiridol given by 1-h bolus for adults with newly-diagnosed, poor-risk acute myelogenous leukemia yielded 67% complete remission with median disease-free survival of 13.6 months. Design and Methods We compared bolus flavopiridol (50 mg/m2/day, Arm A) versus 'hybrid' flavopiridol (30 mg/m2 over 30 min followed by 40 mg/m2 over 4 h, Arm B) followed by ara-C and mitoxantrone in 78 patients (39 per arm) with newly diagnosed, poor-risk acute myelogenous leukemia. To mitigate imbalance, patients were stratified by presence or absence of secondary leukemia and therapy for antecedent disorder. Results Death at or before Day 60 occurred in 8% of patients per arm. Complete remission plus complete remission with incomplete recovery was 68% (Arm A, 62%; Arm B, 74%) overall, and 65% or over in both arms for patients with secondary leukemia and leukemia with adverse genetics. In Arm A 91% and in Arm B 86% of patients received chemotherapy and/or allogeneic transplantation in complete remission. Median overall survival for all remission patients has not been reached for either arm, with median disease free survival of 13.6 months for Arm A and of 12.0 months for Arm B. Conclusions Both flavopiridol schedules produce comparably encouraging results in adults with poor-risk acute myelogenous leukemia. Given the greater ease of bolus administration, we are conducting a randomized phase II study of bolus flavopiridol followed by ara-c and mitoxantrone versus conventional induction therapy for patients aged 70 years and under with intermediate or poor-risk acute myelogenous leukemia. This study is registered at www.clinicaltrials.gov as #NCT 00407966. PMID:22733022

  3. Schedule Risk Assessment

    NASA Technical Reports Server (NTRS)

    Smith, Greg

    2003-01-01

    Schedule risk assessments determine the likelihood of finishing on time. Each task in a schedule has a varying degree of probability of being finished on time. A schedule risk assessment quantifies these probabilities by assigning values to each task. This viewgraph presentation contains a flow chart for conducting a schedule risk assessment, and profiles applicable several methods of data analysis.

  4. The Block Scheduling Handbook.

    ERIC Educational Resources Information Center

    Queen, J. Allen

    Block scheduling encourages increased comprehensive immersion into subject matter, improved teacher-student relationships, and decreased disciplinary problems. While block scheduling may offer many advantages, moving to a block schedule from conventional scheduling can be a major adjustment for both students and teachers. This guide is intended to…

  5. Protocols for distributive scheduling

    NASA Technical Reports Server (NTRS)

    Richards, Stephen F.; Fox, Barry

    1993-01-01

    The increasing complexity of space operations and the inclusion of interorganizational and international groups in the planning and control of space missions lead to requirements for greater communication, coordination, and cooperation among mission schedulers. These schedulers must jointly allocate scarce shared resources among the various operational and mission oriented activities while adhering to all constraints. This scheduling environment is complicated by such factors as the presence of varying perspectives and conflicting objectives among the schedulers, the need for different schedulers to work in parallel, and limited communication among schedulers. Smooth interaction among schedulers requires the use of protocols that govern such issues as resource sharing, authority to update the schedule, and communication of updates. This paper addresses the development and characteristics of such protocols and their use in a distributed scheduling environment that incorporates computer-aided scheduling tools. An example problem is drawn from the domain of space shuttle mission planning.

  6. Aspects of job scheduling

    NASA Technical Reports Server (NTRS)

    Phillips, K.

    1976-01-01

    A mathematical model for job scheduling in a specified context is presented. The model uses both linear programming and combinatorial methods. While designed with a view toward optimization of scheduling of facility and plant operations at the Deep Space Communications Complex, the context is sufficiently general to be widely applicable. The general scheduling problem including options for scheduling objectives is discussed and fundamental parameters identified. Mathematical algorithms for partitioning problems germane to scheduling are presented.

  7. Optimizing Operating Room Scheduling.

    PubMed

    Levine, Wilton C; Dunn, Peter F

    2015-12-01

    This article reviews the management of an operating room (OR) schedule and use of the schedule to add value to an organization. We review the methodology of an OR block schedule, daily OR schedule management, and post anesthesia care unit patient flow. We discuss the importance of a well-managed OR schedule to ensure smooth patient care, not only in the OR, but throughout the entire hospital. PMID:26610624

  8. Component duration and relative response rates in multiple schedules.

    NASA Technical Reports Server (NTRS)

    Todorov, J. C.

    1972-01-01

    Pigeons were trained on a multiple variable-interval 30-sec, variable interval 90-sec schedule with each component presented alternately for an equal duration. This duration of exposure was varied from 5 to 300 sec. The rate of response in the variable-interval 30-sec component relative to the rate of response in the variable-interval 90-sec component was studied. Results are plotted and discussed.

  9. Intervals in evolutionary algorithms for global optimization

    SciTech Connect

    Patil, R.B.

    1995-05-01

    Optimization is of central concern to a number of disciplines. Interval Arithmetic methods for global optimization provide us with (guaranteed) verified results. These methods are mainly restricted to the classes of objective functions that are twice differentiable and use a simple strategy of eliminating a splitting larger regions of search space in the global optimization process. An efficient approach that combines the efficient strategy from Interval Global Optimization Methods and robustness of the Evolutionary Algorithms is proposed. In the proposed approach, search begins with randomly created interval vectors with interval widths equal to the whole domain. Before the beginning of the evolutionary process, fitness of these interval parameter vectors is defined by evaluating the objective function at the center of the initial interval vectors. In the subsequent evolutionary process the local optimization process returns an estimate of the bounds of the objective function over the interval vectors. Though these bounds may not be correct at the beginning due to large interval widths and complicated function properties, the process of reducing interval widths over time and a selection approach similar to simulated annealing helps in estimating reasonably correct bounds as the population evolves. The interval parameter vectors at these estimated bounds (local optima) are then subjected to crossover and mutation operators. This evolutionary process continues for predetermined number of generations in the search of the global optimum.

  10. New packet scheduling algorithm in wireless CDMA data networks

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Gao, Zhuo; Li, Shaoqian; Li, Lemin

    2002-08-01

    The future 3G/4G wireless communication systems will provide internet access for mobile users. Packet scheduling algorithms are essential for QoS of diversified data traffics and efficient utilization of radio spectrum.This paper firstly presents a new packet scheduling algorithm DSTTF under the assumption of continuous transmission rates and scheduling intervals for CDMA data networks . Then considering the constraints of discrete transmission rates and fixed scheduling intervals imposed by the practical system, P-DSTTF, a modified version of DSTTF, is brought forward. Both scheduling algorithms take into consideration of channel condition, packet size and traffic delay bounds. The extensive simulation results demonstrate that the proposed scheduling algorithms are superior to some typical ones in current research. In addition, both static and dynamic wireless channel model of multi-level link capacity are established. These channel models sketch better the characterizations of wireless channel than two state Markov model widely adopted by the current literature.

  11. One-way ANOVA based on interval information

    NASA Astrophysics Data System (ADS)

    Hesamian, Gholamreza

    2016-08-01

    This paper deals with extending the one-way analysis of variance (ANOVA) to the case where the observed data are represented by closed intervals rather than real numbers. In this approach, first a notion of interval random variable is introduced. Especially, a normal distribution with interval parameters is introduced to investigate hypotheses about the equality of interval means or test the homogeneity of interval variances assumption. Moreover, the least significant difference (LSD method) for investigating multiple comparison of interval means is developed when the null hypothesis about the equality of means is rejected. Then, at a given interval significance level, an index is applied to compare the interval test statistic and the related interval critical value as a criterion to accept or reject the null interval hypothesis of interest. Finally, the method of decision-making leads to some degrees to accept or reject the interval hypotheses. An applied example will be used to show the performance of this method.

  12. An appraisal of preference for multiple versus mixed schedules1

    PubMed Central

    Hursh, Steven R.; Fantino, Edmund

    1974-01-01

    Pigeons' choice responses on either of two keys occasionally produced entry into a terminal link associated with that key. During the terminal links, responses produced access to grain according to mixed- or multiple-interval schedules. The multiple schedules provided stimuli correlated with the interval of time preceding reinforcement whereas the mixed schedules did not. The two subjects reliably preferred the multiple schedules to the mixed schedules throughout a series of replications. Preference for the multiple schedule was much smaller than suggested by earlier work comparing multiple and mixed schedules that had much higher rates of entry into the terminal links. Preference for the multiple schedule was greatly increased in this study when the rate of entry into the terminal schedules was increased. As in previous studies, these high preferences may have been the result of a sharp increase in the number of reinforcements on the multiple (as opposed to the mixed) schedule. The reliable but smaller preferences for the multiple schedule found with lower rates of entry into the terminal links were unconfounded by differences in the number of reinforcements obtained in the two terminal links. PMID:16811784

  13. A molar theory of reinforcement schedules

    PubMed Central

    Rachlin, Howard

    1978-01-01

    Behavior of subjects exposed to concurrent and individual interval and ratio schedules of reinforcement may be described in terms of a set of expressions relating the value of responses to their durations, a feedback equation relating reinforcement to response duration, and the assumption that subjects allocate their time among various responses so as to maximize value. PMID:16812114

  14. The Effects of Practice Schedule on Learning a Complex Judgment Task

    ERIC Educational Resources Information Center

    Helsdingen, Anne S.; van Gog, Tamara; van Merrienboer, Jeroen J. G.

    2011-01-01

    The effects of practice schedule on learning a complex judgment task were investigated. In Experiment 1, participants' judgment accuracy on a retention test was higher after a random practice schedule than after a blocked schedule or operational schedule. Experiment 2 demonstrated that judgment on a transfer test was also better after a random…

  15. Limited Matching on Concurrent-Schedule Reinforcement of Academic Behavior.

    ERIC Educational Resources Information Center

    Mace, F. Charles; And Others

    1994-01-01

    Three adolescent students with special educational needs were given reinforcers (nickels) according to three different concurrent variable-interval schedules. Time allocated to the assigned tasks was in linear relationship to the reinforcement rate. However, changes in reinforcement schedules were not followed by changes in allocation patterns…

  16. 5 CFR 532.207 - Time schedule for wage surveys.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Time schedule for wage surveys. 532.207... PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.207 Time schedule for wage surveys. (a) Wage surveys shall be conducted on a 2-year cycle at annual intervals. (b) A full-scale survey shall be made...

  17. Dedicated heterogeneous node scheduling including backfill scheduling

    DOEpatents

    Wood, Robert R.; Eckert, Philip D.; Hommes, Gregg

    2006-07-25

    A method and system for job backfill scheduling dedicated heterogeneous nodes in a multi-node computing environment. Heterogeneous nodes are grouped into homogeneous node sub-pools. For each sub-pool, a free node schedule (FNS) is created so that the number of to chart the free nodes over time. For each prioritized job, using the FNS of sub-pools having nodes useable by a particular job, to determine the earliest time range (ETR) capable of running the job. Once determined for a particular job, scheduling the job to run in that ETR. If the ETR determined for a lower priority job (LPJ) has a start time earlier than a higher priority job (HPJ), then the LPJ is scheduled in that ETR if it would not disturb the anticipated start times of any HPJ previously scheduled for a future time. Thus, efficient utilization and throughput of such computing environments may be increased by utilizing resources otherwise remaining idle.

  18. Immunization Schedules for Adults

    MedlinePlus

    ... ACIP Vaccination Recommendations Why Immunize? Vaccines: The Basics Immunization Schedules for Adults in Easy-to-read Formats ... previous immunizations. View or Print a Schedule Recommended Immunizations for Adults (19 Years and Older) by Age ...

  19. Childhood Immunization Schedule

    MedlinePlus

    ... Recommendations Why Immunize? Vaccines: The Basics Instant Childhood Immunization Schedule Recommend on Facebook Tweet Share Compartir Get ... date. See Disclaimer for additional details. Based on Immunization Schedule for Children 0 through 6 Years of ...

  20. Effects of inter-food interval on the variety effect in an instrumental food-seeking task. Clarifying the role of habituation☆

    PubMed Central

    Thrailkill, Eric A.; Epstein, Leonard H.; Bouton, Mark E.

    2014-01-01

    Food variety increases consumption and the rate of instrumental behavior that is reinforced by food in humans and animals. The present experiment investigated the relationship between the variety effect and habituation to food by testing the role of the interval between successive food presentations on responding in an operant food-seeking task. Habituation to food was expected at short, but not long, interfood intervals. The effects of variety on food’s long-term reinforcing value were also tested. Four groups of rats were trained to lever-press on different random-interval (RI) schedules of reinforcement to earn 45-mg food pellets. Half the rats in each group received an unpredictable mix of grain and sucrose pellets, while the other half consistently received sucrose pellets. Response rate began at a high rate and then decreased within each 30-min session for groups that received short inter-pellet intervals (i.e., RI-3 s and RI-6 s reinforcement schedules) but not in groups that received longer inter-pellet intervals (i.e., RI-12 s and RI-24 s). A variety effect in the form of higher responding in the mix group than the sucrose-only group was also only evident at the shorter intervals. Habituation and variety effects were also most evident with the short intervals when we controlled for the number of reinforcers earned, suggesting that they were not merely due to rapid satiation. The variety effect also appeared quickly when groups trained with longer inter-pellet intervals (RI-12 s and RI-24 s) were transitioned to shorter intervals (RI-3 s and RI-6 s). There was no effect of variety on resistance to extinction or on resistance to the response-suppressing effects of pre-session feeding. The results more clearly link this version of the variety effect to the short-term effect of variety on food habituation. PMID:25261732

  1. Schedule Risk Assessment

    NASA Technical Reports Server (NTRS)

    Smith, Greg

    2003-01-01

    Schedule Risk Assessment needs to determine the probability of finishing on or before a given point in time. Task in a schedule should reflect the "most likely" duration for each task. IN reality, each task is different and has a varying degree of probability of finishing within or after the duration specified. Schedule risk assessment attempt to quantify these probabilities by assigning values to each task. Bridges the gap between CPM scheduling and the project's need to know the likelihood of "when".

  2. Reinforcement learning in scheduling

    NASA Technical Reports Server (NTRS)

    Dietterich, Tom G.; Ok, Dokyeong; Zhang, Wei; Tadepalli, Prasad

    1994-01-01

    The goal of this research is to apply reinforcement learning methods to real-world problems like scheduling. In this preliminary paper, we show that learning to solve scheduling problems such as the Space Shuttle Payload Processing and the Automatic Guided Vehicle (AGV) scheduling can be usefully studied in the reinforcement learning framework. We discuss some of the special challenges posed by the scheduling domain to these methods and propose some possible solutions we plan to implement.

  3. Parallel scheduling algorithms

    SciTech Connect

    Dekel, E.; Sahni, S.

    1983-01-01

    Parallel algorithms are given for scheduling problems such as scheduling to minimize the number of tardy jobs, job sequencing with deadlines, scheduling to minimize earliness and tardiness penalties, channel assignment, and minimizing the mean finish time. The shared memory model of parallel computers is used to obtain fast algorithms. 26 references.

  4. Block Scheduling. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2003-01-01

    What are the effects of block scheduling? Results of transitioning from traditional to block scheduling are mixed. Some studies indicate no change in achievement results, nor change in teachers' opinions about instructional strategies. Other studies show that block scheduling doesn't work well for Advanced Placement or Music courses, that "hard to…

  5. Schedule-induced mirror responding in the pigeon1

    PubMed Central

    Cohen, Perrin S.; Looney, Thomas A.

    1973-01-01

    Two pigeons that were previously exposed to a multiple schedule of reinforcement in the presence of a stuffed and a live pigeon, and two of three naive pigeons, responded on a mirror during exposure to multiple fixed-ratio, fixed-ratio schedules of reinforcement for key pecking. Both the topography and temporal pattern of mirror responding were comparable to schedule-induced “attack” on live and stuffed targets. Rate of target responding was reduced when either the mirror was covered with paper or when the multiple schedule was removed. A reversal in the relationship between reinforcement schedules and discriminative stimuli demonstrated that mirror responding was controlled by the stimulus correlated with the higher fixed-ratio schedule. With one component of the multiple schedule held constant at fixed ratio 25 and the ratio requirement of the other component varying from 25 to 150, there was an inverted U-shaped relationship between rate of mirror responding and fixed-ratio schedule in the varied component. As in Flory's study (1969b) there was an inverted U-shaped relationship between target responding and inter-food intervals. The combined results of these studies suggest that the relationship between rate of target responding and reinforcement schedules is controlled primarily by the inter-food intervals resulting from the schedules. PMID:16811671

  6. Interval polynomial positivity

    NASA Technical Reports Server (NTRS)

    Bose, N. K.; Kim, K. D.

    1989-01-01

    It is shown that a univariate interval polynomial is globally positive if and only if two extreme polynomials are globally positive. It is shown that the global positivity property of a bivariate interval polynomial is completely determined by four extreme bivariate polynomials. The cardinality of the determining set for k-variate interval polynomials is 2k. One of many possible generalizations, where vertex implication for global positivity holds, is made by considering the parameter space to be the set dual of a boxed domain.

  7. Estimation of natural history parameters of breast cancer based on non-randomized organized screening data: subsidiary analysis of effects of inter-screening interval, sensitivity, and attendance rate on reduction of advanced cancer.

    PubMed

    Wu, Jenny Chia-Yun; Hakama, Matti; Anttila, Ahti; Yen, Amy Ming-Fang; Malila, Nea; Sarkeala, Tytti; Auvinen, Anssi; Chiu, Sherry Yueh-Hsia; Chen, Hsiu-Hsi

    2010-07-01

    Estimating the natural history parameters of breast cancer not only elucidates the disease progression but also make contributions to assessing the impact of inter-screening interval, sensitivity, and attendance rate on reducing advanced breast cancer. We applied three-state and five-state Markov models to data on a two-yearly routine mammography screening in Finland between 1988 and 2000. The mean sojourn time (MST) was computed from estimated transition parameters. Computer simulation was implemented to examine the effect of inter-screening interval, sensitivity, and attendance rate on reducing advanced breast cancers. In three-state model, the MST was 2.02 years, and the sensitivity for detecting preclinical breast cancer was 84.83%. In five-state model, the MST was 2.21 years for localized tumor and 0.82 year for non-localized tumor. Annual, biennial, and triennial screening programs can reduce 53, 37, and 28% of advanced cancer. The effectiveness of intensive screening with poor attendance is the same as that of infrequent screening with high attendance rate. We demonstrated how to estimate the natural history parameters using a service screening program and applied these parameters to assess the impact of inter-screening interval, sensitivity, and attendance rate on reducing advanced cancer. The proposed method makes contribution to further cost-effectiveness analysis. However, these findings had better be validated by using a further long-term follow-up data. PMID:20054645

  8. DSN Scheduling Engine

    NASA Technical Reports Server (NTRS)

    Clement, Bradley; Johnston, Mark; Wax, Allan; Chouinard, Caroline

    2008-01-01

    The DSN (Deep Space Network) Scheduling Engine targets all space missions that use DSN services. It allows clients to issue scheduling, conflict identification, conflict resolution, and status requests in XML over a Java Message Service interface. The scheduling requests may include new requirements that represent a set of tracks to be scheduled under some constraints. This program uses a heuristic local search to schedule a variety of schedule requirements, and is being infused into the Service Scheduling Assembly, a mixed-initiative scheduling application. The engine resolves conflicting schedules of resource allocation according to a range of existing and possible requirement specifications, including optional antennas; start of track and track duration ranges; periodic tracks; locks on track start, duration, and allocated antenna; MSPA (multiple spacecraft per aperture); arraying/VLBI (very long baseline interferometry)/delta DOR (differential one-way ranging); continuous tracks; segmented tracks; gap-to-track ratio; and override or block-out of requirements. The scheduling models now include conflict identification for SOA(start of activity), BOT (beginning of track), RFI (radio frequency interference), and equipment constraints. This software will search through all possible allocations while providing a best-effort solution at any time. The engine reschedules to accommodate individual emergency tracks in 0.2 second, and emergency antenna downtime in 0.2 second. The software handles doubling of one mission's track requests over one week (to 42 total) in 2.7 seconds. Further tests will be performed in the context of actual schedules.

  9. NASA scheduling technologies

    NASA Technical Reports Server (NTRS)

    Adair, Jerry R.

    1994-01-01

    This paper is a consolidated report on ten major planning and scheduling systems that have been developed by the National Aeronautics and Space Administration (NASA). A description of each system, its components, and how it could be potentially used in private industry is provided in this paper. The planning and scheduling technology represented by the systems ranges from activity based scheduling employing artificial intelligence (AI) techniques to constraint based, iterative repair scheduling. The space related application domains in which the systems have been deployed vary from Space Shuttle monitoring during launch countdown to long term Hubble Space Telescope (HST) scheduling. This paper also describes any correlation that may exist between the work done on different planning and scheduling systems. Finally, this paper documents the lessons learned from the work and research performed in planning and scheduling technology and describes the areas where future work will be conducted.

  10. Iterative modulo scheduling

    SciTech Connect

    Rau, B.R.

    1996-02-01

    Modulo scheduling is a framework within which algorithms for software pipelining innermost loops may be defined. The framework specifies a set of constraints that must be met in order to achieve a legal modulo schedule. A wide variety of algorithms and heuristics can be defined within this framework. Little work has been done to evaluate and compare alternative algorithms and heuristics for modulo scheduling from the viewpoints of schedule quality as well as computational complexity. This, along with a vague and unfounded perception that modulo scheduling is computationally expensive as well as difficult to implement, have inhibited its corporation into product compilers. This paper presents iterative modulo scheduling, a practical algorithm that is capable of dealing with realistic machine models. The paper also characterizes the algorithm in terms of the quality of the generated schedules as well as the computational incurred.

  11. Concurrent Second-Order Schedules: Some Effects of Variations in Response Number and Duration

    ERIC Educational Resources Information Center

    Sealey, Diane M.; Sumpter, Catherine E.; Temple, W.; Foster, T. Mary

    2005-01-01

    To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second- order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed- interval schedule, with one further…

  12. PLAN-IT: Scheduling assistant for solar system exploration

    NASA Technical Reports Server (NTRS)

    Dias, William C.; Henricks, Julia A.; Wong, Jennifer C.

    1987-01-01

    A frame-based expert scheduling system shell, PLAN-IT, is developed for spacecraft scheduling in the Request Integration Phase, using the Comet Rendezvous Asteroid Flyby (CRAF) mission as a development base. Basic, structured, and expert scheduling techniques are reviewed. Data elements such as activity representation and resource conflict representation are discussed. Resource constraints include minimum and maximum separation times between activities, percentage of time pointed at specific targets, and separation time between targeted intervals of a given activity. The different scheduling technique categories and the rationale for their selection are also considered.

  13. PLAN-IT - Scheduling assistant for solar system exploration

    NASA Technical Reports Server (NTRS)

    Dias, William C.; Henricks, Julia A.; Wong, Jennifer C.

    1987-01-01

    A frame-based expert scheduling system shell, PLAN-IT, is developed for spacecraft scheduling in the Request Integration Phase, using the Comet Rendezvous Asteroid Flyby (CRAF) mission as a development base. Basic, structured, and expert scheduling techniques are reviewed. Data elements such as activity representation and resource conflict representation are discussed. Resource constraints include minimum and maximum separation times between activities, percentage of time pointed at specific targets, and separation time between targeted intervals of a given activity. The different scheduling technique categories and the rationale for their selection are also considered.

  14. Schedule-Organizer Computer Program

    NASA Technical Reports Server (NTRS)

    Collazo, Fernando F.

    1990-01-01

    Schedule Organizer provides simple method for generating distribution lists. Contains readers' names for each task schedule defined by input files. Schedule Organizer (SO), Schedule Tracker (ST) (COSMIC program MSC-21526), and Schedule Report Generator (SRG) (COSMIC program MSC-21527) computer programs manipulating data-base files in ways advantageous in scheduling. Written in PL/1 and DEC Command Language (DCL).

  15. A Synthesized Heuristic Task Scheduling Algorithm

    PubMed Central

    Dai, Yanyan; Zhang, Xiangli

    2014-01-01

    Aiming at the static task scheduling problems in heterogeneous environment, a heuristic task scheduling algorithm named HCPPEFT is proposed. In task prioritizing phase, there are three levels of priority in the algorithm to choose task. First, the critical tasks have the highest priority, secondly the tasks with longer path to exit task will be selected, and then algorithm will choose tasks with less predecessors to schedule. In resource selection phase, the algorithm is selected task duplication to reduce the interresource communication cost, besides forecasting the impact of an assignment for all children of the current task permits better decisions to be made in selecting resources. The algorithm proposed is compared with STDH, PEFT, and HEFT algorithms through randomly generated graphs and sets of task graphs. The experimental results show that the new algorithm can achieve better scheduling performance. PMID:25254244

  16. Fixed-Time Schedule Effects in Combination with Response-Dependent Schedules

    ERIC Educational Resources Information Center

    Borrero, John C.; Bartels-Meints, Jamie A.; Sy, Jolene R.; Francisco, Monica T.

    2011-01-01

    We evaluated the effects of fixed-interval (FI), fixed-time (FT), and conjoint (combined) FI FT reinforcement schedules on the responding of 3 adults who had been diagnosed with schizophrenia. Responding on vocational tasks decreased for 2 of 3 participants under FT alone relative to FI alone. Responding under FI FT resulted in response…

  17. Integrated resource scheduling in a distributed scheduling environment

    NASA Technical Reports Server (NTRS)

    Zoch, David; Hall, Gardiner

    1988-01-01

    The Space Station era presents a highly-complex multi-mission planning and scheduling environment exercised over a highly distributed system. In order to automate the scheduling process, customers require a mechanism for communicating their scheduling requirements to NASA. A request language that a remotely-located customer can use to specify his scheduling requirements to a NASA scheduler, thus automating the customer-scheduler interface, is described. This notation, Flexible Envelope-Request Notation (FERN), allows the user to completely specify his scheduling requirements such as resource usage, temporal constraints, and scheduling preferences and options. The FERN also contains mechanisms for representing schedule and resource availability information, which are used in the inter-scheduler inconsistency resolution process. Additionally, a scheduler is described that can accept these requests, process them, generate schedules, and return schedule and resource availability information to the requester. The Request-Oriented Scheduling Engine (ROSE) was designed to function either as an independent scheduler or as a scheduling element in a network of schedulers. When used in a network of schedulers, each ROSE communicates schedule and resource usage information to other schedulers via the FERN notation, enabling inconsistencies to be resolved between schedulers. Individual ROSE schedules are created by viewing the problem as a constraint satisfaction problem with a heuristically guided search strategy.

  18. Arousal, changeover responses, and preference in concurrent schedules.

    PubMed Central

    McDevitt, Margaret A; Williams, Ben A

    2003-01-01

    Pigeons were trained on multiple schedules that provided concurrent reinforcement in each of two components. In Experiment 1, one component consisted of a variable-interval (VI) 40-s schedule presented with a VI 20-s schedule, and the other a VI 40-s schedule presented with a VI 80-s schedule. After extended training, probe tests measured preference between the stimuli associated with the two 40-s schedules. Probe tests replicated the results of Belke (1992) that showed preference for the 40-s schedule that had been paired with the 80-s schedule. In a second condition, the overall reinforcer rate provided by the two components was equated by adding a signaled VI schedule to the component with the lower reinforcer rate. Probe results were unchanged. In Experiment 2, pigeons were trained on alternating concurrent VI 30-s VI 60-s schedules. One schedule provided 2-s access to food and the other provided 6-s access. The larger reinforcer magnitude produced higher response rates and was preferred on probe trials. Rate of changeover responding, however, did not differ as a function of reinforcer magnitude. The present results demonstrate that preference on probe trials is not a simple reflection of the pattern of changeover behavior established during training. PMID:14964707

  19. Student and Faculty Preferences for Class Scheduling Patterns.

    ERIC Educational Resources Information Center

    Noonan, Roberta L.

    A random sample of 55 faculty and 593 students in 28 classes was surveyed to determine class scheduling preferences for three-semester-hour courses and to relate them to existing scheduling patterns at Moraine Valley Community College. Fifty-five percent of the students preferred two 90-minute class sessions per week, 27% preferred one three-hour…

  20. Automated telescope scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1988-01-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  1. Automated telescope scheduling

    NASA Astrophysics Data System (ADS)

    Johnston, Mark D.

    1988-08-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  2. The range scheduling aid

    NASA Technical Reports Server (NTRS)

    Halbfinger, Eliezer M.; Smith, Barry D.

    1991-01-01

    The Air Force Space Command schedules telemetry, tracking and control activities across the Air Force Satellite Control network. The Range Scheduling Aid (RSA) is a rapid prototype combining a user-friendly, portable, graphical interface with a sophisticated object-oriented database. The RSA has been a rapid prototyping effort whose purpose is to elucidate and define suitable technology for enhancing the performance of the range schedulers. Designing a system to assist schedulers in their task and using their current techniques as well as enhancements enabled by an electronic environment, has created a continuously developing model that will serve as a standard for future range scheduling systems. The RSA system is easy to use, easily ported between platforms, fast, and provides a set of tools for the scheduler that substantially increases his productivity.

  3. Interval neural networks

    SciTech Connect

    Patil, R.B.

    1995-05-01

    Traditional neural networks like multi-layered perceptrons (MLP) use example patterns, i.e., pairs of real-valued observation vectors, ({rvec x},{rvec y}), to approximate function {cflx f}({rvec x}) = {rvec y}. To determine the parameters of the approximation, a special version of the gradient descent method called back-propagation is widely used. In many situations, observations of the input and output variables are not precise; instead, we usually have intervals of possible values. The imprecision could be due to the limited accuracy of the measuring instrument or could reflect genuine uncertainty in the observed variables. In such situation input and output data consist of mixed data types; intervals and precise numbers. Function approximation in interval domains is considered in this paper. We discuss a modification of the classical backpropagation learning algorithm to interval domains. Results are presented with simple examples demonstrating few properties of nonlinear interval mapping as noise resistance and finding set of solutions to the function approximation problem.

  4. Optimising retention through multiple study opportunities over days: The benefit of an expanding schedule of repetitions.

    PubMed

    Gerbier, Emilie; Toppino, Thomas C; Koenig, Olivier

    2015-01-01

    Few studies have investigated how scheduling repeated studies of the same material over several days influences its subsequent retention. The study-phase retrieval hypothesis predicts that, under these circumstances, expanding intervals between repetitions will promote the greatest likelihood that the participant will be reminded of previous occurrences of the item, thus leading to a benefit for subsequent recall. In the present article, participants studied vocabulary pairs that were repeated according to one of three schedules. In the expanding schedule, pairs were presented on days 1, 2 and 13; in the uniform schedule, on days 1, 7 and 13; and in the contracting schedule, on days 1, 12 and 13. Cued-recall was assessed after a retention interval (RI) of 2, 6 or 13 days. Consistent with predictions, the expanding schedule generally led to better performance than the other schedules. However, further analyses suggested that the benefit of an expanding schedule may be greater when the RI is longer. PMID:25116727

  5. Comparison of the effects of D-amphetamine on FI and DRL schedule performance of self-stimulating rats.

    PubMed

    Nalwa, V; Rao, P S

    1984-01-01

    Six rats bar-pressed for intracranial self-stimulation in a Skinner box on fixed interval and differential reinforcement of low rate schedules with an interval parameter of 1.3 s. After amphetamine timing efficiency was reduced immediately on both the schedules; it recovered after 60 min on the DRL schedule but not within 120 min on the FI schedule. Response rates increased on both the schedules. The increased response rates correlated with the low efficiency on the DRL but not on the FI schedule. The selective sparing of DRL performance is in line with the similarity between the effects of amphetamine and frontal cortical lesions. PMID:6744685

  6. Proper Interval Vertex Deletion

    NASA Astrophysics Data System (ADS)

    Villanger, Yngve

    Deleting a minimum number of vertices from a graph to obtain a proper interval graph is an NP-complete problem. At WG 2010 van Bevern et al. gave an O((14k + 14) k + 1 kn 6) time algorithm by combining iterative compression, branching, and a greedy algorithm. We show that there exists a simple greedy O(n + m) time algorithm that solves the Proper Interval Vertex Deletion problem on \\{claw,net,allowbreak tent,allowbreak C_4,C_5,C_6\\}-free graphs. Combining this with branching on the forbidden structures claw,net,tent,allowbreak C_4,C_5, and C 6 enables us to get an O(kn 6 6 k ) time algorithm for Proper Interval Vertex Deletion, where k is the number of deleted vertices.

  7. Interval timing in Siamese fighting fish (Betta splendens).

    PubMed

    Higa, J J; Simm, L A

    2004-11-30

    The present study evaluated the temporal performance of Siamese fighting fish (Betta splendens) given short-term exposure to four fixed interval (FI) schedules of reinforcement, FI 30, 60, 120, and 240 s, during which a reinforcer (mirror image) was given for the first response (swimming through a hoop) after the interval requirement had elapsed. Response levels were generally low early in an interval and increased as the interval elapsed; wait times and break points in an interval increased with increases in the FI requirement. The results were similar to that obtained with other species and different types of responses and reinforcers, and demonstrate that the procedure is a feasible method for studying interval timing in fish. PMID:15518999

  8. Optimal radiotherapy dose schedules under parametric uncertainty

    NASA Astrophysics Data System (ADS)

    Badri, Hamidreza; Watanabe, Yoichi; Leder, Kevin

    2016-01-01

    We consider the effects of parameter uncertainty on the optimal radiation schedule in the context of the linear-quadratic model. Our interest arises from the observation that if inter-patient variability in normal and tumor tissue radiosensitivity or sparing factor of the organs-at-risk (OAR) are not accounted for during radiation scheduling, the performance of the therapy may be strongly degraded or the OAR may receive a substantially larger dose than the allowable threshold. This paper proposes a stochastic radiation scheduling concept to incorporate inter-patient variability into the scheduling optimization problem. Our method is based on a probabilistic approach, where the model parameters are given by a set of random variables. Our probabilistic formulation ensures that our constraints are satisfied with a given probability, and that our objective function achieves a desired level with a stated probability. We used a variable transformation to reduce the resulting optimization problem to two dimensions. We showed that the optimal solution lies on the boundary of the feasible region and we implemented a branch and bound algorithm to find the global optimal solution. We demonstrated how the configuration of optimal schedules in the presence of uncertainty compares to optimal schedules in the absence of uncertainty (conventional schedule). We observed that in order to protect against the possibility of the model parameters falling into a region where the conventional schedule is no longer feasible, it is required to avoid extremal solutions, i.e. a single large dose or very large total dose delivered over a long period. Finally, we performed numerical experiments in the setting of head and neck tumors including several normal tissues to reveal the effect of parameter uncertainty on optimal schedules and to evaluate the sensitivity of the solutions to the choice of key model parameters.

  9. A study of the impact of scheduling parameters in heterogeneous computing environments

    SciTech Connect

    Powers, Sarah S

    2014-01-01

    This paper describes a tool for exploring system scheduler parameter settings in a heterogeneous computing environment. Through the coupling of simulation and optimization techniques, this work investigates optimal scheduling intervals, the impact of job arrival prediction on scheduling, as well as how to best apply fair use policies. The developed simulation framework is quick and modular, enabling decision makers to further explore decisions in real-time regarding scheduling policies or parameter changes.

  10. Surviving Block Scheduling.

    ERIC Educational Resources Information Center

    Haley, Marjorie

    A discussion of block scheduling for second language instruction looks at the advantages and disadvantages and offers some suggestions for classroom management and course organization. It is argued that block scheduling may offer a potential solution to large classes, insufficient time for labs, too little individualized instruction; few…

  11. Block Scheduling Revisited.

    ERIC Educational Resources Information Center

    Queen, J. Allen

    2000-01-01

    Successful block scheduling depends on provision of initial and ongoing instructional training. Teaching strategies should vary and include cooperative learning, the case method, the socratic seminar, synectics, concept attainment, the inquiry method, and simulations. Recommendations for maximizing block scheduling are outlined. (Contains 52…

  12. A Fluid Block Schedule

    ERIC Educational Resources Information Center

    Ubben, Gerald C.

    1976-01-01

    Achieving flexibility without losing student accountability is a challenge that faces every school. With a fluid block schedule, as described here, accountability is maintained without inhibiting flexibility. An additional advantage is that three levels of schedule decision making take some of the pressure off the principal. (Editor)

  13. Trimester Schedule. Research Brief

    ERIC Educational Resources Information Center

    Education Partnerships, Inc., 2012

    2012-01-01

    Why do a trimester schedule? With the advent of block scheduling, many high schools conducted research on utilizing that plan in a trimester format. There appeared to be three issues that most schools faced: (1) How to provide substantive instructional time that was not fragmented?; (2) How does the school climate contribute positively to…

  14. Range Scheduling Aid (RSA)

    NASA Technical Reports Server (NTRS)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  15. Scheduling: Seven Period Day

    ERIC Educational Resources Information Center

    Williamson, Ronald

    2010-01-01

    Driven by stable or declining financial resources many school districts are considering the costs and benefits of a seven-period day. While there is limited evidence that any particular scheduling model has a greater impact on student learning than any other, it is clear that the school schedule is a tool that can significantly impact teacher…

  16. DSN Resource Scheduling

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Baldwin, John

    2007-01-01

    TIGRAS is client-side software, which provides tracking-station equipment planning, allocation, and scheduling services to the DSMS (Deep Space Mission System). TIGRAS provides functions for schedulers to coordinate the DSN (Deep Space Network) antenna usage time and to resolve the resource usage conflicts among tracking passes, antenna calibrations, maintenance, and system testing activities. TIGRAS provides a fully integrated multi-pane graphical user interface for all scheduling operations. This is a great improvement over the legacy VAX VMS command line user interface. TIGRAS has the capability to handle all DSN resource scheduling aspects from long-range to real time. TIGRAS assists NASA mission operations for DSN tracking of station equipment resource request processes from long-range load forecasts (ten years or longer), to midrange, short-range, and real-time (less than one week) emergency tracking plan changes. TIGRAS can be operated by NASA mission operations worldwide to make schedule requests for the DSN station equipment.

  17. A MIP Model for Rolling Horizon Surgery Scheduling.

    PubMed

    Luo, Li; Luo, Yong; You, Yang; Cheng, Yuanjun; Shi, Yingkang; Gong, Renrong

    2016-05-01

    Most surgery scheduling is done 1 day in advance. Caused by lack of overall planning, this scheduling scheme often results in unbalanced occupancy time of the operating rooms. So we put forward a rolling horizon mixed integer programming model for the scheduling. Rolling horizon scheduling refers to a scheduling scheme in which cyclic surgical requests are taken into account. Surgical requests are updated daily. The completed surgeries are eliminated, and new surgeries are added to the scheduling list. Considering day-to-day demand for surgery, we develop a non-rolling scheduling model (NRSM) and a rolling horizon scheduling model (RSM). By comparing the two, we find that the quality of surgery scheduling is significantly influenced by the variation in demand from day to day. A rolling horizon scheduling will enable a more flexible planning of the pool of surgeries that have not been scheduled into this main blocks, and hence minimize the idle time of operating rooms. The strategy of the RSM helps balance the occupancy time among operating rooms. Using surgical data from five departments of the West China Hospital (WCH), we generate surgical demands randomly to compare the NRSM and the RSM. The results show the operating rooms' average utilization rate using RSM is significantly higher than when applying NRSM. PMID:27071394

  18. Reinforcement schedule thinning following treatment with functional communication training.

    PubMed Central

    Hanley, G P; Iwata, B A; Thompson, R H

    2001-01-01

    We evaluated four methods for increasing the practicality of functional communication training (FCT) by decreasing the frequency of reinforcement for alternative behavior. Three participants whose problem behaviors were maintained by positive reinforcement were treated successfully with FCT in which reinforcement for alternative behavior was initially delivered on fixed-ratio (FR) 1 schedules. One participant was then exposed to increasing delays to reinforcement under FR 1, a graduated fixed-interval (FI) schedule, and a graduated multiple-schedule arrangement in which signaled periods of reinforcement and extinction were alternated. Results showed that (a) increasing delays resulted in extinction of the alternative behavior, (b) the FI schedule produced undesirably high rates of the alternative behavior, and (c) the multiple schedule resulted in moderate and stable levels of the alternative behavior as the duration of the extinction component was increased. The other 2 participants were exposed to graduated mixed-schedule (unsignaled alternation between reinforcement and extinction components) and multiple-schedule (signaled alternation between reinforcement and extinction components) arrangements in which the durations of the reinforcement and extinction components were modified. Results obtained for these 2 participants indicated that the use of discriminative stimuli in the multiple schedule facilitated reinforcement schedule thinning. Upon completion of treatment, problem behavior remained low (or at zero), whereas alternative behavior was maintained as well as differentiated during a multiple-schedule arrangement consisting of a 4-min extinction period followed by a 1-min reinforcement period. PMID:11317985

  19. A Comparison of Techniques for Scheduling Earth-Observing Satellites

    NASA Technical Reports Server (NTRS)

    Globus, Al; Crawford, James; Lohn, Jason; Pryor, Anna

    2004-01-01

    Scheduling observations by coordinated fleets of Earth Observing Satellites (EOS) involves large search spaces, complex constraints and poorly understood bottlenecks, conditions where evolutionary and related algorithms are often effective. However, there are many such algorithms and the best one to use is not clear. Here we compare multiple variants of the genetic algorithm: stochastic hill climbing, simulated annealing, squeaky wheel optimization and iterated sampling on ten realistically-sized EOS scheduling problems. Schedules are represented by a permutation (non-temperal ordering) of the observation requests. A simple deterministic scheduler assigns times and resources to each observation request in the order indicated by the permutation, discarding those that violate the constraints created by previously scheduled observations. Simulated annealing performs best. Random mutation outperform a more 'intelligent' mutator. Furthermore, the best mutator, by a small margin, was a novel approach we call temperature dependent random sampling that makes large changes in the early stages of evolution and smaller changes towards the end of search.

  20. 47 CFR 1.1103 - Schedule of charges for equipment approval, experimental radio services (or service).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Schedule of charges for equipment approval, experimental radio services (or service). 1.1103 Section 1.1103 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Schedule of Statutory Charges and Procedures for Payment § 1.1103 Schedule...

  1. NASA Schedule Management Handbook

    NASA Technical Reports Server (NTRS)

    2011-01-01

    The purpose of schedule management is to provide the framework for time-phasing, resource planning, coordination, and communicating the necessary tasks within a work effort. The intent is to improve schedule management by providing recommended concepts, processes, and techniques used within the Agency and private industry. The intended function of this handbook is two-fold: first, to provide guidance for meeting the scheduling requirements contained in NPR 7120.5, NASA Space Flight Program and Project Management Requirements, NPR 7120.7, NASA Information Technology and Institutional Infrastructure Program and Project Requirements, NPR 7120.8, NASA Research and Technology Program and Project Management Requirements, and NPD 1000.5, Policy for NASA Acquisition. The second function is to describe the schedule management approach and the recommended best practices for carrying out this project control function. With regards to the above project management requirements documents, it should be noted that those space flight projects previously established and approved under the guidance of prior versions of NPR 7120.5 will continue to comply with those requirements until project completion has been achieved. This handbook will be updated as needed, to enhance efficient and effective schedule management across the Agency. It is acknowledged that most, if not all, external organizations participating in NASA programs/projects will have their own internal schedule management documents. Issues that arise from conflicting schedule guidance will be resolved on a case by case basis as contracts and partnering relationships are established. It is also acknowledged and understood that all projects are not the same and may require different levels of schedule visibility, scrutiny and control. Project type, value, and complexity are factors that typically dictate which schedule management practices should be employed.

  2. Effects of primary reinforcement on pigeons' initial-link responding under a concurrent chains schedule with nondifferntial terminal links.

    PubMed Central

    Ploog, B O

    2001-01-01

    The effect of primary reinforcement on initial-link responding under concurrent-chains schedules with nondifferential terminal links was assessed in 12 pigeons. The iniitial and terminal links were variable-interval schedules (always the same for both alternatives). The positions (left or right key) of the initial-link stimuli (red or green) were randomized while the correlation between color and food amount remained constant within each condition. The terminal-link stimuli were always presented on the center key. Except in two control groups and conditions, the terminal-link stimuli were the same color (nondifferential, blue or yellow). Over six conditions, the differences in food amont and the durations of the initial- and terminal-link schedules were manipulated. In 57 of 60 cases, birds generated choice proportions above .50 in favor of the initial-link stimlus that was correlated with the larger reinforcer. There was some indication that preference increased with shortened terminal-link durations. Because the terminal-link stimuli were nondifferential, differential responding in the initial links cannot be explained easily by conditioned reinforcement represented by the terminal-link stimuli. Thus, primiary reinforcement has a direct effect on initial-link responding in concurrent-chains schedules. PMID:11516116

  3. Interval arithmetic operations for uncertainty analysis with correlated interval variables

    NASA Astrophysics Data System (ADS)

    Jiang, Chao; Fu, Chun-Ming; Ni, Bing-Yu; Han, Xu

    2016-08-01

    A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analysis could be significantly alleviated. The correlation between interval parameters is defined by the multidimensional parallelepiped model which is convenient to describe the correlative and independent interval variables in a unified framework. The original interval variables with correlation are transformed into the standard space without correlation, and then the relationship between the original variables and the standard interval variables is obtained. The expressions of four basic interval arithmetic operations, namely addition, subtraction, multiplication, and division, are given in the standard space. Finally, several numerical examples and a two-step bar are used to demonstrate the effectiveness of the proposed method.

  4. Scheduling and Utilization.

    ERIC Educational Resources Information Center

    Blakesley, James F.

    1982-01-01

    College scheduling system and operating procedure objectives influence efficient use of resources. Theoretical and practical considerations are outlined, including a step-by-step assessment of an institution's enrollment capacity and discussion of centralized or reassignable classrooms. (Author/MSE)

  5. Childhood Vaccine Schedule

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues Childhood Vaccine Schedule Past Issues / Spring 2008 Table of Contents ... please turn Javascript on. When to Vaccinate What Vaccine Why Birth (or any age if not previously ...

  6. Schedule Risk Assessment

    NASA Technical Reports Server (NTRS)

    Smith, Grego

    2004-01-01

    Schedule Risk Assessment (SRA) determines the probability of finishing on or before a given point in time. This viewgraph presentation introduces the prerequisites, probability distribution curves, special conditions, calculations, and results analysis for SRA.

  7. Distributed network scheduling

    NASA Technical Reports Server (NTRS)

    Clement, Bradley J.; Schaffer, Steven R.

    2005-01-01

    We investigate missions where communications resources are limited, requiring autonomous planning and execution. Unlike typical networks, spacecraft networks are also suited to automated planning and scheduling because many communications can be planned in advance.

  8. Initial Hardware Development Schedule

    NASA Technical Reports Server (NTRS)

    Culpepper, William X.

    1991-01-01

    The hardware development schedule for the Common Lunar Lander's (CLLs) tracking system is presented. Among the topics covered are the following: historical perspective, solution options, industry contacts, and the rationale for selection.

  9. Prototype resupply scheduler

    NASA Technical Reports Server (NTRS)

    Tanner, Steve; Hughes, Angi; Byrd, Jim

    1987-01-01

    Resupply scheduling for the Space Station presents some formidable logistics problems. One of the most basic problems is assigning supplies to a series of shuttle resupply missions. A prototype logistics expert system which constructs resupply schedules was developed. This prototype is able to reconstruct feasible resupply plans. In addition, analysts can use the system to evaluate the impact of adding, deleting or modifying launches, cargo space, experiments, etc.

  10. Tuning for temporal interval in human apparent motion detection.

    PubMed

    Bours, Roger J E; Stuur, Sanne; Lankheet, Martin J M

    2007-01-01

    Detection of apparent motion in random dot patterns requires correlation across time and space. It has been difficult to study the temporal requirements for the correlation step because motion detection also depends on temporal filtering preceding correlation and on integration at the next levels. To specifically study tuning for temporal interval in the correlation step, we performed an experiment in which prefiltering and postintegration were held constant and in which we used a motion stimulus containing coherent motion for a single interval value only. The stimulus consisted of a sparse random dot pattern in which each dot was presented in two frames only, separated by a specified interval. On each frame, half of the dots were refreshed and the other half was a displaced reincarnation of the pattern generated one or several frames earlier. Motion energy statistics in such a stimulus do not vary from frame to frame, and the directional bias in spatiotemporal correlations is similar for different interval settings. We measured coherence thresholds for left-right direction discrimination by varying motion coherence levels in a Quest staircase procedure, as a function of both step size and interval. Results show that highest sensitivity was found for an interval of 17-42 ms, irrespective of viewing distance. The falloff at longer intervals was much sharper than previously described. Tuning for temporal interval was largely, but not completely, independent of step size. The optimal temporal interval slightly decreased with increasing step size. Similarly, the optimal step size decreased with increasing temporal interval. PMID:17461670

  11. Longest queue first scheduled assembly for optical burst switching networks

    NASA Astrophysics Data System (ADS)

    Lu, Zhaobiao; Wang, Hongbo; Zhang, Min; Ye, Peida

    2005-11-01

    Proposed in this paper is a novel burst assembly scheme called longest queue first scheduled assembly (LQF-SA) mechanism, where burst assembly and burst scheduling for optical burst-switching networks are integrated. In the proposed mechanism, ingress edge nodes have multiple assembly queues where IP packets are stored according to their egresses and QoS classes. Among these queues, the longest one is scheduled to assemble bursts by a scheduler at a fixed interval. In real networks, traffic usually distributes non-uniformly and there exists heavier traffic between some source and destination pairs. Simulation results show that LQF-SA could adapt well to the non-uniform traffic profiles. Furthermore, even under uniform traffic, LQF-SA is also super to round-robin scheduled assembly (RR-SA) in terms of burst size distribution, assembly efficiency, and burst loss rate.

  12. Expert systems tools for Hubble Space Telescope observation scheduling

    NASA Technical Reports Server (NTRS)

    Miller, Glenn; Rosenthal, Don; Cohen, William; Johnston, Mark

    1987-01-01

    The utility of expert systems techniques for the Hubble Space Telescope (HST) planning and scheduling is discussed and a plan for development of expert system tools which will augment the existing ground system is described. Additional capabilities provided by these tools will include graphics-oriented plan evaluation, long-range analysis of the observation pool, analysis of optimal scheduling time intervals, constructing sequences of spacecraft activities which minimize operational overhead, and optimization of linkages between observations. Initial prototyping of a scheduler used the Automated Reasoning Tool running on a LISP workstation.

  13. Hypofractionated Versus Conventionally Fractionated Radiotherapy for Prostate Carcinoma: Final Results of Phase III Randomized Trial

    SciTech Connect

    Yeoh, Eric E.; Botten, Rochelle J.; Butters, Julie; Di Matteo, Addolorata C.; Holloway, Richard H.; Fowler, Jack

    2011-12-01

    Purpose: To evaluate the long-term efficacy and toxicity of a hypofractionated (55 Gy in 20 fractions within 4 weeks) vs. a conventionally fractionated (64 Gy in 32 fractions within 6.5 weeks) dose schedule for radiotherapy (RT) for localized carcinoma of the prostate. Methods and Materials: A total of 217 patients were randomized to either the hypofractionated (n = 108) or the conventional (n = 109) dose schedule. Most patients (n = 156) underwent RT planning and RT using a two-dimensional computed tomography method. Efficacy using the clinical, radiologic, and prostate-specific antigen data in each patient was evaluated before RT and at predetermined intervals after RT until death. Gastrointestinal and genitourinary toxicity using the modified Late Effect in Normal Tissue - Subjective Objective Management Analytic (LENT-SOMA) scales was also evaluated before and at intervals after RT to 60 months. Results: The whole group has now been followed for a median of 90 months (range, 3-138). Of the 217 patients, 85 developed biochemical relapse (nadir prostate-specific antigen level + 2 {mu}g/L), 36 in the hypofractionated and 49 in the conventional group. The biochemical relapse-free, but not overall, survival at 90 months was significantly better with the hypofractionated (53%) than with the conventional (34%) schedule. Gastrointestinal and genitourinary toxicity persisted 60 months after RT and did not differ between the two dose schedules. Multivariate analyses revealed that the conventional schedule was of independent prognostic significance, not only for biochemical failure, but also for an increased risk of worse genitourinary symptoms at 4 years. Conclusions: A therapeutic advantage of the hypofractionated compared with the conventional dose schedule for RT of prostate cancer was evident at 90 months in the present study.

  14. Human performance on negative slope schedules of points exchangeable for money: a failure of molar maximization.

    PubMed Central

    Jacobs, E A; Hackenberg, T D

    2000-01-01

    Panel pressing was generated and maintained in 5 adult humans by schedules of points exchangeable for money. Following exposure to a variable-interval 30-s schedule and to a linear variable-interval 30-s schedule (which permitted points to accumulate in an unseen "store" in the absence of responding), subjects were exposed to a series of conditions with a point-subtraction contingency arranged conjointly with the linear variable-interval schedule. Specifically, points were added to the store according to the linear-variable interval 30-s schedule and were subtracted from the store according to a ratio schedule. Ratio value varied across conditions and was determined individually for each subject such that the subtraction contingency would result in an approximately 50% reduction in the rate of point delivery. Conditions that included the subtraction contingency were termed negative slope schedules because the feedback functions were negatively sloped across all response rates greater than the inverse of the variable-interval schedule, in this case, two per minute. Overall response rates varied inversely with the subtraction ratio, indicating sensitivity to the negative slope conditions, but were in excess of that required by accounts based on strict maximization of overall reinforcement rate. Performance was also not well described by a matching-based account. Detailed analyses of response patterning revealed a consistent two-state pattern in which bursts of high-rate responding alternated with periods of prolonged pausing, perhaps reflecting the joint influence of local and overall reinforcement rates. PMID:10866350

  15. Experimenting with musical intervals

    NASA Astrophysics Data System (ADS)

    Lo Presto, Michael C.

    2003-07-01

    When two tuning forks of different frequency are sounded simultaneously the result is a complex wave with a repetition frequency that is the fundamental of the harmonic series to which both frequencies belong. The ear perceives this 'musical interval' as a single musical pitch with a sound quality produced by the harmonic spectrum responsible for the waveform. This waveform can be captured and displayed with data collection hardware and software. The fundamental frequency can then be calculated and compared with what would be expected from the frequencies of the tuning forks. Also, graphing software can be used to determine equations for the waveforms and predict their shapes. This experiment could be used in an introductory physics or musical acoustics course as a practical lesson in superposition of waves, basic Fourier series and the relationship between some of the ear's subjective perceptions of sound and the physical properties of the waves that cause them.

  16. Knowledge based tools for Hubble Space Telescope planning and scheduling: Constraints and strategies

    NASA Technical Reports Server (NTRS)

    Miller, Glenn; Johnston, Mark; Vick, Shon; Sponsler, Jeff; Lindenmayer, Kelly

    1988-01-01

    The Hubble Space Telescope (HST) presents an especially challenging scheduling problem since a year's observing program encompasses tens of thousands of exposures facing numerous coupled constraints. Recent progress in the development of planning and scheduling tools is discussed which augment the existing HST ground system. General methods for representing activities, constraints, and constraint satisfaction, and time segmentation were implemented in a scheduling testbed. The testbed permits planners to evaluate optimal scheduling time intervals, calculate resource usage, and to generate long and medium range plans. Graphical displays of activities, constraints, and plans are an important feature of the system. High-level scheduling strategies using rule based and neural net approaches were implemented.

  17. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocations for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its applications to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  18. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  19. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1993-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  20. SPANR planning and scheduling

    NASA Astrophysics Data System (ADS)

    Freund, Richard F.; Braun, Tracy D.; Kussow, Matthew; Godfrey, Michael; Koyama, Terry

    2001-07-01

    SPANR (Schedule, Plan, Assess Networked Resources) is (i) a pre-run, off-line planning and (ii) a runtime, just-in-time scheduling mechanism. It is designed to support primarily commercial applications in that it optimizes throughput rather than individual jobs (unless they have highest priority). Thus it is a tool for a commercial production manager to maximize total work. First the SPANR Planner is presented showing the ability to do predictive 'what-if' planning. It can answer such questions as, (i) what is the overall effect of acquiring new hardware or (ii) what would be the effect of a different scheduler. The ability of the SPANR Planner to formulate in advance tree-trimming strategies is useful in several commercial applications, such as electronic design or pharmaceutical simulations. The SPANR Planner is demonstrated using a variety of benchmarks. The SPANR Runtime Scheduler (RS) is briefly presented. The SPANR RS can provide benefit for several commercial applications, such as airframe design and financial applications. Finally a design is shown whereby SPANR can provide scheduling advice to most resource management systems.

  1. Automated Scheduling Via Artificial Intelligence

    NASA Technical Reports Server (NTRS)

    Biefeld, Eric W.; Cooper, Lynne P.

    1991-01-01

    Artificial-intelligence software that automates scheduling developed in Operations Mission Planner (OMP) research project. Software used in both generation of new schedules and modification of existing schedules in view of changes in tasks and/or available resources. Approach based on iterative refinement. Although project focused upon scheduling of operations of scientific instruments and other equipment aboard spacecraft, also applicable to such terrestrial problems as scheduling production in factory.

  2. Schedule-Tracker Computer Program

    NASA Technical Reports Server (NTRS)

    Collazo, Fernando F.

    1990-01-01

    Schedule Tracker provides effective method for tracking tasks "past due" and/or "near term". Generates reports for each responsible staff member having one or more assigned tasks falling within two listed categories. Schedule Organizer (SO) (COSMIC program MSC-21525), Schedule Tracker (ST), and Schedule Report Generator (SRG) (COSMIC program MSC-21527) computer programs manipulating data-base files in ways advantageous in scheduling. Written in PL/1 and DEC Command Language (DCL).

  3. Scheduling with Automatic Resolution of Conflicts

    NASA Technical Reports Server (NTRS)

    Clement, Bradley; Schaffer, Steve

    2006-01-01

    DSN Requirement Scheduler is a computer program that automatically schedules, reschedules, and resolves conflicts for allocations of resources of NASA s Deep Space Network (DSN) on the basis of ever-changing project requirements for DSN services. As used here, resources signifies, primarily, DSN antennas, ancillary equipment, and times during which they are available. Examples of project-required DSN services include arraying, segmentation, very-long-baseline interferometry, and multiple spacecraft per aperture. Requirements can include periodic reservations of specific or optional resources during specific time intervals or within ranges specified in terms of starting times and durations. This program is built on the Automated Scheduling and Planning Environment (ASPEN) software system (aspects of which have been described in previous NASA Tech Briefs articles), with customization to reflect requirements and constraints involved in allocation of DSN resources. Unlike prior DSN-resource- scheduling programs that make single passes through the requirements and require human intervention to resolve conflicts, this program makes repeated passes in a continuing search for all possible allocations, provides a best-effort solution at any time, and presents alternative solutions among which users can choose.

  4. Rapid shift in sleep time and acrophase of melatonin secretion in short shift work schedule.

    PubMed

    Quera-Salva, M A; Defrance, R; Claustrat, B; De Lattre, J; Guilleminault, C

    1996-09-01

    Tolerance to shift work and adaptability to shifting schedules is an issue of growing importance in industrialized society. We studied 40 registered nurses, 20 on fixed day-shifts and 20 on fixed night-shifts, to assess whether workers with rapidly shifting schedules were able to adapt their melatonin secretion and sleep-wake cycles. The day-shift worked 5 days with 2 days off and the night-shift worked 3 nights with 2 off. All night-shift personnel acknowledged shifting back to daytime schedules on their days off. Sleep-wake was determined by sleep logs and actigraphy. To measure 6-sulfatoxymelatonin levels, urine was collected at 2-hour intervals on the last work day and on the last day off. Night-shift workers slept significantly more on days off. Napping on the job occurred in 9/20 night-shift workers (mean 114 minutes) between 3 and 6 a.m. The acrophase of 6-sulfatoxymelatonin in day-shift nurses occurred at similar times on workdays and off days. In night-shift nurses, the acrophase was about 7 a.m. on days off, but had a random distribution on workdays. Further analysis revealed two subgroups of night-shift nurses: six subjects (group A).demonstrated a rapid shift in melatonin secretion (acrophase at near 12 noon on work days and at near 7 a.m. on days off) while 14 nurses (group B) did not shift. Group A nurses slept more in the daytime on work days and their total sleep time was the same as day-shift nurses. Group A was slightly younger and was composed solely of women (there were nine women and five men in group B). Age may be a factor in the ability to adapt to rapidly shifting schedules. PMID:8899932

  5. Scheduling with genetic algorithms

    NASA Technical Reports Server (NTRS)

    Fennel, Theron R.; Underbrink, A. J., Jr.; Williams, George P. W., Jr.

    1994-01-01

    In many domains, scheduling a sequence of jobs is an important function contributing to the overall efficiency of the operation. At Boeing, we develop schedules for many different domains, including assembly of military and commercial aircraft, weapons systems, and space vehicles. Boeing is under contract to develop scheduling systems for the Space Station Payload Planning System (PPS) and Payload Operations and Integration Center (POIC). These applications require that we respect certain sequencing restrictions among the jobs to be scheduled while at the same time assigning resources to the jobs. We call this general problem scheduling and resource allocation. Genetic algorithms (GA's) offer a search method that uses a population of solutions and benefits from intrinsic parallelism to search the problem space rapidly, producing near-optimal solutions. Good intermediate solutions are probabalistically recombined to produce better offspring (based upon some application specific measure of solution fitness, e.g., minimum flowtime, or schedule completeness). Also, at any point in the search, any intermediate solution can be accepted as a final solution; allowing the search to proceed longer usually produces a better solution while terminating the search at virtually any time may yield an acceptable solution. Many processes are constrained by restrictions of sequence among the individual jobs. For a specific job, other jobs must be completed beforehand. While there are obviously many other constraints on processes, it is these on which we focussed for this research: how to allocate crews to jobs while satisfying job precedence requirements and personnel, and tooling and fixture (or, more generally, resource) requirements.

  6. Approximation Schemes for Scheduling with Availability Constraints

    NASA Astrophysics Data System (ADS)

    Fu, Bin; Huo, Yumei; Zhao, Hairong

    We investigate the problems of scheduling n weighted jobs to m identical machines with availability constraints. We consider two different models of availability constraints: the preventive model where the unavailability is due to preventive machine maintenance, and the fixed job model where the unavailability is due to a priori assignment of some of the n jobs to certain machines at certain times. Both models have applications such as turnaround scheduling or overlay computing. In both models, the objective is to minimize the total weighted completion time. We assume that m is a constant, and the jobs are non-resumable. For the preventive model, it has been shown that there is no approximation algorithm if all machines have unavailable intervals even when w i = p i for all jobs. In this paper, we assume there is one machine permanently available and the processing time of each job is equal to its weight for all jobs. We develop the first PTAS when there are constant number of unavailable intervals. One main feature of our algorithm is that the classification of large and small jobs is with respect to each individual interval, thus not fixed. This classification allows us (1) to enumerate the assignments of large jobs efficiently; (2) and to move small jobs around without increasing the objective value too much, and thus derive our PTAS. Then we show that there is no FPTAS in this case unless P = NP.

  7. NASA revises shuttle schedule

    NASA Astrophysics Data System (ADS)

    Wainger, Lisa A.

    The new schedule for Space Shuttle missions and expendable launch vehicles (ELV's) calls for a 7-month delay in sending up the Hubble Space Telescope. NASA was forced to put off launching the telescope until February 1990 to keep the Magellan and Galileo missions within their narrow launch windows. The first post-Challenger shuttle launch is now scheduled for late this month. Discovery's most recent delays were due to a hydrogen leak discovered July 29 that has still not been corrected and an engine valve malfunction during an August 4 test fire.

  8. Intelligent retail logistics scheduling

    SciTech Connect

    Rowe, J.; Jewers, K.; Codd, A.; Alcock, A.

    1996-12-31

    The Supply Chain Integrated Ordering Network (SCION) Depot Bookings system automates the planning and scheduling of perishable and non-perishable commodities and the vehicles that carry them into J. Sainsbury depots. This is a strategic initiative, enabling the business to make the key move from weekly to daily ordering. The system is mission critical, managing the inwards flow of commodities from suppliers into J. Sainsbury`s depots. The system leverages Al techniques to provide a business solution that meets challenging functional and performance needs. The SCION Depot Bookings system is operational providing schedules for 22 depots across the UK.

  9. Multiple daily fractionation schedules

    SciTech Connect

    Peschel, R.E.; Fischer, J.J.

    1982-10-01

    Although conventional fractionation schedules have been satisfactory for the treatment of some tumors, there is reason to believe that the results of radiation therapy could be improved in some cases by appropriate alterations in treatment schedules. The pharmacological characteristics of some of the electron affinic radiation sensitizers have provided added incentive to investigate newer fractionation schemes, particularly ones which deliver the majority of the radiation dose in short periods of time. This editorial discusses three papers describing preliminary clinical studies using multi-daily fractionated (MDF) radiation therapy. Two of these studies also make use of the radiation sensitizer misonidazole. (KRM)

  10. Department of Defense Precise Time and Time Interval program improvement plan

    NASA Technical Reports Server (NTRS)

    Bowser, J. R.

    1981-01-01

    The United States Naval Observatory is responsible for ensuring uniformity in precise time and time interval operations including measurements, the establishment of overall DOD requirements for time and time interval, and the accomplishment of objectives requiring precise time and time interval with minimum cost. An overview of the objectives, the approach to the problem, the schedule, and a status report, including significant findings relative to organizational relationships, current directives, principal PTTI users, and future requirements as currently identified by the users are presented.

  11. Effect of Dexmedetomidine on Heart Rate-Corrected QT and Tpeak–Tend Intervals During Robot-Assisted Laparoscopic Prostatectomy With Steep Trendelenburg Position

    PubMed Central

    Kim, Na Young; Han, Dong Woo; Koh, Jae Chul; Rha, Koon Ho; Hong, Jung Hwa; Park, Jong Min; Kim, So Yeon

    2016-01-01

    Abstract Intraperitoneal insufflation of carbon dioxide may affect the sympathetic activity that leads to changes in ventricular repolarization. This in turn can result in changes of heart rate-corrected QT (QTc) interval and Tpeak–Tend (Tp-e) interval. Dexmedetomidine is a highly selective α2-receptor agonist and has potential antiarrhythmic properties. This prospective, randomized, double-blinded, controlled study evaluated the effects of dexmedetomidine administration on QTc and Tp-e intervals during robot-assisted laparoscopic prostatectomy with steep Trendelenburg position. Fifty patients scheduled for robot-assisted laparoscopic prostatectomy randomly received either a continuous infusion of dexmedetomidine at a rate of 0.3 μg/kg/hour, from anesthetic induction until the end of the Trendelenburg position (dexmedetomidine group; n = 25), or the same volume of normal saline (control group; n = 25). Anesthesia was maintained with sevoflurane and remifentanil. The primary and secondary goals were to evaluate the effect of dexmedetomidine on the QTc and Tp-e interval changes. Mean arterial pressure, heart rate, end-tidal CO2, and end-tidal sevoflurane concentrations were assessed as well. Forty-seven patients (94%) completed the study. Dexmedetomidine significantly attenuated QTc interval prolongation and reduced the Tp-e interval, even though the baseline values of the QTc and Tp-e intervals were similar between the 2 groups (PGroup × Time = 0.001 and 0.014, respectively). Twenty-two patients (96%) in the control group and 13 (54%) in the dexmedetomidine group had QTc interval prolongation of >20 ms from the baseline value during surgery (P = 0.001). The maximum QTc interval prolongation from the baseline value during surgery was 46 ± 21 ms in the control group and 24 ± 21 ms in the dexmedetomidine group (mean ± SD, P = 0.001). Mean arterial pressure and heart rate were comparable between the groups. Continuous

  12. Steps Toward Optimal Competitive Scheduling

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Crawford, James; Khatib, Lina; Brafman, Ronen

    2006-01-01

    This paper is concerned with the problem of allocating a unit capacity resource to multiple users within a pre-defined time period. The resource is indivisible, so that at most one user can use it at each time instance. However, different users may use it at different times. The users have independent, se@sh preferences for when and for how long they are allocated this resource. Thus, they value different resource access durations differently, and they value different time slots differently. We seek an optimal allocation schedule for this resource. This problem arises in many institutional settings where, e.g., different departments, agencies, or personal, compete for a single resource. We are particularly motivated by the problem of scheduling NASA's Deep Space Satellite Network (DSN) among different users within NASA. Access to DSN is needed for transmitting data from various space missions to Earth. Each mission has different needs for DSN time, depending on satellite and planetary orbits. Typically, the DSN is over-subscribed, in that not all missions will be allocated as much time as they want. This leads to various inefficiencies - missions spend much time and resource lobbying for their time, often exaggerating their needs. NASA, on the other hand, would like to make optimal use of this resource, ensuring that the good for NASA is maximized. This raises the thorny problem of how to measure the utility to NASA of each allocation. In the typical case, it is difficult for the central agency, NASA in our case, to assess the value of each interval to each user - this is really only known to the users who understand their needs. Thus, our problem is more precisely formulated as follows: find an allocation schedule for the resource that maximizes the sum of users preferences, when the preference values are private information of the users. We bypass this problem by making the assumptions that one can assign money to customers. This assumption is reasonable; a

  13. Control of Angular Intervals for Angle-Multiplexed Holographic Memory

    NASA Astrophysics Data System (ADS)

    Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki

    2009-03-01

    In angle-multiplexed holographic memory, the full width at half maximum of the Bragg selectivity curves is dependent on the angle formed between the medium and incident laser beams. This indicates the possibility of high density and high multiplexing number by varying the angular intervals between adjacent holograms. We propose an angular interval scheduling for closely stacking holograms into medium even when the angle range is limited. We obtained bit error rates of the order of 10-4 under the following conditions: medium thickness of 1 mm, laser beam wavelength of 532 nm, and angular multiplexing number of 300.

  14. A Component Analysis of Schedule Thinning during Functional Communication Training

    ERIC Educational Resources Information Center

    Betz, Alison M.; Fisher, Wayne W.; Roane, Henry S.; Mintz, Joslyn C.; Owen, Todd M.

    2013-01-01

    One limitation of functional communication training (FCT) is that individuals may request reinforcement via the functional communication response (FCR) at exceedingly high rates. Multiple schedules with alternating periods of reinforcement and extinction of the FCR combined with gradually lengthening the extinction-component interval can…

  15. Concurrent-schedule performance in dairy cows: persistent undermatching.

    PubMed

    Foster, T M; Temple, W; Robertson, B; Nair, V; Poling, A

    1996-01-01

    Performance of dairy cows responding under concurrent variable-interval variable-interval schedules of food delivery was examined, with results analyzed in terms of the generalized matching equation. In Experiment 1, bias measures indicated that crushed barley was preferred over meatmeal when these foods were available under the alternative schedules. For whole-session data, substantial undermatching of response and time-allocation ratios to obtained reinforcement ratios was evident. Postreinforcement pause time ratios approximately matched obtained reinforcement rates. Subtracting these times from total time-allocation values yielded net time-allocation ratios that undermatched obtained reinforcement ratios to a greater degree than did whole-session time-allocation ratios. In Experiment 2, substantial undermatching was evident when the same foods (hay for 2 cows, crushed barley for 2 others) were available under the alternative schedules. Food-related activities and other defined behavior not related to food were quantified by direct observation, and were found to occupy a substantial proportion (roughly 40% to 80%) of experimental sessions. Subtracting the time spent in these activities from the time allocated to each component schedule did not reduce the degree of undermatching obtained. Across all conditions in both experiments, slopes of regression lines relating behavioral outputs to environmental inputs characteristically were below 0.6, which agrees with prior findings and suggests that, contrary to suggestions in the literature, undermatching in dairy cows is not the result of using different foods under alternative schedules or differential pausing under those schedules. PMID:8583205

  16. "Creative" Work Schedules.

    ERIC Educational Resources Information Center

    Blai, Boris

    Many creative or flexible work scheduling options are becoming available to the many working parents, students, handicapped persons, elderly individuals, and others who are either unable or unwilling to work a customary 40-hour work week. These options may be broadly categorized as either restructured or reduced work time options. The three main…

  17. Parent Interview Schedule.

    ERIC Educational Resources Information Center

    Purdue Univ., Lafayette, IN. Educational Research Center.

    This 116-item interview schedule designed for parents who failed to respond to the Questionnaire for Parents, is individually administered to the mother of the child of elementary school age. It consists of scales measuring 14 parent variables plus a section devoted to demographic variables: (1) parent's achievement aspirations for the child, (2)…

  18. CMS multicore scheduling strategy

    SciTech Connect

    Perez-Calero Yzquierdo, Antonio; Hernandez, Jose; Holzman, Burt; Majewski, Krista; McCrea, Alison

    2014-01-01

    In the next years, processor architectures based on much larger numbers of cores will be most likely the model to continue 'Moore's Law' style throughput gains. This not only results in many more jobs in parallel running the LHC Run 1 era monolithic applications, but also the memory requirements of these processes push the workernode architectures to the limit. One solution is parallelizing the application itself, through forking and memory sharing or through threaded frameworks. CMS is following all of these approaches and has a comprehensive strategy to schedule multicore jobs on the GRID based on the glideinWMS submission infrastructure. The main component of the scheduling strategy, a pilot-based model with dynamic partitioning of resources that allows the transition to multicore or whole-node scheduling without disallowing the use of single-core jobs, is described. This contribution also presents the experiences made with the proposed multicore scheduling schema and gives an outlook of further developments working towards the restart of the LHC in 2015.

  19. CMS multicore scheduling strategy

    NASA Astrophysics Data System (ADS)

    Pérez-Calero Yzquierdo, Antonio; Hernández, Jose; Holzman, Burt; Majewski, Krista; McCrea, Alison; Cms Collaboration

    2014-06-01

    In the next years, processor architectures based on much larger numbers of cores will be most likely the model to continue "Moore's Law" style throughput gains. This not only results in many more jobs in parallel running the LHC Run 1 era monolithic applications, but also the memory requirements of these processes push the workernode architectures to the limit. One solution is parallelizing the application itself, through forking and memory sharing or through threaded frameworks. CMS is following all of these approaches and has a comprehensive strategy to schedule multicore jobs on the GRID based on the glideinWMS submission infrastructure. The main component of the scheduling strategy, a pilot-based model with dynamic partitioning of resources that allows the transition to multicore or whole-node scheduling without disallowing the use of single-core jobs, is described. This contribution also presents the experiences made with the proposed multicore scheduling schema and gives an outlook of further developments working towards the restart of the LHC in 2015.

  20. Schedule-Induced Stereotypy.

    ERIC Educational Resources Information Center

    Emerson, Eric; Howard, Denise

    1992-01-01

    The phenomena of the induction and entrainment of adjunctive behaviors was investigated in 8 people (ages 5-51) with severe or profound mental retardation who exhibited stereotypic behaviors. Seven of the eight demonstrated evidence of schedule-induced stereotypic behavior, whereas five also showed evidence of the entrainment of these behaviors by…

  1. Enhanced decomposition algorithm for multistage stochastic hydroelectric scheduling. Technical report

    SciTech Connect

    Morton, D.P.

    1994-01-01

    Handling uncertainty in natural inflow is an important part of a hydroelectric scheduling model. In a stochastic programming formulation, natural inflow may be modeled as a random vector with known distribution, but the size of the resulting mathematical program can be formidable. Decomposition-based algorithms take advantage of special structure and provide an attractive approach to such problems. We develop an enhanced Benders decomposition algorithm for solving multistage stochastic linear programs. The enhancements include warm start basis selection, preliminary cut generation, the multicut procedure, and decision tree traversing strategies. Computational results are presented for a collection of stochastic hydroelectric scheduling problems. Stochastic programming, Hydroelectric scheduling, Large-scale Systems.

  2. The Isolation of Motivational, Motoric, and Schedule Effects on Operant Performance: A Modeling Approach

    ERIC Educational Resources Information Center

    Brackney, Ryan J.; Cheung, Timothy H. C.; Neisewander, Janet L.; Sanabria, Federico

    2011-01-01

    Dissociating motoric and motivational effects of pharmacological manipulations on operant behavior is a substantial challenge. To address this problem, we applied a response-bout analysis to data from rats trained to lever press for sucrose on variable-interval (VI) schedules of reinforcement. Motoric, motivational, and schedule factors (effort…

  3. Choice between Single and Multiple Reinforcers in Concurrent-Chains Schedules

    ERIC Educational Resources Information Center

    Mazur, James E.

    2006-01-01

    Pigeons responded on concurrent-chains schedules with equal variable-interval schedules as initial links. One terminal link delivered a single reinforcer after a fixed delay, and the other terminal link delivered either three or five reinforcers, each preceded by a fixed delay. Some conditions included a postreinforcer delay after the single…

  4. Impaired Behavior Regulation under Conditions of Concurrent Variable Schedules of Reinforcement in Children with ADHD

    ERIC Educational Resources Information Center

    Taylor, David; Lincoln, Alan J.; Foster, Sharon L.

    2010-01-01

    Objective: To bridge theory of response inhibition and learning in children with ADHD. Method: Thirty ADHD and 30 non-ADHD children (ages 9-12) were compared under concurrent variable interval (VI-15 sec., VI-30 sec. and VI- 45 sec.) reinforcement schedules that required the child to switch between the three schedules under conditions of…

  5. SOLTI NeoPARP: a phase II randomized study of two schedules of iniparib plus paclitaxel versus paclitaxel alone as neoadjuvant therapy in patients with triple-negative breast cancer.

    PubMed

    Llombart-Cussac, Antonio; Bermejo, Begoña; Villanueva, Cristian; Delaloge, Suzette; Morales, Serafín; Balmaña, Judith; Amillano, Kepa; Bonnefoi, Hervé; Casas, Ana; Manso, Luis; Roché, Henri; Gonzalez-Santiago, Santiago; Gavilá, Joaquín; Sánchez-Rovira, Pedro; Di Cosimo, Serena; Harbeck, Nadia; Charpentier, Eric; Garcia-Ribas, Ignacio; Radosevic-Robin, Nina; Aura, Claudia; Baselga, Jose

    2015-11-01

    Iniparib is an investigational agent with antitumor activity of controversial mechanism of action. Two previous trials in advanced triple-negative breast cancer (TNBC) in combination with gemcitabine and carboplatin showed some evidence of efficacy that was not confirmed. This phase II randomized neoadjuvant study was designed to explore its activity and tolerability with weekly paclitaxel (PTX) as neoadjuvant treatment in TNBC patients. 141 patients with Stage II-IIIA TNBC were randomly assigned to receive PTX (80 mg/m(2), d1; n = 47) alone or in combination with iniparib, either once-weekly (PWI) (11.2 mg/kg, d1; n = 46) or twice-weekly (PTI) (5.6 mg/kg, d1, 4; n = 48) for 12 weeks. Primary endpoint was pathologic complete response (pCR) in the breast. pCR rate was similar among the three arms (21, 22, and 19 % for PTX, PWI, and PTI, respectively). Secondary efficacy endpoints were comparable: pCR in breast and axilla (21, 17, and 19 %); best overall response in the breast (60, 61, and 63 %); and breast conservation rate (53, 54, and 50 %). Slightly more patients in the PTI arm presented grade 3/4 neutropenia (4, 0, and 10 %). Grade 1/2 (28, 22, and 29 %), but no grade 3/4 neuropathy, was observed. There were no differences in serious adverse events and treatment-emergent adverse events leading to treatment discontinuation among the three arms. Addition of iniparib to weekly PTX did not add relevant antitumor activity or toxicity. These results do not support further evaluation of the combination of iniparib at these doses plus paclitaxel in early TNBC. PMID:26536871

  6. An interval model updating strategy using interval response surface models

    NASA Astrophysics Data System (ADS)

    Fang, Sheng-En; Zhang, Qiu-Hu; Ren, Wei-Xin

    2015-08-01

    Stochastic model updating provides an effective way of handling uncertainties existing in real-world structures. In general, probabilistic theories, fuzzy mathematics or interval analyses are involved in the solution of inverse problems. However in practice, probability distributions or membership functions of structural parameters are often unavailable due to insufficient information of a structure. At this moment an interval model updating procedure shows its superiority in the aspect of problem simplification since only the upper and lower bounds of parameters and responses are sought. To this end, this study develops a new concept of interval response surface models for the purpose of efficiently implementing the interval model updating procedure. The frequent interval overestimation due to the use of interval arithmetic can be maximally avoided leading to accurate estimation of parameter intervals. Meanwhile, the establishment of an interval inverse problem is highly simplified, accompanied by a saving of computational costs. By this means a relatively simple and cost-efficient interval updating process can be achieved. Lastly, the feasibility and reliability of the developed method have been verified against a numerical mass-spring system and also against a set of experimentally tested steel plates.

  7. Effects of diazepam on schedule-controlled and schedule-induced behavior under signaled and unsignaled shock.

    PubMed Central

    Hymowitz, N

    1981-01-01

    Schedule-controlled lever pressing and schedule-induced licking were studied in rats under a multiple fixed-interval fixed-interval schedule of food reinforcement upon which was superimposed a multiple variable-time variable-time schedule of electric-shock delivery. Shocks were signaled in one component of the multiple schedule and unsignaled in the other. The effects of diazepam upon the suppression of behavior during the signal (conditioned suppression) and during signaled and unsignaled shock (differential suppression) were studied under several shock intensities (Experiment 1) and at increased body weight (Experiment 2). In each study, diazepam led to dose-dependent increases in the rate of pressing and licking during signaled and unsignaled shock, but had little effect on conditioned suppression. the rate-enhancing effects of diazepam depended upon the intensity of shock, nature of the response, and whether or not shocks were signaled. The data was discussed in terms of (1) implications for understanding the effects of signaled and unsignaled shock on behavior, (2) the effects of diazepam on behavior suppressed by response-independent shock, and (3) comparison between operant and schedule-induced behavior. PMID:7241035

  8. Planning and Scheduling for Environmental Sensor Networks

    NASA Astrophysics Data System (ADS)

    Frank, J. D.

    2005-12-01

    resources and to reduce the costs of communication. Planning and scheduling is generally a heavy consumer of time, memory and energy resources. This means careful thought must be given to how much planning and scheduling should be done on the sensors themselves, and how much to do elsewhere. The difficulty of planning and scheduling is exacerbated when reasoning about uncertainty. More time, memory and energy is needed to solve such problems, leading either to more expensive sensors, or suboptimal plans. For example, scientifically interesting events may happen at random times, making it difficult to ensure that sufficient resources are availanble. Since uncertainty is usually lowest in proximity to the sensors themselves, this argues for planning and scheduling onboard the sensors. However, cost minimization dictates sensors be kept as simple as possible, reducing the amount of planning and scheduling they can do themselves. Furthermore, coordinating each sensor's independent plans can be difficult. In the full presentation, we will critically review the planning and scheduling systems used by previously fielded sensor networks. We do so primarily from the perspective of the computational sciences, with a focus on taming computational complexity when operating sensor networks. The case studies are derived from sensor networks based on UAVs, satellites, and planetary rovers. Planning and scheduling considerations include multi-sensor coordination, optimizing science value, onboard power management, onboard memory, planning movement actions to acquire data, and managing communications.These case studies offer lessons for future designs of environmental sensor networks.

  9. Completable scheduling: An integrated approach to planning and scheduling

    NASA Technical Reports Server (NTRS)

    Gervasio, Melinda T.; Dejong, Gerald F.

    1992-01-01

    The planning problem has traditionally been treated separately from the scheduling problem. However, as more realistic domains are tackled, it becomes evident that the problem of deciding on an ordered set of tasks to achieve a set of goals cannot be treated independently of the problem of actually allocating resources to the tasks. Doing so would result in losing the robustness and flexibility needed to deal with imperfectly modeled domains. Completable scheduling is an approach which integrates the two problems by allowing an a priori planning module to defer particular planning decisions, and consequently the associated scheduling decisions, until execution time. This allows a completable scheduling system to maximize plan flexibility by allowing runtime information to be taken into consideration when making planning and scheduling decision. Furthermore, through the criteria of achievability placed on deferred decision, a completable scheduling system is able to retain much of the goal-directedness and guarantees of achievement afforded by a priori planning. The completable scheduling approach is further enhanced by the use of contingent explanation-based learning, which enables a completable scheduling system to learn general completable plans from example and improve its performance through experience. Initial experimental results show that completable scheduling outperforms classical scheduling as well as pure reactive scheduling in a simple scheduling domain.

  10. Scheduling techniques in the Request Oriented Scheduling Engine (ROSE)

    NASA Technical Reports Server (NTRS)

    Zoch, David R.

    1991-01-01

    Scheduling techniques in the ROSE are presented in the form of the viewgraphs. The following subject areas are covered: agenda; ROSE summary and history; NCC-ROSE task goals; accomplishments; ROSE timeline manager; scheduling concerns; current and ROSE approaches; initial scheduling; BFSSE overview and example; and summary.