Science.gov

Sample records for analysis based control

  1. Knowledge-Based System Analysis and Control

    DTIC Science & Technology

    1989-09-30

    for use as a training tool (given considerable enlargement of its present circuit data base and problem repertoire), because it can provide step-by...from the slow and expensive process of training personnel in complex professional specialties. Tech Control began to emerge as a skill area ripe for...for any purpose but offline training . In late FY87 and early FY88, planning was therefore begun for a new expert system which would have no air gap

  2. Controller design based on μ analysis and PSO algorithm.

    PubMed

    Lari, Ali; Khosravi, Alireza; Rajabi, Farshad

    2014-03-01

    In this paper an evolutionary algorithm is employed to address the controller design problem based on μ analysis. Conventional solutions to μ synthesis problem such as D-K iteration method often lead to high order, impractical controllers. In the proposed approach, a constrained optimization problem based on μ analysis is defined and then an evolutionary approach is employed to solve the optimization problem. The goal is to achieve a more practical controller with lower order. A benchmark system named two-tank system is considered to evaluate performance of the proposed approach. Simulation results show that the proposed controller performs more effective than high order H(∞) controller and has close responses to the high order D-K iteration controller as the common solution to μ synthesis problem. © 2013 ISA Published by ISA All rights reserved.

  3. Control volume based hydrocephalus research; analysis of human data

    NASA Astrophysics Data System (ADS)

    Cohen, Benjamin; Wei, Timothy; Voorhees, Abram; Madsen, Joseph; Anor, Tomer

    2010-11-01

    Hydrocephalus is a neuropathophysiological disorder primarily diagnosed by increased cerebrospinal fluid volume and pressure within the brain. To date, utilization of clinical measurements have been limited to understanding of the relative amplitude and timing of flow, volume and pressure waveforms; qualitative approaches without a clear framework for meaningful quantitative comparison. Pressure volume models and electric circuit analogs enforce volume conservation principles in terms of pressure. Control volume analysis, through the integral mass and momentum conservation equations, ensures that pressure and volume are accounted for using first principles fluid physics. This approach is able to directly incorporate the diverse measurements obtained by clinicians into a simple, direct and robust mechanics based framework. Clinical data obtained for analysis are discussed along with data processing techniques used to extract terms in the conservation equation. Control volume analysis provides a non-invasive, physics-based approach to extracting pressure information from magnetic resonance velocity data that cannot be measured directly by pressure instrumentation.

  4. Analysis the robustness of control systems based on disturbance observer

    NASA Astrophysics Data System (ADS)

    Sariyildiz, Emre; Ohnishi, Kouhei

    2013-10-01

    Disturbance observer (DOB) estimates the system disturbances by using the inverse of the nominal plant model and a low pass filter (LPF). Although the LPF provides the properness in the inner-loop, it is the main design constraint of the control systems based on DOB. The bandwidth of the LPF is designed as high as possible so that the DOB can estimate the disturbances in a wider frequency range. However, its bandwidth is limited by noise and robustness of the system. The robustness limitation is directly related with the robustness analysis methods, and they significantly affect the performance of the DOB based control systems. In this paper, three different robustness analysis methods are implemented into the DOB based control systems, and the relation between the robustness of the system and bandwidth of DOB is clearly explained. The conservatism, which is the main drawback of the conventional analysis methods, on the bandwidth of DOB is removed by proposing a new real parametric uncertainty based analysis method. The proposed methods are compared in detail, and simulation results are given to show the validation.

  5. Knowledge based systems: From process control to policy analysis

    SciTech Connect

    Marinuzzi, J.G.

    1993-06-01

    Los Alamos has been pursuing the use of Knowledge Based Systems for many years. These systems are currently being used to support projects that range across many production and operations areas. By investing time and money in people and equipment, Los Alamos has developed one of the strongest knowledge based systems capabilities within the DOE. Staff of Los Alamos` Mechanical & Electronic Engineering Division are using these knowledge systems to increase capability, productivity and competitiveness in areas of manufacturing quality control, robotics, process control, plant design and management decision support. This paper describes some of these projects and associated technical program approaches, accomplishments, benefits and future goals.

  6. Knowledge based systems: From process control to policy analysis

    SciTech Connect

    Marinuzzi, J.G.

    1993-01-01

    Los Alamos has been pursuing the use of Knowledge Based Systems for many years. These systems are currently being used to support projects that range across many production and operations areas. By investing time and money in people and equipment, Los Alamos has developed one of the strongest knowledge based systems capabilities within the DOE. Staff of Los Alamos' Mechanical Electronic Engineering Division are using these knowledge systems to increase capability, productivity and competitiveness in areas of manufacturing quality control, robotics, process control, plant design and management decision support. This paper describes some of these projects and associated technical program approaches, accomplishments, benefits and future goals.

  7. Intelligent Control in Automation Based on Wireless Traffic Analysis

    SciTech Connect

    Kurt Derr; Milos Manic

    2007-08-01

    Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

  8. Intelligent Control in Automation Based on Wireless Traffic Analysis

    SciTech Connect

    Kurt Derr; Milos Manic

    2007-09-01

    Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

  9. Nonlinear system controller design based on domain of attaction: An application to CELSS analysis and control

    NASA Technical Reports Server (NTRS)

    Babcock, P. S., IV

    1986-01-01

    Nonlinear system controller design based on the domain of attraction is presented. This is particularly suited to investigating Closed Ecological Life Support Systems (CELSS) models. In particular, the dynamic consequences of changes in the waste storage capacity and system mass, and how information is used for control in CELSS models are examined. The models' high dimensionality and nonlinear state equations make them difficult to analyze by any other technique. The domain of attraction is the region in initial conditions that tend toward an attractor and it is delineated by randomly selecting initial conditions from the region of state space being investigated. Error analysis is done by repeating the domain simulations with independent samples. A refinement of this region is the domain of performance which is the region of initial conditions meeting a performance criteria. In nonlinear systems, local stability does not insure stability over a larger region. The domain of attraction marks out this stability region; hence, it can be considered a measure of a nonlinear system's ability to recovery from state perturbations. Considering random perturbations, the minimum radius of the domain is a measure of the magnitude of perturbations for which recovery is guaranteed. Design of both linear and nonlinear controllers are shown. Three CELSS models, with 9 to 30 state variable, are presented. Measures of the domain of attraction are used to show the global behavior of these models under a variety of design and controller scenarios.

  10. Analysis of Information Systems Based on Automatic Control Theory,

    DTIC Science & Technology

    The development of information systems in the USSR have given rise to increased interest in studing them. In this report basic attention is given...to the problems of optimizing the operation and control of information systems . It appears that this problem can be solved most fruitfully on the basis

  11. Computational Analysis for Roughness-Based Transition Control

    NASA Technical Reports Server (NTRS)

    Li, Fei; Choudhari, Meelan M.; Chang, Chau-Lyan; Edwards, Jack R., Jr.

    2009-01-01

    Suitably placed discrete roughness elements are known to delay or hasten the onset of transition, depending on requirements. In this paper, 2D eigenvalue analysis is used to study the effects of surface roughness in the context of transition delay over subsonic and supersonic swept wing configurations, as well as boundarylayer tripping on the forebody of a hypersonic air breathing vehicle.

  12. Analysis of control interval for foundation fieldbus-based control systems.

    PubMed

    Pang, Yanbin; Yang, Shuang-Hua; Nishitani, Hirokazu

    2006-07-01

    Fieldbus-based control systems (FCS) have been increasingly used in process automation. Some processes and dynamic specifications need higher control frequencies to avoid instability. The aim of this paper is to analyze the temporal characteristics of communication and computation tasks and the configuration of the function blocks in a FCS and to allow the control interval to be shortened. An FCS for a water tank process is used as a case study. The experimental results show that the execution time of function blocks and the margin time are dominant over communication delays, and optimizing configuration by reducing the number of external links can contribute to increasing the control frequency.

  13. Model-Based Analysis of Context-Specific Cognitive Control

    PubMed Central

    King, Joseph A.; Donkin, Christopher; Korb, Franziska M.; Egner, Tobias

    2012-01-01

    Interference resolution is improved for stimuli presented in contexts (e.g., locations) associated with frequent conflict. This phenomenon, the context-specific proportion congruent (CSPC) effect, has challenged the traditional juxtaposition of “automatic” and “controlled” processing because it suggests that contextual cues can prime top-down control settings in a bottom-up manner. We recently obtained support for this “priming of control” hypothesis with functional magnetic resonance imaging by showing that CSPC effects are mediated by contextually cued adjustments in processing selectivity. However, an equally plausible explanation is that CSPC effects reflect adjustments in response caution triggered by expectancy violations (i.e., prediction errors) when encountering rare events as compared to common ones (e.g., incongruent trials in a task context associated with infrequent conflict). Here, we applied a quantitative model of choice, the linear ballistic accumulator (LBA), to distil the reaction time and accuracy data from four independent samples that performed a modified flanker task into latent variables representing the psychological processes underlying task-related decision making. We contrasted models which differentially accounted for CSPC effects as arising either from contextually cued shifts in the rate of sensory evidence accumulation (“drift” models) or in the amount of evidence required to reach a decision (“threshold” models). For the majority of the participants, the LBA ascribed CSPC effects to increases in response threshold for contextually infrequent trial types (e.g., congruent trials in the frequent conflict context), suggesting that the phenomenon may reflect more a prediction error-triggered shift in decision criterion rather than enhanced sensory evidence accumulation under conditions of frequent conflict. PMID:23015795

  14. 75 FR 8239 - School Food Safety Program Based on Hazard Analysis and Critical Control Point Principles (HACCP...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ... Critical Control Point Principles (HACCP); Approval of Information Collection Request AGENCY: Food and... rule entitled School Food Safety Program Based on Hazard Analysis and Critical Control Point...

  15. Analysis of Interval Control System Robust Quality Indices on the Base of Root and Coefficient Methods

    NASA Astrophysics Data System (ADS)

    Gayvoronskiy, S. A.; Ezangina, T.; Khozhaev, I.

    2017-09-01

    Considered paper is dedicated to interval control system quality analysis with the help of root locus method and method of coefficient estimates. On the base of the first method, an algorithm of determining examinable vertices of interval characteristic polynomial coefficients polytope, which images determine robust root quality indices. On the base of coefficients method, sufficient conditions, linking coefficients of interval characteristic polynomial coefficients with quantitative estimates of robust root quality indices. With the help of both developed approaches, a robust control quality of unmanned underwater vehicle control systems was analyzed.

  16. Pseudo-inverse Jacobian control with grey relational analysis for robot manipulators mounted on oscillatory bases

    NASA Astrophysics Data System (ADS)

    Lin, J.; Lin, C. C.; Lo, H.-S.

    2009-10-01

    Interest in complex robotic systems is growing in new application areas. An example of such a robotic system is a dexterous manipulator mounted on an oscillatory base. In literature, such systems are known as macro/micro systems. This work proposes pseudo-inverse Jacobian feedback control laws and applies grey relational analysis for tuning outer-loop PID control parameters of Cartesian computed-torque control law for robotic manipulators mounted on oscillatory bases. The priority when modifying controller parameters should be the top ranking importance among parameters. Grey relational grade is utilized to investigate the sensitivity of tuning the auxiliary signal PID of the Cartesian computed-torque law to achieve desired performance. Results of this study can be feasible to numerous mechanical systems, such as mobile robots, gantry cranes, underwater robots, and other dynamic systems mounted on oscillatory bases, for moving the end-effector to a desired Cartesian position.

  17. Neural Network Based Modeling and Analysis of LP Control Surface Allocation

    NASA Technical Reports Server (NTRS)

    Langari, Reza; Krishnakumar, Kalmanje; Gundy-Burlet, Karen

    2003-01-01

    This paper presents an approach to interpretive modeling of LP based control allocation in intelligent flight control. The emphasis is placed on a nonlinear interpretation of the LP allocation process as a static map to support analytical study of the resulting closed loop system, albeit in approximate form. The approach makes use of a bi-layer neural network to capture the essential functioning of the LP allocation process. It is further shown via Lyapunov based analysis that under certain relatively mild conditions the resulting closed loop system is stable. Some preliminary conclusions from a study at Ames are stated and directions for further research are given at the conclusion of the paper.

  18. Stabilisation analysis for switched neutral systems based on sampled-data control

    NASA Astrophysics Data System (ADS)

    Krishnasamy, R.; Balasubramaniam, P.

    2015-10-01

    In this paper, the problem of stabilisation analysis for switched neutral systems based on sampled-data control and average dwell time approach is investigated. Delay-dependent stabilisation results are derived in terms of linear matrix inequalities by constructing piecewise Lyapunov-Krasovskii functional based on the Wirtinger's inequality. Also, the controller gain matrix is designed by applying an input-delay approach. Further convex combination technique and some integral inequalities are used to derive less conservative results. The effectiveness of the derived results is validated through numerical examples.

  19. Semi-active vibration control based on unsymmetrical synchronized switch damping: Analysis and experimental validation of control performance

    NASA Astrophysics Data System (ADS)

    Ji, Hongli; Qiu, Jinhao; Cheng, Li; Nie, Hong

    2016-05-01

    In semi-active synchronized switch damping (SSD) approaches for structural vibration control, the damping effect is achieved by properly switching the voltage on the piezoelectric actuators. Unsymmetrical SSD switch circuit has been designed in the previous paper to increase the effective voltage range on the PZT actuator for improvement of the control performance. In this study, analysis and experimental validation of control performance of a synchronized switch damping system based on the unsymmetrical switch circuit are carried out. First the model of an unsymmetrical SSD system is presented and the working principle is introduced. The general expression of the switched voltage on the piezoelectric actuator is derived. Based on its periodicity in steady-state control, the harmonic components of the actuator voltage are derived using Fourier series expansion. Next, the displacement response of the system is derived under combined actions of the excitation and switched voltage. Finally, a setup of a flexible beam with unsymmetrical switch circuit is used to demonstrate the control performance under different voltage sources and to verify the theoretical results. The results show that the control performance mainly depends on the voltage range on the PZT. A higher effective voltage range can be generated in unsymmetrical SSDV than in symmetrical SSDV and better control performance can be achieved at the same negative actuator voltage. The unsymmetrical SSDV makes better utilization of the actuator capability.

  20. Coordinate based meta-analysis of functional neuroimaging data; false discovery control and diagnostics.

    PubMed

    Tench, Christopher R; Tanasescu, Radu; Auer, Dorothee P; Constantinescu, Cris S

    2013-01-01

    Coordinate based meta-analysis (CBMA) is widely used to find regions of consistent activation across fMRI studies that have been selected for their functional relevance to a given hypothesis. Only reported coordinates (foci), and a model of their spatial uncertainty, are used in the analysis. Results are clusters of foci where multiple studies have reported in the same spatial region, indicating functional relevance. There are several published methods that perform the analysis in a voxel-wise manner, resulting in around 10(5) statistical tests, and considerable emphasis placed on controlling the risk of type 1 statistical error. Here we address this issue by dramatically reducing the number of tests, and by introducing a new false discovery rate control: the false cluster discovery rate (FCDR). FCDR is particularly interpretable and relevant to the results of CBMA, controlling the type 1 error by limiting the proportion of clusters that are expected under the null hypothesis. We also introduce a data diagnostic scheme to help ensure quality of the analysis, and demonstrate its use in the example studies. We show that we control the false clusters better than the widely used ALE method by performing numerical experiments, and that our clustering scheme results in more complete reporting of structures relevant to the functional task.

  1. Internet-based interventions for posttraumatic stress: A meta-analysis of randomized controlled trials.

    PubMed

    Kuester, Annika; Niemeyer, Helen; Knaevelsrud, Christine

    2016-02-01

    Posttraumatic stress disorder (PTSD) is a prevalent and highly distressing affliction, but access to trauma-focused psychotherapy is limited. Internet-based interventions (IBIs) could improve the delivery of and access to specialized mental health care. Currently, no meta-analytical evidence is available on IBIs for PTSD. We conducted a meta-analysis of 20 randomized controlled studies, including 21 comparisons, in order to summarize the current state of efficacy for the treatment of PTSD and to identify moderator variables. Studies tested internet-based cognitive behavioral therapy (CBT) and expressive writing (EW) against active or passive comparison conditions, including subclinical and clinical samples. Results show that at post-assessment CBT-IBIs are significantly more efficacious than passive controls, resulting in medium to large effects on the PTSD sum and all sub-symptom scores (0.66controls. EW differed from controls only at follow-up in reducing intrusions and hyperarousal, but based on merely two studies. Subgroup analyses reveal that for CBT none of the program components such as provision of therapeutic support, reminders, or number of sessions serves as a moderator. Overall, results for CBT-IBIs are promising, but the number of includable studies for subgroup analyses was low, limiting statistical power. Future research is necessary to systematically investigate the impact of treatment components and test against active controls with optimal power.

  2. Principal components analysis based control of a multi-dof underactuated prosthetic hand

    PubMed Central

    2010-01-01

    Background Functionality, controllability and cosmetics are the key issues to be addressed in order to accomplish a successful functional substitution of the human hand by means of a prosthesis. Not only the prosthesis should duplicate the human hand in shape, functionality, sensorization, perception and sense of body-belonging, but it should also be controlled as the natural one, in the most intuitive and undemanding way. At present, prosthetic hands are controlled by means of non-invasive interfaces based on electromyography (EMG). Driving a multi degrees of freedom (DoF) hand for achieving hand dexterity implies to selectively modulate many different EMG signals in order to make each joint move independently, and this could require significant cognitive effort to the user. Methods A Principal Components Analysis (PCA) based algorithm is used to drive a 16 DoFs underactuated prosthetic hand prototype (called CyberHand) with a two dimensional control input, in order to perform the three prehensile forms mostly used in Activities of Daily Living (ADLs). Such Principal Components set has been derived directly from the artificial hand by collecting its sensory data while performing 50 different grasps, and subsequently used for control. Results Trials have shown that two independent input signals can be successfully used to control the posture of a real robotic hand and that correct grasps (in terms of involved fingers, stability and posture) may be achieved. Conclusions This work demonstrates the effectiveness of a bio-inspired system successfully conjugating the advantages of an underactuated, anthropomorphic hand with a PCA-based control strategy, and opens up promising possibilities for the development of an intuitively controllable hand prosthesis. PMID:20416036

  3. Principal components analysis based control of a multi-DoF underactuated prosthetic hand.

    PubMed

    Matrone, Giulia C; Cipriani, Christian; Secco, Emanuele L; Magenes, Giovanni; Carrozza, Maria Chiara

    2010-04-23

    Functionality, controllability and cosmetics are the key issues to be addressed in order to accomplish a successful functional substitution of the human hand by means of a prosthesis. Not only the prosthesis should duplicate the human hand in shape, functionality, sensorization, perception and sense of body-belonging, but it should also be controlled as the natural one, in the most intuitive and undemanding way. At present, prosthetic hands are controlled by means of non-invasive interfaces based on electromyography (EMG). Driving a multi degrees of freedom (DoF) hand for achieving hand dexterity implies to selectively modulate many different EMG signals in order to make each joint move independently, and this could require significant cognitive effort to the user. A Principal Components Analysis (PCA) based algorithm is used to drive a 16 DoFs underactuated prosthetic hand prototype (called CyberHand) with a two dimensional control input, in order to perform the three prehensile forms mostly used in Activities of Daily Living (ADLs). Such Principal Components set has been derived directly from the artificial hand by collecting its sensory data while performing 50 different grasps, and subsequently used for control. Trials have shown that two independent input signals can be successfully used to control the posture of a real robotic hand and that correct grasps (in terms of involved fingers, stability and posture) may be achieved. This work demonstrates the effectiveness of a bio-inspired system successfully conjugating the advantages of an underactuated, anthropomorphic hand with a PCA-based control strategy, and opens up promising possibilities for the development of an intuitively controllable hand prosthesis.

  4. Computational Design and Analysis of a Microtab Based Aerodynamic Loads Control System for Lifting Surfaces

    NASA Astrophysics Data System (ADS)

    van Dam, Cornelis P.; Nakafuji, Dora Y.; Bauer, Candice; Standish, Kevin; Chao, David

    2003-01-01

    A computational design and analysis of a microtab based aerodynamic loads control system is presented. The microtab consists of a small tab that emerges from a wing approximately perpendicular to its surface in the vicinity of its trailing edge. Tab deployment on the upper side of the wing causes a decrease in the lift generation whereas deployment on the pressure side causes an increase. The computational methods applied in the development of this concept solve the governing Reynolds-averaged Navier-Stokes equations on structured, overset grids. The application of these methods to simulate the flows over lifting surfaces including the tabs has been paramount in the development of these devices. The numerical results demonstrate the effectiveness of the microtab and that it is possible to carry out a sensitivity analysis on the positioning and sizing of the tabs before they are implemented in successfully controlling the aerodynamic loads.

  5. Simulation and stability analysis of neural network based control scheme for switched linear systems.

    PubMed

    Singh, H P; Sukavanam, N

    2012-01-01

    This paper proposes a new adaptive neural network based control scheme for switched linear systems with parametric uncertainty and external disturbance. A key feature of this scheme is that the prior information of the possible upper bound of the uncertainty is not required. A feedforward neural network is employed to learn this upper bound. The adaptive learning algorithm is derived from Lyapunov stability analysis so that the system response under arbitrary switching laws is guaranteed uniformly ultimately bounded. A comparative simulation study with robust controller given in [Zhang L, Lu Y, Chen Y, Mastorakis NE. Robust uniformly ultimate boundedness control for uncertain switched linear systems. Computers and Mathematics with Applications 2008; 56: 1709-14] is presented. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Transient stability and control of renewable generators based on Hamiltonian surface shaping and power flow control. Part II, analysis.

    SciTech Connect

    Robinett, Rush D., III; Wilson, David Gerald

    2010-11-01

    The swing equations for renewable generators connected to the grid are developed and a wind turbine is used as an example. The swing equations for the renewable generators are formulated as a natural Hamiltonian system with externally applied non-conservative forces. A two-step process referred to as Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is used to analyze and design feedback controllers for the renewable generators system. This formulation extends previous results on the analytical verification of the Potential Energy Boundary Surface (PEBS) method to nonlinear control analysis and design and justifies the decomposition of the system into conservative and non-conservative systems to enable a two-step, serial analysis and design procedure. The first step is to analyze the system as a conservative natural Hamiltonian system with no externally applied non-conservative forces. The Hamiltonian surface of the swing equations is related to the Equal-Area Criterion and the PEBS method to formulate the nonlinear transient stability problem. This formulation demonstrates the effectiveness of proportional feedback control to expand the stability region. The second step is to analyze the system as natural Hamiltonian system with externally applied non-conservative forces. The time derivative of the Hamiltonian produces the work/rate (power flow) equation which is used to ensure balanced power flows from the renewable generators to the loads. The Second Law of Thermodynamics is applied to the power flow equations to determine the stability boundaries (limit cycles) of the renewable generators system and enable design of feedback controllers that meet stability requirements while maximizing the power generation and flow to the load. Necessary and sufficient conditions for stability of renewable generators systems are determined based on the concepts of Hamiltonian systems, power flow, exergy (the maximum work that can be extracted from an energy flow) rate

  7. Digital Instrumentation and Control Failure Events Derivation and Analysis by Frame-Based Technique

    SciTech Connect

    Hui-Wen Huang; Chunkuan Shih; Swu Yih; Yen-Chang Tzeng; Ming-Huei Chen

    2006-07-01

    A frame-based technique, including physical frame, logical frame, and cognitive frame, was adopted to perform digital I and C failure events derivation and analysis for generic ABWR. The physical frame was structured with a modified PCTran-ABWR plant simulation code, which was extended and enhanced on the feedwater system, recirculation system, and steam line system. The logical model is structured with MATLAB, which was incorporated into PCTran-ABWR to improve the pressure control system, feedwater control system, recirculation control system, and automated power regulation control system. As a result, the software failure of these digital control systems can be properly simulated and analyzed. The cognitive frame was simulated by the operator awareness status in the scenarios. Moreover, via an internal characteristics tuning technique, the modified PCTran-ABWR can precisely reflect the characteristics of the power-core flow. Hence, in addition to the transient plots, the analysis results can then be demonstrated on the power-core flow map. A number of postulated I and C system software failure events were derived to achieve the dynamic analyses. The basis for event derivation includes the published classification for software anomalies, the digital I and C design data for ABWR, chapter 15 accident analysis of generic SAR, and the reported NPP I and C software failure events. The case study of this research includes (1) the software CMF analysis for the major digital control systems; and (2) postulated ABWR digital I and C software failure events derivation from the actual happening of non-ABWR digital I and C software failure events, which were reported to LER of USNRC or IRS of IAEA. These events were analyzed by PCTran-ABWR. Conflicts among plant status, computer status, and human cognitive status are successfully identified. The operator might not easily recognize the abnormal condition, because the computer status seems to progress normally. However, a well

  8. Effect of Web-based lifestyle modification on weight control: a meta-analysis.

    PubMed

    Kodama, S; Saito, K; Tanaka, S; Horikawa, C; Fujiwara, K; Hirasawa, R; Yachi, Y; Iida, K T; Shimano, H; Ohashi, Y; Yamada, N; Sone, H

    2012-05-01

    Web-based treatment programs are attractive in primary care because of their ability to reach numerous individuals at low cost. Our aim of this meta-analysis is to systematically review the weight loss or maintenance effect of the Internet component in obesity treatment programs. MEDLINE and EMBASE literature searches were conducted to identify studies investigating the effect of Web-based individualized advice on lifestyle modification on weight loss. Randomized controlled trials that consisted of a Web-user experimental and non-Web user control group were included. Weight changes in the experimental group in comparison with the control group were pooled with a random-effects model. A total of 23 studies comprising 8697 participants were included. Overall, using the Internet had a modest but significant additional weight-loss effect compared with non-Web user control groups (-0.68 kg, P=0.03). In comparison with the control group, stratified analysis indicated that using the Internet as an adjunct to obesity care was effective (-1.00 kg, P<0.001), but that using it as a substitute for face-to-face support was unfavorable (+1.27 kg, P=0.01). An additional effect on weight control was observed when the aim of using the Internet was initial weight loss (-1.01 kg; P=0.03), but was not observed when the aim was weight maintenance (+0.68 kg; P=0.26). The relative effect was diminished with longer educational periods (P-trend=0.04) and was insignificant (-0.20 kg; P=0.75) in studies with educational periods of 12 months or more. The current meta-analysis indicates that the Internet component in obesity treatment programs has a modest effect on weight control. However, the effect was inconsistent, largely depending on the type of usage of the Internet or the period of its use.

  9. Interdisciplinary analysis procedures in the modeling and control of large space-based structures

    NASA Technical Reports Server (NTRS)

    Cooper, Paul A.; Stockwell, Alan E.; Kim, Zeen C.

    1987-01-01

    The paper describes a computer software system called the Integrated Multidisciplinary Analysis Tool, IMAT, that has been developed at NASA Langley Research Center. IMAT provides researchers and analysts with an efficient capability to analyze satellite control systems influenced by structural dynamics. Using a menu-driven interactive executive program, IMAT links a relational database to commercial structural and controls analysis codes. The paper describes the procedures followed to analyze a complex satellite structure and control system. The codes used to accomplish the analysis are described, and an example is provided of an application of IMAT to the analysis of a reference space station subject to a rectangular pulse loading at its docking port.

  10. Childhood autism in India: A case-control study using tract-based spatial statistics analysis.

    PubMed

    Assis, Zarina Abdul; Bagepally, Bhavani Shankara; Saini, Jitender; Srinath, Shoba; Bharath, Rose Dawn; Naidu, Purushotham R; Gupta, Arun Kumar

    2015-01-01

    Autism is a serious behavioral disorder among young children that now occurs at epidemic rates in developing countries like India. We have used tract-based spatial statistics (TBSS) of diffusion tensor imaging (DTI) measures to investigate the microstructure of primary neurocircuitry involved in autistic spectral disorders as compared to the typically developed children. To evaluate the various white matter tracts in Indian autistic children as compared to the controls using TBSS. Prospective, case-control, voxel-based, whole-brain DTI analysis using TBSS was performed. The study included 19 autistic children (mean age 8.7 years ± 3.84, 16 males and 3 females) and 34 controls (mean age 12.38 ± 3.76, all males). Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) values were used as outcome variables. Compared to the control group, TBSS demonstrated multiple areas of markedly reduced FA involving multiple long white matter tracts, entire corpus callosum, bilateral posterior thalami, and bilateral optic tracts (OTs). Notably, there were no voxels where FA was significantly increased in the autism group. Increased RD was also noted in these regions, suggesting underlying myelination defect. The MD was elevated in many of the projections and association fibers and notably in the OTs. There were no significant changes in the AD in these regions, indicating no significant axonal injury. There was no significant correlation between the FA values and Childhood Autism Rating Scale. This is a first of a kind study evaluating DTI findings in autistic children in India. In our study, DTI has shown a significant fault with the underlying intricate brain wiring system in autism. OT abnormality is a novel finding and needs further research.

  11. Childhood autism in India: A case-control study using tract-based spatial statistics analysis

    PubMed Central

    Assis, Zarina Abdul; Bagepally, Bhavani Shankara; Saini, Jitender; Srinath, Shoba; Bharath, Rose Dawn; Naidu, Purushotham R.; Gupta, Arun Kumar

    2015-01-01

    Context: Autism is a serious behavioral disorder among young children that now occurs at epidemic rates in developing countries like India. We have used tract-based spatial statistics (TBSS) of diffusion tensor imaging (DTI) measures to investigate the microstructure of primary neurocircuitry involved in autistic spectral disorders as compared to the typically developed children. Objective: To evaluate the various white matter tracts in Indian autistic children as compared to the controls using TBSS. Materials and Methods: Prospective, case-control, voxel-based, whole-brain DTI analysis using TBSS was performed. The study included 19 autistic children (mean age 8.7 years ± 3.84, 16 males and 3 females) and 34 controls (mean age 12.38 ± 3.76, all males). Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) values were used as outcome variables. Results: Compared to the control group, TBSS demonstrated multiple areas of markedly reduced FA involving multiple long white matter tracts, entire corpus callosum, bilateral posterior thalami, and bilateral optic tracts (OTs). Notably, there were no voxels where FA was significantly increased in the autism group. Increased RD was also noted in these regions, suggesting underlying myelination defect. The MD was elevated in many of the projections and association fibers and notably in the OTs. There were no significant changes in the AD in these regions, indicating no significant axonal injury. There was no significant correlation between the FA values and Childhood Autism Rating Scale. Conclusion: This is a first of a kind study evaluating DTI findings in autistic children in India. In our study, DTI has shown a significant fault with the underlying intricate brain wiring system in autism. OT abnormality is a novel finding and needs further research. PMID:26600581

  12. Impact of the Massachusetts tobacco control programme: population based trend analysis

    PubMed Central

    Biener, Lois; Harris, Jeffrey E; Hamilton, William

    2000-01-01

    Objective To assess the impact of the Massachusetts tobacco control programme, which, since its start in January 1993, has spent over $200m—“the highest per capita expenditure for tobacco control in the world”—funded by an extra tax of 25 cents per pack of cigarettes. Design Population based trend analysis with comparison group. Subjects Adult residents of Massachusetts and other US states excluding California. Main outcome measures Per capita consumption of cigarettes as measured by states' sales tax records; prevalence of smoking in adults as measured by several population-based telephone surveys. Results From 1988 to 1992, decline in per capita consumption of cigarettes in Massachusetts (15%) was similar to that in the comparison states (14%), corresponding to an annual decline of 3-4% for both groups. During 1992-3, consumption continued to decline by 4% in the comparison states but dropped 12% in Massachusetts in response to the tax increase. From 1993 onward, consumption in Massachusetts showed a consistent annual decline of more than 4%, whereas in the comparison states it levelled off, decreasing by less than 1% a year. From 1992, the prevalence of adult smoking in Massachusetts has declined annually by 0.43% (95% confidence interval 0.21% to 0.66%) compared with an increase of 0.03% (-0.06% to 0.12%) in the comparison states (P<0.001). Conclusions These findings show that a strongly implemented, comprehensive tobacco control programme can significantly reduce tobacco use. PMID:10926595

  13. Motion control skill assessment based on kinematic analysis of robotic end-effector movements.

    PubMed

    Liang, Ke; Xing, Yuan; Li, Jianmin; Wang, Shuxin; Li, Aimin; Li, Jinhua

    2017-06-29

    The performance of robotic end-effector movements can reflect the user's operation skill difference in robot-assisted minimally invasive surgery. This study quantified the trade-off of speed-accuracy-stability by kinematic analysis of robotic end-effector movements to assess the motion control skill of users with different levels of experience. Using 'MicroHand S' system, 10 experts, 10 residents and 10 novices performed single-hand test and bimanual coordination test. Eight metrics based on the movements of robotic end-effectors were applied to evaluate the users' performance. In the single-hand test, experts outperformed other groups except for movement speed; in the bimanual coordination test, experts also performed better except for movement time and movement speed. No statistically significant difference in performance was found between residents and novices. The kinematic differences obtained from the movements of robotic end-effectors can be applied to assess the motion control skill of users with different skill levels. Copyright © 2017 John Wiley & Sons, Ltd.

  14. 78 FR 64425 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ... Manufacturing Practice and Hazard Analysis and Risk- Based Preventive Controls for Food for Animals; Public... proposed rule to establish requirements for current good manufacturing practice and hazard analysis and... that will establish the foundation of, and central framework for, the modern food safety system...

  15. Stability analysis and compensation of network-induced delays in communication-based power system control: A survey.

    PubMed

    Liu, Shichao; Liu, Peter Xiaoping; Wang, Xiaoyu

    2017-01-01

    This survey is to summarize and compare existing and recently emerging approaches for the analysis and compensation of the effects of network-induced delays on the stability and performance of communication-based power control systems. Several important communication-based power control systems are briefly introduced. The deterministic and stochastic methodologies of analyzing the impacts of network-induced delays on the stability of the communication-based power control systems are summarized and compared. A variety of control approaches are reviewed and compared for mitigating the effects of network-induced delays, depending on several design requirements, such as model dependence and design difficulty. The summary and comparison of these control approaches in this survey provide researchers and utilities valuable guidance for designing advanced communication-based power control systems in the future.

  16. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis.

    PubMed

    Foong, Shaohui; Sun, Zhenglong

    2016-08-12

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison.

  17. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis

    PubMed Central

    Foong, Shaohui; Sun, Zhenglong

    2016-01-01

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison. PMID:27529253

  18. Integrated quality control: implementation and validation of instrument function checks and procedural controls for a cartridge-based point-of-care system for critical care analysis.

    PubMed

    D'Orazio, Paul; Mansouri, Sohrab

    2013-03-01

    In this article, the process used to develop and validate an integrated quality-control system for a cartridge-based, point-of-care system for critical care analysis is outlined. Application of risk management principles has resulted in a quality control system using a combination of statistical quality control with onboard reference solutions and failure pattern recognition used to flag common failure modes during the analytical phase of the testing process. A combination of traditional external quality control, integrated quality control to monitor ongoing instrument functionality, operator training, and other laboratory-implemented monitors is most effective in controlling known failure modes during the testing process.

  19. Analysis and Synthesis of Memory-Based Fuzzy Sliding Mode Controllers.

    PubMed

    Zhang, Jinhui; Lin, Yujuan; Feng, Gang

    2015-12-01

    This paper addresses the sliding mode control problem for a class of Takagi-Sugeno fuzzy systems with matched uncertainties. Different from the conventional memoryless sliding surface, a memory-based sliding surface is proposed which consists of not only the current state but also the delayed state. Both robust and adaptive fuzzy sliding mode controllers are designed based on the proposed memory-based sliding surface. It is shown that the sliding surface can be reached and the closed-loop control system is asymptotically stable. Furthermore, to reduce the chattering, some continuous sliding mode controllers are also presented. Finally, the ball and beam system is used to illustrate the advantages and effectiveness of the proposed approaches. It can be seen that, with the proposed control approaches, not only can the stability be guaranteed, but also its transient performance can be improved significantly.

  20. Control-based continuation: Bifurcation and stability analysis for physical experiments

    NASA Astrophysics Data System (ADS)

    Barton, David A. W.

    2017-02-01

    Control-based continuation is technique for tracking the solutions and bifurcations of nonlinear experiments. The idea is to apply the method of numerical continuation to a feedback-controlled physical experiment such that the control becomes non-invasive. Since in an experiment it is not (generally) possible to set the state of the system directly, the control target becomes a proxy for the state. Control-based continuation enables the systematic investigation of the bifurcation structure of a physical system, much like if it was numerical model. However, stability information (and hence bifurcation detection and classification) is not readily available due to the presence of stabilising feedback control. This paper uses a periodic auto-regressive model with exogenous inputs (ARX) to approximate the time-varying linearisation of the experiment around a particular periodic orbit, thus providing the missing stability information. This method is demonstrated using a physical nonlinear tuned mass damper.

  1. Analysis of Documentation Speed Using Web-Based Medical Speech Recognition Technology: Randomized Controlled Trial

    PubMed Central

    Kaisers, Wolfgang; Wassmuth, Ralf; Mayatepek, Ertan

    2015-01-01

    Background Clinical documentation has undergone a change due to the usage of electronic health records. The core element is to capture clinical findings and document therapy electronically. Health care personnel spend a significant portion of their time on the computer. Alternatives to self-typing, such as speech recognition, are currently believed to increase documentation efficiency and quality, as well as satisfaction of health professionals while accomplishing clinical documentation, but few studies in this area have been published to date. Objective This study describes the effects of using a Web-based medical speech recognition system for clinical documentation in a university hospital on (1) documentation speed, (2) document length, and (3) physician satisfaction. Methods Reports of 28 physicians were randomized to be created with (intervention) or without (control) the assistance of a Web-based system of medical automatic speech recognition (ASR) in the German language. The documentation was entered into a browser’s text area and the time to complete the documentation including all necessary corrections, correction effort, number of characters, and mood of participant were stored in a database. The underlying time comprised text entering, text correction, and finalization of the documentation event. Participants self-assessed their moods on a scale of 1-3 (1=good, 2=moderate, 3=bad). Statistical analysis was done using permutation tests. Results The number of clinical reports eligible for further analysis stood at 1455. Out of 1455 reports, 718 (49.35%) were assisted by ASR and 737 (50.65%) were not assisted by ASR. Average documentation speed without ASR was 173 (SD 101) characters per minute, while it was 217 (SD 120) characters per minute using ASR. The overall increase in documentation speed through Web-based ASR assistance was 26% (P=.04). Participants documented an average of 356 (SD 388) characters per report when not assisted by ASR and 649 (SD

  2. Analysis of Documentation Speed Using Web-Based Medical Speech Recognition Technology: Randomized Controlled Trial.

    PubMed

    Vogel, Markus; Kaisers, Wolfgang; Wassmuth, Ralf; Mayatepek, Ertan

    2015-11-03

    Clinical documentation has undergone a change due to the usage of electronic health records. The core element is to capture clinical findings and document therapy electronically. Health care personnel spend a significant portion of their time on the computer. Alternatives to self-typing, such as speech recognition, are currently believed to increase documentation efficiency and quality, as well as satisfaction of health professionals while accomplishing clinical documentation, but few studies in this area have been published to date. This study describes the effects of using a Web-based medical speech recognition system for clinical documentation in a university hospital on (1) documentation speed, (2) document length, and (3) physician satisfaction. Reports of 28 physicians were randomized to be created with (intervention) or without (control) the assistance of a Web-based system of medical automatic speech recognition (ASR) in the German language. The documentation was entered into a browser's text area and the time to complete the documentation including all necessary corrections, correction effort, number of characters, and mood of participant were stored in a database. The underlying time comprised text entering, text correction, and finalization of the documentation event. Participants self-assessed their moods on a scale of 1-3 (1=good, 2=moderate, 3=bad). Statistical analysis was done using permutation tests. The number of clinical reports eligible for further analysis stood at 1455. Out of 1455 reports, 718 (49.35%) were assisted by ASR and 737 (50.65%) were not assisted by ASR. Average documentation speed without ASR was 173 (SD 101) characters per minute, while it was 217 (SD 120) characters per minute using ASR. The overall increase in documentation speed through Web-based ASR assistance was 26% (P=.04). Participants documented an average of 356 (SD 388) characters per report when not assisted by ASR and 649 (SD 561) characters per report when assisted

  3. A probabilistic framework for the exploration of enzymatic capabilities based on feasible kinetics and control analysis.

    PubMed

    Saa, Pedro A; Nielsen, Lars K

    2016-03-01

    Analysis of limiting steps within enzyme-catalyzed reactions is fundamental to understand their behavior and regulation. Methods capable of unravelling control properties and exploring kinetic capabilities of enzymatic reactions would be particularly useful for protein and metabolic engineering. While single-enzyme control analysis formalism has previously been applied to well-studied enzymatic mechanisms, broader application of this formalism is limited in practice by the limited amount of kinetic data and the difficulty of describing complex allosteric mechanisms. To overcome these limitations, we present here a probabilistic framework enabling control analysis of previously unexplored mechanisms under uncertainty. By combining a thermodynamically consistent parameterization with an efficient Sequential Monte Carlo sampler embedded in a Bayesian setting, this framework yields insights into the capabilities of enzyme-catalyzed reactions with modest kinetic information, provided that the catalytic mechanism and a thermodynamic reference point are defined. The framework was used to unravel the impact of thermodynamic affinity, substrate saturation levels and effector concentrations on the flux control and response coefficients of a diverse set of enzymatic reactions. Our results highlight the importance of the metabolic context in the control analysis of isolated enzymes as well as the use of statistically sound methods for their interpretation. This framework significantly expands our current capabilities for unravelling the control properties of general reaction kinetics with limited amount of information. This framework will be useful for both theoreticians and experimentalists in the field. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  4. Prison tobacco control policies and deaths from smoking in United States prisons: population based retrospective analysis

    PubMed Central

    Carson, E Ann; Krueger, Patrick M; Mueller, Shane R; Steiner, John F; Sabol, William J

    2014-01-01

    Objective To determine the mortality attributable to smoking and years of potential life lost from smoking among people in prison and whether bans on smoking in prison are associated with reductions in smoking related deaths. Design Analysis of cross sectional survey data with the smoking attributable mortality, morbidity, and economic costs system; population based time series analysis. Setting All state prisons in the United States. Main outcome measures Prevalence of smoking from cross sectional survey of inmates in state correctional facilities. Data on state prison tobacco policies from web based searches of state policies and legislation. Deaths and causes of death in US state prisons from the deaths in custody reporting program of the Bureau of Justice Statistics for 2001-11. Smoking attributable mortality and years of potential life lost was assessed from the smoking attributable mortality, morbidity, and economic costs system of the Centers for Disease Control and Prevention. Multivariate Poisson models quantified the association between bans and smoking related cancer, cardiovascular and pulmonary deaths. Results The most common causes of deaths related to smoking among people in prison were lung cancer, ischemic heart disease, other heart disease, cerebrovascular disease, and chronic airways obstruction. The age adjusted smoking attributable mortality and years of potential life lost rates were 360 and 5149 per 100 000, respectively; these figures are higher than rates in the general US population (248 and 3501, respectively). The number of states with any smoking ban increased from 25 in 2001 to 48 by 2011. In prisons the mortality rate from smoking related causes was lower during years with a ban than during years without a ban (110.4/100 000 v 128.9/100 000). Prisons that implemented smoking bans had a 9% reduction (adjusted incidence rate ratio 0.91, 95% confidence interval 0.88 to 0.95) in smoking related deaths. Bans in place for longer than

  5. Prison tobacco control policies and deaths from smoking in United States prisons: population based retrospective analysis.

    PubMed

    Binswanger, Ingrid A; Carson, E Ann; Krueger, Patrick M; Mueller, Shane R; Steiner, John F; Sabol, William J

    2014-08-05

    To determine the mortality attributable to smoking and years of potential life lost from smoking among people in prison and whether bans on smoking in prison are associated with reductions in smoking related deaths. Analysis of cross sectional survey data with the smoking attributable mortality, morbidity, and economic costs system; population based time series analysis. All state prisons in the United States. Prevalence of smoking from cross sectional survey of inmates in state correctional facilities. Data on state prison tobacco policies from web based searches of state policies and legislation. Deaths and causes of death in US state prisons from the deaths in custody reporting program of the Bureau of Justice Statistics for 2001-11. Smoking attributable mortality and years of potential life lost was assessed from the smoking attributable mortality, morbidity, and economic costs system of the Centers for Disease Control and Prevention. Multivariate Poisson models quantified the association between bans and smoking related cancer, cardiovascular and pulmonary deaths. The most common causes of deaths related to smoking among people in prison were lung cancer, ischemic heart disease, other heart disease, cerebrovascular disease, and chronic airways obstruction. The age adjusted smoking attributable mortality and years of potential life lost rates were 360 and 5149 per 100,000, respectively; these figures are higher than rates in the general US population (248 and 3501, respectively). The number of states with any smoking ban increased from 25 in 2001 to 48 by 2011. In prisons the mortality rate from smoking related causes was lower during years with a ban than during years without a ban (110.4/100,000 v 128.9/100,000). Prisons that implemented smoking bans had a 9% reduction (adjusted incidence rate ratio 0.91, 95% confidence interval 0.88 to 0.95) in smoking related deaths. Bans in place for longer than nine years were associated with reductions in cancer

  6. Analysis and implementation of a structural vibration control algorithm based on an IIR adaptive filter

    NASA Astrophysics Data System (ADS)

    Huang, Quanzhen; Luo, Jun; Li, Hengyu; Wang, Xiaohua

    2013-08-01

    With the wide application of large-scale flexible structures in spacecraft, vibration control problems in these structures have become important design issues. The filtered-X least mean square (FXLMS) algorithm is the most popular one in current active vibration control using adaptive filtering. It assumes that the source of interference can be measured and the interference source is considered as the reference signal input to the controller. However, in the actual control system, this assumption is not accurate, because it does not consider the impact of the reference signal on the output feedback signal. In this paper, an adaptive vibration active control algorithm based on an infinite impulse response (IIR) filter structure (FULMS, filtered-U least mean square) is proposed. The algorithm is based on an FXLMS algorithm framework, which replaces the finite impulse response (FIR) filter with an IIR filter. This paper focuses on the structural design of the controller, the process of the FULMS filtering control method, the design of the experimental model object, and the experimental platform construction for the entire control system. The comparison of the FXLMS algorithm with FULMS is theoretically analyzed and experimentally validated. The results show that the FULMS algorithm converges faster and controls better. The design of the FULMS controller is feasible and effective and has greater value in practical applications of aerospace engineering.

  7. Towards Zero Retraining for Myoelectric Control Based on Common Model Component Analysis.

    PubMed

    Liu, Jianwei; Sheng, Xinjun; Zhang, Dingguo; Jiang, Ning; Zhu, Xiangyang

    2016-04-01

    In spite of several decades of intense research and development, the existing algorithms of myoelectric pattern recognition (MPR) are yet to satisfy the criteria that a practical upper extremity prostheses should fulfill. This study focuses on the criterion of the short, or even zero subject training. Due to the inherent nonstationarity in surface electromyography (sEMG) signals, current myoelectric control algorithms usually need to be retrained daily during a multiple days' usage. This study was conducted based on the hypothesis that there exist some invariant characteristics in the sEMG signals when a subject performs the same motion in different days. Therefore, given a set of classifiers (models) trained on several days, it is possible to find common characteristics among them. To this end, we proposed to use common model component analysis (CMCA) framework, in which an optimized projection was found to minimize the dissimilarity among multiple models of linear discriminant analysis (LDA) trained using data from different days. Five intact-limbed subjects and two transradial amputee subjects participated in an experiment including six sessions of sEMG data recording, which were performed in six different days, to simulate the application of MPR over multiple days. The results demonstrate that CMCA has a significant better generalization ability with unseen data (not included in the training data), leading to classification accuracy improvement and increase of completion rate in a motion test simulation, when comparing with the baseline reference method. The results indicate that CMCA holds a great potential in the effort of developing zero retraining of MPR.

  8. Kinematics and force analysis of a robot hand based on an artificial biological control scheme

    NASA Astrophysics Data System (ADS)

    Kim, Man Guen

    An artificial biological control scheme (ABCS) is used to study the kinematics and statics of a multifingered hand with a view to developing an efficient control scheme for grasping. The ABCS is based on observation of human grasping, intuitively taking it as the optimum model for robotic grasping. A final chapter proposes several grasping measures to be applied to the design and control of a robot hand. The ABCS leads to the definition of two modes of the grasping action: natural grasping (NG), which is the human motion to grasp the object without any special task command, and forced grasping (FG), which is the motion with a specific task. The grasping direction line (GDL) is defined to determine the position and orientation of the object in the hand. The kinematic model of a redundant robot arm and hand is developed by reconstructing the human upper extremity and using anthropometric measurement data. The inverse kinematic analyses of various types of precision and power grasping are studied by replacing the three-link with one virtual link and using the GDL. The static force analysis for grasping with fingertips is studied by applying the ABCS. A measure of grasping stability, that maintains the positions of contacts as well as the configurations of the redundant fingers, is derived. The grasping stability measure (GSM), a measure of how well the hand maintains grasping under the existence of external disturbance, is derived by the torque vector of the hand calculated from the external force applied to the object. The grasping manipulability measure (GMM), a measure of how well the hand manipulates the object for the task, is derived by the joint velocity vector of the hand calculated from the object velocity. The grasping performance measure (GPM) is defined by the sum of the directional components of the GSM and the GMM. Finally, a planar redundant hand with two fingers is examined in order to study the various postures of the hand performing pinch grasping by

  9. Association between Herpesviruses and Chronic Periodontitis: A Meta-Analysis Based on Case-Control Studies

    PubMed Central

    Wong, May. Chun. Mei; Feng, Xi-Ping; Lu, Hai-Xia; Xu, Wei

    2015-01-01

    Objective Numerous studies have investigated the associations between herpesviruses and chronic periodontitis; however, the results remain controversial. To derive a more precise estimation, a meta-analysis on all available studies was performed to identify the association between herpesviruses and chronic periodontitis. Methods A computerized literature search was conducted in December 2014 to identify eligible case-control studies from the PUBMED and EMBASE databases according to inclusion and exclusion criteria. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were used to assess the association between herpesviruses and risk of chronic periodontitis. A fixed or random effects model was determined based on a heterogeneity test. Sensitivity analysis was conducted to investigate stability and reliability. Publication bias was investigated using the Begg rank correlation test and Egger's funnel plot. Results Ten eligible studies were included to investigate the association between Epstein–Barr virus (EBV) and chronic periodontitis. The results showed that EBV has a significant association with chronic periodontitis compared with periodontally healthy group (OR = 5.74, 95% CI = 2.53–13.00, P<0.001). The association between human cytomegalovirus (HCMV) and chronic periodontitis was analyzed in 10 studies. The pooled result showed that HCMV also has a significant association with chronic periodontitis (OR = 3.59, 95% CI = 1.41–9.16, P = 0.007). Similar results were found in the sensitivity analyses. No significant publication bias was observed. Two eligible studies were included to investigate the association between herpes simplex virus (HSV) and chronic periodontitis risk. The association between HSV and chronic periodontitis was inconclusive (OR = 2.81 95% CI = 0.95–8.27, P = 0.06). Only one included study investigated the association between human herpesvirus 7 (HHV-7) and chronic periodontitis risk (OR = 1.00, 95% CI = 0

  10. Delay Analysis of Networked Control Systems Based on 100 M Switched Ethernet

    PubMed Central

    2014-01-01

    For the delay may degrade the performance of networked control systems, networked control systems based on 100 M switched Ethernet are proposed in this paper. According to the working principle of Ethernet switch, the formulas of the upper bound delay of the single-level switched Ethernet and the multiple-level switched Ethernet are deduced by the timing diagram method, and the values of the upper bound delay are also given. The key factors that influence the upper bound delay of switched Ethernet are analyzed; then, the characteristics of the upper bound delay are presented, which show that the delay induced by the single-level 100 M switched Ethernet has little effect on the performance of control systems, while the delay induced by the multiple-level 100 M switched Ethernet may meet the time requirements of all classes of control systems if the numbers of levels and the numbers of nodes connecting to switches are set properly. Finally, the performance of networked control systems is simulated by TrueTime, and the results further show the feasibility and superiority of 100 M switched Ethernet based networked control systems without modification of the network protocols. PMID:25003152

  11. Robust Maneuvering Envelope Estimation Based on Reachability Analysis in an Optimal Control Formulation

    NASA Technical Reports Server (NTRS)

    Lombaerts, Thomas; Schuet, Stefan R.; Wheeler, Kevin; Acosta, Diana; Kaneshige, John

    2013-01-01

    This paper discusses an algorithm for estimating the safe maneuvering envelope of damaged aircraft. The algorithm performs a robust reachability analysis through an optimal control formulation while making use of time scale separation and taking into account uncertainties in the aerodynamic derivatives. Starting with an optimal control formulation, the optimization problem can be rewritten as a Hamilton- Jacobi-Bellman equation. This equation can be solved by level set methods. This approach has been applied on an aircraft example involving structural airframe damage. Monte Carlo validation tests have confirmed that this approach is successful in estimating the safe maneuvering envelope for damaged aircraft.

  12. a Libration Model for Enceladus Based on Geodetic Control Point Network Analysis

    NASA Astrophysics Data System (ADS)

    Nadezhdina, I. E.; Zubarev, A. E.; Brusnikin, E. S.; Oberst, J.

    2016-06-01

    A new global control point network was derived for Enceladus, based on Cassini and Voyager-2 image data. Cassini images were taken from 2005 to 2014, for Voyager we have only one flyby in the middle of 1981. We have derived 3D Cartesian coordinates for 1128 control points as well as improved pointing data for 12 Voyager and 193 Cassini images in the Enceladus-fixed coordinate system. The point accuracies vary from 55 m to 2900 m (average point accuracy - 221 m). From tracking of the control points we detect a librational motion described by a model which includes 3 different periods and amplitudes (Rambaux et al., 2011). We determine the amplitudes for each term. Our new control point network has a higher number of point measurements and a higher accuracy than previous data (Giese et al., 2014).

  13. 78 FR 24691 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-26

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Parts 1, 16, 106, 110, 114, 117, 120, 123, 129, 179, and 211 RIN 0910-AG36 Current Good Manufacturing Practice and Hazard Analysis and Risk- Based Preventive Controls for Human Food; Extension of Comment Periods AGENCY: Food and Drug Administration,...

  14. 78 FR 69604 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-20

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Parts 1, 16, 106, 110, 114, 117, 120, 123, 129, 179, and 211 RIN 0910-AG36 Current Good Manufacturing Practice and Hazard Analysis and Risk- Based Preventive Controls for Human Food; Extension of Comment Periods AGENCY: Food and Drug Administration,...

  15. Data-based controllability analysis of discrete-time linear time-delay systems

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Chen, Hong-Wei; Lu, Jian-Quan

    2014-11-01

    In this paper, a data-based method is used to analyse the controllability of discrete-time linear time-delay systems. By this method, one can directly construct a controllability matrix using the measured state data without identifying system parameters. Hence, one can save time in practice and avoid corresponding identification errors. Moreover, its calculation precision is higher than some other traditional approaches, which need to identify unknown parameters. Our methods are feasible to the study of characteristics of deterministic systems. A numerical example is given to show the advantage of our results.

  16. Analysis of an atom laser based on the spatial control of the scattering length

    SciTech Connect

    Carpentier, Alicia V.; Michinel, Humberto; Rodas-Verde, Maria I.; Perez-Garcia, Victor M.

    2006-07-15

    In this paper we analyze atom lasers based on the spatial modulation of the scattering length of a Bose-Einstein condensate. We demonstrate, through numerical simulations and approximate analytical methods, the controllable emission of matter-wave bursts and study the dependence of the process on the spatial shape of the scattering length along the axis of emission. We also study the role of an additional modulation of the scattering length in time.

  17. Design and Validation of a Morphing Myoelectric Hand Posture Controller Based on Principal Component Analysis of Human Grasping

    PubMed Central

    Segil, Jacob L.; Weir, Richard F. ff.

    2015-01-01

    An ideal myoelectric prosthetic hand should have the ability to continuously morph between any posture like an anatomical hand. This paper describes the design and validation of a morphing myoelectric hand controller based on principal component analysis of human grasping. The controller commands continuously morphing hand postures including functional grasps using between two and four surface electromyography (EMG) electrodes pairs. Four unique maps were developed to transform the EMG control signals in the principal component domain. A preliminary validation experiment was performed by 10 nonamputee subjects to determine the map with highest performance. The subjects used the myoelectric controller to morph a virtual hand between functional grasps in a series of randomized trials. The number of joints controlled accurately was evaluated to characterize the performance of each map. Additional metrics were studied including completion rate, time to completion, and path efficiency. The highest performing map controlled over 13 out of 15 joints accurately. PMID:23649286

  18. Design and validation of a morphing myoelectric hand posture controller based on principal component analysis of human grasping.

    PubMed

    Segil, Jacob L; Weir, Richard F ff

    2014-03-01

    An ideal myoelectric prosthetic hand should have the ability to continuously morph between any posture like an anatomical hand. This paper describes the design and validation of a morphing myoelectric hand controller based on principal component analysis of human grasping. The controller commands continuously morphing hand postures including functional grasps using between two and four surface electromyography (EMG) electrodes pairs. Four unique maps were developed to transform the EMG control signals in the principal component domain. A preliminary validation experiment was performed by 10 nonamputee subjects to determine the map with highest performance. The subjects used the myoelectric controller to morph a virtual hand between functional grasps in a series of randomized trials. The number of joints controlled accurately was evaluated to characterize the performance of each map. Additional metrics were studied including completion rate, time to completion, and path efficiency. The highest performing map controlled over 13 out of 15 joints accurately.

  19. P-value based analysis for shared controls design in genome-wide association studies.

    PubMed

    Zaykin, Dmitri V; Kozbur, Damian O

    2010-11-01

    An appealing genome-wide association study design compares one large control group against several disease samples. A pioneering study by the Wellcome Trust Case Control Consortium that employed such a design has identified multiple susceptibility regions, many of which have been independently replicated. While reusing a control sample provides effective utilization of data, it also creates correlation between association statistics across diseases. An observation of a large association statistic for one of the diseases may greatly increase chances of observing a spuriously large association for a different disease. Accounting for the correlation is also particularly important when screening for SNPs that might be involved in a set of diseases with overlapping etiology. We describe methods that correct association statistics for dependency due to shared controls, and we describe ways to obtain a measure of overall evidence and to combine association signals across multiple diseases. The methods we describe require no access to individual subject data, instead, they efficiently utilize information contained in P-values for association reported for individual diseases. P-value based combined tests for association are flexible and essentially as powerful as the approach based on aggregating the individual subject data. © 2010 Wiley-Liss, Inc.

  20. Quantitative and chemical fingerprint analysis for quality control of rhizoma Coptidischinensis based on UPLC-PAD combined with chemometrics methods.

    PubMed

    Kong, Wei-Jun; Zhao, Yan-Ling; Xiao, Xiao-He; Jin, Cheng; Li, Zu-Lun

    2009-10-01

    To control the quality of rhizoma Coptidis, a method based on ultra performance liquid chromatography with photodiode array detector (UPLC-PAD) was developed for quantitative analysis of five active alkaloids and chemical fingerprint analysis. In quantitative analysis, the five alkaloids showed good regression (R > 0.9992) within test ranges and the recovery of the method was in the range of 98.4-100.8%. The limit of detections and quantifications for five alkaloids in PAD were less than 0.07 and 0.22 microg/ml, respectively. In order to compare the UPLC fingerprints between rhizoma Coptidis from different origins, the chemometrics procedures, including similarity analysis (SA), hierarchical clustering analysis (HCA), principal component analysis (PCA) were applied to classify the rhizoma Coptidis samples according to their cultivated origins. Consistent results were obtained to show that rhizoma Coptidis samples could be successfully grouped in accordance with the province of origin. Furthermore, five marker constituents were screened out to be the main chemical marker, which could be applied to accurate discrimination and quality control for rhizoma Coptidis by quantitative analysis. This study revealed that UPLC-PAD method was simple, sensitive and reliable for quantitative and chemical fingerprint analysis, moreover, for the quality evaluation and control of rhizoma Coptidis.

  1. Design and Quasi-Equilibrium Analysis of a Distributed Frequency-Restoration Controller for Inverter-Based Microgrids

    SciTech Connect

    Ainsworth, Nathan G; Grijalva, Prof. Santiago

    2013-01-01

    This paper discusses a proposed frequency restoration controller which operates as an outer loop to frequency droop for voltage-source inverters. By quasi-equilibrium analysis, we show that the proposed controller is able to provide arbitrarily small steady-state frequency error while maintaing power sharing between inverters without need for communication or centralized control. We derive rate of convergence, discuss design considerations (including a fundamental trade-off that must be made in design), present a design procedure to meet a maximum frequency error requirement, and show simulation results verifying our analysis and design method. The proposed controller will allow flexible plug-and-play inverter-based networks to meet a specified maximum frequency error requirement.

  2. Control and communication co-design: analysis and practice on performance improvement in distributed measurement and control system based on fieldbus and Ethernet.

    PubMed

    Liang, Geng

    2015-01-01

    In this paper, improving control performance of a networked control system by reducing DTD in a different perspective was investigated. Two different network architectures for system implementation were presented. Analysis and improvement dealing with DTD for the experimental control system were expounded. Effects of control scheme configuration on DTD in the form of FB were investigated and corresponding improvements by reallocation of FB and re-arrangement of schedule table are proposed. Issues of DTD in hybrid network were investigated and corresponding approaches to improve performance including (1) reducing DTD in PLC or PAC by way of IEC61499 and (2) cascade Smith predictive control with BPNN-based identification were proposed and investigated. Control effects under the proposed methodologies were also given. Experimental and field practices validated these methodologies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Bio-inspired controller for a dexterous prosthetic hand based on Principal Components Analysis.

    PubMed

    Matrone, G; Cipriani, C; Secco, E L; Carrozza, M C; Magenes, G

    2009-01-01

    Controlling a dexterous myoelectric prosthetic hand with many degrees of freedom (DoFs) could be a very demanding task, which requires the amputee for high concentration and ability in modulating many different muscular contraction signals. In this work a new approach to multi-DoF control is proposed, which makes use of Principal Component Analysis (PCA) to reduce the DoFs space dimensionality and allow to drive a 15 DoFs hand by means of a 2 DoFs signal. This approach has been tested and properly adapted to work onto the underactuated robotic hand named CyberHand, using mouse cursor coordinates as input signals and a principal components (PCs) matrix taken from the literature. First trials show the feasibility of performing grasps using this method. Further tests with real EMG signals are foreseen.

  4. Longitudinal control behaviour: Analysis and modelling based on experimental surveys in Italy and the UK.

    PubMed

    Pariota, Luigi; Bifulco, Gennaro Nicola; Galante, Francesco; Montella, Alfonso; Brackstone, Mark

    2016-04-01

    This paper analyses driving behaviour in car-following conditions, based on extensive individual vehicle data collected during experimental field surveys carried out in Italy and the UK. The aim is to contribute to identify simple evidence to be exploited in the ongoing process of driving assistance and automation which, in turn, would reduce rear-end crashes. In particular, identification of differences and similarities in observed car-following behaviours for different samples of drivers could justify common tuning, at a European or worldwide level, of a technological solution aimed at active safety, or, in the event of differences, could suggest the most critical aspects to be taken into account for localisation or customisation of driving assistance solutions. Without intending to be exhaustive, this paper moves one step in this direction. Indeed, driving behaviour and human errors are considered to be among the main crash contributory factors, and a promising approach for safety improvement is the progressive introduction of increasing levels of driving automation in next-generation vehicles, according to the active/preventive safety approach. However, the more advanced the system, the more complex will be the integration in the vehicle, and the interaction with the driver may sometimes become unproductive, or risky, should the driver be removed from the driving control loop. Thus, implementation of these systems will require the interaction of human driving logics with automation logics and then an enhanced ability in modelling drivers' behaviour. This will allow both higher active-safety levels and higher user acceptance to be achieved, thus ensuring that the driver is always in the control loop, even if his/her role is limited to supervising the automatic logic. Currently, the driving mode most targeted by driving assistance systems is longitudinal driving. This is required in various driving conditions, among which car-following assumes key importance

  5. Factors associated with syphilis infection: a comprehensive analysis based on a case-control study.

    PubMed

    Xiao, Y; Li, S-L; Lin, H-L; Lin, Z-F; Zhu, X-Z; Fan, J-Y; Gao, K; Zhang, H-L; Lin, L-R; Liu, L-L; Tong, M-L; Niu, J-J; Yang, T-C

    2016-04-01

    This study aimed to comprehensively evaluate factors that influence the likelihood of syphilis infection from risk-taking behaviours and medical conditions. A retrospective case-control study was conducted by enrolling 664 syphilis inpatients (excluding 11 congenital syphilis patients) and 800 sex- and age-matched controls. Medical histories, clinical data and patient interview data were collected and subjected to logistic regression analyses. The prevalence of syphilis in the study population was 3·9% (675/17,304). By univariate analysis, syphilis infection was associated with migration between cities, marital status, smoking, reproductive history, hypertension, elevated blood urea nitrogen (BUN) and infection with hepatitis B virus (HBV) (P < 0·05). A high rate of syphilis-HBV co-infection was observed in HIV-negative patients and further research revealed an association between syphilis and specific HBV serological reactivity. Syphilis was also associated with the frequency, duration and status of tobacco use. Multivariate analysis indicated that syphilis infection was independently associated with migration between cities [adjusted odds ratio (aOR) 1·368, 95% confidence interval (CI) 1·048-1·785], current smoking (aOR 1·607, 95% CI 1·177-2·195), elevated BUN (aOR 1·782, 95% CI 1·188-2·673) and some serological patterns of HBV infection. To prevent the spread of infectious diseases, inpatients and blood donors should be tested for HIV, syphilis, HBV and HCV simultaneously.

  6. A rule-based system for real-time analysis of control systems

    NASA Technical Reports Server (NTRS)

    Larson, Richard R.; Millard, D. Edward

    1992-01-01

    An approach to automate the real-time analysis of flight critical health monitoring and system status is being developed and evaluated at the NASA Dryden Flight Research Facility. A software package was developed in-house and installed as part of the extended aircraft interrogation and display system. This design features a knowledge-base structure in the form of rules to formulate interpretation and decision logic of real-time data. This technique has been applied for ground verification and validation testing and flight testing monitoring where quick, real-time, safety-of-flight decisions can be very critical. In many cases post processing and manual analysis of flight system data are not required. The processing is described of real-time data for analysis along with the output format which features a message stack display. The development, construction, and testing of the rule-driven knowledge base, along with an application using the X-31A flight test program, are presented.

  7. Stochastic analysis of motor-control stability, polymer based force sensing, and optical stimulation as a preventive measure for falls

    NASA Astrophysics Data System (ADS)

    Landrock, Clinton K.

    Falls are the leading cause of all external injuries. Outcomes of falls include the leading cause of traumatic brain injury and bone fractures, and high direct medical costs in the billions of dollars. This work focused on developing three areas of enabling component technology to be used in postural control monitoring tools targeting the mitigation of falls. The first was an analysis tool based on stochastic fractal analysis to reliably measure levels of motor control. The second focus was on thin film wearable pressure sensors capable of relaying data for the first tool. The third was new thin film advanced optics for improving phototherapy devices targeting postural control disorders. Two populations, athletes and elderly, were studied against control groups. The results of these studies clearly show that monitoring postural stability in at-risk groups can be achieved reliably, and an integrated wearable system can be envisioned for both monitoring and treatment purposes. Keywords: electro-active polymer, ionic polymer-metal composite, postural control, motor control, fall prevention, sports medicine, fractal analysis, physiological signals, wearable sensors, phototherapy, photobiomodulation, nano-optics.

  8. Stability analysis and H infinity controller design of fuzzy large-scale systems based on piecewise Lyapunov functions.

    PubMed

    Zhang, Hongbin; Li, Chunguang; Liao, Xiaofeng

    2006-06-01

    This paper presents a novel approach to stability analysis of a fuzzy large-scale system in which the system is composed of a number of Takagi-Sugeno (T-S) fuzzy subsystems with interconnections. The stability analysis is based on Lyapunov functions that are continuous and piecewise quadratic. It is shown that the stability of the fuzzy large-scale systems can be established if a piecewise Lyapunov function can be constructed, and, moreover, the function can be obtained by solving a set of linear matrix inequalities (LMIs) that are numerically feasible. It is also demonstrated via a numerical example that the stability result based on the piecewise quadratic Lyapunov functions is less conservative than that based on the common quadratic Lyapunov functions. The H infinity controllers can also be designed by solving a set of LMIs based on these powerful piecewise quadratic Lyapunov functions.

  9. A comparative analysis of loop heat pipe based thermal architectures for spacecraft thermal control

    NASA Technical Reports Server (NTRS)

    Pauken, Mike; Birur, Gaj

    2004-01-01

    Loop Heat Pipes (LHP) have gained acceptance as a viable means of heat transport in many spacecraft in recent years. However, applications using LHP technology tend to only remove waste heat from a single component to an external radiator. Removing heat from multiple components has been done by using multiple LHPs. This paper discusses the development and implementation of a Loop Heat Pipe based thermal architecture for spacecraft. In this architecture, a Loop Heat Pipe with multiple evaporators and condensers is described in which heat load sharing and thermal control of multiple components can be achieved. A key element in using a LHP thermal architecture is defining the need for such an architecture early in the spacecraft design process. This paper describes an example in which a LHP based thermal architecture can be used and how such a system can have advantages in weight, cost and reliability over other kinds of distributed thermal control systems. The example used in this paper focuses on a Mars Rover Thermal Architecture. However, the principles described here are applicable to Earth orbiting spacecraft as well.

  10. Improving air pollution control policy in China--A perspective based on cost-benefit analysis.

    PubMed

    Gao, Jinglei; Yuan, Zengwei; Liu, Xuewei; Xia, Xiaoming; Huang, Xianjin; Dong, Zhanfeng

    2016-02-01

    To mitigate serious air pollution, the State Council of China promulgated the Air Pollution Prevention and Control Action Plan in 2013. To verify the feasibility and validity of industrial energy-saving and emission-reduction policies in the action plan, we conducted a cost-benefit analysis of implementing these policies in 31 provinces for the period of 2013 to 2017. We also completed a scenario analysis in this study to assess the cost-effectiveness of different measures within the energy-saving and the emission-reduction policies individually. The data were derived from field surveys, statistical yearbooks, government documents, and published literatures. The results show that total cost and total benefit are 118.39 and 748.15 billion Yuan, respectively, and the estimated benefit-cost ratio is 6.32 in the S3 scenario. For all the scenarios, these policies are cost-effective and the eastern region has higher satisfactory values. Furthermore, the end-of-pipe scenario has greater emission reduction potential than energy-saving scenario. We also found that gross domestic product and population are significantly correlated with the benefit-cost ratio value through the regression analysis of selected possible influencing factors. The sensitivity analysis demonstrates that benefit-cost ratio value is more sensitive to unit emission-reduction cost, unit subsidy, growth rate of gross domestic product, and discount rate among all the parameters. Compared with other provinces, the benefit-cost ratios of Beijing and Tianjin are more sensitive to changes of unit subsidy than unit emission-reduction cost. These findings may have significant implications for improving China's air pollution prevention policy.

  11. Model-Based Analysis and Control of a Network of Basal Ganglia Spiking Neurons in the Normal and Parkinsonian States

    PubMed Central

    Liu, Jianbo; Khalil, Hassan K.; Oweiss, Karim G.

    2011-01-01

    Controlling the spatiotemporal firing pattern of an intricately connected network of neurons through microstimulation is highly desirable in many applications. We investigated in this paper the feasibility of using a model-based approach to the analysis and control of a Basal Ganglia (BG) network model of Hodgkin–Huxley (HH) spiking neurons through microstimulation. Detailed analysis of this network model suggests that it can reproduce the experimentally observed characteristics of BG neurons under a normal and a pathological Parkinsonian state. A simplified neuronal firing rate model, identified from the detailed HH network model, is shown to capture the essential network dynamics. Mathematical analysis of the simplified model reveals the presence of a systematic relationship between the network’s structure and its dynamic response to spatiotemporally patterned microstimulation. We show that both the network synaptic organization and the local mechanism of microstimulation can impose tight constraints on the possible spatiotemporal firing patterns that can be generated by the microstimulated network, which may hinder the effectiveness of microstimulation to achieve a desired objective under certain conditions. Finally, we demonstrate that the feedback control design aided by the mathematical analysis of the simplified model is indeed effective in driving the BG network in the normal and Parskinsonian states to follow a prescribed spatiotemporal firing pattern. We further show that the rhythmic/oscillatory patterns that characterize a dopamine-depleted BG network can be suppressed as a direct consequence of controlling the spatiotemporal pattern of a subpopulation of the output Globus Pallidus internalis (GPi) neurons in the network. This work may provide plausible explanations for the mechanisms underlying the therapeutic effects of Deep Brain Stimulation (DBS) in PD and pave the way towards a model-based, network level analysis and closed-loop control and

  12. Exergy Based Analysis for the Environmental Control and Life Support Systems of the International Space Station

    NASA Technical Reports Server (NTRS)

    Clem, Kirk A.; Nelson, George J.; Mesmer, Bryan L.; Watson, Michael D.; Perry, Jay L.

    2016-01-01

    When optimizing the performance of complex systems, a logical area for concern is improving the efficiency of useful energy. The energy available for a system to perform work is defined as a system's energy content. Interactions between a system's subsystems and the surrounding environment can be accounted for by understanding various subsystem energy efficiencies. Energy balance of reactants and products, and enthalpies and entropies, can be used to represent a chemical process. Heat transfer energy represents heat loads, and flow energy represents system flows and filters. These elements allow for a system level energy balance. The energy balance equations are developed for the subsystems of the Environmental Control and Life Support (ECLS) system aboard the International Space Station (ISS). The use of these equations with system information would allow for the calculation of the energy efficiency of the system, enabling comparisons of the ISS ECLS system to other systems as well as allows for an integrated systems analysis for system optimization.

  13. Model-based analysis and control of a network of basal ganglia spiking neurons in the normal and Parkinsonian states

    NASA Astrophysics Data System (ADS)

    Liu, Jianbo; Khalil, Hassan K.; Oweiss, Karim G.

    2011-08-01

    Controlling the spatiotemporal firing pattern of an intricately connected network of neurons through microstimulation is highly desirable in many applications. We investigated in this paper the feasibility of using a model-based approach to the analysis and control of a basal ganglia (BG) network model of Hodgkin-Huxley (HH) spiking neurons through microstimulation. Detailed analysis of this network model suggests that it can reproduce the experimentally observed characteristics of BG neurons under a normal and a pathological Parkinsonian state. A simplified neuronal firing rate model, identified from the detailed HH network model, is shown to capture the essential network dynamics. Mathematical analysis of the simplified model reveals the presence of a systematic relationship between the network's structure and its dynamic response to spatiotemporally patterned microstimulation. We show that both the network synaptic organization and the local mechanism of microstimulation can impose tight constraints on the possible spatiotemporal firing patterns that can be generated by the microstimulated network, which may hinder the effectiveness of microstimulation to achieve a desired objective under certain conditions. Finally, we demonstrate that the feedback control design aided by the mathematical analysis of the simplified model is indeed effective in driving the BG network in the normal and Parskinsonian states to follow a prescribed spatiotemporal firing pattern. We further show that the rhythmic/oscillatory patterns that characterize a dopamine-depleted BG network can be suppressed as a direct consequence of controlling the spatiotemporal pattern of a subpopulation of the output Globus Pallidus internalis (GPi) neurons in the network. This work may provide plausible explanations for the mechanisms underlying the therapeutic effects of deep brain stimulation (DBS) in Parkinson's disease and pave the way towards a model-based, network level analysis and closed

  14. β-actin as a loading control for plasma-based Western blot analysis of major depressive disorder patients.

    PubMed

    Zhang, Rufang; Yang, Deyu; Zhou, Chanjuan; Cheng, Ke; Liu, Zhao; Chen, Liang; Fang, Liang; Xie, Peng

    2012-08-15

    Western blot analysis is a commonly used technique for determining specific protein levels in clinical samples. For normalization of protein levels in Western blot, a suitable loading control is required. On account of its relatively high and constant expression, β-actin has been widely employed in Western blot of cell cultures and tissue extracts. However, β-actin's presence in human plasma and this protein's putative role as a plasma-based loading control for Western blot analysis remain unknown. In this study, an enzyme-linked immunosorbent assay was used to determine the concentration of β-actin in human plasma, which is 6.29±0.54 ng/ml. In addition, the linearity of β-actin immunostaining and loaded protein amount was evaluated by Western blot, and a fine linearity (R²=0.974±0.012) was observed. Furthermore, the expression of plasma β-actin in major depressive disorder subjects and healthy controls was compared. The data revealed no statistically significant difference between these two groups. Moreover, the total coefficient of variation for β-actin expression in the two groups was 9.2±1.2%. These findings demonstrate that β-actin is present in human plasma and may possibly be used as a suitable loading control for plasma-based Western blot analysis in major depressive disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Controls on aerosol wet deposition from satellite-based (re-)analysis products

    NASA Astrophysics Data System (ADS)

    Chuang, P. Y.

    2015-12-01

    Aerosol wet deposition is the key aerosol loss mechanism globally, yet is not well-understood relative to aerosol sources and transformations. The difficulty in generating appropriate observational data sets is one important barrier to the study of aerosol wet removal. In this study, we combine two independent products based on satellite measurements. Aerosol optical depth (AOD) is obtained from the ECMWF Monitoring Atmospheric Composition and Climate (MACC) project, which is a re-analysis product that assimilates MODIS-retrieved aerosol optical depth. Rainfall is obtained from the Tropical Rainfall Measurement Mission (TRMM) Multi-satellite Precipitation Analysis version 7 (TMPA-7). The latter product is available only from 50°N to 50°S, which sets our region of study. The data used is from 2011-12, is averaged to 6-hr intervals and has a horizontal resolution of 0.25°x0.25°. Our approach involves constructing a Lagrangian advection scheme that predicts aerosol AOD at the next time step (i.e. 6 hr in the future) based on current time step AOD and winds, and neglecting all aerosol sources and sinks. Predicted AOD is then compared with MACC reanalysis AOD conditioned on Lagrangian parcels that experienced rainfall during that interval, with AOD decreases attributed to wet deposition. Aerosol wet deposition is often parameterized in models as a function of rainfall rate using a power law. We evaluate the validity of such a power law relationship, and, when valid, compute the power law exponent globally, and by region (including continental and maritime locations) to reveal seasonal and geographic variability. Assuming precipitation is modulated by aerosol, at least in some regimes, then it follows that wet deposition also depends on AOD, and we quantify the strength of this coupling. This same approach could be used to study wet deposition of trace gases such as CO and ozone, as these are also available from the MACC re-analysis.

  16. Successful Control of Ebola Virus Disease: Analysis of Service Based Data from Rural Sierra Leone.

    PubMed

    Lokuge, Kamalini; Caleo, Grazia; Greig, Jane; Duncombe, Jennifer; McWilliam, Nicholas; Squire, James; Lamin, Manjo; Veltus, Emily; Wolz, Anja; Kobinger, Gary; de la Vega, Marc-Antoine; Gbabai, Osman; Nabieu, Sao; Lamin, Mohammed; Kremer, Ronald; Danis, Kostas; Banks, Emily; Glass, Kathryn

    2016-03-01

    EVD case, EMC capacity increased from 32 to 100 beds, the number of burial teams doubled, and health promotion activities increased in coverage. These improvements in response were associated with the following changes between the same periods: the proportion of confirmed/probable cases admitted to the EMC increased from 35% to 83% (χ(2) p-value<0·001), the proportion of confirmed patients admitted to the EMC <3 days of symptom onset increased from 19% to 37% (χ(2) p-value <0·001), and reported funeral contact in those admitted decreased from 33% to 16% (χ(2) p-value <0·001). Mathematical modelling confirmed the importance of both patient management capacity and surveillance and contact tracing for EVD control. Our findings demonstrate that control of EVD can be achieved using established interventions based on identification and appropriate management of those who are at risk of and develop EVD, including in the context of ongoing transmission in surrounding regions. Key attributes in achieving control were sufficient patient care capacity (including admission to specialist facilities of suspect and probable cases for assessment), integrated with adequate staffing and resourcing of community-based case detection and prevention activities. The response structure and coverage targets we present are of value in informing effective control in current and future EVD outbreaks.

  17. Successful Control of Ebola Virus Disease: Analysis of Service Based Data from Rural Sierra Leone

    PubMed Central

    Lokuge, Kamalini; Caleo, Grazia; Greig, Jane; Duncombe, Jennifer; McWilliam, Nicholas; Squire, James; Lamin, Manjo; Veltus, Emily; Wolz, Anja; Kobinger, Gary; de la Vega, Marc-Antoine; Gbabai, Osman; Nabieu, Sao; Lamin, Mohammed; Kremer, Ronald; Danis, Kostas; Banks, Emily; Glass, Kathryn

    2016-01-01

    from 1.0 to 8.8 per confirmed EVD case, EMC capacity increased from 32 to 100 beds, the number of burial teams doubled, and health promotion activities increased in coverage. These improvements in response were associated with the following changes between the same periods: the proportion of confirmed/probable cases admitted to the EMC increased from 35% to 83% (χ2 p-value<0·001), the proportion of confirmed patients admitted to the EMC <3 days of symptom onset increased from 19% to 37% (χ2 p-value <0·001), and reported funeral contact in those admitted decreased from 33% to 16% (χ2 p-value <0·001). Mathematical modelling confirmed the importance of both patient management capacity and surveillance and contact tracing for EVD control. Discussion Our findings demonstrate that control of EVD can be achieved using established interventions based on identification and appropriate management of those who are at risk of and develop EVD, including in the context of ongoing transmission in surrounding regions. Key attributes in achieving control were sufficient patient care capacity (including admission to specialist facilities of suspect and probable cases for assessment), integrated with adequate staffing and resourcing of community-based case detection and prevention activities. The response structure and coverage targets we present are of value in informing effective control in current and future EVD outbreaks. PMID:26959413

  18. An equation-free approach to agent-based computation: Bifurcation analysis and control of stationary states

    NASA Astrophysics Data System (ADS)

    Siettos, C. I.; Gear, C. W.; Kevrekidis, I. G.

    2012-08-01

    We show how the equation-free approach can be exploited to enable agent-based simulators to perform system-level computations such as bifurcation, stability analysis and controller design. We illustrate these tasks through an event-driven agent-based model describing the dynamic behaviour of many interacting investors in the presence of mimesis. Using short bursts of appropriately initialized runs of the detailed, agent-based simulator, we construct the coarse-grained bifurcation diagram of the (expected) density of agents and investigate the stability of its multiple solution branches. When the mimetic coupling between agents becomes strong enough, the stable stationary state loses its stability at a coarse turning point bifurcation. We also demonstrate how the framework can be used to design a wash-out dynamic controller that stabilizes open-loop unstable stationary states even under model uncertainty.

  19. Analysis of WC/Ni-Based Coatings Deposited by Controlled Short-Circuit MIG Welding

    NASA Astrophysics Data System (ADS)

    Vespa, P.; Pinard, P. T.; Gauvin, R.; Brochu, M.

    2012-06-01

    This study investigates the recently developed controlled short-circuit metal inert gas (CSC-MIG) welding system for depositing WC/Ni-based claddings on carbon steel substrates. WC/Ni-based coatings deposited by CSC-MIG were analyzed by optical light microscopy and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) capabilities. X-ray diffraction (XRD) and hardness measurements of depositions are also reported. The CSC-MIG welding system provides a significant amount of user control over the current waveform during welding and has lower heat input when compared with traditional MIG welding. Heat input for the analyzed coatings ranged from 10.1 to 108.7 J/mm. Metallurgically bonded coatings free from spatter and with 0.75% average porosity were produced. It was found that the detrimental decarburization of the WC particles seen in thermal spray systems does not occur when welding with the CSC-MIG. Precipitation of a reaction layer around the reinforcing phase was identified as WC; the average thickness of which increases from 3.8 to 7.2 μm for the low and high heat input condition, respectively. Precipitation of newly formed WC particles was observed; their size distribution increased from D 50 of 2.4 μm in the low heat input weldment to 6.75 μm in the high heat input weldment. The level of dilution of the reinforcing phase increases significantly with heat input. The hardness of the deposited coatings decreases from 587 HV10 to 410 HV10 when the energy input was increased from 10.1 to 108.7 J/mm.

  20. Control performance of paper-based blood analysis devices through paper structure design.

    PubMed

    Li, Lizi; Huang, Xiaolei; Liu, Wen; Shen, Wei

    2014-12-10

    In this work, we investigated the influence of paper structure on the performance of paper-based analytical devices that are used for blood analysis. The question that we aimed to answer is how the fiber type (i.e., softwood and hardwood fibers) influences the fiber network structure of the paper, which affects the transport of red blood cells (RBCs) in paper. In the experimental design, we isolated the influence of fiber types on the paper structure from all other possible influencing factors by removing the fines from the pulps and not using any additives. Mercury porosimetry was employed to characterize the pore structures of the paper sheets. The results show that papers with a low basis weight that are made with short hardwood fibers have a higher porosity (i.e., void fraction) and simpler pore structures compared with papers made with long softwood fibers. RBC transport in paper carried by saline solution was investigated in two modes: lateral chromatographic elution and vertical flow-through. The results showed that the complexity of the paper's internal pore structure has a dominant influence on the transport of RBCs in paper. Hardwood fiber sheets with a low basis weight have a simple internal pore structure and allow for the easy transport of RBCs. Blood-typing sensors built with low basis weight hardwood fibers deliver high-clarity assays. Softwood fiber papers are found to have a more complex pore structure, which makes RBC transport more difficult, leading to blood-typing results of low clarity. This study provides the principle of paper sheet design for paper-based blood analysis sensors.

  1. Energy consumption analysis of graphene based all spin logic device with voltage controlled magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Zhang, Zhizhong; Zhang, Yue; Zheng, Zhenyi; Wang, Guanda; Su, Li; Zhang, Youguang; Zhao, Weisheng

    2017-05-01

    All spin logic device (ASLD) is a promising option to realize the ultra-low power computing systems. However, the low spin transport efficiency and the non-local switching of the detector have become two key challenges of the ASLD. In this paper, we analyze the energy consumption of a graphene based ASLD with the ferromagnetic layer switching assistance by voltage control magnetic anisotropy (VCMA) effect. This structure has significant potential towards ultra-low power consumption: the applied voltage can not only shorten switching time of the ferromagnetic layer, but also decreases the critical injection current; the graphene channel enhances greatly the spin transport efficiency. By applying the approximate circuit model, the impact of material configurations, interfaces and geometry can be synthetically studied. An accurate physic model was also developed, based on which, we carry out the micro-magnetic simulations to analyze the magnetization dynamics. Combining these electrical and magnetic investigations, the energy consumption of the proposed ASLD can be estimated. With the optimizing parameters, the energy consumption can be reduced to 2.5 pJ for a logic operation.

  2. Space construction base control system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Aspects of an attitude control system were studied and developed for a large space base that is structurally flexible and whose mass properties change rather dramatically during its orbital lifetime. Topics of discussion include the following: (1) space base orbital pointing and maneuvering; (2) angular momentum sizing of actuators; (3) momentum desaturation selection and sizing; (4) multilevel control technique applied to configuration one; (5) one-dimensional model simulation; (6) N-body discrete coordinate simulation; (7) structural analysis math model formulation; and (8) discussion of control problems and control methods.

  3. GPU-based parallel method of temperature field analysis in a floor heater with a controller

    NASA Astrophysics Data System (ADS)

    Forenc, Jaroslaw

    2016-06-01

    A parallel method enabling acceleration of the numerical analysis of the transient temperature field in an air floor heating system is presented in this paper. An initial-boundary value problem of the heater regulated by an on/off controller is formulated. The analogue model is discretized using the implicit finite difference method. The BiCGStab method is used to compute the obtained system of equations. A computer program implementing simultaneous computations on CPUand GPU(GPGPUtechnology) was developed. CUDA environment and linear algebra libraries (CUBLAS and CUSPARSE) are used by this program. The time of computations was reduced eight times in comparison with a program executed on the CPU only. Results of computations are presented in the form of time profiles and temperature field distributions. An influence of a model of the heat transfer coefficient on the simulation of the system operation was examined. The physical interpretation of obtained results is also presented.Results of computations were verified by comparing them with solutions obtained with the use of a commercial program - COMSOL Mutiphysics.

  4. Transient-Free Operations With Physics-Based Real-time Analysis and Control

    NASA Astrophysics Data System (ADS)

    Kolemen, Egemen; Burrell, Keith; Eggert, William; Eldon, David; Ferron, John; Glasser, Alex; Humphreys, David

    2016-10-01

    In order to understand and predict disruptions, the two most common methods currently employed in tokamak analysis are the time-consuming ``kinetic EFITs,'' which are done offline with significant human involvement, and the search for correlations with global precursors using various parameterization techniques. We are developing automated ``kinetic EFITs'' at DIII-D to enable calculation of the stability as the plasma evolves close to the disruption. This allows us to quantify the probabilistic nature of the stability calculations and provides a stability metric for all possible linear perturbations to the plasma. This study also provides insight into how the control system can avoid the unstable operating space, which is critical for high-performance operations close to stability thresholds at ITER. A novel, efficient ideal stability calculation method and new real-time CER acquisition system are being developed, and a new 77-core server has been installed on the DIII-D PCS to enable experimental use. Sponsored by US DOE under DE-SC0015878 and DE-FC02-04ER54698.

  5. Analysis of the Route-Based Aggregate Model for Strategic Air Traffic Control

    NASA Astrophysics Data System (ADS)

    De Los Santos Bernad, Victor

    Because of the vital importance of the National Airspace System (NAS) and its diagnosed growth over the next years, the planning and prediction at a strategic phase of the Traffic Flow Management (TFM) proves to be a difficult task but a useful tool to reduce the airspace congestion. Research has led to the creation of several models in order to address this challenge. Because of the complexity of the problem, the Eulerian (aggregate) approach may be the best to reduce the dimension and complexity of the problem, whilst maintaining accuracy. This study analyzes one of the latest aggregate models created, the Route-Based Aggregate Model (RBAM), and compares it to the Large-Capacity Cell Transmission Model (CTM(L)) and the Link Transmission Model (LTM). These three models share some similarities such as the non-existence of diverging nodes or, in the case of the CTM(L), the condition of submitting all the airplanes in a cell to the next cell after one time-stepBut there are also big differences which make them different enough to coexist. For example, the RBAM can be used without the need of historical data in order to model the NAS, only the information of the upcoming flight plans. Also, the RBAM is designed to base its controls from a ground perspective, allowing ground rerouting and ground delay. An explanation on how to implement the RBAM in Matlab can be found in this project, explaining the peculiarities of the translation of the cost function constraints into a Linear Programming (LP) problem, with several examples that show how the solution to the LP problem distributes the delays between ground delays and ground reroutings. Because the cost of a ground rerouting is different from the cost of a ground delay because of the extra fuel expense that the rerouting may cause (assuming always that the original route is shorter), a proper weighting of both controls is found, considering different variables such as the cost of the fuel or the cost of overtime parking

  6. Computational Design and Analysis of a Micro-Tab Based Aerodynamic Loads Control System for Lifting Surfaces

    SciTech Connect

    Van Dam, C P; Nakafuji, D Y; Bauer, C; Chao, D; Standish, K

    2002-11-01

    A computational design and analysis of a microtab based aerodynamic loads control system is presented. The microtab consists of a small tab that emerges from a wing approximately perpendicular to its surface in the vicinity of its trailing edge. Tab deployment on the upper side of the wing causes a decrease in the lift generation whereas deployment on the pressure side causes an increase. The computational methods applied in the development of this concept solve the governing Reynolds-averaged Navier-Stokes equations on structured, overset grids. The application of these methods to simulate the flows over lifting surface including the tabs has been paramount in the development of these devices. The numerical results demonstrate the effectiveness of the microtab and that it is possible to carry out a sensitivity analysis on the positioning and sizing of the tabs before they are implemented in successfully controlling the aerodynamic loads.

  7. A Clustering Based Approach for Observability and Controllability Analysis for Optimal Placement of PMU

    NASA Astrophysics Data System (ADS)

    Murthy, Ch; MIEEE; Mohanta, D. K.; SMIEE; Meher, Mahendra

    2017-08-01

    Continuous monitoring and control of the power system is essential for its healthy operation. This can be achieved by making the system observable as well as controllable. Many efforts have been made by several researchers to make the system observable by placing the Phasor Measurement Units (PMUs) at the optimal locations. But so far the idea of controllability with PMUs is not considered. This paper contributes how to check whether the system is controllable or not, if not then how make it controllable using a clustering approach. IEEE 14 bus system is considered to illustrate the concept of controllability.

  8. Mechanical and biomechanical analysis of a linear piston design for angular-velocity-based orthotic control.

    PubMed

    Lemaire, Edward D; Samadi, Reza; Goudreau, Louis; Kofman, Jonathan

    2013-01-01

    A linear piston hydraulic angular-velocity-based control knee joint was designed for people with knee-extensor weakness to engage knee-flexion resistance when knee-flexion angular velocity reaches a preset threshold, such as during a stumble, but to otherwise allow free knee motion. During mechanical testing at the lowest angular-velocity threshold, the device engaged within 2 degrees knee flexion and resisted moment loads of over 150 Nm. The device completed 400,000 loading cycles without mechanical failure or wear that would affect function. Gait patterns of nondisabled participants were similar to normal at walking speeds that produced below-threshold knee angular velocities. Fast walking speeds, employed purposely to attain the angular-velocity threshold and cause knee-flexion resistance, reduced maximum knee flexion by approximately 25 degrees but did not lead to unsafe gait patterns in foot ground clearance during swing. In knee collapse tests, the device successfully engaged knee-flexion resistance and stopped knee flexion with peak knee moments of up to 235.6 Nm. The outcomes from this study support the potential for the linear piston hydraulic knee joint in knee and knee-ankle-foot orthoses for people with lower-limb weakness.

  9. Detection of Impaired Sympathetic Cerebrovascular Control Using Functional Biomarkers Based on Principal Dynamic Mode Analysis

    PubMed Central

    Saleem, Saqib; Tzeng, Yu-Chieh; Kleijn, W. Bastiaan; Teal, Paul D.

    2017-01-01

    This study sought to determine whether models of cerebrovascular function based on Laguerre-Volterra kernels that account for nonlinear cerebral blood flow (CBF) dynamics can detect the effects of functional cerebral sympathetic blockade. We retrospectively analyzed continuous beat-to-beat blood pressure, middle cerebral blood velocity, and partial-pressure of end-tidal CO2 (PETCO2) recordings from eighteen healthy individuals who were treated with either an oral dose of the α1-adrenergic receptor blocker Prazosin or a placebo treatment. The global principal dynamic modes (PDMs) were analyzed using Laguerre-Volterra kernels to examine the nonlinear system dynamics. Our principal findings were: (1) very low frequency (<0.03 Hz) linear components of first-order kernels for BP and PETCO2 are mutually coupled to CBF dynamics with the ability to separate individuals between control and blockade conditions, and (2) the gains of the nonlinear functions associated with low-pass and ≈0.03 Hz global PDMs for the BP are sensitive to sympathetic blockade. Collectively these results suggest that very low frequency global PDMs for BP may have potential utility as functional biomarkers of sympathetic neurovascular dysfunction which can occur in conditions like autonomic failure, stroke and traumatic brain injury. PMID:28119628

  10. 78 FR 64735 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ...The Food and Drug Administration (FDA) is proposing regulations for domestic and foreign facilities that are required to register under the Federal Food, Drug, and Cosmetic Act (the FD&C Act) to establish requirements for current good manufacturing practice in manufacturing, processing, packing, and holding of animal food. FDA also is proposing regulations to require that certain facilities establish and implement hazard analysis and risk-based preventive controls for food for animals. FDA is taking this action to provide greater assurance that animal food is safe and will not cause illness or injury to animals or humans and is intended to build an animal food safety system for the future that makes modern, science and risk-based preventive controls the norm across all sectors of the animal food system.

  11. Spectroscopic analysis and control

    DOEpatents

    Tate; , James D.; Reed, Christopher J.; Domke, Christopher H.; Le, Linh; Seasholtz, Mary Beth; Weber, Andy; Lipp, Charles

    2017-04-18

    Apparatus for spectroscopic analysis which includes a tunable diode laser spectrometer having a digital output signal and a digital computer for receiving the digital output signal from the spectrometer, the digital computer programmed to process the digital output signal using a multivariate regression algorithm. In addition, a spectroscopic method of analysis using such apparatus. Finally, a method for controlling an ethylene cracker hydrogenator.

  12. Interactive Controls Analysis (INCA)

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H.

    1989-01-01

    Version 3.12 of INCA provides user-friendly environment for design and analysis of linear control systems. System configuration and parameters easily adjusted, enabling INCA user to create compensation networks and perform sensitivity analysis in convenient manner. Full complement of graphical routines makes output easy to understand. Written in Pascal and FORTRAN.

  13. Interactive Controls Analysis (INCA)

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H.

    1989-01-01

    Version 3.12 of INCA provides user-friendly environment for design and analysis of linear control systems. System configuration and parameters easily adjusted, enabling INCA user to create compensation networks and perform sensitivity analysis in convenient manner. Full complement of graphical routines makes output easy to understand. Written in Pascal and FORTRAN.

  14. Model based manipulator control

    NASA Technical Reports Server (NTRS)

    Petrosky, Lyman J.; Oppenheim, Irving J.

    1989-01-01

    The feasibility of using model based control (MBC) for robotic manipulators was investigated. A double inverted pendulum system was constructed as the experimental system for a general study of dynamically stable manipulation. The original interest in dynamically stable systems was driven by the objective of high vertical reach (balancing), and the planning of inertially favorable trajectories for force and payload demands. The model-based control approach is described and the results of experimental tests are summarized. Results directly demonstrate that MBC can provide stable control at all speeds of operation and support operations requiring dynamic stability such as balancing. The application of MBC to systems with flexible links is also discussed.

  15. Analysis of CDC social control measures using an agent-based simulation of an influenza epidemic in a city.

    PubMed

    Yang, Yong; Atkinson, Peter M; Ettema, Dick

    2011-07-18

    The transmission of infectious disease amongst the human population is a complex process which requires advanced, often individual-based, models to capture the space-time details observed in reality. An Individual Space-Time Activity-based Model (ISTAM) was applied to simulate the effectiveness of non-pharmaceutical control measures including: (1) refraining from social activities, (2) school closure and (3) household quarantine, for a hypothetical influenza outbreak in an urban area. Amongst the set of control measures tested, refraining from social activities with various compliance levels was relatively ineffective. Household quarantine was very effective, especially for the peak number of cases and total number of cases, with large differences between compliance levels. Household quarantine resulted in a decrease in the peak number of cases from more than 300 to around 158 for a 100% compliance level, a decrease of about 48.7%. The delay in the outbreak peak was about 3 to 17 days. The total number of cases decreased to a range of 3635-5403, that is, 63.7%-94.7% of the baseline value. When coupling control measures, household quarantine together with school closure was the most effective strategy. The resulting space-time distribution of infection in different classes of activity bundles (AB) suggests that the epidemic outbreak is strengthened amongst children and then spread to adults. By sensitivity analysis, this study demonstrated that earlier implementation of control measures leads to greater efficacy. Also, for infectious diseases with larger basic reproduction number, the effectiveness of non-pharmaceutical measures was shown to be limited. Simulated results showed that household quarantine was the most effective control measure, while school closure and household quarantine implemented together achieved the greatest benefit. Agent-based models should be applied in the future to evaluate the efficacy of control measures for a range of disease outbreaks

  16. Structural Technology Evaluation and Analysis Program (STEAP). Delivery Order 0037: Prognosis-Based Control Reconfiguration for an Aircraft with Faulty Actuator to Enable Performance in a Degraded State

    DTIC Science & Technology

    2010-12-01

    AFRL-RB-WP-TR-2010-3109 STRUCTURAL TECHNOLOGY EVALUATION AND ANALYSIS PROGRAM (STEAP) Delivery Order 0037: Prognosis-Based Control ...a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1...STRUCTURAL TECHNOLOGY EVALUATION AND ANALYSIS PROGRAM (STEAP) Delivery Order 0037: Prognosis-Based Control Reconfiguration for an Aircraft with

  17. Cost-effectiveness analysis of population-based tobacco control strategies in the prevention of cardiovascular diseases in Tanzania

    PubMed Central

    Ngalesoni, Frida; Ruhago, George; Mayige, Mary; Oliveira, Tiago Cravo; Robberstad, Bjarne; Norheim, Ole Frithjof; Higashi, Hideki

    2017-01-01

    Background Tobacco consumption contributes significantly to the global burden of disease. The prevalence of smoking is estimated to be increasing in many low-income countries, including Tanzania, especially among women and youth. Even so, the implementation of tobacco control measures has been discouraging in the country. Efforts to foster investment in tobacco control are hindered by lack of evidence on what works and at what cost. Aims We aim to estimate the cost and cost-effectiveness of population-based tobacco control strategies in the prevention of cardiovascular diseases (CVD) in Tanzania. Materials and methods A cost-effectiveness analysis was performed using an Excel-based Markov model, from a governmental perspective. We employed an ingredient approach and step-down methodologies in the costing exercise following a government perspective. Epidemiological data and efficacy inputs were derived from the literature. We used disability-adjusted life years (DALYs) averted as the outcome measure. A probabilistic sensitivity analysis was carried out with Ersatz to incorporate uncertainties in the model parameters. Results Our model results showed that all five tobacco control strategies were very cost-effective since they fell below the ceiling ratio of one GDP per capita suggested by the WHO. Increase in tobacco taxes was the most cost-effective strategy, while a workplace smoking ban was the least cost-effective option, with a cost-effectiveness ratio of US$5 and US$267, respectively. Conclusions Even though all five interventions are deemed very cost-effective in the prevention of CVD in Tanzania, more research on budget impact analysis is required to further assess the government’s ability to implement these interventions. PMID:28767722

  18. Cost-effectiveness analysis of population-based tobacco control strategies in the prevention of cardiovascular diseases in Tanzania.

    PubMed

    Ngalesoni, Frida; Ruhago, George; Mayige, Mary; Oliveira, Tiago Cravo; Robberstad, Bjarne; Norheim, Ole Frithjof; Higashi, Hideki

    2017-01-01

    Tobacco consumption contributes significantly to the global burden of disease. The prevalence of smoking is estimated to be increasing in many low-income countries, including Tanzania, especially among women and youth. Even so, the implementation of tobacco control measures has been discouraging in the country. Efforts to foster investment in tobacco control are hindered by lack of evidence on what works and at what cost. We aim to estimate the cost and cost-effectiveness of population-based tobacco control strategies in the prevention of cardiovascular diseases (CVD) in Tanzania. A cost-effectiveness analysis was performed using an Excel-based Markov model, from a governmental perspective. We employed an ingredient approach and step-down methodologies in the costing exercise following a government perspective. Epidemiological data and efficacy inputs were derived from the literature. We used disability-adjusted life years (DALYs) averted as the outcome measure. A probabilistic sensitivity analysis was carried out with Ersatz to incorporate uncertainties in the model parameters. Our model results showed that all five tobacco control strategies were very cost-effective since they fell below the ceiling ratio of one GDP per capita suggested by the WHO. Increase in tobacco taxes was the most cost-effective strategy, while a workplace smoking ban was the least cost-effective option, with a cost-effectiveness ratio of US$5 and US$267, respectively. Even though all five interventions are deemed very cost-effective in the prevention of CVD in Tanzania, more research on budget impact analysis is required to further assess the government's ability to implement these interventions.

  19. Process monitoring and control with CHEMIN, a miniaturized CCD-based instrument for simultaneous XRD/XRF analysis

    NASA Astrophysics Data System (ADS)

    Vaniman, David T.; Bish, D.; Guthrie, G.; Chipera, S.; Blake, David E.; Collins, S. Andy; Elliott, S. T.; Sarrazin, P.

    1999-10-01

    There is a large variety of mining and manufacturing operations where process monitoring and control can benefit from on-site analysis of both chemical and mineralogic constituents. CHEMIN is a CCD-based instrument capable of both X-ray fluorescence (XRF; chemical) and X-ray diffraction (XRD; mineralogic) analysis. Monitoring and control with an instrument like CHEMIN can be applied to feedstocks, intermediate materials, and final products to optimize production. Examples include control of cement feedstock, of ore for smelting, and of minerals that pose inhalation hazards in the workplace. The combined XRD/XRF capability of CHEMIN can be used wherever a desired commodity is associated with unwanted constituents that may be similar in chemistry or structure but not both (e.g., Ca in both gypsum and feldspar, where only the gypsum is desired to make wallboard). In the mining industry, CHEMIN can determine mineral abundances on the spot and enable more economical mining by providing the means to assay when is being mined, quickly and frequently, at minimal cost. In manufacturing, CHEMIN could be used to spot-check the chemical composition and crystalline makeup of a product at any stage of production. Analysis by CHEMIN can be used as feedback in manufacturing processes where rates of heating, process temperature, mixture of feedstocks, and other variables must be adjusted in real time to correct structure and/or chemistry of the product (e.g., prevention of periclase and alkali sulfate coproduction in cement manufacture).

  20. Model-Based Integrated High Penetration Renewables Planning and Control Analysis

    SciTech Connect

    Bank, Jason; Broadwater, Robert; Cheng, Danling; Costyk, David; Leyo, Mark; Seguin, Richard; Woyak, Jeremy; Acharya-Menon, Amrita; Steffel, Steve; Dise, John; Athawale, Rasika; Felder, Frank

    2015-12-14

    Increasing adoption of Solar Photovoltaic (PV) generation at the distribution level poses several changes for the reliable operation of electrical power distribution systems. The addition of a significant amount of PV to a distribution network can introduce a variety of operational problems, including steady-state overvoltages, reverse flows, voltage flicker and excessive controller movement among others. These adverse impacts can be mitigated through a variety of equipment upgrades which represent a cost to either the electric utility or the owner of the PV site. The study performed here aims to quantify the levels of PV generation which present operational problems on a distribution circuit and how those problems might be alleviated. The study performed here included 20 distribution feeders selected from Pepco Holdings, Inc. (PHI) service territory. These feeders are located in the states of Delaware, Maryland and New Jersey. A hosting capacity study was performed on each feeder to determine how much additional PV it could support in its current configuration. Several improvements were then performed on these circuits including phase balancing, capacitor redesign, reducing the voltage regulator set points, fixed power factor operation on the PV inverters and the installation of battery storage. After each of these improvements the hosting capacity of the circuit was reevaluated in order to determine how that particular improvement impacted the amount of PV that could be hosted by the circuit. Each of these improvements represents a real cost in terms of labor and equipment in order to be implemented. They are expected to provide a benefit in terms of the amount of additional PV generation which can be safely interconnected to the distribution feeder. A cost benefit analysis was performed in order to evaluate the expected costs of each feeder improvement and how each one was able to increase the PV hosting capacity of each feeder. It is hoped that these results

  1. Network-based regularization for matched case-control analysis of high-dimensional DNA methylation data.

    PubMed

    Sun, Hokeun; Wang, Shuang

    2013-05-30

    The matched case-control designs are commonly used to control for potential confounding factors in genetic epidemiology studies especially epigenetic studies with DNA methylation. Compared with unmatched case-control studies with high-dimensional genomic or epigenetic data, there have been few variable selection methods for matched sets. In an earlier paper, we proposed the penalized logistic regression model for the analysis of unmatched DNA methylation data using a network-based penalty. However, for popularly applied matched designs in epigenetic studies that compare DNA methylation between tumor and adjacent non-tumor tissues or between pre-treatment and post-treatment conditions, applying ordinary logistic regression ignoring matching is known to bring serious bias in estimation. In this paper, we developed a penalized conditional logistic model using the network-based penalty that encourages a grouping effect of (1) linked Cytosine-phosphate-Guanine (CpG) sites within a gene or (2) linked genes within a genetic pathway for analysis of matched DNA methylation data. In our simulation studies, we demonstrated the superiority of using conditional logistic model over unconditional logistic model in high-dimensional variable selection problems for matched case-control data. We further investigated the benefits of utilizing biological group or graph information for matched case-control data. We applied the proposed method to a genome-wide DNA methylation study on hepatocellular carcinoma (HCC) where we investigated the DNA methylation levels of tumor and adjacent non-tumor tissues from HCC patients by using the Illumina Infinium HumanMethylation27 Beadchip. Several new CpG sites and genes known to be related to HCC were identified but were missed by the standard method in the original paper. Copyright © 2012 John Wiley & Sons, Ltd.

  2. Efficacy of theory-based interventions to promote physical activity. A meta-analysis of randomised controlled trials.

    PubMed

    Gourlan, M; Bernard, P; Bortolon, C; Romain, A J; Lareyre, O; Carayol, M; Ninot, G; Boiché, J

    2016-01-01

    Implementing theory-based interventions is an effective way to influence physical activity (PA) behaviour in the population. This meta-analysis aimed to (1) determine the global effect of theory-based randomised controlled trials dedicated to the promotion of PA among adults, (2) measure the actual efficacy of interventions against their theoretical objectives and (3) compare the efficacy of single- versus combined-theory interventions. A systematic search through databases and review articles was carried out. Our results show that theory-based interventions (k = 82) significantly impact the PA behaviour of participants (d = 0.31, 95% CI [0.24, 0.37]). While moderation analyses revealed no efficacy difference between theories, interventions based on a single theory (d = 0.35; 95% CI [0.26, 0.43]) reported a higher impact on PA behaviour than those based on a combination of theories (d = 0.21; 95% CI [0.11, 0.32]). In spite of the global positive effect of theory-based interventions on PA behaviour, further research is required to better identify the specificities, overlaps or complementarities of the components of interventions based on relevant theories.

  3. Vision-based drone flight control and crowd or riot analysis with efficient color histogram based tracking

    NASA Astrophysics Data System (ADS)

    Müller, Thomas; Müller, Markus

    2011-05-01

    Object tracking is a direct or indirect key issue in many different military applications like visual surveillance, automatic visual closed-loop control of UAVs (unmanned aerial vehicles) and PTZ-cameras, or in the field of crowd evaluations in order to detect or analyse a riot emergence. Of course, a high robustness is the most important feature of the underlying tracker, but this is hindered significantly the more the tracker needs to have low calculation times. In the UAV application introduced in this paper the tracker has to be extraordinarily quick. In order to optimize the calculation time and the robustness in combination as far as possible, a highly efficient tracking procedure is presented for the above mentioned application fields which relies on well-known color histograms but uses them in a novel manner. This procedure bases on the calculation of a color weighting vector representing the significances of object colors like a kind of an object's color finger print. Several examples from the above mentioned military applications are shown to demonstrate the practical relevance and the performance of the presented tracking approach.

  4. Increased risk of orofacial clefts associated with maternal obesity: case–control study and Monte Carlo-based bias analysis

    PubMed Central

    Stott-Miller, Marni; Heike, Carrie L.; Kratz, Mario; Starr, Jacqueline R.

    2010-01-01

    Summary Our objective was to evaluate whether infants born to obese or diabetic women are at higher risk of non-syndromic orofacial clefting. We conducted a population-based case–control study using Washington State birth certificate and hospitalisation data for the years 1987–2005. Cases were infants born with orofacial clefts (n = 2153) and controls infants without orofacial clefts (n = 18 070). The primary exposures were maternal obesity (body mass index ≥30) and diabetes (either pre-existing or gestational). We estimated adjusted odds ratios (ORs) to compare, for mothers of cases and controls, the proportions of obese vs. normal-weight women and diabetic vs. non-diabetic women. We additionally performed Monte Carlo-based simulation analysis to explore possible influences of biases. Obese women had a small increased risk of isolated orofacial clefts in their offspring compared with normal-body mass index women [adjusted OR 1.26; 95% confidence interval 1.03, 1.55]. Results were similar regardless of type of cleft. Bias analyses suggest that estimates may represent underlying ORs of stronger magnitude. Results for diabetic women were highly imprecise and inconsistent. We and others have observed weak associations of similar magnitude between maternal obesity and risk of nonsyndromic orofacial clefts. These results could be due to bias or residual confounding. However, it is also possible that these results represent a stronger underlying association. More precise exposure measurement could help distinguish between these two possibilities. PMID:20670231

  5. Performance analysis of electronic power transformer based on neuro-fuzzy controller.

    PubMed

    Acikgoz, Hakan; Kececioglu, O Fatih; Yildiz, Ceyhun; Gani, Ahmet; Sekkeli, Mustafa

    2016-01-01

    In recent years, electronic power transformer (EPT), which is also called solid state transformer, has attracted great interest and has been used in place of the conventional power transformers. These transformers have many important functions as high unity power factor, low harmonic distortion, constant DC bus voltage, regulated output voltage and compensation capability. In this study, proposed EPT structure contains a three-phase pulse width modulation rectifier that converts 800 Vrms AC to 2000 V DC bus at input stage, a dual active bridge converter that provides 400 V DC bus with 5:1 high frequency transformer at isolation stage and a three-phase two level inverter that is used to obtain AC output at output stage. In order to enhance dynamic performance of EPT structure, neuro fuzzy controllers which have durable and nonlinear nature are used in input and isolation stages instead of PI controllers. The main aim of EPT structure with the proposed controller is to improve the stability of power system and to provide faster response against disturbances. Moreover, a number of simulation results are carried out to verify EPT structure designed in MATLAB/Simulink environment and to analyze compensation ability for voltage harmonics, voltage flicker and voltage sag/swell conditions.

  6. Broadband network on-line data acquisition system with web based interface for control and basic analysis

    NASA Astrophysics Data System (ADS)

    Polkowski, Marcin; Grad, Marek

    2016-04-01

    Passive seismic experiment "13BB Star" is operated since mid 2013 in northern Poland and consists of 13 broadband seismic stations. One of the elements of this experiment is dedicated on-line data acquisition system comprised of both client (station) side and server side modules with web based interface that allows monitoring of network status and provides tools for preliminary data analysis. Station side is controlled by ARM Linux board that is programmed to maintain 3G/EDGE internet connection, receive data from digitizer, send data do central server among with additional auxiliary parameters like temperatures, voltages and electric current measurements. Station side is controlled by set of easy to install PHP scripts. Data is transmitted securely over SSH protocol to central server. Central server is a dedicated Linux based machine. Its duty is receiving and processing all data from all stations including auxiliary parameters. Server side software is written in PHP and Python. Additionally, it allows remote station configuration and provides web based interface for user friendly interaction. All collected data can be displayed for each day and station. It also allows manual creation of event oriented plots with different filtering abilities and provides numerous status and statistic information. Our solution is very flexible and easy to modify. In this presentation we would like to share our solution and experience. National Science Centre Poland provided financial support for this work via NCN grant DEC-2011/02/A/ST10/00284.

  7. Miniaturized MEMS-based spectrometric sensor for process control and analysis of carbonated beverages

    NASA Astrophysics Data System (ADS)

    Kenda, A.; Kraft, M.; Tortschanoff, A.; Wagner, Ch.; Lendl, B.; Sandner, T.; Schenk, H.

    2010-02-01

    With MEMS, it became possible to build pocket-sized spectrometers for various spectral ranges, including the near-IR or mid-IR. These systems are highly rugged and can measure spectral changes at ms time resolution or co-add several hundreds of scans to one spectrum achieving adequate signal-to-noise ratios. Two spectrometer systems a scanning grating based spectrometer and a FT-IR spectrometer both based on a micromechanical scanning mirror technology are presented. Furthermore, the focus of this work is on the development of an analyzer for dissolved CO2 showing the methodology and also first implementation steps towards a sensor solution. CO2(aq) calibration samples were prepared by different NaHCO3 concentrations in solution. Spectra and calibration data acquired with both MEMS based spectrometer prototypes are presented.

  8. Knowledge-Based System Analysis and Control Defense Switched Network Task Areas

    DTIC Science & Technology

    1987-09-30

    and contained in a file identified by the tag ,sw, is designed to provide data for 18 analysis by those evaluating damage scenarios and the effects...caused by an apparent design error in the routing tables. 4.2 Network Management Goals With respect to damage and overload scenarios we assume that...It is used along with traffic estimates to design the network routing tables and trunk sizing. It measures the probability that a call attempt will

  9. Real-time fMRI-based activation analysis and stimulus control

    NASA Astrophysics Data System (ADS)

    Moench, Tobias; Hollmann, Maurice; Bernarding, Johannes

    2007-03-01

    The real-time analysis of brain activation using functional MRI data offers a wide range of new experiments such as investigating self-regulation or learning strategies. However, besides special data acquisition and real-time data analysing techniques such examination requires dynamic and adaptive stimulus paradigms and self-optimising MRI-sequences. This paper presents an approach that enables the unified handling of parameters influencing the different software systems involved in the acquisition and analysing process. By developing a custom-made Experiment Description Language (EDL) this concept is used for a fast and flexible software environment which treats aspects like extraction and analysis of activation as well as the modification of the stimulus presentation. We describe how extracted real-time activation is subsequently evaluated by comparing activation patterns to previous acquired templates representing activated regions of interest for different predefined conditions. According to those results the stimulus presentation is adapted. The results showed that the developed system in combination with EDL is able to reliably detect and evaluate activation patterns in real-time. With a processing time for data analysis of about one second the approach is only limited by the natural time course of the hemodynamic response function of the brain activation.

  10. Movement Variability Near Goal Equivalent Manifolds: Fluctuations, Control, and Model-Based Analysis

    PubMed Central

    Cusumano, Joseph P.; Dingwell, Jonathan B.

    2013-01-01

    Fluctuations in the repeated performance of human movements have been the subject of intense scrutiny because they are generally believed to contain important information about the function and health of the neuromotor system. A variety of approaches has been brought to bear to study of these fluctuations, however it is frequently difficult to understand how to synthesize different perspectives to give a coherent picture. Here, we describe a conceptual framework for the experimental study of motor variability that helps to unify geometrical methods, which focus on the role of motor redundancy, with dynamical methods that characterize the error-correcting processes regulating the performance of skilled tasks. We describe how goal functions, which mathematically specify the task strategy being employed, together with ideas from the control of redundant systems, allow one to formulate simple, experimentally testable dynamical models of inter-trial fluctuations. After reviewing the basic theory, we present a list of five general hypotheses on the structure of uctuations that can be expected in repeated trials of goal-directed tasks. We review recent experimental applications of this general approach, and show how it can be used to precisely characterize the error-correcting control used by human subjects. PMID:24210574

  11. Weld analysis and control system

    NASA Technical Reports Server (NTRS)

    Kennedy, Larry Z. (Inventor); Rodgers, Michael H. (Inventor); Powell, Bradley W. (Inventor); Burroughs, Ivan A. (Inventor); Goode, K. Wayne (Inventor)

    1994-01-01

    The invention is a Weld Analysis and Control System developed for active weld system control through real time weld data acquisition. Closed-loop control is based on analysis of weld system parameters and weld geometry. The system is adapted for use with automated welding apparatus having a weld controller which is capable of active electronic control of all aspects of a welding operation. Enhanced graphics and data displays are provided for post-weld analysis. The system provides parameter acquisition, including seam location which is acquired for active torch cross-seam positioning. Torch stand-off is also monitored for control. Weld bead and parent surface geometrical parameters are acquired as an indication of weld quality. These parameters include mismatch, peaking, undercut, underfill, crown height, weld width, puddle diameter, and other measurable information about the weld puddle regions, such as puddle symmetry, etc. These parameters provide a basis for active control as well as post-weld quality analysis and verification. Weld system parameters, such as voltage, current and wire feed rate, are also monitored and archived for correlation with quality parameters.

  12. Split-belt controllable treadmill with differential velocity-based fall stimulation and motion analysis.

    PubMed

    Nakashima, Yasutaka; Noutsuka, Hiroki; Fukui, Takanori; Yamamoto, Motoji

    2016-08-01

    Amid trends toward aging populations in developed nations, the number of people requiring nursing care has increased markedly. Slips and falls during ordinary daily activities are a common cause of fractured bones and muscle injury. Several studies have analyzed the movements produced by artificially generated slip and fall stimuli, but few have investigated these stimuli. We analyzed lower-limb motion following a slip and fall stimulus produced using a pulled free-walking system consisting of a controllable split-belt treadmill, where a speed difference between the belts could be applied to produce a slipping motion. In three male participants, we established slip motion by applying acceleration in the sagittal plane direction of the right leg immediately upon contact with the treadmill. Each participant demonstrated a different recovery method from falling.

  13. Aptamer-based analysis: a promising alternative for food safety control.

    PubMed

    Amaya-González, Sonia; de-los-Santos-Alvarez, Noemí; Miranda-Ordieres, Arturo J; Lobo-Castañón, Maria Jesús

    2013-11-28

    Ensuring food safety is nowadays a top priority of authorities and professional players in the food supply chain. One of the key challenges to determine the safety of food and guarantee a high level of consumer protection is the availability of fast, sensitive and reliable analytical methods to identify specific hazards associated to food before they become a health problem. The limitations of existing methods have encouraged the development of new technologies, among them biosensors. Success in biosensor design depends largely on the development of novel receptors with enhanced affinity to the target, while being stable and economical. Aptamers fulfill these characteristics, and thus have surfaced as promising alternatives to natural receptors. This Review describes analytical strategies developed so far using aptamers for the control of pathogens, allergens, adulterants, toxins and other forbidden contaminants to ensure food safety. The main progresses to date are presented, highlighting potential prospects for the future.

  14. Aptamer-Based Analysis: A Promising Alternative for Food Safety Control

    PubMed Central

    Amaya-González, Sonia; de-los-Santos-Álvarez, Noemí; Miranda-Ordieres, Arturo J.; Lobo-Castañón, Maria Jesús

    2013-01-01

    Ensuring food safety is nowadays a top priority of authorities and professional players in the food supply chain. One of the key challenges to determine the safety of food and guarantee a high level of consumer protection is the availability of fast, sensitive and reliable analytical methods to identify specific hazards associated to food before they become a health problem. The limitations of existing methods have encouraged the development of new technologies, among them biosensors. Success in biosensor design depends largely on the development of novel receptors with enhanced affinity to the target, while being stable and economical. Aptamers fulfill these characteristics, and thus have surfaced as promising alternatives to natural receptors. This Review describes analytical strategies developed so far using aptamers for the control of pathogens, allergens, adulterants, toxins and other forbidden contaminants to ensure food safety. The main progresses to date are presented, highlighting potential prospects for the future. PMID:24287543

  15. Quality control and performance evaluation of k0-based neutron activation analysis at the Portuguese research reactor

    NASA Astrophysics Data System (ADS)

    Dung, H. M.; Freitas, M. C.; Blaauw, M.; Almeida, S. M.; Dionisio, I.; Canha, N. H.

    2010-10-01

    The quality control (QC) and performance evaluation for the k0-based neutron activation analysis ( k0-NAA) at the Portuguese research reactor (RPI) has been developed with the intention of using the method to meet the demands of trace element analysis for the applications in environmental, epidemiological and nutritional studies amongst others. The QC and performance evaluation include the following aspects: (1) estimation of the overall/combined standard uncertainty from the primary uncertainty sources; (2) validation of the method using a synthetic multi-element standard (SMELS); and (3) analysis of the certified reference materials from the National Institute of Standards and Technology (USA): NIST-SRM-1633a and NIST-SRM-1648 and the reference material from the International Atomic Energy Agency: IAEA-RM-336, for the purpose of controlling the overall accuracy and precision of the analytical results. The obtained results revealed that the k0-NAA method established at the RPI was fit for the purpose. The overall/combined standard uncertainty was estimated for elements of interest in the intended applications. The laboratory's analytical results as compared to the assigned values with the bias were less than 12% for most elements, except for a few elements which biased within 13-18%. The u-score values for most elements were less than |1.64|, except for Co, La and Ti within |1.64|-|1.96| and Sc, Cr, K and Sb within |1.96|-|2.58|. The NIST-1633a was also analyzed over 14 months for the purpose of evaluating the reproducibility of the method. The quality factors of k0-NAA established at RPI were evaluated, proving that the method meets the requirements of trace element analysis, which is also considering the method's performance for which the k0-NAA affords a specific, rapid and convenient capability for the intended applications.

  16. Application of hazard analysis and critical control point methodology and risk-based grading to consumer food safety surveys.

    PubMed

    Røssvoll, Elin Halbach; Ueland, Øydis; Hagtvedt, Therese; Jacobsen, Eivind; Lavik, Randi; Langsrud, Solveig

    2012-09-01

    Traditionally, consumer food safety survey responses have been classified as either "right" or "wrong" and food handling practices that are associated with high risk of infection have been treated in the same way as practices with lower risks. In this study, a risk-based method for consumer food safety surveys has been developed, and HACCP (hazard analysis and critical control point) methodology was used for selecting relevant questions. We conducted a nationally representative Web-based survey (n = 2,008), and to fit the self-reported answers we adjusted a risk-based grading system originally developed for observational studies. The results of the survey were analyzed both with the traditional "right" and "wrong" classification and with the risk-based grading system. The results using the two methods were very different. Only 5 of the 10 most frequent food handling violations were among the 10 practices associated with the highest risk. These 10 practices dealt with different aspects of heat treatment (lacking or insufficient), whereas the majority of the most frequent violations involved storing food at room temperature for too long. Use of the risk-based grading system for survey responses gave a more realistic picture of risks associated with domestic food handling practices. The method highlighted important violations and minor errors, which are performed by most people and are not associated with significant risk. Surveys built on a HACCP-based approach with risk-based grading will contribute to a better understanding of domestic food handling practices and will be of great value for targeted information and educational activities.

  17. Controls on Nitrogen Fluxes from Agricultural Fields: Differing Conclusions Based on Choice of Sensitivity Analysis Method

    NASA Astrophysics Data System (ADS)

    Ahrens, T.; Matson, P.; Lobell, D.

    2006-12-01

    Sensitivity analyses (SA) of biogeochemical and agricultural models are often used to identify the importance of input variables for variance in model outputs, such as crop yield or nitrate leaching. Identification of these factors can aid in prioritizing efforts in research or decision support. Many types of sensitivity analyses are available, ranging from simple One-At-A-Time (OAT) screening exercises to more complex local and global variance-based methods (see Saltelli et al 2004). The purpose of this study was to determine the influence of the type of SA on factor prioritization in the Yaqui Valley, Mexico using the Water and Nitrogen Management Model (WNMM; Chen et al 2005). WNMM, a coupled plant-growth - biogeochemistry simulation model, was calibrated to reproduce crop growth, soil moisture, and gaseous N emission dynamics in experimental plots of irrigated wheat in the Yaqui Valley, Mexico from 1994-1997. Three types of SA were carried out using 16 input variables, including parameters related to weather, soil properties and crop management. Methods used for SA were local OAT, Monte Carlo (MC), and a global variance-based method (orthogonal input; OI). Results of the SA were based on typical interpretations used for each test: maximum absolute ratio of variation (MAROV) for OAT analyses; first- and second-order regressions for MC analyses; and a total effects index for OI. The three most important factors identified by MC and OI methods were generally in agreement, although the order of importance was not always consistent and there was little agreement for variables of less importance. OAT over-estimated the importance of two factors (planting date and pH) for many outputs. The biggest differences between the OAT results and those from MC and OI were likely due to the inability of OAT methods to account for non-linearity (eg. pH and ammonia volatilization), interactions among variables (eg. pH and timing of fertilization) and an over-reliance on baseline

  18. Analysis of the horizontal structure of a measurement and control geodetic network based on entropy

    NASA Astrophysics Data System (ADS)

    Mrówczyńska, Maria

    2013-06-01

    The paper attempts to determine an optimum structure of a directional measurement and control network intended for investigating horizontal displacements. For this purpose it uses the notion of entropy as a logarithmical measure of probability of the state of a particular observation system. An optimum number of observations results from the difference of the entropy of the vector of parameters ΔHX̂ (x)corresponding to one extra observation. An increment of entropy interpreted as an increment of the amount of information about the state of the system determines the adoption or rejection of another extra observation to be carried out. W pracy podjęto próbę określenia optymalnej struktury sieci kierunkowej pomiarowo-kontrolnej przeznaczonej do badań przemieszczeń poziomych. W tym celu wykorzystano pojęcie entropii jako logarytmicznej miary prawdopodobieństwa stanu określonego układu obserwacyjnego. Optymalna liczba realizowanych obserwacji wynika z różnicy entropii wektora parametrów ΔHX̂ (x) odpowiadającej jednej obserwacji nadliczbowej. Przyrost entropii interpretowany jako przyrost objętości informacji na temat stanu układu decyduje o przyjęciu względnie odrzuceniu do realizacji kolejnej obserwacji nadliczbowej.

  19. Phylogeographic study of brown trout from Serbia, based on mitochondrial DNA control region analysis

    PubMed Central

    Marić, Saša; Sušnik, Simona; Simonović, Predrag; Snoj, Aleš

    2006-01-01

    In order to illuminate the phylogeography of brown trout (Salmo trutta) populations in the Balkan state of Serbia, the 561 bp 5'-end of mtDNA control region of 101 individuals originating from upland tributaries of the Danubian, Aegean and Adriatic drainages were sequenced and compared to corresponding brown trout sequences obtained in previous studies. Among 15 haplotypes found, 14 were considered native, representing the Danubian and Adriatic lineages of the brown trout, while one haplotype (ATcs1), found only in two individuals originating from two stocked rivers, corresponded to the Atlantic lineage and was considered introduced. Native haplotypes exhibited a strong geographic pattern of distribution: the Danubian haplotypes were strictly confined to the Danubian drainage, while the Adriatic haplotypes dominated in the Aegean and Adriatic drainages; most of the total molecular variance (69%) was attributed to differences among the drainages. Phylogenetic reconstruction, supplemented with seven haplotypes newly described in this study, suggested a sister position of the Atlantic-Danubian and Adriatic-Mediterranean-marmoratus ("southern") phylogenetic group, and pointed to the existence of a distinct clade, detected within the "southern" group. The data obtained confirmed our expectation of the existence of high genetic diversity in Balkan trout populations, and we recommend more widespread surveys covering trout stocks from the region. PMID:16790230

  20. Estimating mean QALYs in trial-based cost-effectiveness analysis: the importance of controlling for baseline utility.

    PubMed

    Manca, Andrea; Hawkins, Neil; Sculpher, Mark J

    2005-05-01

    In trial-based cost-effectiveness analysis baseline mean utility values are invariably imbalanced between treatment arms. A patient's baseline utility is likely to be highly correlated with their quality-adjusted life-years (QALYs) over the follow-up period, not least because it typically contributes to the QALY calculation. Therefore, imbalance in baseline utility needs to be accounted for in the estimation of mean differential QALYs, and failure to control for this imbalance can result in a misleading incremental cost-effectiveness ratio. This paper discusses the approaches that have been used in the cost-effectiveness literature to estimate absolute and differential mean QALYs alongside randomised trials, and illustrates the implications of baseline mean utility imbalance for QALY calculation. Using data from a recently conducted trial-based cost-effectiveness study and a micro-simulation exercise, the relative performance of alternative estimators is compared, showing that widely used methods to calculate differential QALYs provide incorrect results in the presence of baseline mean utility imbalance regardless of whether these differences are formally statistically significant. It is demonstrated that multiple regression methods can be usefully applied to generate appropriate estimates of differential mean QALYs and an associated measure of sampling variability, while controlling for differences in baseline mean utility between treatment arms in the trial. Copyright 2004 John Wiley & Sons, Ltd

  1. A randomised controlled trial and mediation analysis of the 'Healthy Habits', telephone-based dietary intervention for preschool children.

    PubMed

    Fletcher, Amanda; Wolfenden, Luke; Wyse, Rebecca; Bowman, Jenny; McElduff, Patrick; Duncan, Sarah

    2013-04-08

    Consumption of non-core foods in childhood is associated with excessive weight gain in childhood. Parents play a vital role in establishing healthy diet behaviours in young children. The aim of this study was to assess the effectiveness of a telephone-based intervention in reducing child consumption of non-core foods, and to examine parent and home food environment mediators of change in child consumption. The 'Healthy Habits' trial utilised a clustered randomised controlled design. Parents were recruited from 30 preschools (N=394 participants, mean age 35.2±5.6 years). Parents randomized to the intervention group received four telephone contacts and print materials. Parents allocated to the control condition receive generic print materials only. Non-core food consumption was assessed using a validated child dietary questionnaire at baseline, 2 and 6 months post recruitment in 2010. The intervention was effective in reducing child consumption of non-core foods at 2 months (intention to treat analysis: z=-2.83, p<.01), however this effect was not maintained at 6 months. Structural equation modelling using 2 month data indicated that child access to non-core foods in the home and child feeding strategies mediated the effect of the intervention. The telephone-based intervention shows promise in improving short term dietary behaviour in preschool age children, however further development is needed to sustain the effect in the long-term. Australian Clinical Trials Registry: ACTRN12609000820202.

  2. Improving mesocosm data analysis through individual-based modelling of control population dynamics: a case study with mosquitofish (Gambusia holbrooki).

    PubMed

    Beaudouin, Rémy; Ginot, Vincent; Monod, Gilles

    2012-01-01

    Experimental ecosystems such as mesocosms have been developed to improve the ecological relevance of ecotoxicity test. However, in mesocosm studies, the number of replicates is limited by practical and financial constraints. In addition, high levels of biological organization are characterized by a high variability of descriptive variables. This variability and the poor number of replicates have been recognized as a major drawback for detecting significant effects of chemicals in mesocosm studies. In this context, a tool able to predict precisely control mesocosms outputs, to which endpoints in mesocosms exposed to chemicals could be compared should constitute a substantial improvement. We evaluated here a solution which consists in stochastic modelling of the control fish populations to assess the probabilistic distributions of population endpoints. An individual-based approach was selected, because it generates realistic fish length distributions and accounts for both individual and environmental sources of variability. This strategy was applied to mosquitofish (Gambusia holbrooki) populations monitored in lentic mesocosms. We chose the number of founders as a so-called "stressor" because subsequent consequences at the population level could be expected. Using this strategy, we were able to detect more significant and biologically relevant perturbations than using classical methods. We conclude that designing an individual-based model is very promising for improving mesocosm data analysis. This methodology is currently being applied to ecotoxicological issues.

  3. Deciphering the genetic control of fruit texture in apple by multiple family-based analysis and genome-wide association

    PubMed Central

    Di Guardo, Mario; Bink, Marco C.A.M.; Guerra, Walter; Letschka, Thomas; Lozano, Lidia; Busatto, Nicola; Poles, Lara; Tadiello, Alice; Bianco, Luca; Visser, Richard G.F.; van de Weg, Eric

    2017-01-01

    Abstract Fruit texture is a complex feature composed of mechanical and acoustic properties relying on the modifications occurring in the cell wall throughout fruit development and ripening. Apple is characterized by a large variation in fruit texture behavior that directly impacts both the consumer’s appreciation and post-harvest performance. To decipher the genetic control of fruit texture comprehensively, two complementing quantitative trait locus (QTL) mapping approaches were employed. The first was represented by a pedigree-based analysis (PBA) carried out on six full-sib pedigreed families, while the second was a genome-wide association study (GWAS) performed on a collection of 233 apple accessions. Both plant materials were genotyped with a 20K single nucleotide polymorphism (SNP) array and phenotyped with a sophisticated high-resolution texture analyzer. The overall QTL results indicated the fundamental role of chromosome 10 in controlling the mechanical properties, while chromosomes 2 and 14 were more associated with the acoustic response. The latter QTL, moreover, showed a consistent relationship between the QTL-estimated genotypes and the acoustic performance assessed among seedlings. The in silico annotation of these intervals revealed interesting candidate genes potentially involved in fruit texture regulation, as suggested by the gene expression profile. The joint integration of these approaches sheds light on the specific control of fruit texture, enabling important genetic information to assist in the selection of valuable fruit quality apple varieties. PMID:28338805

  4. The effects of repeated-sprint training on field-based fitness measures: a meta-analysis of controlled and non-controlled trials.

    PubMed

    Taylor, Jonathan; Macpherson, Tom; Spears, Iain; Weston, Matthew

    2015-06-01

    Repeated-sprint training appears to be an efficient and practical means for the simultaneous development of different components of fitness relevant to team sports. Our objective was to systematically review the literature and meta-analyse the effect of repeated-sprint training on a selection of field-based measures of athletic performance, i.e. counter-movement jump, 10 m sprint, 20 m sprint, 30 m sprint, repeated-sprint ability and high-intensity intermittent running performance. The SPORTDiscus, PubMed, MEDLINE and Web of Science databases were searched for original research articles. Search terms included 'repeated-sprint training', 'sprint training', 'aerobic endurance', 'repeated-sprint ability', 'counter-movement jump' and 'sprint performance'. Inclusion criteria included intervention consisting of a series of ≤10 s sprints with ≤60 s recovery; trained participants; intervention duration of 2-12 weeks; field-based fitness measures; running- or cycling-based intervention; published up to, and including, February 2014. Our final dataset included six trials for counter-movement jump (two controlled trials), eight trials for 10 m sprint, four trials for 20 m sprint (three controlled trials), two trials for 30 m sprint, eight trials for repeated-sprint ability and three trials for high-intensity intermittent running performance. Analyses were conducted using comprehensive meta-analysis software. Uncertainty in the meta-analysed effect of repeated-sprint training was expressed as 95% confidence limits (CL), along with the probability that the true value of the effect was trivial, beneficial or harmful. Magnitude-based inferences were based on standardised thresholds for small, moderate and large changes of 0.2, 0.6 and 1.2 standard deviations, respectively. Repeated-sprint training had a likely small beneficial effect in non-controlled counter-movement jump trials (effect size 0.33; 95% CL ±0.30), with a possibly moderate beneficial effect in controlled

  5. Effects of exercise-based interventions on postpartum depression: A meta-analysis of randomized controlled trials.

    PubMed

    Poyatos-León, Raquel; García-Hermoso, Antonio; Sanabria-Martínez, Gema; Álvarez-Bueno, Celia; Cavero-Redondo, Iván; Martínez-Vizcaíno, Vicente

    2017-09-01

    There is inconsistent evidence about the effect of physical activity on the prevention and treatment of depression during the postnatal period. The aim of this meta-analysis was to determine the effect of physical activity interventions during pregnancy and the postpartum period for controlling postpartum depressive symptoms. We systematically searched Cochrane Library Plus, Science Direct, EMBASE, CINAHL, PubMed, Web of Science, and Scopus, from January 1990 to May 2016, for randomized or nonrandomized controlled trials addressing the effect of physical activity on postpartum depression. The inverse variance-weighted method was used to compute pooled estimates of effect size and respective 95% confidence intervals (95% CI) for physical activity intervention on postpartum depression. Subgroup analyses were performed comparing women with and without postpartum depressive symptoms according to specific scales measuring this construct. Meta-regression and sensitivity analysis were computed to evaluate heterogeneity. Twelve studies were included in the meta-analysis. Effect size for the relationship between physical activity interventions during pregnancy and the postpartum period on postpartum depressive symptoms was 0.41 (95% CI 0.28-0.54). Heterogeneity was I(2)  = 33.1% (P = .117). When subgroup analyses were done, pooled effect sizes were 0.67 (95% CI 0.44-0.90) for mothers who met postpartum depressive symptoms criteria at baseline based on specific scales, and 0.29 (95% CI 0.14-0.45) for mothers who did not meet those depressive symptoms criteria at baseline. Physical exercise during pregnancy and the postpartum period is a safe strategy to achieve better psychological well-being and to reduce postpartum depressive symptoms. © 2017 Wiley Periodicals, Inc.

  6. The efficacy of smartphone‐based mental health interventions for depressive symptoms: a meta‐analysis of randomized controlled trials

    PubMed Central

    Firth, Joseph; Torous, John; Nicholas, Jennifer; Carney, Rebekah; Pratap, Abhishek; Rosenbaum, Simon; Sarris, Jerome

    2017-01-01

    The rapid advances and adoption of smartphone technology presents a novel opportunity for delivering mental health interventions on a population scale. Despite multi‐sector investment along with wide‐scale advertising and availability to the general population, the evidence supporting the use of smartphone apps in the treatment of depression has not been empirically evaluated. Thus, we conducted the first meta‐analysis of smartphone apps for depressive symptoms. An electronic database search in May 2017 identified 18 eligible randomized controlled trials of 22 smartphone apps, with outcome data from 3,414 participants. Depressive symptoms were reduced significantly more from smartphone apps than control conditions (g=0.38, 95% CI: 0.24‐0.52, p<0.001), with no evidence of publication bias. Smartphone interventions had a moderate positive effect in comparison to inactive controls (g=0.56, 95% CI: 0.38‐0.74), but only a small effect in comparison to active control conditions (g=0.22, 95% CI: 0.10‐0.33). Effects from smartphone‐only interventions were greater than from interventions which incorporated other human/computerized aspects along the smartphone component, although the difference was not statistically significant. The studies of cognitive training apps had a significantly smaller effect size on depression outcomes (p=0.004) than those of apps focusing on mental health. The use of mood monitoring softwares, or interventions based on cognitive behavioral therapy, or apps incorporating aspects of mindfulness training, did not affect significantly study effect sizes. Overall, these results indicate that smartphone devices are a promising self‐management tool for depression. Future research should aim to distil which aspects of these technologies produce beneficial effects, and for which populations. PMID:28941113

  7. Internet-based cognitive–behavioural therapy for insomnia (ICBT-i): a meta-analysis of randomised controlled trials

    PubMed Central

    Ye, Yuan-yuan; Chen, Ni-ka; Chen, Jia; Liu, Juan; Lin, Ling; Liu, Ya-zhen; Lang, Ying; Li, Xun-jun; Yang, Xin-ju; Jiang, Xiao-jiang

    2016-01-01

    Objective To evaluate the effectiveness of internet-based cognitive–behavioural therapy for insomnia (ICBT-i) in adults. Design A meta-analysis of ICBT-i. Data sources Systematic searches of randomised controlled trials of ICBT-i were performed in the PubMed, EMBASE, PsycINFO and Cochrane Library databases up to 19 June 2016. Review method 2 reviewers independently performed study selection, quality assessment and data extraction. Outcomes of interest included sleep onset latency (SOL), total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), number of nocturnal awakenings (NWAK), and Insomnia Severity Index (ISI). RevMan 5.2 and Stata 13.0 meta-analysis software were used to perform statistical analysis. Results 14 records for 15 studies (1013 experimental group participants, 591 waiting list group participants) were included. The meta-analysis indicated that, at the post-test time point, SOL decreased by 18.41 min (95% CI 13.60 to 23.21), TST increased by 22.30 min (95% CI 16.38 to 28.23), SE increased by 9.58% (95% CI 7.30% to 11.85%), WASO decreased by 22.31 min (95% CI 13.50 to 31.11), NWAK decreased by 0.52 (95% CI 0.28 to 0.76), and ISI decreased by 5.88 points (95% CI 4.29 to 7.46). Additionally SOL, TST, SE, and WASO exhibited statistically significant improvements at follow-up versus before treatment. Conclusions ICBT-i is an effective treatment for adults with insomnia. This conclusion should be verified in further studies. PMID:27903557

  8. Coupling effect and control strategies of the maglev dual-stage inertially stabilization system based on frequency-domain analysis.

    PubMed

    Lin, Zhuchong; Liu, Kun; Zhang, Li; Zeng, Delin

    2016-09-01

    Maglev dual-stage inertially stabilization (MDIS) system is a newly proposed system which combines a conventional two-axis gimbal assembly and a 5-DOF (degree of freedom) magnetic bearing with vernier tilting capacity to perform dual-stage stabilization for the LOS of the suspended optical instrument. Compared with traditional dual-stage system, maglev dual-stage system exhibits different characteristics due to the negative position stiffness of the magnetic forces, which introduces additional coupling in the dual stage control system. In this paper, the coupling effect on the system performance is addressed based on frequency-domain analysis, including disturbance rejection, fine stage saturation and coarse stage structural resonance suppression. The difference between various control strategies is also discussed, including pile-up(PU), stabilize-follow (SF) and stabilize-compensate (SC). A number of principles for the design of a maglev dual stage system are proposed. A general process is also suggested, which leads to a cost-effective design striking a balance between high performance and complexity. At last, a simulation example is presented to illustrate the arguments in the paper.

  9. Network-based multiple sclerosis pathway analysis with GWAS data from 15,000 cases and 30,000 controls.

    PubMed

    2013-06-06

    Multiple sclerosis (MS) is an inflammatory CNS disease with a substantial genetic component, originally mapped to only the human leukocyte antigen (HLA) region. In the last 5 years, a total of seven genome-wide association studies and one meta-analysis successfully identified 57 non-HLA susceptibility loci. Here, we merged nominal statistical evidence of association and physical evidence of interaction to conduct a protein-interaction-network-based pathway analysis (PINBPA) on two large genetic MS studies comprising a total of 15,317 cases and 29,529 controls. The distribution of nominally significant loci at the gene level matched the patterns of extended linkage disequilibrium in regions of interest. We found that products of genome-wide significantly associated genes are more likely to interact physically and belong to the same or related pathways. We next searched for subnetworks (modules) of genes (and their encoded proteins) enriched with nominally associated loci within each study and identified those modules in common between the two studies. We demonstrate that these modules are more likely to contain genes with bona fide susceptibility variants and, in addition, identify several high-confidence candidates (including BCL10, CD48, REL, TRAF3, and TEC). PINBPA is a powerful approach to gaining further insights into the biology of associated genes and to prioritizing candidates for subsequent genetic studies of complex traits.

  10. Network analysis of cattle movements in Uruguay: Quantifying heterogeneity for risk-based disease surveillance and control.

    PubMed

    VanderWaal, Kimberly L; Picasso, Catalina; Enns, Eva A; Craft, Meggan E; Alvarez, Julio; Fernandez, Federico; Gil, Andres; Perez, Andres; Wells, Scott

    2016-01-01

    Movement of livestock between premises is one of the foremost factors contributing to the spread of infectious diseases of livestock. In part to address this issue, the origin and destination for all cattle movements in Uruguay are registered by law. This information has great potential to be used in assessing the risk of disease spread in the Uruguayan cattle population. Here, we analyze cattle movements from 2008 to 2013 using network analysis in order to understand the flows of animals in the Uruguayan cattle industry and to identify targets for surveillance and control measures. Cattle movements were represented as seasonal and annual networks in which farms represented nodes and nodes were linked based on the frequency and quantity of cattle moved. At the farm level, the distribution of the number of unique farms each farm is connected to through outgoing and incoming movements, as well as the number of animals moved, was highly right-skewed; the majority of farms had few to no contacts, whereas the 10% most highly connected farms accounted for 72-83% of animals moved annually. This extreme level of heterogeneity in movement patterns indicates that some farms may be disproportionately important for pathogen spread. Different production types exhibited characteristic patterns of farm-level connectivity, with some types, such a dairies, showing consistently higher levels of centrality. In addition, the observed networks were characterized by lower levels of connectivity and higher levels of heterogeneity than random networks of the same size and density, both of which have major implications for disease dynamics and control strategies. This represents the first in-depth analysis of farm-level livestock movements within South America, and highlights the importance of collecting livestock movement data in order to understand the vulnerability of livestock trade networks to invasion by infectious diseases.

  11. Analysis of pilot control strategy

    NASA Technical Reports Server (NTRS)

    Heffley, R. K.; Hanson, G. D.; Jewell, W. F.; Clement, W. F.

    1983-01-01

    Methods for nonintrusive identification of pilot control strategy and task execution dynamics are presented along with examples based on flight data. The specific analysis technique is Nonintrusive Parameter Identification Procedure (NIPIP), which is described in a companion user's guide (NASA CR-170398). Quantification of pilot control strategy and task execution dynamics is discussed in general terms followed by a more detailed description of how NIPIP can be applied. The examples are based on flight data obtained from the NASA F-8 digital fly by wire airplane. These examples involve various piloting tasks and control axes as well as a demonstration of how the dynamics of the aircraft itself are identified using NIPIP. Application of NIPIP to the AFTI/F-16 flight test program is discussed. Recommendations are made for flight test applications in general and refinement of NIPIP to include interactive computer graphics.

  12. Long-term Outcomes After Stepping Down Asthma Controller Medications: A Claims-Based, Time-to-Event Analysis.

    PubMed

    Rank, Matthew A; Johnson, Ryan; Branda, Megan; Herrin, Jeph; van Houten, Holly; Gionfriddo, Michael R; Shah, Nilay D

    2015-09-01

    Long-term outcomes after stepping down asthma medications are not well described. This study was a retrospective time-to-event analysis of individuals diagnosed with asthma who stepped down their asthma controller medications using a US claims database spanning 2000 to 2012. Four-month intervals were established and a step-down event was defined by a ≥ 50% decrease in days-supplied of controller medications from one interval to the next; this definition is inclusive of step-down that occurred without health-care provider guidance or as a consequence of a medication adherence lapse. Asthma stability in the period prior to step-down was defined by not having an asthma exacerbation (inpatient visit, ED visit, or dispensing of a systemic corticosteroid linked to an asthma visit) and having fewer than two rescue inhaler claims in a 4-month period. The primary outcome in the period following step-down was time-to-first asthma exacerbation. Thirty-two percent of the 26,292 included individuals had an asthma exacerbation in the 24-month period following step-down of asthma controller medication, though only 7% had an ED visit or hospitalization for asthma. The length of asthma stability prior to stepping down asthma medication was strongly associated with the risk of an asthma exacerbation in the subsequent 24-month period: < 4 months' stability, 44%; 4 to 7 months, 34%; 8 to 11 months, 30%; and ≥ 12 months, 21% (P < .001). In a large, claims-based, real-world study setting, 32% of individuals have an asthma exacerbation in the 2 years following a step-down event.

  13. WE-G-BRA-06: Application of Systems and Control Theory-Based Hazard Analysis to Radiotherapy

    SciTech Connect

    Pawlicki, T; Samost, A; Leveson, N

    2015-06-15

    Purpose: The process of delivering radiation occurs in a complex socio-technical system heavily reliant on human operators. Furthermore, both humans and software are notoriously challenging to account for in traditional hazard analysis models. High reliability industries such as aviation have approached this problem through using hazard analysis techniques grounded in systems and control theory. The purpose of this work is to apply the Systems Theoretic Accident Model Processes (STAMP) hazard model to radiotherapy. In particular, the System-Theoretic Process Analysis (STPA) approach is used to perform a hazard analysis of a proposed on-line adaptive cranial radiosurgery procedure that omits the CT Simulation step and uses only CBCT for planning, localization, and treatment. Methods: The STPA procedure first requires the definition of high-level accidents and hazards leading to those accidents. From there, hierarchical control structures were created followed by the identification and description of control actions for each control structure. Utilizing these control structures, unsafe states of each control action were created. Scenarios contributing to unsafe control action states were then identified and translated into system requirements to constrain process behavior within safe boundaries. Results: Ten control structures were created for this new CBCT-only process which covered the areas of hospital and department management, treatment design and delivery, and vendor service. Twenty three control actions were identified that contributed to over 80 unsafe states of those control actions resulting in over 220 failure scenarios. Conclusion: The interaction of people, hardware, and software are highlighted through the STPA approach. STPA provides a hierarchical model for understanding the role of management decisions in impacting system safety so that a process design requirement can be traced back to the hazard and accident that it is intended to mitigate. Varian

  14. Network meta-analysis of randomized controlled trials: efficacy and safety of UDCA-based therapies in primary biliary cirrhosis.

    PubMed

    Zhu, Gui-Qi; Shi, Ke-Qing; Huang, Sha; Huang, Gui-Qian; Lin, Yi-Qian; Zhou, Zhi-Rui; Braddock, Martin; Chen, Yong-Ping; Zheng, Ming-Hua

    2015-03-01

    Major ursodeoxycholic acid (UDCA)-based therapies for primary biliary cirrhosis (PBC) include UDCA only, or combined with either methotrexate (MTX), corticosteroids (COT), colchicine (COC), or bezafibrate (BEF). As the optimum treatment regimen is unclear and warrants exploration, we aimed to compare these therapies in terms of patient mortality or liver transplantation (MOLT) and adverse events (AE).PubMed, the Cochrane Library, and Scopus were searched for randomized controlled trials up to August 31, 2014. We estimated the hazard ratios (HRs) for MOLT and odds ratios (ORs) for AE. A sensitivity analysis based on the dose of UDCA was also executed.Thirty-one eligible articles were included. Compared with COT plus UDCA, UDCA (HR 0.38, 95% confidence interval [CI] 0.09-1.39), BEF plus UDCA (HR 0.29, 95% CI 0.02-4.83), COC plus UDCA (HR 0.39, 95% CI 0.07-2.25), MTX plus UDCA (HR 0.28, 95% CI 0.05-1.63), or OBS (HR 0.49, 95% CI 0.11-2.01) all provided an increased risk of MOLT. With respect to drug AE profile, although not differing appreciably, BEF plus UDCA was associated with more AEs compared with UDCA (OR 3.16, 95% CI 0.59-20.67), COT plus UDCA (OR 2.27, 95% CI 0.15-33.36), COC plus UDCA (OR 1.00, 95% CI 0.09-12.16), MTX plus UDCA (OR 2.03, 95% CI 0.23-17.82), or OBS (OR 3.00, 95% CI 0.53-20.75). The results of sensitivity analyses were highly consistent with previous analyses.COT plus UDCA was the optimal UDCA-based regimen for both MOLT and AEs. BEF plus UDCA was most likely to cause AEs, whereas monotherapy with UDCA and coadministriation of COT plus UDCA appeared to be associated with the fewest AEs for PBC treatment.

  15. Stability analysis and H(infinity) controller design of discrete-time fuzzy large-scale systems based on piecewise Lyapunov functions.

    PubMed

    Zhang, Hongbin; Feng, Gang

    2008-10-01

    This paper is concerned with stability analysis and H(infinity) decentralized control of discrete-time fuzzy large-scale systems based on piecewise Lyapunov functions. The fuzzy large-scale systems consist of J interconnected discrete-time Takagi-Sugeno (T-S) fuzzy subsystems, and the stability analysis is based on Lyapunov functions that are piecewise quadratic. It is shown that the stability of the discrete-time fuzzy large-scale systems can be established if a piecewise quadratic Lyapunov function can be constructed, and moreover, the function can be obtained by solving a set of linear matrix inequalities (LMIs) that are numerically feasible. The H(infinity) controllers are also designed by solving a set of LMIs based on these powerful piecewise quadratic Lyapunov functions. It is demonstrated via numerical examples that the stability and controller synthesis results based on the piecewise quadratic Lyapunov functions are less conservative than those based on the common quadratic Lyapunov functions.

  16. Analysis of axial-induction-based wind plant control using an engineering and a high-order wind plant model

    SciTech Connect

    Annoni, Jennifer; Gebraad, Pieter M. O.; Scholbrock, Andrew K.; Fleming, Paul A.; Wingerden, Jan-Willem van

    2015-08-14

    Wind turbines are typically operated to maximize their performance without considering the impact of wake effects on nearby turbines. Wind plant control concepts aim to increase overall wind plant performance by coordinating the operation of the turbines. This paper focuses on axial-induction-based wind plant control techniques, in which the generator torque or blade pitch degrees of freedom of the wind turbines are adjusted. The paper addresses discrepancies between a high-order wind plant model and an engineering wind plant model. Changes in the engineering model are proposed to better capture the effects of axial-induction-based control shown in the high-order model.

  17. Analysis of Fast-Scale Bifurcation in Peak Current Controlled Buck-Boost Inverter Based on Unified Averaged Model

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Dong, Shuai; Guan, Weimin; Liu, Ye

    In this paper, a unified averaged modeling method is proposed to investigate the fast-scale period-doubling bifurcation of a full-bridge integrated buck-boost inverter with peak current control. In order to increase the resolution of the conventional classic averaged model to half the switching frequency, sample-and-hold effect of inductor current is absorbed into the averaged model, i.e. the proposed unified averaged model can capture the high-frequency dynamical characteristics of the buck-boost inverter, which is both an extension and a modification of conventional averaged model. Based on the unified mode, fast-scale bifurcation is identified, and the corresponding bifurcation point is predicted with the help of the locus movement of all the poles, and their underlying mechanisms are revealed. Detailed analysis shows that the occurrence of high-frequency oscillation means fast-scale bifurcation, while the occurrence of low-frequency oscillation leads to slow-scale bifurcation. Finally, it is demonstrated that the unified averaged model can provide not only a general method to investigate both the slow- and fast-scale bifurcations in a unified framework but also a quite straightforward design-oriented method which can be directly applicable.

  18. Effectiveness of school-based preventive interventions on adolescent alcohol use: a meta-analysis of randomized controlled trials.

    PubMed

    Strøm, Henriette Kyrrestad; Adolfsen, Frode; Fossum, Sturla; Kaiser, Sabine; Martinussen, Monica

    2014-12-13

    Preventive interventions for adolescents are an important priority within school systems. Several interventions have been developed, but the effectiveness of such interventions varies considerably between studies. The purpose of this study was to assess the effectiveness of universal school-based prevention programs on alcohol use among adolescents by using meta-analytic techniques. A systematic literature search in the databases, PubMed (Medline), PsycINFO (Ovid), EMBASE (Ovid) and WEB of Science (ISI) was conducted to search for empirical articles published in the period January 1990 to August 2014. In total, 28 randomized controlled studies with 39,289 participants at baseline were included. Of these 28 articles, 12 studies (N = 16279) reported continuous outcomes (frequency of alcohol use and quantity of alcohol use), and 16 studies (N = 23010) reported categorical data (proportion of students who drank alcohol). The results of the random effects analyses showed that the overall effect size among studies reporting continuous outcomes was small and demonstrated a favorable effect from the preventive interventions (Hedges' g = 0.22, p < .01). The effect size among studies reporting categorical outcomes was not significant (OR = 0.94, p = .25). The level of heterogeneity between studies was found to be significant in most analyses. Moderator analyses conducted to explore the heterogeneity showed neither significant difference between the different school levels (junior high schools and high schools), nor between the varied program intensities (low, medium and high intensity programs). The meta-regression analyses examining continuous moderators showed no significant effects for age or gender. The findings from this meta-analysis showed that, overall, the effects of school-based preventive alcohol interventions on adolescent alcohol use were small but positive among studies reporting the continuous measures, whereas no effect was found among studies

  19. Seizures in patients with Alzheimer's disease or vascular dementia: a population-based nested case-control analysis.

    PubMed

    Imfeld, Patrick; Bodmer, Michael; Schuerch, Markus; Jick, Susan S; Meier, Christoph R

    2013-04-01

    Patients with Alzheimer's disease (AD) have an increased risk of developing seizures or epilepsy. Little is known about the role of risk factors and about the risk of developing seizures/epilepsy in patients with vascular dementia (VD). The aim of this study was to assess incidence rates (IRs) of seizures/epilepsy in patients with AD, VD, or without dementia, and to identify potential risk factors of seizures or epilepsy. We conducted a follow-up study with a nested case-control analysis using the United Kingdom-based General Practice Research Database (GPRD). We identified patients aged ≥65 years with an incident diagnosis of AD or VD between 1998 and 2008 and a matched comparison group of dementia-free patients. Conditional logistic regression was used to estimate the odds ratio (OR) with a 95% confidence interval (CI) of developing seizures/epilepsy in patients with AD or VD, stratified by age at onset and duration of dementia as well as by use of antidementia drugs. Among 7,086 cases with AD, 4,438 with VD, and 11,524 matched dementia-free patients, we identified 180 cases with an incident diagnosis of seizures/epilepsy. The IRs of epilepsy/seizures for patients with AD or VD were 5.6/1,000 person-years (py) (95% CI 4.6-6.9) and 7.5/1,000 py (95% CI 5.7-9.7), respectively, and 0.8/1,000 py (95% CI 0.6-1.1) in the dementia-free group. In the nested case-control analysis, patients with longer standing (≥3 years) AD had a slightly higher risk of developing seizures or epilepsy than those with a shorter disease duration, whereas in patients with VD the contrary was observed. Seizures or epilepsy were substantially more common in patients with AD and VD than in dementia-free patients. The role of disease duration as a risk factor for seizures/epilepsy seems to differ between AD and VD. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

  20. INCA- INTERACTIVE CONTROLS ANALYSIS

    NASA Technical Reports Server (NTRS)

    Bauer, F. H.

    1994-01-01

    The Interactive Controls Analysis (INCA) program was developed to provide a user friendly environment for the design and analysis of linear control systems, primarily feedback control systems. INCA is designed for use with both small and large order systems. Using the interactive graphics capability, the INCA user can quickly plot a root locus, frequency response, or time response of either a continuous time system or a sampled data system. The system configuration and parameters can be easily changed, allowing the INCA user to design compensation networks and perform sensitivity analysis in a very convenient manner. A journal file capability is included. This stores an entire sequence of commands, generated during an INCA session into a file which can be accessed later. Also included in INCA are a context-sensitive help library, a screen editor, and plot windows. INCA is robust to VAX-specific overflow problems. The transfer function is the basic unit of INCA. Transfer functions are automatically saved and are available to the INCA user at any time. A powerful, user friendly transfer function manipulation and editing capability is built into the INCA program. The user can do all transfer function manipulations and plotting without leaving INCA, although provisions are made to input transfer functions from data files. By using a small set of commands, the user may compute and edit transfer functions, and then examine these functions by using the ROOT_LOCUS, FREQUENCY_RESPONSE, and TIME_RESPONSE capabilities. Basic input data, including gains, are handled as single-input single-output transfer functions. These functions can be developed using the function editor or by using FORTRAN- like arithmetic expressions. In addition to the arithmetic functions, special functions are available to 1) compute step, ramp, and sinusoid functions, 2) compute closed loop transfer functions, 3) convert from S plane to Z plane with optional advanced Z transform, and 4) convert from Z

  1. INCA- INTERACTIVE CONTROLS ANALYSIS

    NASA Technical Reports Server (NTRS)

    Bauer, F. H.

    1994-01-01

    The Interactive Controls Analysis (INCA) program was developed to provide a user friendly environment for the design and analysis of linear control systems, primarily feedback control systems. INCA is designed for use with both small and large order systems. Using the interactive graphics capability, the INCA user can quickly plot a root locus, frequency response, or time response of either a continuous time system or a sampled data system. The system configuration and parameters can be easily changed, allowing the INCA user to design compensation networks and perform sensitivity analysis in a very convenient manner. A journal file capability is included. This stores an entire sequence of commands, generated during an INCA session into a file which can be accessed later. Also included in INCA are a context-sensitive help library, a screen editor, and plot windows. INCA is robust to VAX-specific overflow problems. The transfer function is the basic unit of INCA. Transfer functions are automatically saved and are available to the INCA user at any time. A powerful, user friendly transfer function manipulation and editing capability is built into the INCA program. The user can do all transfer function manipulations and plotting without leaving INCA, although provisions are made to input transfer functions from data files. By using a small set of commands, the user may compute and edit transfer functions, and then examine these functions by using the ROOT_LOCUS, FREQUENCY_RESPONSE, and TIME_RESPONSE capabilities. Basic input data, including gains, are handled as single-input single-output transfer functions. These functions can be developed using the function editor or by using FORTRAN- like arithmetic expressions. In addition to the arithmetic functions, special functions are available to 1) compute step, ramp, and sinusoid functions, 2) compute closed loop transfer functions, 3) convert from S plane to Z plane with optional advanced Z transform, and 4) convert from Z

  2. Sevelamer Versus Calcium-Based Binders for Treatment of Hyperphosphatemia in CKD: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Patel, Leena; Bernard, Lisa M.

    2016-01-01

    Background and objectives People with CKD stages 3–5 and on dialysis (5D) have dramatically increased mortality, which has been associated with hyperphosphatemia in many studies. Oral phosphate binders are commonly prescribed to lower serum phosphate. We conducted an updated meta-analysis of the noncalcium–based binder (non-CBB) sevelamer versus CBBs in CKD stages 3–5D. Design, setting, participants, & measurements Randomized, controlled trials comparing sevelamer with CBBs were identified through MEDLINE and the Cochrane Central Register of Controlled Trials. Patient-level outcomes included all-cause mortality, cardiovascular events and mortality, hospitalization, and adverse effects. Intermediate outcomes included vascular calcification and bone changes. Biochemical outcomes included serum phosphate, calcium, parathyroid hormone, lipids, and hypercalcemia. We conducted and reported this review according to Cochrane guidelines. Results We included 25 studies to March 31, 2015 with 4770 participants (88% on hemodialysis). Patients receiving sevelamer had lower all–cause mortality (risk ratio [RR], 0.54; 95% confidence interval [95% CI], 0.32 to 0.93), no statistically significant difference in cardiovascular mortality (n=2712; RR, 0.33; 95% CI, 0.07 to 1.64), and an increase in combined gastrointestinal events of borderline statistical significance (n=384; RR, 1.42; 95% CI, 0.97 to 2.08). For biochemical outcomes, patients receiving sevelamer had lower total serum cholesterol (mean difference [MD], −20.2 mg/dl; 95% CI, −25.9 to −14.5 mg/dl), LDL-cholesterol (MD, −21.6 mg/dl; 95% CI, −27.9 to −15.4 mg/dl), and calcium (MD, −0.4 mg/dl; 95% CI, −0.6 to −0.2 mg/dl) and a reduced risk of hypercalcemia (RR, 0.30; 95% CI, 0.19 to 0.48). End of treatment intact parathyroid hormone was significantly higher for sevelamer (MD, 32.9 pg/ml; 95% CI, 0.1 to 65.7 pg/ml). Serum phosphate values showed no significant differences. Conclusions Patients with

  3. Performance Analysis of Extracted Rule-Base Multivariable Type-2 Self-Organizing Fuzzy Logic Controller Applied to Anesthesia

    PubMed Central

    Fan, Shou-Zen; Shieh, Jiann-Shing

    2014-01-01

    We compare type-1 and type-2 self-organizing fuzzy logic controller (SOFLC) using expert initialized and pretrained extracted rule-bases applied to automatic control of anaesthesia during surgery. We perform experimental simulations using a nonfixed patient model and signal noise to account for environmental and patient drug interaction uncertainties. The simulations evaluate the performance of the SOFLCs in their ability to control anesthetic delivery rates for maintaining desired physiological set points for muscle relaxation and blood pressure during a multistage surgical procedure. The performances of the SOFLCs are evaluated by measuring the steady state errors and control stabilities which indicate the accuracy and precision of control task. Two sets of comparisons based on using expert derived and extracted rule-bases are implemented as Wilcoxon signed-rank tests. Results indicate that type-2 SOFLCs outperform type-1 SOFLC while handling the various sources of uncertainties. SOFLCs using the extracted rules are also shown to outperform those using expert derived rules in terms of improved control stability. PMID:25587533

  4. Stability analysis of autonomous space systems in the presence of large disturbances: A Lyapunov-based constrained control strategy.

    PubMed

    Mazinan, A H

    2016-03-01

    The research addresses a Lyapunov-based constrained control strategy to deal with the autonomous space system in the presence of large disturbances. The aforementioned autonomous space system under control is first represented through a dynamics model and subsequently the proposed control strategy is fully investigated with a focus on the three-axis detumbling and the corresponding pointing mode control approaches. The three-axis detumbling mode control approach is designed to deal with the unwanted angular rates of the system to be zero, while the saturations of the actuators are taken into consideration. Moreover, the three-axis pointing mode control approach is designed in the similar state to deal with the rotational angles of the system to be desirable. The contribution of the research is mathematically made to propose a control law in connection with a new candidate of Lyapunov function to deal with the rotational angles and the related angular rates of the present autonomous space system with respect to state-of-the-art. A series of experiments are carried out to consider the efficiency of the proposed control strategy, as long as a number of benchmarks are realized in the same condition to verify and guarantee the strategy performance in both modes of control approaches.

  5. Budgeting-Based Organization of Internal Control

    ERIC Educational Resources Information Center

    Rogulenko, Tatiana; Ponomareva, Svetlana; Bodiaco, Anna; Mironenko, Valentina; Zelenov, Vladimir

    2016-01-01

    The article suggests methodical approaches to the budgeting-based organization of internal control, determines the tasks and subtasks of control that consist in the construction of an efficient system for the making, implementation, control, and analysis of managerial decisions. The organization of responsibility centers by means of implementing…

  6. Predictor-Based Model Reference Adaptive Control

    NASA Technical Reports Server (NTRS)

    Lavretsky, Eugene; Gadient, Ross; Gregory, Irene M.

    2010-01-01

    This paper is devoted to the design and analysis of a predictor-based model reference adaptive control. Stable adaptive laws are derived using Lyapunov framework. The proposed architecture is compared with the now classical model reference adaptive control. A simulation example is presented in which numerical evidence indicates that the proposed controller yields improved transient characteristics.

  7. An examination of the impact of attention-deficit hyperactivity disorder on IQ: a large controlled family-based analysis.

    PubMed

    Biederman, Joseph; Fried, Ronna; Petty, Carter; Mahoney, Laura; Faraone, Stephen V

    2012-10-01

    Although children with attention-deficit hyperactivity disorder (ADHD) have, on average, lower intelligence quotient (IQ) scores than control subjects, the reasons for these deficits remain unknown. Because IQ is highly familial, we investigated whether children with ADHD have a decrement in IQ from expectations based on parental IQ. Subjects were 276 children with ADHD and 239 control subjects of similar age and sex. Expected IQ was calculated based on biological parents' estimated IQ. A significant discrepancy between observed and expected estimated IQ was defined by a child scoring 15 IQ points or more lower than expected, based on parental IQ. Compared with control subjects, children with ADHD were significantly more likely to have lower than expected estimated IQ scores based on parental IQ, though this finding was accounted for by a small subgroup of children with ADHD who had an IQ 15 points or more lower than expected, based on parental IQ. These children were more likely to be female, have higher psychopathological, neuropsychological, educational, and interpersonal deficits, as well as higher rates of perinatal complications. Group differences in IQ scores between children with and without ADHD reported in the literature may be accounted for by a subgroup of children with ADHD who have a large decrement in IQ from expectations based on parental IQ. Although perinatal complications may explain these findings, more work is needed to better understand the etiology of these IQ deficits.

  8. Devices based on controlled magnetic elements

    NASA Astrophysics Data System (ADS)

    Gluzman, P. L.; Milovzorov, V. P.; Iudin, V. V.

    The book is concerned with the theory and optimal design of multifunctional magnetic elements with a controlled transfer ratio and devices based on them. In particular, attention is given to the classification of devices based on controlled magnetic elements and the functional properties of their base structures; devices based on magnetic elements with feedback and external signal control; analysis of single-component controlled magnetic elements with a constant magnetic conductor cross section; and parametric synthesis of optimal functional transducers. The discussion also covers the synthesis of frequency multipliers based on magnetic synthesizers of multiextremal functions; stability and accuracy of controlled magnetic elements and devices based on them; and some applications of devices based on controlled magnetic elements.

  9. Therapeutic Alliance With a Fully Automated Mobile Phone and Web-Based Intervention: Secondary Analysis of a Randomized Controlled Trial

    PubMed Central

    Parker, Gordon; Manicavasagar, Vijaya; Hadzi-Pavlovic, Dusan; Fogarty, Andrea

    2016-01-01

    Background Studies of Internet-delivered psychotherapies suggest that clients report development of a therapeutic alliance in the Internet environment. Because a majority of the interventions studied to date have been therapist-assisted to some degree, it remains unclear whether a therapeutic alliance can develop within the context of an Internet-delivered self-guided intervention with no therapist support, and whether this has consequences for program outcomes. Objective This study reports findings of a secondary analysis of data from 90 participants with mild-to-moderate depression, anxiety, and/or stress who used a fully automated mobile phone and Web-based cognitive behavior therapy (CBT) intervention called “myCompass” in a recent randomized controlled trial (RCT). Methods Symptoms, functioning, and positive well-being were assessed at baseline and post-intervention using the Depression, Anxiety and Stress Scale (DASS), the Work and Social Adjustment Scale (WSAS), and the Mental Health Continuum-Short Form (MHC-SF). Therapeutic alliance was measured at post-intervention using the Agnew Relationship Measure (ARM), and this was supplemented with qualitative data obtained from 16 participant interviews. Extent of participant engagement with the program was also assessed. Results Mean ratings on the ARM subscales were above the neutral midpoints, and the interviewees provided rich detail of a meaningful and collaborative therapeutic relationship with the myCompass program. Whereas scores on the ARM subscales did not correlate with treatment outcomes, participants’ ratings of the quality of their emotional connection with the program correlated significantly and positively with program logins, frequency of self-monitoring, and number of treatment modules completed (r values between .32-.38, P≤.002). The alliance (ARM) subscales measuring perceived empowerment (r=.26, P=.02) and perceived freedom to self-disclose (r=.25, P=.04) also correlated significantly

  10. Unfalsified control based on the ? controller parameterisation

    NASA Astrophysics Data System (ADS)

    Sánchez-Peña, R. S.; Colmegna, P.; Bianchi, F.

    2015-11-01

    This paper presents an implementation of the unfalsified control (UC) method using the Riccati-based parameterisation of ? controllers. The method provides an infinite controller set to (un)falsify the real-time data streams seeking for the best performance. Different sets may be designed to increase the degrees of freedom of the set of controller candidates to perform UC. In general, a set of m central controllers could be designed, each one seeking different objectives and all with their own parameterisation as a function of a stable and bounded transfer matrix. For example, one controller parameterisation could be designed to solve the robust stability of a model set which covers the physical system, therefore guaranteeing feasibility. The implementation requires the online optimisation of either quadratic fractional or quadratic problems, depending on the selection of the cost function. A multi-input, multi-output (MIMO) time-varying model of a permanent magnet synchronous generator illustrates the use of this technique.

  11. Exercise-based rehabilitation for patients with coronary heart disease: systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Taylor, Rod S; Brown, Allan; Ebrahim, Shah; Jolliffe, Judith; Noorani, Hussein; Rees, Karen; Skidmore, Becky; Stone, James A; Thompson, David R; Oldridge, Neil

    2004-05-15

    To review the effectiveness of exercise-based cardiac rehabilitation in patients with coronary heart disease. A systematic review and meta-analysis of randomized controlled trials was undertaken. Databases such as MEDLINE, EMBASE, and the Cochrane Library were searched up to March 2003. Trials with 6 or more months of follow-up were included if they assessed the effects of exercise training alone or in combination with psychological or educational interventions. We included 48 trials with a total of 8940 patients. Compared with usual care, cardiac rehabilitation was associated with reduced all-cause mortality (odds ratio [OR] = 0.80; 95% confidence interval [CI]: 0.68 to 0.93) and cardiac mortality (OR = 0.74; 95% CI: 0.61 to 0.96); greater reductions in total cholesterol level (weighted mean difference, -0.37 mmol/L [-14.3 mg/dL]; 95% CI: -0.63 to -0.11 mmol/L [-24.3 to -4.2 mg/dL]), triglyceride level (weighted mean difference, -0.23 mmol/L [-20.4 mg/dL]; 95% CI: -0.39 to -0.07 mmol/L [-34.5 to -6.2 mg/dL]), and systolic blood pressure (weighted mean difference, -3.2 mm Hg; 95% CI: -5.4 to -0.9 mm Hg); and lower rates of self-reported smoking (OR = 0.64; 95% CI: 0.50 to 0.83). There were no significant differences in the rates of nonfatal myocardial infarction and revascularization, and changes in high- and low-density lipoprotein cholesterol levels and diastolic pressure. Health-related quality of life improved to similar levels with cardiac rehabilitation and usual care. The effect of cardiac rehabilitation on total mortality was independent of coronary heart disease diagnosis, type of cardiac rehabilitation, dose of exercise intervention, length of follow-up, trial quality, and trial publication date. This review confirms the benefits of exercise-based cardiac rehabilitation within the context of today's cardiovascular service provision.

  12. 78 FR 11611 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Parts 1, 16, 106, 110, 114, 117, 120, 123, 129, 179, and 211 RIN 0910-AG36 Current Good Manufacturing Practice and Hazard Analysis and Risk- Based...: Food and Drug Administration, HHS. ACTION: Proposed rule; extension of comment period for...

  13. The Active for Life Year 5 (AFLY5) school-based cluster randomised controlled trial protocol: detailed statistical analysis plan.

    PubMed

    Lawlor, Debbie A; Peters, Tim J; Howe, Laura D; Noble, Sian M; Kipping, Ruth R; Jago, Russell

    2013-07-24

    The Active For Life Year 5 (AFLY5) randomised controlled trial protocol was published in this journal in 2011. It provided a summary analysis plan. This publication is an update of that protocol and provides a detailed analysis plan. This update provides a detailed analysis plan of the effectiveness and cost-effectiveness of the AFLY5 intervention. The plan includes details of how variables will be quality control checked and the criteria used to define derived variables. Details of four key analyses are provided: (a) effectiveness analysis 1 (the effect of the AFLY5 intervention on primary and secondary outcomes at the end of the school year in which the intervention is delivered); (b) mediation analyses (secondary analyses examining the extent to which any effects of the intervention are mediated via self-efficacy, parental support and knowledge, through which the intervention is theoretically believed to act); (c) effectiveness analysis 2 (the effect of the AFLY5 intervention on primary and secondary outcomes 12 months after the end of the intervention) and (d) cost effectiveness analysis (the cost-effectiveness of the AFLY5 intervention). The details include how the intention to treat and per-protocol analyses were defined and planned sensitivity analyses for dealing with missing data. A set of dummy tables are provided in Additional file 1. This detailed analysis plan was written prior to any analyst having access to any data and was approved by the AFLY5 Trial Steering Committee. Its publication will ensure that analyses are in accordance with an a priori plan related to the trial objectives and not driven by knowledge of the data. ISRCTN50133740.

  14. Association between the XRCC3 polymorphisms and breast cancer risk: meta-analysis based on case-control studies.

    PubMed

    He, Xiao-Feng; Wei, Wu; Su, Jiao; Yang, Zi-Xuan; Liu, Yi; Zhang, Ying; Ding, Da-Peng; Wang, Wei

    2012-05-01

    The previous published data on the association between X-ray repair cross-complementing group 3 (XRCC3) T241M, A4541G, and A17893G polymorphisms and breast cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between breast cancer and XRCC3 T241M (21,910 cases and 23,961 controls), A4541G (9,633 cases and 10,994 controls), and A17893G polymorphisms (10,761 cases and 12,235 controls) in different inheritance models. When all the eligible studies were pooled into the meta-analysis of XRCC3 T241M polymorphism, significantly increased risk of breast cancer was observed in recessive model (odds' ratio [OR] = 1.10, 95% confidence interval [CI] = 1.04-1.16) and in additive model (OR = 1.10, 95% CI = 1.03-1.16). No significant association was found between A4541G polymorphism and breast cancer risk. When all the eligible studies were pooled into the meta-analysis of XRCC3 A17893G polymorphism, no significant association was found in any genetic model. Additionally, when one study was deleted in the sensitive analysis, the results of XRCC3 A17893G were changed in the additive model (OR = 0.90, 95% CI = 0.82-0.99) and dominant model (OR = 0.94, 95% CI = 0.89-0.99). In summary, this meta-analysis indicates that T241M polymorphism show an increased breast cancer risk and A17893G polymorphism may be associated with decreased breast cancer risk. A study with the larger sample size is needed to further evaluated gene-environment interaction on XRCC3 T241M, A4541G, and A17893G polymorphisms and breast cancer risk.

  15. Flux based active filter controller

    SciTech Connect

    Bhattacharya, S.; Divan, D.M.; Lorenz, R.D.; Veltman, A. |

    1995-12-31

    This paper presents a synchronous frame flux based control method for a parallel active filer application. The flux based controller directly implements the inverter switchings in the synchronous reference frame by a hysteresis rule based carrierless PWM strategy to achieve high current bandwidth. This paper addresses the issues and impact on parallel active filtering requirements for utility interface of commonly used harmonic front-ends. The synchronous frame flux based controller provides additional insights for harmonic current compensation requirements. Simulation results provide the validation of the flux based active filter controller to meet IEEE 519 recommended harmonic standards for large rated non-linear loads under balanced and unbalanced supply conditions.

  16. Plan delivery quality assurance for CyberKnife: Statistical process control analysis of 350 film-based patient-specific QAs.

    PubMed

    Bellec, J; Delaby, N; Jouyaux, F; Perdrieux, M; Bouvier, J; Sorel, S; Henry, O; Lafond, C

    2017-07-01

    Robotic radiosurgery requires plan delivery quality assurance (DQA) but there has never been a published comprehensive analysis of a patient-specific DQA process in a clinic. We proposed to evaluate 350 consecutive film-based patient-specific DQAs using statistical process control. We evaluated the performance of the process to propose achievable tolerance criteria for DQA validation and we sought to identify suboptimal DQA using control charts. DQAs were performed on a CyberKnife-M6 using Gafchromic-EBT3 films. The signal-to-dose conversion was performed using a multichannel-correction and a scanning protocol that combined measurement and calibration in a single scan. The DQA analysis comprised a gamma-index analysis at 3%/1.5mm and a separate evaluation of spatial and dosimetric accuracy of the plan delivery. Each parameter was plotted on a control chart and control limits were calculated. A capability index (Cpm) was calculated to evaluate the ability of the process to produce results within specifications. The analysis of capability showed that a gamma pass rate of 85% at 3%/1.5mm was highly achievable as acceptance criteria for DQA validation using a film-based protocol (Cpm>1.33). 3.4% of DQA were outside a control limit of 88% for gamma pass-rate. The analysis of the out-of-control DQA helped identify a dosimetric error in our institute for a specific treatment type. We have defined initial tolerance criteria for DQA validations. We have shown that the implementation of a film-based patient-specific DQA protocol with the use of control charts is an effective method to improve patient treatment safety on CyberKnife. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  17. Model-based control of fuel cells:. (1) Regulatory control

    NASA Astrophysics Data System (ADS)

    Golbert, Joshua; Lewin, Daniel R.

    This paper describes a model-based controller for the regulation of a proton exchange membrane (PEM) fuel cell. The model accounts for spatial dependencies of voltage, current, material flows, and temperatures in the fuel channel. Analysis of the process model shows that the effective gain of the process undergoes a sign change in the normal operating range of the fuel cell, indicating that it cannot be stabilized using a linear controller with integral action. Consequently, a nonlinear model-predictive-controller based on a simplified model has been developed, enabling the use of optimal control to satisfy power demands robustly. The models and controller have been realized in the MATLAB and SIMULINK environment. Initial results indicate improved performance and robustness when using model-based control in comparison with that obtained using an adaptive controller.

  18. An Enhanced Model Predictive Control for the Artificial Pancreas Using a Confidence Index Based on Residual Analysis of Past Predictions.

    PubMed

    Laguna Sanz, Alejandro J; Doyle, Francis J; Dassau, Eyal

    2017-05-01

    Model predictive control (MPC) performance depends on the accuracy of the prediction model implemented by the controller. Complex physiology and modeling limitations often prevent the ability to provide long and accurate glucose predictions, which results in the need to account for prediction errors. Optimal insulin dosage by Zone-MPC is calculated by solving an optimization problem in which a scalar index is minimized by penalizing relative input deviations and glucose predictions out of the reference zone. The controller's tuning parameters are the penalties on the input variable (insulin). Positive and negative relative inputs are penalized differently. A dynamic adaptation of the tuning parameters based on the accuracy of the model in recent history is implemented in this article and compared in silico to aggressive and conservative tunings of the same controller structure. Similar average glucose and time in the safe glucose range (70-180 mg/dL) are achieved for the adaptive design and traditional controller configurations. However, percentage time under 70 mg/dL is significantly reduced, both for announced meals using bolus compensation and unannounced meals with a meal detection algorithm triggered bolus. No differences in the average insulin delivered were observed between the adaptive design and the conservative or aggressive tuning for the bolus strategy, and the adaptive controller delivered less insulin in the other scenario considered. The adaptive strategy provides safe and effective glucose management as well as significant reduction of hypoglycemia events. No abnormal insulin delivery profiles were observed upon the application of the adaptive strategy.

  19. Controllability analysis of networks

    NASA Astrophysics Data System (ADS)

    Lombardi, Anna; Hörnquist, Michael

    2007-05-01

    The concept of controllability of linear systems from control theory is applied to networks inspired by biology. A node is in this context controllable if an external signal can be applied which can adjust the level (e.g., protein concentration) of the node in a finite time to an arbitrary value, regardless of the levels of the other nodes. The property of being downstream of the node to which the input is applied turns out to be a necessary but not a sufficient condition for being controllable. An interpretation of the controllability matrix, when applied to networks, is also given. Finally, two case studies are provided in order to better explain the concepts, as well as some results for a gene regulatory network of fission yeast.

  20. Generator Control Based on Equilibrium Point Analysis of Standard One-Machine Infinite-Bus System Model—Comparison with PSS—

    NASA Astrophysics Data System (ADS)

    Kawamoto, Shunji; Zhang, Jian; Yamamoto, Hiroyoshi; Fujimoto, Koji

    We have recently proposed a new controller based on the equilibrium point analysis for model power systems. In this paper, first the Japanese standard one-machine infinite-bus system model is formulated, and the equilibrium points are analyzed. Next, complementary control inputs for AVR and GOV with limiters of the model system are determined on the basis of the analysis. Finally, it is shown that the unstable equilibrium point is eliminated by adding the proposed inputs, and then the critical clearing time can be improved in comparison with PSS of the standard model.

  1. The analysis of monitoring control point displacement of Sermo Dam based on the 2015-2016 GNSS data

    NASA Astrophysics Data System (ADS)

    Yulaikhah, Nurrohmat, W.; Prijono, N.; Bambang, K. C.; Waljiyanto, Agus, D. A.; Taftazani, M. I.

    2017-07-01

    Sermo dam has operated for 20 years. This dam has a great benefit, especially as a water storage for water supply, irrigation and flood prevention. For the purposes of Sermo dam deformation monitoring, the control network was built around the Sermo dam in 2010. Then, this network was developed in 2015 by adding 5 new control points. For the time being, the network consists of 8 existing control points (micro) and 5 new control points (macro). The aim of the study is to monitor the control network displacement in the period of 2015 to 2016 based on GNSS observation data.GNSS measurement were conducted at 9 to10 of May 2015 and 12 to 15 of May 2016. The data observation was processed using GAMIT/GBLOK scientific software referenced to IGS station to determine the coordinates and its standard deviation. Further, horizontal and vertical displacement was analyzed by comparing with 2.5 times the standard deviation. The results showed that within a year, the coordinate difference varied from 0.12 to 1.68 cm on the N component, 0.21 to 0.65 cm on the E component, while the U component (the vertical displacement) have greater one, varied from 2.71 to 16.34 cm. Six control points (MAK2, MAK3, BMB2, BMB5, BMS2 and BMS5) have significant different in the horizontal displacement and six control points have significant different in vertical displacement (MAK5, BMB1, BMB2, BMS1, BMS2 and BMS3). In general, the horizontal displacement tends toward southeast. However, for obtaining more accurate and realistic results, further evaluation is required in the processing strategy such as the use of local control point as reference.

  2. Automatic control of a robot camera for broadcasting based on cameramen's techniques and subjective evaluation and analysis of reproduced images.

    PubMed

    Kato, D; Katsuura, T; Koyama, H

    2000-03-01

    With the goal of achieving an intelligent robot camera system that can take dynamic images automatically through humanlike, natural camera work, we analyzed how images were shot, subjectively evaluated reproduced images, and examined effects of camerawork, using camera control technique as a parameter. It was found that (1) A high evaluation is obtained when human-based data are used for the position adjusting velocity curve of the target; (2) Evaluation scores are relatively high for images taken with feedback-feedforward camera control method for target movement in one direction; (3) Keeping the target within the image area using the control method that imitates human camera handling becomes increasingly difficult when the target changes both direction and velocity and becomes bigger and faster, and (4) The mechanical feedback method can cope with rapid changes in the target's direction and velocity, constantly keeping the target within the image area, though the viewer finds the image rather mechanical as opposed to humanlike.

  3. Controlling Wind Turbines for Secondary Frequency Regulation: An Analysis of AGC Capabilities Under New Performance Based Compensation Policy: Preprint

    SciTech Connect

    Aho, J.; Pao, L. Y.; Fleming, P.; Ela, E.

    2015-02-01

    As wind energy becomes a larger portion of the world's energy portfolio there has been an increased interest for wind turbines to control their active power output to provide ancillary services which support grid reliability. One of these ancillary services is the provision of frequency regulation, also referred to as secondary frequency control or automatic generation control (AGC), which is often procured through markets which recently adopted performance-based compensation. A wind turbine with a control system developed to provide active power ancillary services can be used to provide frequency regulation services. Simulations have been performed to determine the AGC tracking performance at various power schedule set-points, participation levels, and wind conditions. The performance metrics used in this study are based on those used by several system operators in the US. Another metric that is analyzed is the damage equivalent loads (DELs) on turbine structural components, though the impacts on the turbine electrical components are not considered. The results of these single-turbine simulations show that high performance scores can be achieved when there is sufficient wind resource available. The capability of a wind turbine to rapidly and accurately follow power commands allows for high performance even when tracking rapidly changing AGC signals. As the turbine de-rates to meet decreased power schedule set-points there is a reduction in the DELs, and the participation in frequency regulation has a negligible impact on these loads.

  4. Controlling Wind Turbines for Secondary Frequency Regulation: An Analysis of AGC Capabilities Under New Performance Based Compensation Policy

    SciTech Connect

    Aho, Jacob; Pao, Lucy Y.; Fleming, Paul; Ela, Erik

    2014-11-13

    As wind energy becomes a larger portion of the world's energy portfolio there has been an increased interest for wind turbines to control their active power output to provide ancillary services which support grid reliability. One of these ancillary services is the provision of frequency regulation, also referred to as secondary frequency control or automatic generation control (AGC), which is often procured through markets which recently adopted performance-based compensation. A wind turbine with a control system developed to provide active power ancillary services can be used to provide frequency regulation services. Simulations have been performed to determine the AGC tracking performance at various power schedule set-points, participation levels, and wind conditions. The performance metrics used in this study are based on those used by several system operators in the US. Another metric that is analyzed is the damage equivalent loads (DELs) on turbine structural components, though the impacts on the turbine electrical components are not considered. The results of these single-turbine simulations show that high performance scores can be achieved when there are insufficient wind resources available. The capability of a wind turbine to rapidly and accurately follow power commands allows for high performance even when tracking rapidly changing AGC signals. As the turbine de-rates to meet decreased power schedule set-points there is a reduction in the DELs, and the participation in frequency regulation has a negligible impact on these loads.

  5. CFD-based aero-optical analysis of flow fields over two-dimensional cavities with active flow control

    NASA Astrophysics Data System (ADS)

    Tan, Yan

    Prediction and control of optical wave front distortions and aberrations in a high energy laser beam due to interaction with an unsteady highly non-uniform flow field is of great importance in the development of directed energy weapon systems for Unmanned Air Vehicles (UAV). The unsteady shear layer over the weapons bay cavity is the primary cause of this distortion of the optical wave front. The large scale vortical structure of the shear layer over the cavity can be significantly reduced by employing an active flow control technique combined with passive flow control. This dissertation explores various active and passive control methods to suppress the cavity oscillations and thereby improve the aero-optics of cavity flow. In active flow control technique, a steady or a pulsed jet is applied at the sharp leading edge of cavities of different aspect ratios L/D (=2, 4, 15), where L and D are the width and the depth of a cavity respectively. In the passive flow control approach, the sharp leading or trailing edge of the cavity is modified into a round edge of different radii. Both of these active and passive flow control approaches are studied independently and in combination. Numerical simulations are performed, with and without active flow control for subsonic free stream flow past two-dimensional sharp and round leading or trailing edge cavities using Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with a two-equation Shear Stress Transport (SST) turbulence model or a hybrid SST/Large Eddy Simulation (LES) model. Aero-optical analysis is developed and applied to all the simulation cases. Index of refraction and Optical Path Difference (OPD) are compared for flow fields without and with active flow control. Root-Mean-Square (RMS) value of OPD is calculated and compared with the experimental data, where available. The effect of steady and pulsed blowing on buffet loading on the downstream face of the cavity is also computed. Using the numerical

  6. Attack Methodology Analysis: Emerging Trends in Computer-Based Attack Methodologies and Their Applicability to Control System Networks

    SciTech Connect

    Bri Rolston

    2005-06-01

    Threat characterization is a key component in evaluating the threat faced by control systems. Without a thorough understanding of the threat faced by critical infrastructure networks, adequate resources cannot be allocated or directed effectively to the defense of these systems. Traditional methods of threat analysis focus on identifying the capabilities and motivations of a specific attacker, assessing the value the adversary would place on targeted systems, and deploying defenses according to the threat posed by the potential adversary. Too many effective exploits and tools exist and are easily accessible to anyone with access to an Internet connection, minimal technical skills, and a significantly reduced motivational threshold to be able to narrow the field of potential adversaries effectively. Understanding how hackers evaluate new IT security research and incorporate significant new ideas into their own tools provides a means of anticipating how IT systems are most likely to be attacked in the future. This research, Attack Methodology Analysis (AMA), could supply pertinent information on how to detect and stop new types of attacks. Since the exploit methodologies and attack vectors developed in the general Information Technology (IT) arena can be converted for use against control system environments, assessing areas in which cutting edge exploit development and remediation techniques are occurring can provide significance intelligence for control system network exploitation, defense, and a means of assessing threat without identifying specific capabilities of individual opponents. Attack Methodology Analysis begins with the study of what exploit technology and attack methodologies are being developed in the Information Technology (IT) security research community within the black and white hat community. Once a solid understanding of the cutting edge security research is established, emerging trends in attack methodology can be identified and the gap between

  7. Analysis of Aircraft Control Performance using a Fuzzy Rule Base Representation of the Cooper-Harper Aircraft Handling Quality Rating

    NASA Technical Reports Server (NTRS)

    Tseng, Chris; Gupta, Pramod; Schumann, Johann

    2006-01-01

    The Cooper-Harper rating of Aircraft Handling Qualities has been adopted as a standard for measuring the performance of aircraft since it was introduced in 1966. Aircraft performance, ability to control the aircraft, and the degree of pilot compensation needed are three major key factors used in deciding the aircraft handling qualities in the Cooper- Harper rating. We formulate the Cooper-Harper rating scheme as a fuzzy rule-based system and use it to analyze the effectiveness of the aircraft controller. The automatic estimate of the system-level handling quality provides valuable up-to-date information for diagnostics and vehicle health management. Analyzing the performance of a controller requires a set of concise design requirements and performance criteria. Ir, the case of control systems fm a piloted aircraft, generally applicable quantitative design criteria are difficult to obtain. The reason for this is that the ultimate evaluation of a human-operated control system is necessarily subjective and, with aircraft, the pilot evaluates the aircraft in different ways depending on the type of the aircraft and the phase of flight. In most aerospace applications (e.g., for flight control systems), performance assessment is carried out in terms of handling qualities. Handling qualities may be defined as those dynamic and static properties of a vehicle that permit the pilot to fully exploit its performance in a variety of missions and roles. Traditionally, handling quality is measured using the Cooper-Harper rating and done subjectively by the human pilot. In this work, we have formulated the rules of the Cooper-Harper rating scheme as fuzzy rules with performance, control, and compensation as the antecedents, and pilot rating as the consequent. Appropriate direct measurements on the controller are related to the fuzzy Cooper-Harper rating system: a stability measurement like the rate of change of the cost function can be used as an indicator if the aircraft is under

  8. Analysis of Aircraft Control Performance using a Fuzzy Rule Base Representation of the Cooper-Harper Aircraft Handling Quality Rating

    NASA Technical Reports Server (NTRS)

    Tseng, Chris; Gupta, Pramod; Schumann, Johann

    2006-01-01

    The Cooper-Harper rating of Aircraft Handling Qualities has been adopted as a standard for measuring the performance of aircraft since it was introduced in 1966. Aircraft performance, ability to control the aircraft, and the degree of pilot compensation needed are three major key factors used in deciding the aircraft handling qualities in the Cooper- Harper rating. We formulate the Cooper-Harper rating scheme as a fuzzy rule-based system and use it to analyze the effectiveness of the aircraft controller. The automatic estimate of the system-level handling quality provides valuable up-to-date information for diagnostics and vehicle health management. Analyzing the performance of a controller requires a set of concise design requirements and performance criteria. Ir, the case of control systems fm a piloted aircraft, generally applicable quantitative design criteria are difficult to obtain. The reason for this is that the ultimate evaluation of a human-operated control system is necessarily subjective and, with aircraft, the pilot evaluates the aircraft in different ways depending on the type of the aircraft and the phase of flight. In most aerospace applications (e.g., for flight control systems), performance assessment is carried out in terms of handling qualities. Handling qualities may be defined as those dynamic and static properties of a vehicle that permit the pilot to fully exploit its performance in a variety of missions and roles. Traditionally, handling quality is measured using the Cooper-Harper rating and done subjectively by the human pilot. In this work, we have formulated the rules of the Cooper-Harper rating scheme as fuzzy rules with performance, control, and compensation as the antecedents, and pilot rating as the consequent. Appropriate direct measurements on the controller are related to the fuzzy Cooper-Harper rating system: a stability measurement like the rate of change of the cost function can be used as an indicator if the aircraft is under

  9. A Strategy for Quality Control of Menispermum dauricum DC Based on Cytotoxic Activity and HPLC Fingerprint Analysis

    PubMed Central

    Liu, L. J.; Liu, J. N.

    2016-01-01

    The rhizome of Menispermum dauricum DC known as a traditional Chinese medicine, with high content of alkaloids, has been found to possess antitumor activity. In this research, an attempt to correlate fingerprinting with bioactivity was made for quality control of M. dauricum. Firstly, the cytotoxicity of extracts from ten batches of samples against human breast MCF-7 cancer cells was estimated by [3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazoliumbromide] assay. Then, cytotoxic activity-integrated fingerprints were established by high performance liquid chromatography. Eight peaks were selected as the common peaks to evaluate the similarities of samples and hierarchical clustering analysis was used to identify and classify different samples into groups. Assays for determinations of total alkaloids and dauricine contents enabled cytotoxicity coefficient of each extract. The potential usefulness of employing cytotoxicity coefficient was investigated by a combination of Pearson correlation coefficients and multiple linear regression analysis as being the reliable parameter to evaluate the herbal extracts. The results indicated that the level of dauricine (peak 8 in the fingerprint) correlated closely with cytotoxicity and played a significant role in the cytotoxicity of Bei Dou-Gen and could be related to its antitumor properties. It is proposed that the cytotoxicity coefficient value with a cytotoxic activity-integrated fingerprint of key biomarkers (dauricine) may be useful indicators to adopt for the quality control of M. dauricum. The analysis of cytotoxic-activity-integrated fingerprint could correlate fingerprinting with bioactivities and would provide a reasonable strategy for quality control of complex mixture of herbal medicines. PMID:27168693

  10. A Strategy for Quality Control of Menispermum dauricum DC Based on Cytotoxic Activity and HPLC Fingerprint Analysis.

    PubMed

    Liu, L J; Liu, J N

    2016-01-01

    The rhizome of Menispermum dauricum DC known as a traditional Chinese medicine, with high content of alkaloids, has been found to possess antitumor activity. In this research, an attempt to correlate fingerprinting with bioactivity was made for quality control of M. dauricum. Firstly, the cytotoxicity of extracts from ten batches of samples against human breast MCF-7 cancer cells was estimated by [3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazoliumbromide] assay. Then, cytotoxic activity-integrated fingerprints were established by high performance liquid chromatography. Eight peaks were selected as the common peaks to evaluate the similarities of samples and hierarchical clustering analysis was used to identify and classify different samples into groups. Assays for determinations of total alkaloids and dauricine contents enabled cytotoxicity coefficient of each extract. The potential usefulness of employing cytotoxicity coefficient was investigated by a combination of Pearson correlation coefficients and multiple linear regression analysis as being the reliable parameter to evaluate the herbal extracts. The results indicated that the level of dauricine (peak 8 in the fingerprint) correlated closely with cytotoxicity and played a significant role in the cytotoxicity of Bei Dou-Gen and could be related to its antitumor properties. It is proposed that the cytotoxicity coefficient value with a cytotoxic activity-integrated fingerprint of key biomarkers (dauricine) may be useful indicators to adopt for the quality control of M. dauricum. The analysis of cytotoxic-activity-integrated fingerprint could correlate fingerprinting with bioactivities and would provide a reasonable strategy for quality control of complex mixture of herbal medicines.

  11. Comparison of dimension reduction-based logistic regression models for case-control genome-wide association study: principal components analysis vs. partial least squares

    PubMed Central

    Yi, Honggang; Wo, Hongmei; Zhao, Yang; Zhang, Ruyang; Dai, Junchen; Jin, Guangfu; Ma, Hongxia; Wu, Tangchun; Hu, Zhibin; Lin, Dongxin; Shen, Hongbing; Chen, Feng

    2015-01-01

    Abstract With recent advances in biotechnology, genome-wide association study (GWAS) has been widely used to identify genetic variants that underlie human complex diseases and traits. In case-control GWAS, typical statistical strategy is traditional logistical regression (LR) based on single-locus analysis. However, such a single-locus analysis leads to the well-known multiplicity problem, with a risk of inflating type I error and reducing power. Dimension reduction-based techniques, such as principal component-based logistic regression (PC-LR), partial least squares-based logistic regression (PLS-LR), have recently gained much attention in the analysis of high dimensional genomic data. However, the performance of these methods is still not clear, especially in GWAS. We conducted simulations and real data application to compare the type I error and power of PC-LR, PLS-LR and LR applicable to GWAS within a defined single nucleotide polymorphism (SNP) set region. We found that PC-LR and PLS can reasonably control type I error under null hypothesis. On contrast, LR, which is corrected by Bonferroni method, was more conserved in all simulation settings. In particular, we found that PC-LR and PLS-LR had comparable power and they both outperformed LR, especially when the causal SNP was in high linkage disequilibrium with genotyped ones and with a small effective size in simulation. Based on SNP set analysis, we applied all three methods to analyze non-small cell lung cancer GWAS data. PMID:26243516

  12. Process Analysis Via Accuracy Control

    DTIC Science & Technology

    1982-02-01

    0 1 4 3 NDARDS THE NATIONAL February 1982 Process Analysis Via Accuracy Control RESEARCH PROG RAM U.S. DEPARTMENT OF TRANSPORTATION Maritime...SUBTITLE Process Analysis Via Accuracy Control 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...examples are contained in Appendix C. Included, are examples of how “A/C” process - analysis leads to design improvement and how a change in sequence can

  13. Orientation control and domain structure analysis of {100}-oriented epitaxial ferroelectric orthorhombic HfO2-based thin films

    NASA Astrophysics Data System (ADS)

    Katayama, Kiliha; Shimizu, Takao; Sakata, Osami; Shiraishi, Takahisa; Nakamura, Shogo; Kiguchi, Takanori; Akama, Akihiro; Konno, Toyohiko J.; Uchida, Hiroshi; Funakubo, Hiroshi

    2016-04-01

    Orientation control of {100}-oriented epitaxial orthorhombic 0.07YO1.5-0.93HfO2 films grown by pulsed laser deposition was investigated. To achieve in-plane lattice matching, indium tin oxide (ITO) and yttria-stabilized zirconia (YSZ) were selected as underlying layers. We obtained (100)- and (001)/(010)-oriented films on ITO and YSZ, respectively. Ferroelastic domain formation was confirmed for both films by X-ray diffraction using the superlattice diffraction that appeared only for the orthorhombic symmetry. The formation of ferroelastic domains is believed to be induced by the tetragonal-orthorhombic phase transition upon cooling the films after deposition. The present results demonstrate that the orientation of HfO2-based ferroelectric films can be controlled in the same manner as that of ferroelectric films composed of conventional perovskite-type material such as Pb(Zr, Ti)O3 and BiFeO3.

  14. The SNP rs931794 in 15q25.1 Is Associated with Lung Cancer Risk: A Hospital-Based Case-Control Study and Meta-Analysis

    PubMed Central

    Hu, Weiguo; Lu, Xuzai; Wang, Zhenling; Gong, Hongyun; Xu, Tangpeng; Chen, Xueqin; Xu, Bin; Liu, Cheng; Sun, Yun; Gong, Yajie; Yang, Yang; Zhu, Ying

    2015-01-01

    Background Lung cancer is one of the most common human malignant diseases and the leading cause of cancer death worldwide. The rs931794, a SNP located in 15q25.1, has been suggested to be associated with lung cancer risk. Nevertheless, several genetic association studies yielded controversial results. Methods and Findings A hospital-based case-control study involving 611 cases and 1062 controls revealed the variant of rs931794 was related to increased lung cancer risk. Stratified analyses revealed the G allele was significantly associated with lung cancer risk among smokers. Following meta-analysis including 6616 cases and 7697 controls confirmed the relevance of rs931794 variant with increased lung cancer risk once again. Heterogeneity should be taken into account when interpreting the consequences. Stratified analysis found ethnicity, histological type and genotyping method were not the sources of between-study heterogeneity. Further sensitivity analysis revealed that the study “Hsiung et al (2010)” might be the major contributor to heterogeneity. Cumulative meta-analysis showed the trend was increasingly obvious with adding studies, confirming the significant association. Conclusions Results from our current case-control study and meta-analysis offered insight of association between rs931794 and lung cancer risk, suggesting the variant of rs931794 might be related with increased lung cancer risk. PMID:26079375

  15. Population-based linkage analysis of schizophrenia and bipolar case-control cohorts identifies a potential susceptibility locus on 19q13.

    PubMed

    Francks, C; Tozzi, F; Farmer, A; Vincent, J B; Rujescu, D; St Clair, D; Muglia, P

    2010-03-01

    Population-based linkage analysis is a new method for analysing genomewide single nucleotide polymorphism (SNP) genotype data in case-control samples, which does not assume a common disease, common variant model. The genome is scanned for extended segments that show increased identity-by-descent sharing within case-case pairs, relative to case-control or control-control pairs. The method is robust to allelic heterogeneity and is suited to mapping genes which contain multiple, rare susceptibility variants of relatively high penetrance. We analysed genomewide SNP datasets for two schizophrenia case-control cohorts, collected in Aberdeen (461 cases, 459 controls) and Munich (429 cases, 428 controls). Population-based linkage testing must be performed within homogeneous samples and it was therefore necessary to analyse the cohorts separately. Each cohort was first subjected to several procedures to improve genetic homogeneity, including identity-by-state outlier detection and multidimensional scaling analysis. When testing only cases who reported a positive family history of major psychiatric disease, consistent with a model of strongly penetrant susceptibility alleles, we saw a distinct peak on chromosome 19q in both cohorts that appeared in meta-analysis (P=0.000016) to surpass the traditional level for genomewide significance for complex trait linkage. The linkage signal was also present in a third case-control sample for familial bipolar disorder, such that meta-analysing all three datasets together yielded a linkage P=0.0000026. A model of rare but highly penetrant disease alleles may be more applicable to some instances of major psychiatric diseases than the common disease common variant model, and we therefore suggest that other genome scan datasets are analysed with this new, complementary method.

  16. Design of LabVIEW-based software for the control of sequential injection analysis instrumentation for the determination of morphine.

    PubMed

    Lenehan, Claire E; Barnett, Neil W; Lewis, Simon W

    2002-01-01

    LabVIEW-based software for the automation of a sequential injection analysis instrument for the determination of morphine is presented. Detection was based on its chemiluminescence reaction with acidic potassium permanganate in the presence of sodium polyphosphate. The calibration function approximated linearity (range 5 x 10(-10) to 5 x 10(-6) M) with a line of best fit of y=1.05(x)+8.9164 (R(2) =0.9959), where y is the log10 signal (mV) and x is the log10 morphine concentration (M). Precision, as measured by relative standard deviation, was 0.7% for five replicate analyses of morphine standard (5 x 10(-8) M). The limit of detection (3sigma) was determined as 5 x 10(-11) M morphine.

  17. Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies.

    PubMed

    Taylor, Luke E; Swerdfeger, Amy L; Eslick, Guy D

    2014-06-17

    There has been enormous debate regarding the possibility of a link between childhood vaccinations and the subsequent development of autism. This has in recent times become a major public health issue with vaccine preventable diseases increasing in the community due to the fear of a 'link' between vaccinations and autism. We performed a meta-analysis to summarise available evidence from case-control and cohort studies on this topic (MEDLINE, PubMed, EMBASE, Google Scholar up to April, 2014). Eligible studies assessed the relationship between vaccine administration and the subsequent development of autism or autism spectrum disorders (ASD). Two reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus with another author. Five cohort studies involving 1,256,407 children, and five case-control studies involving 9,920 children were included in this analysis. The cohort data revealed no relationship between vaccination and autism (OR: 0.99; 95% CI: 0.92 to 1.06) or ASD (OR: 0.91; 95% CI: 0.68 to 1.20), nor was there a relationship between autism and MMR (OR: 0.84; 95% CI: 0.70 to 1.01), or thimerosal (OR: 1.00; 95% CI: 0.77 to 1.31), or mercury (Hg) (OR: 1.00; 95% CI: 0.93 to 1.07). Similarly the case-control data found no evidence for increased risk of developing autism or ASD following MMR, Hg, or thimerosal exposure when grouped by condition (OR: 0.90, 95% CI: 0.83 to 0.98; p=0.02) or grouped by exposure type (OR: 0.85, 95% CI: 0.76 to 0.95; p=0.01). Findings of this meta-analysis suggest that vaccinations are not associated with the development of autism or autism spectrum disorder. Furthermore, the components of the vaccines (thimerosal or mercury) or multiple vaccines (MMR) are not associated with the development of autism or autism spectrum disorder. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Risk of intussusception following rotavirus vaccination: An evidence based meta-analysis of cohort and case-control studies.

    PubMed

    Kassim, Priya; Eslick, Guy D

    2017-07-24

    International post-licensure studies on rotavirus vaccines have identified an increased risk of intussusception in infants after administration. The first developed rotavirus vaccine (Rotashield (RRV-TV)) was suspended post-licensure in 1999 after an association with intussusception was found. The currently available second-generation rotavirus vaccines (Rotateq (RV5) and Rotarix (RV1)), are recommended as a routine vaccine by the World Health Organisation (WHO). Post-licensure studies of these vaccines have shown a smaller but temporal increased risk for developing intussusception. A meta-analysis was performed to summarise available evidence and to give an overall risk of developing intussusception from case-control and cohort studies for all rotavirus vaccines that have been manufactured up to date. A search was conducted on MEDLINE, PubMed, EMBASE and Google Scholar up to May 2017. Eligible studies assessed the relationship between the rotavirus vaccine administration and subsequent development of intussusception both after receiving the first dose and after receiving all doses combined. Data was extracted on study characteristics, methods and outcomes. Results were pooled using the random-effect model. Six cohort studies involving 4506265 total first doses and five case-control studies involving a total sample of 9643 children were included in this analysis. The cohort data revealed that there was an associated increased risk of intussusception after the first 7days post first dose of the vaccine (RR:3.71, 95% CI:1.08-12.69) and after receiving all doses of the rotavirus vaccine (RR:3.47, 95% CI:1.23-9.78). Similarly, the case-control data found an increased risk of intussusception following the first dose (OR: 8.45, 95% CI: 4.08-17.50) and following all doses (OR: 1.59, 95% CI: 1.11-2.27). Findings of this meta-analysis suggest that the rotavirus vaccine is associated with an increased risk on the development of intussusception, principally seen after

  19. The association between the APE1 Asp148Glu polymorphism and prostate cancer susceptibility: a meta-analysis based on case-control studies.

    PubMed

    Zhou, Xue; Wei, Li; Jiao, Guangjun; Gao, Wei; Ying, Mingzhen; Wang, Ning; Wang, Yajie; Liu, Chuan

    2015-02-01

    The apurinic/apyrimidinic endonuclease 1 (APE1) plays important roles in the repair of DNA damage and adducts. However, previous case-control studies on the association between the APE1 Asp148Glu polymorphism and prostate cancer susceptibility have shown contradictory results, this meta-analysis was performed to draw a more precise estimation of the relationship. A total of seven case-control studies including 1,294 cases and 1,762 controls were included for analysis. In overall, no significant associations were found in all genetic models (GG vs. TT: OR = 1.16, 95 % CI 0.89-1.52; TG vs. TT: OR = 1.04, 95 % CI 0.81-1.35; the dominant model GG + TG vs. TT: OR = 1.12, 95 % CI 0.96-1.30; the recessive model GG vs. TG + TT: OR = 0.90, 95 % CI 0.77-1.04); in the subgroup by source of control, we found a significant association for the dominant model in Hospital-based subgroup (OR = 1.34, 95 % CI 1.08-1.68), no significant associations were found in other models in the subgroups. This meta-analysis suggested that the APE1 Asp148Glu polymorphism was a risk factor for prostate cancer susceptibility in Hospital-based population.

  20. Analysis and Simulation of Traffic Control for Resource Management in DVB-Based Broadband Satellite Access Networks

    NASA Astrophysics Data System (ADS)

    Impemba, Ernesto; Inzerilli, Tiziano

    2003-07-01

    Integration of satellite access networks with the Internet is seen as a strategic goal to achieve in order to provide ubiquitous broadband access to Internet services in Next Generation Networks (NGNs). One of the main interworking aspects which has been most studied is an efficient management of satellite resources, i.e. bandwidth and buffer space, in order to satisfy most demanding application requirements as to delay control and bandwidth assurance. In this context, resource management in DVB-S/DVB-RCS satellite technologies, emerging technologies for broadband satellite access and transport of IP applications, is a research issue largely investigated as a means to provide efficient bi-directional communications across satellites. This is in particular one of the principal goals of the SATIP6 project, sponsored within the 5th EU Research Programme Framework, i.e. IST. In this paper we present a possible approach to efficiently exploit bandwidth, the most critical resource in a broadband satellite access network, while pursuing satisfaction of delay and bandwidth requirements for applications with guaranteed QoS through a traffic control architecture to be implemented in ground terminals. Performance of this approach is assessed in terms of efficient exploitation of the uplink bandwidth and differentiation and minimization of queuing delays for most demanding applications over a time-varying capacity. Opnet simulations is used as analysis tool.

  1. Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations

    PubMed Central

    Cheng, Xuemin; Yang, Yikang; Hao, Qun

    2016-01-01

    The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1–5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control. PMID:27763515

  2. Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations.

    PubMed

    Cheng, Xuemin; Yang, Yikang; Hao, Qun

    2016-10-17

    The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1-5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

  3. Online machining error estimation method of numerical control gear grinding machine tool based on data analysis of internal sensors

    NASA Astrophysics Data System (ADS)

    Zhao, Fei; Zhang, Chi; Yang, Guilin; Chen, Chinyin

    2016-12-01

    This paper presents an online estimation method of cutting error by analyzing of internal sensor readings. The internal sensors of numerical control (NC) machine tool are selected to avoid installation problem. The estimation mathematic model of cutting error was proposed to compute the relative position of cutting point and tool center point (TCP) from internal sensor readings based on cutting theory of gear. In order to verify the effectiveness of the proposed model, it was simulated and experimented in gear generating grinding process. The cutting error of gear was estimated and the factors which induce cutting error were analyzed. The simulation and experiments verify that the proposed approach is an efficient way to estimate the cutting error of work-piece during machining process.

  4. The LDLR locus in Alzheimer's disease: a family-based study and meta-analysis of case-control data.

    PubMed

    Bertram, Lars; Hsiao, Monica; McQueen, Matthew B; Parkinson, Michele; Mullin, Kristina; Blacker, Deborah; Tanzi, Rudolph E

    2007-01-01

    Genetic linkage studies suggest the presence of an Alzheimer's disease (AD) risk gene on chromosome 19, acting independently of apolipoprotein E (apoE), a known AD risk factor on 19q13. The low density lipoprotein receptor (LDLR) is an interesting candidate because it maps within the linked interval, and is intimately involved in cholesterol homeostasis and the function of apoE. We tested three previously reported single nucleotide polymorphisms (SNPs) within LDLR in a large sample of discordant sibships from multiplex AD families, and failed to find evidence for genetic association with disease risk. In addition, we performed meta-analyses for SNP rs5925 on published data from five independent case control samples, but did not detect any significant summary odds ratios. Based on our data, it seems unlikely that these genetic variants in LDLR make a significant contribution to AD risk in the general population.

  5. Orientation control and domain structure analysis of {100}-oriented epitaxial ferroelectric orthorhombic HfO{sub 2}-based thin films

    SciTech Connect

    Katayama, Kiliha; Shimizu, Takao; Sakata, Osami; Shiraishi, Takahisa; Nakamura, Shogo; Kiguchi, Takanori; Akama, Akihiro; Konno, Toyohiko J.; Uchida, Hiroshi; Funakubo, Hiroshi

    2016-04-07

    Orientation control of {100}-oriented epitaxial orthorhombic 0.07YO{sub 1.5}-0.93HfO{sub 2} films grown by pulsed laser deposition was investigated. To achieve in-plane lattice matching, indium tin oxide (ITO) and yttria-stabilized zirconia (YSZ) were selected as underlying layers. We obtained (100)- and (001)/(010)-oriented films on ITO and YSZ, respectively. Ferroelastic domain formation was confirmed for both films by X-ray diffraction using the superlattice diffraction that appeared only for the orthorhombic symmetry. The formation of ferroelastic domains is believed to be induced by the tetragonal–orthorhombic phase transition upon cooling the films after deposition. The present results demonstrate that the orientation of HfO{sub 2}-based ferroelectric films can be controlled in the same manner as that of ferroelectric films composed of conventional perovskite-type material such as Pb(Zr, Ti)O{sub 3} and BiFeO{sub 3}.

  6. Agent-Based Cooperative Control

    DTIC Science & Technology

    2005-12-01

    518. [91] A. Robertson, G. Inalhan, J. P. How, “ Formation control strategies for a separated spacecraft interferometer,” in Proc. of the 1999...100] M. Tillerson and J. P. How, “Advanced guidance algorithms for spacecraft formation -keeping,” in Proc. of the 2002 American Control Conference...based nonlinear control theory. Potential Field Addresses: issues of desired interaction such as coordination, formation , and collision

  7. Controls on mineralisation in the Sierra Foothills gold province, central California, USA: A GIS-based reconnaissance prospectivity analysis

    USGS Publications Warehouse

    Bierlein, F.P.; Northover, H.J.; Groves, D.I.; Goldfarb, R.J.; Marsh, E.E.

    2008-01-01

    The assessment of spatial relationships between the location, abundance and size of orogenic-gold deposits in the highly endowed Sierra Foothills gold province in California, via the combination of field studies and a GIS-based analysis, illustrates the power of such an approach to the characterisation of important parameters of mineral systems, and the prediction of districts likely to host economic mineralisation. Regional- to deposit-scale reconnaissance mapping suggests that deposition of gold-bearing quartz veins occurred in second- and third-order, east-over-west thrusts during regional east - west compression and right-lateral transpression. At the district-scale, significant zones of mineralisation correspond with such transpressional reactivation zones and dilational jogs that developed during the Late Jurassic - Early Cretaceous along the misaligned segments of first-order faults throughout the Sierra Nevada Foothills Metamorphic Belt. Field-based observations and interpretation of GIS data (including solid geology, structural elements, deposit locations, magnetics, gravity) also highlight the importance of structural permeability contrasts, rheological gradients, and variations in fault orientation for localising mineralisation. Although this approach confirms empirical findings and produces promising results at the province scale, enhanced geological, structural, geophysical and geochronological data density is required to generate regionally consistent, high-quality input layers that improve predictive targeting at the goldfield to deposit-scale.

  8. Flow injection analysis-based methodology for automatic on-line monitoring and quality control for biodiesel production.

    PubMed

    Pinzi, S; Priego Capote, F; Ruiz Jiménez, J; Dorado, M P; Luque de Castro, M D

    2009-01-01

    An automated on-line approach based on determination of free and bound glycerol was here proposed to monitor biodiesel production. The method was based on liquid-liquid extraction of glycerol from the biodiesel to an aqueous ethanolic phase in which glycerol is oxidized to formaldehyde with meta periodate with subsequent reaction with acetylacetone. The reaction product was photometrically measured at 410 nm. Free and bound glycerol were differentiated by glycerides hydrolysis with potassium ethylate. The experimental set-up consisted of a flow-injection manifold for liquid-liquid extraction without phase separation and iterative change of the flow direction that enabled: (a) filling the flow manifold with a meta periodate-acetylacetone acceptor phase; (b) sampling of small amounts (microl) from the reactor; (c) determination of free glycerol by extraction from biodiesel to the aqueous phase with simultaneous oxidation-reaction with acetylacetone in the acceptor phase; (d) continuous monitoring of the aqueous phase by passage through a photometric detector; (e) filling the flow manifold with a potassium ethylate-meta periodate-acetylacetone new acceptor phase; (d) repetition of steps b-to-d to determine total glycerol after saponification of the bound glycerol by potassium ethylate; and (f) determination of bound glycerol by difference between the second and first analyses. The results showed that the proposed automated on-line method is a suitable option in routine analysis during biodiesel production.

  9. Efficacy of home-based non-pharmacological interventions for treating depression: a systematic review and network meta-analysis of randomised controlled trials.

    PubMed

    Sukhato, Kanokporn; Lotrakul, Manote; Dellow, Alan; Ittasakul, Pichai; Thakkinstian, Ammarin; Anothaisintawee, Thunyarat

    2017-07-12

    To systematically review and compare the efficacy of all available home-based non-pharmacological treatments of depression. Systematic review and network meta-analysis of randomised controlled trials. Medline, Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were searched since inceptions to 7 August 2016. Randomised controlled trials comparing the efficacy of home-based non-pharmacological interventions with usual care of patients with depression were included in the review. Depression symptom scores and disease remission rates at the end of treatment. Seventeen studies were included in the review. Home-based non-pharmacological interventions were categorised as (1) home-based psychological intervention, (2) home-based exercise intervention, (3) combined home-based psychological intervention with exercise intervention and (4) complementary medicine. Complementary medicine approaches were excluded from the meta-analysis due to heterogeneity. The standardised mean differences of post-treatment depression symptom scores between usual care groups and home-based psychological intervention, home-based exercise intervention and combined home-based psychological intervention with exercise intervention were âˆ'0.57 (95% CI âˆ'0.84 to âˆ'0.31), âˆ'1.03 (95% CI âˆ'2.89 to 0.82) and âˆ'0.78 (95% CI âˆ'1.09 to âˆ'0.47), respectively. These results suggest that only home-based psychological intervention and combined home-based psychological intervention with exercise intervention could significantly decrease depression scores. Compared with usual care groups, the disease remission rate was also significantly higher for home-based psychological intervention (pooled risk ratio=1.53; 95% CI 1.19 to 1.98) and combined home-based psychological intervention with exercise intervention (pooled risk ratio=3.47; 95% CI 2.11 to 5.70). Of all the studied interventions, combined home-based psychological intervention with

  10. An Economic Analysis of Strategies to Control Clostridium Difficile Transmission and Infection Using an Agent-Based Simulation Model.

    PubMed

    Nelson, Richard E; Jones, Makoto; Leecaster, Molly; Samore, Matthew H; Ray, William; Huttner, Angela; Huttner, Benedikt; Khader, Karim; Stevens, Vanessa W; Gerding, Dale; Schweizer, Marin L; Rubin, Michael A

    2016-01-01

    A number of strategies exist to reduce Clostridium difficile (C. difficile) transmission. We conducted an economic evaluation of "bundling" these strategies together. We constructed an agent-based computer simulation of nosocomial C. difficile transmission and infection in a hospital setting. This model included the following components: interactions between patients and health care workers; room contamination via C. difficile shedding; C. difficile hand carriage and removal via hand hygiene; patient acquisition of C. difficile via contact with contaminated rooms or health care workers; and patient antimicrobial use. Six interventions were introduced alone and "bundled" together: (a) aggressive C. difficile testing; (b) empiric isolation and treatment of symptomatic patients; (c) improved adherence to hand hygiene and (d) contact precautions; (e) improved use of soap and water for hand hygiene; and (f) improved environmental cleaning. Our analysis compared these interventions using values representing 3 different scenarios: (1) base-case (BASE) values that reflect typical hospital practice, (2) intervention (INT) values that represent implementation of hospital-wide efforts to reduce C. diff transmission, and (3) optimal (OPT) values representing the highest expected results from strong adherence to the interventions. Cost parameters for each intervention were obtained from published literature. We performed our analyses assuming low, normal, and high C. difficile importation prevalence and transmissibility of C. difficile. INT levels of the "bundled" intervention were cost-effective at a willingness-to-pay threshold of $100,000/quality-adjusted life-year in all importation prevalence and transmissibility scenarios. OPT levels of intervention were cost-effective for normal and high importation prevalence and transmissibility scenarios. When analyzed separately, hand hygiene compliance, environmental decontamination, and empiric isolation and treatment were the

  11. New Control Design Principles Based on Measured Performance and Energy Analysis of HVAC (Heating, Ventilating, and Air-Conditioning) Systems.

    DTIC Science & Technology

    1985-01-01

    economy cycle that does not use PI con- trol. Using PI control for both the cooling coil and the economy cycle pro- duces more than a 20 percent...savings over the same system with proportional- only control. The system using PI control for both the coil and dampers cold- deck reset is the most...Furthermore, the use of PI control instead of proportional-only control has much the same beneficial impact on system energy consumption as using -. cold

  12. Climate versus carbon dioxide controls on biomass burning: a model-based analysis of the glacial-interglacial contrast

    NASA Astrophysics Data System (ADS)

    Calvo, Maria Martin; Harrison, Sandy P.; Prentice, Iain C.

    2013-04-01

    Climate controls natural fire regimes through several mechanisms, influencing the amount of fuel present, its flammability, and the probability of lightning, the chief natural ignition source. Fire prediction is challenging, even in the absence of human impacts, because of the complexity of the interactions among vegetation, fuel load and climate effects on fire incidence and spread. Reconstructions of climate, vegetation and fire for past times have already helped to improve knowledge of the controls of fire, and drawn attention to the high sensitivity of biomass burning - as registered by sedimentary charcoal records and other indicators - to temperature variations on centennial to multi-millennial time scales. In this study the Land-surface Processes and eXchanges (LPX) dynamic global vegetation model is used in an attempt to model fire and vegetation patterns during the Last Glacial Maximum (LGM), with outputs of four general circulation models (GCMs) providing LGM climate scenarios. The use of a process-based model allows quantification of changes in fluxes, and experimentation to assess the relative importance of different controls. We examined the contribution of CO2 concentration changes (responsible for large changes in vegetation productivity) between the LGM and pre-industrial Holocene to the global increase in biomass burning previously inferred from charcoal records. With both LGM climate and LGM CO2 (185 ppm) effects included, modelled biomass burning fluxes were globally lower at the LGM than in pre-industrial time, and almost consistently lower (albeit with considerable variation among the four GCMs) within each of the northern and southern tropical and extratropical bands. But combining LGM climate with pre-industrial (280 ppm) CO2 yielded qualitatively unrealistic results, with global and northern-hemisphere biomass burning fluxes even greater than in the pre-industrial climate. The artificially increased CO2 concentration increased simulated

  13. Physics based modeling of a series parallel battery pack for asymmetry analysis, predictive control and life extension

    NASA Astrophysics Data System (ADS)

    Ganesan, Nandhini; Basu, Suman; Hariharan, Krishnan S.; Kolake, Subramanya Mayya; Song, Taewon; Yeo, Taejung; Sohn, Dong Kee; Doo, Seokgwang

    2016-08-01

    Lithium-Ion batteries used for electric vehicle applications are subject to large currents and various operation conditions, making battery pack design and life extension a challenging problem. With increase in complexity, modeling and simulation can lead to insights that ensure optimal performance and life extension. In this manuscript, an electrochemical-thermal (ECT) coupled model for a 6 series × 5 parallel pack is developed for Li ion cells with NCA/C electrodes and validated against experimental data. Contribution of the cathode to overall degradation at various operating conditions is assessed. Pack asymmetry is analyzed from a design and an operational perspective. Design based asymmetry leads to a new approach of obtaining the individual cell responses of the pack from an average ECT output. Operational asymmetry is demonstrated in terms of effects of thermal gradients on cycle life, and an efficient model predictive control technique is developed. Concept of reconfigurable battery pack is studied using detailed simulations that can be used for effective monitoring and extension of battery pack life.

  14. An Economic Analysis of Strategies to Control Clostridium Difficile Transmission and Infection Using an Agent-Based Simulation Model

    PubMed Central

    Nelson, Richard E.; Jones, Makoto; Leecaster, Molly; Samore, Matthew H.; Ray, William; Huttner, Angela; Huttner, Benedikt; Khader, Karim; Stevens, Vanessa W.; Gerding, Dale; Schweizer, Marin L.; Rubin, Michael A.

    2016-01-01

    Background A number of strategies exist to reduce Clostridium difficile (C. difficile) transmission. We conducted an economic evaluation of “bundling” these strategies together. Methods We constructed an agent-based computer simulation of nosocomial C. difficile transmission and infection in a hospital setting. This model included the following components: interactions between patients and health care workers; room contamination via C. difficile shedding; C. difficile hand carriage and removal via hand hygiene; patient acquisition of C. difficile via contact with contaminated rooms or health care workers; and patient antimicrobial use. Six interventions were introduced alone and "bundled" together: (a) aggressive C. difficile testing; (b) empiric isolation and treatment of symptomatic patients; (c) improved adherence to hand hygiene and (d) contact precautions; (e) improved use of soap and water for hand hygiene; and (f) improved environmental cleaning. Our analysis compared these interventions using values representing 3 different scenarios: (1) base-case (BASE) values that reflect typical hospital practice, (2) intervention (INT) values that represent implementation of hospital-wide efforts to reduce C. diff transmission, and (3) optimal (OPT) values representing the highest expected results from strong adherence to the interventions. Cost parameters for each intervention were obtained from published literature. We performed our analyses assuming low, normal, and high C. difficile importation prevalence and transmissibility of C. difficile. Results INT levels of the “bundled” intervention were cost-effective at a willingness-to-pay threshold of $100,000/quality-adjusted life-year in all importation prevalence and transmissibility scenarios. OPT levels of intervention were cost-effective for normal and high importation prevalence and transmissibility scenarios. When analyzed separately, hand hygiene compliance, environmental decontamination, and empiric

  15. Switching from suppressive protease inhibitor-based regimens to nevirapine-based regimens: a meta-analysis of randomized controlled trials.

    PubMed

    Ena, J; Leach, A; Nguyen, P

    2008-10-01

    We performed a meta-analysis to assess the efficacy and safety of switching from protease inhibitor (PI)- to nevirapine (NVP)-based regimens in HIV-infected patients in whom virological suppression had been achieved. Six trials (550 patients) were analysed. The demographics showed that 11-48% of participants were female and 40-53% had hepatitis C or B virus infection, and the mean CD4 lymphocyte count was >500 cells/microL at study entry. NVP-based regimens showed noninferiority compared with continuation of PI therapy to maintain virological suppression in 'intention to treat' (80 vs. 78%; P=0.35) and 'on treatment' analyses (91 vs. 89%; P=0.10). Overall rates of discontinuation because of adverse events were similar in the two groups (11 vs. 10%; P=0.79). However, NVP-based therapies caused more discontinuations because of liver toxicity than PI-based therapies (7 vs. 0%; P=0.0009). At the end of follow-up there was no statistical difference in CD4, cholesterol, triglyceride and body shape measurements between the two groups. Two studies reported greater improvement in quality of life in patients who were switched to the NVP group. Switching from suppressive PI- to NVP-based regimens is virologically and immunologically safe; however, the risk of liver toxicity requires monitoring of clinical symptoms and liver chemistry during NVP therapy.

  16. Effect of an Internet-based telehealth system on functional capacity and cognition in breast cancer survivors: a secondary analysis of a randomized controlled trial.

    PubMed

    Galiano-Castillo, Noelia; Arroyo-Morales, Manuel; Lozano-Lozano, Mario; Fernández-Lao, Carolina; Martín-Martín, Lydia; Del-Moral-Ávila, Rosario; Cantarero-Villanueva, Irene

    2017-06-22

    This trial determines the effect of an Internet-based tailored exercise program compared to usual care control for improving functional capacity and cognition among breast cancer survivors. A two-arm, assessor-blinded, parallel, randomized controlled efficacy trial was conducted. Participants were recruited from the Oncology and Breast unit at the Virgen de las Nieves Hospital (Granada, Spain) between March 2012 to November 2013 and randomized to either the experimental group (an 8-week Internet-based tailored exercise program) or control group (usual care). The outcome measures were the 6-min walk test, Auditory Consonant Trigrams, and Trail Making Test. All were assessed at baseline, post-intervention, and 6-month follow-up. After intervention, the telerehabilitation group had significantly improved distances (d = 0.92, P < 0.001) as well as percentage of predicted of the 6-min walk test (d = 0.93, P < 0.001) compared with the control group. Significant improvement was also observed favoring the telerehabilitation group for the number of consonants recalled in total compared with the control group (d = 0.47, P = 0.04). These findings were maintained after 6-month follow-up (d = 0.80, P = 0.001; d = 0.76, P = 0.002; and d = 0.57, P = 0.02, respectively). Analysis was based on intention-to-treat principle. These findings support the effectiveness of a telehealth system based on an 8-week physical exercise to achieve improvements and maintain them after 6-month follow-up in terms of functional and cognitive performance in breast cancer survivors. This broad-reach modality could help the growing number of cancer survivors to face their disabling side effects.

  17. Long-term survival after traumatic brain injury: a population-based analysis controlled for nonhead trauma.

    PubMed

    Brown, Allen W; Leibson, Cynthia L; Mandrekar, Jay; Ransom, Jeanine E; Malec, James F

    2014-01-01

    To examine the contribution of co-occurring nonhead injuries to hazard of death after traumatic brain injury (TBI). A random sample of Olmsted County, Minnesota, residents with confirmed TBI from 1987 through 1999 was identified. Each case was assigned an age- and sex-matched, non-TBI "regular control" from the population. For "special cases" with accompanying nonhead injuries, 2 matched "special controls" with nonhead injuries of similar severity were assigned. Vital status was followed from baseline (ie, injury date for cases, comparable dates for controls) through 2008. Cases were compared first with regular controls and second with regular or special controls, depending on case type. In total, 1257 cases were identified (including 221 special cases). For both cases versus regular controls and cases versus regular or special controls, the hazard ratio was increased from baseline to 6 months (10.82 [2.86-40.89] and 7.13 [3.10-16.39], respectively) and from baseline through study end (2.92 [1.74-4.91] and 1.48 [1.09-2.02], respectively). Among 6-month survivors, the hazard ratio was increased for cases versus regular controls (1.43 [1.06-2.15]) but not for cases versus regular or special controls (1.05 [0.80-1.38]). Among 6-month survivors, accounting for nonhead injuries resulted in a nonsignificant effect of TBI on long-term mortality.

  18. Fuzzy logic based robotic controller

    NASA Technical Reports Server (NTRS)

    Attia, F.; Upadhyaya, M.

    1994-01-01

    Existing Proportional-Integral-Derivative (PID) robotic controllers rely on an inverse kinematic model to convert user-specified cartesian trajectory coordinates to joint variables. These joints experience friction, stiction, and gear backlash effects. Due to lack of proper linearization of these effects, modern control theory based on state space methods cannot provide adequate control for robotic systems. In the presence of loads, the dynamic behavior of robotic systems is complex and nonlinear, especially where mathematical modeling is evaluated for real-time operators. Fuzzy Logic Control is a fast emerging alternative to conventional control systems in situations where it may not be feasible to formulate an analytical model of the complex system. Fuzzy logic techniques track a user-defined trajectory without having the host computer to explicitly solve the nonlinear inverse kinematic equations. The goal is to provide a rule-based approach, which is closer to human reasoning. The approach used expresses end-point error, location of manipulator joints, and proximity to obstacles as fuzzy variables. The resulting decisions are based upon linguistic and non-numerical information. This paper presents a solution to the conventional robot controller which is independent of computationally intensive kinematic equations. Computer simulation results of this approach as obtained from software implementation are also discussed.

  19. Space construction base control system

    NASA Technical Reports Server (NTRS)

    Kaczynski, R. F.

    1979-01-01

    Several approaches for an attitude control system are studied and developed for a large space construction base that is structurally flexible. Digital simulations were obtained using the following techniques: (1) the multivariable Nyquist array method combined with closed loop pole allocation, (2) the linear quadratic regulator method. Equations for the three-axis simulation using the multilevel control method were generated and are presented. Several alternate control approaches are also described. A technique is demonstrated for obtaining the dynamic structural properties of a vehicle which is constructed of two or more submodules of known dynamic characteristics.

  20. Nonlinear Generator Control Based on Equilibrium Point Analysis for Standard One-Machine Infinite-Bus System Model

    NASA Astrophysics Data System (ADS)

    Zhang, Jian; Fujimoto, Koji; Kawamoto, Shunji

    The aim of this letter is to show that the unstable equilibrium point of the Japanese standard one-machine infinite-bus system model is eliminated by adding a simple nonlinear complementary control input to the AVR, and then the critical clearing time of the system can be more enhanced in comparison with the PSS by introducing the proposed nonlinear generator control.

  1. Orion Orbit Control Design and Analysis

    NASA Technical Reports Server (NTRS)

    Jackson, Mark; Gonzalez, Rodolfo; Sims, Christopher

    2007-01-01

    The analysis of candidate thruster configurations for the Crew Exploration Vehicle (CEV) is presented. Six candidate configurations were considered for the prime contractor baseline design. The analysis included analytical assessments of control authority, control precision, efficiency and robustness, as well as simulation assessments of control performance. The principles used in the analytic assessments of controllability, robustness and fuel performance are covered and results provided for the configurations assessed. Simulation analysis was conducted using a pulse width modulated, 6 DOF reaction system control law with a simplex-based thruster selection algorithm. Control laws were automatically derived from hardware configuration parameters including thruster locations, directions, magnitude and specific impulse, as well as vehicle mass properties. This parameterized controller allowed rapid assessment of multiple candidate layouts. Simulation results are presented for final phase rendezvous and docking, as well as low lunar orbit attitude hold. Finally, on-going analysis to consider alternate Service Module designs and to assess the pilot-ability of the baseline design are discussed to provide a status of orbit control design work to date.

  2. Association between Interleukin-8-251A/T polymorphism and gastric cancer susceptibility: a meta-analysis based on 5286 cases and 8000 controls.

    PubMed

    Zhang, Yafei; Zeng, Xianling; Lu, Hongwei; Li, Yiming; Ji, Hong

    2015-01-01

    Published data on the association between Interleukin-8-251A/T polymorphism and gastric cancer (GC) risk are inconclusive. Thus, we conducted a meta-analysis to evaluate the relationship between cyclin D1 G870A polymorphism and GC risk. We searched PubMed, EMBASE, Web of science and the Cochrane Library up to July 12, 2015 for relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of associations. Twenty-six studies published from 2004 to 2015, with a total of 5286 cases and 8000 controls, were included in this meta-analysis. The pooled results showed that there was significant association between Interleukin-8-251A/T polymorphism and GC risk in any genetic model. In the subgroup analysis by ethnicity, the effects remained in Asians. However, no genetic models reached statistical association in Europeans. The subgroup analysis stratified by Source of controls showed an increased breast cancer risk in hospital-based (HB) studies in any genetic model except recessive model. However, there was no association in any genetic model in population based (PB) studies. When stratifying by Genotyping method, we found statistical association in Non-RFLP (restriction fragment length polymorphism) in any genetic model except heterozygote comparison, the effect was remain in PCR-RFLP in dominant model and heterozygote comparison. This meta-analysis suggests that Interleukin-8-251A/T polymorphism is a risk factor for susceptibility to GC in overall population, especially in Asians, in hospital populations and in Non-RFLP. While, there was no association in Europeans and in general population. Further large scale multicenter epidemiological studies are warranted to confirm this finding.

  3. Viking orbiter attitude control analysis

    NASA Technical Reports Server (NTRS)

    Rodriguez, G.

    1977-01-01

    Two Viking orbiters are currently in Mars orbit. In the nearly two years since they were launched, the orbiters have successfully performed many functions including transportation of the Viking landers to Mars. The orbiters have for the last year provided relay links for lander-earth communications, and they have carried out from orbit their own scientific exploration of the planet. Crucial to the success of the orbiters has been the performance of the on-board attitude control system, which has provided the required orbiter stabilization and orientation throughout the missions. A comprehensive spacecraft and attitude control system dynamic analysis was necessary to certify the control system before launch and to evaluate its flight performance. This paper contains an outline of the analysis and of some of its results.

  4. Map-based cloning and functional analysis of YGL8, which controls leaf colour in rice (Oryza sativa).

    PubMed

    Zhu, Xiaoyan; Guo, Shuang; Wang, Zhongwei; Du, Qing; Xing, Yadi; Zhang, Tianquan; Shen, Wenqiang; Sang, Xianchun; Ling, Yinghua; He, Guanghua

    2016-06-13

    As the indispensable part of plant, leaf blade mainly functions as the production workshops where organic substance is produced by photosynthesis. Leaf colour mutation is a genetic phenomenon that has a high frequency and is easily identified. The mutations always exhibit negative impact on the development of plants in any of the different stages of growth. Up to now, numerous genes involved in leaf colour mutations have been cloned. In this study, a yellow-green leaf mutant, yellow-green leaf 8 (ygl8), with stable genetic phenotype, has been screened out in the progeny of an excellent indica restorer line Jinhui 10 with seeds treated by EMS. The levels of Chl a, Chl b and total chlorophyll were significantly lower in ygl8 than those in the WT throughout the whole growth period, while no clear change was noted in the Chl a/b ratio. Transmission electron microscopy demonstrated that the lamellae were clearly intumescent and intricately stacked in ygl8. Furthermore, compared with those of the WT, the stomatal conductance, intercellular CO2 concentration, photosynthetic rate and transpiration rate of ylg8 were all significantly lower. Map-based cloning results showed that Loc_Os01g73450, encoding a chloroplast-targeted UMP kinase, corresponded to Ygl8 and played an important role in regulating leaf colour in rice (Oryza sativa). Complementation of ygl8 with the WT DNA sequence of Loc_Os01g73450 led to restoration of the normal phenotype, and transgenic RNA interference plants showed a yellow-green colour. Analysis of the spatial and temporal expression of Ygl8 indicated that it was highly expressed in leaf blades and weakly expressed in other tissues. qRT-PCR also showed that the expression levels of the major Photosystem I core subunits plastome-encoded PsaA, PsaB and PsbC were significantly reduced in ygl8. The expression levels of nuclear-encoded gene involved in Chl biosynthesis HEMC, HEME, and PORA were also decreased when compared with the wild-type. Independent

  5. The Asthma Control Test, Japanese version (ACT-J) as a predictor of Global Initiative for Asthma (GINA) guideline-defined asthma control: analysis of a questionnaire-based survey.

    PubMed

    Hasegawa, Takashi; Koya, Toshiyuki; Sakagami, Takuro; Kagamu, Hiroshi; Arakawa, Masaaki; Gejyo, Fumitake; Narita, Ichiei; Suzuki, Eiichi

    2013-09-01

    The 2006 Global Initiative for Asthma (GINA 2006) guidelines emphasize the importance of evaluating the control rather than the severity of asthma. The Asthma Control Test (ACT) is well known to be an excellent tool for evaluating asthma control in the clinical setting. This study aimed to evaluate the ACT, Japanese version (ACT-J) as a predictor of asthma control as defined by the GINA 2006 guidelines in actual clinical practice. A cross-sectional analysis comparing the ACT-J score and GINA classification of asthma control among 419 patients of primary care physicians and specialists was performed using the data from a 2010 questionnaire-based survey conducted by the Niigata Asthma Treatment Study Group. The optimal cut-off point of the ACT-J score for predicting GINA-defined asthma control was 23, with ACT-J scores of ≥23 and ≤22 predicting controlled and uncontrolled asthma with area under the receiver operating characteristics curve values of 0.76 [95% confidence interval (CI): 0.72-0.81] and 0.93 [95% CI: 0.90-0.97], respectively. ACT scores of ≥23 and ≤22 are useful for identifying patients with controlled and uncontrolled asthma, respectively, as defined by GINA 2006, and the latter is more strongly predictive than the former. The reason for the higher cut-off point of the ACT-J relative to other versions of the ACT is unclear and warrants further investigation.

  6. Effect of flexible sigmoidoscopy-based screening on incidence and mortality of colorectal cancer: a systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Elmunzer, B Joseph; Hayward, Rodney A; Schoenfeld, Philip S; Saini, Sameer D; Deshpande, Amar; Waljee, Akbar K

    2012-01-01

    Randomized controlled trials (RCTs) have yielded varying estimates of the benefit of flexible sigmoidoscopy (FS) screening for colorectal cancer (CRC). Our objective was to more precisely estimate the effect of FS-based screening on the incidence and mortality of CRC by performing a meta-analysis of published RCTs. Medline and Embase databases were searched for eligible articles published between 1966 and 28 May 2012. After screening 3,319 citations and 29 potentially relevant articles, two reviewers identified five RCTs evaluating the effect of FS screening on the incidence and mortality of CRC. The reviewers independently extracted relevant data; discrepancies were resolved by consensus. The quality of included studies was assessed using criteria set out by the Evidence-Based Gastroenterology Steering Group. Random effects meta-analysis was performed. The five RCTs meeting eligibility criteria were determined to be of high methodologic quality and enrolled 416,159 total subjects. Four European studies compared FS to no screening and one study from the United States compared FS to usual care. By intention to treat analysis, FS-based screening was associated with an 18% relative risk reduction in the incidence of CRC (0.82, 95% CI 0.73-0.91, p<0.001, number needed to screen [NNS] to prevent one case of CRC = 361), a 33% reduction in the incidence of left-sided CRC (RR 0.67, 95% CI 0.59-0.76, p<0.001, NNS = 332), and a 28% reduction in the mortality of CRC (relative risk [RR] 0.72, 95% CI 0.65-0.80, p<0.001, NNS = 850). The efficacy estimate, the amount of benefit for those who actually adhered to the recommended treatment, suggested that FS screening reduced CRC incidence by 32% (p<0.001), and CRC-related mortality by 50% (p<0.001). Limitations of this meta-analysis include heterogeneity in the design of the included trials, absence of studies from Africa, Asia, or South America, and lack of studies comparing FS with colonoscopy or stool-based testing. This meta-analysis

  7. Model-Based Safety Analysis

    NASA Technical Reports Server (NTRS)

    Joshi, Anjali; Heimdahl, Mats P. E.; Miller, Steven P.; Whalen, Mike W.

    2006-01-01

    System safety analysis techniques are well established and are used extensively during the design of safety-critical systems. Despite this, most of the techniques are highly subjective and dependent on the skill of the practitioner. Since these analyses are usually based on an informal system model, it is unlikely that they will be complete, consistent, and error free. In fact, the lack of precise models of the system architecture and its failure modes often forces the safety analysts to devote much of their effort to gathering architectural details about the system behavior from several sources and embedding this information in the safety artifacts such as the fault trees. This report describes Model-Based Safety Analysis, an approach in which the system and safety engineers share a common system model created using a model-based development process. By extending the system model with a fault model as well as relevant portions of the physical system to be controlled, automated support can be provided for much of the safety analysis. We believe that by using a common model for both system and safety engineering and automating parts of the safety analysis, we can both reduce the cost and improve the quality of the safety analysis. Here we present our vision of model-based safety analysis and discuss the advantages and challenges in making this approach practical.

  8. Control of the Double-linked Trident Snake Robot Based on the Analysis of Its Oscillatory Dynamics

    NASA Astrophysics Data System (ADS)

    Ishikawa, Masato; Fujino, Takahiro

    This paper is concerned with a new approach to the locomotion control of the trident snake robot, focusing on its double-linked case where the robot is composed of a triangular body and three branches of double-linked snake-like legs. Originally, this robot was proposed by the authors as a novel example of nonholonomic mobile robot. The well-known Lie Algebra Rank Condition (LARC) for its nonlinear controllability has an odd structure that it contains two generator vector-fields and higher order Lie brackets, which makes its control problem extremely challenging. In this paper, for this difficult control problem, we first propose a design algorithm which partially achieves the desired locomotion. Then we point out that the resulting motion may or may not be a stable limit cycle, depending on the eigenvalues of the corresponding discrete-time dynamics on its Poincaré map. Finally, we propose a full controller design by combining the stable limit cycles. The validity of the proposed idea is examined by numerical simulations.

  9. Systematic Review and Meta-analysis of the Impact of Chemical-Based Mollusciciding for Control of Schistosoma mansoni and S. haematobium Transmission

    PubMed Central

    King, Charles H.; Sutherland, Laura J.; Bertsch, David

    2015-01-01

    Background Programs for schistosomiasis control are advancing worldwide, with many benefits noted in terms of disease reduction. Yet risk of reinfection and recurrent disease remain, even in areas with high treatment coverage. In the search for means to better prevent new Schistosoma infections, attention has returned to an older strategy for transmission control, i.e., chemical mollusciciding, to suppress intermediate host snail species responsible for S. mansoni and S. haematobium transmission. The objective of this systematic review and meta-analysis was to summarize prior experience in molluscicide-based control of Bulinus and Biomphalaria spp. snails, and estimate its impact on local human Schistosoma infection. Methodology/Principal Findings The review was registered at inception with PROSPERO (CRD42013006869). Studies were identified by online database searches and hand searches of private archives. Eligible studies included published or unpublished mollusciciding field trials performed before January 2014 involving host snails for S. mansoni or S. haematobium, with a primary focus on the use of niclosamide. Among 63 included papers, there was large variability in terms of molluscicide dosing, and treatment intervals varied from 3–52 weeks depending on location, water source, and type of application. Among 35 studies reporting on prevalence, random effects meta-analysis indicated that, on average, odds of infection were reduced 77% (OR 0.23, CI95% 0.17, 0.31) during the course of mollusciciding, with increased impact if combined with drug therapy, and progressively greater impact over time. In 17 studies reporting local incidence, risk of new infection was reduced 64% (RR 0.36 CI95% 0.25, 0.5), but additional drug treatment did not appear to influence incidence effects. Conclusion/Significance While there are hurdles to implementing molluscicide control, its impact on local transmission is typically strong, albeit incomplete. Based on past experience

  10. Systematic Review and Meta-analysis of the Impact of Chemical-Based Mollusciciding for Control of Schistosoma mansoni and S. haematobium Transmission.

    PubMed

    King, Charles H; Sutherland, Laura J; Bertsch, David

    2015-12-01

    Programs for schistosomiasis control are advancing worldwide, with many benefits noted in terms of disease reduction. Yet risk of reinfection and recurrent disease remain, even in areas with high treatment coverage. In the search for means to better prevent new Schistosoma infections, attention has returned to an older strategy for transmission control, i.e., chemical mollusciciding, to suppress intermediate host snail species responsible for S. mansoni and S. haematobium transmission. The objective of this systematic review and meta-analysis was to summarize prior experience in molluscicide-based control of Bulinus and Biomphalaria spp. snails, and estimate its impact on local human Schistosoma infection. The review was registered at inception with PROSPERO (CRD42013006869). Studies were identified by online database searches and hand searches of private archives. Eligible studies included published or unpublished mollusciciding field trials performed before January 2014 involving host snails for S. mansoni or S. haematobium, with a primary focus on the use of niclosamide. Among 63 included papers, there was large variability in terms of molluscicide dosing, and treatment intervals varied from 3-52 weeks depending on location, water source, and type of application. Among 35 studies reporting on prevalence, random effects meta-analysis indicated that, on average, odds of infection were reduced 77% (OR 0.23, CI95% 0.17, 0.31) during the course of mollusciciding, with increased impact if combined with drug therapy, and progressively greater impact over time. In 17 studies reporting local incidence, risk of new infection was reduced 64% (RR 0.36 CI95% 0.25, 0.5), but additional drug treatment did not appear to influence incidence effects. While there are hurdles to implementing molluscicide control, its impact on local transmission is typically strong, albeit incomplete. Based on past experience, regular focal mollusciciding is likely to contribute significantly to

  11. Effects of calcium channel blocker benidipine-based combination therapy on target blood pressure control and cardiovascular outcome: a sub-analysis of the COPE trial.

    PubMed

    Umemoto, Seiji; Ogihara, Toshio; Matsuzaki, Masunori; Rakugi, Hiromi; Ohashi, Yasuo; Saruta, Takao

    2017-04-01

    We compared three benidipine-based regimens-that is, benidipine plus angiotensin receptor blocker (ARB), β-blocker (BB) or thiazide-and found that the benidipine-BB combination was less beneficial in reducing the risk of stroke than the benidipine-thiazide combination. This sub-analysis sought to compare the effects of reaching a target blood pressure (BP) (<140/90 mm Hg) on the cardiovascular outcomes among the three benidipine-based treatment groups in the Combination Therapy of Hypertension to Prevent Cardiovascular Events trial. This sub-analysis included 3001 subjects to evaluate the achievement of target BP at a minimum of three points at 6-month intervals of clinical BP measurements during the study period. After randomization, the patients were categorized into two groups on the basis of achieved on-treatment target BP: a good control (GC) group achieving a BP⩾66.7% of the target and a poor control (PC) group with a BP <66.6% of the target. For each of the two control groups, outcomes were compared among the three treatment groups. The event rates for cardiovascular composite endpoints, stroke and hard cardiovascular events were higher in the PC group than the GC group (P=0.041, P=0.042 and P=0.038, respectively). Within the PC group, hazard ratios for the incidence of cardiovascular events were lower in the benidipine-thiazide group than in the benidipine-BB group (composite cardiovascular events: 2.04, P=0.033; stroke: 4.14, P=0.005; and hard cardiovascular events: 3.52, P=0.009). Within the GC group, the incidence of cardiovascular events was not different among the three treatment regimens. The benidipine-thiazide combination may provide better cardiovascular outcomes than the benidipine-BB combination even in patients with poor BP control.

  12. 78 FR 3646 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND....110--Natural or Unavoidable Defects in Food for Human Use That Present No Health Hazard (Proposed Sec... the Centers for Disease Control and Prevention (CDC). This is a significant public health burden that...

  13. 78 FR 48636 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Parts 1, 16, 106, 110, 114, 117, 120, 123, 129, 179... Preventive Controls for Human Food; Extension of Comment Periods AGENCY: Food and Drug Administration, HHS... collection provisions. SUMMARY: The Food and Drug Administration (FDA or we) is extending the comment period...

  14. Three genetic polymorphisms of homocysteine-metabolizing enzymes and risk of coronary heart disease: a meta-analysis based on 23 case-control studies.

    PubMed

    Chen, Ling; Liu, Liu; Hong, Kui; Hu, Jianxin; Cheng, Xiaoshu

    2012-02-01

    Many epidemiological studies have explored the relationships between three genetic polymorphisms of genes encoding homocysteine-metabolizing enzymes (methionine synthase [MTR] A2756G, methionine synthase reductase [MTRR] A66G, and N(5),N(10)-methylenetetrahydrofolate reductase [MTHFR] A1298C) and risk of coronary heart disease (CHD), but no conclusive results were obtained. Therefore, we performed a meta-analysis of 23 case-control studies. Odds ratio (OR) and 95% confidence interval (95% CI) were used to examine the strength of the associations. Among those primary studies, 22 studies were for Europeans, and one study focused on the MTR A2756G polymorphism in Asians. The results of combined analyses of the MTR A2756G polymorphism suggested that the G allele was associated with increased risk of CHD and myocardial infarction (MI) especially for Europeans (GG vs. AA for CHD: OR [95% CI]=1.63 [1.18-2.25], p(z)(-test)=0.001, p(heterogeneity)=0.274; GG+AG vs. AA for MI: OR [95% CI]=1.44 [1.08-1.93], p(z)(-test)=0.014, p(heterogeneity)=0.611). In addition, the G allele was also associated with higher risk CHD based on population-based case-control studies (PCC) (GG vs. AA: OR [95% CI]=1.75 [1.24-2.49], p(z)(-test)=0.002, p(heterogeneity)=0.316). The results suggested that the MTRR A66G polymorphism was not associated with risk of CHD for Europeans (AA vs. GG: OR [95% CI]=1.07 [0.59-1.94], p(z)(-test)=0.831, p(heterogeneity)<0.01). The results suggested that the C allele of the MTHFR A1298C polymorphism might be associated with the increased risk of MI for Europeans (CC vs. CA+AA: OR [95% CI]=1.37 [1.03-1.84], p(z)(-test)=0.033, p(heterogeneity)=0.668). However, when subgroup analyses for sources of controls were performed, conflicting results were obtained. The results suggested that the C allele was associated with decreased risk of CHD based on hospital-based case-control studies, but associated with increased risk of CHD based on PCC. This meta-analysis suggests that

  15. Response surface modeling-based source contribution analysis and VOC emission control policy assessment in a typical ozone-polluted urban Shunde, China.

    PubMed

    You, Zhiqiang; Zhu, Yun; Jang, Carey; Wang, Shuxiao; Gao, Jian; Lin, Che-Jen; Li, Minhui; Zhu, Zhenghua; Wei, Hao; Yang, Wenwei

    2017-01-01

    To develop a sound ozone (O3) pollution control strategy, it is important to well understand and characterize the source contribution due to the complex chemical and physical formation processes of O3. Using the "Shunde" city as a pilot summer case study, we apply an innovative response surface modeling (RSM) methodology based on the Community Multi-Scale Air Quality (CMAQ) modeling simulations to identify the O3 regime and provide dynamic analysis of the precursor contributions to effectively assess the O3 impacts of volatile organic compound (VOC) control strategy. Our results show that Shunde is a typical VOC-limited urban O3 polluted city. The "Jiangmen" city, as the main upper wind area during July 2014, its VOCs and nitrogen oxides (NOx) emissions make up the largest contribution (9.06%). On the contrary, the contribution from local (Shunde) emission is lowest (6.35%) among the seven neighbor regions. The local VOCs industrial source emission has the largest contribution comparing to other precursor emission sectors in Shunde. The results of dynamic source contribution analysis further show that the local NOx control could slightly increase the ground O3 under low (10.00%) and medium (40.00%) reduction ratios, while it could start to turn positive to decrease ground O3 under the high NOx abatement ratio (75.00%). The real-time assessment of O3 impacts from VOCs control strategies in Pearl River Delta (PRD) shows that the joint regional VOCs emission control policy will effectively reduce the ground O3 concentration in Shunde.

  16. Model-based analysis of environmental controls over ecosystem primary production in an alpine tundra dry meadow

    SciTech Connect

    Fan, Zhaosheng; Neff, Jason C.; Wieder, William R.

    2016-02-10

    We investigated several key limiting factors that control alpine tundra productivity by developing an ecosystem biogeochemistry model. The model simulates the coupled cycling of carbon (C), nitrogen (N), and phosphorus (P) and their interactions with gross primary production (GPP). It was parameterized with field observations from an alpine dry meadow ecosystem using a global optimization strategy to estimate the unknown parameters. The model, along with the estimated parameters, was first validated against independent data and then used to examine the environmental controls over plant productivity. Our results show that air temperature is the strongest limiting factor to GPP in the early growing season, N availability becomes important during the middle portion of the growing season, and soil moisture is the strongest limiting factors by late in the growing season. Overall, the controls over GPP during the growing season, from strongest to weakest, are soil moisture content, air temperature, N availability, and P availability. This simulation provides testable predictions of the shifting nature of physical and nutrient limitations on plant growth. The model also indicates that changing environmental conditions in the alpine will likely lead to changes in productivity. For example, warming eliminates the control of P availability on GPP and makes N availability surpass air temperature to become the second strongest limiting factor. In contrast, an increase in atmospheric nutrient deposition eliminates the control of N availability and enhances the importance of P availability. Furthermore, these analyses provide a quantitative and conceptual framework that can be used to test predictions and refine ecological analyses at this long-term ecological research site.

  17. Model-based analysis of environmental controls over ecosystem primary production in an alpine tundra dry meadow

    DOE PAGES

    Fan, Zhaosheng; Neff, Jason C.; Wieder, William R.

    2016-02-10

    We investigated several key limiting factors that control alpine tundra productivity by developing an ecosystem biogeochemistry model. The model simulates the coupled cycling of carbon (C), nitrogen (N), and phosphorus (P) and their interactions with gross primary production (GPP). It was parameterized with field observations from an alpine dry meadow ecosystem using a global optimization strategy to estimate the unknown parameters. The model, along with the estimated parameters, was first validated against independent data and then used to examine the environmental controls over plant productivity. Our results show that air temperature is the strongest limiting factor to GPP in themore » early growing season, N availability becomes important during the middle portion of the growing season, and soil moisture is the strongest limiting factors by late in the growing season. Overall, the controls over GPP during the growing season, from strongest to weakest, are soil moisture content, air temperature, N availability, and P availability. This simulation provides testable predictions of the shifting nature of physical and nutrient limitations on plant growth. The model also indicates that changing environmental conditions in the alpine will likely lead to changes in productivity. For example, warming eliminates the control of P availability on GPP and makes N availability surpass air temperature to become the second strongest limiting factor. In contrast, an increase in atmospheric nutrient deposition eliminates the control of N availability and enhances the importance of P availability. Furthermore, these analyses provide a quantitative and conceptual framework that can be used to test predictions and refine ecological analyses at this long-term ecological research site.« less

  18. Comparative analysis of two different alar base sutures after Le Fort I osteotomy: randomized double-blind controlled trial.

    PubMed

    Ritto, Fabio G; Medeiros, Paulo José; de Moraes, Márcio; Ribeiro, Danilo Passeado Branco

    2011-02-01

    The aim of this prospective study was to analyze the efficacy of a new alar base cinch suture by comparing it with the commonly used cinch suture described by Schendel and Delaire in Dr. William Bell's book. Thirty-five patients submitted to maxillary impaction and/or advancements of ≥ 3 mm were randomly divided into 2 groups. Group 1 received an extra oral alar base cinch suture, and patients from group 2 received the classic intraoral suture. Alar and alar base width were measured before and after surgery in digital photographs, with the patient's head in a submental oblique view. Data were reported as means and standard deviations, and difference between groups were determined using Welch t test. A P value of <.05 was considered to be statistically significant. Mean alar base widening was 1.38 mm in group 1 and 2.5 mm in group 2, and mean alar widening was 1.40 mm in group 1 and 2.31 mm in group 2. The difference was statistically significant (P < .05). Extraoral alar base cinch suture was more effective in maintaining preoperative Alar and alar base width compared with classic intraoral nasal suture. Copyright © 2011 Mosby, Inc. All rights reserved.

  19. Influence of a home-based exercise program on the urine pH in elderly female subjects: a secondary analysis of a randomized controlled trial.

    PubMed

    Nishida, Yuichiro; Tanaka, Keitaro; Hara, Megumi; Hirao, Noriko; Tanaka, Hiroaki; Tobina, Takuro; Ikeda, Masaharu; Yamato, Hiroshi; Ohta, Masanori

    2017-01-01

    A low urine pH is a characteristic metabolic feature of metabolic syndrome and type 2 diabetes. The purpose of the current study was to investigate the effects of a 12-week home-based bench step exercise on the urine pH status of elderly female subjects. The current study is a secondary analysis of a randomized controlled trial (RCT) in which 59 postmenopausal female subjects were randomized to either the exercise group (n = 29) or the control group (n = 30). The subjects in the exercise group were instructed to perform home-based exercises using a bench step at the anaerobic threshold (AT), with a goal of performing ≥140 min/week at home for 12 weeks. The subjects in the control group were instructed to not change their normal lifestyle. Urine was collected after overnight fasting, and the urine pH was measured using a urinary test strip. The inter-group-differences at baseline and the pre-post changes within groups were assessed using the Mann-Whitney U test and Wilcoxon's signed-rank test, respectively. Additionally, the difference in the post-intervention urine pH levels of the two groups, adjusted for the pre-intervention values (the estimated effect size) and the precision (95% confidence intervals) were investigated using an analysis of covariance. The pre-post comparison of the urine pH data using Wilcoxon's signed-rank test showed a significant increase in the urine pH levels of the exercise group (p < 0.05); there was no significant change in the urine pH levels of the control group. However, the estimated effect size (0.15) was small and the confidence interval straddled 0 (-0.25-0.55). Based on the results of the current secondary analysis of an RCT, we could not clearly conclude that exercise has a beneficial effect on the urine pH. Further well-designed RCTs should be conducted to determine whether aerobic exercise is truly able to ameliorate urine acidification. The study was retrospectively registered in the University Hospital

  20. Play-based interventions improve physical function for people with adult-acquired brain injury: a systematic review and meta-analysis of randomised controlled trials.

    PubMed

    Saywell, Nicola; Taylor, Nick; Rodgers, Emma; Skinner, Luke; Boocock, Mark

    2017-02-01

    To undertake a systematic review and meta-analysis of the effectiveness of play-based interventions compared to traditional therapy in rehabilitation of adults with adult-acquired brain injury. The search was performed using Medline; Cinahl Plus; Health Source (Nursing/Academic Edition); Psychology and behavioural sciences collection; Biomedical reference collection (basic). Studies included were randomised controlled trials that investigated the effect of play-based interventions on physical function of adults with adult acquired brain injury. Two independent reviewers identified eligible studies and assessed methodological quality using a modified Downs and Black. Meta-analysis compared standardised differences in means, to determine effect sizes for grouped functional outcome measures. The GRADE scoring system was used to determine the level of clinical evidence. Thirty studies met the inclusion criteria, 13 were considered high quality and 17 moderate quality. Studies predominantly involved post-stroke participants, with only three studies including participants with traumatic brain injury. When compared to traditional therapy, dose-matched studies of play-based interventions showed a significant effect on independence (Effect size (ES) = 0.6) and physical performance (ES = 0.43), as measured using the Fugl -Meyer. For non-dose matched studies, play-based interventions showed a significant improvement for balance (ES = 0.76) compared with traditional therapy. In all studies that measured participant enjoyment, play-based therapy was rated as more enjoyable than traditional therapy. Play-based interventions for people with adult acquired brain injury are more effective in improving balance and independence, which may be due to them being more enjoyable than traditional therapy.

  1. TDRSS operations control analysis study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The use of an operational Tracking and Data Relay Satellite System (TDRSS) and the remaining ground stations for the STDN (GSTDN) was investigated. The operational aspects of TDRSS concepts, GSTDN as a 14-site network, and GSTDN as a 7 site-network were compared and operations control concepts for the configurations developed. Man/machine interface, scheduling system, and hardware/software tradeoff analyses were among the factors considered in the analysis.

  2. [Analysis and Control of in Vivo Kinetics of Exosomes for the Development of Exosome-based DDS].

    PubMed

    Takahashi, Yuki; Nishikawa, Makiya; Takakura, Yoshinobu

    2016-01-01

      Exosomes are secretory membrane vesicles containing lipids, proteins, and nucleic acids. They act as intercellular transporters by delivering their components to exosome recipient cells. Based on their endogenous delivery system properties, exosomes are expected to become drug delivery systems (DDS) for various molecules such as nucleic acid-based drugs. Important factors such as drug loading to exosomes, production, and pharmacokinetics of exosomes need to be considered for the development of exosome-based DDS. Of these, the pharmacokinetics of exosomes have rarely been studied, probably because of the lack of quantitative evaluation methods of in vivo exosomal pharmacokinetics. We selected lactadherin as an exosome tropic protein and developed it as a fusion protein with Gaussia luciferase to label exosomes for in vivo imaging. In addition, a fusion protein of lactadherin and streptavidin was developed, and the tissue distribution of exosomes was quantitatively evaluated by radiolabeling the exosomes using (125)I-labeled biotin. Using labeled exosomes, we found that intravenously injected exosomes were rapidly cleared from the systemic circulation by macrophages. In addition, the exosomes were mainly distributed to the liver, lung, and spleen. We also examined the effect of exosome isolation methods on their physicochemical and pharmacokinetic properties. We found that exosomes collected by the ultracentrifugation-based density-gradient method were more dispersed than exosomes collected by other methods, including the ultracentrifugation-based pelleting method. The gradient method is more time-consuming than others; therefore the development of a more efficient method for exosome isolation will advance the development of exosome-based DDS.

  3. Impact of combined vector-control and vaccination strategies on transmission dynamics of dengue fever: a model-based analysis.

    PubMed

    Knerer, Gerhart; Currie, Christine S M; Brailsford, Sally C

    2015-06-01

    Dengue fever is a vector-borne disease prevalent in tropical and subtropical regions. It is an important public health problem with a considerable and often under-valued disease burden in terms of frequency, cost and quality-of-life. Recent literature reviews have documented the development of mathematical models of dengue fever both to identify important characteristics for future model development as well as to assess the impact of dengue control interventions. Such reviews highlight the importance of short-term cross-protection; antibody-dependent enhancement; and seasonality (in terms of both favourable and unfavourable conditions for mosquitoes). The compartmental model extends work by Bartley (2002) and combines the following factors: seasonality, age-structure, consecutive infection by all four serotypes, cross-protection and immune enhancement, as well as combined vector-host transmission. The model is used to represent dengue transmission dynamics using parameters appropriate for Thailand and to assess the potential impact of combined vector-control and vaccination strategies including routine and catch-up vaccination strategies on disease dynamics. When seasonality and temporary cross-protection between serotypes are included, the model is able to approximate the observed incidence of dengue fever in Thailand. We find vaccination to be the most effective single intervention, albeit with imperfect efficacy (30.2 %) and limited duration of protection. However, in combination, control interventions and vaccination exhibit a marked impact on dengue fever transmission. This study shows that an imperfect vaccine can be a useful weapon in reducing disease spread within the community, although it will be most effective when promoted as one of several strategies for combating dengue fever transmission.

  4. Target-controlled inhalation anaesthesia: A cost-benefit analysis based on the cost per minute of anaesthesia by inhalation.

    PubMed

    Ponsonnard, Sébastien; Galy, Antoine; Cros, Jérôme; Daragon, Armelle Marie; Nathan, Nathalie

    2017-02-01

    End-tidal target-controlled inhalational anaesthesia (TCIA) with halogenated agents (HA) provides a faster and more accurately titrated anaesthesia as compared to manually-controlled anaesthesia. This study aimed to measure the macro-economic cost-benefit ratio of TCIA as compared to manually-controlled anaesthesia. This retrospective and descriptive study compared direct drug spending between two hospitals before 2011 and then after the replacement of three of six anaesthesia machines with TCIA mode machines in 2012 (Aisys carestation(®), GE). The direct costs were obtained from the pharmacy department and the number and duration of the anaesthesia procedures from the computerized files of the hospital. The cost of halogenated agents was reduced in the hospital equipped with an Aisys carestation(®) by 13% as was the cost of one minute of anaesthesia by inhalation (€0.138 and €0.121/min between 2011 and 2012). The extra cost of the implementation of the 3 anaesthesia machines could be paid off with the resulting savings over 6 years. TCIA appears to have a favourable cost-benefit ratio. Despite a number of factors, which would tend to minimise the saving and increase costs, we still managed to observe a 13% savings. Shorter duration of surgery, type of induction as well as the way HA concentration is targeted may influence the savings results obtained. Copyright © 2016 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

  5. Analysis of relay based valley coil system of K-130 Cyclotron and an approach to computer controlled system

    NASA Astrophysics Data System (ADS)

    Shoor, B.

    2016-09-01

    To overcome the first harmonic field imperfection in sector focused cyclotron, a set of coils placed in valleys are used to produce an opposite first harmonic effect. Usually, at the time of beam tuning the phase of the first harmonic is varied using a relay system. It can be shown analytically that magnitude of it changes simultaneously, when phase is changed. This is not desirable at the time of beam tuning. Moreover phase changes in long steps, which hampers accuracy of beam tuning. To overcome this, a computer controlled system is suggested where amplitude remains constant at the time of phase change. Moreover, phase can be changed continuously which gives better tuning accuracy.

  6. The MPO−463G>A Polymorphism and Lung Cancer Risk: A Meta-Analysis Based on 22 Case–Control Studies

    PubMed Central

    Yang, Lei; Ren, Li; Zhou, Fu-Xiang; Hu, Liu; He, Wei; Li, Bai-Yu; Zhu, Yan; Jiang, Huan-Gang; Zhou, Yun-Feng

    2013-01-01

    Background Myeloperoxidase (MPO) is an endogenous oxidant enzyme that produces reactive oxygen species (ROS) and may be involved in lung carcinogenesis. The MPO−463G>A polymorphism influences MPO transcription and has been associated with lung cancer susceptibility. However, the association between the MPO−463G>A polymorphism and lung cancer risk remains controversial. Method To investigate the effect of this polymorphism on lung cancer susceptibility, we performed a meta-analysis based on 22 published case–control studies including 7,520 patients with lung cancer and 8,600 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. Results Overall, there was no evidence for significant association between MPO−463G>A polymorphism and lung cancer susceptibility (for AA versus GG: OR = 0.91, 95%CI = 0.67–1.24; for GA versus GG: OR = 0.87, 95% CI = 0.78–0.98; for AA/GA versus GG: OR = 0.90, 95% CI = 0.80–1.01; for AA versus GA/GG: OR = 0.96, 95% CI = 0.72–1.28). In the stratified analyses by ethnicity, source of controls and smoking status, we also did not find any significant association between them. Conclusions In summary, this meta-analysis suggests MPO−463G>A polymorphism may not be a risk factor for developing lung cancer. However, further prospective well-designed population-based studies with larger sample size are expected to validate the results. PMID:23840365

  7. Meta-analysis of the association between the HNF1B rs4430796 (A>G) polymorphism and risk of prostate cancer based on case-control studies.

    PubMed

    Zhao, Y; Liang, J; Qi, J G; Yang, N; Wu, G; Lin, Y L; Cao, J Y; Wang, Q; Wang, Q C

    2015-07-03

    Genome-wide studies have reported an association between the HNF1B rs4430796 (A>G) polymorphism and prostate cancer risk, but results have been inconsistent and recent meta-analyses have been inadequate. This study aimed to integrate previous results and explore the validity of this association. Electronic searches for all relevant publications through May 18, 2014, were conducted across several databases. Additional studies were identified manually, and only the most recent or complete were used in this meta-analysis. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. Seven eligible case-control studies were identified, incorporating a total of 14,049 patients and 12,674 controls. Overall, we found that the rs4430796 (A>G) polymorphism had a decreased risk of prostate cancer (GG vs AA: OR = 0.661, 95%CI = 0.615-0.710, P = 0.304; AG vs AA: OR = 0.782, 95%CI = 0.739-0.828, P = 0.435; dominant model: OR = 0.743, 95%CI = 0.704-0.784, P = 0.912; recessive model: OR = 0.764, 95%CI = 0.718-0.813, P = 0.01). Furthermore, in the stratified analysis, there were significantly decreased risks among studies with population- and hospital-based controls. In the subgroup analysis by ethnicity, significantly decreased risks were also found among Caucasians, Americans, and Asians. Our results suggested that the HNF1B rs4430796 (A>G) polymorphism decreased the risk of prostate cancer. In the future, additional and larger studies on patients from across of the world might be required to validate our findings.

  8. Projectile Base Flow Analysis

    DTIC Science & Technology

    2007-11-02

    S) AND ADDRESS(ES) DCW Industries, Inc. 5354 Palm Drive La Canada, CA 91011 8. PERFORMING ORGANIZATION...REPORT NUMBER DCW -38-R-05 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U. S. Army Research Office...Turbulence Modeling for CFD, Second Edition, DCW Industries, Inc., La Cañada, CA. Wilcox, D. C. (2001), “Projectile Base Flow Analysis,” DCW

  9. Embedded Controller based Image Stabilizer

    NASA Astrophysics Data System (ADS)

    Teare, S. W.; Lamppa, D.; Sugimoto, K.; Yates, J.; Xiao, H.; Thompson, L. A.

    2004-05-01

    An image stabilization system is commonly used on astronomical telescopes to compensate for poor mount performance, low-order effects from atmospheric seeing and local index of refraction instabilities near the telescope. An image stabilizer is comprised of an electro-optical component and a sensor that are used in concert to lock the position of a wavefront or image centroid onto a camera. There are several commercial tip-tilt and sensing systems and components that can be used for image stabilization depending on the user's performance and cost requirements. We report on an inexpensive image stabilizer for use on astronomical telescopes developed as part of the NSF funded (AST-00-96741) UnISIS laser guide-star project at the Mount Wilson Observatory. The instrument uses inexpensive, commercial-off-the-shelf (COTS) components for beam steering, position sensing and the processor/control system. The limiting magnitude of the system depends on the properties of the light sensor used. The image stabilizer operates as a turnkey system with 2 main control modes to provide different performance capabilities for different operating conditions. The normal mode uses a proportional, integrating, differentiating (PID) controller and the second mode uses a more complex fuzzy logic based control scheme. We have examined other control methods and continue to experiment with different schemes. The simplicity of the system allows for many different control models to be implemented and evaluated in the laboratory and on the telescope. This flexibility and low cost provides an inexpensive system that can be used for both image stabilization and monitoring of the astronomical seeing at an observing site. Such systems are also invaluable for introducing astronomy students to instrumentation and engineering students to the innovative control aspects of telescope systems.

  10. Trajectories of Suicidal Ideation in People Seeking Web-Based Help for Suicidality: Secondary Analysis of a Dutch Randomized Controlled Trial

    PubMed Central

    van Spijker, Bregje; Karstoft, Karen-Inge; Nordentoft, Merete; Kerkhof, Ad JFM

    2016-01-01

    Background Suicidal ideation (SI) is a common mental health problem. Variability in intensity of SI over time has been linked to suicidal behavior, yet little is known about the temporal course of SI. Objective The primary aim was to identify prototypical trajectories of SI in the general population and, secondarily, to examine whether receiving Web-based self-help for SI, psychiatric symptoms, or sociodemographics predicted membership in the identified SI trajectories. Methods We enrolled 236 people, from the general Dutch population seeking Web-based help for SI, in a randomized controlled trial comparing a Web-based self-help for SI group with a control group. We assessed participants at inclusion and at 2, 4, and 6 weeks. The Beck Scale for Suicide Ideation was applied at all assessments and was included in latent growth mixture modeling analysis to empirically identify trajectories. Results We identified 4 SI trajectories. The high stable trajectory represented 51.7% (122/236) of participants and was characterized by constant high level of SI. The high decreasing trajectory (50/236, 21.2%) consisted of people with a high baseline SI score followed by a gradual decrease to a very low score. The third trajectory, high increasing (12/236, 5.1%), also had high initial SI score, followed by an increase to the highest level of SI at 6 weeks. The fourth trajectory, low stable (52/236, 22.0%) had a constant low level of SI. Previous attempted suicide and having received Web-based self-help for SI predicted membership in the high decreasing trajectory. Conclusions Many adults experience high persisting levels of SI, though results encouragingly indicate that receiving Web-based self-help for SI increased membership in a decreasing trajectory of SI. PMID:27363482

  11. Theory-based self-management educational interventions on patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Zhao, Fang-Fang; Suhonen, Riitta; Koskinen, Sanna; Leino-Kilpi, Helena

    2017-04-01

    To synthesize the effects of theory-based self-management educational interventions on patients with type 2 diabetes (T2DM) in randomized controlled trials. Type 2 diabetes is a common chronic disease causing complications that put a heavy burden on society and reduce the quality of life of patients. Good self-management of diabetes can prevent complications and improve the quality of life of T2DM patients. Systematic review with meta-analysis of randomized controlled trials following Cochrane methods. A literature search was carried out in the MEDLINE, EMBASE, CINAHL, PSYCINFO, and Web of Science databases (1980-April 2015). The risk of bias of these eligible studies was assessed independently by two authors using the Cochrane Collaboration's tool. The Publication bias of the main outcomes was examined. Statistical heterogeneity and random-effects model were used for meta-analysis. Twenty studies with 5802 participants met the inclusion criteria. The interventions in the studies were based on one or more theories which mostly belong to mid-range theories. The pooled main outcomes by random-effects model showed significant improvements in HbA1c, self-efficacy, and diabetes knowledge, but not in BMI. As for quality of life, no conclusions can be drawn as the pooled outcome became the opposite with reduced heterogeneity after one study was excluded. No significant publication bias was found in the main outcomes. To get theory-based interventions to produce more effects, the role of patients should be more involved and stronger and the education team should be trained beyond the primary preparation for the self-management education program. © 2016 John Wiley & Sons Ltd.

  12. Genetic identification of istiophorid larvae from the Gulf of Mexico based on the analysis of mitochondrial DNA control region sequences.

    PubMed

    McKenzie, J L; Alvarado Bremer, J R

    2017-03-01

    Assigning relative importance of spawning and nursery habitats for threatened and endangered teleosts, such as those seen in the Gulf of Mexico (GoM), relies on the proper identification of the early life-history stages of the species of concern. Here, sequencing a portion of the mitochondrial DNA (mtDNA) control region (CR) I as barcodes is recommended to identify istiophorid (billfish) larvae in the Atlantic Ocean because of its high resolution and the intrinsic value of the levels of genetic variation that can be extracted from these data. The universality of the primers employed here demonstrates their utility for not only the positive identification of istiophorids in the GoM, but for any larval teleost occurring in areas recognized as larval hotspots worldwide. © 2016 The Fisheries Society of the British Isles.

  13. Critical Analysis of Dry Storage Temperature Limits for Zircaloy-Clad Spent Nuclear Fuel Based on Diffusion Controlled Cavity Growth

    SciTech Connect

    Hayes, T.A.; Rosen, R.S.; Kassner, M.E.

    1999-12-01

    Interim dry storage of spent nuclear fuel (SNF) rods is of critical concern because a shortage of existing SNF wet storage capacity combined with delays in the availability of a permanent disposal repository has led to an increasing number of SNF rods being placed into interim dry storage. Safe interim dry storage must be maintained for a minimum of twenty years according to the Standard Review Plan for Dry Cask Storage Systems [1] and the Code of Federal Regulations, 10 CFR Part 72 [2]. Interim dry storage licensees must meet certain safety conditions when storing SNF rods to ensure that there is a ''very low probability (e.g. 0.5%) of cladding breach during long-term storage'' [1]. Commercial SNF typically consists of uranium oxide pellets surrounded by a thin cladding. The cladding is usually an {alpha}-zirconium based alloy know as ''Zircaloy''. In dry storage, the SNF rods are confined in one of several types of cask systems approved by the Nuclear Regulatory Commission (NRC). ''The cask system must be designed to prevent degradation of fuel cladding that results in a type of cladding breach, such as axial-splits or ductile fracture, where irradiated UO{sub 2} particles may be released. In addition, the fuel cladding should not degrade to the point where more than one percent of the fuel rods suffer pinhole or hairline crack type failure under normal storage conditions [1].'' The NRC has approved two models [3,4] for use by proposed dry storage licensees to determine the maximum initial temperature limit for nuclear fuel rods in dry storage that supposedly meet the above criteria and yield consistent temperature limits. Though these two models are based on the same fundamental failure theory, different assumptions have been made including the choice of values for material constants in the failure equation. This report will examine and compare the similarities and inconsistencies of these two models. It will illustrate some of the shortcomings of the current

  14. Karyopherin-Centric Control of Nuclear Pores Based on Molecular Occupancy and Kinetic Analysis of Multivalent Binding with FG Nucleoporins

    PubMed Central

    Kapinos, Larisa E.; Schoch, Rafael L.; Wagner, Raphael S.; Schleicher, Kai D.; Lim, Roderick Y.H.

    2014-01-01

    Intrinsically disordered Phe-Gly nucleoporins (FG Nups) within nuclear pore complexes exert multivalent interactions with transport receptors (Karyopherins (Kaps)) that orchestrate nucleocytoplasmic transport. Current FG-centric views reason that selective Kap translocation is promoted by alterations in the barrier-like FG Nup conformations. However, the strong binding of Kaps with the FG Nups due to avidity contradicts rapid Kap translocation in vivo. Here, using surface plasmon resonance, we innovate a means to correlate in situ mechanistic (molecular occupancy and conformational changes) with equilibrium (binding affinity) and kinetic (multivalent binding kinetics) aspects of Karyopherinβ1 (Kapβ1) binding to four different FG Nups. A general feature of the FxFG domains of Nup214, Nup62, and Nup153 is their capacity to extend and accommodate large numbers of Kapβ1 molecules at physiological Kapβ1 concentrations. A notable exception is the GLFG domain of Nup98, which forms a partially penetrable cohesive layer. Interestingly, we find that a slowly exchanging Kapβ1 phase forms an integral constituent within the FG Nups that coexists with a fast phase, which dominates transport kinetics due to limited binding with the pre-occupied FG Nups at physiological Kapβ1 concentrations. Altogether, our data reveal an emergent Kap-centric barrier mechanism that may underlie mechanistic and kinetic control in the nuclear pore complex. PMID:24739174

  15. Karyopherin-centric control of nuclear pores based on molecular occupancy and kinetic analysis of multivalent binding with FG nucleoporins.

    PubMed

    Kapinos, Larisa E; Schoch, Rafael L; Wagner, Raphael S; Schleicher, Kai D; Lim, Roderick Y H

    2014-04-15

    Intrinsically disordered Phe-Gly nucleoporins (FG Nups) within nuclear pore complexes exert multivalent interactions with transport receptors (Karyopherins (Kaps)) that orchestrate nucleocytoplasmic transport. Current FG-centric views reason that selective Kap translocation is promoted by alterations in the barrier-like FG Nup conformations. However, the strong binding of Kaps with the FG Nups due to avidity contradicts rapid Kap translocation in vivo. Here, using surface plasmon resonance, we innovate a means to correlate in situ mechanistic (molecular occupancy and conformational changes) with equilibrium (binding affinity) and kinetic (multivalent binding kinetics) aspects of Karyopherinβ1 (Kapβ1) binding to four different FG Nups. A general feature of the FxFG domains of Nup214, Nup62, and Nup153 is their capacity to extend and accommodate large numbers of Kapβ1 molecules at physiological Kapβ1 concentrations. A notable exception is the GLFG domain of Nup98, which forms a partially penetrable cohesive layer. Interestingly, we find that a slowly exchanging Kapβ1 phase forms an integral constituent within the FG Nups that coexists with a fast phase, which dominates transport kinetics due to limited binding with the pre-occupied FG Nups at physiological Kapβ1 concentrations. Altogether, our data reveal an emergent Kap-centric barrier mechanism that may underlie mechanistic and kinetic control in the nuclear pore complex. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. Takagi-Sugeno model based analysis of EWMA RtR control of batch processes with stochastic metrology delay and mixed products.

    PubMed

    Zheng, Ying; Wong, David Shan-Hill; Wang, Yan-Wei; Fang, Huajing

    2014-07-01

    In many batch-based industrial manufacturing processes, feedback run-to-run control is used to improve production quality. However, measurements may be expensive and cannot always be performed online. Thus, the measurement delay always exists. The metrology delay will affect the stability and performance of the process. Moreover, since quality measurements are performed offline, delay is not fixed but is stochastic in nature. In this paper, a modeling approach Takagi-Sugeno (T-S) model is presented to handle stochastic metrology delay in both single-product and mixed-product processes. Based on the Markov characteristics of the delay, the membership of the T-S model is derived. Performance indices such as the mean and the variance of the closed-loop output of the exponentially weighted moving average (EWMA) control algorithm can be derived. A steady-state error of the process output always exists, which leads the output deviating from the target. To remove the steady-state error, an algorithm called compensatory EWMA run-to-run (COM-EWMA-RtR) algorithm is proposed. The validity of the T-S model analysis and the efficiency of the proposed COM-EWMA-RtR algorithm are confirmed by simulation.

  17. Application of Risk Analysis Based On Remote Sensing and Geographic Information System Technologies To Control of Malaria In Nigeria

    NASA Astrophysics Data System (ADS)

    Njemanze, Philip; Njemanze, Philip; Peters, Constance; Uwaeziozi, Amarachukwu

    More than 1 million Africans die from malaria each year. Remote sensing (RS) and geographic information system (GIS) technologies could be applied to study the risk of malaria epidemic. The patient population included 45,140 of persons aged 0-85 years seen at primary health centers in 18 different local government areas (LGAs) of Imo State. Maps of old Imo State were converted to digital form using ARC/INFO GIS software, and the resulting coverages included hydrology, towns, and villages. Remote sensing images from Advanced Very High Resolution Radiometer (AVHRR) data set were used to obtain color-coded monthly normalized-difference vegetation index or NDVI. Three groups were distinguished as: group A LGAs using water from natural hydrology and bore-holes, group B - using rain water harvesting from roof tops into surface water reservoirs, and group C - using ground surface catchment of rain water with ground ponds. These stagnant ponds were Anopheles mosquito breeding sites. The NDVI values were used to determine water availability, and were least in January/February each year, and highest in April/May. Probabilistic layer analysis (PLA) was used to determine the Odds Ratio (OR), Relative Risk (RR) and Attributable Risk (AR) for malaria in groups A, B, C. Significant risk for malaria was associated with local water conservation methods in group C, compared to A, (OR = 4.55; RR = 4.46, AR = 77.6

  18. Influence of long-term wearing of unstable shoes on compensatory control of posture: an electromyography-based analysis.

    PubMed

    Sousa, Andreia S P; Silva, Andreia; Macedo, Rui; Santos, Rubim; Tavares, João Manuel R S

    2014-01-01

    This study investigated the influence of long-term wearing of unstable shoes (WUS) on compensatory postural adjustments (CPA) to an external perturbation. Participants were divided into two groups: one wore unstable shoes while the other wore conventional shoes for 8 weeks. The ground reaction force signal was used to calculate the anterior-posterior (AP) displacement of the centre of pressure (CoP) and the electromyographic signal of gastrocnemius medialis (GM), tibialis anterior (TA), rectus femoris (RF) and biceps femoris (BF) muscles was used to assess individual muscle activity, antagonist co-activation and reciprocal activation at the joint (TA/GM and RF/(BF+GM) pairs) and muscle group levels (ventral (TA+RF)/dorsal (GM+BF) pair) within time intervals typical for CPA. The electromyographic signal was also used to assess muscle latency. The variables described were evaluated before and after the 8-week period while wearing the unstable shoes and barefoot. Long-term WUS led to: an increase of BF activity in both conditions (barefoot and wearing the unstable shoes); a decrease of GM activity; an increase of antagonist co-activation and a decrease of reciprocal activation level at the TA/GM and ventral/dorsal pairs in the unstable shoe condition. Additionally, WUS led to a decrease in CoP displacement. However, no differences were observed in muscle onset and offset. Results suggest that the prolonged use of unstable shoes leads to increased ankle and muscle groups' antagonist co-activation levels and higher performance by the postural control system. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Polyphenol-based nutraceuticals for the control of angiogenesis: Analysis of the critical issues for human use.

    PubMed

    Morbidelli, Lucia

    2016-09-01

    Angiogenesis, the formation of new blood-vessel, is crucial in the pathogenesis of several diseases, and thus represents a druggable target for the prevention and treatment of different disorders. It is nowadays well kwon how diet can control cancer development and progression, and how the use of certain diet components can prevent cancer development. Several studies, also from our lab, now indicate that natural plant products including nutraceuticals modulate tumor angiogenesis. In this review, it is reported how phytochemicals, comprising hydroxytyrosol, resveratrol, genistein, curcumin, and the green tea component epigallocatechin-3-gallate among the others, negatively regulate angiogenesis. A single plant-derived compound may affect both endothelial and tumor cells, with the common denominator of anti-inflammatory and radical scavenger activities. Beside these positive features, documented in cellular and animal models, a series of critical issues should be considered from a pharmacological point of view as: what is the best source of bioactive compounds: food and beverages, extracted phytocomplexes, isolated nutraceuticals or synthetic analogues? How is the bioavailability of the compounds of interest in relation to the above source? Is there any biological activity by circulating metabolic derivatives? What is the best formulation, administration route and posology? How safe are in humans? How strong and reliable are the clinical trials designed for their use alone or in combination with conventional chemotherapy? After a dissertation of these critical points, the conclusion can be drawn that novel and effective strategies should be optimized to improve their bioavailability and efficacy, considering their exploitation as chemopreventive and/or curative approaches.

  20. Characterization of Physical Controls on Stream Base-flow and the Flux of Surface Water and Groundwater Using Multivariate Analysis in the Northern Great Plains

    NASA Astrophysics Data System (ADS)

    Bednar, J. M.; Long, A. J.

    2015-12-01

    Stream base-flow estimation is commonly performed by using graphical or chemical hydrograph separation methods that have limitations due to the spatial and temporal availability of data. Current graphical separation methods are limited in that they rely solely on streamflow records, whereas chemical methods are expensive and involve intense data collection. Graphical hydrograph separation methods are applicable to perennial and gaining streams but result in large uncertainty when applied to ephemeral or losing streams that are typical of dry climates. A new method planned for development will consist of multivariate analysis to determine which spatial and temporal variables are the controlling factors for base flow. Data used in the development of this methodology will include geologic, hydrologic, climatic, land surface, and remotely sensed data that are widely available to the public. Factors considered will include geologic media, flow-duration curves, temporal variability of streamflow, stream type, precipitation, drought-severity index, land-surface slope, and vegetation. This research will examine differences in variables controlling base flow between dry and humid climates, perennial and ephemeral streams, and gaining and losing stream reaches. Although the accuracy of each variable will vary, the use of multivariate analyses will help compensate for those variables with low accuracy. Base-flow estimates were previously calculated for all streams with streamflow data located in the Williston and Powder River structural basins using the U.S. Geological Survey hydrograph separation software, PART; these streams, in addition to streams not previously analyzed, will be evaluated by using the method that is being developed. The study area for this research will include the Heart River basin in southwestern North Dakota, the White River basin in southwestern South Dakota, and the Niobrara River basin in northern Nebraska.

  1. A Bayesian cost-effectiveness analysis of a telemedicine-based strategy for the management of sleep apnoea: a multicentre randomised controlled trial.

    PubMed

    Isetta, Valentina; Negrín, Miguel A; Monasterio, Carmen; Masa, Juan F; Feu, Nuria; Álvarez, Ainhoa; Campos-Rodriguez, Francisco; Ruiz, Concepción; Abad, Jorge; Vázquez-Polo, Francisco J; Farré, Ramon; Galdeano, Marina; Lloberes, Patricia; Embid, Cristina; de la Peña, Mónica; Puertas, Javier; Dalmases, Mireia; Salord, Neus; Corral, Jaime; Jurado, Bernabé; León, Carmen; Egea, Carlos; Muñoz, Aida; Parra, Olga; Cambrodi, Roser; Martel-Escobar, María; Arqué, Meritxell; Montserrat, Josep M

    2015-11-01

    Compliance with continuous positive airway pressure (CPAP) therapy is essential in patients with obstructive sleep apnoea (OSA), but adequate control is not always possible. This is clinically important because CPAP can reverse the morbidity and mortality associated with OSA. Telemedicine, with support provided via a web platform and video conferences, could represent a cost-effective alternative to standard care management. To assess the telemedicine impact on treatment compliance, cost-effectiveness and improvement in quality of life (QoL) when compared with traditional face-to-face follow-up. A randomised controlled trial was performed to compare a telemedicine-based CPAP follow-up strategy with standard face-to-face management. Consecutive OSA patients requiring CPAP treatment, with sufficient internet skills and who agreed to participate, were enrolled. They were followed-up at 1, 3 and 6 months and answered surveys about sleep, CPAP side effects and lifestyle. We compared CPAP compliance, cost-effectiveness and QoL between the beginning and the end of the study. A Bayesian cost-effectiveness analysis with non-informative priors was performed. We randomised 139 patients. At 6 months, we found similar levels of CPAP compliance, and improved daytime sleepiness, QoL, side effects and degree of satisfaction in both groups. Despite requiring more visits, the telemedicine group was more cost-effective: costs were lower and differences in effectiveness were not relevant. A telemedicine-based strategy for the follow-up of CPAP treatment in patients with OSA was as effective as standard hospital-based care in terms of CPAP compliance and symptom improvement, with comparable side effects and satisfaction rates. The telemedicine-based strategy had lower total costs due to savings on transport and less lost productivity (indirect costs). NCT01716676. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go

  2. Software based controls module development

    SciTech Connect

    Graves, v.b.; kelley, g; welch, j.c.

    1999-12-10

    A project was initiated at the Oak Ridge Y-12 Plant to implement software geometric error compensation within a PC-based machine tool controller from Manufacturing Data Systems, Inc. This project may be the first in which this type of compensation system was implemented in a commercially available machine tool controller totally in software. Previous implementations typically required using an external computer and hardware to interface through the position feedback loop of the controller because direct access to the controller software was not available. The test-bed machine for this project was a 2-axis Excello 921 T-base lathe. A mathematical error model of the lathe was created using homogeneous transformation matrices to relate the positions of the machine's slides to each other and to a world reference system. Equations describing the effects of the geometric errors were derived from the model. A software architecture was developed to support geometric error compensation for machine tools with up to 3 linear axes. Rotary axes were not supported in this implementation, but the developed architecture would not preclude their support in the future. Specific implementations will be dependent upon the configuration of the machine tool. A laser measuring system from Automated Precision, Inc. was used to characterize the lathe's geometric errors as functions of axis position and direction of motion. Multiple data files generated by the laser system were combined into a single Error File that was read at system startup and used by the compensation system to provide real-time position adjustments to the axis servos. A Renishaw Ballbar was used to evaluate the compensation system. Static positioning tests were conducted in an attempt to observe improved positioning accuracy with the compensation system enabled. These tests gave inconsistent results due to the lathe's inability to position the tool repeatably. The development of the architecture and compensation

  3. Control volume based hydrocephalus research

    NASA Astrophysics Data System (ADS)

    Cohen, Benjamin; Voorhees, Abram; Wei, Timothy

    2008-11-01

    Hydrocephalus is a disease involving excess amounts of cerebral spinal fluid (CSF) in the brain. Recent research has shown correlations to pulsatility of blood flow through the brain. However, the problem to date has presented as too complex for much more than statistical analysis and understanding. This talk will highlight progress on developing a fundamental control volume approach to studying hydrocephalus. The specific goals are to select physiologically control volume(s), develop conservation equations along with the experimental capabilities to accurately quantify terms in those equations. To this end, an in vitro phantom is used as a simplified model of the human brain. The phantom's design consists of a rigid container filled with a compressible gel. The gel has a hollow spherical cavity representing a ventricle and a cylindrical passage representing the aquaducts. A computer controlled piston pump supplies pulsatile volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity, and volume change as functions of time. Independent pressure measurements and flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients.

  4. Social network analysis of Equidae movements and its application to risk-based surveillance and to control of spread of potential Equidae diseases.

    PubMed

    Sánchez-Matamoros, A; Martínez-López, B; Sánchez-Vizcaíno, F; Sánchez-Vizcaíno, J M

    2013-10-01

    Movements of animals and animal products are one of the most important ways of disease introduction and spread between regions and countries. Maybe one of the most complex animal species in terms of diversity of uses, nature and extent of movements are equidae, for which animal movement records are usually not available. The study presented here is the first characterization of a complete and reliable network of equidae movements in Castile and Leon, which is one of the most important equidae production regions of Spain. Social network analysis and space-time cluster analysis were used to describe the contact patterns of the equidae network and to identify the most important premises, areas and time periods for potential disease introduction or spread into the region. The studied network was complex, with very heterogeneous types of premises and diverse nature and extent of the movements compared with other livestock species, which have important implications for prevention and control of equidae diseases. Centrality measures revealed that production and reproduction farms and centres of livestock competition were the most important type of premises in the studied network. Cluster analyses allowed to identify seventeen significant spatio-temporal clusters of premises at high risk of dispatching or receiving equidae, which formed four interconnected compartments. These clusters were mainly located in the north-west region and in the second part of the year. The results of this study may be useful to design risk-based surveillance and control programmes of equidae diseases and increase the speed of detection and control of potential secondary outbreaks in future epidemics. Consequently, these results will help to minimize the great economic and sanitary impact of equidae diseases. The analytical approach used here may be easily extended to characterize the equidae movement patterns in other countries and regions of the world. © 2012 Blackwell Verlag GmbH.

  5. Convenient and Efficient Method for Quality Control Analysis of 18F-Fluorocholine: For a Small Scale GMP-based Radiopharmaceuticals Laboratory Set-up.

    PubMed

    Hassan, Hishar; Abu Bakar, Suharzelim; Halim, Khairul Najah Che A; Idris, Jaleezah; Nordin, Abdul Jalil

    2016-01-01

    Prostate cancer continues to be the most prevalent cancer in men in Malaysia. As time progresses, the prospect of PET imaging modality in diagnosis of prostate cancer is promising, with on-going improvement on novel tracers. Among all tracers, 18F-Fluorocholine is reported to be a reputable tracer and reliable diagnostic technique for prostate imaging. Nonetheless, only 18F-Fluorodeoxyglucose (18F-FDG) is available and used in most oncology cases in Malaysia. With a small scale GMP-based radiopharmaceuticals laboratory set-up, initial efforts have been taken to put Malaysia on 18F-Fluorocholine map. This article presents a convenient, efficient and reliable method for quality control analysis of 18F-Fluorocholine. Besides, the aim of this research work is to assist local GMP radiopharmaceuticals laboratories and local authority in Malaysia for quality control analysis of 18F-Fluorocholine guideline. In this study, prior to synthesis, quality control analysis method for 18F-Fluorocholine was developed and validated, by adapting the equipment set-up used in 18F-Fluorodeoxyglucose (18FFDG) routine production. Quality control on the 18F-Fluorocholine was performed by means of pH, radionuclidic identity, radio-high performance liquid chromatography equipped with ultraviolet, radio- thin layer chromatography, gas chromatography and filter integrity test. Post-synthesis; the pH of 18F-Fluorocholine was 6.42 ± 0.04, with half-life of 109.5 minutes (n = 12). The radiochemical purity was consistently higher than 99%, both in radio-high performance liquid chromatography equipped with ultraviolet (r-HPLC; SCX column, 0.25 M NaH2PO4: acetonitrile) and radio-thin layer chromatography method (r-TLC). The calculated relative retention time (RRT) in r-HPLC was 1.02, whereas the retention factor (Rf) in r-TLC was 0.64. Potential impurities from 18F-Fluorocholine synthesis such as ethanol, acetonitrile, dimethylethanolamine and dibromomethane were determined in gas chromatography

  6. Web-based physical activity interventions: a systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Jahangiry, Leila; Farhangi, Mahdieh Abbasalizad; Shab-Bidar, Sakineh; Rezaei, Fatemeh; Pashaei, T

    2017-07-20

    It was estimated that approximately 60% of the world's population is classified as inactive or insufficiently active. This meta-analysis investigated the effect of web-based interventions on different types of physical activity (PA) measurements in general population and potential moderating variables. PubMed, CINAHL, EBSCOhost, PsycINFO, Scopus, Ovid, and ScienceDirect literature searches were conducted to identify studies investigating the effect of web-based interventions on PA. Randomized controlled trials on PA changes reported in moderate to vigorous intensity, walking, and step count in the intervention group in comparison with the control group were pooled with a fixed-effects model separately. A total of 22 studies comprising 16,476 and 14,475 subjects in intervention and control groups respectively were included. Web-based interventions had positive and significant effect on increasing PA. Of 14 trials reporting moderate to vigorous physical activity (MVPA), five showed a significant increase in the MVPA level after the intervention. There was significant heterogeneity between studies (P < 0.001 and I(2) = 67.8%). Of six trials that reported the number of steps by using the pedometer, three showed a significant increase for the step counts in intervention groups (P < 0.001 and I(2) = 93.3%), of 14 trials assessed PA level by reporting walking minutes per week, four studies showed a significant increase in walking minutes. There was significant heterogeneity between studies (P < 0.001, I(2) = 68.1%). Overall, the effect of web-based interventions seemed to be influenced by the characteristics of mean age of participants, trial duration, and study quality (P < 0.05). The web-based PA interventions had a positive significant effect on increasing all the three types of PA among the general population. However, the effects appear to depend on the design of the study, age, and duration of studies. Copyright © 2017 The Royal Society for Public

  7. Mindfulness-Based Interventions for People Diagnosed with a Current Episode of an Anxiety or Depressive Disorder: A Meta-Analysis of Randomised Controlled Trials

    PubMed Central

    Strauss, Clara; Cavanagh, Kate; Oliver, Annie; Pettman, Danelle

    2014-01-01

    Objective Mindfulness-based interventions (MBIs) can reduce risk of depressive relapse for people with a history of recurrent depression who are currently well. However, the cognitive, affective and motivational features of depression and anxiety might render MBIs ineffective for people experiencing current symptoms. This paper presents a meta-analysis of randomised controlled trials (RCTs) of MBIs where participants met diagnostic criteria for a current episode of an anxiety or depressive disorder. Method Post-intervention between-group Hedges g effect sizes were calculated using a random effects model. Moderator analyses of primary diagnosis, intervention type and control condition were conducted and publication bias was assessed. Results Twelve studies met inclusion criteria (n = 578). There were significant post-intervention between-group benefits of MBIs relative to control conditions on primary symptom severity (Hedges g = −0.59, 95% CI = −0.12 to −1.06). Effects were demonstrated for depressive symptom severity (Hedges g = −0.73, 95% CI = −0.09 to −1.36), but not for anxiety symptom severity (Hedges g = −0.55, 95% CI = 0.09 to −1.18), for RCTs with an inactive control (Hedges g = −1.03, 95% CI = −0.40 to −1.66), but not where there was an active control (Hedges g = 0.03, 95% CI = 0.54 to −0.48) and effects were found for MBCT (Hedges g = −0.39, 95% CI = −0.15 to −0.63) but not for MBSR (Hedges g = −0.75, 95% CI = 0.31 to −1.81). Conclusions This is the first meta-analysis of RCTs of MBIs where all studies included only participants who were diagnosed with a current episode of a depressive or anxiety disorder. Effects of MBIs on primary symptom severity were found for people with a current depressive disorder and it is recommended that MBIs might be considered as an intervention for this population. PMID:24763812

  8. Mindfulness-based interventions for people diagnosed with a current episode of an anxiety or depressive disorder: a meta-analysis of randomised controlled trials.

    PubMed

    Strauss, Clara; Cavanagh, Kate; Oliver, Annie; Pettman, Danelle

    2014-01-01

    Mindfulness-based interventions (MBIs) can reduce risk of depressive relapse for people with a history of recurrent depression who are currently well. However, the cognitive, affective and motivational features of depression and anxiety might render MBIs ineffective for people experiencing current symptoms. This paper presents a meta-analysis of randomised controlled trials (RCTs) of MBIs where participants met diagnostic criteria for a current episode of an anxiety or depressive disorder. Post-intervention between-group Hedges g effect sizes were calculated using a random effects model. Moderator analyses of primary diagnosis, intervention type and control condition were conducted and publication bias was assessed. Twelve studies met inclusion criteria (n = 578). There were significant post-intervention between-group benefits of MBIs relative to control conditions on primary symptom severity (Hedges g = -0.59, 95% CI = -0.12 to -1.06). Effects were demonstrated for depressive symptom severity (Hedges g = -0.73, 95% CI = -0.09 to -1.36), but not for anxiety symptom severity (Hedges g = -0.55, 95% CI = 0.09 to -1.18), for RCTs with an inactive control (Hedges g = -1.03, 95% CI = -0.40 to -1.66), but not where there was an active control (Hedges g = 0.03, 95% CI = 0.54 to -0.48) and effects were found for MBCT (Hedges g = -0.39, 95% CI = -0.15 to -0.63) but not for MBSR (Hedges g = -0.75, 95% CI = 0.31 to -1.81). This is the first meta-analysis of RCTs of MBIs where all studies included only participants who were diagnosed with a current episode of a depressive or anxiety disorder. Effects of MBIs on primary symptom severity were found for people with a current depressive disorder and it is recommended that MBIs might be considered as an intervention for this population.

  9. Salt-Rich Selenium for Prevention and Control Children with Kashin-Beck Disease: a Meta-analysis of Community-Based Trial.

    PubMed

    Yu, Fang-fang; Han, Jing; Wang, Xi; Fang, Hua; Liu, Huan; Guo, Xiong

    2016-03-01

    Kashin-Beck disease (KBD) in western China is not well controlled. The objective of this study is to evaluate prevention and control children with KBD through a meta-analysis of a community-based trial. Web of knowledge, PubMed, Elsevier, the Chinese National Knowledge Infrastructure (CNKI), VIP and Wanfang data had been electronically searched up to February 2015. Search terms included the trial terms "Salt rich selenium" and "Kashin-Beck disease." Eligible studies were prospective trials of salt-rich selenium in endemic villages. Data extraction was performed by two authors using predefined data fields that also included quality evaluation. Of 292 potentially relevant articles initially screened, reporting 11 community-based trials with a total enrollment of 2652 participants were included, from five provinces in China. The pooled odds ratios (OR) and 95 % confidence intervals (CI) of primary prevention in healthy children were 0.16 and 0.08∼0.33, respectively. The OR and 95 % CI of clinical improvement in KBD children were 6.57 and 3.33∼12.93, respectively. The OR of repairing rate of metaphysis lesions was 5.53 (95 % CI 2.92∼10.47) based on X-ray film, which was statistically significantly different in favor of salt-rich selenium. The combined standard mean difference (SMD) of selenium content in hair was 2.54 (95 % CI 1.21∼3.87) which was significantly higher in selenium group. Current evidence showed that supplement salt-rich selenium was effective in reducing new incidence in healthy children and clinical improvement including repairing metaphysis lesions instead of repairing distal end of phalanx lesions in KBD children.

  10. Haplotype-Based Regression Analysis and Inference of Case–Control Studies with Unphased Genotypes and Measurement Errors in Environmental Exposures

    PubMed Central

    Lobach, Iryna; Carroll, Raymond J.; Spinka, Christine; Gail, Mitchell H.; Chatterjee, Nilanjan

    2009-01-01

    Summary. It is widely believed that risks of many complex diseases are determined by genetic susceptibilities, environmental exposures, and their interaction. Chatterjee and Carroll (2005, Biometrika 92, 399–418) developed an efficient retrospective maximum-likelihood method for analysis of case–control studies that exploits an assumption of gene–environment independence and leaves the distribution of the environmental covariates to be completely nonparametric. Spinka, Carroll, and Chatterjee (2005, Genetic Epidemiology 29, 108–127) extended this approach to studies where certain types of genetic information, such as haplotype phases, may be missing on some subjects. We further extend this approach to situations when some of the environmental exposures are measured with error. Using a polychotomous logistic regression model, we allow disease status to have K + 1 levels. We propose use of a pseudolikelihood and a related EM algorithm for parameter estimation. We prove consistency and derive the resulting asymptotic covariance matrix of parameter estimates when the variance of the measurement error is known and when it is estimated using replications. Inferences with measurement error corrections are complicated by the fact that the Wald test often behaves poorly in the presence of large amounts of measurement error. The likelihood-ratio (LR) techniques are known to be a good alternative. However, the LR tests are not technically correct in this setting because the likelihood function is based on an incorrect model, i.e., a prospective model in a retrospective sampling scheme. We corrected standard asymptotic results to account for the fact that the LR test is based on a likelihood-type function. The performance of the proposed method is illustrated using simulation studies emphasizing the case when genetic information is in the form of haplotypes and missing data arises from haplotype-phase ambiguity. An application of our method is illustrated using a

  11. Pharmacogenetics-based warfarin dosing algorithm decreases time to stable anticoagulation and the risk of major hemorrhage: an updated meta-analysis of randomized controlled trials.

    PubMed

    Wang, Zhi-Quan; Zhang, Rui; Zhang, Peng-Pai; Liu, Xiao-Hong; Sun, Jian; Wang, Jun; Feng, Xiang-Fei; Lu, Qiu-Fen; Li, Yi-Gang

    2015-04-01

    Warfarin is yet the most widely used oral anticoagulant for thromboembolic diseases, despite the recently emerged novel anticoagulants. However, difficulty in maintaining stable dose within the therapeutic range and subsequent serious adverse effects markedly limited its use in clinical practice. Pharmacogenetics-based warfarin dosing algorithm is a recently emerged strategy to predict the initial and maintaining dose of warfarin. However, whether this algorithm is superior over conventional clinically guided dosing algorithm remains controversial. We made a comparison of pharmacogenetics-based versus clinically guided dosing algorithm by an updated meta-analysis. We searched OVID MEDLINE, EMBASE, and the Cochrane Library for relevant citations. The primary outcome was the percentage of time in therapeutic range. The secondary outcomes were time to stable therapeutic dose and the risks of adverse events including all-cause mortality, thromboembolic events, total bleedings, and major bleedings. Eleven randomized controlled trials with 2639 participants were included. Our pooled estimates indicated that pharmacogenetics-based dosing algorithm did not improve percentage of time in therapeutic range [weighted mean difference, 4.26; 95% confidence interval (CI), -0.50 to 9.01; P = 0.08], but it significantly shortened the time to stable therapeutic dose (weighted mean difference, -8.67; 95% CI, -11.86 to -5.49; P < 0.00001). Additionally, pharmacogenetics-based algorithm significantly reduced the risk of major bleedings (odds ratio, 0.48; 95% CI, 0.23 to 0.98; P = 0.04), but it did not reduce the risks of all-cause mortality, total bleedings, or thromboembolic events. Our results suggest that pharmacogenetics-based warfarin dosing algorithm significantly improves the efficiency of International Normalized Ratio correction and reduces the risk of major hemorrhage.

  12. Experiment-Based Teaching in Advanced Control Engineering

    ERIC Educational Resources Information Center

    Precup, R.-E.; Preitl, S.; Radac, M.-B.; Petriu, E. M.; Dragos, C.-A.; Tar, J. K.

    2011-01-01

    This paper discusses an experiment-based approach to teaching an advanced control engineering syllabus involving controlled plant analysis and modeling, control structures and algorithms, real-time laboratory experiments, and their assessment. These experiments are structured around the representative case of the longitudinal slip control of an…

  13. Experiment-Based Teaching in Advanced Control Engineering

    ERIC Educational Resources Information Center

    Precup, R.-E.; Preitl, S.; Radac, M.-B.; Petriu, E. M.; Dragos, C.-A.; Tar, J. K.

    2011-01-01

    This paper discusses an experiment-based approach to teaching an advanced control engineering syllabus involving controlled plant analysis and modeling, control structures and algorithms, real-time laboratory experiments, and their assessment. These experiments are structured around the representative case of the longitudinal slip control of an…

  14. Effects of the feeling of invulnerability and the feeling of control on motivation to participate in experience-based analysis, by type of risk.

    PubMed

    Mbaye, Safiétou; Kouabenan, Dongo Rémi

    2013-03-01

    Experience-based analysis (EBA) refers to a set of safety-management practices consisting of detecting, analyzing, and correcting the individual, material, and organizational causal factors of accidents in order to prevent their reoccurrence. Unfortunately, these practices do not always garner the adherence of employees. This article presents a study that examines the impact of risk perceptions on agents' motivation to participate in EBA in various production sectors. The study was conducted at two sites, a chemical factory and a nuclear power plant, by means of a questionnaire administered to 302 employees. The results indicated that the feeling of control was not only positively linked to the feeling of invulnerability, but that these two factors were negatively linked to risk perception. In addition, the actors in both production sectors were more motivated to participate in EBA of accidents linked to the core processes of their industry (which were more accurately perceived) than in EBA of ordinary accidents (accidents not specific to chemical or nuclear processes). Moreover, the agents' feeling of invulnerability and feeling of control both reduced EBA motivation for ordinary accidents to a greater extent than for chemical and radiation-related accidents. Recommendations are made in view of encouraging agents to get more involved in EBA.

  15. Predicting Successful Treatment Outcome of Web-Based Self-help for Problem Drinkers: Secondary Analysis From a Randomized Controlled Trial

    PubMed Central

    Kramer, Jeannet; Keuken, Max; Smit, Filip; Schippers, Gerard; Cuijpers, Pim

    2008-01-01

    Background Web-based self-help interventions for problem drinking are coming of age. They have shown promising results in terms of cost-effectiveness, and they offer opportunities to reach out on a broad scale to problem drinkers. The question now is whether certain groups of problem drinkers benefit more from such Web-based interventions than others. Objective We sought to identify baseline, client-related predictors of the effectiveness of Drinking Less, a 24/7, free-access, interactive, Web-based self-help intervention without therapist guidance for problem drinkers who want to reduce their alcohol consumption. The intervention is based on cognitive-behavioral and self-control principles. Methods We conducted secondary analysis of data from a pragmatic randomized trial with follow-up at 6 and 12 months. Participants (N = 261) were adult problem drinkers in the Dutch general population with a weekly alcohol consumption above 210 g of ethanol for men or 140 g for women, or consumption of at least 60 g (men) or 40 g (women) one or more days a week over the past 3 months. Six baseline participant characteristics were designated as putative predictors of treatment response: (1) gender, (2) education, (3) Internet use competence (sociodemographics), (4) mean weekly alcohol consumption, (5) prior professional help for alcohol problems (level of problem drinking), and (6) participants’ expectancies of Web-based interventions for problem drinking. Intention-to-treat (ITT) analyses, using last-observation-carried-forward (LOCF) data, and regression imputation (RI) were performed to deal with loss to follow-up. Statistical tests for interaction terms were conducted and linear regression analysis was performed to investigate whether the participants’ characteristics as measured at baseline predicted positive treatment responses at 6- and 12-month follow-ups. Results At 6 months, prior help for alcohol problems predicted a small, marginally significant positive treatment

  16. Internet-Based Cognitive Behavioral Therapy for Insomnia (ICBT-i) Improves Comorbid Anxiety and Depression-A Meta-Analysis of Randomized Controlled Trials.

    PubMed

    Ye, Yuan-Yuan; Zhang, Yuan-Feng; Chen, Jia; Liu, Juan; Li, Xun-Jun; Liu, Ya-Zhen; Lang, Ying; Lin, Ling; Yang, Xin-Ju; Jiang, Xiao-Jiang

    2015-01-01

    As the internet has become popularized in recent years, cognitive behavioral therapy for insomnia (CBT-i) has shifted from a face-to-face approach to delivery via the internet (internet-based CBT-i, ICBT-i). Several studies have investigated the effects of ICBT-i on comorbid anxiety and depression; however, the results remain inconclusive. Thus, a meta-analysis was conducted to determine the effects of ICBT-i on anxiety and depression. Electronic databases, including PubMed, EMBASE, PsycINFO and the Cochrane Library (throughout May 28, 2015), were systematically searched for randomized controlled trials (RCTs) of ICBT-i. Data were extracted from the qualified studies and pooled together. The standardized mean difference (SMD) and 95% confidence interval (95% CI) were calculated to assess the effects of ICBT-i on comorbid anxiety and depression. Nine records that included ten studies were ultimately qualified. The effect sizes (ESs) were -0.35 [-0.46, -0.25] for anxiety and -0.36 [-0.47, -0.26] for depression, which were stable using a between-group or within-group comparison and suggest positive effects of ICBT-i on both comorbid disorders. Although positive results were identified in this meta-analysis, additional high-quality studies with larger sample sizes are needed in the future.

  17. Effectiveness of online mindfulness-based interventions in improving mental health: A review and meta-analysis of randomised controlled trials.

    PubMed

    Spijkerman, M P J; Pots, W T M; Bohlmeijer, E T

    2016-04-01

    Mindfulness-based interventions (MBIs) are increasingly being delivered through the Internet. Whereas numerous meta-analyses have investigated the effectiveness of face-to-face MBIs in the context of mental health and well-being, thus far a quantitative synthesis of the effectiveness of online MBIs is lacking. The aim of this meta-analysis was to estimate the overall effects of online MBIs on mental health. Fifteen randomised controlled trials were included in this study. A random effects model was used to compute pre-post between-group effect sizes, and the study quality of each of the included trials was rated. Results showed that online MBIs have a small but significant beneficial impact on depression (g=0.29), anxiety (g=0.22), well-being (g=0.23) and mindfulness (g=0.32). The largest effect was found for stress, with a moderate effect size (g=0.51). For stress and mindfulness, exploratory subgroup analyses demonstrated significantly higher effect sizes for guided online MBIs than for unguided online MBIs. In addition, meta-regression analysis showed that effect sizes for stress were significantly moderated by the number of intervention sessions. Effect sizes, however, were not significantly related to study quality. The findings indicate that online MBIs have potential to contribute to improving mental health outcomes, particularly stress. Limitations, directions for future research and practical implications are discussed.

  18. Exposure to Ionizing Radiation during Dental X-Rays Is Not Associated with Risk of Developing Meningioma: A Meta-Analysis Based on Seven Case-Control Studies

    PubMed Central

    Xu, Ping; Luo, Hong; Huang, Guang-Lei; Yin, Xin-Hai; Luo, Si-Yang; Song, Ju-Kun

    2015-01-01

    Background Many observational studies have found that exposure to dental X-rays is associated with the risk of development of meningioma. However, these findings are inconsistent. We conducted a meta-analysis to assess the relationship between exposure to dental X-rays and the risk of development of meningioma. Methods The PubMed and EMBASE databases were searched to identify eligible studies. Summary odds ratio (OR) estimates and 95% confidence intervals (95% CIs) were used to compute the risk of meningioma development according to heterogeneity. Subgroup and sensitivity analyses were performed to further explore the potential heterogeneity. Finally, publication bias was assessed. Results Seven case-control studies involving 6,174 patients and 19,459 controls were included in the meta-analysis. Neither exposure to dental X-rays nor performance of full-mouth panorex X-rays was associated with an increased risk of development of meningioma (overall: OR, 0.97; 95% CI, 0.70–1.32; dental X-rays: OR, 1.05; 95% CI, 0.89–1.25; panorex X-rays: OR, 1.01; 95% CI, 0.76–1.34). However, exposure to bitewing X-rays was associated with a slightly increased risk of development of meningioma (OR, 1.73; 95% CI, 1.28–2.34). Similar results were obtained in the subgroup and sensitivity analyses. Little evidence of publication bias was observed. Conclusion Based on the currently limited data, there is no association between exposure to dental X-rays and the risk of development of meningioma. However, these results should be cautiously interpreted because of the heterogeneity among studies. Additional large, high-quality clinical trials are needed to evaluate the association between exposure to dental X-rays and the risk of development of meningioma. PMID:25658814

  19. Exposure to ionizing radiation during dental X-rays is not associated with risk of developing meningioma: a meta-analysis based on seven case-control studies.

    PubMed

    Xu, Ping; Luo, Hong; Huang, Guang-Lei; Yin, Xin-Hai; Luo, Si-Yang; Song, Ju-Kun

    2015-01-01

    Many observational studies have found that exposure to dental X-rays is associated with the risk of development of meningioma. However, these findings are inconsistent. We conducted a meta-analysis to assess the relationship between exposure to dental X-rays and the risk of development of meningioma. The PubMed and EMBASE databases were searched to identify eligible studies. Summary odds ratio (OR) estimates and 95% confidence intervals (95% CIs) were used to compute the risk of meningioma development according to heterogeneity. Subgroup and sensitivity analyses were performed to further explore the potential heterogeneity. Finally, publication bias was assessed. Seven case-control studies involving 6,174 patients and 19,459 controls were included in the meta-analysis. Neither exposure to dental X-rays nor performance of full-mouth panorex X-rays was associated with an increased risk of development of meningioma (overall: OR, 0.97; 95% CI, 0.70-1.32; dental X-rays: OR, 1.05; 95% CI, 0.89-1.25; panorex X-rays: OR, 1.01; 95% CI, 0.76-1.34). However, exposure to bitewing X-rays was associated with a slightly increased risk of development of meningioma (OR, 1.73; 95% CI, 1.28-2.34). Similar results were obtained in the subgroup and sensitivity analyses. Little evidence of publication bias was observed. Based on the currently limited data, there is no association between exposure to dental X-rays and the risk of development of meningioma. However, these results should be cautiously interpreted because of the heterogeneity among studies. Additional large, high-quality clinical trials are needed to evaluate the association between exposure to dental X-rays and the risk of development of meningioma.

  20. A randomised controlled trial and mediation analysis of the ‘Healthy Habits’, telephone-based dietary intervention for preschool children

    PubMed Central

    2013-01-01

    Background Consumption of non-core foods in childhood is associated with excessive weight gain in childhood. Parents play a vital role in establishing healthy diet behaviours in young children. The aim of this study was to assess the effectiveness of a telephone-based intervention in reducing child consumption of non-core foods, and to examine parent and home food environment mediators of change in child consumption. Methods The ‘Healthy Habits’ trial utilised a clustered randomised controlled design. Setting/participants Parents were recruited from 30 preschools (N = 394 participants, mean age 35.2±5.6 years). Parents randomized to the intervention group received four telephone contacts and print materials. Parents allocated to the control condition receive generic print materials only. Non-core food consumption was assessed using a validated child dietary questionnaire at baseline, 2 and 6 months post recruitment in 2010. Results The intervention was effective in reducing child consumption of non-core foods at 2 months (intention to treat analysis: z=-2.83, p<.01), however this effect was not maintained at 6 months. Structural equation modelling using 2 month data indicated that child access to non-core foods in the home and child feeding strategies mediated the effect of the intervention. Conclusion The telephone-based intervention shows promise in improving short term dietary behaviour in preschool age children, however further development is needed to sustain the effect in the long-term. Trial registration Australian Clinical Trials Registry: ACTRN12609000820202 PMID:23566360

  1. Diabetes mellitus and risk of prostate cancer: an updated meta-analysis based on 12 case-control and 25 cohort studies.

    PubMed

    Zhang, Fan; Yang, Yuan; Skrip, Laura; Hu, Dayi; Wang, Yang; Wong, Chunguang; Qiu, Jingfu; Lei, Han

    2012-12-01

    The association between diabetes and risk of prostate cancer has been investigated widely. However, study results remain inconsistent and contradictory. Using a meta-analytic approach, the present study explore the relationship incorporating more recent studies and provide more powerful evidence without the limitations of any individual study. Relevant studies were identified by searching Pubmed and the Cochrane Central Register of Controlled Trials through May 18, 2012. The strength of the relationship between diabetes mellitus and risk of prostate cancer was assessed using relative risk (RR). Either a fixed effects or random effects model was used to calculate the pooled RRs. Stratification analyses and sensitivity analyses were conducted, and publication bias was assessed by Egger's test and Begg's test. Twelve case-control studies involving 9,767 cases and 19,790 controls, and 25 cohort studies involving 118,825 cases were included. The person-years of follow-up ranged from 29,963 to 6,264,890 among included cohort studies. Diabetes was not significantly associated with incidence of prostate cancer in our analysis of case-control studies only (RR = 0.846, 95 % CI [0.710, 1.009]) or that of cohort studies only (RR = 0.925, 95 % CI [0.811, 1.054]). However, through subgroup analyses, statistically significant associations between diabetes and prostate cancer were found when considering population-based studies only (RR = 0.719, 95 % CI [0.637, 0.812]), cohort studies conducted in the United States (RR = 0.789, 95 % CI [0.727, 0.857]), and studies with follow-up of more than 5 years. Compared to risk of prostate cancer among people without diabetes, diabetic patients using insulin treatment experienced reduced incidence of prostate cancer in both case-control and cohort studies. The results suggest that diabetes mellitus is associated with decreased incidence of prostate cancer, specifically in the population of the United States. In addition, the time since onset

  2. CERAMIC: Case-Control Association Testing in Samples with Related Individuals, Based on Retrospective Mixed Model Analysis with Adjustment for Covariates

    PubMed Central

    Zhong, Sheng; McPeek, Mary Sara

    2016-01-01

    We consider the problem of genetic association testing of a binary trait in a sample that contains related individuals, where we adjust for relevant covariates and allow for missing data. We propose CERAMIC, an estimating equation approach that can be viewed as a hybrid of logistic regression and linear mixed-effects model (LMM) approaches. CERAMIC extends the recently proposed CARAT method to allow samples with related individuals and to incorporate partially missing data. In simulations, we show that CERAMIC outperforms existing LMM and generalized LMM approaches, maintaining high power and correct type 1 error across a wider range of scenarios. CERAMIC results in a particularly large power increase over existing methods when the sample includes related individuals with some missing data (e.g., when some individuals with phenotype and covariate information have missing genotype), because CERAMIC is able to make use of the relationship information to incorporate partially missing data in the analysis while correcting for dependence. Because CERAMIC is based on a retrospective analysis, it is robust to misspecification of the phenotype model, resulting in better control of type 1 error and higher power than that of prospective methods, such as GMMAT, when the phenotype model is misspecified. CERAMIC is computationally efficient for genomewide analysis in samples of related individuals of almost any configuration, including small families, unrelated individuals and even large, complex pedigrees. We apply CERAMIC to data on type 2 diabetes (T2D) from the Framingham Heart Study. In a genome scan, 9 of the 10 smallest CERAMIC p-values occur in or near either known T2D susceptibility loci or plausible candidates, verifying that CERAMIC is able to home in on the important loci in a genome scan. PMID:27695091

  3. Performance Analysis on Fault Tolerant Control System

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Belcastro, Christine

    2005-01-01

    In a fault tolerant control (FTC) system, a parameter varying FTC law is reconfigured based on fault parameters estimated by fault detection and isolation (FDI) modules. FDI modules require some time to detect fault occurrences in aero-vehicle dynamics. In this paper, an FTC analysis framework is provided to calculate the upper bound of an induced-L(sub 2) norm of an FTC system with existence of false identification and detection time delay. The upper bound is written as a function of a fault detection time and exponential decay rates and has been used to determine which FTC law produces less performance degradation (tracking error) due to false identification. The analysis framework is applied for an FTC system of a HiMAT (Highly Maneuverable Aircraft Technology) vehicle. Index Terms fault tolerant control system, linear parameter varying system, HiMAT vehicle.

  4. Diagnostic throughput factor analysis for en-route airspace and optimal aircraft trajectory generation based on capacity prediction and controller workload

    NASA Astrophysics Data System (ADS)

    Shin, Sanghyun

    Today's National Airspace System (NAS) is approaching its limit to efficiently cope with the increasing air traffic demand. Next Generation Air Transportation System (NextGen) with its ambitious goals aims to make the air travel more predictable with fewer delays, less time sitting on the ground and holding in the air to improve the performance of the NAS. However, currently the performance of the NAS is mostly measured using delay-based metrics which do not capture a whole range of important factors that determine the quality and level of utilization of the NAS. The factors affecting the performance of the NAS are themselves not well defined to begin with. To address these issues, motivated by the use of throughput-based metrics in many areas such as ground transportation, wireless communication and manufacturing, this thesis identifies the different factors which majorly affect the performance of the NAS as demand (split into flight cancellation and flight rerouting), safe separation (split into conflict and metering) and weather (studied as convective weather) through careful comparison with other applications and performing empirical sensitivity analysis. Additionally, the effects of different factors on the NAS's performance are quantitatively studied using real traffic data with the Future ATM Concepts Evaluation Tool (FACET) for various sectors and centers of the NAS on different days. In this thesis we propose a diagnostic tool which can analyze the factors that have greater responsibility for regions of poor and better performances of the NAS. Based on the throughput factor analysis for en-route airspace, it was found that weather and controller workload are the major factors that decrease the efficiency of the airspace. Also, since resources such as air traffic controllers, infrastructure and airspace are limited, it is becoming increasingly important to use the available resources efficiently. To alleviate the impact of the weather and controller

  5. Quality control, data base and gridded analysis products provided by the Global Precipitation Climatology Centre (GPCC) to serve the hydro-climatology community

    NASA Astrophysics Data System (ADS)

    Ziese, M.; Becker, A.; Schneider, U.; Meyer-Christoffer, A.; Finger, P.; Rudolf, B.

    2011-12-01

    Since its start in 1989 the Global Precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth's land-surface on the basis of in-situ measurements. Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The high spatio-temporal variability of precipitation requires a high density of measurement data. The GPCC receives the SYNOP and CLIMAT messages in near real-time via the WMO GTS. Core data source of the GPCC analyses are the data from station networks operated by the National Meteorological/Hydrological Services worldwide; data deliveries have been received from ca. 190 countries. The GPCC integrates also other global precipitation data collections (i.e. FAO, CRU and GHCN), as well as regional data sets and has recently started collection and analysis of daily data while keeping its other activities upright. As a result of these efforts the GPCC holds the worldwide largest and most comprehensive collection of precipitation data, which is continuously updated and extended. The acquired data sets are pre-checked and imported into a relational data base, thus allowing a cross-comparison of data from the different sources. Any time new data sets are imported to the data base the metadata in the input data set are compared to those already available. Since the beginning of 2009 the precipitation data to be imported is compared against a background statistic. Exceptional values are checked and either confirmed, corrected or excluded from the analyses. Near-real-time products are the 'First Guess Product' (created for early detection, e.g., drought monitoring) and 'Monitoring Product' (created on WCRP request and for merging to satellite data), both with a spatial resolution of 1°x1°. Only an automatic quality control runs during the generation of the 'First Guess Product', whereas the data base is

  6. Impact of Information Technology-Based Interventions for Type 2 Diabetes Mellitus on Glycemic Control: A Systematic Review and Meta-Analysis.

    PubMed

    Alharbi, Nouf Sahal; Alsubki, Nada; Jones, Simon; Khunti, Kamlesh; Munro, Neil; de Lusignan, Simon

    2016-11-25

    Information technology-based interventions are increasingly being used to manage health care. However, there is conflicting evidence regarding whether these interventions improve outcomes in people with type 2 diabetes. The objective of this study was to conduct a systematic review and meta-analysis of clinical trials, assessing the impact of information technology on changes in the levels of hemoglobin A1c (HbA1c) and mapping the interventions with chronic care model (CCM) elements. Electronic databases PubMed and EMBASE were searched to identify relevant studies that were published up until July 2016, a method that was supplemented by identifying articles from the references of the articles already selected using the electronic search tools. The study search and selection were performed by independent reviewers. Of the 1082 articles retrieved, 32 trials (focusing on a total of 40,454 patients) were included. A random-effects model was applied to estimate the pooled results. Information technology-based interventions were associated with a statistically significant reduction in HbA1c levels (mean difference -0.33%, 95% CI -0.40 to -0.26, P<.001). Studies focusing on electronic self-management systems demonstrated the largest reduction in HbA1c (0.50%), followed by those with electronic medical records (0.17%), an electronic decision support system (0.15%), and a diabetes registry (0.05%). In addition, the more CCM-incorporated the information technology-based interventions were, the more improvements there were in HbA1c levels. Information technology strategies combined with the other elements of chronic care models are associated with improved glycemic control in people with diabetes. No clinically relevant impact was observed on low-density lipoprotein levels and blood pressure, but there was evidence that the cost of care was lower.

  7. Impact of Information Technology–Based Interventions for Type 2 Diabetes Mellitus on Glycemic Control: A Systematic Review and Meta-Analysis

    PubMed Central

    Alharbi, Nouf Sahal; Alsubki, Nada; Jones, Simon; Khunti, Kamlesh; Munro, Neil

    2016-01-01

    Background Information technology–based interventions are increasingly being used to manage health care. However, there is conflicting evidence regarding whether these interventions improve outcomes in people with type 2 diabetes. Objective The objective of this study was to conduct a systematic review and meta-analysis of clinical trials, assessing the impact of information technology on changes in the levels of hemoglobin A1c (HbA1c) and mapping the interventions with chronic care model (CCM) elements. Methods Electronic databases PubMed and EMBASE were searched to identify relevant studies that were published up until July 2016, a method that was supplemented by identifying articles from the references of the articles already selected using the electronic search tools. The study search and selection were performed by independent reviewers. Of the 1082 articles retrieved, 32 trials (focusing on a total of 40,454 patients) were included. A random-effects model was applied to estimate the pooled results. Results Information technology–based interventions were associated with a statistically significant reduction in HbA1c levels (mean difference −0.33%, 95% CI −0.40 to −0.26, P<.001). Studies focusing on electronic self-management systems demonstrated the largest reduction in HbA1c (0.50%), followed by those with electronic medical records (0.17%), an electronic decision support system (0.15%), and a diabetes registry (0.05%). In addition, the more CCM-incorporated the information technology–based interventions were, the more improvements there were in HbA1c levels. Conclusions Information technology strategies combined with the other elements of chronic care models are associated with improved glycemic control in people with diabetes. No clinically relevant impact was observed on low-density lipoprotein levels and blood pressure, but there was evidence that the cost of care was lower. PMID:27888169

  8. The effects of school-based lifestyle interventions on body mass index and blood pressure: a multivariate multilevel meta-analysis of randomized controlled trials.

    PubMed

    Oosterhoff, M; Joore, M; Ferreira, I

    2016-11-01

    Primary prevention of childhood obesity and related hypertension is warrant given that both risk factors are intertwined and track into adulthood. This systematic review and meta-analysis assess the impact of school-based lifestyle interventions on children's body mass index (BMI) and blood pressure. We searched databases and prior reviews. Eligibility criteria were the following: randomized controlled trial design, evaluation of a school-based intervention, targeting children aged 4-12 years, reporting on BMI and/or related cardiovascular risk factors, reporting data on at least one follow-up moment. The effects on BMI, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were evaluated by means of univariate and multivariate three-level random effects models. A total of 85 RCTs (91 papers) were included in the meta-analyses. In univariate models, the pooled effects were -0.072 (95%CI: -0.106; -0.038) for BMI, -0.183 (95%CI: -0.288; -0.078) for SBP and -0.071 (95%CI: -0.185; 0.044) for DBP. In multivariate analyses, the pooled effects of interventions were -0.054 (95%CI: -0.131; 0.022) for BMI, -0.182 (95%CI: -0.266; -0.098) for SBP and -0.144 (95%CI: -0.230; -0.057) for DBP. Parental involvement accentuated the beneficial effects of interventions. School-based lifestyle prevention interventions result in beneficial changes in children's BMI and blood pressure, and the effects on the latter may be stronger than and accrue independently from those in the former.

  9. Switching from premixed insulin to glargine-based insulin regimen improves glycaemic control in patients with type 1 or type 2 diabetes: a retrospective primary care-based analysis

    PubMed Central

    Sharplin, Peter; Gordon, Jason; Peters, John R; Tetlow, Anthony P; Longman, Andrea J; McEwan, Philip

    2009-01-01

    Background Insulin glargine (glargine) and premixed insulins (premix) are alternative insulin treatments. This analysis evaluated glycaemic control in 528 patients with type 1 (n = 183) or type 2 (n = 345) diabetes, after switching from premix to a glargine-based regimen, using unselected general practice (GP) data. Methods Data for this retrospective observational analysis were extracted from a UK GP database (The Health Improvement Network). Patients were required to have at least 12 months of available data, before and after, switching from premix to a glargine-based regimen. The principal analysis was the change in HbA1c after 12 months of treatment with glargine; secondary analyses included change in weight, bolus usage and total daily insulin dose. Inconsistent reporting of hypoglycemic episodes precludes reliable assessment of this outcome. Multivariate analyses were used to adjust for baseline characteristics and confounding variables. Results Both cohorts showed significant reduction in mean HbA1c 12 months after the switch: by -0.67% (p < 0.001) in the type 1 cohort and by -0.53% (p < 0.001) in the type 2 cohort (adjusted data). The size of HbA1c improvement was positively correlated with baseline HbA1c; patients with a baseline HbA1c ≥ 10% had the greatest mean reduction in HbA1c, by -1.7% (p < 0.001) and -1.2% (p < 0.001), respectively. The proportion of patients receiving co-bolus prescriptions increased in the type 1 (mean 24.6% to 95.1%, p < 0.001) and type 2 (mean 16.2% to 73.9%, p < 0.001) cohorts. There was no significant change in weight in either cohort. Total mean insulin use increased in type 2 diabetes patients (from 0.67 ± 1.35 U/Kg to 0.88 ± 1.33 U/Kg, p < 0.001) with a slight decrease in type 1 diabetes patients (from 1.04 ± 2.51 U/Kg to 0.98 ± 2.58 U/Kg, p < 0.001). Conclusion In everyday practice, patients with type 1 or type 2 diabetes inadequately controlled by premix insulins experienced significant improvement in glycaemic

  10. Situation analysis of the National Comprehensive Cancer Control Program (2013) in the I. R. of Iran; assessment and recommendations based on the IAEA imPACT mission.

    PubMed

    Rouhollahi, Mohammad Reza; Mohagheghi, Mohammad Ali; Mohammadrezai, Narges; Ghiasvand, Reza; Ghanbari Motlagh, Ali; Harirchi, Iraj; Zendehdel, Kazem

    2014-04-01

    Iran was engaged in the Program of Action for Cancer Therapy (PACT) in 2012, and delegates from the International Atomic Energy Agency (IAEA), and the World Health Organization (WHO) evaluated the National Cancer Control Program (NCCP) status (the imPACT mission), based on which they provided recommendations for improvements of NCCP in the I.R. of Iran. We reported the results of this situational analysis and discussed the recommendations and their implication in the promotion of NCCP in the I.R. of Iran.  International delegates visited the I.R. of Iran and evaluated different aspects and capacities of NCCP in Iran. In addition, a Farsi version of the WHO/IAEA self-assessment tool was completed by local experts and stakeholders, including experts from different departments of the Ministry of Health and Medical Education (MOHME) and representatives from the National Cancer Research Network (NCRN). Following these evaluations, the PACT office provided recommendations for improving the NCCP in Iran. Almost all the recommendations were endorsed by MOHME. The PACT program provided 31 recommendations for improvement of NCCP in Iran in six categories, including planning, cancer registration and information, prevention, early detection, diagnosis and treatment, and palliative care. The most important recommendation was to establish a strong, multi-sectoral NCCP committee and develop an updated national cancer control program. The imPACT mission report provided a comprehensive view about the NCCP status in Iran. An appropriate response to these recommendations and filing the observed gaps will improve the NCCP status in the I.R. of Iran.

  11. Physical controls and patterns of recruitment on the Drôme River (SE France): An analysis based on a chronosequence of high resolution aerial imagery

    NASA Astrophysics Data System (ADS)

    Piegay, H.; Stella, J. C.; Raepple, B.

    2014-12-01

    Along with the recent recognition of the role of vegetation in influencing channel hydraulics, and thus fluvial morphology comes the need for scientific research on vegetation recruitment and its control factors. Flood disturbance is known to create a suitable physical template for the establishment of woody pioneers. Sapling recruitment patterns and underlying physical controls were investigated on a 5 km braided reach of the Drôme River in South-eastern France, following the 2003 50-year flood event. The approach was based on the analysis of a chronosequence of high resolution aerial images acquired yearly between 2005 and 2011, complemented by airborne LiDAR data and field observations. The study highlights how physical complexity induced by natural variations in hydro-climatic and consequently hydro-geomorphic conditions facilitates variable patterns of recruitment. The initial post-flood vegetative units, which covered up to 10% of the total active channel area in 2005, was seen to double within six years. The variability of hydro-climatic conditions was reflected in the temporal and spatial patterns of recruitment, with a pronounced peak of vegetation expansion in 2007 and a decreasing trend following higher flows in 2009. Recruitment was further seen to be sustained in a variety of geomorphic units, which showed different probabilities and patterns of recruitment. Active channels were the prominent geomorphic unit in terms of total biomass development, while in-channel wood units showed the highest probability for recruitment. Vegetation recruitment understanding is becoming crucial for predicting fluvial system evolution in different hydroclimatic contexts. Applied, these findings may contribute to improve efforts made in the field of flood risk management, as well as restoration planning.

  12. An Artificial Neural Network Based Analysis of Factors Controlling Particle Size in a Virgin Coconut Oil-Based Nanoemulsion System Containing Copper Peptide.

    PubMed

    Samson, Shazwani; Basri, Mahiran; Fard Masoumi, Hamid Reza; Abdul Malek, Emilia; Abedi Karjiban, Roghayeh

    2016-01-01

    A predictive model of a virgin coconut oil (VCO) nanoemulsion system for the topical delivery of copper peptide (an anti-aging compound) was developed using an artificial neural network (ANN) to investigate the factors that influence particle size. Four independent variables including the amount of VCO, Tween 80: Pluronic F68 (T80:PF68), xanthan gum and water were the inputs whereas particle size was taken as the response for the trained network. Genetic algorithms (GA) were used to model the data which were divided into training sets, testing sets and validation sets. The model obtained indicated the high quality performance of the neural network and its capability to identify the critical composition factors for the VCO nanoemulsion. The main factor controlling the particle size was found out to be xanthan gum (28.56%) followed by T80:PF68 (26.9%), VCO (22.8%) and water (21.74%). The formulation containing copper peptide was then successfully prepared using optimum conditions and particle sizes of 120.7 nm were obtained. The final formulation exhibited a zeta potential lower than -25 mV and showed good physical stability towards centrifugation test, freeze-thaw cycle test and storage at temperature 25°C and 45°C.

  13. An Artificial Neural Network Based Analysis of Factors Controlling Particle Size in a Virgin Coconut Oil-Based Nanoemulsion System Containing Copper Peptide

    PubMed Central

    Samson, Shazwani; Basri, Mahiran; Fard Masoumi, Hamid Reza; Abdul Malek, Emilia; Abedi Karjiban, Roghayeh

    2016-01-01

    A predictive model of a virgin coconut oil (VCO) nanoemulsion system for the topical delivery of copper peptide (an anti-aging compound) was developed using an artificial neural network (ANN) to investigate the factors that influence particle size. Four independent variables including the amount of VCO, Tween 80: Pluronic F68 (T80:PF68), xanthan gum and water were the inputs whereas particle size was taken as the response for the trained network. Genetic algorithms (GA) were used to model the data which were divided into training sets, testing sets and validation sets. The model obtained indicated the high quality performance of the neural network and its capability to identify the critical composition factors for the VCO nanoemulsion. The main factor controlling the particle size was found out to be xanthan gum (28.56%) followed by T80:PF68 (26.9%), VCO (22.8%) and water (21.74%). The formulation containing copper peptide was then successfully prepared using optimum conditions and particle sizes of 120.7 nm were obtained. The final formulation exhibited a zeta potential lower than -25 mV and showed good physical stability towards centrifugation test, freeze-thaw cycle test and storage at temperature 25°C and 45°C. PMID:27383135

  14. Statistical quality control through overall vibration analysis

    NASA Astrophysics Data System (ADS)

    Carnero, M. a. Carmen; González-Palma, Rafael; Almorza, David; Mayorga, Pedro; López-Escobar, Carlos

    2010-05-01

    of predictive variables (high-frequency vibration displacements) that are sensible to the processes setup and the quality of the products obtained. Based on the result of this overall vibration analysis, a second paper will analyse self-induced vibration spectrums in order to define limit vibration bands, controllable every cycle or connected to permanent vibration-monitoring systems able to adjust sensible process variables identified by ANOVA, once the vibration readings exceed established quality limits.

  15. Effectiveness of Short-Term Inpatient Psychotherapy Based on Transactional Analysis With Patients With Personality Disorders: A Matched Control Study Using Propensity Score.

    PubMed

    Horn, Eva K; Verheul, Roel; Thunnissen, Moniek; Delimon, Jos; Soons, Mirjam; Meerman, Anke M M A; Ziegler, Uli M; Rossum, Bert V; Andrea, Helene; Stijnen, Theo; Emmelkamp, Paul M G; Busschbach, Jan J V

    2015-10-01

    Controlled studies on the effectiveness of inpatient psychotherapy with patients with personality disorders (PD) are rare. This study aims to compare 3-month short-term inpatient psychotherapy based on transactional analysis (STIP-TA) with other psychotherapies (OP) up to 36-month follow-up. PD patients treated with STIP-TA were matched with OP patients using the propensity score. The primary outcome measure was general psychiatric symptomatology; secondary outcomes were psychosocial functioning and quality of life. In 67 pairs of patients, both STIP-TA and OP showed large symptomatic and functional improvements. However, STIP-TA patients showed more symptomatic improvement at all time points compared to OP patients. At 36 months, 68% of STIP-TA patients were symptomatically recovered compared to 48% of OP patients. STIP-TA outperformed OP in terms of improvements in general psychiatric symptomatology and quality of life. Superiority of STIP-TA was most pronounced at 12-month follow-up, but remained intact over the course of the 3-year follow-up.

  16. Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings.

    PubMed

    Hahn, Andreas; Lang, Michael; Stuckart, Claudia

    2016-11-01

    The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component.This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied.Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive.Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.

  17. Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings

    PubMed Central

    Hahn, Andreas; Lang, Michael; Stuckart, Claudia

    2016-01-01

    Abstract The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable. PMID:27828871

  18. New Conclusions Regarding Comparison of Sevelamer and Calcium-Based Phosphate Binders in Coronary-Artery Calcification for Dialysis Patients: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Li, Shaomin; Chen, Yanbing; Wang, Yanni; Lou, Tanqi

    2015-01-01

    Background Sevelamer hydrochloride is used widely, but its impact upon cardiovascular calcification, cardiovascular mortality, all-cause mortality and hospitalization is not known. Outcomes Primary outcome was cardiovascular calcification (coronary artery calcification scores (CACS) and aortic calcification scores (ACS)). Secondary outcomes were serum characteristics, hospitalization, cardiovascular mortality and all-cause mortality. Risk ratio (RR), mean differences and standard mean difference with 95% confidence intervals (CIs) were pooled using random- or fixed-effects models. Results We identified 31 studies (on 23 randomized controlled trials with 4395 participants). An analysis pooling showed a significant decrease in serum levels of phosphate with calcium-based phosphate binders (CBPBs) by 0.17 mg/dL [mean difference (MD), 95% CI, 0.03, 0.31] than sevelamer. A significant difference in the change of CACS by –102.66 [MD: 95% CI, –159.51, –45.80] and ACS by –1008.73 [MD, 95% CI, –1664.75, –352.72] between sevelamer and CBPBs was observed. Prevalence of hypercalcemia (serum levels of calcium >10.2–10.5 mg/dL and >11.0 mg/dL) was significantly smaller for sevelamer (RR = 0.44, 95% CI, 0.33, 0.58; RR = 0.24, 95% CI, 0.14, 0.40). No significant difference was found in hospitalization, all-cause mortality or cardiovascular mortality. Conclusions This meta-analysis suggests that sevelamer benefits dialysis patients in terms of CACS, ACS and hypercalcemia. PMID:26230677

  19. Knowledge based imaging for terrain analysis

    NASA Technical Reports Server (NTRS)

    Holben, Rick; Westrom, George; Rossman, David; Kurrasch, Ellie

    1992-01-01

    A planetary rover will have various vision based requirements for navigation, terrain characterization, and geological sample analysis. In this paper we describe a knowledge-based controller and sensor development system for terrain analysis. The sensor system consists of a laser ranger and a CCD camera. The controller, under the input of high-level commands, performs such functions as multisensor data gathering, data quality monitoring, and automatic extraction of sample images meeting various criteria. In addition to large scale terrain analysis, the system's ability to extract useful geological information from rock samples is illustrated. Image and data compression strategies are also discussed in light of the requirements of earth bound investigators.

  20. Individualized dual antiplatelet therapy based on platelet function testing in patients undergoing percutaneous coronary intervention: a meta-analysis of randomized controlled trials.

    PubMed

    Zhou, Yijiang; Wang, Yanwei; Wu, Yutao; Huang, Chaoyang; Yan, Hui; Zhu, Weiguo; Xu, Weiwei; Zhang, Li; Zhu, Jianhua

    2017-06-15

    High on-treatment platelet reactivity (HPR) represents a strong risk factor for thrombotic events after PCI. We aim to evaluate the efficacy and safety of individualizing intensified dual antiplatelet therapy (DAPT) in PCI-treated patients with HPR based on platelet function testing (PFT). Electronic databases were searched for randomized control trials that reported the clinical outcomes of using an intensified antiplatelet protocol with P2Y12 receptor inhibitor comparing with standard maintenance dose of clopidogrel on the basis of platelet function testing. Clinical endpoints were assessed. From 2005 to 2016, thirteen clinical studies comprising 7290 patients were included for analysis. Compared with standard antiplatelet therapy with clopidogrel, the intensified protocol based on platelet function testing was associated with a significant reduction in major adverse cardiovascular events (RR:0.55, 95% CI: 0.36-0.84, p = 0.005), cardiovascular death (RR:0.60, 95% CI: 0.38-0.96, p = 0.03), stent thrombosis (RR:0.58, 95% CI: 0.36-0.93, p = 0.02) and target vessel revascularization (RR:0.33, 95% CI: 0.14-0.76, p = 0.009). No significant difference was found in the rate of bleeding events between intensified and standard protocol. Compared with standard clopidogrel therapy, individualized intensified antiplatelet therapy on the basis of platelet reactivity testing reduces the incidence of cardiovascular events in patient undergoing PCI, without increasing the risk of bleeding.

  1. Adaptable state based control system

    NASA Technical Reports Server (NTRS)

    Rasmussen, Robert D. (Inventor); Dvorak, Daniel L. (Inventor); Gostelow, Kim P. (Inventor); Starbird, Thomas W. (Inventor); Gat, Erann (Inventor); Chien, Steve Ankuo (Inventor); Keller, Robert M. (Inventor)

    2004-01-01

    An autonomous controller, comprised of a state knowledge manager, a control executor, hardware proxies and a statistical estimator collaborates with a goal elaborator, with which it shares common models of the behavior of the system and the controller. The elaborator uses the common models to generate from temporally indeterminate sets of goals, executable goals to be executed by the controller. The controller may be updated to operate in a different system or environment than that for which it was originally designed by the replacement of shared statistical models and by the instantiation of a new set of state variable objects derived from a state variable class. The adaptation of the controller does not require substantial modification of the goal elaborator for its application to the new system or environment.

  2. Designing a risk-based surveillance program for Mycobacterium avium ssp. paratuberculosis in Norwegian dairy herds using multivariate statistical process control analysis.

    PubMed

    Whist, A C; Liland, K H; Jonsson, M E; Sæbø, S; Sviland, S; Østerås, O; Norström, M; Hopp, P

    2014-11-01

    Surveillance programs for animal diseases are critical to early disease detection and risk estimation and to documenting a population's disease status at a given time. The aim of this study was to describe a risk-based surveillance program for detecting Mycobacterium avium ssp. paratuberculosis (MAP) infection in Norwegian dairy cattle. The included risk factors for detecting MAP were purchase of cattle, combined cattle and goat farming, and location of the cattle farm in counties containing goats with MAP. The risk indicators included production data [culling of animals >3 yr of age, carcass conformation of animals >3 yr of age, milk production decrease in older lactating cows (lactations 3, 4, and 5)], and clinical data (diarrhea, enteritis, or both, in animals >3 yr of age). Except for combined cattle and goat farming and cattle farm location, all data were collected at the cow level and summarized at the herd level. Predefined risk factors and risk indicators were extracted from different national databases and combined in a multivariate statistical process control to obtain a risk assessment for each herd. The ordinary Hotelling's T(2) statistic was applied as a multivariate, standardized measure of difference between the current observed state and the average state of the risk factors for a given herd. To make the analysis more robust and adapt it to the slowly developing nature of MAP, monthly risk calculations were based on data accumulated during a 24-mo period. Monitoring of these variables was performed to identify outliers that may indicate deviance in one or more of the underlying processes. The highest-ranked herds were scattered all over Norway and clustered in high-density dairy cattle farm areas. The resulting rankings of herds are being used in the national surveillance program for MAP in 2014 to increase the sensitivity of the ongoing surveillance program in which 5 fecal samples for bacteriological examination are collected from 25 dairy herds

  3. CATS-based Air Traffic Controller Agents

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.

    2002-01-01

    This report describes intelligent agents that function as air traffic controllers. Each agent controls traffic in a single sector in real time; agents controlling traffic in adjoining sectors can coordinate to manage an arrival flow across a given meter fix. The purpose of this research is threefold. First, it seeks to study the design of agents for controlling complex systems. In particular, it investigates agent planning and reactive control functionality in a dynamic environment in which a variety perceptual and decision making skills play a central role. It examines how heuristic rules can be applied to model planning and decision making skills, rather than attempting to apply optimization methods. Thus, the research attempts to develop intelligent agents that provide an approximation of human air traffic controller behavior that, while not based on an explicit cognitive model, does produce task performance consistent with the way human air traffic controllers operate. Second, this research sought to extend previous research on using the Crew Activity Tracking System (CATS) as the basis for intelligent agents. The agents use a high-level model of air traffic controller activities to structure the control task. To execute an activity in the CATS model, according to the current task context, the agents reference a 'skill library' and 'control rules' that in turn execute the pattern recognition, planning, and decision-making required to perform the activity. Applying the skills enables the agents to modify their representation of the current control situation (i.e., the 'flick' or 'picture'). The updated representation supports the next activity in a cycle of action that, taken as a whole, simulates air traffic controller behavior. A third, practical motivation for this research is to use intelligent agents to support evaluation of new air traffic control (ATC) methods to support new Air Traffic Management (ATM) concepts. Current approaches that use large, human

  4. Adjoint-based Aeroacoustic Control

    DTIC Science & Technology

    2006-05-01

    temperature To - 1/(y - 1) Table 1: Vectors used for different controls: F [fl f2 f 3 f4 T defined in (4); F’ = [fl’ f2 f3 f]’T defined in (15); A = [ 0 a; a...listed in table 1 for the different types of control considered. 4.2.3 Numerical methods The flow equations were solved numerically and without any...The F’ correspond- ing to the specific controls we consider are listed in table 1. With an inner product defined (c, d) c . d dxdt f cn(x, t)dn(x, t

  5. Analysis of Control Power in Controlled Remote State Preparation Schemes

    NASA Astrophysics Data System (ADS)

    Li, Xihan; Ghose, Shohini

    2017-03-01

    We quantify and analyze the controller's power in controlled remote state preparation schemes. Our analysis provides a lower bound on the control power required for controlled remote preparation of arbitrary D-dimensional states. We evaluate several existing controlled remote state preparation protocols and show that some proposed non-maximally entangled channels are not suitable for perfect controlled remote preparation of arbitrary quantum states from the controller's point of view. We find that for remotely preparing D-dimensional states, the entropy of each controller should be no less than log2 D bits. Our new criteria are not only useful for evaluating controlled remote state preparation schemes but can also be used for other controlled quantum communication schemes.

  6. Control-Volume Analysis Of Thrust-Augmenting Ejectors

    NASA Technical Reports Server (NTRS)

    Drummond, Colin K.

    1990-01-01

    New method of analysis of transient flow in thrust-augmenting ejector based on control-volume formulation of governing equations. Considered as potential elements of propulsion subsystems of short-takeoff/vertical-landing airplanes.

  7. Systematic Quality Control Analysis of LINCS Data

    PubMed Central

    Cheng, L

    2016-01-01

    The Library of Integrated Cellular Signatures (LINCS) project provides comprehensive transcriptome profiling of human cell lines before and after chemical and genetic perturbations. Its L1000 platform utilizes 978 landmark genes to infer the transcript levels of 14,292 genes computationally. Here we conducted the L1000 data quality control analysis by using MCF7, PC3, and A375 cell lines as representative examples. Before perturbations, a promising 80% correlation in transcriptome was observed between L1000‐ and Affymetrix HU133A‐platforms. After library‐based shRNA perturbations, a moderate 30% of differentially expressed genes overlapped between any two selected controls viral vectors using the L1000 platform. The mitogen‐activated protein kinase, vascular endothelial growth factor, and T‐cell receptor pathways were identified as the most significantly shared pathways between chemical and genetic perturbations in cancer cells. In conclusion, L1000 platform is reliable in assessing transcriptome before perturbation. Its response to perturbagens needs to be interpreted with caution. A quality control analysis pipeline of L1000 is recommended before addressing biological questions. PMID:27796074

  8. Model-Based Fault Tolerant Control

    NASA Technical Reports Server (NTRS)

    Kumar, Aditya; Viassolo, Daniel

    2008-01-01

    The Model Based Fault Tolerant Control (MBFTC) task was conducted under the NASA Aviation Safety and Security Program. The goal of MBFTC is to develop and demonstrate real-time strategies to diagnose and accommodate anomalous aircraft engine events such as sensor faults, actuator faults, or turbine gas-path component damage that can lead to in-flight shutdowns, aborted take offs, asymmetric thrust/loss of thrust control, or engine surge/stall events. A suite of model-based fault detection algorithms were developed and evaluated. Based on the performance and maturity of the developed algorithms two approaches were selected for further analysis: (i) multiple-hypothesis testing, and (ii) neural networks; both used residuals from an Extended Kalman Filter to detect the occurrence of the selected faults. A simple fusion algorithm was implemented to combine the results from each algorithm to obtain an overall estimate of the identified fault type and magnitude. The identification of the fault type and magnitude enabled the use of an online fault accommodation strategy to correct for the adverse impact of these faults on engine operability thereby enabling continued engine operation in the presence of these faults. The performance of the fault detection and accommodation algorithm was extensively tested in a simulation environment.

  9. Meta-analysis of high doses of ambroxol treatment for acute lung injury/acute respiratory distress syndrome based on randomized controlled trials.

    PubMed

    Wu, Xiangdong; Li, Suwei; Zhang, Jiuzhi; Zhang, Yongli; Han, Lili; Deng, Qiuming; Wan, Xianyao

    2014-11-01

    This study seeks to evaluate the potential benefits of high doses of ambroxol treatment for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) by conducting a meta-analysis based on randomized controlled trials (RCTs). We searched the Pubmed, Embase, China National Knowledge Infrastructure, and Wanfang databases through December 2013. Only RCTs evaluating high doses of ambroxol (≥15 mg/kg or 1000 mg/day) treatment for patients with ALI/ARDS were selected. We included 10 RCTs involving 508 patients. Adjuvant treatment with high doses of ambroxol increased PaO(2)/FiO(2) (weight mean differences [WMD] = 69.18, 95% confidence intervals [CI]: 41.71-96.65), PO(2) (WMD = 11.74, 95% CI: 8.50-14.99), and SaO(2) (WMD = 2.15, 95% CI: 1.60-2.71) compared with usual treatment. Treatment with high doses of ambroxol appeared to reduce serum tumor necrosis factor-α level (WMD -7.92 µg/L; 95% CI, -10.94 to -4.9) and interleukin-6 level (WMD = -20.65 µg/L, 95% CI: -24.74 to -16.55) and to increase serum superoxide dismutase level (WMD = 19.07 NU/mL, 95% CI: 6.16-31.97). The findings suggest that treatment with high doses of ambroxol appears to improve PaO(2)/FiO(2), PO(2), and SaO(2), and the benefits might be related to ambroxol's anti-oxidant and anti-inflammatory properties. © 2014, The American College of Clinical Pharmacology.

  10. A randomized controlled trial on the efficacy of mindfulness-based cognitive therapy and a group version of cognitive behavioral analysis system of psychotherapy for chronically depressed patients.

    PubMed

    Michalak, Johannes; Schultze, Martin; Heidenreich, Thomas; Schramm, Elisabeth

    2015-10-01

    Mindfulness-based cognitive therapy (MBCT) has recently been proposed as a treatment option for chronic depression. The cognitive behavioral analysis system of psychotherapy (CBASP) is the only approach specifically developed to date for the treatment of chronically depressed patients. The efficacy of MBCT plus treatment-as-usual (TAU), and CBASP (group version) plus TAU, was compared to TAU alone in a prospective, bicenter, randomized controlled trial. One hundred and six patients with a current DSM-IV defined major depressive episode and persistent depressive symptoms for more than 2 years were randomized to TAU only (N = 35), or to TAU with additional 8-week group therapy of either 8 sessions of MBCT (n = 36) or CBASP (n = 35). The primary outcome measure was the Hamilton Depression Rating Scale (24-item HAM-D, Hamilton, 1967) at the end of treatment. Secondary outcome measures were the Beck Depression Inventory (BDI; Beck, Steer, & Brown, 1996) and measures of social functioning and quality of life. In the overall sample as well as at 1 treatment site, MBCT was no more effective than TAU in reducing depressive symptoms, although it was significantly superior to TAU at the other treatment site. CBASP was significantly more effective than TAU in reducing depressive symptoms in the overall sample and at both treatment sites. Both treatments had only small to medium effects on social functioning and quality of life. Further studies should inquire whether the superiority of CBASP in this trial might be explained by the more active, problem-solving, and interpersonal focus of CBASP. (c) 2015 APA, all rights reserved).

  11. Analysis and Modeling of Practical Experiment on IP Traffic Control

    NASA Astrophysics Data System (ADS)

    Suzuki, Tadamichi; Ito, Jungo; Nakano, Kazushi; Miki, Tetsuya

    In this paper, we focus on a practical experiment concerning IP traffic engineering over Multi-Protocol Label Switching (MPLS), especially which features feedback control capabilities. We present control-theoretic analysis of the experimental results based on acquired knowledge of actual network behavior. Because stable automated control capabilities are key issues in IP traffic engineering, we model an IP traffic control system based on the resulting analysis. In addition, comparison between simulated network behavior and actual one shows this model to have a high degree of stability, with a high potential for application to real networks.

  12. Flight test trajectory control analysis

    NASA Technical Reports Server (NTRS)

    Walker, R.; Gupta, N.

    1983-01-01

    Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver.

  13. Evaluation of a web-based intervention to reduce antibiotic prescribing for LRTI in six European countries: quantitative process analysis of the GRACE/INTRO randomised controlled trial

    PubMed Central

    2013-01-01

    Background To reduce the spread of antibiotic resistance, there is a pressing need for worldwide implementation of effective interventions to promote more prudent prescribing of antibiotics for acute LRTI. This study is a process analysis of the GRACE/INTRO trial of a multifactorial intervention that reduced antibiotic prescribing for acute LRTI in six European countries. The aim was to understand how the interventions were implemented and to examine effects of the interventions on general practitioners’ (GPs’) and patients’ attitudes. Methods GPs were cluster randomised to one of three intervention groups or a control group. The intervention groups received web-based training in either use of the C-reactive protein (CRP) test, communication skills and use of a patient booklet, or training in both. GP attitudes were measured before and after the intervention using constructs from the Theory of Planned Behaviour and a Website Satisfaction Questionnaire. Effects of the interventions on patients were assessed by a post-intervention questionnaire assessing patient enablement, satisfaction with the consultation, and beliefs about the risks and need for antibiotics. Results GPs in all countries and intervention groups had very positive perceptions of the intervention and the web-based training, and felt that taking part had helped them to reduce prescribing. All GPs perceived reducing prescribing as more important and less risky following the intervention, and GPs in the communication groups reported increased confidence to reduce prescribing. Patients in the communication groups who received the booklet reported the highest levels of enablement and satisfaction and had greater awareness that antibiotics could be unnecessary and harmful. Conclusions Our findings suggest that the interventions should be broadly acceptable to both GPs and patients, as well as feasible to roll out more widely across Europe. There are also some indications that they could help to

  14. Component protection based automatic control

    SciTech Connect

    Otaduy, P J

    1992-03-01

    Control and safety systems as well as operation procedures are designed on the basis of critical process parameters limits. The expectation is that short and long term mechanical damage and process failures will be avoided by operating the plant within the specified constraints envelopes. In this paper, one of the Advanced Liquid Metal Reactor (ALMR) design duty cycles events is discussed to corroborate that the time has come to explicitly make component protection part of the control system. Component stress assessment and aging data should be an integral part of the control system. Then transient trajectory planning and operating limits could be aimed at minimizing component specific and overall plant component damage cost functions. The impact of transients on critical components could then be managed according to plant lifetime design goals. The need for developing methodologies for online transient trajectory planning and assessment of operating limits in order to facilitate the explicit incorporation of damage assessment capabilities to the plant control and protection systems is discussed. 12 refs.

  15. Five COX-2 gene polymorphisms and risk of breast cancer: an updated meta-analysis based on 19 case-control studies.

    PubMed

    Li, Qing; Liu, Liu; Liu, Yanling; Zhou, Huirong; Yang, Zhi; Yuan, Keng; Min, Weiping

    2015-01-01

    The correlationship between COX-2 gene polymorphisms and breast cancer has been wildly studied, but the results remain controversial. Hence, the present meta-analysis aimed to investigate the association between COX-2 SNPs (rs5275, rs20417, rs689466, rs5277, rs2206593) and risk of breast cancer. Data were collected from PubMed, Embase and China National Knowledge Infrastructure. Summary odds ratio (OR) with 95 % confidence interval (CI) was applied to assess the relationship. Heterogeneity test, sensitivity analysis and publication bias test were also performed. There were 17 articles that contained 19 studies in this research. Fourteen case-control studies with 15,007 breast cancer cases and 20,005 controls were concerning rs5275 polymorphism, and 8 case-control studies with 10,216 cases and 12,839 controls were about rs20417 polymorphism. Other three polymorphisms (rs689466, rs2206593, rs5277) were studied in 5, 3 and 3 studies, respectively. COX-2-rs20417 CC genotype was significantly associated with increased risk of breast cancer when comparing to G allele [ORs were 1.231 (1.050-1.444) for CC vs. GG, P = 0.01, 1.223 (1.045-1.432) for CC vs. G carrier, P = 0.01]. Furthermore, the results of the subgroup analysis by ethnicity suggested that C allele significantly contributed to the risk of breast cancer for Asians [1.459 (1.182-1.802) for GC vs. GG, 1.472 (1.201-1.805) for C carrier vs. GG]. However, no association was found for rs5275, rs689466, rs5277 and rs2206593 in all comparison modes. This meta-analysis indicated that the COX-2 rs20417 polymorphism contributed to genetic susceptibility of breast cancer. In contrast, COX-2 rs5275, rs689466, rs2206593 and rs5277 polymorphisms might be not associated with the risk of breast cancer.

  16. Genetic Algorithm based Decentralized PI Type Controller: Load Frequency Control

    NASA Astrophysics Data System (ADS)

    Dwivedi, Atul; Ray, Goshaidas; Sharma, Arun Kumar

    2016-12-01

    This work presents a design of decentralized PI type Linear Quadratic (LQ) controller based on genetic algorithm (GA). The proposed design technique allows considerable flexibility in defining the control objectives and it does not consider any knowledge of the system matrices and moreover it avoids the solution of algebraic Riccati equation. To illustrate the results of this work, a load-frequency control problem is considered. Simulation results reveal that the proposed scheme based on GA is an alternative and attractive approach to solve load-frequency control problem from both performance and design point of views.

  17. Knowledge-Based Image Analysis.

    DTIC Science & Technology

    1981-04-01

    UNCLASSIF1 ED ETL-025s N IIp ETL-0258 AL Ai01319 S"Knowledge-based image analysis u George C. Stockman Barbara A. Lambird I David Lavine Laveen N. Kanal...extraction, verification, region classification, pattern recognition, image analysis . 3 20. A. CT (Continue on rever.. d. It necessary and Identify by...UNCLgSTFTF n In f SECURITY CLASSIFICATION OF THIS PAGE (When Date Entered) .L1 - I Table of Contents Knowledge Based Image Analysis I Preface

  18. Association between IL-13 +1923C/T polymorphism and asthma risk: a meta-analysis based on 26 case-control studies

    PubMed Central

    Xu, Yueli; Li, Junjuan; Ding, Zhaolei; Li, Juan; Li, Bin; Yu, Zhengang

    2017-01-01

    Asthma is a serious and hereditary respiratory disorder affecting all age groups. Interleukin-13 (IL-13) is a central regulator of allergic inflammation. The purpose of the present study was to estimate the relationship between IL-13 +1923C/T polymorphism and asthma susceptibility. Relevant case-control studies published between January 2000 and July 2016 were searched in the online databases. Review Manage (RevMan) 5.3 was used to conduct the statistical analysis. The pooled odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate the strength of association. A total of 26 articles were retrieved, including 17642 asthma patients and 42402 controls. Overall, our results found that IL-13 +1923C/T polymorphism was significantly associated with increased risk of asthma under each genetic model (P<0.00001). Subgroup analysis by ethnicity showed that alleles and genotypes of this variant correlated with asthma among Asians and Caucasians, but only TT genotype under the homozygote model in Africans. When stratified by age group, this variant highly correlated with asthma in children and moderately in adults. Furthermore, the TT, CT and CC genotypes in asthma group were all significantly associated with increased IgE levels in sera of asthma patients when compared with controls. Our results suggested that IL-13 +1923C/T polymorphism contributed to the development of asthma. Further case-control studies with more ethnicities are still needed. PMID:28057889

  19. Membrane Based Thermal Control Development

    NASA Technical Reports Server (NTRS)

    Murdoch, Karen

    1997-01-01

    The investigation of the feasibility of using a membrane device as a water boiler for thermal control is reported. The membrane device permits water vapor to escape to the vacuum of space but prevents the loss of liquid water. The vaporization of the water provides cooling to the water loop. This type of cooling device would have application for various types of short duration cooling needs where expenditure of water is allowed and a low pressure source is available such as in space or on a planet's surface. A variety of membrane samples, both hydrophilic and hydrophobic, were purchased to test for this thermal control application. An initial screening test determined if the membrane could pose a sufficient barrier to maintain water against vacuum. Further testing compared the heat transfer performance of those membranes that passed the screening test.

  20. Bortezomib-thalidomide-based regimens improved clinical outcomes without increasing toxicity as induction treatment for untreated multiple myeloma: a meta-analysis of phase III randomized controlled trials.

    PubMed

    Huang, Hejing; Zhou, Lili; Peng, Lihui; Fu, Weijun; Zhang, Chunyang; Hou, Jian

    2014-09-01

    Novel agents thalidomide and bortezomib have significantly improved myeloma treatment. However, it remains unclear whether patients will benefit more from the combination therapy of these two agents. Our meta-analysis aims to compare the efficiency, and more importantly, the safety of bortezomib-thalidomide-based (VT-based) versus bortezomib-based or thalidomide-based (V-based/T-based) regimens as induction therapy in patients with previously untreated myeloma. Overall, five phase III RCTs including 1765 patients were identified. Compared with V-based or T-based regimens, VT-based regimens significantly improved CR (OR=2.22, 95% CI [1.44, 3.43]), ORR (OR=2.19, 95% CI [1.51, 3.19]) as well as PFS (HR=0.69, 95% CI [0.54, 0.88]), but not OS (HR=1.04, 95% CI [0.91, 1.19]). Notably, most expected side effects of bortezomib or thalidomide were comparable in both groups, including hematologic (anemia, neutropenia, thrombocytopenia), nonhematologic (peripheral neuropathy, deep venous thrombosis, infections, gastrointestinal events) side effects and discontinuation during or after induction therapy. These results suggest that combination of thalidomide and bortezomib might be a better first-line choice for patients with untreated myeloma.

  1. Cyanoacrylate Injection Versus Band Ligation in the Endoscopic Management of Acute Gastric Variceal Bleeding: Meta-Analysis of Randomized, Controlled Studies Based on the PRISMA Statement.

    PubMed

    Qiao, Weiguang; Ren, Yutang; Bai, Yang; Liu, Side; Zhang, Qiang; Zhi, Fachao

    2015-10-01

    The evidence for optimal endoscopic management of bleeding gastric varices is lacking. The clinical outcome is controversial in trials comparing cyanoacrylate injection and band ligation. To help guide endoscopic decisions regarding acute gastric variceal bleeding, a meta-analysis was conducted.Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and ScienceDirect were searched for all randomized controlled trials (RCTs) containing the 2 interventions. The main outcomes evaluated in the meta-analysis were active bleeding control, blood transfusion, rebleeding, recurrence of varices, complications, and survival.Three RCTs were identified, which included 194 patients with active gastric variceal bleeding from Taiwan and Romania. Active bleeding control was achieved in 46 of 49 (93.9%) patients in the cyanoacrylate injection group, compared with 35 of 44 (79.5%) in the band ligation group (P = 0.032), for a pooled odds ratio of 4.44 (95% confidence interval, 1.14-17.30). Rebleeding rate was comparable in type 2 gastroesophageal varices (GOV2) between the 2 interventions (35.7% vs 34.8%, P = 0.895), but cyanoacrylate injection seemed superior for reducing rebleeding rate in type 1 gastroesophageal varices (GOV1, 26.1% vs 47.7%, P = 0.035) and type 1 isolated gastric varices (IGV1, 17.6% vs 85.7%, P = 0.015). Cyanoacrylate injection was also superior in controlling recurrence of gastric varices to band ligation (36.0% vs 66.0%, P = 0.002). There was no difference in complications or mortality between the 2 interventions. The major limitation of this meta-analysis is the small number of studies/patients included.Compared with band ligation, injection cyanocrylate have an advantage in the control of acute gastric variceal bleeding, also with lower recurrence rate and rebleeding (except GOV2). The limited amount of studies included attenuates the strength of this meta-analysis; therefore, more high-quality RCTs are needed.

  2. Adherence to Internet-Based Mobile-Supported Stress Management: A Pooled Analysis of Individual Participant Data From Three Randomized Controlled Trials

    PubMed Central

    Lehr, Dirk; Berking, Matthias; Riper, Heleen; Cuijpers, Pim; Ebert, David Daniel

    2016-01-01

    Background Nonadherence to treatment is a prevalent issue in Internet interventions. Guidance from health care professionals has been found to increase treatment adherence rates in Internet interventions for a range of physical and mental disorders. Evaluating different guidance formats of varying intensity is important, particularly with respect to improvement of effectiveness and cost-effectiveness. Identifying predictors of nonadherence allows for the opportunity to better adapt Internet interventions to the needs of participants especially at risk for discontinuing treatment. Objective The goal of this study was to investigate the influence of different guidance formats (content-focused guidance, adherence-focused guidance, and administrative guidance) on adherence and to identify predictors of nonadherence in an Internet-based mobile-supported stress management intervention (ie, GET.ON Stress) for employees. Methods The data from the groups who received the intervention were pooled from three randomized controlled trials (RCTs) that evaluated the efficacy of the same Internet-based mobile-supported stress management intervention (N=395). The RCTs only differed in terms of the guidance format (content-focused guidance vs waitlist control, adherence-focused guidance vs waitlist control, administrative guidance vs waitlist control). Adherence was defined by the number of completed treatment modules (0-7). An ANOVA was performed to compare the adherence rates from the different guidance formats. Multiple hierarchical linear regression analysis was conducted to evaluate predictors of nonadherence, which included gender, age, education, symptom-related factors, and hope for improvement. Results In all, 70.5% (93/132) of the content-focused guidance sample, 68.9% (91/132) of the adherence-focused guidance sample, and 42.0% (55/131) of the participants in the administrative guidance sample completed all treatment modules. Guidance had a significant effect on treatment

  3. Adherence to Internet-Based Mobile-Supported Stress Management: A Pooled Analysis of Individual Participant Data From Three Randomized Controlled Trials.

    PubMed

    Zarski, Anna-Carlotta; Lehr, Dirk; Berking, Matthias; Riper, Heleen; Cuijpers, Pim; Ebert, David Daniel

    2016-06-29

    Nonadherence to treatment is a prevalent issue in Internet interventions. Guidance from health care professionals has been found to increase treatment adherence rates in Internet interventions for a range of physical and mental disorders. Evaluating different guidance formats of varying intensity is important, particularly with respect to improvement of effectiveness and cost-effectiveness. Identifying predictors of nonadherence allows for the opportunity to better adapt Internet interventions to the needs of participants especially at risk for discontinuing treatment. The goal of this study was to investigate the influence of different guidance formats (content-focused guidance, adherence-focused guidance, and administrative guidance) on adherence and to identify predictors of nonadherence in an Internet-based mobile-supported stress management intervention (ie, GET.ON Stress) for employees. The data from the groups who received the intervention were pooled from three randomized controlled trials (RCTs) that evaluated the efficacy of the same Internet-based mobile-supported stress management intervention (N=395). The RCTs only differed in terms of the guidance format (content-focused guidance vs waitlist control, adherence-focused guidance vs waitlist control, administrative guidance vs waitlist control). Adherence was defined by the number of completed treatment modules (0-7). An ANOVA was performed to compare the adherence rates from the different guidance formats. Multiple hierarchical linear regression analysis was conducted to evaluate predictors of nonadherence, which included gender, age, education, symptom-related factors, and hope for improvement. In all, 70.5% (93/132) of the content-focused guidance sample, 68.9% (91/132) of the adherence-focused guidance sample, and 42.0% (55/131) of the participants in the administrative guidance sample completed all treatment modules. Guidance had a significant effect on treatment adherence (F2,392=11.64, P<.001;

  4. Control of Origin of Sesame Oil from Various Countries by Stable Isotope Analysis and DNA Based Markers—A Pilot Study

    PubMed Central

    Horacek, Micha; Hansel-Hohl, Karin; Burg, Kornel; Soja, Gerhard; Okello-Anyanga, Walter; Fluch, Silvia

    2015-01-01

    The indication of origin of sesame seeds and sesame oil is one of the important factors influencing its price, as it is produced in many regions worldwide and certain provenances are especially sought after. We joined stable carbon and hydrogen isotope analysis with DNA based molecular marker analysis to study their combined potential for the discrimination of different origins of sesame seeds. For the stable carbon and hydrogen isotope data a positive correlation between both isotope parameters was observed, indicating a dominant combined influence of climate and water availability. This enabled discrimination between sesame samples from tropical and subtropical/moderate climatic provenances. Carbon isotope values also showed differences between oil from black and white sesame seeds from identical locations, indicating higher water use efficiency of plants producing black seeds. DNA based markers gave independent evidence for geographic variation as well as provided information on the genetic relatedness of the investigated samples. Depending on the differences in ambient environmental conditions and in the genotypic fingerprint, a combination of both analytical methods is a very powerful tool to assess the declared geographic origin. To our knowledge this is the first paper on food authenticity combining the stable isotope analysis of bio-elements with DNA based markers and their combined statistical analysis. PMID:25831054

  5. Control of origin of sesame oil from various countries by stable isotope analysis and DNA based markers--a pilot study.

    PubMed

    Horacek, Micha; Hansel-Hohl, Karin; Burg, Kornel; Soja, Gerhard; Okello-Anyanga, Walter; Fluch, Silvia

    2015-01-01

    The indication of origin of sesame seeds and sesame oil is one of the important factors influencing its price, as it is produced in many regions worldwide and certain provenances are especially sought after. We joined stable carbon and hydrogen isotope analysis with DNA based molecular marker analysis to study their combined potential for the discrimination of different origins of sesame seeds. For the stable carbon and hydrogen isotope data a positive correlation between both isotope parameters was observed, indicating a dominant combined influence of climate and water availability. This enabled discrimination between sesame samples from tropical and subtropical/moderate climatic provenances. Carbon isotope values also showed differences between oil from black and white sesame seeds from identical locations, indicating higher water use efficiency of plants producing black seeds. DNA based markers gave independent evidence for geographic variation as well as provided information on the genetic relatedness of the investigated samples. Depending on the differences in ambient environmental conditions and in the genotypic fingerprint, a combination of both analytical methods is a very powerful tool to assess the declared geographic origin. To our knowledge this is the first paper on food authenticity combining the stable isotope analysis of bio-elements with DNA based markers and their combined statistical analysis.

  6. Conflicts versus analytical redundancy relations: a comparative analysis of the model based diagnosis approach from the artificial intelligence and automatic control perspectives.

    PubMed

    Cordier, Marie-Odile; Dague, Philippe; Lévy, François; Montmain, Jacky; Staroswiecki, Marcel; Travé-Massuyès, Louise

    2004-10-01

    Two distinct and parallel research communities have been working along the lines of the model-based diagnosis approach: the fault detection and isolation (FDI) community and the diagnostic (DX) community that have evolved in the fields of automatic control and artificial intelligence, respectively. This paper clarifies and links the concepts and assumptions that underlie the FDI analytical redundancy approach and the DX consistency-based logical approach. A formal framework is proposed in order to compare the two approaches and the theoretical proof of their equivalence together with the necessary and sufficient conditions is provided.

  7. SPS flexible system control assessment analysis

    NASA Technical Reports Server (NTRS)

    Balas, M. J.

    1981-01-01

    Active control of the Satellite Power System (SPS0, a large mechanically flexible aerospace structure is addressed. The control algorithm is the principle component in the feedback link from sensors to actuators. An analysis of the interaction of the SPS structure and its active control system is presented.

  8. The association between the LRRK2 G2385R variant and the risk of Parkinson's disease: a meta-analysis based on 23 case-control studies.

    PubMed

    Xie, Cheng-Long; Pan, Jia-Lin; Wang, Wen-Wen; Zhang, Yu; Zhang, Su-Fang; Gan, Jing; Liu, Zhen-Guo

    2014-10-01

    Clinical diagnosis of Parkinson's disease (PD) is essential but misdiagnosis of PD-like diseases is quite common. LRRK2 G2385R variants have been extensively examined for the association to the risk of Parkinson's disease. However, results from different studies are inconsistent. The purpose of this meta-analysis was to assess the association between the LRRK2 G2385R variants and the risk of PD. A systematic literature search was performed for 6 databases up to January of 2014 to identify case-control studies involving LRRK2 G2385R variants and the risk of PD. A total of 12,915 cases and 12,451 controls in 23 case-control studies were included in this meta-analysis. The results indicated that the variant A allele carriers (GA + AA) increased risk of PD when compared with the homozygote GG (GA + AA vs. GG: OR = 2.4, 95 % CI = 1.97 to 2.92, P < 0.00001). In the subgroup analysis by ethnicity, increased risks were identified among Chinese (OR = 2.69, 95 % CI = 2.1-3.45, P < 0.00001) as well as in non-Chinese (OR = 2.17, 95 % CI 1.75-2.69, P < 0.00001). In the subgroup analysis by age of onset, significant associations were found in both later-onset PD (LOPD) and early-onset PD (EOPD) cases. And there was no significant difference of the allele frequency between patients with LOPD and EOPD (OR = 1.18, 95 % CI = 0.77-1.80, P = 0.45). Our results suggest that the LRRK2 G2385R variants contribute to the susceptibility of PD especially in Chinese PD. Meanwhile, it is possible that age is not the risk factor to facilitate G2385R gene mutation.

  9. Adaptive control based on retrospective cost optimization

    NASA Astrophysics Data System (ADS)

    Santillo, Mario A.

    This dissertation studies adaptive control of multi-input, multi-output, linear, time-invariant, discrete-time systems that are possibly unstable and nonminimum phase. We consider both gradient-based adaptive control as well as retrospective-cost-based adaptive control. Retrospective cost optimization is a measure of performance at the current time based on a past window of data and without assumptions about the command or disturbance signals. In particular, retrospective cost optimization acts as an inner loop to the adaptive control algorithm by modifying the performance variables based on the difference between the actual past control inputs and the recomputed past control inputs based on the current control law. We develop adaptive control algorithms that are effective for systems that are nonminimum phase. We consider discrete-time adaptive control since these control laws can be implemented directly in embedded code without requiring an intermediate discretization step. Furthermore, the adaptive controllers in this dissertation are developed under minimal modeling assumptions. In particular, the adaptive controllers require knowledge of the sign of the high-frequency gain and a sufficient number of Markov parameters to approximate the nonminimum-phase zeros (if any). No additional modeling information is necessary. The adaptive controllers presented in this dissertation are developed for full-state-feedback stabilization, static-output-feedback stabilization, as well as dynamic compensation for stabilization, command following, disturbance rejection, and model reference adaptive control. Lyapunov-based stability and convergence proofs are provided for special cases. We present numerical examples to illustrate the algorithms' effectiveness in handling systems that are unstable and/or nonminimum phase and to provide insight into the modeling information required for controller implementation.

  10. Extremely low-frequency electromagnetic fields exposure and female breast cancer risk: a meta-analysis based on 24,338 cases and 60,628 controls.

    PubMed

    Chen, Chunhai; Ma, Xiangyu; Zhong, Min; Yu, Zhengping

    2010-09-01

    Exposure to extremely low-frequency electromagnetic fields (ELF-EMF) has been suggested to increase female breast cancer risk; however, the data have been inconclusive. In order to derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, the Cochrane Library and Web of Science were searched. Crude ORs with 95% CIs were used to assess the strength of association between ELF-EMF exposure and female breast cancer risk. A total of 15 studies published over the period 2000 to 2009 including 24,338 cases and 60,628 controls were involved in this meta-analysis. The results showed no significant association between ELF-EMF exposure and female breast cancer risk in total analysis (OR = 0.988, 95% CI = 0.898-1.088) and in all the subgroup analyses by exposure modes, menopausal status, and estrogen receptor status. This result is in accordance with the previous meta-analysis carried out by Erren in 2000. In conclusion, this meta-analysis suggests that ELF-EMF exposure has no association with the susceptibility of female breast cancer.

  11. Controllability Analysis for Multirotor Helicopter Rotor Degradation and Failure

    NASA Astrophysics Data System (ADS)

    Du, Guang-Xun; Quan, Quan; Yang, Binxian; Cai, Kai-Yuan

    2015-05-01

    This paper considers the controllability analysis problem for a class of multirotor systems subject to rotor failure/wear. It is shown that classical controllability theories of linear systems are not sufficient to test the controllability of the considered multirotors. Owing to this, an easy-to-use measurement index is introduced to assess the available control authority. Based on it, a new necessary and sufficient condition for the controllability of multirotors is derived. Furthermore, a controllability test procedure is approached. The proposed controllability test method is applied to a class of hexacopters with different rotor configurations and different rotor efficiency parameters to show its effectiveness. The analysis results show that hexacopters with different rotor configurations have different fault-tolerant capabilities. It is therefore necessary to test the controllability of the multirotors before any fault-tolerant control strategies are employed.

  12. IAC control system analysis development

    NASA Astrophysics Data System (ADS)

    Frisch, H. P.

    1982-03-01

    The MultiOptimal Differential Equation Language (MODEL) is described. It provides a means for generating numerical solutions to systems of differential equations using a digital computer. The notation of this language is similar to that usually used in describing physical systems by differential equations. Thus, the learning process is simplified, programming becomes easier, and debugging is more readily accomplished. Programs written in the MultiOptimal Differential Equation Language are machine translated into FORTRAN 4 code which is optimal in several respects. The interactive version of MODEL makes use of interactive system routines so that the user may observe the solution as it is being generated and interact with the program in a manner similar to that associated with analog simulation. The DISCOS-Control version of the MODEL simulation language is used to describe the control system for a plant which is modelled by the DISCOS program. DISCOS plant variables may be referenced in the control system description and all the sensor signals, coupling torques, momentum devices and external loads are automatically linked to the DISCOS plant model.

  13. A Network of Automatic Control Web-Based Laboratories

    ERIC Educational Resources Information Center

    Vargas, Hector; Sanchez Moreno, J.; Jara, Carlos A.; Candelas, F. A.; Torres, Fernando; Dormido, Sebastian

    2011-01-01

    This article presents an innovative project in the context of remote experimentation applied to control engineering education. Specifically, the authors describe their experience regarding the analysis, design, development, and exploitation of web-based technologies within the scope of automatic control. This work is part of an inter-university…

  14. A Network of Automatic Control Web-Based Laboratories

    ERIC Educational Resources Information Center

    Vargas, Hector; Sanchez Moreno, J.; Jara, Carlos A.; Candelas, F. A.; Torres, Fernando; Dormido, Sebastian

    2011-01-01

    This article presents an innovative project in the context of remote experimentation applied to control engineering education. Specifically, the authors describe their experience regarding the analysis, design, development, and exploitation of web-based technologies within the scope of automatic control. This work is part of an inter-university…

  15. Questionnaire-based analysis of infection prevention and control in healthcare facilities in Saudi Arabia in regards to Middle East Respiratory Syndrome.

    PubMed

    Rabaan, Ali A; Alhani, Hatem M; Bazzi, Ali M; Al-Ahmed, Shamsah H

    2017-02-16

    Effective implementation of infection prevention and control in healthcare facilities depends on training, awareness and compliance of healthcare workers. In Saudi Arabia recent significant hospital outbreaks, including Middle East Respiratory Syndrome Coronavirus (MERS-CoV), have resulted from lack of, or breakdown in, infection prevention and control procedures. This study was designed to assess attitudes to, and awareness of, infection prevention and control policies and guidelines among healthcare workers of different professions and institution types in Saudi Arabia. A questionnaire was administered to 607 healthcare workers including physicians (n=133), nurses (n=162), laboratory staff (n=233) and other staff (n=79) in government hospitals, private hospitals and poly clinics. Results were compared using Chi square analysis according to profession type, institution type, age group and nationality (Saudi or non-Saudi) to assess variability. Responses suggested that there are relatively high levels of uncertainty among healthcare workers across a range of infection prevention and control issues, including institution-specific issues, surveillance and reporting standards, and readiness and competence to implement policies and respond to outbreaks. There was evidence to suggest that staff in private hospitals and nurses were more confident than other staff types. Carelessness of healthcare workers was the top-cited factor contributing to causes of outbreaks (65.07% of total group), and hospital infrastructure and design was the top-cited factor contributing to spread of infection in the hospital (54.20%), followed closely by lack and shortage of staff (53.71%) and no infection control training program (51.73%). An electronic surveillance system was considered the most effective by staff (81.22%). We have identified areas of concern among healthcare workers in Saudi Arabia on infection prevention and control which vary between institutions and among different

  16. Quality control review: implementing a scientifically based quality control system.

    PubMed

    Westgard, James O; Westgard, Sten A

    2016-01-01

    This review focuses on statistical quality control in the context of a quality management system. It describes the use of a 'Sigma-metric' for validating the performance of a new examination procedure, developing a total quality control strategy, selecting a statistical quality control procedure and monitoring ongoing quality on the sigma scale. Acceptable method performance is a prerequisite to the design and implementation of statistical quality control procedures. Statistical quality control can only monitor performance, and when properly designed, alert analysts to the presence of additional errors that occur because of unstable performance. A new statistical quality control planning tool, called 'Westgard Sigma Rules,' provides a simple and quick way for selecting control rules and the number of control measurements needed to detect medically important errors. The concept of a quality control plan is described, along with alternative adaptations of a total quality control plan and a risk-based individualized quality control plan. Finally, the ongoing monitoring of analytic performance and test quality are discussed, including determination of measurement uncertainty from statistical quality control data collected under intermediate precision conditions and bias determined from proficiency testing/external quality assessment surveys. A new graphical tool, called the Sigma Quality Assessment Chart, is recommended for demonstrating the quality of current examination procedures on the sigma scale. © The Author(s) 2015.

  17. Control Strategy Scenarios for the Alien Lionfish Pterois volitans in Chinchorro Bank (Mexican Caribbean): Based on Semi-Quantitative Loop Analysis

    PubMed Central

    Ortiz, Marco; Rodriguez-Zaragoza, Fabián; Hermosillo-Nuñez, Brenda; Jordán, Ferenc

    2015-01-01

    Ecological and eco-social network models were constructed with different levels of complexity in order to represent and evaluate management strategies for controlling the alien species Pterois volitans in Chinchorro bank (Mexican Caribbean). Levins´s loop analysis was used as a methodological framework for assessing the local stability (considered as a component of sustainability) of the modeled management interventions represented by various scenarios. The results provided by models of different complexity (models 1 through 4) showed that a reduction of coral species cover would drive the system to unstable states. In the absence of the alien lionfish, the simultaneous fishing of large benthic epifaunal species, adult herbivorous fish and adult carnivorous fish could be sustainable only if the coral species present high levels of cover (models 2 and 3). Once the lionfish is added to the simulations (models 4 and 5), the analysis suggests that although the exploitation or removal of lionfish from shallow waters may be locally stable, it remains necessary to implement additional and concurrent human interventions that increase the holistic sustainability of the control strategy. The supplementary interventions would require the implementation of programs for: (1) the restoration of corals for increasing their cover, (2) the exploitation or removal of lionfish from deeper waters (decreasing the chance of source/sink meta-population dynamics) and (3) the implementation of bans and re-stocking programs for carnivorous fishes (such as grouper) that increase the predation and competition pressure on lionfish (i.e. biological control). An effective control management for the alien lionfish at Chinchorro bank should not be optimized for a single action plan: instead, we should investigate the concurrent implementation of multiple strategies. PMID:26114745

  18. Control Strategy Scenarios for the Alien Lionfish Pterois volitans in Chinchorro Bank (Mexican Caribbean): Based on Semi-Quantitative Loop Analysis.

    PubMed

    Ortiz, Marco; Rodriguez-Zaragoza, Fabián; Hermosillo-Nuñez, Brenda; Jordán, Ferenc

    2015-01-01

    Ecological and eco-social network models were constructed with different levels of complexity in order to represent and evaluate management strategies for controlling the alien species Pterois volitans in Chinchorro bank (Mexican Caribbean). Levins´s loop analysis was used as a methodological framework for assessing the local stability (considered as a component of sustainability) of the modeled management interventions represented by various scenarios. The results provided by models of different complexity (models 1 through 4) showed that a reduction of coral species cover would drive the system to unstable states. In the absence of the alien lionfish, the simultaneous fishing of large benthic epifaunal species, adult herbivorous fish and adult carnivorous fish could be sustainable only if the coral species present high levels of cover (models 2 and 3). Once the lionfish is added to the simulations (models 4 and 5), the analysis suggests that although the exploitation or removal of lionfish from shallow waters may be locally stable, it remains necessary to implement additional and concurrent human interventions that increase the holistic sustainability of the control strategy. The supplementary interventions would require the implementation of programs for: (1) the restoration of corals for increasing their cover, (2) the exploitation or removal of lionfish from deeper waters (decreasing the chance of source/sink meta-population dynamics) and (3) the implementation of bans and re-stocking programs for carnivorous fishes (such as grouper) that increase the predation and competition pressure on lionfish (i.e. biological control). An effective control management for the alien lionfish at Chinchorro bank should not be optimized for a single action plan: instead, we should investigate the concurrent implementation of multiple strategies.

  19. An adaptive pattern based nonlinear PID controller.

    PubMed

    Segovia, Juan Pablo; Sbarbaro, Daniel; Ceballos, Eric

    2004-04-01

    This paper presents a nonlinear proportional-integral-derivative (PID) controller, combining a pattern based adaptive algorithm to cope with the problem of tuning the controller, and an associative memory to store the parameters, according to different operating conditions. The simplicity of the algorithm enables its implementation in current programmable logic controller technology. Several real-time experiments, carried out in a pressurized tank, illustrate the performance of the proposed controller.

  20. Updated Meta-Analysis of Learner Control within Educational Technology

    ERIC Educational Resources Information Center

    Karich, Abbey C.; Burns, Matthew K.; Maki, Kathrin E.

    2014-01-01

    Giving a student control over their learning has theoretical and intuitive appeal, but its effects are neither powerful nor consistent in the empirical literature base. This meta-analysis updated previous meta-analytic research by Niemiec, Sikorski, and Walberg by studying the overall effectiveness of providing learner control within educational…

  1. Updated Meta-Analysis of Learner Control within Educational Technology

    ERIC Educational Resources Information Center

    Karich, Abbey C.; Burns, Matthew K.; Maki, Kathrin E.

    2014-01-01

    Giving a student control over their learning has theoretical and intuitive appeal, but its effects are neither powerful nor consistent in the empirical literature base. This meta-analysis updated previous meta-analytic research by Niemiec, Sikorski, and Walberg by studying the overall effectiveness of providing learner control within educational…

  2. Metronidazole amino acidum natrium combined with radiation in the treatment of nasopharyngeal carcinoma: A meta-analysis based on randomized controlled trials.

    PubMed

    Wei, Shengli; Xing, Yizhuo; Liu, Jixiang; Wang, Lin; Yang, Xiangli; Song, Fucun; Yang, Chunwei; Niu, Lin; Yang, Yang; Wu, Fei

    2015-10-01

    We performed this meta-analysis to assess the metronidazole amino acidum natrium combined with radiation in the treatment of nasopharyngeal carcinoma. Two reviewers independently reviewed the databases of PubMed and CNKI. The prospective, randomized, controlled trials of metronidazole amino acidum natrium combined with radiation versus radiotherapy alone in the treatment of nasopharyngeal carcinoma were included in this meta-analysis. The objective response rate (RR) of 1-, 3-, and 5-year survival rates were pooled by statistical software. The publication bias was evaluated by Begg's funnel plot. Sixteen prospective, randomized, controlled trials were finally included in this meta-analysis. The quality assessment showed that the method's quality was relatively poor. The pooled results showed that the metronidazole amino acidum natrium combined with radiation can significantly improve the objective RR for the primary lesion (RR = 1.37, 95% confidence interval [CI]: 1.23-1.53, P < 0.05) and neck metastasis lesion (RR = 1.36, 95% CI: 1.25-1.49, P < 0.05). For survival analysis, the combined treatment can significantly improve the 1-year survival (RR = 1.57, 95% CI: 1.28-1.93, P < 0.05), 3-year survival (RR = 1.23, 95% CI: 1.06-1.41, P < 0.05), and 5-year survival rates (RR = 1.27, 95% CI: 1.05-1.53, P < 0.05). Metronidazole amino acidum natrium combined with radiation can improve the objective RR and long-term survival compared to radiation therapy alone in the treatment of nasopharyngeal carcinoma.

  3. Pesticide Exposure as a Risk Factor for Myelodysplastic Syndromes: A Meta-Analysis Based on 1,942 Cases and 5,359 Controls

    PubMed Central

    Jin, Jie; Yu, Mengxia; Hu, Chao; Ye, Li; Xie, Lili; Jin, Jin; Chen, Feifei; Tong, Hongyan

    2014-01-01

    Objective Pesticide exposure has been linked to increased risk of cancer at several sites, but its association with risk of myelodysplastic syndromes (MDS) is still unclear. A meta-analysis of studies published through April, 2014 was performed to investigate the association of pesticide exposure with the risk of MDS. Methods Studies were identified by searching the Web of Science, Cochrane Library and PubMed databases. Summary odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated using random- or fixed-effect models. Results This meta-analysis included 11 case-control studies, all of which demonstrated a correlation between pesticide exposure and a statistically significant increased risk of MDS (OR = 1.95, 95% CI 1.23–3.09). In subgroup analyses, patients with pesticide exposure had increased risk of developing MDS if they were living in the Europe or Asia and had refractory anemia (RA) or RA with ringed sideroblasts (RARS). Moreover, in the analysis by specific pesticides, increased risk was associated with exposure to insecticides (OR = 1.71, 95% CI 1.22–2.40) but not exposure to herbicides or fungicides. Conclusion This meta-analysis supports the hypothesis that exposure to pesticides increases the risk of developing MDS. Further prospective cohort studies are warranted to verify the association and guide clinical practice in MDS prevention. PMID:25335083

  4. Development of a novel disturbance observer based fractional order PD controller for a gun control system.

    PubMed

    Gao, Qiang; Zheng, Liang; Chen, Jilin; Wang, Li; Hou, Yuanlong

    2014-01-01

    Motion control of gun barrels is an ongoing topic for the development of gun control equipment (GCE) with excellent performances. In this paper, a novel disturbance observer (DOB) based fractional order PD (FOPD) control strategy is proposed for the GCE. By adopting the DOB, the control system behaves as if it were the nominal closed-loop system in the absence of disturbances and uncertainties. The optimal control parameters of the FOPD are determined from the loop-shaping perspective, and the Q-filter of the DOB is deliberately designed with consideration of system robustness. The linear frame of the proposed control system will enable the analysis process more convenient. The disturbance rejection properties and the tracking performances of the control system are investigated by both numerical and experimental tests, the results demonstrate that the proposed DOB based FOPD control system is of more robustness, and it is much more suitable for the gun control system with strong nonlinearity and disturbance.

  5. State Analysis: A Control Architecture View of Systems Engineering

    NASA Technical Reports Server (NTRS)

    Rasmussen, Robert D.

    2005-01-01

    A viewgraph presentation on the state analysis process is shown. The topics include: 1) Issues with growing complexity; 2) Limits of common practice; 3) Exploiting a control point of view; 4) A glimpse at the State Analysis process; 5) Synergy with model-based systems engineering; and 6) Bridging the systems to software gap.

  6. MiR-146a rs2910164 polymorphism and head and neck carcinoma risk: a meta-analysis based on 10 case-control studies

    PubMed Central

    Xiang, Zhaolan; Song, Jue; Zhuo, Xianlu; Li, Qi; Zhang, Xueyuan

    2017-01-01

    Two recent meta-analyses have been conducted on the relationship between miR-146a polymorphism (rs2910164) and head and neck cancer (HNC) risk. However, they have yielded conflicting results. Hence, the aim of the present study was to conduct a quantitative updated meta-analysis addressing this subject. Eligible studies up to Sep 2016 were retrieved and screened from the bio-databases and then essential data were extracted for data analysis. Next, subgroup analyses on ethnicity, source of controls, sample size, and genotyping method were also carried out. As a result, a total of 9 publications involving 10 independent case-control studies were included. The overall data indicated a significant association between miR-146a rs2910164 polymorphism and HNC risk [C vs. G: odds ratio (OR) = 1.14; 95% confidence interval (CI) = 1.00–1.31; CC+CG vs. GG: OR=1.21; 95%CI=1.02-1.43]. Variant alleles of miR-146a rs2910164 may have a correlation with increased HNC risk. Future well-designed studies containing large sample sizes are needed to verify this result. PMID:27901485

  7. Active disturbance rejection control: methodology and theoretical analysis.

    PubMed

    Huang, Yi; Xue, Wenchao

    2014-07-01

    The methodology of ADRC and the progress of its theoretical analysis are reviewed in the paper. Several breakthroughs for control of nonlinear uncertain systems, made possible by ADRC, are discussed. The key in employing ADRC, which is to accurately determine the "total disturbance" that affects the output of the system, is illuminated. The latest results in theoretical analysis of the ADRC-based control systems are introduced.

  8. Flux-based active filter controller

    SciTech Connect

    Bhattacharya, S.; Divan, D.M.; Lorenz, R.D.; Veltman, A.

    1996-05-01

    This paper presents a synchronous frame flux-based control method for a parallel active filter application. The flux-based controller directly implements the inverter switchings in the synchronous reference frame by a hysteresis rule-based carrier-less pulse-width modulation (PWM) strategy to achieve high current bandwidth. This paper addresses the issues and impact on parallel active filtering requirements for utility interface of commonly used harmonic front-ends. The synchronous frame flux-based controller provides additional insights for harmonic current compensation requirements. Simulation results provide the validation of the flux-based active filter controller to meet IEEE Standard 519 recommended harmonic standards for large rated nonlinear loads under balanced and unbalanced supply conditions.

  9. Venous thromboembolism in adults screened for sickle cell trait: a population-based cohort study with nested case-control analysis.

    PubMed

    Little, Iain; Vinogradova, Yana; Orton, Elizabeth; Kai, Joe; Qureshi, Nadeem

    2017-03-29

    To determine whether sickle cell carriers ('sickle cell trait') have an increased risk of venous thromboembolism (VTE). Cohort study with nested case-control analysis. General population with data from 609 UK general practices in the Clinical Practice Research Datalink (CPRD). All individuals registered with a CPRD general practice between 1998 and 2013, with a medical record of screening for sickle cell between 18 and 75 years of age. Incidence of VTE per 10 000 person-years (PY) among sickle cell carriers and non-carriers; and adjusted OR for VTE among sickle cell carriers compared with non-carriers. We included 30 424 individuals screened for sickle cell, with a follow-up time of 179 503 PY, identifying 55 VTEs in 6758 sickle cell carriers and 125 VTEs in 23 666 non-carriers. VTE incidence among sickle cell carriers (14.9/10 000 PY; 95% CI 11.4 to 19.4) was significantly higher than non-carriers (8.8/10 000 PY; 95% CI 7.4 to 10.4). Restricting analysis to confirmed non-carriers was non-significant, but performed on a small sample. In the case-control analysis (180 cases matched to 1775 controls by age and gender), sickle cell carriers remained at increased risk of VTE after adjusting for body mass index, pregnancy, smoking status and ethnicity (OR 1.78, 95% CI 1.18 to 2.69, p=0.006), with the greatest risk for pulmonary embolism (PE) (OR 2.27, 95% CI 1.17 to 4.39, p=0.011). Although absolute numbers are small, in a general population screened for sickle cell, carriers have a higher incidence and risk of VTE, particularly PE, than non-carriers. Clinicians should be aware of this elevated risk in the clinical care of sickle cell carriers, or when discussing carrier screening, and explicitly attend to modifiable risk factors for VTE in these individuals. More complete primary care coding of carrier status could improve analysis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go

  10. Venous thromboembolism in adults screened for sickle cell trait: a population-based cohort study with nested case–control analysis

    PubMed Central

    Little, Iain; Vinogradova, Yana; Orton, Elizabeth; Kai, Joe; Qureshi, Nadeem

    2017-01-01

    Objective To determine whether sickle cell carriers (‘sickle cell trait’) have an increased risk of venous thromboembolism (VTE). Design Cohort study with nested case–control analysis. Setting General population with data from 609 UK general practices in the Clinical Practice Research Datalink (CPRD). Participants All individuals registered with a CPRD general practice between 1998 and 2013, with a medical record of screening for sickle cell between 18 and 75 years of age. Main outcomes measures Incidence of VTE per 10 000 person-years (PY) among sickle cell carriers and non-carriers; and adjusted OR for VTE among sickle cell carriers compared with non-carriers. Results We included 30 424 individuals screened for sickle cell, with a follow-up time of 179 503 PY, identifying 55 VTEs in 6758 sickle cell carriers and 125 VTEs in 23 666 non-carriers. VTE incidence among sickle cell carriers (14.9/10 000 PY; 95% CI 11.4 to 19.4) was significantly higher than non-carriers (8.8/10 000 PY; 95% CI 7.4 to 10.4). Restricting analysis to confirmed non-carriers was non-significant, but performed on a small sample. In the case–control analysis (180 cases matched to 1775 controls by age and gender), sickle cell carriers remained at increased risk of VTE after adjusting for body mass index, pregnancy, smoking status and ethnicity (OR 1.78, 95% CI 1.18 to 2.69, p=0.006), with the greatest risk for pulmonary embolism (PE) (OR 2.27, 95% CI 1.17 to 4.39, p=0.011). Conclusions Although absolute numbers are small, in a general population screened for sickle cell, carriers have a higher incidence and risk of VTE, particularly PE, than non-carriers. Clinicians should be aware of this elevated risk in the clinical care of sickle cell carriers, or when discussing carrier screening, and explicitly attend to modifiable risk factors for VTE in these individuals. More complete primary care coding of carrier status could improve analysis. PMID:28360235

  11. Efficient Quantum Private Communication Based on Dynamic Control Code Sequence

    NASA Astrophysics Data System (ADS)

    Cao, Zheng-Wen; Feng, Xiao-Yi; Peng, Jin-Ye; Zeng, Gui-Hua; Qi, Jin

    2017-04-01

    Based on chaos and quantum properties, we propose a quantum private communication scheme with dynamic control code sequence. The initial sequence is obtained via chaotic systems, and the control code sequence is derived by grouping, XOR and extracting. A shift cycle algorithm is designed to enable the dynamic change of control code sequence. Analysis shows that transmission efficiency could reach 100 % with high dynamics and security.

  12. Efficient Quantum Private Communication Based on Dynamic Control Code Sequence

    NASA Astrophysics Data System (ADS)

    Cao, Zheng-Wen; Feng, Xiao-Yi; Peng, Jin-Ye; Zeng, Gui-Hua; Qi, Jin

    2016-12-01

    Based on chaos and quantum properties, we propose a quantum private communication scheme with dynamic control code sequence. The initial sequence is obtained via chaotic systems, and the control code sequence is derived by grouping, XOR and extracting. A shift cycle algorithm is designed to enable the dynamic change of control code sequence. Analysis shows that transmission efficiency could reach 100 % with high dynamics and security.

  13. Diagnosis, Prevalence, Awareness, Treatment, Prevention, and Control of Hypertension in Cameroon: Protocol for a Systematic Review and Meta-Analysis of Clinic-Based and Community-Based Studies.

    PubMed

    Kuate Defo, Barthelemy; Mbanya, Jean Claude; Tardif, Jean-Claude; Ekundayo, Olugbemiga; Perreault, Sylvie; Potvin, Louise; Cote, Robert; Kengne, Andre Pascal; Choukem, Simeon Pierre; Assah, Felix; Kingue, Samuel; Richard, Lucie; Pongou, Roland; Frohlich, Katherine; Saji, Jude; Fournier, Pierre; Sobngwi, Eugene; Ridde, Valery; Dubé, Marie-Pierre; De Denus, Simon; Mbacham, Wilfred; Lafrance, Jean-Philippe; Nsagha, Dickson Shey; Mampuya, Warner; Dzudie, Anastase; Cloutier, Lyne; Zarowsky, Christina; Tanya, Agatha; Ndom, Paul; Hatem, Marie; Rey, Evelyne; Roy, Louise; Borgès Da Silva, Roxane; Dagenais, Christian; Todem, David; Weladji, Robert; Mbanya, Dora; Emami, Elham; Njoumemi, Zakariaou; Monnais, Laurence; Dubois, Carl-Ardy

    2017-05-29

    independently search, screen, extract data, and assess the quality of selected studies using suitable tools. Selected studies will be analyzed by narrative synthesis, meta-analysis, or both, depending on the nature of the data retrieved in line with the review objectives. This review is part of an ongoing research program on disease prevention and control in the context of the dual burden of communicable and noncommunicable diseases in Africa. The first results are expected in 2017. This review will provide a comprehensive assessment of the burden of hypertension and control measures that have been designed and implemented in Cameroon. Findings will form the knowledge base relevant to stakeholders across the health system and researchers who are involved in hypertension prevention and control in the community and clinic settings in Cameroon, as a yardstick for similar African countries. PROSPERO registration number: CRD42017054950; http://www.crd.york.ac.uk/PROSPERO/ display_record.asp?ID=CRD42017054950 (Archived by WebCite at http://www.webcitation.org/6qYSjt9Jc).

  14. Diagnosis, Prevalence, Awareness, Treatment, Prevention, and Control of Hypertension in Cameroon: Protocol for a Systematic Review and Meta-Analysis of Clinic-Based and Community-Based Studies

    PubMed Central

    Mbanya, Jean Claude; Tardif, Jean-Claude; Ekundayo, Olugbemiga; Perreault, Sylvie; Potvin, Louise; Cote, Robert; Kengne, Andre Pascal; Choukem, Simeon Pierre; Assah, Felix; Kingue, Samuel; Richard, Lucie; Pongou, Roland; Frohlich, Katherine; Saji, Jude; Fournier, Pierre; Sobngwi, Eugene; Ridde, Valery; Dubé, Marie-Pierre; De Denus, Simon; Mbacham, Wilfred; Lafrance, Jean-Philippe; Nsagha, Dickson Shey; Mampuya, Warner; Dzudie, Anastase; Cloutier, Lyne; Zarowsky, Christina; Tanya, Agatha; Ndom, Paul; Hatem, Marie; Rey, Evelyne; Roy, Louise; Borgès Da Silva, Roxane; Dagenais, Christian; Todem, David; Weladji, Robert; Mbanya, Dora; Emami, Elham; Njoumemi, Zakariaou; Monnais, Laurence; Dubois, Carl-Ardy

    2017-01-01

    reviewers of the team will independently search, screen, extract data, and assess the quality of selected studies using suitable tools. Selected studies will be analyzed by narrative synthesis, meta-analysis, or both, depending on the nature of the data retrieved in line with the review objectives. Results This review is part of an ongoing research program on disease prevention and control in the context of the dual burden of communicable and noncommunicable diseases in Africa. The first results are expected in 2017. Conclusions This review will provide a comprehensive assessment of the burden of hypertension and control measures that have been designed and implemented in Cameroon. Findings will form the knowledge base relevant to stakeholders across the health system and researchers who are involved in hypertension prevention and control in the community and clinic settings in Cameroon, as a yardstick for similar African countries. Trial Registration PROSPERO registration number: CRD42017054950; http://www.crd.york.ac.uk/PROSPERO/ display_record.asp?ID=CRD42017054950 (Archived by WebCite at http://www.webcitation.org/6qYSjt9Jc) PMID:28554882

  15. Avionics GPB Control System Analysis

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Gravity Probe B is a Satellite being developed by Lockheed Martin under NASA contract through MSFC and managed by Stanford University. The goal of the satellite experiment is to test the accuracy of drift predictions made using Einstein s General Theory of Relativity. The drift in the direction of the spin axes of 4 highly precise quartz spherical gyroscopes induced by motion in the earth s gravitational field will be measured over a year s duration with the known, non-relativistic effects removed. The expected angles of drift for a one year period are approximately 6.6 arcsec for drift in the orbit plane called geodetic drift and 0.033 arcsec of drift normal to the orbit plane called frame dragging. The aerodynamic drag force on the GPB Satellite is compensated by a translation control system. It is pointed at a guide star and maintained in spin at a rate to be selected in the range 0.1 - 1 rpm. The purpose of our task is to update the TREETOPS GPB spacecraft simulation and to assist MSFC in assessing the affect of Helium slosh dynamics on spacecraft pointing performance.

  16. Effects of exercise-based cardiac rehabilitation in patients after percutaneous coronary intervention: A meta-analysis of randomized controlled trials

    PubMed Central

    Yang, Xinyu; Li, Yanda; Ren, Xiaomeng; Xiong, Xingjiang; Wu, Lijun; Li, Jie; Wang, Jie; Gao, Yonghong; Shang, Hongcai; Xing, Yanwei

    2017-01-01

    In this study, we assessed the effect of rehabilitation exercise after percutaneous coronary intervention (PCI) in patients with coronary heart disease (CHD). We performed a meta-analysis to determine the effects of exercise in patients after PCI. The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, the Embase database, China National Knowledge Internet (CNKI), China Biology Medicine (CBM), and the Wanfang Database were searched for randomized controlled trials (RCTs). The key words used for the searches were PCI, exercise, walking, jogging, Tai Chi, and yoga. Six studies with 682 patients met our inclusion criteria; we chose the primary endpoint events of cardiac death, recurrence of myocardial infarction (MI), repeated PCI, coronary artery bypass grafting (CABG), and restenosis, and the secondary endpoint measures included recurrent angina, treadmill exercise (total exercise time, ST-segment decline, angina, and maximum exercise tolerance). The results showed that exercise was not clearly associated with reductions in cardiac death, recurrence of MI, repeated PCI, CABG, or restenosis. However, the exercise group exhibited greater improvements in recurrent angina, total exercise time, ST-segment decline, angina, and maximum exercise tolerance than did the control group. Future studies need to expand the sample size and improve the quality of reporting of RCTs. PMID:28303967

  17. Effects of exercise-based cardiac rehabilitation in patients after percutaneous coronary intervention: A meta-analysis of randomized controlled trials.

    PubMed

    Yang, Xinyu; Li, Yanda; Ren, Xiaomeng; Xiong, Xingjiang; Wu, Lijun; Li, Jie; Wang, Jie; Gao, Yonghong; Shang, Hongcai; Xing, Yanwei

    2017-03-17

    In this study, we assessed the effect of rehabilitation exercise after percutaneous coronary intervention (PCI) in patients with coronary heart disease (CHD). We performed a meta-analysis to determine the effects of exercise in patients after PCI. The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, the Embase database, China National Knowledge Internet (CNKI), China Biology Medicine (CBM), and the Wanfang Database were searched for randomized controlled trials (RCTs). The key words used for the searches were PCI, exercise, walking, jogging, Tai Chi, and yoga. Six studies with 682 patients met our inclusion criteria; we chose the primary endpoint events of cardiac death, recurrence of myocardial infarction (MI), repeated PCI, coronary artery bypass grafting (CABG), and restenosis, and the secondary endpoint measures included recurrent angina, treadmill exercise (total exercise time, ST-segment decline, angina, and maximum exercise tolerance). The results showed that exercise was not clearly associated with reductions in cardiac death, recurrence of MI, repeated PCI, CABG, or restenosis. However, the exercise group exhibited greater improvements in recurrent angina, total exercise time, ST-segment decline, angina, and maximum exercise tolerance than did the control group. Future studies need to expand the sample size and improve the quality of reporting of RCTs.

  18. Design And Analysis Of Linear Control Systems

    NASA Technical Reports Server (NTRS)

    Jamison, John W.

    1991-01-01

    Package of five computer programs developed to assist in design and analysis of linear control systems by use of root-locus and frequency-response methods. Package written in FORTRAN (BODE, TPEAK) and BASIC (LOCUS, KTUNE, and POLYROOT).

  19. Design And Analysis Of Linear Control Systems

    NASA Technical Reports Server (NTRS)

    Jamison, John W.

    1991-01-01

    Package of five computer programs developed to assist in design and analysis of linear control systems by use of root-locus and frequency-response methods. Package written in FORTRAN (BODE, TPEAK) and BASIC (LOCUS, KTUNE, and POLYROOT).

  20. FPGA based control system for space instrumentation

    NASA Astrophysics Data System (ADS)

    Di Giorgio, Anna M.; Cerulli Irelli, Pasquale; Nuzzolo, Francesco; Orfei, Renato; Spinoglio, Luigi; Liu, Giovanni S.; Saraceno, Paolo

    2008-07-01

    The prototype for a general purpose FPGA based control system for space instrumentation is presented, with particular attention to the instrument control application software. The system HW is based on the LEON3FT processor, which gives the flexibility to configure the chip with only the necessary HW functionalities, from simple logic up to small dedicated processors. The instrument control SW is developed in ANSI C and for time critical (<10μs) commanding sequences implements an internal instructions sequencer, triggered via an interrupt service routine based on a HW high priority interrupt.

  1. Towards a Mobile-Based Platform for Traceability Control and Hazard Analysis in the Context of Parenteral Nutrition: Description of a Framework and a Prototype App

    PubMed Central

    2016-01-01

    Background The parenteral nutrient (PN) mixtures may pose great risks of physical, microbiological, and chemical contamination during their preparation, storage, distribution, and administration. These potential hazards must be controlled under high levels of excellence to prevent any serious complications for the patients. As a result, management control and traceability of any of these medications is of utmost relevance for the patient care, along with ensuring treatment continuity and adherence. Objective The aim of this study is to develop a mobile-based platform to support the control procedures and traceability services in the domain of parenteral nutrient (PN) mixtures in an efficient and nonintrusive manner. Methods A comprehensive approach combining techniques of software engineering and knowledge engineering was used for the characterization of the framework. Local try-outs for evaluation were performed in a number of application areas, carrying out a test/retest monitoring to detect possible errors or conflicts in different contexts and control processes throughout the entire cycle of PN. From these data, the absolute and relative frequencies (percentages) were calculated. Results A mobile application for the Android operating system was developed. This application allows reading different types of tags and interacts with the local server according to a proposed model. Also, through an internal caching mechanism, the availability of the system is preserved even in the event of problems with the network connection. A set of 1040 test traces were generated for the assessment of the system under various environments tested. Among those, 102 traces (9.81%) involved conflictive situations that were properly taken care of in this paper by suggesting solutions to overcome them. Conclusions A mobile oriented system was generated and tested in order to allow enhanced control and quality management of PN mixtures that is easy to integrate into the daily praxis of

  2. Substructure-based control of flexible structures

    NASA Astrophysics Data System (ADS)

    Babuska, Vit

    The desire to build large space structures has motivated research into the problem of flexible structure control. In general, the controllers for these structures can be designed using a centralized strategy or a decentralized strategy. In the centralized approach, the controller is based on a model of the complete structure. In the decentralized approach, the structure model is decomposed into subsystems for which controllers are designed, and then these subsystem controllers are combined to control the complete structure. The subsystems can be mathematical constructs such as groups of modes, or physical subsystems like substructures. This dissertation examines substructure-based decentralized design of controllers for flexible structures. Three different, but related, topics are discussed in this work. First, a relationship is shown to exist between the substructural controller synthesis (SCS) method of designing active controllers for flexible structures and decentralized control using overlapping information sets. It is shown that, in the case of full-state feedback, the SCS method is a specific case of decentralized control using overlapping subsystems. In the case of dynamic output feedback (e.g., LQG controllers), the SCS method departs from standard decentralized control techniques. The controllers are 'assembled' by extending the concept of substructural assembly to general linear systems. Next, a new design method is proposed which combines the concept of component mode synthesis (CMS) with control theory in a decentralized method for the design of controllers for flexible structures. This method, called the augmented physical component synthesis (APCS) method, creates augmented substructural components. These components are substructures whose boundaries are loaded with some dynamics of the adjacent substructures. This allows global control objectives such as line-of-sight error minimization to be met with a substructure-based design strategy. Finally

  3. Solar Dynamic Power System Stability Analysis and Control

    NASA Technical Reports Server (NTRS)

    Momoh, James A.; Wang, Yanchun

    1996-01-01

    The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

  4. Using bioluminescent biosensors for hazard analysis and critical control point (HACCP) in wastewater control.

    PubMed

    Valat, C; Champiat, D; Degorce-Dumas, J R; Thomas, O

    2004-01-01

    Starting from a new approach for water pollution control and wastewater treatment plant management, the hazard analysis and critical control point (HACCP) quality concept, the interest for the development of new rapid and sensitive methods such as bioluminescence-based methods is evident. After an introduction of the HACCP procedure, a bibliographic study of the bioluminescence potentiality is presented and discussed.

  5. Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis.

    PubMed

    Martin, Vincent; Zhou, Xiaoyan; Marshall, Edith; Jia, Beibei; Fusheng, Guo; FrancoDixon, Mary Ann; DeHaan, Nicoline; Pfeiffer, Dirk U; Soares Magalhães, Ricardo J; Gilbert, Marius

    2011-12-01

    Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions.

  6. Failure Mode Effects Analysis for an Accelerator Control System

    SciTech Connect

    Hartman, Steven M

    2009-01-01

    Failure mode effects analysis (FMEA) has been used in industry for design, manufacturing and assembly process quality control. It describes a formal approach for categorizing how a process may fail and for prioritizing failures based on their severity, frequency and likelihood of detection. Experience conducting a partial FMEA of an accelerator subsystem and its related control system will be reviewed. The applicability of the FMEA process to an operational accelerator control system will be discussed.

  7. Trend Analysis of Controlled Thin Metallization Flashover

    DTIC Science & Technology

    2005-06-01

    TREND ANALYSIS OF CONTROLLED THIN METALLIZATION FLASHOVER S.O. Olabisi, K. M. Burke, W. J. Sarjeant Energy Systems Institute, University at...Abstract Tests validating the consistency and repeatability of controlled electrical surface flashover on metallized thin film insulators...were performed. The study of electrical surface flashover has been mainly confined to its prevention under various contaminated conditions such as

  8. Analysis Of Control Of Cooperating Robot Arms

    NASA Technical Reports Server (NTRS)

    Kreutz, Kenneth K.; Wen, John Ting-Yung

    1991-01-01

    Paper presents theoretical analysis of general problem of how to control motions of, and forces exerted by, several multiple-rigid-link robot arms that cooperatively manipulate common rigid object. Emphasis mainly on construction, via full-dynamics approach, of control laws relatively independent of dynamical models.

  9. Type 1 diabetes risk analysis on dried blood spot samples from population-based newborns: design and feasibility of an unselected case-control study.

    PubMed

    Eising, Stefanie; Svensson, Jannet; Skogstrand, Kristin; Nilsson, Anita; Lynch, Kristian; Andersen, Paal Skytt; Lernmark, Ake; Hougaard, David M; Pociot, Flemming; Nørgaard-Pedersen, Bent; Nerup, Jørn

    2007-11-01

    Development of type 1 diabetes mellitus (T1D) may be triggered pre- or perinatally by multiple factors. Identifying new predisposing T1D markers or combinations of markers in a large, well-characterised case-control collection may be important for future T1D prevention. The present work describes the design and feasibility of a large and unselected case-control study, which will define and evaluate prediction criteria for T1D at the time of birth. Danish registries (Biological Specimen Bank for Neonatal Screening, and the National Discharge Registry) made it possible to identify and collect dried blood spots (DBS) from newborns who later developed T1D (cases) born 1981-2002. DBS samples from 2086 cases and two matching control subjects per case were analysed for genetic and immune factors that are associated with T1D: (a) candidate genes (HLA, INS and CTLA4), (b) cytokines and inflammatory markers, (c) islet auto-antibodies (GAD65A, IA-2A). The objective of the study was to define reliable prediction tools for T1D using samples available at the time of birth. In a unique approach, the study linked a large unselected and population-based sample resource to well-ascertained clinical databases and advanced technology. It combined genetic, immunological and demographic data to develop prediction algorithms. It also provided a resource for future studies in which new genetic markers can be included as they are identified.

  10. Relationship between tea consumption and pancreatic cancer risk: a meta-analysis based on prospective cohort studies and case-control studies.

    PubMed

    Chen, Ke; Zhang, Qi; Peng, Min; Shen, Yanping; Wan, Peng; Xie, Guoming

    2014-09-01

    The aim of this study was to evaluate the relationship between regular tea consumption and the risk of pancreatic cancer by a meta-analysis. Two investigators independently performed a computer retrieve on the electronic databases of Embase, PubMed, and Ovidsp for prospective cohort studies and case-control studies on regular tea consumption and the risk of pancreatic cancer incidence. The keywords using for search were ('Pancreas' OR 'pancreatic') AND ('neoplasms' OR 'carcinoma' OR 'cancer') AND 'tea'. Risk ratios (RRs) and 95% confidence interval (CI) were used to determine the effect of tea consumption on pancreatic cancer. A total of 14 studies were included (8078 pancreatic cancer patients, with a total of 859 783 patients) in the present meta-analysis. The pooled results of effect size indicated that tea consumption has no significant relationship with risk of pancreatic cancer (RR=0.99, 95% CI: 0.89-1.11, P=0.922). However, the subgroup analysis of different countries showed a statistical decrease in pancreatic cancer risk by high consumption of tea in a Chinese population (RR=0.76, 95% CI: 0.59-0.98, P=0.036). Similar results were found in the elderly (>60 years old) (RR=0.76, 95% CI: 0.60-0.96, P=0.023). In conclusion, the present meta-analysis of 14 studies suggests that the correlation between tea consumption and the risk of pancreatic cancer in the general population is not significant, but an increase in tea consumption can reduce the risk of pancreatic cancer disease in Chinese populations and in individuals older than 60 years of age. It is necessary to formulate more rigorous designs of regional studies to further confirm the relationship between tea consumption and pancreatic cancer.

  11. Firmware Modification Analysis in Programmable Logic Controllers

    DTIC Science & Technology

    2014-03-27

    MODIFICATION ANALYSIS IN PROGRAMMABLE LOGIC CONTROLLERS Arturo M. Garcia Jr., B.S.S.E.C.A. Captain, USA Approved: //signed// Robert F. Mills , PhD...Matthew 5:37 v Acknowledgments My sincere gratitude to my committee for their guidance and teamwork which made this thesis possible. Dr. Mills ...2012. 2012. [5] Bolton, William. Programmable logic controllers. Newnes, 2009. [6] Boyer, Stuart . SCADA: Supervisory Control and Data Aquisition 4th

  12. Improving Anesthesiologists' Ability to Speak Up in the Operating Room: A Randomized Controlled Experiment of a Simulation-Based Intervention and a Qualitative Analysis of Hurdles and Enablers.

    PubMed

    Raemer, Daniel B; Kolbe, Michaela; Minehart, Rebecca D; Rudolph, Jenny W; Pian-Smith, May C M

    2016-04-01

    The authors addressed three questions: (1) Would a realistic simulation-based educational intervention improve speaking-up behaviors of practicing nontrainee anesthesiologists? (2) What would those speaking-up behaviors be when the issue emanated from a surgeon, a circulating nurse, or an anesthesiologist colleague? (3) What were the hurdles and enablers to speaking up in those situations? The authors conducted a simulation-based randomized controlled experiment from March 2008-February 2011 at the Center for Medical Simulation, Boston, Massachusetts. During a mandatory crisis management course for practicing nontrainee anesthesiologists from five Boston institutions, a 50-minute workshop on speaking up was conducted for intervention (n = 35) and control (n = 36) groups before or after, respectively, an experimental scenario with three events. The authors analyzed videos of the experimental scenarios and debriefing sessions. No statistically significant differences between the intervention and control group subjects with respect to speaking-up actions were observed in any of the three events. The five most frequently mentioned hurdles to speaking up were uncertainty about the issue, stereotypes of others on the team, familiarity with the individual, respect for experience, and the repercussion expected. The five most frequently mentioned enablers were realizing the speaking-up problem, having a speaking-up rubric, certainty about the consequences of speaking up, familiarity with the individual, and having a second opinion or getting help. An educational intervention alone was ineffective in improving the speaking-up behaviors of practicing nontrainee anesthesiologists. Other measures to change speaking-up behaviors could be implemented and might improve patient safety.

  13. Reduced amygdala volume is associated with deficits in inhibitory control: a voxel- and surface-based morphometric analysis of comorbid PTSD/mild TBI.

    PubMed

    Depue, B E; Olson-Madden, J H; Smolker, H R; Rajamani, M; Brenner, L A; Banich, M T

    2014-01-01

    A significant portion of previously deployed combat Veterans from Operation Enduring Freedom and Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) are affected by comorbid posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI). Despite this fact, neuroimaging studies investigating the neural correlates of cognitive dysfunction within this population are almost nonexistent, with the exception of research examining the neural correlates of diagnostic PTSD or TBI. The current study used both voxel-based and surface-based morphometry to determine whether comorbid PTSD/mTBI is characterized by altered brain structure in the same regions as observed in singular diagnostic PTSD or TBI. Furthermore, we assessed whether alterations in brain structures in these regions were associated with behavioral measures related to inhibitory control, as assessed by the Go/No-go task, self-reports of impulsivity, and/or PTSD or mTBI symptoms. Results indicate volumetric reductions in the bilateral anterior amygdala in our comorbid PTSD/mTBI sample as compared to a control sample of OEF/OIF Veterans with no history of mTBI and/or PTSD. Moreover, increased volume reduction in the amygdala predicted poorer inhibitory control as measured by performance on the Go/No-go task, increased self-reported impulsivity, and greater symptoms associated with PTSD. These findings suggest that alterations in brain anatomy in OEF/OIF/OND Veterans with comorbid PTSD/mTBI are associated with both cognitive deficits and trauma symptoms related to PTSD.

  14. Reduced Amygdala Volume Is Associated with Deficits in Inhibitory Control: A Voxel- and Surface-Based Morphometric Analysis of Comorbid PTSD/Mild TBI

    PubMed Central

    Depue, B. E.; Olson-Madden, J. H.; Smolker, H. R.; Rajamani, M.; Brenner, L. A.; Banich, M. T.

    2014-01-01

    A significant portion of previously deployed combat Veterans from Operation Enduring Freedom and Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) are affected by comorbid posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI). Despite this fact, neuroimaging studies investigating the neural correlates of cognitive dysfunction within this population are almost nonexistent, with the exception of research examining the neural correlates of diagnostic PTSD or TBI. The current study used both voxel-based and surface-based morphometry to determine whether comorbid PTSD/mTBI is characterized by altered brain structure in the same regions as observed in singular diagnostic PTSD or TBI. Furthermore, we assessed whether alterations in brain structures in these regions were associated with behavioral measures related to inhibitory control, as assessed by the Go/No-go task, self-reports of impulsivity, and/or PTSD or mTBI symptoms. Results indicate volumetric reductions in the bilateral anterior amygdala in our comorbid PTSD/mTBI sample as compared to a control sample of OEF/OIF Veterans with no history of mTBI and/or PTSD. Moreover, increased volume reduction in the amygdala predicted poorer inhibitory control as measured by performance on the Go/No-go task, increased self-reported impulsivity, and greater symptoms associated with PTSD. These findings suggest that alterations in brain anatomy in OEF/OIF/OND Veterans with comorbid PTSD/mTBI are associated with both cognitive deficits and trauma symptoms related to PTSD. PMID:24724093

  15. Stress analysis of magnetically controlled reactor

    NASA Astrophysics Data System (ADS)

    Tong, Ben; Qingxin, Yang; Rongge, Yan; Lihua, Zhu; Ling, Weng; Ying, Sun

    2017-05-01

    To provide technique references for vibration reduction of magnetically controlled reactors (MCRs), stress, which is the inherent reason of vibration and noise, should be investigated. Stresses in reactor cores are produced due to the magnetostriction deformation of silicon steel and electromagnetic force between the core discs. So far, stress analysis on reactor cores was based on one-way coupled numerical method, which did not consider the influence of the stress on magnetic properties of the core material. Thus, multi-group magnetization and magnetostriction characteristics curves of silicon steel under different tensile stresses are measured firstly to support the computation. From the experiment results, it can be seen that magnetic properties of silicon steel change with stress. Then an electromagneto-mechanical two-way coupled numerical model for MCRs considering magnetostrictive effect and electromagnetic force effect is proposed. Stress distribution of MCR cores under the combination excitation of the sinusoidal wave current and different direct currents are calculated. From the computed results, it can be seen that a larger direct current has greater influence on MCRs vibration, which provides a theory basis for further analysis of vibration and noise reduction.

  16. Analysis of industry-generated data. Part 2: Risk-based sampling plan for efficient self-control of aflatoxin M₁ contamination in raw milk.

    PubMed

    Farkas, Zsuzsa; Trevisani, Marcello; Horváth, Zsuzsanna; Serraino, Andrea; Szabó, István J; Kerekes, Kata; Szeitzné-Szabó, Mária; Ambrus, Arpád

    2014-01-01

    Aflatoxin M₁ (AFM1) contamination in 21,969 milk samples taken in Italy during 2005-08 and 2010 provided the basis for designing an early warning self-control plan. Additionally, 4148 AFM1 data points from the mycotoxin crisis (2003-04) represented the worst case. No parametric function provided a good fit for the skewed and scattered AFM1 concentrations. The acceptable reference values, reflecting the combined uncertainty of AFM1 measured in consignments consisting of milk from one to six farms, ranged from 40 to 16.7 ng kg(-1), respectively. Asymmetric control charts with these reference values, 40 and 50 ng kg(-1) warning and action limits are recommended to assess immediately the distribution of AFM1 concentration in incoming consignments. The moving window method, presented as a worked example including 5 days with five samples/day, enabled verification of compliance of production with the legal limit in 98% of the consignments at a 94% probability level. The sampling plan developed assumes consecutive analyses of samples taken from individual farms, which makes early detection of contamination possible and also immediate corrective actions if the AFM1 concentration in a consignment exceeds the reference value. In the latter case different control plans with increased sampling frequency should be applied depending on the level and frequency of contamination. As aflatoxin B₁ increases in feed at about the same time, therefore a coordinated sampling programme performed by the milk processing plants operating in a confined geographic area is more effective and economical then the individual ones. The applicability of the sample size calculation based on binomial theorem and the fast response rate resulting from the recommended sampling plan were verified by taking 1000-10,000 random samples with replacement from the experimental databases representing the normal, moderately and highly contaminated periods. The efficiency of the control plan could be

  17. Effects of mindfulness-based cognitive therapy on mental disorders: a systematic review and meta-analysis of randomised controlled trials

    PubMed Central

    Galante, Julieta; Iribarren, Sarah J.; Pearce, Patricia F.

    2016-01-01

    Objective Mindfulness-based cognitive therapy (MBCT) is a programme developed to prevent depression relapse, but has been applied for other disorders. Our objective was to systematically review and meta-analyse the evidence on the effectiveness and safety of MBCT for the treatment of mental disorders. Methods Searches were completed in CENTRAL, MEDLINE, EMBASE, LILACS, PsychINFO, and PsycEXTRA in March 2011 using a search strategy with the terms ‘mindfulness-based cognitive therapy’, ‘mindfulness’, and ‘randomised controlled trials’ without time restrictions. Selection criteria of having a randomised controlled trial design, including patients diagnosed with mental disorders, using MBCT according to the authors who developed MBCT and providing outcomes that included changes in mental health were used to assess 608 reports. Two reviewers applied the pre-determined selection criteria and extracted the data into structured tables. Meta-analyses and sensitivity analyses were completed. Results Eleven studies were included. Most of them evaluated depression and compared additive MBCT against usual treatment. After 1 year of follow-up MBCT reduced the rate of relapse in patients with three or more previous episodes of depression by 40% (5 studies, relative risk [95% confidence interval]: 0.61 [0.48, 0.79]). Other meta-analysed outcomes were depression and anxiety, both with significant results but unstable in sensitivity analyses. Methodological quality of the reports was moderate. Conclusion Based on this review and meta-analyses, MBCT is an effective intervention for patients with three or more previous episodes of major depression. PMID:27660642

  18. Compensation-based control for lossy communication networks

    NASA Astrophysics Data System (ADS)

    Gommans, T. M. P.; Heemels, W. P. M. H.; Bauer, N. W.; van de Wouw, N.

    2013-10-01

    In this paper, we are concerned with the stability analysis and the design of stabilising compensation-based control algorithms for networked control systems (NCSs) that exhibit packet dropouts. In order to increase the robustness against packet dropouts for such NCSs, we propose a new type of model-based dropout compensator, which depends on the local dropout history. Moreover, we provide linear matrix inequality based synthesis conditions for such compensators guaranteeing robust stability. The analysis and design framework includes both worst-case-bound and stochastic models to describe the packet-dropout behaviour in both the sensor-to-controller and the controller-to-actuator channels. Numerical examples demonstrate the significantly improved robustness with respect to packet dropouts using the proposed dropout compensator, compared to using the existing zero strategy and the hold strategy.

  19. Analysis and decoupling control of a permanent magnet spherical actuator

    NASA Astrophysics Data System (ADS)

    Zhang, Liang; Chen, Weihai; Liu, Jingmeng; Wu, Xingming

    2013-12-01

    This paper presents the analysis and decoupling control of a spherical actuator, which is capable of performing three degree-of-freedom motion in one joint. The proposed actuator consists of a rotor with multiple PM (Permanent Magnet) poles in a circle and a stator with circumferential coils in three layers. Based on this actuator design, a decoupling control approach is developed. Unlike existing control methods that each coil is responsible for both the spinning and tilting motion, the proposed control strategy specifies the function of each coil. Specifically, the spinning motion is governed by the middle layer coils with a step control approach; while the tilting motion is regulated by upper and lower coils with a computed torque control method. Experiments have been conducted on the prototype to verify the validity of the design procedure, and the experimental results demonstrate the effectiveness of the analysis and control strategy.

  20. Resume and analysis of NACA lateral control research

    NASA Technical Reports Server (NTRS)

    Weick, F. E.; Jones, R. T.

    1976-01-01

    An analysis of the principal results of recent lateral control research is made. Two things are considered of primary importance in judging the effectiveness of different control devices: The (calculated) banking and yawing motion of a typical small airplane caused by a deflection of the control, and the stick force required to produce this deflection. The report includes a table in which a number of different lateral control devices are compared on these bases. Test flights demonstrated that satisfactory lateral control at high angles of attack depends as much on the retention of stability as on aileron effectiveness.

  1. Minimum 4-year outcomes of cervical total disc arthroplasty versus fusion: a meta-analysis based on prospective randomized controlled trials.

    PubMed

    Wu, Ai-Min; Xu, Hui; Mullinix, Kenneth Paul; Jin, Hai-Ming; Huang, Zhe-Yu; Lv, Qing-Bo; Wang, Sheng; Xu, Hua-Zi; Chi, Yong-Long

    2015-04-01

    The prevalence of cervical disc disease is high, and the traditional surgical method of anterior cervical discectomy and fusion (ACDF) carries with it the disadvantages of motion loss at the operated level, and accelerated adjacent level disc degeneration. Preliminary results of the efficacy and reoperative rate comparing TDA versus ACDF have been reported; however, the long-term outcomes of TDA versus ACDF still remain a topic of debate. This review was prepared following the standard procedures set forth by the Cochrane Collaboration organization, and preferred reporting items for systematic reviews and meta-analyses (PRISMA). The only studies included were randomized controlled trials with a minimum of 4 years of follow-up data. The meta-analysis included the neck disability index (NDI), visual analog scale (VAS) of neck and arm pain, SF-36 physical component scores (SF-36 PCS), over success, neurological success, work status, implant-related complications, and secondary surgery events. Four randomized controlled trials meet the inclusion criteria. The long-term improvement of NDI, VAS of neck and arm pain, SF-36 PCS, over success, and neurological success favored the TDA group. The TDA group also had a lower incidence of secondary surgery for both the index level (RR: 0.45 [0.28, 0.72]) and adjacent level (RR: 0.53 [0.33, 0.88]). In this meta-analysis of 4 included RCTs with a minimum 4 years of follow-ups, total disc arthroplasty showed improvements over ACDF as measured by the NDI, VAS of neck and arm pain, and SF-36 PCS.

  2. Adaptive control of space based robot manipulators

    NASA Technical Reports Server (NTRS)

    Walker, Michael W.; Wee, Liang-Boon

    1991-01-01

    For space based robots in which the base is free to move, motion planning and control is complicated by uncertainties in the inertial properties of the manipulator and its load. A new adaptive control method is presented for space based robots which achieves globally stable trajectory tracking in the presence of uncertainties in the inertial parameters of the system. A partition is made of the fifteen degree of freedom system dynamics into two parts: a nine degree of freedom invertible portion and a six degree of freedom noninvertible portion. The controller is then designed to achieve trajectory tracking of the invertible portion of the system. This portion consist of the manipulator joint positions and the orientation of the base. The motion of the noninvertible portion is bounded, but unpredictable. This portion consist of the position of the robot's base and the position of the reaction wheel.

  3. Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

    NASA Astrophysics Data System (ADS)

    Keum, Jung-Hoon; Ra, Sung-Woong

    2009-12-01

    Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

  4. Efficacy and safety of pramipexole extended-release in Parkinson's disease: a review based on meta-analysis of randomized controlled trials.

    PubMed

    Shen, T; Ye, R; Zhang, B

    2017-06-01

    We performed a meta-analysis of randomized controlled trials to evaluate the efficacy and safety of pramipexole extended-release (pramipexole ER) versus pramipexole immediate-release (pramipexole IR) or placebo in Parkinson's disease. We performed a systematic online search for clinical trials for pramipexole ER treatment up to 1 August 2016. We assessed differences in Unified Parkinson's Disease Rating Scale (UPDRS) scores, percentage of 'on' time or 'off' time, withdrawals, adverse events (AEs) and life quality between pramipexole ER and pramipexole IR or placebo. Data analyses were performed by the Cochrane Collaboration's Review Manager 5.3 software. Six randomized controlled trials were included. Compared with placebo, pramipexole ER achieved a significant improvement in the UPDRS Part II + III score [weighted mean difference, -4.81; 95% confidence interval (CI), -6.40 to -3.23], whereas no significant difference was found in the UPDRS Part III + III score between pramipexole ER and pramipexole IR groups (weighted mean difference, -0.26; 95% CI, -1.15 to 0.64). No differences were found in total AEs (relative risk, 0.97; 95% CI, 0.92 to 1.03), drug-related AEs (relative risk, 0.97; 95% CI, 0.92 to 1.03) or the commonly reported AEs between pramipexole ER and pramipexole IR. Pramipexole ER is as safe and effective as pramipexole IR in the treatment of Parkinson's disease. © 2017 EAN.

  5. Synthesis, characterization and in vitro cytotoxicity analysis of a novel cellulose based drug carrier for the controlled delivery of 5-fluorouracil, an anticancer drug

    NASA Astrophysics Data System (ADS)

    Anirudhan, Thayyath S.; Nima, Jayachandran; Divya, Peethambaran L.

    2015-11-01

    The present investigation concerns the development and evaluation of a novel drug delivery system, aminated-glycidylmethacrylate grafted cellulose-grafted polymethacrylic acid-succinyl cyclodextrin (Cell-g-(GMA/en)-PMA-SCD) for the controlled release of 5-Fluorouracil, an anticancer drug. The prepared drug carrier was characterized by FT-IR, XRD and SEM techniques. Binding kinetics and isotherm studies of 5-FU onto Cell-g-(GMA/en)-PMA-SCD were found to follow pseudo-second-order and Langmuir model respectively. Maximum binding capacity of drug carrier was found to be 149.09 mg g-1 at 37 °C. Swelling studies, in vitro release kinetics, drug loading efficiency and encapsulation efficiency of Cell-g-(GMA/en)-PMA-SCD were studied. The release kinetics was analyzed using Ritger-Peppas equation at pH 7.4. Cytotoxicity analysis on MCF-7 (human breast carcinoma) cells indicated that the drug carrier shows sustained and controlled release of drug to the target site. Hence, it is evident from this investigation that Cell-g-(GMA/en)-PMA-SCD could be a promising carrier for 5-FU.

  6. Exercise-based interventions and C-reactive protein in overweight and obese youths: a meta-analysis of randomized controlled trials.

    PubMed

    García-Hermoso, Antonio; Sánchez-López, Mairena; Escalante, Yolanda; Saavedra, Jose M; Martínez-Vizcaíno, Vicente

    2016-04-01

    One of the most commonly measured markers of inflammation in clinical settings is C-reactive protein (CRP). The purpose of this meta-analysis was to examine the evidence for the effectiveness of physical exercise interventions on modifying the levels of serum CRP in children and adolescents with excess of weight. Two independent reviewers assessed articles from seven databases. Studies were limited to physical exercise interventions in children and adolescents diagnosed as overweight or obese, and including a comparison control group. Weighted mean difference (WMD) was calculated using random-effects model and potential moderators were explored (i.e., weight status, ages, duration of study, frequency of exercise per week, and duration of session). The heterogeneity of the studies was estimated using Cochran's Q-statistic and I(2). Nine randomized controlled trials met the inclusion criteria (n = 427 youths). Overall, results suggest a nonsignificant trend toward a reduction CRP levels (WMD = -0.72 mg/l; 95% confidence interval: -1.52 to 0.08; P = 0.077). Also, there were not significant moderators of exercise effects on CRP. These results suggest that exercise programs in children and adolescents not mitigate the inflammatory effects of excess weight, although there was a trend toward reduction.

  7. Association between MTHFR C677T Polymorphism and Risk of Acute Lymphoblastic Leukemia: A Meta-Analysis Based on 51 Case-Control Studies

    PubMed Central

    Li, Su-yi; Ye, Jie-yu; Liang, En-yu; Zhou, Li-xia; Yang, Mo

    2015-01-01

    Background Studies and systematic reviews have reached inconsistent conclusions on the role of 5, 10-methylenetetrahydrofolate reductase (MTHFR) polymorphism C677T in acute lymphoblastic leukemia (ALL) risk. Material/Methods The present meta-analysis comprising of 51 case-control studies, including 7892 cases and 14 280 controls was performed to reevaluate the association between MTHFR C677T polymorphism and ALL risk. Results Statistical differences were found in the dominant model (TT+CT vs. CC, odd ratio (OR)=0.89, 95% CI, 0.79–1.00, P=0.04) and the CT vs. CC (OR=0.89, 95% CI, 0.80–1.00, P=0.05), but not in the allele contrast model (T vs. C, OR=0.92, 95% CI, 0.84–1.01, P=0.08), additive model (TT vs. CC, OR=0.87, 95% CI, 0.73–1.05, P=0.15), or recessive model (TT vs. CT+CC, OR=0.94, 95% CI, 0.81–1.10, P=0.44) in overall populations. In the subgroup analyses stratified by age (children and adults) and ethnicity (Asian and Caucasian), no significant associations between MTHFR C677T polymorphism and ALL risk were observed. Conclusions The current study found no sufficient evidence of a protective role of MTHFR C677T polymorphism in ALL susceptibility. PMID:25761797

  8. LANL material control indicator analysis program

    SciTech Connect

    Roybal, G. S.

    2001-01-01

    The possibility of SNM diversion/theft is a major concern to organizations charged with control of Special Nuclear Material (SNM). Several methods have been put in place to deter and or detect losses of SNM. These include inventory, material control physical barriers and the use of material control indicators (MCI). This paper will discuss the multi-tier LANL review mechanism for detecting and isolating missing SNM by the use of Material Control Indicators. Los Alamos MCI include daily analysis and review of item adjustments, weekly review of item adjustments, monthly analysis and review of inventory differences by Process Status and by Material Balance Areas, and quarterly analysis and review of Propagation of Variance. This paper, by providing an introduction to a site-specific application of MCI's, assists safeguards professionals in understanding the importance of an MCI Program in detecting accumulation for subsequent diversion/theft of special nuclear material.

  9. The Complexity of Standing Postural Control in Older Adults: A Modified Detrended Fluctuation Analysis Based upon the Empirical Mode Decomposition Algorithm

    PubMed Central

    Liu, Dongdong; Hu, Kun; Zhang, Jue; Fang, Jing

    2013-01-01

    Human aging into senescence diminishes the capacity of the postural control system to adapt to the stressors of everyday life. Diminished adaptive capacity may be reflected by a loss of the fractal-like, multiscale complexity within the dynamics of standing postural sway (i.e., center-of-pressure, COP). We therefore studied the relationship between COP complexity and adaptive capacity in 22 older and 22 younger healthy adults. COP magnitude dynamics were assessed from raw data during quiet standing with eyes open and closed, and complexity was quantified with a new technique termed empirical mode decomposition embedded detrended fluctuation analysis (EMD-DFA). Adaptive capacity of the postural control system was assessed with the sharpened Romberg test. As compared to traditional DFA, EMD-DFA more accurately identified trends in COP data with intrinsic scales and produced short and long-term scaling exponents (i.e., αShort, αLong) with greater reliability. The fractal-like properties of COP fluctuations were time-scale dependent and highly complex (i.e., αShort values were close to one) over relatively short time scales. As compared to younger adults, older adults demonstrated lower short-term COP complexity (i.e., greater αShort values) in both visual conditions (p>0.001). Closing the eyes decreased short-term COP complexity, yet this decrease was greater in older compared to younger adults (p<0.001). In older adults, those with higher short-term COP complexity exhibited better adaptive capacity as quantified by Romberg test performance (r2 = 0.38, p<0.001). These results indicate that an age-related loss of COP complexity of magnitude series may reflect a clinically important reduction in postural control system functionality as a new biomarker. PMID:23650518

  10. A case-control association study and family-based expression analysis of the bipolar disorder candidate gene PI4K2B.

    PubMed

    Houlihan, Lorna M; Christoforou, Andrea; Arbuckle, Margaret I; Torrance, Helen S; Anderson, Susan M; Muir, Walter J; Porteous, David J; Blackwood, Douglas H; Evans, Kathryn L

    2009-12-01

    Bipolar disorder, schizophrenia and recurrent major depression are complex psychiatric illnesses with a substantial, yet unknown genetic component. Linkage of bipolar disorder and recurrent major depression with markers on chromosome 4p15-p16 has been identified in a large Scottish family and three smaller families. Analysis of haplotypes in the four chromosome 4p-linked families, identified two regions, each shared by three of the four families, which are also supported by a case-control association study. The candidate gene phosphatidylinositol 4-kinase type-II beta (PI4K2B) lies within one of these regions. PI4K2B is a strong functional candidate as it is a member of the phosphatidylinositol pathway, which is targeted by lithium for therapeutic effect in bipolar disorder. Two approaches were undertaken to test the PI4K2B candidate gene as a susceptibility factor for psychiatric illness. First, a case-control association study, using tagging SNPs from the PI4K2B genomic region, in bipolar disorder (n=368), schizophrenia (n=386) and controls (n=458) showed association with a two-marker haplotype in schizophrenia but not bipolar disorder (rs10939038 and rs17408391, global P=0.005, permuted global P=0.039). Second, expression studies at the allele-specific mRNA and protein level using lymphoblastoid cell lines from members of the large Scottish family, which showed linkage to 4p15-p16 in bipolar disorder and recurrent major depression, showed no difference in expression differences between affected and non-affected family members. There is no evidence to suggest that PI4K2B is contributing to bipolar disorder in this family but a role for this gene in schizophrenia has not been excluded.

  11. Gesture Based Control and EMG Decomposition

    NASA Technical Reports Server (NTRS)

    Wheeler, Kevin R.; Chang, Mindy H.; Knuth, Kevin H.

    2005-01-01

    This paper presents two probabilistic developments for use with Electromyograms (EMG). First described is a new-electric interface for virtual device control based on gesture recognition. The second development is a Bayesian method for decomposing EMG into individual motor unit action potentials. This more complex technique will then allow for higher resolution in separating muscle groups for gesture recognition. All examples presented rely upon sampling EMG data from a subject's forearm. The gesture based recognition uses pattern recognition software that has been trained to identify gestures from among a given set of gestures. The pattern recognition software consists of hidden Markov models which are used to recognize the gestures as they are being performed in real-time from moving averages of EMG. Two experiments were conducted to examine the feasibility of this interface technology. The first replicated a virtual joystick interface, and the second replicated a keyboard. Moving averages of EMG do not provide easy distinction between fine muscle groups. To better distinguish between different fine motor skill muscle groups we present a Bayesian algorithm to separate surface EMG into representative motor unit action potentials. The algorithm is based upon differential Variable Component Analysis (dVCA) [l], [2] which was originally developed for Electroencephalograms. The algorithm uses a simple forward model representing a mixture of motor unit action potentials as seen across multiple channels. The parameters of this model are iteratively optimized for each component. Results are presented on both synthetic and experimental EMG data. The synthetic case has additive white noise and is compared with known components. The experimental EMG data was obtained using a custom linear electrode array designed for this study.

  12. Randomised controlled trial and economic analysis of an internet-based weight management programme: POWeR+ (Positive Online Weight Reduction).

    PubMed Central

    Little, Paul; Stuart, Beth; Hobbs, Fd Richard; Kelly, Jo; Smith, Emily R; Bradbury, Katherine J; Hughes, Stephanie; Smith, Peter Wf; Moore, Michael V; Lean, Mike Ej; Margetts, Barrie M; Byrne, Christopher D; Griffin, Simon; Davoudianfar, Mina; Hooper, Julie; Yao, Guiqing; Zhu, Shihua; Raftery, James; Yardley, Lucy

    2017-01-01

    BACKGROUND Behavioural counselling with intensive follow-up for obesity is effective, but in resource-constrained primary care settings briefer approaches are needed. OBJECTIVES To estimate the clinical effectiveness and cost-effectiveness of an internet-based behavioural intervention with regular face-to-face or remote support in primary care, compared with brief advice. DESIGN Individually randomised three-arm parallel trial with health economic evaluation and nested qualitative interviews. SETTING Primary care general practices in the UK. PARTICIPANTS Patients with a body mass index of ≥ 30 kg/m(2) (or ≥ 28 kg/m(2) with risk factors) identified from general practice records, recruited by postal invitation. INTERVENTIONS Positive Online Weight Reduction (POWeR+) is a 24-session, web-based weight management intervention completed over 6 months. Following online registration, the website randomly allocated participants using computer-generated random numbers to (1) the control intervention (n = 279), which had previously been demonstrated to be clinically effective (brief web-based information that minimised pressure to cut down foods, instead encouraging swaps to healthier choices and increasing fruit and vegetables, plus 6-monthly nurse weighing); (2) POWeR+F (n = 269), POWeR+ supplemented by face-to-face nurse support (up to seven contacts); or (3) POWeR+R (n = 270), POWeR+ supplemented by remote nurse support (up to five e-mails or brief telephone calls). MAIN OUTCOME MEASURES The primary outcome was a modelled estimate of average weight reduction over 12 months, assessed blind to group where possible, using multiple imputation for missing data. The secondary outcome was the number of participants maintaining a 5% weight reduction at 12 months. RESULTS A total of 818 eligible individuals were randomised using computer-generated random numbers. Weight change, averaged over 12 months, was documented in 666 out of 818 participants (81

  13. Randomised controlled trial and economic analysis of an internet-based weight management programme: POWeR+ (Positive Online Weight Reduction).

    PubMed

    Little, Paul; Stuart, Beth; Hobbs, Fd Richard; Kelly, Jo; Smith, Emily R; Bradbury, Katherine J; Hughes, Stephanie; Smith, Peter Wf; Moore, Michael V; Lean, Mike Ej; Margetts, Barrie M; Byrne, Christopher D; Griffin, Simon; Davoudianfar, Mina; Hooper, Julie; Yao, Guiqing; Zhu, Shihua; Raftery, James; Yardley, Lucy

    2017-01-01

    Behavioural counselling with intensive follow-up for obesity is effective, but in resource-constrained primary care settings briefer approaches are needed. To estimate the clinical effectiveness and cost-effectiveness of an internet-based behavioural intervention with regular face-to-face or remote support in primary care, compared with brief advice. Individually randomised three-arm parallel trial with health economic evaluation and nested qualitative interviews. Primary care general practices in the UK. Patients with a body mass index of ≥ 30 kg/m(2) (or ≥ 28 kg/m(2) with risk factors) identified from general practice records, recruited by postal invitation. Positive Online Weight Reduction (POWeR+) is a 24-session, web-based weight management intervention completed over 6 months. Following online registration, the website randomly allocated participants using computer-generated random numbers to (1) the control intervention (n = 279), which had previously been demonstrated to be clinically effective (brief web-based information that minimised pressure to cut down foods, instead encouraging swaps to healthier choices and increasing fruit and vegetables, plus 6-monthly nurse weighing); (2) POWeR+F (n = 269), POWeR+ supplemented by face-to-face nurse support (up to seven contacts); or (3) POWeR+R (n = 270), POWeR+ supplemented by remote nurse support (up to five e-mails or brief telephone calls). The primary outcome was a modelled estimate of average weight reduction over 12 months, assessed blind to group where possible, using multiple imputation for missing data. The secondary outcome was the number of participants maintaining a 5% weight reduction at 12 months. A total of 818 eligible individuals were randomised using computer-generated random numbers. Weight change, averaged over 12 months, was documented in 666 out of 818 participants (81%; control, n = 227; POWeR+F, n = 221; POWeR+R, n = 218). The control group maintained

  14. Costs and cost-effectiveness of a mental health intervention for war-affected young persons: decision analysis based on a randomized controlled trial.

    PubMed

    McBain, Ryan K; Salhi, Carmel; Hann, Katrina; Salomon, Joshua A; Kim, Jane J; Betancourt, Theresa S

    2016-05-01

    One billion children live in war-affected regions of the world. We conducted the first cost-effectiveness analysis of an intervention for war-affected youth in sub-Saharan Africa, as well as a broader cost analysis. The Youth Readiness Intervention (YRI) is a behavioural treatment for reducing functional impairment associated with psychological distress among war-affected young persons. A randomized controlled trial was conducted in Freetown, Sierra Leone, from July 2012 to July 2013. Participants (n = 436, aged 15-24) were randomized to YRI (n = 222) or care as usual (n = 214). Functional impairment was indexed by the World Health Organization Disability Assessment Scale; scores were converted to quality-adjusted life years (QALYs). An 'ingredients approach' estimated financial and economic costs, assuming a societal perspective. Incremental cost-effectiveness ratios (ICERs) were also expressed in terms of gains across dimensions of mental health and schooling. Secondary analyses explored whether intervention effects were largest among those worst-off (upper quartile) at baseline. Retention at 6-month follow-up was 85% (n = 371). The estimated economic cost of the intervention was $104 per participant. Functional impairment was lower among YRI recipients, compared with controls, following the intervention but not at 6-month follow-up, and yielded an ICER of $7260 per QALY gained. At 8-month follow-up, teachers' interviews indicated that YRI recipients observed higher school enrolment [P < 0.001, odds ratio (OR) 8.9], denoting a cost of $431 per additional school year gained, as well as better school attendance (P = 0.007, OR 34.9) and performance (P = 0.03, effect size = -1.31). Secondary analyses indicated that the intervention was cost-effective among those worst-off at baseline, yielding an ICER of $3564 per QALY gained. The YRI is not cost-effective at a willingness-to-pay threshold of three times average gross domestic product

  15. Costs and cost-effectiveness of a mental health intervention for war-affected young persons: decision analysis based on a randomized controlled trial

    PubMed Central

    McBain, Ryan K; Salhi, Carmel; Hann, Katrina; Salomon, Joshua A; Kim, Jane J; Betancourt, Theresa S

    2016-01-01

    Background: One billion children live in war-affected regions of the world. We conducted the first cost-effectiveness analysis of an intervention for war-affected youth in sub-Saharan Africa, as well as a broader cost analysis. Methods: The Youth Readiness Intervention (YRI) is a behavioural treatment for reducing functional impairment associated with psychological distress among war-affected young persons. A randomized controlled trial was conducted in Freetown, Sierra Leone, from July 2012 to July 2013. Participants (n = 436, aged 15–24) were randomized to YRI (n = 222) or care as usual (n = 214). Functional impairment was indexed by the World Health Organization Disability Assessment Scale; scores were converted to quality-adjusted life years (QALYs). An ‘ingredients approach’ estimated financial and economic costs, assuming a societal perspective. Incremental cost-effectiveness ratios (ICERs) were also expressed in terms of gains across dimensions of mental health and schooling. Secondary analyses explored whether intervention effects were largest among those worst-off (upper quartile) at baseline. Results: Retention at 6-month follow-up was 85% (n = 371). The estimated economic cost of the intervention was $104 per participant. Functional impairment was lower among YRI recipients, compared with controls, following the intervention but not at 6-month follow-up, and yielded an ICER of $7260 per QALY gained. At 8-month follow-up, teachers’ interviews indicated that YRI recipients observed higher school enrolment [P < 0.001, odds ratio (OR) 8.9], denoting a cost of $431 per additional school year gained, as well as better school attendance (P = 0.007, OR 34.9) and performance (P = 0.03, effect size = −1.31). Secondary analyses indicated that the intervention was cost-effective among those worst-off at baseline, yielding an ICER of $3564 per QALY gained. Conclusions: The YRI is not cost-effective at a willingness

  16. Multicyclic Controllable Twist Rotor Data Analysis

    NASA Technical Reports Server (NTRS)

    Wei, F. S.; Weisbrich, A. L.

    1979-01-01

    Rsults provide functional relationship between rotor performance, blade vibratory loads and dual control settings and indicate that multicyclic control produced significant reductions in blade flatwise bending moments and blade root actuator control loads. Higher harmonic terms of servo flap deflection were found to be most pronounced in flatwise bending moment, transmission vertical vibration and pitch link vibratory load equations. The existing test hardware represents a satisfactory configuration for demonstrating MCTR technology and defining a data base for additional wind tunnel testing.

  17. Aircraft Loss-of-Control Accident Analysis

    NASA Technical Reports Server (NTRS)

    Belcastro, Christine M.; Foster, John V.

    2010-01-01

    Loss of control remains one of the largest contributors to fatal aircraft accidents worldwide. Aircraft loss-of-control accidents are complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. Hence, there is no single intervention strategy to prevent these accidents. To gain a better understanding into aircraft loss-of-control events and possible intervention strategies, this paper presents a detailed analysis of loss-of-control accident data (predominantly from Part 121), including worst case combinations of causal and contributing factors and their sequencing. Future potential risks are also considered.

  18. A Pilot Randomised Controlled Trial of a School-Based Resilience Intervention to Prevent Depressive Symptoms for Young Adolescents with Autism Spectrum Disorder: A Mixed Methods Analysis.

    PubMed

    Mackay, Bethany A; Shochet, Ian M; Orr, Jayne A

    2017-08-02

    Despite increased depression in adolescents with Autism Spectrum Disorder (ASD), effective prevention approaches for this population are limited. A mixed methods pilot randomised controlled trial (N = 29) of the evidence-based Resourceful Adolescent Program-Autism Spectrum Disorder (RAP-A-ASD) designed to prevent depression was conducted in schools with adolescents with ASD in years 6 and 7. Quantitative results showed significant intervention effects on parent reports of adolescent coping self-efficacy (maintained at 6 month follow-up) but no effect on depressive symptoms or mental health. Qualitative outcomes reflected perceived improvements from the intervention for adolescents' coping self-efficacy, self-confidence, social skills, and affect regulation. Converging results remain encouraging given this population's difficulties coping with adversity, managing emotions and interacting socially which strongly influence developmental outcomes.

  19. Version Control in Project-Based Learning

    ERIC Educational Resources Information Center

    Milentijevic, Ivan; Ciric, Vladimir; Vojinovic, Oliver

    2008-01-01

    This paper deals with the development of a generalized model for version control systems application as a support in a range of project-based learning methods. The model is given as UML sequence diagram and described in detail. The proposed model encompasses a wide range of different project-based learning approaches by assigning a supervisory…

  20. Version Control in Project-Based Learning

    ERIC Educational Resources Information Center

    Milentijevic, Ivan; Ciric, Vladimir; Vojinovic, Oliver

    2008-01-01

    This paper deals with the development of a generalized model for version control systems application as a support in a range of project-based learning methods. The model is given as UML sequence diagram and described in detail. The proposed model encompasses a wide range of different project-based learning approaches by assigning a supervisory…

  1. Robust control-based object tracking.

    PubMed

    Qu, Wei; Schonfeld, Dan

    2008-09-01

    This correspondence presents a video tracking framework using control-based observer design. It unifies several kernel-based approaches into a consistent theoretical framework by modeling tracking as a recursive inverse problem. The framework relies on observability theory to handle the "singularity" problem and provides explicit criteria for kernel design and dynamics evaluation.

  2. Integrated tools for control-system analysis

    NASA Technical Reports Server (NTRS)

    Ostroff, Aaron J.; Proffitt, Melissa S.; Clark, David R.

    1989-01-01

    The basic functions embedded within a user friendly software package (MATRIXx) are used to provide a high level systems approach to the analysis of linear control systems. Various control system analysis configurations are assembled automatically to minimize the amount of work by the user. Interactive decision making is incorporated via menu options and at selected points, such as in the plotting section, by inputting data. There are five evaluations such as the singular value robustness test, singular value loop transfer frequency response, Bode frequency response, steady-state covariance analysis, and closed-loop eigenvalues. Another section describes time response simulations. A time response for random white noise disturbance is available. The configurations and key equations used for each type of analysis, the restrictions that apply, the type of data required, and an example problem are described. One approach for integrating the design and analysis tools is also presented.

  3. Population-based case-control association studies.

    PubMed

    Hancock, Dana B; Scott, William K

    2012-07-01

    This unit provides an overview of the design and analysis of population-based case-control studies of genetic risk factors for complex disease. Considerations specific to genetic studies are emphasized. The unit reviews basic study designs differentiating case-control studies from others, presents different genetic association strategies (candidate gene, genome-wide association, and high-throughput sequencing), introduces basic methods of statistical analysis for case-control data and approaches to combining case-control studies, and discusses measures of association and impact. Admixed populations, controlling for confounding (including population stratification), consideration of multiple loci and environmental risk factors, and complementary analyses of haplotypes, genes, and pathways are briefly discussed. Readers are referred to basic texts on epidemiology for more details on general conduct of case-control studies.

  4. Servo Control Using Wave-Based Method

    NASA Astrophysics Data System (ADS)

    Marek, O.

    The wave-based control of flexible mechanical systems has been developed. It is based on the idea of sending waves into the mechanical system, measuring of the incoming waves and avoiding the re-sending of these waves into the continuum again. This approach actually absorbs the energy coming from the system. It has been successfully applied for the number of simulations. This paper deals with the implementation of the wave-based control for experiments using servomotor. It particularly describes the implementation on Yaskawa servo-motor and its PLC system.

  5. A Higher Proportion of Metabolic Syndrome in Chinese Subjects with Sleep-Disordered Breathing: A Case-Control Study Based on Electrocardiogram-Derived Sleep Analysis

    PubMed Central

    Tseng, Ping-Huei; Lee, Pei-Lin; Hsu, Wei-Chung; Ma, Yan; Lee, Yi-Chia; Chiu, Han-Mo; Ho, Yi-Lwun; Chen, Ming-Fong; Wu, Ming-Shiang; Peng, Chung-Kang

    2017-01-01

    Objective The prevalence of metabolic syndrome (MS) has increased rapidly in Taiwan and worldwide. We aim to determine the association between sleep-disordered breathing (SDB) and MS in a Chinese general population. Methods This case-control study recruited subjects who have undergone a prospective electrocardiogram-based cardiopulmonary coupling (CPC) sleep spectrogram as part of the periodic health check-ups at the National Taiwan University Hospital. Comprehensive anthropometrics, blood biochemistry, prevalence of MS and its individual components were compared with Bonferroni correction between 40 subjects with SDB, defined as the CPC-derived apnea–hypopnea index (CPC-AHI) >5 event/hour and 80 age- and sex-matched controls, defined as CPC-AHI <1 event/hour. MS was diagnosed based on the Adult Treatment Panel III, with a modification of waist circumference for Asians. Results Subjects with SDB were more obese with larger waist circumferences (95.1±12.9 vs. 87.3±6.9, P < .001) and borderline higher BMI (27.0±4.9 vs. 24.3±2.5, P = .002). Waist circumference was independently associated with the presence of SDB after adjustment for BMI, systolic blood pressure and fasting blood glucose in multiple regression analyses. Subjects with SDB had a higher prevalence of central obesity (72.5% vs. 42.5%, P = .002), hyperglycemia (45.0% vs. 26.3%, P = .04), MS (45.0% vs. 22.5%, P = .01) and number of MS components (2.4 ± 1.6 vs. 1.7 ± 1.4, P = .01) than the control group. Waist circumference was significantly correlated with both CPC-AHI (r = .492, P = .0013) and PSG-AHI (r = .699, P < .0001) in the SDB group. Conclusions SDB was associated with a higher prevalence of MS and its individual components, notably central obesity, in a Chinese general population. Large-scale screening of high risk population with MS to identify subjects with SDB for appropriate management is warranted. PMID:28081171

  6. Simulation analysis of adaptive cruise prediction control

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Cui, Sheng Min

    2017-09-01

    Predictive control is suitable for multi-variable and multi-constraint system control.In order to discuss the effect of predictive control on the vehicle longitudinal motion, this paper establishes the expected spacing model by combining variable pitch spacing and the of safety distance strategy. The model predictive control theory and the optimization method based on secondary planning are designed to obtain and track the best expected acceleration trajectory quickly. Simulation models are established including predictive and adaptive fuzzy control. Simulation results show that predictive control can realize the basic function of the system while ensuring the safety. The application of predictive and fuzzy adaptive algorithm in cruise condition indicates that the predictive control effect is better.

  7. Development of Arduino based wireless control system

    NASA Astrophysics Data System (ADS)

    Sun, Zhuoxiong; Dyke, Shirley J.; Pena, Francisco; Wilbee, Alana

    2015-03-01

    Over the past few decades, considerable attention has been given to structural control systems to mitigate structural vibration under natural hazards such as earthquakes and extreme weather conditions. Traditional wired structural control systems often employ a large amount of cables for communication among sensors, controllers and actuators. In such systems, implementation of wired sensors is usually quite complicated and expensive, especially on large scale structures such as bridges and buildings. To reduce the laborious installation and maintenance cost, wireless control systems (WCSs) are considered as a novel approach for structural vibration control. In this work, a WCS is developed based on the open source Arduino platform. Low cost, low power wireless sensing and communication components are built on the Arduino platform. Structural control algorithms are embedded within the wireless sensor board for feedback control. The developed WCS is first validated through a series of tests. Next, numerical simulations are performed simulating wireless control of a 3-story shear structure equipped with a semi-active control device (MR damper). Finally, experimental studies are carried out implementing the WCS on the 3-story shear structure in the Intelligent Infrastructure Systems Lab (IISL). A hydraulic shake table is used to generate seismic ground motions. The control performance is evaluated with the impact of modeling uncertainties, measurement noises as well as time delay and data loss induced by the wireless network. The developed WCS is shown to be effective in controlling structural vibrations under several historical earthquake ground motions.

  8. GPC-Based Stable Reconfigurable Control

    NASA Technical Reports Server (NTRS)

    Soloway, Don; Shi, Jian-Jun; Kelkar, Atul

    2004-01-01

    This paper presents development of multi-input multi-output (MIMO) Generalized Pre-dictive Control (GPC) law and its application to reconfigurable control design in the event of actuator saturation. A Controlled Auto-Regressive Integrating Moving Average (CARIMA) model is used to describe the plant dynamics. The control law is derived using input-output description of the system and is also related to the state-space form of the model. The stability of the GPC control law without reconfiguration is first established using Riccati-based approach and state-space formulation. A novel reconfiguration strategy is developed for the systems which have actuator redundancy and are faced with actuator saturation type failure. An elegant reconfigurable control design is presented with stability proof. Several numerical examples are presented to demonstrate the application of various results.

  9. FIPA agent based network distributed control system

    SciTech Connect

    D. Abbott; V. Gyurjyan; G. Heyes; E. Jastrzembski; C. Timmer; E. Wolin

    2003-03-01

    A control system with the capabilities to combine heterogeneous control systems or processes into a uniform homogeneous environment is discussed. This dynamically extensible system is an example of the software system at the agent level of abstraction. This level of abstraction considers agents as atomic entities that communicate to implement the functionality of the control system. Agents' engineering aspects are addressed by adopting the domain independent software standard, formulated by FIPA. Jade core Java classes are used as a FIPA specification implementation. A special, lightweight, XML RDFS based, control oriented, ontology markup language is developed to standardize the description of the arbitrary control system data processor. Control processes, described in this language, are integrated into the global system at runtime, without actual programming. Fault tolerance and recovery issues are also addressed.

  10. Plasma Stabilization Based on Model Predictive Control

    NASA Astrophysics Data System (ADS)

    Sotnikova, Margarita

    The nonlinear model predictive control algorithms for plasma current and shape stabilization are proposed. Such algorithms are quite suitable for the situations when the plant to be controlled has essentially nonlinear dynamics. Besides that, predictive model based control algorithms allow to take into account a lot of requirements and constraints involved both on the controlled and manipulated variables. The significant drawback of the algorithms is that they require a lot of time to compute control input at each sampling instant. In this paper the model predictive control algorithms are demonstrated by the example of plasma vertical stabilization for ITER-FEAT tokamak. The tuning of parameters of algorithms is performed in order to decrease computational load.

  11. ASTEC: Controls analysis for personal computers

    NASA Technical Reports Server (NTRS)

    Downing, John P.; Bauer, Frank H.; Thorpe, Christopher J.

    1989-01-01

    The ASTEC (Analysis and Simulation Tools for Engineering Controls) software is under development at Goddard Space Flight Center (GSFC). The design goal is to provide a wide selection of controls analysis tools at the personal computer level, as well as the capability to upload compute-intensive jobs to a mainframe or supercomputer. The project is a follow-on to the INCA (INteractive Controls Analysis) program that has been developed at GSFC over the past five years. While ASTEC makes use of the algorithms and expertise developed for the INCA program, the user interface was redesigned to take advantage of the capabilities of the personal computer. The design philosophy and the current capabilities of the ASTEC software are described.

  12. Rate control algorithm based on frame complexity estimation for MVC

    NASA Astrophysics Data System (ADS)

    Yan, Tao; An, Ping; Shen, Liquan; Zhang, Zhaoyang

    2010-07-01

    Rate control has not been well studied for multi-view video coding (MVC). In this paper, we propose an efficient rate control algorithm for MVC by improving the quadratic rate-distortion (R-D) model, which reasonably allocate bit-rate among views based on correlation analysis. The proposed algorithm consists of four levels for rate bits control more accurately, of which the frame layer allocates bits according to frame complexity and temporal activity. Extensive experiments show that the proposed algorithm can efficiently implement bit allocation and rate control according to coding parameters.

  13. Agent-based forward analysis

    SciTech Connect

    Kerekes, Ryan A.; Jiao, Yu; Shankar, Mallikarjun; Potok, Thomas E.; Lusk, Rick M.

    2008-01-01

    We propose software agent-based "forward analysis" for efficient information retrieval in a network of sensing devices. In our approach, processing is pushed to the data at the edge of the network via intelligent software agents rather than pulling data to a central facility for processing. The agents are deployed with a specific query and perform varying levels of analysis of the data, communicating with each other and sending only relevant information back across the network. We demonstrate our concept in the context of face recognition using a wireless test bed comprised of PDA cell phones and laptops. We show that agent-based forward analysis can provide a significant increase in retrieval speed while decreasing bandwidth usage and information overload at the central facility. n

  14. Hand-Based Biometric Analysis

    NASA Technical Reports Server (NTRS)

    Bebis, George (Inventor); Amayeh, Gholamreza (Inventor)

    2015-01-01

    Hand-based biometric analysis systems and techniques are described which provide robust hand-based identification and verification. An image of a hand is obtained, which is then segmented into a palm region and separate finger regions. Acquisition of the image is performed without requiring particular orientation or placement restrictions. Segmentation is performed without the use of reference points on the images. Each segment is analyzed by calculating a set of Zernike moment descriptors for the segment. The feature parameters thus obtained are then fused and compared to stored sets of descriptors in enrollment templates to arrive at an identity decision. By using Zernike moments, and through additional manipulation, the biometric analysis is invariant to rotation, scale, or translation or an in put image. Additionally, the analysis utilizes re-use of commonly-seen terms in Zernike calculations to achieve additional efficiencies over traditional Zernike moment calculation.

  15. Hand-Based Biometric Analysis

    NASA Technical Reports Server (NTRS)

    Bebis, George

    2013-01-01

    Hand-based biometric analysis systems and techniques provide robust hand-based identification and verification. An image of a hand is obtained, which is then segmented into a palm region and separate finger regions. Acquisition of the image is performed without requiring particular orientation or placement restrictions. Segmentation is performed without the use of reference points on the images. Each segment is analyzed by calculating a set of Zernike moment descriptors for the segment. The feature parameters thus obtained are then fused and compared to stored sets of descriptors in enrollment templates to arrive at an identity decision. By using Zernike moments, and through additional manipulation, the biometric analysis is invariant to rotation, scale, or translation or an input image. Additionally, the analysis uses re-use of commonly seen terms in Zernike calculations to achieve additional efficiencies over traditional Zernike moment calculation.

  16. Optimal control concepts in design sensitivity analysis

    NASA Technical Reports Server (NTRS)

    Belegundu, Ashok D.

    1987-01-01

    A close link is established between open loop optimal control theory and optimal design by noting certain similarities in the gradient calculations. The resulting benefits include a unified approach, together with physical insights in design sensitivity analysis, and an efficient approach for simultaneous optimal control and design. Both matrix displacement and matrix force methods are considered, and results are presented for dynamic systems, structures, and elasticity problems.

  17. Effect of a smoking ban and school-based prevention and control policies on adolescent smoking in Spain: a multilevel analysis.

    PubMed

    Galán, Iñaki; Díez-Gañán, Lucía; Gandarillas, Ana; Mata, Nelva; Cantero, Jose Luis; Durbán, María

    2012-12-01

    We evaluated the impact of a smoking ban in schools and of school-based smoking prevention and control policies on adolescent smoking. Annual surveys carried out between 2001 and 2005 that were representative of students in the 4th year of secondary education in the Madrid region, with 203 schools and 9127 students participating. The student questionnaire gathered information about personal and family variables. The contextual factors were: the periods before (years 2001-2002) and after the law; and through a survey of school management boards: compliance with the law, policy reflected in the school regulations, existence of complaints against smoking, and undertaking of educational activities regarding smoking. Multilevel logistic regression models were constructed with two dependent variables: current smoking and the proportion giving up smoking. Smoking declined in 2003, the first year after the law came into force (Odds ratio: 0.80; CI 95%: 0.66-0.96), and this decline was maintained in 2005. By contrast, smoking increased in those schools that did not undertake educational programmes regarding smoking (Odds ratio: 1.34; CI 95%: 1.13-1.59), and in those that received complaints about smoking (Odds ratio: 1.12; CI 95%: 0.96-1.29). This association is partly due to the effect of the increase in giving up smoking. The inclusion of contextual variables into the model with the individual factors reduces the variability of smoking between schools by 32.6%. In summary, the coming into force of a law banning smoking in schools, and the implementing of educational policies for the prevention and control of smoking are related to a lower risk of adolescent smoking.

  18. Probabilistic performance-based design for high performance control systems

    NASA Astrophysics Data System (ADS)

    Micheli, Laura; Cao, Liang; Gong, Yongqiang; Cancelli, Alessandro; Laflamme, Simon; Alipour, Alice

    2017-04-01

    High performance control systems (HPCS) are advanced damping systems capable of high damping performance over a wide frequency bandwidth, ideal for mitigation of multi-hazards. They include active, semi-active, and hybrid damping systems. However, HPCS are more expensive than typical passive mitigation systems, rely on power and hardware (e.g., sensors, actuators) to operate, and require maintenance. In this paper, a life cycle cost analysis (LCA) approach is proposed to estimate the economic benefit these systems over the entire life of the structure. The novelty resides in the life cycle cost analysis in the performance based design (PBD) tailored to multi-level wind hazards. This yields a probabilistic performance-based design approach for HPCS. Numerical simulations are conducted on a building located in Boston, MA. LCA are conducted for passive control systems and HPCS, and the concept of controller robustness is demonstrated. Results highlight the promise of the proposed performance-based design procedure.

  19. Optimization-based controller design for rotorcraft

    NASA Technical Reports Server (NTRS)

    Tsing, N.-K.; Fan, M. K. H.; Barlow, J.; Tits, A. L.; Tischler, M. B.

    1993-01-01

    An optimization-based methodology for linear control system design is outlined by considering the design of a controller for a UH-60 rotorcraft in hover. A wide range of design specifications is taken into account: internal stability, decoupling between longitudinal and lateral motions, handling qualities, and rejection of windgusts. These specifications are investigated while taking into account physical limitations in the swashplate displacements and rates of displacement. The methodology crucially relies on user-machine interaction for tradeoff exploration.

  20. Resume and analysis of NACA lateral control research

    NASA Technical Reports Server (NTRS)

    Weick, Fred E; Jones, Robert T

    1937-01-01

    An analysis of the principal results of recent NACA lateral control research is made by utilizing the experience and progress gained during the course of the investigation. Two things are considered of primary importance in judging the effectiveness of different control devices: the (calculated) banking and yawing motion of a typical small airplane caused by a deflection of the control, and the stick force required to produce this deflection. The report includes a table in which a number of different lateral control devices are compared on these bases.

  1. Flexible manipulator control experiments and analysis

    NASA Technical Reports Server (NTRS)

    Yurkovich, S.; Ozguner, U.; Tzes, A.; Kotnik, P. T.

    1987-01-01

    Modeling and control design for flexible manipulators, both from an experimental and analytical viewpoint, are described. From the application perspective, an ongoing effort within the laboratory environment at the Ohio State University, where experimentation on a single link flexible arm is underway is described. Several unique features of this study are described here. First, the manipulator arm is slewed by a direct drive dc motor and has a rigid counterbalance appendage. Current experimentation is from two viewpoints: (1) rigid body slewing and vibration control via actuation with the hub motor, and (2) vibration suppression through the use of structure-mounted proof-mass actuation at the tip. Such an application to manipulator control is of interest particularly in design of space-based telerobotic control systems, but has received little attention to date. From an analytical viewpoint, parameter estimation techniques within the closed-loop for self-tuning adaptive control approaches are discussed. Also introduced is a control approach based on output feedback and frequency weighting to counteract effects of spillover in reduced-order model design. A model of the flexible manipulator based on experimental measurements is evaluated for such estimation and control approaches.

  2. Disturbance observer based hierarchical control of coaxial-rotor UAV.

    PubMed

    Mokhtari, M Rida; Cherki, Brahim; Braham, Amal Choukchou

    2017-03-01

    This paper propose an hierarchical controller based on a new disturbance observer with finite time convergence (FTDO) to solve the path tracking of a small coaxial-rotor-typs Unmanned Aerial Vehicles (UAVs) despite of unknown aerodynamic efforts. The hierarchical control technique is used to separate the flight control problem into an inner loop that controls attitude and an outer loop that controls the thrust force acting on the vehicle. The new disturbance observer with finite time convergence is intergated to online estimate the unknown uncertainties and disturbances and to actively compensate them in finite time.The analysis further extends to the design of a control law that takes the disturbance estimation procedure into account. Numerical simulations are carried out to demonstrate the efficiency of the proposed control strategy. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  3. DNA-based control of protein activity

    PubMed Central

    Engelen, W.; Janssen, B. M. G.

    2016-01-01

    DNA has emerged as a highly versatile construction material for nanometer-sized structures and sophisticated molecular machines and circuits. The successful application of nucleic acid based systems greatly relies on their ability to autonomously sense and act on their environment. In this feature article, the development of DNA-based strategies to dynamically control protein activity via oligonucleotide triggers is discussed. Depending on the desired application, protein activity can be controlled by directly conjugating them to an oligonucleotide handle, or expressing them as a fusion protein with DNA binding motifs. To control proteins without modifying them chemically or genetically, multivalent ligands and aptamers that reversibly inhibit their function provide valuable tools to regulate proteins in a noncovalent manner. The goal of this feature article is to give an overview of strategies developed to control protein activity via oligonucleotide-based triggers, as well as hurdles yet to be taken to obtain fully autonomous systems that interrogate, process and act on their environments by means of DNA-based protein control. PMID:26812623

  4. Developing stereo image based robot control system

    NASA Astrophysics Data System (ADS)

    Suprijadi, Pambudi, I. R.; Woran, M.; Naa, C. F.; Srigutomo, W.

    2015-04-01

    Application of image processing is developed in various field and purposes. In the last decade, image based system increase rapidly with the increasing of hardware and microprocessor performance. Many fields of science and technology were used this methods especially in medicine and instrumentation. New technique on stereovision to give a 3-dimension image or movie is very interesting, but not many applications in control system. Stereo image has pixel disparity information that is not existed in single image. In this research, we proposed a new method in wheel robot control system using stereovision. The result shows robot automatically moves based on stereovision captures.

  5. Predictor-Based Model Reference Adaptive Control

    NASA Technical Reports Server (NTRS)

    Lavretsky, Eugene; Gadient, Ross; Gregory, Irene M.

    2009-01-01

    This paper is devoted to robust, Predictor-based Model Reference Adaptive Control (PMRAC) design. The proposed adaptive system is compared with the now-classical Model Reference Adaptive Control (MRAC) architecture. Simulation examples are presented. Numerical evidence indicates that the proposed PMRAC tracking architecture has better than MRAC transient characteristics. In this paper, we presented a state-predictor based direct adaptive tracking design methodology for multi-input dynamical systems, with partially known dynamics. Efficiency of the design was demonstrated using short period dynamics of an aircraft. Formal proof of the reported PMRAC benefits constitute future research and will be reported elsewhere.

  6. Developing stereo image based robot control system

    SciTech Connect

    Suprijadi,; Pambudi, I. R.; Woran, M.; Naa, C. F; Srigutomo, W.

    2015-04-16

    Application of image processing is developed in various field and purposes. In the last decade, image based system increase rapidly with the increasing of hardware and microprocessor performance. Many fields of science and technology were used this methods especially in medicine and instrumentation. New technique on stereovision to give a 3-dimension image or movie is very interesting, but not many applications in control system. Stereo image has pixel disparity information that is not existed in single image. In this research, we proposed a new method in wheel robot control system using stereovision. The result shows robot automatically moves based on stereovision captures.

  7. Comparative phylogeography between the ermine Mustela erminea and the least weasel M. nivalis of Palaearctic and Nearctic regions, based on analysis of mitochondrial DNA control region sequences.

    PubMed

    Kurose, Naoko; Abramov, Alexei V; Masuda, Ryuichi

    2005-10-01

    Phylogeography of the ermine Mustela erminea and the least weasel M. nivalis from Palaearctic and Nearctic regions were investigated based on mitochondrial DNA control region sequences. Mustela erminea exhibited a very low level of genetic variation, and geographic structures among populations were unclear. This may indicate that M. erminea recently reoccupied a wide territory in Eurasia following the last glacial retreat. In comparison with M. erminea, genetic variations within and among populations of M. nivalis were much greater. Molecular phylogenetic relationships showed that two lineages of M. nivalis occurred in the Holarctic region: one spread from the Eurasian region to North America, and the other occurred in south-eastern Europe, the Caucasus and Central Asia. The results suggest either mitochondrial DNA introgression among populations of south-eastern Europe, the Caucasus and Central Asia, or ancestral polymorphisms remaining in those populations. Contrastive phylogeographic patterns between the two mustelid species could reflect differences of their migration histories in Eurasia after the last glacial age.

  8. Determination of Zinc-Based Additives in Lubricating Oils by Flow-Injection Analysis with Flame-AAS Detection Exploiting Injection with a Computer-Controlled Syringe

    PubMed Central

    Pignalosa, Gustavo; Cabrera, Noel

    2005-01-01

    A flow-injection system is proposed for the determination of metal-based additives in lubricating oils. The system, operating under computer control uses a motorised syringe for measuring and injecting the oil sample (200 μL) in a kerosene stream, where it is dispersed by means of a packed mixing reactor and carried to an atomic absorption spectrometer which is used as detector. Zinc was used as model analyte. Two different systems were evaluated, one for low concentrations (range 0–10 ppm) and the second capable of providing higher dilution rates for high concentrations (range 0.02%–0.2% w/w). The sampling frequency was about 30 samples/h. Calibration curves fitted a second-degree regression model (r 2 = 0.996). Commercial samples with high and low zinc levels were analysed by the proposed method and the results were compared with those obtained with the standard ASTM method. The t test for mean values showed no significant differences at the 95% confidence level. Precision (RSD%) was better than 5% (2% typical) for the high concentrations system. The carryover between successive injections was found to be negligible. PMID:18924720

  9. A coordinate-based ALE functional MRI meta-analysis of brain activation during verbal fluency tasks in healthy control subjects

    PubMed Central

    2014-01-01

    Background The processing of verbal fluency tasks relies on the coordinated activity of a number of brain areas, particularly in the frontal and temporal lobes of the left hemisphere. Recent studies using functional magnetic resonance imaging (fMRI) to study the neural networks subserving verbal fluency functions have yielded divergent results especially with respect to a parcellation of the inferior frontal gyrus for phonemic and semantic verbal fluency. We conducted a coordinate-based activation likelihood estimation (ALE) meta-analysis on brain activation during the processing of phonemic and semantic verbal fluency tasks involving 28 individual studies with 490 healthy volunteers. Results For phonemic as well as for semantic verbal fluency, the most prominent clusters of brain activation were found in the left inferior/middle frontal gyrus (LIFG/MIFG) and the anterior cingulate gyrus. BA 44 was only involved in the processing of phonemic verbal fluency tasks, BA 45 and 47 in the processing of phonemic and semantic fluency tasks. Conclusions Our comparison of brain activation during the execution of either phonemic or semantic verbal fluency tasks revealed evidence for spatially different activation in BA 44, but not other regions of the LIFG/LMFG (BA 9, 45, 47) during phonemic and semantic verbal fluency processing. PMID:24456150

  10. A coordinate-based ALE functional MRI meta-analysis of brain activation during verbal fluency tasks in healthy control subjects.

    PubMed

    Wagner, Stefanie; Sebastian, Alexandra; Lieb, Klaus; Tüscher, Oliver; Tadić, André

    2014-01-24

    The processing of verbal fluency tasks relies on the coordinated activity of a number of brain areas, particularly in the frontal and temporal lobes of the left hemisphere. Recent studies using functional magnetic resonance imaging (fMRI) to study the neural networks subserving verbal fluency functions have yielded divergent results especially with respect to a parcellation of the inferior frontal gyrus for phonemic and semantic verbal fluency. We conducted a coordinate-based activation likelihood estimation (ALE) meta-analysis on brain activation during the processing of phonemic and semantic verbal fluency tasks involving 28 individual studies with 490 healthy volunteers. For phonemic as well as for semantic verbal fluency, the most prominent clusters of brain activation were found in the left inferior/middle frontal gyrus (LIFG/MIFG) and the anterior cingulate gyrus. BA 44 was only involved in the processing of phonemic verbal fluency tasks, BA 45 and 47 in the processing of phonemic and semantic fluency tasks. Our comparison of brain activation during the execution of either phonemic or semantic verbal fluency tasks revealed evidence for spatially different activation in BA 44, but not other regions of the LIFG/LMFG (BA 9, 45, 47) during phonemic and semantic verbal fluency processing.

  11. Performance analysis of Integrated Communication and Control System networks

    NASA Technical Reports Server (NTRS)

    Halevi, Y.; Ray, A.

    1990-01-01

    This paper presents statistical analysis of delays in Integrated Communication and Control System (ICCS) networks that are based on asynchronous time-division multiplexing. The models are obtained in closed form for analyzing control systems with randomly varying delays. The results of this research are applicable to ICCS design for complex dynamical processes like advanced aircraft and spacecraft, autonomous manufacturing plants, and chemical and processing plants.

  12. Performance analysis of Integrated Communication and Control System networks

    NASA Technical Reports Server (NTRS)

    Halevi, Y.; Ray, A.

    1990-01-01

    This paper presents statistical analysis of delays in Integrated Communication and Control System (ICCS) networks that are based on asynchronous time-division multiplexing. The models are obtained in closed form for analyzing control systems with randomly varying delays. The results of this research are applicable to ICCS design for complex dynamical processes like advanced aircraft and spacecraft, autonomous manufacturing plants, and chemical and processing plants.

  13. Applied Behavior Analysis and Statistical Process Control?

    ERIC Educational Resources Information Center

    Hopkins, B. L.

    1995-01-01

    Incorporating statistical process control (SPC) methods into applied behavior analysis is discussed. It is claimed that SPC methods would likely reduce applied behavior analysts' intimate contacts with problems and would likely yield poor treatment and research decisions. Cases and data presented by Pfadt and Wheeler (1995) are cited as examples.…

  14. Applied Behavior Analysis and Statistical Process Control?

    ERIC Educational Resources Information Center

    Hopkins, B. L.

    1995-01-01

    Incorporating statistical process control (SPC) methods into applied behavior analysis is discussed. It is claimed that SPC methods would likely reduce applied behavior analysts' intimate contacts with problems and would likely yield poor treatment and research decisions. Cases and data presented by Pfadt and Wheeler (1995) are cited as examples.…

  15. Integrated analysis and design for controlled nonlinear multibody systems

    NASA Technical Reports Server (NTRS)

    Wu, Shih-Chin; Juang, Jer-Nan; Belvin, W. Keith; Woodard, Stanley E.

    1991-01-01

    A hybrid approach for integrated analysis and design of nonlinear multibody systems is proposed. Based on the approach, a general-purpose design tool is developed for nonlinear dynamic systems subjected to nonlinear design constraints. For analysis purposes, second-order nonlinear equations of motion of the system are automatically generated using general-purpose multibody formulations. Once the equations are solved, they are written in first-order form to take advantage of the first-order formulations of design sensitivity analysis for dynamic systems. A nonlinear programming technique is then used to optimize the nonlinear systems, such that a nonlinear cost function is minimized and performance constraints are satisfied. The approach proved to be very general and useful for design and analysis of controlled multibody systems. The approach is applied to the design of passive dynamic controllers for slewing control of multibody systems.

  16. Composite disturbance rejection control based on generalized extended state observer.

    PubMed

    Zhang, Yanjun; Zhang, Jun; Wang, Lu; Su, Jianbo

    2016-07-01

    Traditional extended state observer (ESO) design method does not focus on analysis of system reconstruction strategy. The prior information of the controlled system cannot be used for ESO implementation to improve the control accuracy. In this paper, composite disturbance rejection control strategy is proposed based on generalized ESO. First, the disturbance rejection performance of traditional ESO is analyzed to show the essence of the reconstruction strategy. Then, the system is reconstructed based on the equivalent disturbance model. The generalized ESO is proposed based on the reconstructed model, while convergence of the proposed ESO is analyzed along with the outer loop feedback controller. Simulation results on a second order mechanical system show that the proposed generalized ESO can deal with the external disturbance with known model successfully. Experiment of attitude tracking task on an aircraft is also carried out to show the effectiveness of the proposed method. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Quantitative Analysis of Variability and Uncertainty in Environmental Data and Models. Volume 2. Performance, Emissions, and Cost of Combustion-Based NOx Controls for Wall and Tangential Furnace Coal-Fired Power Plants

    SciTech Connect

    Frey, H. Christopher; Tran, Loan K.

    1999-04-30

    This is Volume 2 of a two-volume set of reports describing work conducted at North Carolina State University sponsored by Grant Number DE-FG05-95ER30250 by the U.S. Department of Energy. The title of the project is “Quantitative Analysis of Variability and Uncertainty in Acid Rain Assessments.” The work conducted under sponsorship of this grant pertains primarily to two main topics: (1) development of new methods for quantitative analysis of variability and uncertainty applicable to any type of model; and (2) analysis of variability and uncertainty in the performance, emissions, and cost of electric power plant combustion-based NOx control technologies. These two main topics are reported separately in Volumes 1 and 2.

  18. Lorentz Force Based Satellite Attitude Control

    NASA Astrophysics Data System (ADS)

    Giri, Dipak Kumar; Sinha, Manoranjan

    2016-07-01

    Since the inception of attitude control of a satellite, various active and passive control strategies have been developed. These include using thrusters, momentum wheels, control moment gyros and magnetic torquers. In this present work, a new technique named Lorentz force based Coulombic actuators for the active control is proposed. This method uses electrostatic charged shells, which interact with the time varying earth's magnetic field to establish a full three axes control of the satellite. It is shown that the proposed actuation mechanism is similar to a satellite actuated by magnetic coils except that the resultant magnetic moment vanishes under two different conditions. The equation for the required charges on the the Coulomb shells attached to the satellite body axes is derived, which is in turn used to find the available control torque for actuating the satellite along the orbit. Stability of the proposed system for very high initial angular velocity and exponential stability about the origin are proved for a proportional-differential control input. Simulations are carried out to show the efficacy of the proposed system for the attitude control of the earth-pointing satellite.

  19. Effect of a community-based diabetes self-management empowerment program on mental health-related quality of life: a causal mediation analysis from a randomized controlled trial.

    PubMed

    Sugiyama, Takehiro; Steers, William Neil; Wenger, Neil S; Duru, Obidiugwu Kenrik; Mangione, Carol M

    2015-03-22

    There is a paucity of evidence supporting the effectiveness of diabetes self-management education (DSME) in improving mental health-related quality of life (HRQoL) for African American and Latinos. Also, among studies supporting the favorable effects of DSME on mental HRQoL, the direct effect of DSME that is independent of improved glycemic control has never been investigated. The objectives of this study were to investigate the effect of community-based DSME intervention targeting empowerment on mental HRQoL and to determine whether the effect is direct or mediated by glycemic control. We conducted secondary analyses of data from the Diabetes Self-Care Study, a randomized controlled trial of a community-based DSME intervention. Study participants (n = 516) were African Americans and Latinos 55 years or older with poorly controlled diabetes (HbA1c ≥ 8.0%) recruited from senior centers and churches in Los Angeles. The intervention group received six weekly small-group self-care sessions based on the empowerment model. The control group received six lectures on unrelated geriatrics topics. The primary outcome variable in this secondary analysis was the change in Mental Component Summary score (MCS-12) from the SF-12 Health Survey between baseline and six-month follow-up. We used the change in HbA1c during the study period as the main mediator of interest in our causal mediation analysis. Additionally, possible mediations via social support and perceived empowerment attributable to the program were examined. MCS-12 increased by 1.4 points on average in the intervention group and decreased by 0.2 points in the control group (difference-in-change: 1.6 points, 95% CI: 0.1 to 3.2). In the causal mediation analysis, the intervention had a direct effect on MCS-12 improvement (1.7 points, 95% CI: 0.2 to 3.2) with no indirect effects mediated via HbA1c change (-0.1 points, 95% CI: -0.4 to 0.1), social support (0.1 points), and perception of empowerment (0.1 points

  20. Analysis of precursors to multiply controlled problem behavior: A replication.

    PubMed

    Borlase, Megan A; Vladescu, Jason C; Kisamore, April N; Reeve, Sharon A; Fetzer, Jamie L

    2017-07-01

    We replicated Fritz, Iwata, Hammond, and Bloom (2013) by evaluating the efficacy of an experimental methodology to identify precursors to aggression displayed by an adolescent with autism spectrum disorder. Using their trial-based precursor analysis, we identified seven precursors to aggression. Next, we compared the outcomes of separate precursor and aggression functional analyses and showed that both precursors and aggression were multiply controlled by the same variables. © 2017 Society for the Experimental Analysis of Behavior.

  1. Military Space Control: An Intuitive Analysis

    DTIC Science & Technology

    2004-04-01

    information dominance is the impetus for an increasing military dependence on space services. This reliance on space systems is compelling military decision makers to make key strategic choices about the future of space control. The purpose of this paper is to analyze major aspects of military space control strategy and determine if U.S. initiatives are on track to meet the needs of the warfighter. To analyze U.S. military space control strategy, this research takes an intuitive approach based on a methodology introduced by Newman, Logan, and Hegarty in their book,

  2. Evaluating control displays with the Engineering Control Analysis Tool (ECAT)

    SciTech Connect

    Plott, B.

    2006-07-01

    In the Nuclear Power Industry increased use of automated sensors and advanced control systems is expected to reduce and/or change manning requirements. However, critical questions remain regarding the extent to which safety will be compromised if the cognitive workload associated with monitoring multiple automated systems is increased. Can operators/engineers maintain an acceptable level of performance if they are required to supervise multiple automated systems and respond appropriately to off-normal conditions? The interface to/from the automated systems must provide the information necessary for making appropriate decisions regarding intervention in the automated process, but be designed so that the cognitive load is neither too high nor too low for the operator who is responsible for the monitoring and decision making. This paper will describe a new tool that was developed to enhance the ability of human systems integration (HSI) professionals and systems engineers to identify operational tasks in which a high potential for human overload and error can be expected. The tool is entitled the Engineering Control Analysis Tool (ECAT). ECAT was designed and developed to assist in the analysis of: Reliability Centered Maintenance (RCM), operator task requirements, human error probabilities, workload prediction, potential control and display problems, and potential panel layout problems. (authors)

  3. Are signalized intersections with cycle tracks safer? A case-control study based on automated surrogate safety analysis using video data.

    PubMed

    Zangenehpour, Sohail; Strauss, Jillian; Miranda-Moreno, Luis F; Saunier, Nicolas

    2016-01-01

    Cities in North America have been building bicycle infrastructure, in particular cycle tracks, with the intention of promoting urban cycling and improving cyclist safety. These facilities have been built and expanded but very little research has been done to investigate the safety impacts of cycle tracks, in particular at intersections, where cyclists interact with turning motor-vehicles. Some safety research has looked at injury data and most have reached the conclusion that cycle tracks have positive effects of cyclist safety. The objective of this work is to investigate the safety effects of cycle tracks at signalized intersections using a case-control study. For this purpose, a video-based method is proposed for analyzing the post-encroachment time as a surrogate measure of the severity of the interactions between cyclists and turning vehicles travelling in the same direction. Using the city of Montreal as the case study, a sample of intersections with and without cycle tracks on the right and left sides of the road were carefully selected accounting for intersection geometry and traffic volumes. More than 90h of video were collected from 23 intersections and processed to obtain cyclist and motor-vehicle trajectories and interactions. After cyclist and motor-vehicle interactions were defined, ordered logit models with random effects were developed to evaluate the safety effects of cycle tracks at intersections. Based on the extracted data from the recorded videos, it was found that intersection approaches with cycle tracks on the right are safer than intersection approaches with no cycle track. However, intersections with cycle tracks on the left compared to no cycle tracks seem to be significantly safer. Results also identify that the likelihood of a cyclist being involved in a dangerous interaction increases with increasing turning vehicle flow and decreases as the size of the cyclist group arriving at the intersection increases. The results highlight the

  4. Multi-axis control based on movement control cards in NC systems

    NASA Astrophysics Data System (ADS)

    Jiang, Tingbiao; Wei, Yunquan

    2005-12-01

    Today most movement control cards need special control software of topper computers and are only suitable for fixed-axis controls. Consequently, the number of axes which can be controlled is limited. Advanced manufacture technology develops at a very high speed, and that development brings forth. New requirements for movement control in mechanisms and electronics. This paper introduces products of the 5th generation of movement control cards, PMAC 2A-PC/104, made by the Delta Tau Company in the USA. Based on an analysis of PMAC 2A-PC/104, this paper first describes two aspects relevant to the hardware structure of movement control cards and the interrelated software of the topper computers. Then, two methods are presented for solving these problems. The first method is to set limit switches on the movement control cards; all of them can be used to control each moving axis. The second method is to program applied software with existing programming language (for example, VC ++, Visual Basic, Delphi, and so forth). This program is much easier to operate and expand by its users. By using a limit switch, users can choose different axes in movement control cards. Also, users can change parts of the parameters in the control software of topper computers to realize different control axes. Combining these 2 methods proves to be convenient for realizing multi-axis control in numerical control systems.

  5. OTEC plant response and control analysis

    SciTech Connect

    Owens, W.L.

    1982-08-01

    An analysis is presented which allows prediction of closed-cycle OTEC power plant system response and control. Two basic operational control schemes are presented, which are primarily related to the type of seawater pumps employed. Variable flow seawater pumps allow optimization of the OTEC thermal-cycle state points for maximization of net generated power. Constant flow pumps are cheaper and simpler, but do not allow direct control over the evaporator and condenser operating temperatures. A system of nonlinear differential equations representing the basic elements of a constant seawater flow OTEC plant with turbine bypass flow control has been formulated for computer solution. Typical normalized response curves are presented for pressures, temperatures, mass flow rates, and generator speed for a small-scale, 50-kW OTEC plant design.

  6. Task analysis of laparoscopic camera control schemes.

    PubMed

    Ellis, R Darin; Munaco, Anthony J; Reisner, Luke A; Klein, Michael D; Composto, Anthony M; Pandya, Abhilash K; King, Brady W

    2016-12-01

    Minimally invasive surgeries rely on laparoscopic camera views to guide the procedure. Traditionally, an expert surgical assistant operates the camera. In some cases, a robotic system is used to help position the camera, but the surgeon is required to direct all movements of the system. Some prior research has focused on developing automated robotic camera control systems, but that work has been limited to rudimentary control schemes due to a lack of understanding of how the camera should be moved for different surgical tasks. This research used task analysis with a sample of eight expert surgeons to discover and document several salient methods of camera control and their related task contexts. Desired camera placements and behaviours were established for two common surgical subtasks (suturing and knot tying). The results can be used to develop better robotic control algorithms that will be more responsive to surgeons' needs. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  7. REVIEW OF NRC APPROVED DIGITAL CONTROL SYSTEMS ANALYSIS

    SciTech Connect

    D.W. Markman

    1999-09-17

    Preliminary design concepts for the proposed Subsurface Repository at Yucca Mountain indicate extensive reliance on modern, computer-based, digital control technologies. The purpose of this analysis is to investigate the degree to which the U. S. Nuclear Regulatory Commission (NRC) has accepted and approved the use of digital control technology for safety-related applications within the nuclear power industry. This analysis reviews cases of existing digitally-based control systems that have been approved by the NRC. These cases can serve as precedence for using similar types of digitally-based control technologies within the Subsurface Repository. While it is anticipated that the Yucca Mountain Project (YMP) will not contain control systems as complex as those required for a nuclear power plant, the review of these existing NRC approved applications will provide the YMP with valuable insight into the NRCs review process and design expectations for safety-related digital control systems. According to the YMP Compliance Program Guidance, portions of various NUREGS, Regulatory Guidelines, and nuclear IEEE standards the nuclear power plant safety related concept would be applied to some of the designs on a case-by-case basis. This analysis will consider key design methods, capabilities, successes, and important limitations or problems of selected control systems that have been approved for use in the Nuclear Power industry. An additional purpose of this analysis is to provide background information in support of further development of design criteria for the YMP. The scope and primary objectives of this analysis are to: (1) Identify and research the extent and precedence of digital control and remotely operated systems approved by the NRC for the nuclear power industry. Help provide a basis for using and relying on digital technologies for nuclear related safety critical applications. (2) Identify the basic control architecture and methods of key digital control

  8. Fuzzy logic-based flight control system design

    NASA Astrophysics Data System (ADS)

    Nho, Kyungmoon

    The application of fuzzy logic to aircraft motion control is studied in this dissertation. The self-tuning fuzzy techniques are developed by changing input scaling factors to obtain a robust fuzzy controller over a wide range of operating conditions and nonlinearities for a nonlinear aircraft model. It is demonstrated that the properly adjusted input scaling factors can meet the required performance and robustness in a fuzzy controller. For a simple demonstration of the easy design and control capability of a fuzzy controller, a proportional-derivative (PD) fuzzy control system is compared to the conventional controller for a simple dynamical system. This thesis also describes the design principles and stability analysis of fuzzy control systems by considering the key features of a fuzzy control system including the fuzzification, rule-base and defuzzification. The wing-rock motion of slender delta wings, a linear aircraft model and the six degree of freedom nonlinear aircraft dynamics are considered to illustrate several self-tuning methods employing change in input scaling factors. Finally, this dissertation is concluded with numerical simulation of glide-slope capture in windshear demonstrating the robustness of the fuzzy logic based flight control system.

  9. Effects of S-1 Combined with Radiotherapy in the Treatment of Nasopharyngeal Cancer: A Meta-analysis Based on Randomized Controlled Trials.

    PubMed

    Fengtong, Jin; Jiangtao, Fu; Yating, Wang; Lili, Wu; Jianbo, Chen; Xiaofei, Wang

    2017-01-01

    The aim of this meta-analysis was to evaluate the effects and toxicity of S-1 combined with radiotherapy in the treatment of nasopharyngeal cancer (NPC). Through a search of the databases of PubMed, Embase, the Chinese Biomedicine Database (CBM), China National Knowledge Infrastructure (CNKI), Wanfang system and Chongqing VIP Information (CQVIP), the efficacy and side effects data of S-1 combined with radiotherapy in the treatment of NPC patients from open published randomized controlled trials (RCTs) were collected. The pooled complete response (CR), partial response (PR), objective response rate (ORR), 2-year survival rate and treatment related toxicity were analyzed by Stata12.0 software. Eight RCTs with 599 cases were included and analyzed in this meta-analysis. The general quality of the 8 studies were deemed as having moderate risk of bias. Adequate sequence generation was reported in 4 studies. Incomplete outcome data address was reported in 7 publications. Five studies indicated to be free of selective reporting. Seven studies reported the treatment complete response (CR) between S-1 combined with radiotherapy and radiotherapy alone. With significant heterogeneity, the data was pooled by random effect model. The pooled results indicated that S-1 combined with radiotherapy can significant increase the CR rate compared to radiotherapy alone (RR=1.52, 95%CI:1.33-1.74, P<0.05). Eight studies reported the partial response (PR) rate between the combined treatment and radiotherapy alone. The pooled results showed that there was no statistical difference for PR between combined treatment and radiotherapy alone (RR=0.85, 95%CI:0.62-1.16, P>0.05). For the effect size of objective response rate (ORR), pooled results indicated that S-1 combined with radiotherapy can significantly increased the ORR by random effect model (RR=1.39, 95%CI:1.23-1.57, P<0.05). The pooled results showed that S-1 combined with radiotherapy significant increase the risk of developing bone

  10. Controllable set analysis for planetary landing under model uncertainties

    NASA Astrophysics Data System (ADS)

    Long, Jiateng; Gao, Ai; Cui, Pingyuan

    2015-07-01

    Controllable set analysis is a beneficial method in planetary landing mission design by feasible entry state selection in order to achieve landing accuracy and satisfy entry path constraints. In view of the severe impact of model uncertainties on planetary landing safety and accuracy, the purpose of this paper is to investigate the controllable set under uncertainties between on-board model and the real situation. Controllable set analysis under model uncertainties is composed of controllable union set (CUS) analysis and controllable intersection set (CIS) analysis. Definitions of CUS and CIS are demonstrated and computational method of them based on Gauss pseudospectral method is presented. Their applications on entry states distribution analysis under uncertainties and robustness of nominal entry state selection to uncertainties are illustrated by situations with ballistic coefficient, lift-to-drag ratio and atmospheric uncertainty in Mars entry. With analysis of CUS and CIS, the robustness of entry state selection and entry trajectory to model uncertainties can be guaranteed, thus enhancing the safety, reliability and accuracy under model uncertainties during planetary entry and landing.

  11. NLS base heating CFD analysis

    NASA Technical Reports Server (NTRS)

    Ascoli, Edward P.; Heiba, Adel H.; Hsu, Yann-Fu; Lagnado, Ronald R.; Lynch, Edward D.

    1993-01-01

    Concerns raised over possible base heating effects on the National Launch System (NLS) 1.5 stage reference vehicle resulted in the use of CFD as a predictive analysis tool. The objective established was to obtain good engineering solutions to describe the base region flowfields at 10,000 ft and 50,000 ft altitudes. The Rockwell USA CFD code was employed with a zero-equation turbulence model and a four species, 1 step chemical kinetics package. Three solutions were generated for the specified altitudes on coarse and fine grids. CFD results show the base region flowfields to be highly three dimensional in character. At the 10,000 ft altitude, plumes contract soon after exiting the nozzles and do not interact with each other. No mechanism was identified for driving hot gas back into the base region and no significant amounts of hydrogen or water were found in the base region. Consequently, surface temperatures were all near the ambient level. At 50,000 ft, the nozzle exhaust plumes begin to interact, particularly those of the two inboard engines which are closer together. A small amount of hot gas is recirculated between the inboard nozzles near the nozzle exit plane. As a result, base region surface temperatures are slightly elevated, but still remain well within the design guideline of 1000 R.

  12. NLS base heating CFD analysis

    NASA Astrophysics Data System (ADS)

    Ascoli, Edward P.; Heiba, Adel H.; Hsu, Yann-Fu; Lagnado, Ronald R.; Lynch, Edward D.

    1993-07-01

    Concerns raised over possible base heating effects on the National Launch System (NLS) 1.5 stage reference vehicle resulted in the use of CFD as a predictive analysis tool. The objective established was to obtain good engineering solutions to describe the base region flowfields at 10,000 ft and 50,000 ft altitudes. The Rockwell USA CFD code was employed with a zero-equation turbulence model and a four species, 1 step chemical kinetics package. Three solutions were generated for the specified altitudes on coarse and fine grids. CFD results show the base region flowfields to be highly three dimensional in character. At the 10,000 ft altitude, plumes contract soon after exiting the nozzles and do not interact with each other. No mechanism was identified for driving hot gas back into the base region and no significant amounts of hydrogen or water were found in the base region. Consequently, surface temperatures were all near the ambient level. At 50,000 ft, the nozzle exhaust plumes begin to interact, particularly those of the two inboard engines which are closer together. A small amount of hot gas is recirculated between the inboard nozzles near the nozzle exit plane. As a result, base region surface temperatures are slightly elevated, but still remain well within the design guideline of 1000 R.

  13. Analysis and control of distributed cooperative systems.

    SciTech Connect

    Feddema, John Todd; Parker, Eric Paul; Wagner, John S.; Schoenwald, David Alan

    2004-09-01

    As part of DARPA Information Processing Technology Office (IPTO) Software for Distributed Robotics (SDR) Program, Sandia National Laboratories has developed analysis and control software for coordinating tens to thousands of autonomous cooperative robotic agents (primarily unmanned ground vehicles) performing military operations such as reconnaissance, surveillance and target acquisition; countermine and explosive ordnance disposal; force protection and physical security; and logistics support. Due to the nature of these applications, the control techniques must be distributed, and they must not rely on high bandwidth communication between agents. At the same time, a single soldier must easily direct these large-scale systems. Finally, the control techniques must be provably convergent so as not to cause undo harm to civilians. In this project, provably convergent, moderate communication bandwidth, distributed control algorithms have been developed that can be regulated by a single soldier. We have simulated in great detail the control of low numbers of vehicles (up to 20) navigating throughout a building, and we have simulated in lesser detail the control of larger numbers of vehicles (up to 1000) trying to locate several targets in a large outdoor facility. Finally, we have experimentally validated the resulting control algorithms on smaller numbers of autonomous vehicles.

  14. Use-Misuse Case Driven Analysis of Positive Train Control

    NASA Astrophysics Data System (ADS)

    Hartong, Mark; Goel, Rajni; Wijesekera, Duminda

    Forensic analysis helps identify the causes of crimes and accidents. Determination of cause, however, requires detailed knowledge of a system's design and operational characteristics. This paper advocates that "use cases," which specify operational interactions and requirements, and "misuse cases," which specify potential misuse or abuse scenarios, can be used to analyze and link forensic evidence and create postincident reconstructions. Use-misuse case analysis techniques involving non-probabilistic and probabilistic methods are described and applied to Positive Train Control (PTC) Systems — a network-based automated system that controls the movements of passenger and freight trains.

  15. Quantitative resilience analysis through control design.

    SciTech Connect

    Sunderland, Daniel; Vugrin, Eric D.; Camphouse, Russell Chris

    2009-09-01

    Critical infrastructure resilience has become a national priority for the U. S. Department of Homeland Security. System resilience has been studied for several decades in many different disciplines, but no standards or unifying methods exist for critical infrastructure resilience analysis. Few quantitative resilience methods exist, and those existing approaches tend to be rather simplistic and, hence, not capable of sufficiently assessing all aspects of critical infrastructure resilience. This report documents the results of a late-start Laboratory Directed Research and Development (LDRD) project that investigated the development of quantitative resilience through application of control design methods. Specifically, we conducted a survey of infrastructure models to assess what types of control design might be applicable for critical infrastructure resilience assessment. As a result of this survey, we developed a decision process that directs the resilience analyst to the control method that is most likely applicable to the system under consideration. Furthermore, we developed optimal control strategies for two sets of representative infrastructure systems to demonstrate how control methods could be used to assess the resilience of the systems to catastrophic disruptions. We present recommendations for future work to continue the development of quantitative resilience analysis methods.

  16. REACTOR ANALYSIS AND VIRTUAL CONTROL ENVIRONMENT (RAVEN) FY12 REPORT

    SciTech Connect

    Cristian Rabiti; Andrea Alfonsi; Joshua Cogliati; Diego Mandelli; Robert Kinoshita

    2012-09-01

    RAVEN is a complex software tool that will have tasks spanning from being the RELAP-7 user interface, to using RELAP-7 to perform Risk Informed Safety Characterization (RISMC), and to controlling RELAP-7 calculation execution. The goal of this document is to: 1. Highlight the functional requirements of the different tasks of RAVEN 2. Identify shared functions that could be aggregate in modules so to obtain a minimal software redundancy and maximize software utilization. RAVEN is in fact a software framework that will allow exploiting the following functionalities: • Derive and actuate the control logic required to: o Simulate the plant control system o Simulate the operator (procedure guided) actions o Perform Monte Carlo sampling of random distributed events o Perform event three based analysis • Provide a GUI to: o Input a plant description to RELAP-7 (component, control variable, control parameters) o Concurrent monitoring of Control Parameters o Concurrent alteration of control parameters • Provide Post Processing data mining capability based on o Dimensionality reduction o Cardinality reduction In this document it will be shown how an appropriate mathematical formulation of the control logic and probabilistic analysis leads to have most of the software infrastructure leveraged between the two main tasks. Further, this document will go through the development accomplished this year, including simulation results, and priorities for the next years development

  17. Network-based production quality control

    NASA Astrophysics Data System (ADS)

    Kwon, Yongjin; Tseng, Bill; Chiou, Richard

    2007-09-01

    This study investigates the feasibility of remote quality control using a host of advanced automation equipment with Internet accessibility. Recent emphasis on product quality and reduction of waste stems from the dynamic, globalized and customer-driven market, which brings opportunities and threats to companies, depending on the response speed and production strategies. The current trends in industry also include a wide spread of distributed manufacturing systems, where design, production, and management facilities are geographically dispersed. This situation mandates not only the accessibility to remotely located production equipment for monitoring and control, but efficient means of responding to changing environment to counter process variations and diverse customer demands. To compete under such an environment, companies are striving to achieve 100%, sensor-based, automated inspection for zero-defect manufacturing. In this study, the Internet-based quality control scheme is referred to as "E-Quality for Manufacturing" or "EQM" for short. By its definition, EQM refers to a holistic approach to design and to embed efficient quality control functions in the context of network integrated manufacturing systems. Such system let designers located far away from the production facility to monitor, control and adjust the quality inspection processes as production design evolves.

  18. Control system design and analysis using the INteractive Controls Analysis (INCA) program

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H.; Downing, John P.

    1987-01-01

    The INteractive Controls Analysis (INCA) program was developed at the Goddard Space Flight Center to provide a user friendly efficient environment for the design and analysis of linear control systems. Since its inception, INCA has found extensive use in the design, development, and analysis of control systems for spacecraft, instruments, robotics, and pointing systems. Moreover, the results of the analytic tools imbedded in INCA have been flight proven with at least three currently orbiting spacecraft. This paper describes the INCA program and illustrates, using a flight proven example, how the package can perform complex design analyses with relative ease.

  19. Control system design and analysis using the INteractive Controls Analysis (INCA) program

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H.; Downing, John P.

    1987-01-01

    The INteractive Controls Analysis (INCA) program was developed at the Goddard Space Flight Center to provide a user friendly efficient environment for the design and analysis of linear control systems. Since its inception, INCA has found extensive use in the design, development, and analysis of control systems for spacecraft, instruments, robotics, and pointing systems. Moreover, the results of the analytic tools imbedded in INCA have been flight proven with at least three currently orbiting spacecraft. This paper describes the INCA program and illustrates, using a flight proven example, how the package can perform complex design analyses with relative ease.

  20. Integrated communication and control systems. I - Analysis

    NASA Technical Reports Server (NTRS)

    Halevi, Yoram; Ray, Asok

    1988-01-01

    The paper presents the results of an ICCS analysis focusing on discrete-time control systems subject to time-varying delays. The present analytical technique is applicable to integrated dynamic systems such as those encountered in advanced aircraft, spacecraft, and the real-time control of robots and machine tools via a high-speed network within an autonomous manufacturing environment. The significance of data latency and missynchronization between individual system components in ICCS networks is discussed in view of the time-varying delays.

  1. Can Aidi injection restore cellular immunity and improve clinical efficacy in non-small-cell lung cancer patients treated with platinum-based chemotherapy? A meta-analysis of 17 randomized controlled trials following the PRISMA guidelines.

    PubMed

    Xiao, Zheng; Wang, Chengqiong; Sun, Yongping; Li, Nana; Li, Jing; Chen, Ling; Yao, Xingsheng; Ding, Jie; Ma, Hu

    2016-11-01

    Aidi injection is an adjuvant chemotherapy drug commonly used in China. Can Aidi injection restore the cellular immunity and improve the clinical efficacy in non-small-cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy? There is a lack of strong evidence to prove it. To further reveal it, we systematically evaluated all related studies. We collected all studies about the clinical efficacy and cellular immunity of Aidi injection plus platinum-based chemotherapy for NSCLC in Medline, Embase, Web of Science, China national knowledge infrastructure database (CNKI), Chinese Scientific Journals Full-Text Database (VIP), Wanfang, China biological medicine database (CBM) (established to June 2015), Cochrane Central Register of Controlled Trials (CCRCT) (June 2015), Chinese clinical trial registry, and US-clinical trials (June 2015). We evaluated their quality according to the Cochrane evaluation handbook of randomized controlled trials (RCTs) (5.1.0), extracted data following the patient intervention control group outcomes principles and synthesized the data by meta-analysis. Seventeen (RCTs) with 1390 NSCLC patients were included, with general methodological quality in most trials. The merged relative risk (RR) values and their 95% CI of meta-analysis for objective response rate (ORR) and disease control rate (DCR) were as follows: 1.26 (1.12, 1.42) and 1.11(1.04, 1.17). The merged standardized mean difference (SMD) values and their 95% CI of meta-analysis for the percentage of CD3T cells, CD4T cells, CD8T cells, natural killer (NK) cells, and CD4/CD8 T cell ratio were as follows: 1.41, (0.89, 1.92), 1.59, (1.07, 2.11), 0.85, (0.38, 1.33), 1.64 (0.89, 2.39) and 0.91, (0.58, 1.24). Compared with platinum-based chemotherapy alone, all differences were statistically significant. These results might be overestimated or underestimated. Aidi injection plus platinum-based chemotherapy can improve the clinical efficacy of patients with NSCLC. Aidi

  2. Asthma control in patients treated with inhaled corticosteroids and long-acting beta agonists: A population-based analysis in Germany.

    PubMed

    Kondla, Anke; Glaab, Thomas; Pedersini, Riccardo; Lommatzsch, Marek

    2016-09-01

    The prevalence and the characteristics of poor asthma control among adults treated with combinations of inhaled corticosteroids (ICS) and long-acting beta-agonists (LABA) are not completely understood. Data from adult patients in Germany with self-reported asthma treated with an ICS-LABA combination in the National Health and Wellness Survey (NHWS) were analysed. Patients with well-controlled and not well-controlled asthma according to the Asthma Control Test (ACT) score were compared, with respect to socio-demographic characteristics, attitudes, adherence and outcomes. Among the German patients with self-reported asthma (5.2% of the respondents), 16.2% (382 patients) were treated with an ICS-LABA combination and did not report concomitant chronic obstructive pulmonary disease, chronic bronchitis or emphysema. In this subgroup, 55.8% had not well-controlled asthma (ACT < 20). ICS-LABA treated patients with not well-controlled asthma were more likely to report emergency visits (16.4% vs. 8.9%), missed more time from work (absenteeism: 12.9% vs. 4.3%), were more impaired while at work (presenteeism: 29.0% vs. 14.9%) and were more likely to be women (69.0% vs. 57.4%), compared with well-controlled patients. There were no significant differences in age, body mass index, smoking, income, education or self-reported adherence between the two groups, but different attitudes regarding the patient-physician relationship. A substantial proportion of patients treated with ICS and LABA had not well-controlled asthma. These patients did not differ from well-controlled patients in terms of education or self-reported adherence, but in terms of their attitudes regarding the patient-physician relationship. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Flexible control techniques for a lunar base

    NASA Technical Reports Server (NTRS)

    Kraus, Thomas W.

    1992-01-01

    applications with little or no customization. This means that lunar process control projects will not be delayed by unforeseen problems or last minute process modifications. The software will include all of the tools needed to adapt to virtually any changes. In contrast to other space programs which required the development of tremendous amounts of custom software, lunar-based processing facilities will benefit from the use of existing software technology which is being proven in commercial applications on Earth.

  4. Adaptive control for solar energy based DC microgrid system development

    NASA Astrophysics Data System (ADS)

    Zhang, Qinhao

    During the upgrading of current electric power grid, it is expected to develop smarter, more robust and more reliable power systems integrated with distributed generations. To realize these objectives, traditional control techniques are no longer effective in either stabilizing systems or delivering optimal and robust performances. Therefore, development of advanced control methods has received increasing attention in power engineering. This work addresses two specific problems in the control of solar panel based microgrid systems. First, a new control scheme is proposed for the microgrid systems to achieve optimal energy conversion ratio in the solar panels. The control system can optimize the efficiency of the maximum power point tracking (MPPT) algorithm by implementing two layers of adaptive control. Such a hierarchical control architecture has greatly improved the system performance, which is validated through both mathematical analysis and computer simulation. Second, in the development of the microgrid transmission system, the issues related to the tele-communication delay and constant power load (CPL)'s negative incremental impedance are investigated. A reference model based method is proposed for pole and zero placements that address the challenges of the time delay and CPL in closed-loop control. The effectiveness of the proposed modeling and control design methods are demonstrated in a simulation testbed. Practical aspects of the proposed methods for general microgrid systems are also discussed.

  5. Airphoto analysis of erosion control practices

    NASA Technical Reports Server (NTRS)

    Morgan, K. M.; Morris-Jones, D. R.; Lee, G. B.; Kiefer, R. W.

    1980-01-01

    The Universal Soil Loss Equation (USLE) is a widely accepted tool for erosion prediction and conservation planning. In this study, airphoto analysis of color and color infrared 70 mm photography at a scale of 1:60,000 was used to determine the erosion control practice factor in the USLE. Information about contour tillage, contour strip cropping, and grass waterways was obtained from aerial photography for Pheasant Branch Creek watershed in Dane County, Wisconsin.

  6. Application of loop analysis for evaluation of malaria control interventions

    PubMed Central

    2014-01-01

    Background Despite continuous efforts and recent rapid expansion in the financing and implementation of malaria control interventions, malaria still remains one of the most devastating global health issues. Even in countries that have been successful in reducing the incidence of malaria, malaria control is becoming more challenging because of the changing epidemiology of malaria and waning community participation in control interventions. In order to improve the effectiveness of interventions and to promote community understanding of the necessity of continued control efforts, there is an urgent need to develop new methodologies that examine the mechanisms by which community-based malaria interventions could reduce local malaria incidence. Methods This study demonstrated how the impact of community-based malaria control interventions on malaria incidence can be examined in complex systems by qualitative analysis combined with an extensive review of literature. First, sign digraphs were developed through loop analysis to analyse seven interventions: source reduction, insecticide/larvicide use, biological control, treatment with anti-malarials, insecticide-treated mosquito net/long-lasting insecticidal net, non-chemical personal protection measures, and educational intervention. Then, for each intervention, the sign digraphs and literature review were combined to analyse a variety of pathways through which the intervention can influence local malaria incidence as well as interactions between variables involved in the system. Through loop analysis it is possible to see whether increases in one variable qualitatively increases or decreases other variables or leaves them unchanged and the net effect of multiple, interacting variables. Results Qualitative analysis, specifically loop analysis, can be a useful tool to examine the impact of community-based malaria control interventions. Without relying on numerical data, the analysis was able to describe pathways through

  7. Parameter Transient Behavior Analysis on Fault Tolerant Control System

    NASA Technical Reports Server (NTRS)

    Belcastro, Christine (Technical Monitor); Shin, Jong-Yeob

    2003-01-01

    In a fault tolerant control (FTC) system, a parameter varying FTC law is reconfigured based on fault parameters estimated by fault detection and isolation (FDI) modules. FDI modules require some time to detect fault occurrences in aero-vehicle dynamics. This paper illustrates analysis of a FTC system based on estimated fault parameter transient behavior which may include false fault detections during a short time interval. Using Lyapunov function analysis, the upper bound of an induced-L2 norm of the FTC system performance is calculated as a function of a fault detection time and the exponential decay rate of the Lyapunov function.

  8. Model-Based Wavefront Control for CCAT

    NASA Technical Reports Server (NTRS)

    Redding, David; Lou, John Z.; Kissil, Andy; Bradford, Matt; Padin, Steve; Woody, David

    2011-01-01

    The 25-m aperture CCAT submillimeter-wave telescope will have a primary mirror that is divided into 162 individual segments, each of which is provided with 3 positioning actuators. CCAT will be equipped with innovative Imaging Displacement Sensors (IDS) inexpensive optical edge sensors capable of accurately measuring all segment relative motions. These measurements are used in a Kalman-filter-based Optical State Estimator to estimate wavefront errors, permitting use of a minimum-wavefront controller without direct wavefront measurement. This controller corrects the optical impact of errors in 6 degrees of freedom per segment, including lateral translations of the segments, using only the 3 actuated degrees of freedom per segment. The global motions of the Primary and Secondary Mirrors are not measured by the edge sensors. These are controlled using a gravity-sag look-up table. Predicted performance is illustrated by simulated response to errors such as gravity sag.

  9. Memory-based parallel data output controller

    NASA Technical Reports Server (NTRS)

    Stattel, R. J.; Niswander, J. K. (Inventor)

    1984-01-01

    A memory-based parallel data output controller employs associative memories and memory mapping to decommutate multiple channels of telemetry data. The output controller contains a random access memory (RAM) which has at least as many address locations as there are channels. A word counter addresses the RAM which provides as it outputs an encoded peripheral device number and a MSB/LSB-first flag. The encoded device number and a bit counter address a second RAM which contains START and STOP flags to pick out the required bits from the specified word number. The LSB/MSB, START and STOP flags, along with the serial input digital data go to a control block which selectively fills a shift register used to drive the parallel data output bus.

  10. Analysis of routine pilot-controller communication

    NASA Technical Reports Server (NTRS)

    Morrow, Daniel G.; Lee, Alfred; Rodvold, Michelle

    1990-01-01

    Although pilot-controller communication is central to aviation safety, this area of aviation human factors has not been extensively researched. Most research has focused on what kinds of communication problems occur. A more complete picture of communication problems requires understanding how communication usually works in routine operations. A sample of routine pilot-controller communication in the TRACON environment is described. After describing several dimensions of routine communication, three kinds of communication problems are treated: inaccuracies such as incorrect readbacks, procedural deviations such as missing callsigns and readbacks, and nonroutine transactions where pilot and controller must deal with misunderstandings or other communication problems. Preliminary results suggest these problems are not frequent events in daily operations. However, analysis of the problems that do occur suggest some factors that may cause them.

  11. Analysis of routine pilot-controller communication

    NASA Technical Reports Server (NTRS)

    Morrow, Daniel G.; Lee, Alfred; Rodvold, Michelle

    1990-01-01

    Although pilot-controller communication is central to aviation safety, this area of aviation human factors has not been extensively researched. Most research has focused on what kinds of communication problems occur. A more complete picture of communication problems requires understanding how communication usually works in routine operations. A sample of routine pilot-controller communication in the TRACON environment is described. After describing several dimensions of routine communication, three kinds of communication problems are treated: inaccuracies such as incorrect readbacks, procedural deviations such as missing callsigns and readbacks, and nonroutine transactions where pilot and controller must deal with misunderstandings or other communication problems. Preliminary results suggest these problems are not frequent events in daily operations. However, analysis of the problems that do occur suggest some factors that may cause them.

  12. Control Analysis of flexible Solar Sails

    NASA Technical Reports Server (NTRS)

    Thomas, Stephanie J.; Paluszek, Michael A.

    2005-01-01

    Future solar sail missions will require sails with dimensions on the order of 100 m to l km. At these sizes, given the gossamer nature of the sail supporting structures, flexible modes may be low enough to interact with the control system. This paper develops a practical analysis of the flexible interactions using state-space systems and modal data from standard finite element models of the sail sub- system. The modal data is combined with a rigid core bus to create a modal coordinate state-space plant, which can be analyzed for stability with a state-space controller. Results are presented for an 80 m sail for both collocated actuation and control by actuators mounted at the sail tips.

  13. Sensor-based demand controlled ventilation

    SciTech Connect

    De Almeida, A.T.; Fisk, W.J.

    1997-07-01

    In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

  14. Meta-Analysis of Multiple Simulation-Based Experiments

    DTIC Science & Technology

    2013-06-01

    and Developing Hypotheses 6 Waterfall approach 1: Establishing the objectives of the meta - analysis and identifying the specific hypotheses that...Operational Environments” Paper ID: 48 Meta - Analysis of Multiple Simulation-Based Experiments Topics: Topic 5: Experimentation, Metrics, and...circumstances. Thus, effectively utilizing a variety of models in a prospective meta - analysis (a set of common hypotheses and controllable variables

  15. Analysis of national water-pollution-control policies. 2. Agricultural sediment control

    SciTech Connect

    Gianessi, L.P.; Peskin, H.M.

    1981-08-01

    A national water network model is used to analyze the likely effects of agricultural sediment-control policies on the quality of the nation's waters. This analysis is believed superior to previous assessments based mainly on erosion estimates without accounting for the characteristics of the receiving water or the contribution of pollutants from nonagricultural activities. Specifically, while the earlier assessments concluded that agriculture-related pollution problems are widespread and ubiquitous, this analysis concludes that it is probably more efficient to focus sediment-related pollution-control policies on about one third of the nation's agricultural regions. 30 references, 5 figures, 11 tables.

  16. Remote engineering for a cheese whey biorefinery: an Internet-based application for process design, economic analysis, monitoring, and control of multiple plant sites.

    PubMed

    Pinto, Gilson A; Giordano, Raquel L C; Giordano, Roberto C

    2009-01-01

    The proteolysis of cheese whey with the aid of immobilized enzymes is an attractive alternative for this by-product of the dairy industry. Among some possible applications for whey protein hydrolysates, one may cite their use as protein source for individuals with reduced capacity of digestion, or with genetic metabolic disorders (phenylketonuria patients, for instance). The multipurpose plant that processes whey is named here as a cheese whey biorefinery. This work presents the remote control and monitoring of the whey biorefineries using the Internet. In an integrated environment, the web application also enables simulation and economic analyses of the process. This technology might allow small companies to access a remote "engineering centre", with know-how on plant design and advanced control techniques. The idea can also be extended to large dairy companies, providing the remote control of geographically spread sites of production.

  17. Piloted simulation of a ground-based time-control concept for air traffic control

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Green, Steven M.

    1989-01-01

    A joint simulation was carried out using a piloted simulator and an advanced-concept air traffic control simulation to study the acceptability and accuracy of the ground-based four-dimensional descent advisor (DA), an automation aid based on accurate models of aircraft performance and weather conditions. In the piloted simulation, airline crews executed controller-issued descent advisories along standard curved-path arrival routes and were able to achieve an arrival-time precision of plus or minus 20 s at the metering fix. An analysis of errors generated in turns resulted in a further enhancement of the DA algorithm.

  18. Design and Analysis of Morpheus Lander Flight Control System

    NASA Technical Reports Server (NTRS)

    Jang, Jiann-Woei; Yang, Lee; Fritz, Mathew; Nguyen, Louis H.; Johnson, Wyatt R.; Hart, Jeremy J.

    2014-01-01

    The Morpheus Lander is a vertical takeoff and landing test bed vehicle developed to demonstrate the system performance of the Guidance, Navigation and Control (GN&C) system capability for the integrated autonomous landing and hazard avoidance system hardware and software. The Morpheus flight control system design must be robust to various mission profiles. This paper presents a design methodology for employing numerical optimization to develop the Morpheus flight control system. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics and propellant slosh. Under the assumption that the Morpheus time-varying dynamics and control system can be frozen over a short period of time, the flight controllers are designed to stabilize all selected frozen-time control systems in the presence of parametric uncertainty. Both control gains in the inner attitude control loop and guidance gains in the outer position control loop are designed to maximize the vehicle performance while ensuring robustness. The flight control system designs provided herein have been demonstrated to provide stable control systems in both Draper Ares Stability Analysis Tool (ASAT) and the NASA/JSC Trick-based Morpheus time domain simulation.

  19. Liquid chromatographic method for analysis of All-rac-alpha-tocopheryl acetate and retinyl palmitate in soy-based infant formula using a zero-control reference material (ZRM) as a method development tool.

    PubMed

    Chase, G W; Long, A R; Eitenmiller, R R

    1998-01-01

    A liquid chromatographic method is described for analysis of all-rac-alpha-tocopheryl acetate, tocopherols, and retinyl palmitate in soy-based infant formula. The vitamins are extracted in isopropyl alcohol and hexane--ethyl acetate without saponification and quantitated by normal-phase chromatography with fluorescence detection. All-rac-alpha-tocopheryl acetate and retinyl palmitate are quantitated isocratically with mobile phases of 0.5% (v/v) and 0.125% (v/v) isopropyl alcohol in hexane, respectively. Recoveries from zero control reference material soy-based formula averaged 97.2% (n = 25) for retinyl palmitate and 100% (n = 25) for all-rac-alpha-tocopheryl acetate. Coefficients of variation ranged from 1.21 to 2.86% for retinyl palmitate and from 1.49 to 5.16% for all-rac-alpha-tocopheryl acetate. The method provides a rapid, specific, and easily controlled assay for analysis of vitamin A and vitamin E in fortified infant formula. Additionally, the method eliminates use of chlorinated solvents.

  20. A meta-analysis of long follow-up outcomes of laparoscopic Nissen (total) versus Toupet (270°) fundoplication for gastro-esophageal reflux disease based on randomized controlled trials in adults.

    PubMed

    Du, Xing; Hu, Zhiwei; Yan, Chao; Zhang, Chao; Wang, Zhonggao; Wu, Jimin

    2016-08-02

    Laparoscopic Nissen fundoplication (LNF) is the most common surgical procedure for the surgical management of gastro-esophageal reflux disease (GERD). Laparoscopic Toupet fundoplication (LTF) has been reported to have a lower prevalence of postoperative complications yet still obtain a similar level of reflux control. We conducted a meta-analysis to confirm the value of LNF and LTF. PubMed, Medline, Embase, Cochrane Library and Springerlink were searched for randomized controlled trials (RCTs) comparing LNF and LTF. Data regarding the benefits and adverse results of two techniques were extracted and compared using a meta-analysis. Eight eligible RCTs comparing LNF (n = 625) and LTF (n = 567) were identified. There were no significant differences between LNF and LTF with regard to hospitalization duration, perioperative complications, patient satisfaction, postoperative heartburn, regurgitation, postoperative DeMeester scores, or esophagites. A shorter operative time and higher postoperative lower esophageal sphincter pressure were associated with LNF. Prevalence of postoperative dysphagia, gas-bloating, inability to belch, dilatation for dysphagia and reoperation were higher after LNF, but subgroup analyses showed that differences with respect to dysphagia between LNF and LTF disappeared over time. Subgroup analyses did not support "tailored therapy" according to preoperative esophageal motility. LNF and LTF have equivalently good control of GERD and result in a similar prevalence of patient satisfaction. Based on current evidence, it is not rational or advisable to abandon LNF when choosing a surgical procedure for GERD.

  1. Quantum memory based on phase matching control

    NASA Astrophysics Data System (ADS)

    Zhang, Xi-Wen; Kalachev, A.; Hemmer, P.; Scully, M. O.; Kocharovskaya, O.

    2014-09-01

    We discuss a class of quantum memory (QM) scheme based on phase matching control (PMC). A single-photon wave packet can be mapped into and retrieved on demand from a long-lived spin grating in the presence of a control field, forming along with the signal field a Raman configuration, when the wave vector of the control field is continuously changed in time. Such mapping and retrieval takes place due to the phase matching condition and requires neither a variation of the amplitude of the control field nor inhomogeneous broadening of the medium. We discuss the general model of PMC QM and its specific implementation via (i) modulation of the refractive index, (ii) angular scanning of the control field, and (iii) its frequency chirp. We show that the performance of the PMC QM protocol may be as good as those realized in the gradient echo memory (GEM) but achieved with less stringent requirements on the medium. We suggest the experimental realization of PMC QM in nitrogen vacancies (NV) and silicon vacancies (SiV) in diamond as well as in rare-earth doped crystals. We dedicate this paper to the memory of Professor Igor Yevseyev, the internationally renowned scientist, one of the pioneers of the field of quantum coherence effects. We have warm memories of many fruitful and pleasant communications with Professor Yevseyev during the International Laser Physics Workshops, which he so successfully organized and hosted.

  2. Composable communication constraint-based control

    NASA Astrophysics Data System (ADS)

    Hsieh, Mong-ying A.; Srivastava, Pranav; Kumar, Vijay; Taylor, Camillo J.

    2004-12-01

    We describe a framework for multi-vehicle control which explicitly incorporates the state of the communication network and the constraints imposed by specifications on the quality of the communications links available to each robot. In a multi-robot adhoc setting, the need for guaranteed communications is essential for cooperative behavior. We propose a control methodology that ensures local connectivity in multi-robot navigation. Specifically, given an initial and final configuration of robots in which the quality of each communication link is above some specified threshold, we synthesize controllers that guarantee each robot goes to its goal destination while maintaining the quality of the communication links above the given threshold. For the sake of simplicity, we assume each robot has a pre-assigned "base unit" with which the robot tries to maintain connectivity while performing the assigned task. The proposed control methodology allows the robot's velocity to align with the tangent of a critical communication surface such that it might be possible for the robot to move on the surface. No assumptions are made regarding the critical surface, which might be arbitrarily complex for cluttered urban environments. The stability of such technique is shown and three-dimensional simulations with a small team of robots are presented. The paper demonstrates the performance of the control scheme in various three-dimensional settings with proofs of guarantees in simple scenarios.

  3. Moderate temperature control technology for a lunar base

    NASA Technical Reports Server (NTRS)

    Swanson, Theodore D.; Sridhar, K. R.; Gottmann, Matthias

    1993-01-01

    A parametric analysis is performed to compare different heat pump based thermal control systems for a Lunar Base. Rankine cycle and absorption cycle heat pumps are compared and optimized for a 100 kW cooling load. Variables include the use or lack of an interface heat exchanger, and different operating fluids. Optimization of system mass to radiator rejection temperature is performed. The results indicate a relatively small sensitivity of Rankine cycle system mass to these variables, with optimized system masses of about 6000 kg for the 100 kW thermal load. It is quantitaively demonstrated that absorption based systems are not mass competitive with Rankine systems.

  4. Relation chain based clustering analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Cheng-ning; Zhao, Ming-yang; Luo, Hai-bo

    2011-08-01

    Clustering analysis is currently one of well-developed branches in data mining technology which is supposed to find the hidden structures in the multidimensional space called feature or pattern space. A datum in the space usually possesses a vector form and the elements in the vector represent several specifically selected features. These features are often of efficiency to the problem oriented. Generally, clustering analysis goes into two divisions: one is based on the agglomerative clustering method, and the other one is based on divisive clustering method. T