Science.gov

Sample records for analysis based control

  1. 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. PMID:24314832

  2. Bifurcation analysis of a Lyapunov-based controlled boost converter

    NASA Astrophysics Data System (ADS)

    Spinetti-Rivera, Mario; Olm, Josep M.; Biel, Domingo; Fossas, Enric

    2013-11-01

    Lyapunov-based controlled boost converters have a unique equilibrium point, which is globally asymptotically stable, for known resistive loads. This article investigates the dynamic behaviors that appear in the system when the nominal load differs from the actual one and no action is taken by the controller to compensate for the mismatch. Exploiting the fact that the closed-loop system is, in fact, planar and quadratic, one may provide not only local but also global stability results: specifically, it is proved that the number of equilibria of the converter may grow up to three and that, in any case, the system trajectories are always bounded, i.e. it is a bounded quadratic system. The possible phase portraits of the closed-loop system are also characterized in terms of the selected bifurcation parameters, namely, the actual load value and the gain of the control law. Accordingly, the analysis allows the numerical illustration of many bifurcation phenomena that appear in bounded quadratic systems through a physical example borrowed from power electronics.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Model-based analysis of context-specific cognitive control.

    PubMed

    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

  10. 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.

  11. 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.

  12. 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.

  13. A model-based control protocol for transition from ICU to HDU: Robustness analysis.

    PubMed

    Razak, Normy N; Chase, J Geoffrey; Suhaimi, Fatanah M; Shaw, Geoffrey M; Jamaluddin, Ummu

    2013-01-01

    The robustness of a model-based control protocol as a less intensive TGC protocol using insulin Glargine for provision of basal insulin is simulated in this study. To quantify the performance and robustness of the protocol to errors, namely physiological variability and sensor errors, an in-silico Monte Carlo analysis is performed. Actual patient data from Christchurch Hospital, New Zealand were used as virtual trial patients. PMID:24109660

  14. A Simulation-Based Comparison of Covariate Adjustment Methods for the Analysis of Randomized Controlled Trials

    PubMed Central

    Chaussé, Pierre; Liu, Jin; Luta, George

    2016-01-01

    Covariate adjustment methods are frequently used when baseline covariate information is available for randomized controlled trials. Using a simulation study, we compared the analysis of covariance (ANCOVA) with three nonparametric covariate adjustment methods with respect to point and interval estimation for the difference between means. The three alternative methods were based on important members of the generalized empirical likelihood (GEL) family, specifically on the empirical likelihood (EL) method, the exponential tilting (ET) method, and the continuous updated estimator (CUE) method. Two criteria were considered for the comparison of the four statistical methods: the root mean squared error and the empirical coverage of the nominal 95% confidence intervals for the difference between means. Based on the results of the simulation study, for sensitivity analysis purposes, we recommend the use of ANCOVA (with robust standard errors when heteroscedasticity is present) together with the CUE-based covariate adjustment method. PMID:27077870

  15. 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. PMID:26655959

  16. 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

  17. Control theoretical analysis of a window-based flow control mechanism for TCP connections with different propagation delays

    NASA Astrophysics Data System (ADS)

    Ohsaki, Hiroyuki; Takagaki, Keiichi; Murata, Masayuki

    2001-07-01

    A feedback-based congestion control mechanism is essential to realize an efficient best-effort service in high-speed networks. A window-based flow control mechanism called TCP (Transmission Control Protocol), which a sort of feedback-based congestion control mechanism, has been widely used in the current Internet. Recently-proposed TCP Vegas is another version of TCP mechanism, and can achieve better performance than the current TCP Reno. In our previous works, we have analyzed stability of a window-based flow control mechanism based on TCP Vegas in both homogeneous and heterogeneous networks. In this paper, using our analytic results, we invesitigate how the dynamics of the window-based flow control mechanism based on TCP Vegas is affected by the difference in propagation delays of TCP connections. We also investigate the effect of various system parameters on transient performance of the window-based flow control mechanism.

  18. Preliminary analysis of a membrane-based atmosphere-control subsystem

    NASA Technical Reports Server (NTRS)

    Mccray, Scott B.; Newbold, David D.; Ray, Rod; Ogle, Kathryn

    1993-01-01

    Controlled ecological life supprot systems will require subsystems for maintaining the consentrations of atmospheric gases within acceptable ranges in human habitat chambers and plant growth chambers. The goal of this work was to develop a membrane-based atmosphere comntrol (MBAC) subsystem that allows the controlled exchange of atmospheric componets (e.g., oxygen, carbon dioxide, and water vapor) between these chambers. The MBAC subsystem promises to offer a simple, nonenergy intensive method to separate, store and exchange atmospheric components, producing optimal concentrations of components in each chamber. In this paper, the results of a preliminary analysis of the MBAC subsystem for control of oxygen and nitrogen are presented. Additionally, the MBAC subsystem and its operation are described.

  19. 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

  20. 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

  1. [Analysis suspected allergic factors to shenqi fuzheng injection based on prescription sequence analysis and nested case control study].

    PubMed

    Ai, Qing-Hua; Zeng, Xian-Bin; Xie, Yan-Ming; Yang, Wei

    2014-09-01

    This study based on twenty 3A grade hospital information system (HIS) database in China, adopt toprescription sequence analysis (PSA) with nested case control study (NCCS) to analysis mainly suspected allergy factor of Shenqi Fuzheng injection (Shenqi Fuzheng). Study design according to start to stop using Shenqi Fuzheng whether using dexamethasone injection will crowd divided into cases group and control group, each case matched 4 controls were selected, two groups according to the ratio of the age and sex matched well. Square test, Fisher exact test, single factor and multiple factor logistic regression were used to analyze data Condition on admission, allergic history, dosage and drug combinations were taken into account in cases of suspected allergic reactions. After analysis in two subgroups we found that the single dose (P = 0.000 2) and the combined use of matrine (P < 0.000 1, OR = 14.312, confidence interval [8.184, 25.029]) had significant effects on the suspected allergic reaction. Study on the existing HIS data and the study method based on screening suspected risk factors for allergic reaction. This study can provide guidance for Shenqi Fuzheng injection safety using in clinical practice, and it can also provides new method for the clinical safety reevaluation of post-marketing Chinese medicine injection. PMID:25532396

  2. School food safety program based on hazard analysis and critical control point principles. Final rule.

    PubMed

    2009-12-15

    This final rule implements a legislative provision which requires school food authorities participating in the National School Lunch Program (NSLP) or the School Breakfast Program (SBP) to develop a school food safety program for the preparation and service of school meals served to children. The school food safety program must be based on the hazard analysis and critical control point (HACCP) system established by the Secretary of Agriculture. The food safety program will enable schools to take systematic action to prevent or minimize the risk of foodborne illness among children participating in the NSLP and SBP. PMID:20169679

  3. Analysis and amendment of flow control credit-based in SAN extension

    NASA Astrophysics Data System (ADS)

    Qin, Leihua; Yu, Shengsheng; Zhou, Jingli

    2005-11-01

    As organizations increasingly face an enormous influx of data that must be stored, protected, backed up and replicated. One of the best ways to achieve the goal is to interconnect geographically dispersed SANs through reliable and high-speed links. In this storage extension application, flow control deals with the problem where a device receives the frames faster than it can process them, when this happens, the result is that the device is forced to drop some of the frames. The FC flow control protocol is a credit-based mechanism and usually used for SAN extension over WDM and over SONET/SDH. With FC flow control, when a source storage device intends to send data to a target storage device, the initiating storage device must receive credits from target device. For every credit the initiating device obtains, it is permitted to transmit a FC frame, so congestion is always avoided in the network. This paper analysis the mechanisms of FC flow control and it's limitation in SAN extension when the extension distance increases. Computing result indicates that the maximum link efficiency and throughput in SAN extension have relation to credits, frame size and extension distance. In order to achieve the maximum link efficiency and throughput, an extended FC flow control mechanisms are proposed.

  4. Statin use and risk of glioma: population-based case-control analysis.

    PubMed

    Seliger, Corinna; Meier, Christoph Rudolf; Becker, Claudia; Jick, Susan Sara; Bogdahn, Ulrich; Hau, Peter; Leitzmann, Michael Fred

    2016-09-01

    Statins have been reported to decrease the incidence of cancer, but the risk of glioma among statin users has been investigated in only two prior observational studies, both of them suggesting a modest protective effect of statins. We conducted a matched case-control study using data from the UK-based Clinical Practice Research Datalink to analyse use of statins among 2469 cases with glioma and 24,690 controls. We performed conditional logistic regression analysis to calculate relative risks, estimated as odds ratios (ORs) with 95 % confidence intervals (CIs) adjusting for multiple confounding factors. As compared with non-use of statins, use of statins was not associated with risk of glioma (OR for ≥90 prescriptions=0.75; 95 % CI 0.48-1.17). Our findings do not support previous sparse evidence of a possible inverse association between statin use and glioma risk. PMID:27041698

  5. Cost-effectiveness of influenza control measures: a dynamic transmission model-based analysis.

    PubMed

    Chen, S-C; Liao, C-M

    2013-12-01

    We investigated the cost-effectiveness of different influenza control strategies in a school setting in Taiwan. A susceptible-exposure-infected-recovery (SEIR) model was used to simulate influenza transmission and we used a basic reproduction number (R 0)-asymptomatic proportion (θ) control scheme to develop a cost-effectiveness model. Based on our dynamic transmission model and economic evaluation, this study indicated that the optimal cost-effective strategy for all modelling scenarios was a combination of natural ventilation and respiratory masking. The estimated costs were US$10/year per person in winter for one kindergarten student. The cost for hand washing was estimated to be US$32/year per person, which was much lower than that of isolation (US$55/year per person) and vaccination (US$86/year per person) in containing seasonal influenza. Transmission model-based, cost-effectiveness analysis can be a useful tool for providing insight into the impacts of economic factors and health benefits on certain strategies for controlling seasonal influenza. PMID:23481024

  6. 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.

  7. 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

  8. Monitoring of an industrial process by multivariate control charts based on principal component analysis.

    PubMed

    Marengo, Emilio; Gennaro, Maria Carla; Gianotti, Valentina; Robotti, Elisa

    2003-01-01

    The control and monitoring of an industrial process is performed in this paper by the multivariate control charts. The process analysed consists of the bottling of the entire production of 1999 of the sparkling wine "Asti Spumante". This process is characterised by a great number of variables that can be treated with multivariate techniques. The monitoring of the process performed with classical Shewhart charts is very dangerous because they do not take into account the presence of functional relationships between the variables. The industrial process was firstly analysed by multivariate control charts based on Principal Component Analysis. This approach allowed the identification of problems in the process and of their causes. Successively, the SMART Charts (Simultaneous Scores Monitoring And Residual Tracking) were built in order to study the process in its whole. In spite of the successful identification of the presence of problems in the monitored process, the Smart chart did not allow an easy identification of the special causes of variation which casued the problems themselves. PMID:12911145

  9. Closed-loop transfer recovery with observer-based controllers. I - Analysis. II - Design

    NASA Technical Reports Server (NTRS)

    Chen, Ben M.; Saberi, Ali; Ly, Uy-Loi

    1992-01-01

    A detailed study is presented of three fundamental issues related to the problem of closed-loop transfer (CLT) recovery. The first issues concerns what can and cannot be achieved for a given system and for an arbitrary target CLT function (TCLTF). The second issue involves developing necessary and/or sufficient conditions for a TCLTF to be recoverable either exactly or approximately. The third issue involves the necessary and/or sufficient conditions on a given system such that it has at least one recoverable TCLTF. The results of the analysis identify some fundamental limitations of the given system as a consequence of its structural properties which enables designers to appreciate at the outset different design limitations incurred in the synthesis of output-feedback controllers. Then, the actual design of full-order or reduced-order observer-based controllers is addressed which will achieve as close as possibly the desired TCLTF. Three design methods are considered: (1) the ATEA method, (2) a method that minimizes the H2-norm of a recovery matrix, and (3) a method that minimizes the respective H(infinity) norm. The relative merits of the methods are discussed.

  10. 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. PMID:23331731

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

    PubMed

    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

  12. 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

  13. 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

  14. Model-based analysis of control/display interaction in the hover task

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.; Garg, Sanjay

    1987-01-01

    The effect of Control/Display interaction in the hover task is analyzed using an optimal control approach to modeling pilot control behavior. The control/display configurations considered are those previously evaluated in a flight research program. The experimental data-base is reviewed and the procedure for modeling the task and the displayed information is presented in detail. All model-based results, time-domain as well as frequency-domain, are found to correlate extremely well with the subjective pilot ratings and comments. Time-domain measures consist of root mean-square errors and control inputs, attention allocation to displayed quantities, and magnitudes of task objective function. Frequency-domain measures include bandwidth, stability margins, and pilot phase compensation. Results are also shown to agree with previous findings on task interference in multi-axis tasks.

  15. Pharmacogenetics-Based versus Conventional Dosing of Warfarin: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Shi, Changcheng; Yan, Wei; Wang, Gang; Wang, Fei; Li, Qingyu; Lin, Nengming

    2015-01-01

    Background Recently, using the patient’s genotype to guide warfarin dosing has gained interest; however, whether pharmacogenetics-based dosing (PD) improves clinical outcomes compared to conventional dosing (CD) remains unclear. Thus, we performed a meta-analysis to evaluate these two strategies. Methods The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese VIP and Chinese Wan-fang databases were searched. The Cochrane Collaboration’s tool was used to assess the risk of bias in randomized controlled trials (RCTs). The primary outcome was time within the therapeutic range (TTR); the secondary end points were the time to maintenance dose and time to first therapeutic international normalized ratio (INR), an INR greater than 4, adverse events, major bleeding, thromboembolism and death from any cause. Results A total of 11 trials involving 2,678 patients were included in our meta-analysis. The results showed that PD did not improve the TTR compared to CD, although PD significantly shortened the time to maintenance dose (MD = -8.80; 95% CI: -11.99 to -5.60; P<0.00001) and the time to first therapeutic INR (MD = -2.80; 95% CI: -3.45 to -2.15; P<0.00001). Additionally, PD significantly reduced the risk of adverse events (RR = 0.86; 95% CI: 0.75 to 0.99; P = 0.03) and major bleeding (RR = 0.36; 95% CI: 0.15 to 0.89, P = 0.03), although it did not reduce the percentage of INR greater than 4, the risk of thromboembolic events and death from any cause. Subgroup analysis showed that PD resulted in a better improvement in the endpoints of TTR and over-anticoagulation at a fixed initial dosage rather than a non-fixed initial dosage. Conclusions The use of genotype testing in the management of warfarin anticoagulation was associated with significant improvements in INR-related and clinical outcomes. Thus, genotype-based regimens can be considered a reliable and accurate method to determine warfarin dosing and may be preferred over fixed

  16. 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. PMID:25879963

  17. 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

  18. 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

  19. [Powdered infant formulae preparation guide for hospitals based on Hazard Analysis and Critical Control Points (HACCP) principles].

    PubMed

    Vargas-Leguás, H; Rodríguez Garrido, V; Lorite Cuenca, R; Pérez-Portabella, C; Redecillas Ferreiro, S; Campins Martí, M

    2009-06-01

    This guide for the preparation of powdered infant formulae in hospital environments is a collaborative work between several hospital services and is based on national and European regulations, international experts meetings and the recommendations of scientific societies. This guide also uses the Hazard Analysis and Critical Control Point principles proposed by Codex Alimentarius and emphasises effective verifying measures, microbiological controls of the process and the corrective actions when monitoring indicates that a critical control point is not under control. It is a dynamic guide and specifies the evaluation procedures that allow it to be constantly adapted. PMID:19427820

  20. Design and analysis of a new AUV's sliding control system based on dynamic boundary layer

    NASA Astrophysics Data System (ADS)

    Gao, Fudong; Pan, Cunyun; Han, Yanyan

    2013-01-01

    The new AUV driven by multi-vectored thrusters not only has unique kinematic characteristics during the actual cruise but also exists uncertain factors such as hydrodynamic coefficients perturbation and unknown interference of tail fluid, which bring difficult to the stability of the AUV's control system. In order to solve the nonlinear term and unmodeled dynamics existing in the new AUV's attitude control and the disturbances caused by the external marine environment, a second-order sliding mode controller with double-loop structure that considering the dynamic characteristics of the rudder actuators is designed, which improves the robustness of the system and avoids the control failure caused by the problem that the design theory of the sliding mode controller does not match with the actual application conditions. In order to avoid the loss of the sliding mode caused by the amplitude and rate constraints of the rudder actuator in the new AUV's attitude control, the dynamic boundary layer method is used to adjust the sliding boundary layer thickness so as to obtain the best anti-chattering effects. Then the impacts of system parameters, rudder actuator's constraints and boundary layer on the sliding mode controller are computed and analyzed to verify the effectiveness and robustness of the sliding mode controller based on dynamic boundary layer. The computational results show that the original divergent second-order sliding mode controller can still effectively implement the AUV's attitude control through dynamically adjusting the sliding boundary layer thickness. The dynamic boundary layer method ensures the stability of the system and does not exceed the amplitude constraint of the rudder actuator, which provides a theoretical guidance and technical support for the control system design of the new AUV in real complex sea conditions.

  1. Simulation on a car interior aerodynamic noise control based on statistical energy analysis

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Wang, Dengfeng; Ma, Zhengdong

    2012-09-01

    How to simulate interior aerodynamic noise accurately is an important question of a car interior noise reduction. The unsteady aerodynamic pressure on body surfaces is proved to be the key effect factor of car interior aerodynamic noise control in high frequency on high speed. In this paper, a detail statistical energy analysis (SEA) model is built. And the vibra-acoustic power inputs are loaded on the model for the valid result of car interior noise analysis. The model is the solid foundation for further optimization on car interior noise control. After the most sensitive subsystems for the power contribution to car interior noise are pointed by SEA comprehensive analysis, the sound pressure level of car interior aerodynamic noise can be reduced by improving their sound and damping characteristics. The further vehicle testing results show that it is available to improve the interior acoustic performance by using detailed SEA model, which comprised by more than 80 subsystems, with the unsteady aerodynamic pressure calculation on body surfaces and the materials improvement of sound/damping properties. It is able to acquire more than 2 dB reduction on the central frequency in the spectrum over 800 Hz. The proposed optimization method can be looked as a reference of car interior aerodynamic noise control by the detail SEA model integrated unsteady computational fluid dynamics (CFD) and sensitivity analysis of acoustic contribution.

  2. Delay analysis of networked control systems based on 100 M switched Ethernet.

    PubMed

    Li, Ming

    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

  3. 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.

  4. 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).

  5. 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

    ... Meeting on Proposed Rule AGENCY: Food and Drug Administration, HHS. ACTION: Notification of public meeting... proposed rule to establish requirements for current good manufacturing practice and hazard analysis and risk-based preventive controls for animal food. This proposed rule is one of several proposed...

  6. 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

  7. 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.

  8. 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

  9. Prioritizing risk analysis quality control plans based on Sigma-metrics.

    PubMed

    Westgard, Sten

    2013-03-01

    Six Sigma provides data-driven techniques that can enhance and improve the EP23 risk management approach for formulating quality control (QC) Plans. Risk analysis has significant drawbacks in its ability to identify and appropriately prioritize hazards and failure modes for mitigation of risks. Six Sigma quality management is inherently risk oriented on the basis of the required tolerance limits that define defective products. Six Sigma QC tools provide a quantitative assessment of method performance and an objective selection/design of statistical QC procedures. Furthermore, the observed sigma performance of a method is useful for prioritizing the need for development of QC plans. PMID:23331728

  10. Microarray-based analysis of fish egg quality after natural or controlled ovulation

    PubMed Central

    Bonnet, Emilie; Fostier, Alexis; Bobe, Julien

    2007-01-01

    Background The preservation of fish egg quality after ovulation-control protocols is a major issue for the development of specific biotechnological processes (e.g. nuclear transfer). Depending on the species, it is often necessary to control the timing of ovulation or induce the ovulatory process. The hormonal or photoperiodic control of ovulation can induce specific egg quality defects that have been thoroughly studied. In contrast, the impact on the egg transcriptome as a result of these manipulations has received far less attention. Furthermore, the relationship between the mRNA abundance of maternally-inherited mRNAs and the developmental potential of the egg has never benefited from genome-wide studies. Thus, the present study aimed at studying the rainbow trout (Oncorhynchus mykiss) egg transcriptome after natural or controlled ovulation using 9152-cDNA microarrays. Results The analysis of egg transcriptome after natural or controlled ovulation led to the identification of 26 genes. The expression patterns of 17 of those genes were monitored by real-time PCR. We observed that the control of ovulation by both hormonal induction and photoperiod manipulation induced significant changes in the egg mRNA abundance of specific genes. A dramatic increase of Apolipoprotein C1 (APOC1) and tyrosine protein kinase HCK was observed in the eggs when a hormonal induction of ovulation was performed. In addition, both microarray and real-time PCR analyses showed that prohibitin 2 (PHB2) egg mRNA abundance was negatively correlated with developmental success. Conclusion First, we showed, for the first time in fish, that the control of ovulation using either a hormonal induction or a manipulated photoperiod can induce differences in the egg mRNA abundance of specific genes. While the impact of these modifications on subsequent embryonic development is unknown, our observations clearly show that the egg transcriptome is affected by an artificial induction of ovulation. Second

  11. 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. PMID:26467944

  12. The Stability Analysis for an Extended Car Following Model Based on Control Theory

    NASA Astrophysics Data System (ADS)

    Ge, Hong-Xia; Meng, Xiang-Pei; Zhu, Ke-Qiang; Cheng, Rong-Jun

    2014-08-01

    A new method is proposed to study the stability of the car-following model considering traffic interruption probability. The stability condition for the extended car-following model is obtained by using the Lyapunov function and the condition for no traffic jam is also given based on the control theory. Numerical simulations are conducted to demonstrate and verify the analytical results. Moreover, numerical simulations show that the traffic interruption probability has an influence on driving behavior and confirm the effectiveness of the method on the stability of traffic flow.

  13. 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.

  14. 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.

  15. 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.

  16. 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. PMID:26595398

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Analysis and design of DSP-based dual-loop controlled UPS inverters.

    PubMed

    Wu, Xie-Hua; Yan, Chao

    2003-01-01

    This paper presents a novel digital dual-loop control scheme of the PWM (Pulse width modulate) inverter. Deadbeat control technique are employed to enhance the performance. Half switching period delayed sampling and control tining strategy is used to improve the system dynamic response. Simulation and experimental results presented in the paper verified the validity of the proposed control scheme. PMID:12765279

  3. 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.

  4. 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.

  5. 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. PMID:23516082

  6. 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.

  7. 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.

  8. 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).

  9. 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.

  10. 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. PMID:25402606

  11. 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.

  12. 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. PMID:27588243

  13. 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.

  14. 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.

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

    PubMed Central

    2011-01-01

    Background 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. Methods 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. Results 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. Conclusions 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

  16. 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

  17. Adaptive neuro-fuzzy logic analysis based on myoelectric signals for multifunction prosthesis control.

    PubMed

    Favieiro, Gabriela W; Balbinot, Alexandre

    2011-01-01

    The myoelectric signal is a sign of control of the human body that contains the information of the user's intent to contract a muscle and, therefore, make a move. Studies shows that the Amputees are able to generate standardized myoelectric signals repeatedly before of the intention to perform a certain movement. This paper presents a study that investigates the use of forearm surface electromyography (sEMG) signals for classification of five distinguish movements of the arm using just three pairs of surface electrodes located in strategic places. The classification is done by an adaptive neuro-fuzzy inference system (ANFIS) to process signal features to recognize performed movements. The average accuracy reached for the classification of five motion classes was 86-98% for three subjects. PMID:22256169

  18. 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

  19. 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.

  20. Mindless reading revisited: an analysis based on the SWIFT model of eye-movement control.

    PubMed

    Nuthmann, Antje; Engbert, Ralf

    2009-02-01

    In this article, we revisit the mindless reading paradigm from the perspective of computational modeling. In the standard version of the paradigm, participants read sentences in both their normal version as well as the transformed (or mindless) version where each letter is replaced with a z. z-String scanning shares the oculomotor requirements with reading but none of the higher-level lexical and semantic processes. Here we use the z-string scanning task to validate the SWIFT model of saccade generation [Engbert, R., Nuthmann, A., Richter, E., & Kliegl, R. (2005). SWIFT: A dynamical model of saccade generation during reading. Psychological Review, 112(4), 777-813] as an example for an advanced theory of eye-movement control in reading. We test the central assumption of spatially distributed processing across an attentional gradient proposed by the SWIFT model. Key experimental results like prolonged average fixation durations in z-string scanning compared to normal reading and the existence of a string-length effect on fixation durations and probabilities were reproduced by the model, which lends support to the model's assumptions on visual processing. Moreover, simulation results for patterns of regressive saccades in z-string scanning confirm SWIFT's concept of activation field dynamics for the selection of saccade targets. PMID:19026673

  1. 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

  2. The Effect of Occupation-based Cognitive Rehabilitation for Traumatic Brain Injury: A Meta-analysis of Randomized Controlled Trials.

    PubMed

    Park, Hae Yean; Maitra, Kinsuk; Martinez, Kristina Marie

    2015-06-01

    Traumatic brain injury (TBI) is the leading cause of death and disability among people younger than 35 years in the United States. Cognitive difficulty is a common consequence of TBI. To address cognitive deficits of patients with TBI, various cognitive rehabilitation approaches have been used for the clinical setting. The purpose of this study was to investigate the overall effect of occupation-based cognitive rehabilitation on patients' improvement in cognitive performance components, activity of daily living (ADL) performance, and values, beliefs and spirituality functions of patients with TBI. The papers used in this study were retrieved from the Cochrane Database, EBSCO (CINAHL), PsycINFO, PubMed and Web of Science published between 1997 and 2014. The keywords for searching were cognitive, rehabilitation, occupation, memory, attention, problem-solving, executive function, ADL, values, beliefs, spirituality, randomized controlled trials and TBI. For the meta-analysis, we examined 60 effect sizes from nine studies that are related to the occupation-based cognitive rehabilitation on persons with TBI. In persons with TBI, overall mental functions, ADL, and values, beliefs and spirituality were significantly improved in the groups that received occupation-based cognitive rehabilitation compared with comparison groups (mean d = 0.19, p < .05). Evidence from the present meta-analytic study suggests that occupation-based cognitive rehabilitation would be beneficial for individuals with TBI for improving daily functioning and positively be able to affect their psychosocial functions. Collecting many outcome measures in studies with relatively few participants and the final data are less reliable than the whole instrument itself. Future research should evaluate the effectiveness of specific occupation-based cognitive rehabilitations programmes in order to improve consistency among rehabilitation providers. PMID:25808426

  3. 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. PMID:26708252

  4. 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.

  5. 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.

  6. Effectiveness of tobacco control among Chinese Americans: a comparative analysis of policy approaches versus community-based programs

    PubMed Central

    Shelley, Donna; Fahs, Marianne; Yerneni, Rajeev; Das, Dhiman; Nguyen, Nam; Hung, Dorothy; Burton, Dee; Chin, Margaret; Chang, Ming-der; Cummings, K. Michael

    2008-01-01

    Précis City wide tobacco control policies such as cigarette taxes and smoke free air policies are effective among Chinese immigrants. In addition, community-based tailored tobacco control interventions may increase the reduction in smoking prevalence rates beyond that achieved from public policies. Objective To estimate the effectiveness of a tailored multi component community-based smoking cessation intervention among Chinese immigrants living in NYC, implemented within the context of state and city-wide tobacco control policy initiatives for the general population. Methods A pre-post-test quasi-experimental design with representative samples from Chinese populations living in two communities in NYC: Flushing, Queens, the intervention community and Sunset Park, Brooklyn, the comparison community. From November 2002 to August 2003 baseline interviews were conducted with 2537 adults aged 18–74. In early 2006, 1,384 participants from the original cohort completed the follow-up interview. During the intervention period (October 2003 to September 2005), both communities were exposed to tobacco control public policy changes. However, only Flushing received additional linguistically and culturally-specific community-level tobacco control interventions. Results From 2002 to 2006 overall smoking prevalence among Chinese immigrants declined from 17.7% to 13.6%, a relative 23% decrease. After controlling for sociodemographic characteristics, there was an absolute 3.3% decrease in smoking prevalence attributed to policy changes with an additional absolute decline in prevalence of 2.8% in the intervention community relative to the control community. Conclusion City wide tobacco control policies are effective among high-risk urban communities, such as Chinese immigrants. In addition, community-based tailored tobacco control interventions may increase the reduction in smoking prevalence rates beyond that achieved from public policies. PMID:18687355

  7. 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. PMID:26850751

  8. 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

  9. 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

  10. 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. PMID:25789951

  11. 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

  12. 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.

  13. 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

    ... food authorities participating in the National School Lunch Program (NSLP) or the School Breakfast... participating in the National School Lunch Program (NSLP) or the School Breakfast Program (SBP) to develop a... Service 7 CFR Parts 210 and 220 RIN 0584-AD65 School Food Safety Program Based on Hazard Analysis...

  14. Magnetic study and thermal analysis of a metastable Fe-Zr-based alloy: Influence of process control agents

    NASA Astrophysics Data System (ADS)

    Pilar, M.; Escoda, L.; Suñol, J. J.; Greneche, J. M.

    In this work a Fe 60Co 10(Ni 70Zr 30) 15B 15 nanocrystalline alloy was produced by mechanical alloying. Powders were milled using hexane or cyclohexane as process control agents (PCAs) and their properties compared with those of alloy developed without PCA. Structural and magnetic analysis was performed using X-ray diffraction (XRD), transmission 57Fe Mössbauer spectrometry (TMS) and vibrating sample magnetometry (VSM). High magnetization of saturation and low coercitive field values correspond to an alloy milled with hexane. Thermal analysis was performed by differential scanning calorimetry (DSC). High thermal stability characterizes alloys milled with PCA. Annealing treatments at 400 °C improve magnetic behavior of all samples. Compositional analysis shows low-milling media (<1.1 at.%) and C contamination (<0.2 at.%).

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. A μ analysis-based, controller-synthesis framework for robust bioinspired visual navigation in less-structured environments.

    PubMed

    Keshavan, J; Gremillion, G; Escobar-Alvarez, H; Humbert, J S

    2014-06-01

    Safe, autonomous navigation by aerial microsystems in less-structured environments is a difficult challenge to overcome with current technology. This paper presents a novel visual-navigation approach that combines bioinspired wide-field processing of optic flow information with control-theoretic tools for synthesis of closed loop systems, resulting in robustness and performance guarantees. Structured singular value analysis is used to synthesize a dynamic controller that provides good tracking performance in uncertain environments without resorting to explicit pose estimation or extraction of a detailed environmental depth map. Experimental results with a quadrotor demonstrate the vehicle's robust obstacle-avoidance behaviour in a straight line corridor, an S-shaped corridor and a corridor with obstacles distributed in the vehicle's path. The computational efficiency and simplicity of the current approach offers a promising alternative to satisfying the payload, power and bandwidth constraints imposed by aerial microsystems. PMID:24852145

  1. 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

  2. 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. PMID:27168693

  3. 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.

  4. A model-based analysis of a display for helicopter landing approach. [control theoretical model of human pilot

    NASA Technical Reports Server (NTRS)

    Hess, R. A.; Wheat, L. W.

    1975-01-01

    A control theoretic model of the human pilot was used to analyze a baseline electronic cockpit display in a helicopter landing approach task. The head down display was created on a stroke written cathode ray tube and the vehicle was a UH-1H helicopter. The landing approach task consisted of maintaining prescribed groundspeed and glideslope in the presence of random vertical and horizontal turbulence. The pilot model was also used to generate and evaluate display quickening laws designed to improve pilot vehicle performance. A simple fixed base simulation provided comparative tracking data.

  5. 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. PMID:24814559

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

    PubMed Central

    Lenehan, Claire E.; 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 × 10-10 to 5 × 10-6 M) with a line of best fit of y=1.05x+8.9164 (R2 =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 × 10-8 M). The limit of detection (3σ) was determined as 5 × 10-11 M morphine. PMID:18924729

  7. Efavirenz-Based Regimens in Antiretroviral-Naive HIV-Infected Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Kryst, Joanna; Kawalec, Paweł; Pilc, Andrzej

    2015-01-01

    Efavirenz, a non-nucleoside reverse-transcriptase inhibitor (NNRTI) is one of the most commonly prescribed antiretroviral drugs. The present article provides a systematic overview and meta-analysis of clinical trials comparing efavirenz and other active drugs currently recommended for treatment of HIV-infected, antiretroviral-naive patients. Electronic databases (Pubmed, Embase, the Cochrane Library, Trip Database) were searched up till 23 December 2013 for randomized controlled clinical trials published as a peer-reviewed papers, and concerning efavirenz-based regimens used as initial treatment for HIV infection. Thirty-four studies were included in the systematic review, while twenty-six trials were suitable for the meta-analysis. Efavirenz was compared with drugs from four different classes: NNRTIs other than efavirenz (nevirapine or rilpivirine), integrase strand transfer inhibitors (InSTIs), ritonavir-boosted protease inhibitors (bPI) and chemokine (C-C motif) receptor 5 (CCR5) antagonists (maraviroc), all of them were added to the background regimen. Results of the current meta-analysis showed that efavirenz-based regimens were equally effective as other recommended regimens based on NNRTI, ritonavir-boosted PI or CCR5 antagonist in terms of efficacy outcomes (disease progression and/or death, plasma viral HIV RNA <50 copies/ml) while statistically significant more patients treated with InSTI achieved plasma viral load <50 copies/ml at week 48. In comparison with both InSTI-based and CCR5-based therapy, efavirenz-based treatment was associated with a higher risk of therapy discontinuation due to adverse events. However, comparisons of efevirenz-based treatment with InSTI-based and CCR5-based therapy were based on a limited number of trials, therefore, conclusions from these two comparisons must be confirmed in further reliable randomized controlled studies. Results of our meta-analysis support the present clinical guidelines for antiretroviral-naive, HIV

  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. PMID:18614358

  9. 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.

  10. 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.

  11. Total waste-load control and allocation based on input-output analysis for Shenzhen, south China.

    PubMed

    Ni, J R; Zhong, D S; Huang, Y F; Wang, H

    2001-01-01

    The general objective for this paper is to reveal the dynamic relationships between the rapid economic development, water pollution and the subsequent waste-load allocation in different economic sectors through a case-study in Shenzhen City, South China. Two-objective analysis model was employed based on the input-output table for Shenzhen with the full consideration of various constraints in local area. The improved Tchebycheff procedure was used for obtaining the solutions. The predictions were made on economic development and pollutants from wastewater in different sectors and different planning years. The present study allows for the consideration of the economic structural adjustment. It is found that the current situation of economic structure is generally good and is subject to further adjustment in Shenzhen, although it has undergone the rapid development in the past 18 years. When the maximum Gross Domestic Production and the minimum Chemical Oxygen Demand are chosen as the two objectives subject to other constraints, the harmonized results indicated a scheme that claims substantial reduction of polluting effluences in Shenzhen while closely keeping the economic growth rate as planned. PMID:11381457

  12. 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

  13. Efficacy and Cardiotoxicity of Liposomal Doxorubicin-Based Chemotherapy in Advanced Breast Cancer: A Meta-Analysis of Ten Randomized Controlled Trials

    PubMed Central

    Xing, Meiyuan; Yan, Feifei; Yu, Sufen; Shen, Peng

    2015-01-01

    Background Various trials have compared the efficacy and toxicity of liposomal doxorubicin-based chemotherapy with the conventional formulation of doxorubicin although arriving at inconsistent conclusions. To derive a conclusive assessment of the efficacy and cardiotoxicity associated with chemotherapy, we performed a meta-analysis by combining data from all eligible randomized controlled trials. Methods We used the PubMed database to identify relevant studies published through December 28, 2014. Eligible studies included randomized controlled trials directly comparing the efficacy and cardiotoxicity of liposomal doxorubicin-based chemotherapy with conventional doxorubicin in advanced breast cancer with adequate data. Odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) were used to assess the efficacy and cardiotoxicity in a fixed-effects or random-effects model. Results Ten randomized controlled trials containing efficacy and data from a total of 2,889 advanced breast cancer patients were included in this report. Liposomal doxorubicin-based chemotherapy was associated with a significant reduction in the risk of cardiotoxicity (OR = 0.46, 95% CI 0.23 to 0.92, p = 0.03) and a significant improvement in the overall response rate (ORR) (OR = 1.25, 95% CI 1.02 to 1.52, p=0.03) compared with conventional doxorubicin. An apparent improvement in progression-free survival (PFS) for patients treated with liposomal doxorubicin-based chemotherapy was noted; however, this difference was not significant (HR = 1.14, 95% CI 0.96 to 1.34, p = 0.12). In terms of overall survival (OS), no significant difference between the two chemotherapy regimens was noted (HR = 1.00, 95% CI 0.91 to 1.10, p = 0.93). Conclusion The results of this meta-analysis suggest that liposomal doxorubicin-based chemotherapy is associated with a significant improvement in the ORR and a significant reduction in the risk of cardiotoxicity. PMID:26204517

  14. 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.

  15. 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.

  16. 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.

  17. Development of quality control data base ``DANTE'' and relational analysis between fission gas release behavior and plutonium homogeneity in mixed oxide fuel by DANTE

    NASA Astrophysics Data System (ADS)

    Takahashi, K.; Kamimura, K.; Yamaguchi, T.; Masuda, S.

    1988-04-01

    The PNC Plutonium Fabrication Facility (PPFF) of Tokai Works of the "Power Reactor and Nuclear Fuel Development Corporation" (PNC) has produced several types of mixed oxide fuels which have been used as the fuels for the Advanced Thermal Reactor FUGEN, and the Experimental Fast Reactor JOYO. Accumulated production of MOX fuel is about 58000 pins as of December, 1986. PPFF production technique is so reliable that no failure of driver fuel pins has been found in the FUGEN and JOYO. This is based on the adequate process control and quality control. In this paper the outline of quality control method applied to MOX fuels in our facility will be reviewed. The discussion is done mainly on the viewpoint of the software system including data gathering, data analysis and data storage, etc. The code system, Data Analysing Technology for Engineers, DANTE, has been developed for this purpose. The DANTE code system is consisted of real time system having relational data base. It is possible to refer the data base relationally and to make tables and figures of the analyzed results on real time by using the DANTE code system. The DANTE code system contributes to quality assurance in the MOX Fuel production facility by evaluating overall data which come from each process such as production and inspection processes.

  18. 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.

  19. Association of folate-pathway gene polymorphisms with the risk of prostate cancer: a population-based nested case-control study, systematic review, and meta-analysis.

    PubMed

    Collin, Simon M; Metcalfe, Chris; Zuccolo, Luisa; Lewis, Sarah J; Chen, Lina; Cox, Angela; Davis, Michael; Lane, J Athene; Donovan, Jenny; Smith, George Davey; Neal, David E; Hamdy, Freddie C; Gudmundsson, Julius; Sulem, Patrick; Rafnar, Thorunn; Benediktsdottir, Kristrun R; Eeles, Rosalind A; Guy, Michelle; Kote-Jarai, Zsofia; Morrison, Jonathan; Al Olama, Ali Amin; Stefansson, Kari; Easton, Douglas F; Martin, Richard M

    2009-09-01

    Folate-pathway gene polymorphisms have been implicated in several cancers and investigated inconclusively in relation to prostate cancer. We conducted a systematic review, which identified nine case-control studies (eight included, one excluded). We also included data from four genome-wide association studies and from a case-control study nested within the UK population-based Prostate Testing for Cancer and Treatment study. We investigated by meta-analysis the effects of eight polymorphisms: MTHFR C677T (rs1801133; 12 studies; 10,745 cases; 40,158 controls), MTHFR A1298C (rs1801131; 5 studies; 3,176 cases; 4,829 controls), MTR A2756G (rs1805087; 8 studies; 7,810 cases; 37,543 controls), MTRR A66G (rs1801394; 4 studies; 3,032 cases; 4,515 controls), MTHFD1 G1958A (rs2236225; 6 studies; 7,493 cases; 36,941 controls), SLC19A1/RFC1 G80A (rs1051266; 4 studies; 6,222 cases; 35,821 controls), SHMT1 C1420T (rs1979277; 2 studies; 2,689 cases; 4,110 controls), and FOLH1 T1561C (rs202676; 5 studies; 6,314 cases; 35,190 controls). The majority (10 of 13) of eligible studies had 100% Caucasian subjects; only one study had <90% Caucasian subjects. We found weak evidence of dominant effects of two alleles: MTR 2756A>G [random effects pooled odds ratio, 1.06 (1.00-1.12); P = 0.06 (P = 0.59 for heterogeneity across studies)] and SHMT1 1420C>T [random effects pooled odds ratio, 1.11 (1.00-1.22); P = 0.05 (P = 0.38 for heterogeneity across studies)]. We found no effect of MTHFR 677C>T or any of the other alleles in dominant, recessive or additive models, or in comparing a/a versus A/A homozygous. Neither did we find any difference in effects on advanced or localized cancers. Our meta-analysis suggests that known common folate-pathway single nucleotide polymorphisms do not have significant effects on susceptibility to prostate cancer. PMID:19706844

  20. 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.

  1. 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

  2. Efficacy and safety of capecitabine-based first-line chemotherapy in advanced or metastatic breast cancer: a meta-analysis of randomised controlled trials

    PubMed Central

    Liu, Gang; Huang, Li; Gao, Shegan; Feng, Xiaoshan

    2015-01-01

    We sought to evaluate the efficacy and safety of capecitabine-based therapy as first-line chemotherapy in advanced breast cancer. Randomised controlled trials of capecitabine monotherapy or combined treatment were included in the meta-analysis. PubMed, EMBASE, the Cochrane Library database and important meeting summaries were searched systematically. Outcomes were progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and grades 3–4 drug-related adverse events. Nine trials with 1798 patients were included. The results indicated a significant improvement with capecitabine-based chemotherapy compared with capecitabine-free chemotherapy in ORR (relative risk [RR] 1.14, 95% confidence interval [CI] 1.03 to 1.26, P = 0.013) and PFS (hazard ratio [HR] 0.77, 95% CI 0.69 to 0.87, P < 0.0001). Overall survival favoured capecitabine-based chemotherapy, but this was not significant. There were more incidences of neutropenia and neutropenic fever in the capecitabine-free chemotherapy group and more vomiting, diarrhoea and hand–foot syndrome in the capecitabine-based chemotherapy group. There were no significant differences in nausea, fatigue, cardiotoxicity or mucositis/stomatitis between the two treatment regimens. Capecitabine-based chemotherapy significantly improves ORR and PFS in patients with advanced breast cancer, but has no demonstrable impact on OS. Capecitabine-based regimens are suitable as first-line treatment for patients with advanced breast cancer. PMID:26420815

  3. Efficacy and safety of capecitabine-based first-line chemotherapy in advanced or metastatic breast cancer: a meta-analysis of randomised controlled trials.

    PubMed

    Yin, Weijiao; Pei, Guangsheng; Liu, Gang; Huang, Li; Gao, Shegan; Feng, Xiaoshan

    2015-11-17

    We sought to evaluate the efficacy and safety of capecitabine-based therapy as first-line chemotherapy in advanced breast cancer. Randomised controlled trials of capecitabine monotherapy or combined treatment were included in the meta-analysis. PubMed, EMBASE, the Cochrane Library database and important meeting summaries were searched systematically. Outcomes were progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and grades 3-4 drug-related adverse events.Nine trials with 1798 patients were included. The results indicated a significant improvement with capecitabine-based chemotherapy compared with capecitabine-free chemotherapy in ORR (relative risk [RR] 1.14, 95% confidence interval [CI] 1.03 to 1.26, P = 0.013) and PFS (hazard ratio [HR] 0.77, 95% CI 0.69 to 0.87, P < 0.0001). Overall survival favoured capecitabine-based chemotherapy, but this was not significant. There were more incidences of neutropenia and neutropenic fever in the capecitabine-free chemotherapy group and more vomiting, diarrhoea and hand-foot syndrome in the capecitabine-based chemotherapy group. There were no significant differences in nausea, fatigue, cardiotoxicity or mucositis/stomatitis between the two treatment regimens.Capecitabine-based chemotherapy significantly improves ORR and PFS in patients with advanced breast cancer, but has no demonstrable impact on OS. Capecitabine-based regimens are suitable as first-line treatment for patients with advanced breast cancer. PMID:26420815

  4. Is Traumatic Brain Injury A Risk Factor for Schizophrenia? A Meta-Analysis of Case-Controlled Population-Based Studies

    PubMed Central

    Molloy, Charlene; Conroy, Ronan M.; Cotter, David R.; Cannon, Mary

    2011-01-01

    Traumatic brain injury (TBI) is known to lead to a range of adverse psychiatric sequelae but the question of whether TBI is a risk factor for psychosis and, in particular, schizophrenia remains unclear. Studies examining this issue have yielded conflicting results. We carried out a systematic review of the literature on TBI and psychosis in order to identify all population-based controlled studies which provide estimates of risk for schizophrenia following TBI. Odds ratios (ORs) were combined using random effects meta-analysis. Our literature search yielded 172 studies which were considered to be potentially relevant. From these, we identified 9 studies that could provide estimates of risk in the form of ORs. The pooled analysis revealed a significant association between TBI and schizophrenia (OR = 1.65; 95% CI = 1.17–2.32), with significant heterogeneity between the studies. Estimates from the family studies (OR = 2.8: 95% CI =1.76–4.47) were higher than those from the cohort/nested case-control studies (OR = 1.42: 95% CI = 1.02–1.97) by a factor of almost 2. There did not appear to be a dose-response relationship between severity of head injury and subsequent risk of schizophrenia. This meta-analysis supports an increased risk of schizophrenia following TBI, with a larger effect in those with a genetic predisposition to psychosis. Further epidemiological and neuroscientific studies to elucidate the mechanisms underlying this association are warranted. PMID:21813439

  5. 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.

  6. 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.

  7. A windows based automated quality control system for the ICP-AES analysis of Waste Isolation Pilot Plant (WIPP) brines

    SciTech Connect

    Gerth, D.J.

    1996-09-01

    High sample volume analytical laboratories typically require automation of tasks to maximize efficiency and productivity. Typical approaches target instrument operation and data reporting (LIMS), but frequently ignore the data evaluation and run time QC aspects. Automation of these steps can save up to 50% of the time it takes to analyze, evaluate, and report data from a typical ICP-AES run. The program developed in this project addresses this need by performing a CLP-style evaluation of the run time QC data included in an instrument run. Written in Microcraft Visual Basic 3.0, it makes use of a Microsoft Access database to store method parameters and QC sample results for control charting. In operation, the analyst enters method background data (e.g., control samples types and acceptance criteria for each analyte), which is then stored in the method database. Once the method parameters are entered, instrument data files may be imported for review. Upon import, the run is automatically checked against desired QC criteria, QC sample data are added to the database, and failing samples flagged appropriately. Analytes passing all QC checks are flagged for upload to the laboratory LIMS. The analyst may then review the run sample by sample, and, if desired, override the computer upload flag. An exception report may be generated detailing samples that require reanalysis.

  8. 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

  9. Internet and Computer-Based Cognitive Behavioral Therapy for Anxiety and Depression in Youth: A Meta-Analysis of Randomized Controlled Outcome Trials

    PubMed Central

    Ebert, David Daniel; Zarski, Anna-Carlotta; Christensen, Helen; Stikkelbroek, Yvonne; Cuijpers, Pim; Berking, Matthias; Riper, Heleen

    2015-01-01

    Background Anxiety and depression in children and adolescents are undertreated. Computer- and Internet-based cognitive behavioral treatments (cCBT) may be an attractive treatment alternative to regular face-to-face treatment.This meta-analysis aims to evaluate whether cCBT is effective for treating symptoms of anxiety and depression in youth. Methods and Findings We conducted systematic searches in bibliographical databases (Pubmed, Cochrane controlled trial register, PsychInfo) up to December 4, 2013. Only randomized controlled trials in which a computer-, Internet- or mobile-based cognitive behavioral intervention targeting either depression, anxiety or both in children or adolescents up to the age of 25 were compared to a control condition were selected. We employed a random-effects pooling model in overall effect analyses and a mixed effect model for sub-group analyses. Searches resulted in identifying 13 randomized trials, including 796 children and adolescents that met inclusion criteria. Seven studies were directed at treating anxiety, four studies at depression, and two were of a transdiagnostic nature, targeting both anxiety and depression. The overall mean effect size (Hedges’ g) of cCBT on symptoms of anxiety or depression at post-test was g=0.72 (95% CI:0.55-0.90, numbers needed to be treated (NNT)=2.56). Heterogeneity was low (I²=20.14%, 95% CI: 0-58%). The superiority of cCBT over controls was evident for interventions targeting anxiety (g=0.68; 95% CI: 0.45-0.92; p < .001; NNT=2.70) and for interventions targeting depression (g=0.76; 95% CI: 0.41-0.12; p < .001; NNT=2.44) as well as for transdiagnostic interventions (g=0.94; 95% CI: 0.23-2.66; p < .001; NNT=2.60). Conclusions Results provide evidence for the efficacy of cCBT in the treatment of anxiety and depressive symptoms in youth. Hence, such interventions may be a promising treatment alternative when evidence based face-to-face treatment is not feasible. Future studies should examine long

  10. Tight glycemic control in critical care--the leading role of insulin sensitivity and patient variability: a review and model-based analysis.

    PubMed

    Chase, J Geoffrey; Le Compte, Aaron J; Suhaimi, Fatanah; Shaw, Geoffrey M; Lynn, Adrienne; Lin, Jessica; Pretty, Christopher G; Razak, Normy; Parente, Jacquelyn D; Hann, Christopher E; Preiser, Jean-Charles; Desaive, Thomas

    2011-05-01

    Tight glycemic control (TGC) has emerged as a major research focus in critical care due to its potential to simultaneously reduce both mortality and costs. However, repeating initial successful TGC trials that reduced mortality and other outcomes has proven difficult with more failures than successes. Hence, there has been growing debate over the necessity of TGC, its goals, the risk of severe hypoglycemia, and target cohorts. This paper provides a review of TGC via new analyses of data from several clinical trials, including SPRINT, Glucontrol and a recent NICU study. It thus provides both a review of the problem and major background factors driving it, as well as a novel model-based analysis designed to examine these dynamics from a new perspective. Using these clinical results and analysis, the goal is to develop new insights that shed greater light on the leading factors that make TGC difficult and inconsistent, as well as the requirements they thus impose on the design and implementation of TGC protocols. A model-based analysis of insulin sensitivity using data from three different critical care units, comprising over 75,000h of clinical data, is used to analyse variability in metabolic dynamics using a clinically validated model-based insulin sensitivity metric (S(I)). Variation in S(I) provides a new interpretation and explanation for the variable results seen (across cohorts and studies) in applying TGC. In particular, significant intra- and inter-patient variability in insulin resistance (1/S(I)) is seen be a major confounder that makes TGC difficult over diverse cohorts, yielding variable results over many published studies and protocols. Further factors that exacerbate this variability in glycemic outcome are found to include measurement frequency and whether a protocol is blind to carbohydrate administration. PMID:21145614

  11. Java based open architecture controller

    SciTech Connect

    Weinert, G F

    2000-01-13

    At Lawrence Livermore National Laboratory (LLNL) the authors have been developing an open architecture machine tool controller. This work has been patterned after the General Motors (GM) led Open Modular Architecture Controller (OMAC) work, where they have been involved since its inception. The OMAC work has centered on creating sets of implementation neutral application programming interfaces (APIs) for machine control software components. In the work at LLNL, they were among the early adopters of the Java programming language. As an application programming language, it is particularly well suited for component software development. The language contains many features, which along with a well-defined implementation API (such as the OMAC APIs) allows third party binary files to be integrated into a working system. Because of its interpreted nature, Java allows rapid integration testing of components. However, for real-time systems development, the Java programming language presents many drawbacks. For instance, lack of well defined scheduling semantics and threading behavior can present many unwanted challenges. Also, the interpreted nature of the standard Java Virtual Machine (JVM) presents an immediate performance hit. Various real-time Java vendors are currently addressing some of these drawbacks. The various pluses and minuses of using the Java programming language and environment, with regard to a component-based controller, will be outlined.

  12. 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.

  13. 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

  14. 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

  15. TARA control, data acquisition and analysis system

    SciTech Connect

    Gaudreau, M.P.J.; Sullivan, J.D.; Fredian, T.W.; Karcher, C.A.; Sevillano, E.; Stillerman, J.; Thomas, P.

    1983-12-01

    The MIT tandem mirror (TARA) control, data acquisition and analysis system consists of two major parts: (1) a Gould 584 industrial programmable controller (PC) to control engineering functions; and (2) a VAX 11/750 based data acquisition and analysis system for physics analysis. The PC is designed for use in harsh industrial environments and has proven to be a reliable and cost-effective means for automated control. The PC configuration is dedicated to control tasks on the TARA magnet, vacuum, RF, neutral beam, diagnostics, and utility systems. The data transfer functions are used to download system operating parameters from menu selectable tables. Real time status reports are provided to video terminals and as blocks of data to the host computer for storage. The data acquisition and analysis system for TARA was designed to provide high throughput and ready access to data from earlier runs. The adopted design uses pre-existing software packages in a system which is simple, coherent, fast, and which requires a minimum of new software development. The computer configuration is a VAX 11/750 running VMS with 124 M byte massbus disk and 1.4 G byte unibus disk subsystem.

  16. mtDNAmanager: a Web-based tool for the management and quality analysis of mitochondrial DNA control-region sequences

    PubMed Central

    Lee, Hwan Young; Song, Injee; Ha, Eunho; Cho, Sung-Bae; Yang, Woo Ick; Shin, Kyoung-Jin

    2008-01-01

    Background For the past few years, scientific controversy has surrounded the large number of errors in forensic and literature mitochondrial DNA (mtDNA) data. However, recent research has shown that using mtDNA phylogeny and referring to known mtDNA haplotypes can be useful for checking the quality of sequence data. Results We developed a Web-based bioinformatics resource "mtDNAmanager" that offers a convenient interface supporting the management and quality analysis of mtDNA sequence data. The mtDNAmanager performs computations on mtDNA control-region sequences to estimate the most-probable mtDNA haplogroups and retrieves similar sequences from a selected database. By the phased designation of the most-probable haplogroups (both expected and estimated haplogroups), mtDNAmanager enables users to systematically detect errors whilst allowing for confirmation of the presence of clear key diagnostic mutations and accompanying mutations. The query tools of mtDNAmanager also facilitate database screening with two options of "match" and "include the queried nucleotide polymorphism". In addition, mtDNAmanager provides Web interfaces for users to manage and analyse their own data in batch mode. Conclusion The mtDNAmanager will provide systematic routines for mtDNA sequence data management and analysis via easily accessible Web interfaces, and thus should be very useful for population, medical and forensic studies that employ mtDNA analysis. mtDNAmanager can be accessed at . PMID:19014619

  17. 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…

  18. 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. PMID:26198135

  19. Atom-Role-Based Access Control Model

    NASA Astrophysics Data System (ADS)

    Cai, Weihong; Huang, Richeng; Hou, Xiaoli; Wei, Gang; Xiao, Shui; Chen, Yindong

    Role-based access control (RBAC) model has been widely recognized as an efficient access control model and becomes a hot research topic of information security at present. However, in the large-scale enterprise application environments, the traditional RBAC model based on the role hierarchy has the following deficiencies: Firstly, it is unable to reflect the role relationships in complicated cases effectively, which does not accord with practical applications. Secondly, the senior role unconditionally inherits all permissions of the junior role, thus if a user is under the supervisor role, he may accumulate all permissions, and this easily causes the abuse of permission and violates the least privilege principle, which is one of the main security principles. To deal with these problems, we, after analyzing permission types and role relationships, proposed the concept of atom role and built an atom-role-based access control model, called ATRBAC, by dividing the permission set of each regular role based on inheritance path relationships. Through the application-specific analysis, this model can well meet the access control requirements.

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

    PubMed Central

    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. PMID:26581107

  1. 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. PMID:27111302

  2. Multicentre aneurysm screening study (MASS): cost effectiveness analysis of screening for abdominal aortic aneurysms based on four year results from randomised controlled trial

    PubMed Central

    2002-01-01

    Objective To assess the cost effectiveness of ultrasound screening for abdominal aortic aneurysms. Design Primary analysis: four year cost effectiveness analysis based directly on results from a randomised controlled trial in which patients were individually allocated to invitation to ultrasound screening (intervention) or to a control group not offered screening. Secondary analysis: projection of the data, based on conservative assumptions, to indicate likely cost effectiveness at 10 years. Setting Four centres in the United Kingdom. Screening delivered in primary care settings with follow up and surgery offered in the main hospitals Participants Population based sample of 67 800 men aged 65-74 years. Main outcome measures Mortality from and costs (screening, follow up, elective and emergency surgery) related to abdominal aortic aneurysm; cost per life year gained. Results Over four years there were 47 fewer deaths related to abdominal aortic aneurysms in the screening group than in the control group, but the additional costs incurred were £2.2m. After adjustment for censoring and discounted at 6% the mean additional cost of the screening programme was £63.39 ($97.77, €100.48) (95% confidence interval £53.31 to £73.48) per patient. The hazard ratio for abdominal aortic aneurysm was 0.58 (0.42 to 0.78). Over four years the mean incremental cost effectiveness ratio for screening was £28 400 (£15 000 to £146 000) per life year gained, equivalent to about £36 000 per quality adjusted life year. After 10 years this figure is estimated to fall to around £8000 per life year gained. Conclusions Even at four years the cost effectiveness of screening for abdominal aortic aneurysms is at the margin of acceptability according to current NHS thresholds. Over a longer period the cost effectiveness will improve substantially, the predicted ratio at 10 years falling to around a quarter of the four year figure. What is already known on this topicSmall trials

  3. Comparative study of SPR and ELISA methods based on analysis of CD166/ALCAM levels in cancer and control human sera.

    PubMed

    Vaisocherová, Hana; Faca, Vitor M; Taylor, Allen D; Hanash, Samir; Jiang, Shaoyi

    2009-03-15

    Surface plasmon resonance (SPR), as a label free method for analysis of various analytes, has significantly advanced in recent years. However, assessment of the performance of SPR compared to label-based immunoassays such as the commonly used multiplexed enzyme-linked immunosorbent assay (ELISA) is limited, particularly for applications involving complex media. In this work, an optimized SPR assay was implemented and its performance compared with an ELISA assay for CD166/activated cell leukocyte adhesion molecule (ALCAM), as candidate pancreatic cancer marker, based on direct and amplified detection in buffer and in human serum samples from healthy individuals and subjects with cancer. ALCAM antibody was immobilized on the surface of a four-channel SPR sensor via physical adsorption onto charged amine-terminated alkanethiolates to mimic the ELISA plate surface. Excellent correlations between SPR and ELISA results were achieved in buffer and in human serum. SPR detected the target protein with a similar sensitivity to sandwich ELISA, with a detection limit below ng/mL. The detection time, sample consumption, throughput, signal referencing, and surface blocking and washing for detection in human serum were evaluated. It is demonstrated that SPR can distinguish between ALCAM levels in cancer and control sera using direct detection without the need for additional amplification steps. PMID:19157844

  4. 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

  5. Association between Maternal MTHFR Polymorphisms and Nonsyndromic Cleft Lip with or without Cleft Palate in Offspring, A Meta-Analysis Based on 15 Case-Control Studies

    PubMed Central

    Pan, Xinjuan; Wang, Ping; Yin, Xinjuan; Liu, Xiaozhuan; Li, Di; Li, Xing; Wang, Yongchao; Li, Hongle; Yu, Zengli

    2015-01-01

    Background The methylenetetrahydrofolate reductase (MTHFR) is thought to be involved in the development of nonsyndromic cleft lip with or without cleft palate (NSCL/P). However, conflicting results have been obtained when evaluating the association between maternal MTHFR C677T and A1298C polymorphisms and the risk of NSCL/P. In light of this gap, a meta-analysis of all eligible case-control studies was conducted in the present study. Materials and Methods A total of 15 case-control studies were ultimately identified after a comprehensive literature search and Hardy-Weinberg equilibrium (HWE) examination. Cochrane’s Q test and index of heterogeneity (I2) indicated no obvious heterogeneity among studies. Results Fixed or random-effects models were used to calculate the pooled odds ratios (ORs). The results showed that the TT genotype in mothers increased the likelihood of having NSCL/P offspring 1.25 times (95% CI: 1.047-1.494) more than the CC homozygotes. Meanwhile, maternal TT genotype increased the risk of producing NSCL/P offspring in recessive model (OR=1.325, 95% CI: 1.124-1.562). However, the CT heterozygote and the CT+TT dominant models had no association with NSCL/P offspring compared with the CC wild-type homozygote model. Subgroup analyses based on ethnicity indicated that maternal TT genotype increased the likelihood of having NSCL/P offspring in Whites (OR=1.308, 95% CI: 1.059-1.617) and Asians (OR=1.726, 95% CI: 1.090-2.733) in recessive model. Also, subgroup analyses based on source of control showed that mothers with the 677TT genotype had a significantly increased susceptibility of having NSCL/P children in hospital based population (HB) when compared with CC homozygotes (OR=1.248, 95% CI: 1.024-1.520) and un- der the recessive model (OR=1.324, 95% CI: 1.104-1.588). Furthermore, maternal A1298C polymorphism had no significant association with producing NSCL/P offspring (dominant model OR=0.952, 95% CI: 0.816-1.111, recessive model OR=0.766, 95% CI

  6. Microprocessor based control for wind turbines

    SciTech Connect

    Absi, M.; Dodd, C.

    1980-01-01

    This paper will discuss the design of a microprocessor based control system for a Vertical Axis Wind Turbine (VAWT). A control philosophy is developed and the reasons for a microprocessor control are discussed. 5 refs.

  7. 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

  8. 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.

  9. 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

  10. Chinese Herbal Medicine and Fluorouracil-Based Chemotherapy for Colorectal Cancer: A Quality-Adjusted Meta-Analysis of Randomized Controlled Trials.

    PubMed

    McCulloch, Michael; Ly, Helen; Broffman, Michael; See, Caylie; Clemons, Jen; Chang, Raymond

    2016-09-01

    Background Chinese herbal medicines reportedly increase efficacy and minimize toxicity of chemotherapy; however, little attention has been paid to how poor study quality can bias outcomes. Methods We systematically searched MEDLINE, TCMLARS, EMBASE, and Cochrane Library for randomized controlled trials of Chinese herbal medicines combined with fluorouracil-based chemotherapy compared with the same chemotherapy alone. We screened for eligibility, extracted data, and pooled data with random-effects meta-analysis. Outcome measures were survival, toxicity, tumor response, performance status, quality of life, and Cochrane Risk of Bias (ROB) criteria to critically evaluate the quality of reporting in the randomized trials included in the meta-analysis. Results We found 36 potentially eligible studies, with only 3 (those with low ROB) qualifying for meta-analysis. Two reported chemotherapy-related diarrhea reduced by 57% (relative risk [RR] = 0.43; 95% CI = 0.19-1.01; I(2) test for variation in RR due to heterogeneity = 0.0%), with nonsignificant results. Two reported white blood cell toxicity reduced by 66% (RR = 0.34; 95% CI = 0.16-0.72; I(2) test for variation in RR due to heterogeneity = 0.0%), with statistically significant results. Stratifying analysis by studies with high versus low ROB, we found substantial overestimation of benefit: Studies with high ROB overestimated by nearly 2-fold reduction of platelet toxicity by Chinese herbal medicines (RR = 0.35, 95% CI = 0.15-0.84 vs RR = 0.65, 95% CI = 0.11-3.92). Studies with high ROB overestimated by nearly 2-fold reduction of vomiting toxicity (RR = 0.45, 95% CI = 0.33-0.61 vs RR = 0.87, 95% CI = 0.48-1.58). And, studies with high ROB overestimated by 21% the reduction in diarrhea toxicity (RR = 0.34, 95% CI = 0.20-0.58 vs RR = 0.43, 95% CI = 0.19-1.01). Studies with high ROB also overestimated by 16% improvement in tumor response (RR = 1.39, 95% CI = 1.18-1.63 vs RR = 1.20; 95% CI = 0.81-1.79). Not accounting for

  11. Summary and analysis of prototypic current control

    SciTech Connect

    Reich, J.E.; Pike, C.T.

    1993-12-31

    A synopsis of current control operational history at the CDIF is presented. A brief discussion of the current control function is provided, along with the rationale and background of previous current control activities. Current control circuit performance during channel power operations is then reviewed. The review reveals that the circuits performed without failure for normal channel operations, including large load current fluctuations, and tests following emergency shutdowns. The mode of failure of the current control circuits which failed during off-normal conditions was analyzed using a computer program to model the electrical behavior. The circuit analysis clearly demonstrated that the circuits can be overstressed when subjected to extraordinary fault conditions and cause component failures as a result of the applied transients. Based upon the operational history and analysis of the failed circuits, it is determined that the circuits are adequately designed for their intended purpose. They have proven reliable for hundreds of hours of testing over a wide variety of operating conditions, and function properly to enhance channel lifetime by conditioning the current profiles and protecting the channel from adverse voltages.

  12. 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.

  13. The role of WWOX polymorphisms on COPD susceptibility and pulmonary function traits in Chinese: a case-control study and family-based analysis

    PubMed Central

    Xie, Chenli; Chen, Xiaoliang; Qiu, Fuman; Zhang, Lisha; Wu, Di; Chen, Jiansong; Yang, Lei; Lu, Jiachun

    2016-01-01

    Single nucleotide polymorphisms (SNPs) in the WW domain containing oxidoreductase (WWOX) gene were recently identified to be quantitative trait loci for lung function and thus likely to be susceptible biomarkers for COPD. However, the associations between WWOX SNPs and COPD risk are still unclear. Here, by conducting a two-center case-control study including 1511 COPD cases and 1677 controls and a family-based analysis comprising 95 nuclear pedigrees, we tested the associations between five SNPs that are rs10220974C >T, rs3764340C >G, rs12918952G >A, rs383362G >T, rs12828G >A of WWOX and COPD risk as well as the hereditary inclination of these loci among COPD families. We found that the SNP rs383362G >T was significantly associated with an increased risk of COPD in a T allele-number dependent-manner (OR = 1.30, 95%CI = 1.11 - 1.52). The T allele was more prone to over transmit to sick children and sibs than the G allele (Z = 2.900, P = 0.004). Moreover, the forced expiratory volume in one second/forced vital capacity (FEV1/FVC), FEV1/predicted-FEV1 and annual FEV1 also significantly decreased in the rs383362T carriers compared to the rs383362GG carriers. For other SNPs, no significant association was observed for COPD and pulmonary function. Taken together, our data demonstrated that the SNP rs383362G >T of WWOX plays a role in COPD inheritance. PMID:26902998

  14. Modification of breast cancer risk according to age and menopausal status: A combined analysis of five population-based case-control studies

    PubMed Central

    Trentham-Dietz, Amy; Sprague, Brian L.; Hampton, John M.; Miglioretti, Diana L.; Nelson, Heidi D.; Titus, Linda J.; Egan, Kathleen M.; Remington, Patrick L.; Newcomb, Polly A.

    2014-01-01

    Purpose While several risk factors for breast cancer have been identified, studies have not consistently shown whether these factors operate more strongly at certain ages or for just pre- or postmenopausal women. We evaluated whether risk factors for breast cancer differ according to age or menopausal status. Methods Data from five population-based case-control studies conducted during 1988-2008 were combined and analyzed. Cases (N=23,959) and population controls (N=28,304) completed telephone interviews. Logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals and tests for interaction by age and menopausal status. Results Odds ratios for first-degree family history of breast cancer were strongest for younger women—reaching two-fold elevations—but were still statistically significantly elevated by 58-69% among older women. Obesity was inversely associated with breast cancer among younger women and positively associated with risk for older women (interaction P<0.0001). Recent alcohol intake was more strongly related to breast cancer risk among older women, although consumption of 3 or more drinks/day among younger women also was associated with elevated odd ratios (P<0.0001). Associations with benign breast disease and most reproductive/menstrual factors did not vary by age. Repeating analysis stratifying by menopausal status produced similar results. Conclusions With few exceptions, menstrual and lifestyle factors are associated with breast cancer risk regardless of age or menopausal status. Variation in the association of family history, obesity, and alcohol use with breast cancer risk by age and menopausal status may need to be considered when determining individual risk for breast cancer. PMID:24647890

  15. 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. PMID:27383135

  16. 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

  17. 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.

  18. XPD Asp312Asn polymorphism and esophageal cancer risk: an update meta-analysis based on 3928 cases and 6012 controls

    PubMed Central

    Guo, Xu-Feng; Wang, Jun; Lei, Xiao-Fei; Zeng, Yan-Ping; Lv, Xiao-Guang; Dong, Wei-Guo

    2014-01-01

    Background: Although xeroderma pigmentosum group D (XPD) was reported to be related with esophageal cancer (EC) risk, the results remained inconsistent. The aim of this meta-analysis was to make a more precise estimation of the relationship between XPD Asp312Asn polymorphism and EC risk. Methods: We searched PubMed, Web of Science, Embase, Medline, CNKI and Chinese Biomedical database, covering all publications (up to May, 2014). Statistical analyses were performed with Stata software (version 12.0, USA) and RevMan 5.1 (Copenhagen, 2008). The calculation of odds ratios (ORs) with 95% confidence intervals (CI) was calculated to assess the strength of the association. Results: A total of 15 case-control studies from 13 literatures including 3928 cases and 6012 controls described Asp312Asn genotypes and EC risk. A significant association between XPD Asp312Asn polymorphism and EC risk was found when all the eligible studies were pooled into this meta-analysis. It’s also the same result in subgroup analysis of smokers in dominant model (OR=1.63, 95% CI: 1.06-2.50, P=0.03). However, in the stratified analysis by ethnicity and source of population controls, no association between them was discovered. Conclusion: The XPD Asp312Asn polymorphism was proved to contribute to the risk of EC in this meta-analysis. Data showed that tobacco consumption may increase the susceptibility of EC. PMID:25356096

  19. 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

  20. 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.

  1. 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. PMID:25174313

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

  3. Design of a Classification Scheme for Fiction Based on an Analysis of Actual User-Librarian Communication, and Use of the Scheme for Control of Librarian's Search Strategies.

    ERIC Educational Resources Information Center

    Pejtersen, Annelise Mark

    Because the general alphabetic arrangement of fiction in libraries is of little use to the ordinary reader, whose criteria for selecting books often relates to book content, a multi-dimensional and inexclusive fiction classification scheme was developed as a model for both book description and search strategy. Based on analysis of 160 actual…

  4. 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.

  5. Transputer-based readout controller

    NASA Astrophysics Data System (ADS)

    Belusevic, R.; Nixon, G.

    1989-05-01

    A bus-oriented readout controller is described that uses a transputer both as a direct memory access (DMA) device and a crate processor. It achieves data transfer rates of up to 13 Mbytes/s, yet is very simple in design. Data transfer is reduced to moving arrays within memory, which eliminates the need for bus arbitration and interfacing logic. A trivial extension of the basic design results in a twofold increase in the maximum data transfer speed, to 27 Mbytes/s. A second transputer, added to the crate controller for extra flexibility and processing power, enables it to form part of a second level data acquisition system, with a total of 8 links (maximum link speed 20 Mbits/s) available for intercrate communications. This design was developed for the readout system of the ZEUS Central Tracking Detector.

  6. 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.

  7. A CAMAC based knob controller for the LAMPF control system

    SciTech Connect

    Smith, W.; Bjorklund, E.

    1987-01-01

    The control computer for the Los Alamos Meson Physics Facility (LAMPF) has been recently upgraded from an SEL-840 to a VAX 11/780 running the VMS operating system. As part of this upgrade, a CAMAC-based knob controller was developed for the new control system. The knobs allow the facility operators to have slew control over software selectable accelerator devices. An alphanumeric display associated with each knob monitors the progress of the selected device. This paper describes the system requirements for the new LAMPF knob controller, and the resulting hardware and software design.

  8. 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. PMID:26469912

  9. 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

  10. Platinum-based chemotherapy in triple-negative breast cancer: a systematic review and meta-analysis of randomized-controlled trials.

    PubMed

    Guan, Xiuwen; Ma, Fei; Fan, Ying; Zhu, Wenjie; Hong, Ruoxi; Xu, Binghe

    2015-09-01

    The aim of this study was to evaluate the benefits of the addition of platinum agents for the treatment of patients with triple-negative breast cancer on the basis of randomized-controlled trials (RCTs). A fully recursive literature search was performed in the Cochrane Controlled Trials Register Databases, Medline, EMBASE, and Chinese Biomedical Literature Database in any language. RCTs were considered for inclusion. Eight randomized-controlled trials totaling 1142 patients were included. The objective response rate was reported in six RCTs, which were divided into two subgroups: palliative chemotherapy for a metastatic setting and neoadjuvant chemotherapy. Using the fixed-effects model, the difference between the platinum-based group and the non-platinum-based group was found to be statistically significant in the overall study [relative risk (RR)=1.36, P<0.00001], the subgroup of palliative chemotherapy (RR=2.42, P<0.00001), and the subgroup of neoadjuvant (RR=1.15, P=0.01). Pathological complete response rates were based on five studies, and the results between the platinum-based group and the non-platinum-based group also reached statistical significance both in the fixed-effects model (RR=1.43, P<0.0001) and in the random-effects model (RR=1.47, P=0.01). The results seemed to yield a better response rate and pathological complete response rate for platinum-based therapy in triple-negative breast cancer. However, because of the heterogeneous nature of primary trial outcomes, caution should be exercised in coming to this conclusion and further research is necessary to support these findings. PMID:26086398

  11. 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. PMID:25831054

  12. 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

  13. 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.

  14. Analysis And Control System For Automated Welding

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    Automated variable-polarity plasma arc (VPPA) welding apparatus operates under electronic supervision by welding analysis and control system. System performs all major monitoring and controlling functions. It acquires, analyzes, and displays weld-quality data in real time and adjusts process parameters accordingly. Also records pertinent data for use in post-weld analysis and documentation of quality. System includes optoelectronic sensors and data processors that provide feedback control of welding process.

  15. 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…

  16. The association between the ring finger protein 213 (RNF213) polymorphisms and moyamoya disease susceptibility: a meta-analysis based on case-control studies.

    PubMed

    Sun, Xun-Sha; Wen, Jun; Li, Jiao-Xing; Lai, Rong; Wang, Yu-Fang; Liu, Hui-Jiao; Sheng, Wen-Li

    2016-06-01

    A number of studies assessed the association of ring finger protein 213 (RNF213) gene polymorphisms with moyamoya disease (MMD), but the results were not entirely consistent. This meta-analysis was performed to explore the relationship between RNF213 polymorphisms and moyamoya disease in Asian population. A systematic search from the PubMed, MEDLINE, EMBASE, ISI web of science, CNKI, China CBM and WANFANG DATA databases was conducted to retrieve published studies until March 2015. Statistical analyses were performed using the STATA12.0 software. Fixed or random effects model, subgroup analysis, sensitivity analysis, and publication bias were used to improve the comprehensive analysis. Eight papers including 904 MMD patients and 2258 controls were recruited in the meta-analysis. rs112735431 was closely associated with the risk of MMD among Asian population in all genetic models (dominant model: OR 103.39, 95 % CI 52.25-204.55, P = 1.69e-40; recessive model: OR 16.45, 95 % CI 6.00-45.10, P = 5.33e-08; additive model: OR 61.49, 95 % CI 22.07-171.33, P = 3.32e-15), especially in the Japanese population. Subgroup analysis revealed highly statistically significant higher risk in the patients with family histories. Although another polymorphism rs148731719 showed no significant association with the MMD, rs138130613 was found to be related to the higher risk in Chinese population (dominant model: OR 8.34, 95 % CI 1.72-40.47, P = 0.008). Our meta-analysis strengthens RNF213 rs112735431 is closely associated with the increased risk of MMD in Japanese, and the screening combined with rs112735431 and rs138130613may improve the detection rate for MMD in China. PMID:26847828

  17. 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. PMID:26150675

  18. A comprehensive review of the implementation of hazard analysis critical control point (HACCP) to the production of flour and flour-based products.

    PubMed

    Arvanitoyannis, Ioannis S; Traikou, Athina

    2005-01-01

    The production of flour and semolina and their ensuing products, such as bread, cake, spaghetti, noodles, and corn flakes, is of major importance, because these products constitute some of the main ingredients of the human diet. The Hazard Analysis Critical Control Point (HACCP) system aims at ensuring the safety of these products. HACCP has been implemented within the frame of this study on various products of both Asian and European origin; the hazards, critical control limits (CCLs), observation practices, and corrective actions have been summarized in comprehensive tables. Furthermore, the various production steps, packaging included, were thoroughly analyzed, and reference was made to both the traditional and new methodologies in an attempt to pinpoint the occurring differences (advantages and disadvantages) per process. PMID:16130413

  19. Symptom factor analysis, clinical findings, and functional status in a population-based case control study of Gulf War unexplained illness.

    PubMed

    Bourdette, D N; McCauley, L A; Barkhuizen, A; Johnston, W; Wynn, M; Joos, S K; Storzbach, D; Shuell, T; Sticker, D

    2001-12-01

    Few epidemiological studies have been conducted that have incorporated clinical evaluations of Gulf War veterans with unexplained health symptoms and healthy controls. We conducted a mail survey of 2022 Gulf War veterans residing in the northwest United States and clinical examinations on a subset of 443 responders who seemed to have unexplained health symptoms or were healthy. Few clinical differences were found between cases and controls. The most frequent unexplained symptoms were cognitive/psychological, but significant overlap existed with musculoskeletal and fatigue symptoms. Over half of the veterans with unexplained musculoskeletal pain met the criteria for fibromyalgia, and a significant portion of the veterans with unexplained fatigue met the criteria for chronic fatigue syndrome. Similarities were found in the clinical interpretation of unexplained illness in this population and statistical factor analysis performed by this study group and others. PMID:11765674

  20. 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

  1. 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. PMID:26114745

  2. Modelling spatial anisotropy of gold concentration data using GIS-based interpolated maps and variogram analysis: Implications for structural control of mineralization

    NASA Astrophysics Data System (ADS)

    Samal, Abani R.; Sengupta, Raja R.; Fifarek, Richard H.

    2011-08-01

    Linear trends of anomalously high gold values in the Florida Canyon gold deposit, Nevada have been identified using a combination of contour maps of gold (Au) concentration developed with a geographic information system (GIS) and variogram maps created using a geostatistical analysis package. These linear trends are interpreted to represent major fault zones that exerted a prinicipal control on gold mineralization and therefore imparted a spatial anisotropy to gold concentrations. Oxidation state information such as oxide, sulfide or mixed was used initially to map and contour the lower limit of the oxidation zone. Linear trends on this surface suggest the location and trend of major structural elements in the deposit that guided late oxidizing fluids. Subsequently, four contour maps of gold concentrations in oxidized rocks were produced, each map representing 500 ft vertical intervals starting at 3500 ft above mean sea level (msl). Relatively high concentrations of Au that form linear trends on these maps suggest the presence of structural features, such as shear zones that controlled mineralization. Finally, to validate the observed trends, variogram maps of gold concentrations were derived through geostatistical analysis and the major axes of anisotropy were determined for each map. The results that emerge suggest linear trends of northeast, northwest and, less prominently, north-south orientations. The north-south and northeast trends match those of known and mapped major structures associated with the Florida Canyon deposit. However, the results imply a stronger control on mineralization by northwest-trending structures than previously recognized and the location of possible structures of all trends not previously mapped. They also serve to identify faults that controlled both early hydrothermal fluids and late oxidizing fluids since the gold distribution represents the time integrated effects of both fluid events. The linear trends derived by spatial analysis

  3. IAC control system analysis development

    NASA Technical Reports Server (NTRS)

    Frisch, H. P.

    1982-01-01

    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.

  4. 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…

  5. Lack of association between XPC Lys939Gln polymorphism and prostate cancer risk: an updated meta-analysis based on 3039 cases and 3253 controls

    PubMed Central

    Wu, Haoran; Lv, Zhong; Wang, Xugang; Zhang, Liang; Mo, Naixin

    2015-01-01

    Several studies have evaluated the relationship between xeroderma pigmentosum complementation group C (XPC) variants and prostate cancer (PCa) risk. However, the results remain inconclusive. The objective of this study was to identify the role of XPC Lys939Gln variant on PCa occurrence. Relevant case-control studies published between 2000 and 2014 were retrieved in electronic databases. The pooled odds ratio (ORs) and 95% confidence interval (CI) were employed to calculate the strength of association. Finally, a total of eight articles including 3039 PCa patients and 3203 healthy controls were screened out. Our results found that the frequency of C allele was a little higher in PCa cases than that in control, but it was not associated with the increased risk of PCa (C vs. A: OR=1.05, 95% CI=0.98-1.13, P=0.19). This insignificant association was also observed in other genetic models (P>0.05). In subgroup analysis by ethnicity, no significant relationship was found in any study-population (Asian, Caucasian and African) as well. In conclusions, our results indicated that XPC Lys939Gln polymorphism was not associated with PCa susceptibility. Further large well-designed epidemiologic studies with gene-gene and gene-environment interaction should be included and considered. PMID:26770390

  6. 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.

  7. 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

  8. Market-based control of active surfaces

    NASA Astrophysics Data System (ADS)

    Berlin, Andrew A.; Hogg, Tad; Jackson, Warren B.

    1998-12-01

    This paper describes a market-based approach to controlling a smart matter-based object transport system, in which an array of distributed air jets applies forces to levitate and control the motion of a planar object. In the smart matter regime, the effects of spatial and temporal variation of operating parameters among a multiplicity of sensor, actuators, and controllers make it desirable for a control strategy to exhibit a minimal dependence on system models, and to be able to arbitrate among conflicting goals. A market-based strategy is introduced that aggregates the control requirements of multiple relatively simple local controllers, each of which seeks to optimize the performance of the system within a limited spatial and temporal range. These local controllers act as the market's consumers, and two sets of distributed air jets act as the producers. Experiments are performed comparing the performance of the market-based strategy to a near-optimal model-derived benchmark, as well as to a hand-tuned PD controller. Results indicate that even though the local controllers in the market are not based on a detailed model of the system dynamics, the market is able to effectively approximate the performance of the model-based benchmark. In certain specialized cases, such as tracking a step trajectory, the performance of the market surpasses the performance of the model-based benchmark by balancing the needs of conflicting control goals. A brief overview of the active surface smart matter prototype being developed at Xerox PARC that is the motivation behind this work is also presented.

  9. 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.

  10. Nonlinear Robustness Analysis Tools for Flight Control Law Validation & Verification

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhijit

    Loss of control in flight is among the highest aviation accident categories for both the number of accidents and the number of fatalities. The flight controls community is seeking an improved validation tools for safety critical flight control systems. Current validation tools rely heavily on linear analysis, which ignore the inherent nonlinear nature of the aircraft dynamics and flight control system. Specifically, current practices in validating the flight control system involve gridding the flight envelope and checking various criteria based on linear analysis to ensure safety of the flight control system. The analysis and certification methods currently applied assume the aircrafts' dynamics is linear. In reality, the behavior of the aircraft is always nonlinear due to its aerodynamic characteristics and physical limitations imposed by the actuators. This thesis develops nonlinear analysis tools capable of certifying flight control laws for nonlinear aircraft dynamics. The proposed analysis tools can handle both the aerodynamic nonlinearities and the physical limitations imposed by the actuators in the aircrafts' dynamics. This proposed validation technique will extend and enrich the predictive capability of existing flight control law validation methods to analyze nonlinearities. The objective of this thesis is to provide the flight control community with an advanced set of analysis tools to reduce aviation fatalities and accidents rate.

  11. Attitude control of the space construction base: A modular approach

    NASA Technical Reports Server (NTRS)

    Oconnor, D. A.

    1982-01-01

    A planar model of a space base and one module is considered. For this simplified system, a feedback controller which is compatible with the modular construction method is described. The systems dynamics are decomposed into two parts corresponding to base and module. The information structure of the problem is non-classical in that not all system information is supplied to each controller. The base controller is designed to accommodate structural changes that occur as the module is added and the module controller is designed to regulate its own states and follow commands from the base. Overall stability of the system is checked by Liapunov analysis and controller effectiveness is verified by computer simulation.

  12. 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.

  13. 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.

  14. Manganese Superoxide Dismutase and Breast Cancer Recurrence: A Danish Clinical Registry-Based Case-Control Study, and a Meta-Analysis

    PubMed Central

    Cronin-Fenton, Deirdre P.; Christensen, Mariann; Lash, Timothy L.; Ahern, Thomas P.; Pedersen, Lars; Garne, Jens Peter; Ewertz, Marianne; Autrup, Herman; Sørensen, Henrik T.; Hamilton-Dutoit, Stephen

    2014-01-01

    Background Manganese superoxide dismutase (MnSOD) inhibits oxidative damage and cancer therapy effectiveness. A polymorphism in its encoding gene (SOD2: Val16Ala rs4880) may confer poorer breast cancer survival, but data are inconsistent. We examined the association of SOD2 genotype and breast cancer recurrence (BCR) among patients treated with cyclophosphamide-based chemotherapy (Cyclo). We compared our findings with published studies using meta-analyses. Methods We conducted a population-based case-control study of BCR among women in Jutland, Denmark. Subjects were diagnosed with non-metastatic breast cancer from 1990–2001, received adjuvant Cyclo, and were registered in the Danish Breast Cancer Cooperative Group. We identified 118 patients with BCR and 213 matched breast cancer controls. We genotyped SOD2 and used conditional logistic regression to compute the odds ratio (OR) and associated 95% confidence intervals (95% CI) of BCR. We used random-effects meta-analytic models to evaluate the association of SOD2 polymorphisms and BCR. Results The frequency of the SOD2-Ala allele was 70% in cases versus 71% in controls; 40% versus 44% were heterozygotes, and 30% versus 25% were homozygotes, respectively. Heterozygote and homozygote carriers of the Ala allele had no increased rate of BCR (OR = 1.1, 95%CI = 0.65, 2.0, and OR = 0.87, 95%CI = 0.47, 1.6, respectively). Five studies informed the meta-analytic models; summary estimates associating BCR for homozygote, or any inheritance of the variant Ala allele were 1.18 (95%CI = 0.74, 1.88), and 1.18, (95%CI = 0.91, 1.54), respectively. Conclusion Our findings do not suggest that MnSOD enzymatic activity, as measured by SOD2 genotype, affects rates of BCR among patients treated with Cyclo. PMID:24498107

  15. 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

  16. 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.

  17. Analysis and decoupling control of a permanent magnet spherical actuator.

    PubMed

    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. PMID:24387456

  18. 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.

  19. 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.

  20. 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. PMID:25881841

  1. 2D Wavefront Sensor Analysis and Control

    Energy Science and Technology Software Center (ESTSC)

    1996-02-19

    This software is designed for data acquisition and analysis of two dimensional wavefront sensors. The software includes data acquisition and control functions for an EPIX frame grabber to acquire data from a computer and all the appropriate analysis functions necessary to produce and display intensity and phase information. This software is written in Visual Basic for windows.

  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. Transplantation of Autologous Mesenchymal Stem Cells for End-Stage Liver Cirrhosis: A Meta-Analysis Based on Seven Controlled Trials

    PubMed Central

    Ma, Xiang-Rui; Tang, Ya-Ling; Xuan, Ming; Chang, Zheng; Wang, Xiao-Yi; Liang, Xin-Hua

    2015-01-01

    Background. The bone marrow-derived mesenchymal stem cells (BM-MSCs) have demonstrated great potential as regenerative medicine in different therapeutic applications. This study aims to pool previous controlled clinical trials to make an update assessment of the effectiveness of BM-MSC transplantation on end-stage liver cirrhosis. Methods. Relevant studies published between January 1990 and June 2014 were searched among Pubmed, Embase, and ClinicalTrial.gov. A meta-analysis was performed to assess the effect of BM-MSCs on liver function indicators, including Models of End-Stage Liver Disease (MELD) score, serum albumin (g/L), total bilirubin (mg/dl), Prothrombin concentration (%), and alanine aminotransferase (ALT) (U/L). Results. BM-MSCs therapy could significantly improve liver function in patients with end-stage liver cirrhosis, in terms of MELD score, serum albumin, total bilirubin, and prothrombin concentration, at least during the half year after transplantation. Conclusions. Due to BM-MSCs' immunomodulatory functions and the potential to differentiate into hepatocytes, they are a promising therapeutic agent to liver cirrhosis. Considering currently available evidence, this therapy is relatively safe and effective in improving liver function. However, how different variables should be controlled to optimize the therapeutic effect is still not clear. Thus, future mechanism studies and clinical trials are required for this optimization. PMID:25861263

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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…

  9. 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.

  10. 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.

  11. PDA based control of multiple heterogeneous robots

    NASA Astrophysics Data System (ADS)

    Kim, Tae Geun; Suk, Sung Youn; Park, Jae Suk; Kim, Sung Rock; Jeon, You Ju; Lee, Suk Gyu

    2005-12-01

    This paper proposed PDA based control of multiple heterogeneous robots by sharing information to perform surveillance and reconnaissance. Since heterogeneous groups were equipped with different sensor systems, they in particular allow a potentially greater degree of fault-tolerance compared to homogeneous groups. In this paper, unknown environment around robots was recognized efficiently by multiple robots using internet based PDA, where communication between PDA(user interface) and host PC(a controller for robots) is based on TCP/IP protocol. Each of the robots collects sensor data regarding its own motion and environment to share this information with the rest of he team during he update cycles.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. A hospital-based case-control study of acute myeloid leukemia in Shanghai: analysis of environmental and occupational risk factors by subtypes of the WHO classification.

    PubMed

    Wong, Otto; Harris, Fran; Armstrong, Thomas W; Hua, Fu

    2010-03-19

    The objectives were: (1) to investigate potential environmental and occupational risk factors of acute myeloid leukemia (AML), and (2) to explore the relationships between risk factors and AML subtypes according to the World Health Organization (WHO) classification. The investigation was a hospital-based case-control study consisting of 722 newly diagnosed AML cases (August 2003 through June 2007) and 1444 individually gender-age-matched patient controls at 29 hospitals in Shanghai. A 17-page questionnaire was used to obtain information on demographics, medical history, family history, lifestyle risk factors, employment history, residential history, and occupational and non-occupational exposures. Certain occupations of interest triggered a second questionnaire, which was occupation-specific and asked for more details about jobs, tasks, materials used and work environment. Exposure assessments were based on the questionnaires, on-site workplace investigations, data published in the Chinese literature, historical exposure measurements maintained by government health agencies, and expert opinions of a panel of local scientists who were familiar with workplaces in Shanghai. Risk estimates (odds ratios and 95% confidence intervals) of individual risk factors were calculated using conditional logistic regression models. A number of potential environmental and occupational risk factors were associated with an increased risk of AML (all subtypes combined) and/or individual subtypes; including home or workplace renovation, living on a farm, planting crops, raising livestock or animals, farm workers, metal workers, rubber and plastic workers, wood and furniture workers, printers, loading and unloading workers, automobile manufacturing, general construction, and food and beverage industry (restaurants and other eateries). Exposures associated with an increased risk of AML (all subtypes combined) and/or individual subtypes included benzene, diesel fuel, metals, insecticides

  2. 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.

  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. DNA-based control of protein activity.

    PubMed

    Engelen, W; Janssen, B M G; Merkx, M

    2016-03-01

    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

  5. 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.

  6. Perturbation analysis of optimal integral controls

    NASA Technical Reports Server (NTRS)

    Slater, G. L.

    1984-01-01

    The application of linear optimal control to the design of systems with integral control action on specified outputs is considered. Using integral terms in a quadratic performance index, an asymptotic analysis is used to determine the effect of variable quadratic weights on the eigenvalues and eigenvectors of the closed loop system. It is shown that for small integral terms the placement of integrator poles and gain calculation can be effectively decoupled from placement of the primary system eigenvalues. This technique is applied to the design of integral controls for a STOL aircraft outer loop guidance system.

  7. 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. PMID:27129764

  8. 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.

  9. An interferometer based phase control system

    NASA Technical Reports Server (NTRS)

    Ott, J. H.; Rice, J. S.

    1980-01-01

    An interferometer based phase control system for focusing and pointing the solar power satellite (SPS) power beam is discussed. The system is ground based and closed loop. One receiving antenna is required on Earth. A conventional uplink data channel transmits an 8 bit phase error correction back to the SPS for sequential calibration of each power module. Beam pointing resolution is better than 140 meters at the rectenna.

  10. Interferometer-based phase control system

    SciTech Connect

    Ott, J.H.; Rice, J.S.

    1980-01-01

    An interferometer-based phase control system for focusing and pointing the SPS power beam is discussed. The system is ground based and closed loop. One receiving antenna is required on earth. A conventional uplink data channel transmits an 8-bit phase error correction back to the SPS for sequential calibration of each power module. Beam pointing resolution is better than 140 meters at the Rectenna. 1 ref.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.…

  17. Wavelet-based polarimetry analysis

    NASA Astrophysics Data System (ADS)

    Ezekiel, Soundararajan; Harrity, Kyle; Farag, Waleed; Alford, Mark; Ferris, David; Blasch, Erik

    2014-06-01

    Wavelet transformation has become a cutting edge and promising approach in the field of image and signal processing. A wavelet is a waveform of effectively limited duration that has an average value of zero. Wavelet analysis is done by breaking up the signal into shifted and scaled versions of the original signal. The key advantage of a wavelet is that it is capable of revealing smaller changes, trends, and breakdown points that are not revealed by other techniques such as Fourier analysis. The phenomenon of polarization has been studied for quite some time and is a very useful tool for target detection and tracking. Long Wave Infrared (LWIR) polarization is beneficial for detecting camouflaged objects and is a useful approach when identifying and distinguishing manmade objects from natural clutter. In addition, the Stokes Polarization Parameters, which are calculated from 0°, 45°, 90°, 135° right circular, and left circular intensity measurements, provide spatial orientations of target features and suppress natural features. In this paper, we propose a wavelet-based polarimetry analysis (WPA) method to analyze Long Wave Infrared Polarimetry Imagery to discriminate targets such as dismounts and vehicles from background clutter. These parameters can be used for image thresholding and segmentation. Experimental results show the wavelet-based polarimetry analysis is efficient and can be used in a wide range of applications such as change detection, shape extraction, target recognition, and feature-aided tracking.

  18. 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

  19. Experimental Physics and Industrial Control System BASE

    Energy Science and Technology Software Center (ESTSC)

    2002-08-01

    EPICS is a set of software tools and applications developed initially by the Los Alamos National Laboratories for the control of large accelerators, enhanced by contributions from users worldwide and continuing development for application to other large scientific experimental equipment, such as telescopes and detectors. EPICS consists of EPICS BASE, Extensions, and other unbundled modules. EPICS BASE marks a change in the handling of the distribution of the software starting with the EPICS BASE 3.13.7more » AND 3.140beta2 software.« less

  20. A passivity based controller for free base manipulators

    NASA Technical Reports Server (NTRS)

    Chuang, C.-H.; Mittal, Manoj; Juang, Jer-Nan

    1993-01-01

    A feedback linearization technique is used in conjunction with passivity concepts to design robust controllers for free base robots. It is assumed that bounded modeling uncertainties exist in the inertia matrix and the vector representing the coriolis, centripetal, and friction forces. Under these assumptions, the controller guarantees asymptotic tracking of the joint variables. A Lagrangian approach is used to develop a dynamic model for space robots. Closed-loop simulation results are illustrated for a simple case of a single link planar space manipulator with freely floating base.

  1. Bortezomib-based vs non-bortezomib-based post-transplantation treatment in multiple myeloma patients: a systematic review and meta-analysis of Phase III randomized controlled trials

    PubMed Central

    Liu, Xiaoping; He, Colin K; Meng, Xiangyu; He, Li; Li, Kaili; Liang, Qing; Shao, Liang; Liu, Shangqin

    2015-01-01

    Objective To evaluate the efficacy and safety of bortezomib-based vs non-bortezomib-based post-transplantation therapy in patients with multiple myeloma. Methods Data of relevant randomized controlled trials assessing the effect of bortezomib as post-transplantation consolidation or maintenance therapy was obtained through a comprehensive search. The outcome measures included response rate, progression-free survival, overall survival, and adverse events (AEs). The hazard ratio (HR), Cochran-Mantel-Haenszel odds ratio (OR), and 95% confidence interval (95% CI) were applied to evaluate the effect of bortezomib in relation to the end points such as progression-free survival, overall survival, response rate, and AEs. Results Three randomized controlled trials comprising 1,518 participants were included in this study. Pooled ORs for the rates of overall response, and complete response and near complete response, were 1.85 and 1.75, respectively. Pooled HR for progression-free survival favored bortezomib-based therapy over non-bortezomib-based therapy (0.73, 95% CI: 0.67–0.81), while no statistically significant difference could be found between the two groups regarding the pooled HR for 3-year overall survival. Moreover, incidence rates of overall adverse events and grade 3 and 4 peripheral neuropathy were similar in the bortezomib-based groups and the non-bortezomib-based groups (P=0.12 and P=0.41, respectively). The corresponding cumulative meta-analyses of the rates of overall response rate, complete response and near complete response, and grades 3 and 4 peripheral neuropathy supported the superiority of bortezomib-based maintenance therapy over consolidation therapy. Conclusion Bortezomib-based therapy after autologous stem cell transplantation, with tolerable AEs, could obviously improve the response as well as the outcome of multiple myeloma patients, particularly when bortezomib was administered as maintenance therapy. PMID:26109870

  2. 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

  3. Modeling Controller Tasks for Safety Analysis

    NASA Technical Reports Server (NTRS)

    Brown, Molly; Leveson, Nancy G.

    1998-01-01

    As control systems become more complex, the use of automated control has increased. At the same time, the role of the human operator has changed from primary system controller to supervisor or monitor. Safe design of the human computer interaction becomes more difficult. In this paper, we present a visual task modeling language that can be used by system designers to model human-computer interactions. The visual models can be translated into SpecTRM-RL, a blackbox specification language for modeling the automated portion of the control system. The SpecTRM-RL suite of analysis tools allow the designer to perform formal and informal safety analyses on the task model in isolation or integrated with the rest of the modeled system.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Control analysis for autonomously oscillating biochemical networks.

    PubMed

    Reijenga, Karin A; Westerhoff, Hans V; Kholodenko, Boris N; Snoep, Jacky L

    2002-01-01

    It has hitherto not been possible to analyze the control of oscillatory dynamic cellular processes in other than qualitative ways. The control coefficients, used in metabolic control analyses of steady states, cannot be applied directly to dynamic systems. We here illustrate a way out of this limitation that uses Fourier transforms to convert the time domain into the stationary frequency domain, and then analyses the control of limit cycle oscillations. In addition to the already known summation theorems for frequency and amplitude, we reveal summation theorems that apply to the control of average value, waveform, and phase differences of the oscillations. The approach is made fully operational in an analysis of yeast glycolytic oscillations. It follows an experimental approach, sampling from the model output and using discrete Fourier transforms of this data set. It quantifies the control of various aspects of the oscillations by the external glucose concentration and by various internal molecular processes. We show that the control of various oscillatory properties is distributed over the system enzymes in ways that differ among those properties. The models that are described in this paper can be accessed on http://jjj.biochem.sun.ac.za. PMID:11751299

  11. 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.

  12. 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.

  13. Computer based terrain analysis for operational planning

    SciTech Connect

    Powell, D.R.

    1987-01-01

    Analysis of operational capability is an ongoing task for military commanders. In peacetime, most analysis is conducted via computer based combat simulations, where selected force structures engage in simulated combat to gain insight into specific scenarios. The command and control (C/sup 2/) mechanisms that direct combat forces are often neglected relative to the fidelity of representation of mechanical and physical entities. C/sup 2/ capabilities should include the ability to plan a mission, monitor execution activities, and redirect combat power when appropriate. This paper discusses the development of a computer based approach to mission planning for land warfare. The aspect emphasized is the computation and representation of relevant terrain features in the context of operational planning.

  14. 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.

  15. 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.

  16. FPGA based Smart Wireless MIMO Control System

    NASA Astrophysics Data System (ADS)

    Usman Ali, Syed M.; Hussain, Sajid; Akber Siddiqui, Ali; Arshad, Jawad Ali; Darakhshan, Anjum

    2013-12-01

    In our present work, we have successfully designed, and developed an FPGA based smart wireless MIMO (Multiple Input & Multiple Output) system capable of controlling multiple industrial process parameters such as temperature, pressure, stress and vibration etc. To achieve this task we have used Xilin x Spartan 3E FPGA (Field Programmable Gate Array) instead of conventional microcontrollers. By employing FPGA kit to PC via RF transceivers which has a working range of about 100 meters. The developed smart system is capable of performing the control task assigned to it successfully. We have also provided a provision to our proposed system that can be accessed for monitoring and control through the web and GSM as well. Our proposed system can be equally applied to all the hazardous and rugged industrial environments where a conventional system cannot work effectively.

  17. The microprocessor-based synthesizer controller

    NASA Technical Reports Server (NTRS)

    Wick, M. R.

    1980-01-01

    Implementation and performance of the microprocessor-based controllers and Dana Digiphase Synthesizer (DCO) installed in the Deep Space Network exciter in the 64-meter and 34-meter subnets to support uplink tuning required for the Voyager-Saturn Encounter is discussed. Test data in tests conducted during the production of the controllers verified the design objective for phase control accuracy of 10 to the - 12 power cycles in eight hours during ramping. Tests conducted require a phase error between a theoretical calculated value and the actual phase of no greater than + or - 1 cycle. Tests included (1) a ramp over a period of eight hours using a ramp rate which covers the synthesizer tuning range (40-51 MHz) and (2) a ramp sequence using the maximum rate (+ or kHz/s) over the tuning range.

  18. 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

  19. 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.

  20. Laboratory quality control based on risk management.

    PubMed

    Nichols, James H

    2011-01-01

    Risk management is the systematic application of management policies, procedures, and practices to the tasks of analyzing, evaluating, controlling and monitoring risk (the effect of uncertainty on objectives). Clinical laboratories conduct a number of activities that could be considered risk management including verification of performance of new tests, troubleshooting instrument problems and responding to physician complaints. Development of a quality control plan for a laboratory test requires a process map of the testing process with consideration for weak steps in the preanalytic, analytic and postanalytic phases of testing where there is an increased probability of errors. Control processes that either prevent or improve the detection of errors can be implemented at these weak points in the testing process to enhance the overall quality of the test result. This manuscript is based on a presentation at the 2nd International Symposium on Point of Care Testing held at King Faisal Specialist Hospital in Riyadh, Saudi Arabia on October 12-13, 2010. Risk management principles will be reviewed and progress towards adopting a new Clinical and Laboratory Standards Institute Guideline for developing laboratory quality control plans based on risk management will be discussed. PMID:21623049

  1. 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.

  2. 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.

  3. 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.

  4. Association between glutathione S-transferase P1 Ile (105) Val gene polymorphism and chronic obstructive pulmonary disease: A meta-analysis based on seventeen case–control studies

    PubMed Central

    Yang, Lingjing; Li, Xixia; Tong, Xiang; Fan, Hong

    2015-01-01

    Introduction Previous studies have shown that glutathione S-transferase P1 (GSTP1) was associated with chronic obstructive pulmonary disease (COPD). However, the association between GSTP1 Ile (105) Val gene polymorphism and COPD remains controversial. To drive a more precise estimation, we performed a meta-analysis based on published case–control studies. Methods An electronic search of PubMed, EMBASE, Cochrane library, Web of Science and China Knowledge Resource Integrated (CNKI) Database for papers on GSTP1 Ile (105) Val gene polymorphism and COPD risk was performed. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the homozygote model, heterozygote model, dominant model, recessive model and an additive mode. Statistical heterogeneity, test of publication bias and sensitivity analysis was performed. The software STATA (Version 13.0) was used data analysis. Results Overall, seventeen studies with 1892 cases and 2012 controls were included in this meta-analysis. The GSTP1 Ile (105) Val polymorphism showed pooled odds ratios for the homozygote comparison (OR = 1.501, 95%CI [0.862, 2.614]), heterozygote comparison (OR = 0.924, 95%CI [0.733, 1.165]), dominant model (OR = 1.003, 95%CI [0.756, 1.331]), recessive model (OR = 1.510, 95%CI [0.934, 2.439]), and an additive model (OR = 1.072, 95%CI [0.822, 1.398]). Conclusions In conclusion, the current meta-analysis, based on the most updated information, showed no significant association between GSTP1 Ile (105) Val gene polymorphism and COPD risk in any genetic models. The results of subgroup analysis also showed no significant association between GSTP1 Ile (105) Val gene polymorphism and COPD risk in Asian population and Caucasian population. Further studies involving large populations and careful control with age, sex, ethnicity, and cigarette smoking are greatly needed. PMID:26504746

  5. Region based Brain Computer Interface for a home control application.

    PubMed

    Akman Aydin, Eda; Bay, Omer Faruk; Guler, Inan

    2015-08-01

    Environment control is one of the important challenges for disabled people who suffer from neuromuscular diseases. Brain Computer Interface (BCI) provides a communication channel between the human brain and the environment without requiring any muscular activation. The most important expectation for a home control application is high accuracy and reliable control. Region-based paradigm is a stimulus paradigm based on oddball principle and requires selection of a target at two levels. This paper presents an application of region based paradigm for a smart home control application for people with neuromuscular diseases. In this study, a region based stimulus interface containing 49 commands was designed. Five non-disabled subjects were attended to the experiments. Offline analysis results of the experiments yielded 95% accuracy for five flashes. This result showed that region based paradigm can be used to select commands of a smart home control application with high accuracy in the low number of repetitions successfully. Furthermore, a statistically significant difference was not observed between the level accuracies. PMID:26736451

  6. 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.

  7. Certification-Based Process Analysis

    NASA Technical Reports Server (NTRS)

    Knight, Russell L.

    2013-01-01

    Space mission architects are often challenged with knowing which investment in technology infusion will have the highest return. Certification-based analysis (CBA) gives architects and technologists a means to communicate the risks and advantages of infusing technologies at various points in a process. Various alternatives can be compared, and requirements based on supporting streamlining or automation can be derived and levied on candidate technologies. CBA is a technique for analyzing a process and identifying potential areas of improvement. The process and analysis products are used to communicate between technologists and architects. Process means any of the standard representations of a production flow; in this case, any individual steps leading to products, which feed into other steps, until the final product is produced at the end. This sort of process is common for space mission operations, where a set of goals is reduced eventually to a fully vetted command sequence to be sent to the spacecraft. Fully vetting a product is synonymous with certification. For some types of products, this is referred to as verification and validation, and for others it is referred to as checking. Fundamentally, certification is the step in the process where one insures that a product works as intended, and contains no flaws.

  8. 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.

  9. 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. The former refers to a bottom-up process which regards each datum as a singleton cluster while the latter refers to a top-down process which regards entire data as a cluster. As the collected literatures, it is noted that the divisive clustering is currently overwhelming both in application and research. Although some famous divisive clustering methods are designed and well developed, clustering problems are still far from being solved. The k - means algorithm is the original divisive clustering method which initially assigns some important index values, such as the clustering number and the initial clustering prototype positions, and that could not be reasonable in some certain occasions. More than the initial problem, the k - means algorithm may also falls into local optimum, clusters in a rigid way and is not available for non-Gaussian distribution. One can see that seeking for a good or natural clustering result, in fact, originates from the one's understanding of the concept of clustering. Thus, the confusion or misunderstanding of the definition of clustering always derives some unsatisfied clustering results. One should consider the definition deeply and seriously. This paper demonstrates the nature of clustering, gives the way of understanding clustering, discusses the methodology of designing a clustering algorithm, and proposes a new clustering method based on relation chains among 2D patterns. In

  10. Development of a Novel Disturbance Observer Based Fractional Order PD Controller for a Gun Control System

    PubMed Central

    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. PMID:24616616

  11. Neural Network Based Montioring and Control of Fluidized Bed.

    SciTech Connect

    Bodruzzaman, M.; Essawy, M.A.

    1996-04-01

    The goal of this project was to develop chaos analysis and neural network-based modeling techniques and apply them to the pressure-drop data obtained from the Fluid Bed Combustion (FBC) system (a small scale prototype model) located at the Federal Energy Technology Center (FETC)-Morgantown. The second goal was to develop neural network-based chaos control techniques and provide a suggestive prototype for possible real-time application to the FBC system. The experimental pressure data were collected from a cold FBC experimental set-up at the Morgantown Center. We have performed several analysis on these data in order to unveil their dynamical and chaotic characteristics. The phase-space attractors were constructed from the one dimensional time series data, using the time-delay embedding method, for both normal and abnormal conditions. Several identifying parameters were also computed from these attractors such as the correlation dimension, the Kolmogorov entropy, and the Lyapunov exponents. These chaotic attractor parameters can be used to discriminate between the normal and abnormal operating conditions of the FBC system. It was found that, the abnormal data has higher correlation dimension, larger Kolmogorov entropy and larger positive Lyapunov exponents as compared to the normal data. Chaotic system control using neural network based techniques were also investigated and compared to conventional chaotic system control techniques. Both types of chaotic system control techniques were applied to some typical chaotic systems such as the logistic, the Henon, and the Lorenz systems. A prototype model for real-time implementation of these techniques has been suggested to control the FBC system. These models can be implemented for real-time control in a next phase of the project after obtaining further measurements from the experimental model. After testing the control algorithms developed for the FBC model, the next step is to implement them on hardware and link them to

  12. Realization of fuzzy controller based on complex control

    NASA Astrophysics Data System (ADS)

    Wang, Bing; Luo, Yuwei; Chen, Yan; Zhao, Mingfu; Dong, Yu

    2006-11-01

    At present years, fuzzy control technique has been applied and extended on engineering control. The paper adopts 89C52 single chip (SCM) as the hardware platform and applies fuzzy control strategy and algorithm to realize the design of the fuzzy controller. The controller composed to be a closed-loop real-time control system by computer, A/D, D/A, sensor, executed motor and controlled object. The structure is a double closed-loop control structure. The system is a double closed-loop control system. Inner loop adopts an analog current controller and outer loop adopts a digital controller. The system applied fuzzy control strategy and algorithm. The controller takes Volts D.C. signal, pulse signal, analog feedback current signal as its input and on-off magnetism team motor as its control structure. That is to say, the controller is divided into basic fuzzy control and warp integral control, increases proportional integral, decreases the fluctuation near the zero in order to improve the precision of controller.

  13. Model based control of a rehabilitation robot for lower extremities.

    PubMed

    Xie, Xiao-Liang; Hou, Zeng-Guang; Li, Peng-Feng; Ji, Cheng; Zhang, Feng; Tan, Min; Wang, Hongbo; Hu, Guoqing

    2010-01-01

    This paper mainly focuses on the trajectory tracking control of a lower extremity rehabilitation robot during passive training process of patients. Firstly, a mathematical model of the rehabilitation robot is introduced by using Lagrangian analysis. Then, a model based computed-torque control scheme is designed to control the constrained four-link robot (with patient's foot fixed on robot's end-effector) to track a predefined trajectory. Simulation results are provided to illustrate the effectiveness of the proposed model based computed-torque algorithm. In the simulation, a multi-body dynamics and motion software named ADAMS is used. The combined simulation of ADAMS and MATLAB is able to produce more realistic results of this complex integrated system. PMID:21097222

  14. Model-based needle control in prostate percutaneous procedures.

    PubMed

    Maghsoudi, Arash; Jahed, Mehran

    2013-01-01

    In percutaneous applications, needle insertion into soft tissue is considered as a challenging procedure, and hence, it has been the subject of many recent studies. This study considers a model-based dynamics equation to evaluate the needle movement through prostate soft tissue. The proposed model estimates the applied force to the needle using the tissue deformation data and finite element model of the tissue. To address the role of mechanical properties of the soft tissue, an inverse dynamics control method based on sliding mode approach is used to demonstrate system performance in the presence of uncertainties. Furthermore, to deal with inaccurate estimation of mechanical parameters of the soft tissue, an adaptive controller is developed. Moreover, through a sensitivity analysis, it is shown that the uncertainty in the tissue mechanical parameters affects the system performance. Our results indicate that the adaptive controller approach performs slightly better than inverse dynamics method at the expense of fine-tuning the additional gain parameter. PMID:23516956

  15. Development of ADOCS controllers and control laws. Volume 2: Literature review and preliminary analysis

    NASA Technical Reports Server (NTRS)

    Landis, Kenneth H.; Glusman, Steven I.

    1985-01-01

    The Advanced Cockpit Controls/Advanced Flight Control System (ACC/AFCS) study was conducted by the Boeing Vertol Company as part of the Army's Advanced Digital/Optical Control System (ADOCS) program. Specifically, the ACC/AFCS investigation was aimed at developing the flight control laws for the ADOCS demonstrator aircraft which will provide satisfactory handling qualities for an attack helicopter mission. The three major elements of design considered are as follows: Pilot's integrated Side-Stick Controller (SSC) -- Number of axes controlled; force/displacement characteristics; ergonomic design. Stability and Control Augmentation System (SCAS)--Digital flight control laws for the various mission phases; SCAS mode switching logic. Pilot's Displays--For night/adverse weather conditions, the dynamics of the superimposed symbology presented to the pilot in a format similar to the Advanced Attack Helicopter (AAH) Pilot Night Vision System (PNVS) for each mission phase as a function of ACAS characteristics; display mode switching logic. Findings from the literature review and the analysis and synthesis of desired control laws are reported in Volume 2. Conclusions drawn from pilot rating data and commentary were used to formulate recommendations for the ADOCS demonstrator flight control system design. The ACC/AFCS simulation data also provide an extensive data base to aid the development of advanced flight control system design for future V/STOL aircraft.

  16. Infrared Sensor-Based Temperature Control for Domestic Induction Cooktops

    PubMed Central

    Lasobras, Javier; Alonso, Rafael; Carretero, Claudio; Carretero, Enrique; Imaz, Eduardo

    2014-01-01

    In this paper, a precise real-time temperature control system based on infrared (IR) thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented. PMID:24638125

  17. Image-based control of skin melanin texture

    NASA Astrophysics Data System (ADS)

    Tsumura, Norimichi; Nakaguchi, Toshiya; Ojima, Nobutoshi; Takase, Koichi; Okaguchi, Saya; Hori, Kimihiko; Miyake, Yoichi

    2006-09-01

    We introduce a useful tool for controlling the skin melanin texture of facial photographs. Controlling the skin melanin texture is an important task in the reproduction of posters, TV commercials, movies, and so on. We used component maps of melanin, which were obtained by a previous method [J. Opt. Soc. Am. A 16, 2169 (1999)] as the first processing step. We propose to control the melanin texture continuously and physiologically, based on the analysis of 123 skin textures in our database. The physiological validity for the change of the melanin texture is confirmed by comparing the synthesized image with an ultraviolet image, which can be used to predict the change of melanin texture due to aging. The control processes are implemented on programmable graphics hardware, and real-time processing is achieved for a facial videostream.

  18. Extruder analysis, modeling, and dynamic matrix control

    SciTech Connect

    Sribuangam, D.

    1991-01-01

    The Modern Plastics extruder of the Material Science and Engineering Department is used to extrude high density polyethylene (Alathon 7040). Diameter sensor characterization is done due to the fiber positioning sensitivity of the sensor (Zimmer) and observed variations in the sensor signal. Detailed step test transfer function models are developed where the input variables are take-up speed, screw speed, gear pump speed, and die temperature set point. The output variables are die temperature, die pressure, end of the barrel temperature and pressure. A total of 18 transfer functions are obtained. The relationships between known periodic input variations and the output variations are analyzed by the power spectrum analysis. Due to the dominance of the draw resonance-like variation, the main control objective is to eliminate this variation. Results show that all control methods can handle set point tracking but achieve only a limited reduction in amplitude of the fiber diameter variation.

  19. A quantitative analysis of the F18 flight control system

    NASA Technical Reports Server (NTRS)

    Doyle, Stacy A.; Dugan, Joanne B.; Patterson-Hine, Ann

    1993-01-01

    This paper presents an informal quantitative analysis of the F18 flight control system (FCS). The analysis technique combines a coverage model with a fault tree model. To demonstrate the method's extensive capabilities, we replace the fault tree with a digraph model of the F18 FCS, the only model available to us. The substitution shows that while digraphs have primarily been used for qualitative analysis, they can also be used for quantitative analysis. Based on our assumptions and the particular failure rates assigned to the F18 FCS components, we show that coverage does have a significant effect on the system's reliability and thus it is important to include coverage in the reliability analysis.

  20. Applied behavior analysis and statistical process control?

    PubMed Central

    Hopkins, B L

    1995-01-01

    This paper examines Pfadt and Wheeler's (1995) suggestions that the methods of statistical process control (SPC) be incorporated into applied behavior analysis. The research strategies of SPC are examined and compared to those of applied behavior analysis. I argue that the statistical methods that are a part of SPC would likely reduce applied behavior analysts' intimate contacts with the problems with which they deal and would, therefore, likely yield poor treatment and research decisions. Examples of these kinds of results and decisions are drawn from the cases and data Pfadt and Wheeler present. This paper also describes and clarifies many common misconceptions about SPC, including W. Edwards Deming's involvement in its development, its relationship to total quality management, and its confusion with various other methods designed to detect sources of unwanted variability. PMID:7592156

  1. Overview of systems analysis, market assessment and controls work

    NASA Astrophysics Data System (ADS)

    Warren, M. L.

    1981-08-01

    Heat pump analysis, absorption and Rankine cooling analysis, and desiccant cooling analysis are reported. National energy savings, meeting cost and performance goals, recent simulation analysis, and controls research are discussed.

  2. Association between MTHFR polymorphisms and congenital heart disease: a meta-analysis based on 9,329 cases and 15,076 controls.

    PubMed

    Xuan, Chao; Li, Hui; Zhao, Jin-Xia; Wang, Hong-Wei; Wang, Yi; Ning, Chun-Ping; Liu, Zhen; Zhang, Bei-Bei; He, Guo-Wei; Lun, Li-Min

    2014-01-01

    The aim of our study was to evaluate the association between polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the risk for congenital heart disease (CHD). Electronic literature databases were searched to identify eligible studies published before Jun, 2014. The association was assessed by the odds ratio (OR) with a 95% confidence interval (CI). The publication bias was explored using Begg's test. Sensitivity analysis was performed to evaluate the stability of the crude results. A total of 35 studies were included in this meta-analysis. For the MTHFR C677T polymorphism, we detected significant association in all genetic models for Asian children and the maternal population. Significant association was also detected in T vs. C for a Caucasian paediatric population (OR = 1.163, 95% CI: 1.008-1.342) and in both T vs. C (OR = 1.125, 95% CI: 1.043-1.214) and the dominant model (OR = 1.216, 95% CI:b1.096-1.348) for a Caucasian maternal population. For the MTHFR A1298C polymorphism, the association was detected in CC vs. AC for the Caucasian paediatric population (OR = 1.484, 95% CI: 1.035-2.128). Our results support the MTHFR -677T allele as a susceptibility factor for CHD in the Asian maternal population and the -1298 C allele as a risk factor in the Caucasian paediatric population. PMID:25472587

  3. Inverse kinematic-based robot control

    NASA Technical Reports Server (NTRS)

    Wolovich, W. A.; Flueckiger, K. F.

    1987-01-01

    A fundamental problem which must be resolved in virtually all non-trivial robotic operations is the well-known inverse kinematic question. More specifically, most of the tasks which robots are called upon to perform are specified in Cartesian (x,y,z) space, such as simple tracking along one or more straight line paths or following a specified surfacer with compliant force sensors and/or visual feedback. In all cases, control is actually implemented through coordinated motion of the various links which comprise the manipulator; i.e., in link space. As a consequence, the control computer of every sophisticated anthropomorphic robot must contain provisions for solving the inverse kinematic problem which, in the case of simple, non-redundant position control, involves the determination of the first three link angles, theta sub 1, theta sub 2, and theta sub 3, which produce a desired wrist origin position P sub xw, P sub yw, and P sub zw at the end of link 3 relative to some fixed base frame. Researchers outline a new inverse kinematic solution and demonstrate its potential via some recent computer simulations. They also compare it to current inverse kinematic methods and outline some of the remaining problems which will be addressed in order to render it fully operational. Also discussed are a number of practical consequences of this technique beyond its obvious use in solving the inverse kinematic question.

  4. Transputer based control system for MTLRS

    NASA Technical Reports Server (NTRS)

    Vermaat, Erik; Offierski, Jacek W.; Otten, Klaus H.; Beek, Wiard; Vanes, C.; Sperber, Peter

    1993-01-01

    The Modular Transportable Laser Ranging Systems (MTLRS-1 and MTLRS-2) have been designed in the early eighties and have been in operation very successfully since 1984. The original design of the electronic control system was based on the philosophy of parallel processing, but these ideas could at that time only be implemented to a very limited extent. This present system utilizes two MOTOROLA 6800 8-bit processors slaved to a HP A-600 micro-computer. These processors support the telescope tracking system and the data-acquisition/formatting, respectively. Nevertheless, the overall design still is largely hardware oriented. Because the system is now some nine years old, aging of components increases the risk of malfunctioning and some components or units are outdated and not available anymore. The control system for MTLRS is now being re-designed completely, based on the original philosophy of parallel processing, making use of contemporary advanced electronics and processor technology. The new design aims at the requirements for Satellite Laser Ranging (SLR) in the nineties, making use of the extensive operational experience obtained with the two transportable systems.

  5. An analysis method for control reconfigurability of linear systems

    NASA Astrophysics Data System (ADS)

    Wang, Dayi; Duan, Wenjie; Liu, Chengrui

    2016-01-01

    The reconfigurability of control systems is further researched based on the function-objective model (FOM). The establishment of the FOM has been published in the authors' former paper, solving the problem whether the system is reconfigurable without losing the desired control objective. Based on the FOM, the importance factor, the risk factor and the k th reconfigurability factor are proposed to evaluate the fault risks of all components and the system reconfigurability with k faults. These factors show which components should be improved and which faults cannot be tolerated. The analysis results are very useful for enhancing the fault-tolerance performances of the control systems by improving system designs. A satellite model is utilized to illustrate the proposed method.

  6. Decentralized, cooperative control of multivehicle systems: Design and stability analysis

    NASA Astrophysics Data System (ADS)

    Weitz, Lesley Anne

    2009-12-01

    This dissertation addresses the design and stability analysis of decentralized, cooperative control laws for multivehicle systems. Advances in communication, navigation, and surveillance systems have enabled greater autonomy in multivehicle systems, and there is a shift toward decentralized, cooperative systems for computational efficiency and robustness. In a decentralized control scheme, control inputs are determined onboard each vehicle; therefore, decentralized controllers are more efficient for large numbers of vehicles, and the system is more robust to communication failures and reconfiguration. The design of decentralized, cooperative control laws is explored for a nonlinear vehicle model that can be represented in a double-integrator form. Cooperative controllers are functions of spacing errors with respect to other vehicles in the system, where the communication structure defines the information that is available to each vehicle. Control inputs are selected to achieve internal stability, or zero steady-state spacing errors, between vehicles in the system. Closed-loop equations of motion for the cooperative system can be written in a structural form, where damping and stiffness matrices contain control gains acting on the velocity and positions of the vehicles, respectively. The form of the stiffness matrix is determined by the communication structure, where different communication structures yield different control forms. Communication structures are compared using two structural analysis tools: modal cost and frequency-response functions, which evaluate the response of the multivehicle systems to disturbances. The frequency-response information is shown to reveal the string stability of different cooperative control forms. The effects of time delays in the feedback states of the cooperative control laws on system stability are also investigated. Closed-loop equations of motion are modeled as delay differential equations, and two stability notions are

  7. Cetuximab-based therapy is effective in chemotherapy-naïve patients with advanced and metastatic non-small-cell lung cancer: a meta-analysis of randomized controlled trials.

    PubMed

    Ibrahim, Ezzeldin M; Abouelkhair, Khaled M; Al-Masri, Osama A; Chaudry, Najeeb C; Kazkaz, Ghieth A

    2011-06-01

    Randomized controlled trails (RCTs) where cetuximab added to first-line platinum-based chemotherapy for patients with advanced/metastatic non-small-cell lung cancer (NSCLC) have yielded conflicting results. This meta-analysis intended to evaluate the efficacy and safety of cetuximab-based therapy (CBT) in that setting. We analyzed four eligible RCTs that included 1,003 and 1,015 patients randomized to CBT and control intervention, respectively. As compared with the noncetuximab group, CBT demonstrated an 9% reduction in the risk of disease progression [hazard ratio (HR) = 0.91; (CI = 0.83-1.00); p = 0.06], a 13% reduction in the risk of death [HR = 0.87; (CI = 0.78-0.96); p = 0.005], and an approximately 50% increase in objective response rate [odds ratio (OR) = 1.48; (CI = 1.22-1.80); p < 0.0001]. CBT-related adverse events were similar across comparisons except for toxicities known to be associated with anti-EGFR therapy. CBT produced significant clinical benefit with acceptable toxicity as a first-line strategy in patients with advanced/metastatic NSCLC. Further research is needed to identify markers predictive of cetuximab benefit in that disease. PMID:21424607

  8. Crew Exploration Vehicle Launch Abort Controller Performance Analysis

    NASA Technical Reports Server (NTRS)

    Sparks, Dean W., Jr.; Raney, David L.

    2007-01-01

    This paper covers the simulation and evaluation of a controller design for the Crew Module (CM) Launch Abort System (LAS), to measure its ability to meet the abort performance requirements. The controller used in this study is a hybrid design, including features developed by the Government and the Contractor. Testing is done using two separate 6-degree-of-freedom (DOF) computer simulation implementations of the LAS/CM throughout the ascent trajectory: 1) executing a series of abort simulations along a nominal trajectory for the nominal LAS/CM system; and 2) using a series of Monte Carlo runs with perturbed initial flight conditions and perturbed system parameters. The performance of the controller is evaluated against a set of criteria, which is based upon the current functional requirements of the LAS. Preliminary analysis indicates that the performance of the present controller meets (with the exception of a few cases) the evaluation criteria mentioned above.

  9. Probabilistic constrained load flow based on sensitivity analysis

    SciTech Connect

    Karakatsanis, T.S.; Hatziargyriou, N.D. )

    1994-11-01

    This paper presents a method for network constrained setting of control variables based on probabilistic load flow analysis. The method determines operating constraint violations for a whole planning period together with the probability of each violation. An iterative algorithm is subsequently employed providing adjustments of the control variables based on sensitivity analysis of the constrained variables with respect to the control variables. The method is applied to the IEEE 14 busbar system and to a realistic model of the Hellenic Interconnected system indicating its suitability for short-term operational planning applications.

  10. Application of DNA-based forensic analysis for the detection of homologous transfusion of whole blood and of red blood cell concentrates in doping control.

    PubMed

    Stampella, Alessandra; Di Marco, Sabrina; Pirri, Daniela; de la Torre, Xavier; Botrè, Francesco; Donati, Francesco

    2016-08-01

    In this work we present the application of a method for the identification of homologous blood transfusions using forensic genetic techniques based on DNA typing. Ex vivo mixtures of human blood samples - either whole blood or red blood cell concentrates - simulating homologous blood transfusions at different percentages of the donor were typed for a panel of 16 highly variable DNA short tandem repeats (STR). Tested samples included also mixtures, which gave false-negative results if assayed by the reference flow cytofluorimetric method, which is based on the recognition of target antigens located on the membrane of the red blood cell. The recognition of triplets and quadruplets at various loci gave information of the presence of cells belonging to different individuals, as it is the case for homologous blood transfusions. Specificity and sensitivity of the method were assessed in the validation study. The method proved to be unequivocally specific since it was able to recognize all single profiles of each individual, clearly discriminating them from mixtures. Sensitivity resulted as a consequence of the percentage of the donor aliquot in the total volume of the mixture. Although the source of DNA in a blood sample is represented only by nucleated white blood cells, the same procedure resulted effective also in detecting mixtures of red blood cell concentrates (RBCC) from leukodepletion procedure: DNA of the donor from the residual white blood cells resulted still detectable, even if with an expected loss of sensitivity. The proposed approach may contribute to reduce the risk of false-negative results, which may occur using the reference cytofluorimetric method. PMID:27175858

  11. Analysis of Effectiveness of Phoenix Entry Reaction Control System

    NASA Technical Reports Server (NTRS)

    Dyakonov, Artem A.; Glass, Christopher E.; Desai, Prasun, N.; VanNorman, John W.

    2008-01-01

    Interaction between the external flowfield and the reaction control system (RCS) thruster plumes of the Phoenix capsule during entry has been investigated. The analysis covered rarefied, transitional, hypersonic and supersonic flight regimes. Performance of pitch, yaw and roll control authority channels was evaluated, with specific emphasis on the yaw channel due to its low nominal yaw control authority. Because Phoenix had already been constructed and its RCS could not be modified before flight, an assessment of RCS efficacy along the trajectory was needed to determine possible issues and to make necessary software changes. Effectiveness of the system at various regimes was evaluated using a hybrid DSMC-CFD technique, based on DSMC Analysis Code (DAC) code and General Aerodynamic Simulation Program (GASP), the LAURA (Langley Aerothermal Upwind Relaxation Algorithm) code, and the FUN3D (Fully Unstructured 3D) code. Results of the analysis at hypersonic and supersonic conditions suggest a significant aero-RCS interference which reduced the efficacy of the thrusters and could likely produce control reversal. Very little aero-RCS interference was predicted in rarefied and transitional regimes. A recommendation was made to the project to widen controller system deadbands to minimize (if not eliminate) the use of RCS thrusters through hypersonic and supersonic flight regimes, where their performance would be uncertain.

  12. MAP Attitude Control System Design and Analysis

    NASA Technical Reports Server (NTRS)

    Andrews, S. F.; Campbell, C. E.; Ericsson-Jackson, A. J.; Markley, F. L.; ODonnell, J. R., Jr.

    1997-01-01

    The Microwave Anisotropy Probe (MAP) is a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE) spacecraft. The MAP spacecraft will perform its mission in a Lissajous orbit around the Earth-Sun L(sub 2) Lagrange point to suppress potential instrument disturbances. To make a full-sky map of cosmic microwave background fluctuations, a combination fast spin and slow precession motion will be used. MAP requires a propulsion system to reach L(sub 2), to unload system momentum, and to perform stationkeeping maneuvers once at L(sub 2). A minimum hardware, power and thermal safe control mode must also be provided. Sufficient attitude knowledge must be provided to yield instrument pointing to a standard deviation of 1.8 arc-minutes. The short development time and tight budgets require a new way of designing, simulating, and analyzing the Attitude Control System (ACS). This paper presents the design and analysis of the control system to meet these requirements.

  13. Mindfulness-based stress reduction (MBSR) as sole intervention for non-somatisation chronic non-cancer pain (CNCP): protocol for a systematic review and meta-analysis of randomised controlled trials

    PubMed Central

    Leung, Lawrence; Han, Han; Martin, Mary

    2015-01-01

    Introduction Chronic non-cancer pain (CNCP) affects up to 50% of the world's population. It impacts negatively on quality of life; entailing high costs on our medical systems, and translates to economic burden due to work loss. Aetiology of CNCP is complex and multifactorial, embracing the somatosensory, cognitive and affective domains. Opioid analgesia and other invasive interventions are often inadequate for clinical management of CNCP. Recently, mindfulness-based stress reduction (MBSR) has become a popular therapy for various medical conditions, including CNCP. However, studies reported varying efficacies, and relevant systematic reviews have included clinical trials with inherent heterogeneity either in study conditions or types of interventions used. Our study aims to provide an updated and more critical evaluation of the efficacy of MBSR as the intervention for non-somatisation CNCP. Methods and analysis A systematic review with meta-analysis of randomised controlled trials published in English will be performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines and the Cochrane Collaboration format. MEDLINE, EMBASE, PsychINFO, and the Cochrane Central Register of Controlled Trials Intervention, will be searched independently by reviewers using defined MeSH terms. Studies with full texts using MBSR as the main intervention on patients with non-somatising CNCP will be included. Outcome measures include pain scores and disability assessment scales. Continuous data will be meta-analysed using the RevMan 5 Review Manager programme. Primary analysis will adopt the random effects model in view of heterogeneity between trials. The standardised mean difference will be expressed as the effect size with 95% CIs. Forest plots, funnel plots, the I2 statistic and the Cochrane Risks of Bias Assessment table will be included. Ethics and dissemination No ethics approval is deemed necessary. Results of this study

  14. Cyclic Pursuit Based Formation Control for Cooperative Target-enclosing

    NASA Astrophysics Data System (ADS)

    Hara, Shinji; Hori, Yutaka; Kim, Tae-Hyoung

    This paper studies a formation stability analysis scheme of a distributed cooperative control for target-enclosing operations by multiple homogeneous dynamic agents. To this end, we first present an on-line path generator design method based on a cyclic pursuit scheme. Then, we provide the stability condition which the developed path generator should satisfy. This condition is derived based on a simple stability analysis method for hierarchical large-scale linear systems with a generalized frequency variable. The formation control scheme combined with a cyclic pursuit based distributed on-line path generator satisfying the derived stability condition guarantees the required global convergence property with theoretical rigor. Further, in order to show its distinctive features clearly, we present how to analyze global formation stability for a class of multi-agent systems where each agent is modeled as a second-order system and is locally stabilized by the PID controller. A simulation example illustrates distinctive features of the proposed method and the achievement of a desired pursuit pattern.

  15. Active vibration control based on piezoelectric smart composite

    NASA Astrophysics Data System (ADS)

    Gao, Le; Lu, Qingqing; Fei, Fan; Liu, Liwu; Liu, Yanju; Leng, Jinsong

    2013-12-01

    An aircraft’s vertical fin may experience dramatic buffet loads in high angle of attack flight conditions, and these buffet loads would cause huge vibration and dynamic stress on the vertical fin structure. To reduce the dynamic vibration of the vertical fin structure, macro fiber composite (MFC) actuators were used in this paper. The drive moment equations and sensing voltage equations of the MFC actuators were developed. Finite element analysis models based on three kinds of models of simplified vertical fin structures with surface-bonded MFC actuators were established in ABAQUS. The equivalent damping ratio of the structure was employed in finite element analysis, in order to measure the effectiveness of vibration control. Further, an open-loop test for the active vibration control system of the vertical fin with MFC actuators was designed and developed. The experimental results validated the effectiveness of the MFC actuators as well as the developed methodology.

  16. Cost-effectiveness and cost-benefit analysis of BMPs in controlling agricultural nonpoint source pollution in China based on the SWAT model.

    PubMed

    Liu, Ruimin; Zhang, Peipei; Wang, Xiujuan; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

    2014-12-01

    Best management practices (BMPs) have been widely used in managing agricultural nonpoint source pollution (ANSP) at the watershed level. Most BMPs are related to land use, tillage management, and fertilizer levels. In total, seven BMP scenarios (Reforest1, Reforest2, No Tillage, Contour tillage, and fertilizer level 1-4) that are related to these three factors were estimated in this study. The objectives were to investigate the effectiveness and cost-benefit of these BMPs on ANSP reduction in a large tributary of the Three Gorges Reservoir (TGR) in China, which are based on the simulation results of the Soil and Water Assessment Tool (SWAT) model. The results indicated that reforestation was the most economically efficient of all BMPs, and its net benefits were up to CNY 4.36×10(7) years(-1) (about USD 7.08×10(6) years(-1)). Regarding tillage practices, no tillage practice was more environmentally friendly than other tillage practices, and contour tillage was more economically efficient. Reducing the local fertilizer level to 0.8-fold less than that of 2010 can yield a satisfactory environmental and economic efficiency. Reforestation and fertilizer management were more effective in reducing total phosphorus (TP), whereas tillage management was more effective in reducing total nitrogen (TN). When CNY 10,000 (about USD 162) was applied to reforestation, no tillage, contour tillage, and an 0.8-fold reduction in the fertilizer level, then annual TN load can be reduced by 0.08, 0.16, 0.11, and 0.04 t and annual TP load can be reduced by 0.04, 0.02, 0.01 and 0.03 t, respectively. The cost-benefit (CB) ratios of the BMPs were as follows: reforestation (207 %) > contour tillage (129 %) > no tillage (114 %) > fertilizer management (96 and 89 %). The most economical and effective BMPs can be designated as follows: BMP1 (returning arable land with slopes greater than 25° to forests and those lands with slopes of 15-25° to orchards), BMP2 (implementing no tillage

  17. Toner display based on particle control technologies

    NASA Astrophysics Data System (ADS)

    Kitamura, Takashi

    2011-03-01

    Toner Display is based on an electrical movement of charged particles. Two types of black toner and white particles charged in the different electric polarity are enclosed between two electrodes. The particle movement is controlled by the external electric field applied between two transparent electrodes. The toner is collected to the electrode by an electrostatic force across the insulating layer to display a black image. The toners can be put back to the counter electrode by applying a reverse electric field, and white solid image is displayed. We have studied on the movement of three color particles independently to display color image in Toner Display. Two positively charged color particles with different amount of charge to mass ratio and negatively charged white particles were enclosed in the toner display cell. Yellow, cyan and white images were displayed by an application of voltage.

  18. Hydrophilic membrane-based humidity control.

    PubMed

    Scovazzo, P; Burgos, J; Hoehn, A; Todd, P

    1998-10-14

    A dehumidification system for low gravity plant growth experiments requires the generation of no free-liquid condensate and the recovery of water for reuse. In the systems discussed in this paper, the membrane is a barrier between the humid air phase and a liquid-coolant water phase. The coolant water temperature combined with a transmembrane pressure differential establishes a water flux from the humid air into the coolant water. Building on the work of others, we directly compared different hydrophilic membranes for humidity control. In a direct comparison of the hydrophilic membranes, hollow fiber cellulose ester membranes were superior to metal and ceramic membranes in the categories of condensation flux per surface area, ease of start-up, and stability. However, cellulose ester membranes were inferior to metal membranes in one significant category, durability. Dehumidification systems using mixed cellulose ester membranes failed after operational times of only hours to days. We propose that the ratio of fluid surface area to membrane material area (approximately = membrane porosity) controls the relative performances among membranes. In addition, we clarified design equations for operational parameters such as the transmembrane pressure differential. This technology has several potential benefits related to earth environmental issues including the minimization of airborne pathogen release and higher energy efficiency in air conditioning equipment. Utilizing these study results, we designed, constructed, and flew on the space shuttle missions a membrane-based dehumidification system for a plant growth chamber. PMID:11543067

  19. Simulation-based biagnostics and control for nuclar power plants

    SciTech Connect

    Lee, J.C.

    1993-01-01

    Advanced simulation-based diagnostics and control guidance systems for the identification and management of off-normal transient events in nuclear power plants is currently under investigation. To date a great deal of progress has been made in effectively and efficiently combining information obtained through fuzzy pattern recognition and macroscopic mass and energy inventory analysis for use in multiple failure diagnostics. Work has also begun on the unique problem of diagnostics and surveillance methodologies for advanced passively-safe reactors systems utilizing both statistical and fuzzy information. Plans are also being formulated for the development of deterministic optimal control algorithms combined with Monte Carlo incremental learning algorithms to be used for the flexible and efficient control of reactor transients.

  20. Controlled ecological life support system: Transportation analysis

    NASA Technical Reports Server (NTRS)

    Gustan, E.; Vinopal, T.

    1982-01-01

    This report discusses a study utilizing a systems analysis approach to determine which NASA missions would benefit from controlled ecological life support system (CELSS) technology. The study focuses on manned missions selected from NASA planning forecasts covering the next half century. Comparison of various life support scenarios for the selected missions and characteristics of projected transportation systems provided data for cost evaluations. This approach identified missions that derived benefits from a CELSS, showed the magnitude of the potential cost savings, and indicated which system or combination of systems would apply. This report outlines the analytical approach used in the evaluation, describes the missions and systems considered, and sets forth the benefits derived from CELSS when applicable.

  1. The Effectiveness of Group-based Self-management Programmes to Improve Physical and Psychological Outcomes in Patients with Cancer: a Systematic Review and Meta-analysis of Randomised Controlled Trials.

    PubMed

    Smith-Turchyn, J; Morgan, A; Richardson, J

    2016-05-01

    The purpose of this study was to determine if patients with cancer who participate in group-based self-management programmes have better physical and psychological outcomes than patients with cancer who do not participate in group-based self-management programmes. A literature search was conducted in Ovid MEDLINE, Embase, PsycINFO, CINAHL, CENTRAL, Web of Science and ProQUEST using the terms 'self-management' OR 'self-care' AND 'cancer' OR 'neoplasm'. Randomised controlled trials comparing outcomes for people with cancer participating in group-based self-management programmes with those not participating in these programmes were selected after screening by two reviewers. Initial searches yielded 563 articles. Two reviewers independently extracted data using piloted forms and assessed risk of bias using Cochrane's tool. Standard mean differences were calculated for continuous outcomes. The percentage of variability due to heterogeneity was assessed using I(2). A subgroup analysis was carried out where possible. Six trials were included in the review after 141 full-text articles were screened. Group-based self-management programmes were found to improve physical function [standard mean difference (95% confidence interval) = 0.34 (0.02, 0.65), P = 0.04]. No significant results were found between groups for quality of life [0.48 (-0.16, 1.11), P = 0.14] and physical activity level [0.21 (-0.07, 0.5), P = 0.15] outcomes. Group-based self-management programmes for individuals with cancer resulted in improvements in physical outcomes. However, considerable heterogeneity was found between the included studies and the quality of evidence was very low for all main outcomes. Therefore the results should be viewed with caution. PMID:26522169

  2. An informal analysis of flight control tasks

    NASA Technical Reports Server (NTRS)

    Andersen, George J.

    1991-01-01

    Issues important in rotorcraft flight control are discussed. A perceptual description is suggested of what is believed to be the major issues in flight control. When the task is considered of a pilot controlling a helicopter in flight, the task is decomposed in several subtasks. These subtasks include: (1) the control of altitude, (2) the control of speed, (3) the control of heading, (4) the control of orientation, (5) the control of flight over obstacles, and (6) the control of flight to specified positions in the world. The first four subtasks can be considered to be primary control tasks as they are not dependent on any other subtasks. However, the latter two subtasks can be considered hierarchical tasks as they are dependent on other subtasks. For example, the task of flight control over obstacles can be decomposed as a task requiring the control of speed, altitude, and heading. Thus, incorrect control of altitude should result in poor control of flight over an obstacle.

  3. A Proof of Concept Study of Function-Based Statistical Analysis of fNIRS Data: Syntax Comprehension in Children with Specific Language Impairment Compared to Typically-Developing Controls.

    PubMed

    Fu, Guifang; Wan, Nicholas J A; Baker, Joseph M; Montgomery, James W; Evans, Julia L; Gillam, Ronald B

    2016-01-01

    Functional near infrared spectroscopy (fNIRS) is a neuroimaging technology that enables investigators to indirectly monitor brain activity in vivo through relative changes in the concentration of oxygenated and deoxygenated hemoglobin. One of the key features of fNIRS is its superior temporal resolution, with dense measurements over very short periods of time (100 ms increments). Unfortunately, most statistical analysis approaches in the existing literature have not fully utilized the high temporal resolution of fNIRS. For example, many analysis procedures are based on linearity assumptions that only extract partial information, thereby neglecting the overall dynamic trends in fNIRS trajectories. The main goal of this article is to assess the ability of a functional data analysis (FDA) approach for detecting significant differences in hemodynamic responses recorded by fNIRS. Children with and without SLI wore two, 3 × 5 fNIRS caps situated over the bilateral parasylvian areas as they completed a language comprehension task. FDA was used to decompose the high dimensional hemodynamic curves into the mean function and a few eigenfunctions to represent the overall trend and variation structures over time. Compared to the most popular GLM, we did not assume any parametric structure and let the data speak for itself. This analysis identified significant differences between the case and control groups in the oxygenated hemodynamic mean trends in the bilateral inferior frontal and left inferior posterior parietal brain regions. We also detected significant group differences in the deoxygenated hemodynamic mean trends in the right inferior posterior parietal cortex and left temporal parietal junction. These findings, using dramatically different approaches, experimental designs, data sets, and foci, were consistent with several other reports, confirming group differences in the importance of these two areas for syntax comprehension. The proposed FDA was consistent with the

  4. A Proof of Concept Study of Function-Based Statistical Analysis of fNIRS Data: Syntax Comprehension in Children with Specific Language Impairment Compared to Typically-Developing Controls

    PubMed Central

    Fu, Guifang; Wan, Nicholas J. A.; Baker, Joseph M.; Montgomery, James W.; Evans, Julia L.; Gillam, Ronald B.

    2016-01-01

    Functional near infrared spectroscopy (fNIRS) is a neuroimaging technology that enables investigators to indirectly monitor brain activity in vivo through relative changes in the concentration of oxygenated and deoxygenated hemoglobin. One of the key features of fNIRS is its superior temporal resolution, with dense measurements over very short periods of time (100 ms increments). Unfortunately, most statistical analysis approaches in the existing literature have not fully utilized the high temporal resolution of fNIRS. For example, many analysis procedures are based on linearity assumptions that only extract partial information, thereby neglecting the overall dynamic trends in fNIRS trajectories. The main goal of this article is to assess the ability of a functional data analysis (FDA) approach for detecting significant differences in hemodynamic responses recorded by fNIRS. Children with and without SLI wore two, 3 × 5 fNIRS caps situated over the bilateral parasylvian areas as they completed a language comprehension task. FDA was used to decompose the high dimensional hemodynamic curves into the mean function and a few eigenfunctions to represent the overall trend and variation structures over time. Compared to the most popular GLM, we did not assume any parametric structure and let the data speak for itself. This analysis identified significant differences between the case and control groups in the oxygenated hemodynamic mean trends in the bilateral inferior frontal and left inferior posterior parietal brain regions. We also detected significant group differences in the deoxygenated hemodynamic mean trends in the right inferior posterior parietal cortex and left temporal parietal junction. These findings, using dramatically different approaches, experimental designs, data sets, and foci, were consistent with several other reports, confirming group differences in the importance of these two areas for syntax comprehension. The proposed FDA was consistent with the

  5. Control analysis of an underactuated spacecraft under disturbance

    NASA Astrophysics Data System (ADS)

    Wang, Dongxia; Jia, Yinghong; Jin, Lei; Xu, Shijie

    2013-02-01

    Based on the nonlinear controllability theory, this paper analyzes the attitude controllability for an underactuated spacecraft using two or one thrusters in sequence. In order to provide a preconditional guide on designing the control law for the underactuated attitude control system in the actual case, the underactuated spacecraft with respect to the orbit frame is investigated in the presence of periodical oscillation disturbance. First, attitude dynamic model was established for an underactuated spacecraft actuated by three thrusters, one or two of which has failed separately, and the special orthogonal group (SO(3)) is deployed to describe the attitude motions. Second, Liouville theorem and Poincaré's recurrence theorem were used to confirm that the drift field is Weakly Positively Poisson Stable (WPPS). Furthermore, the sufficient and necessary condition of controllability was obtained on the basis of Lie Algebra Rank Condition (LARC). Finally, according to the case of two available thrusters, angular velocity stabilization and three-axis attitude stabilization control laws are designed, and proved by Lyapunov stability theory and LaSalle invariant theorem. The analysis and simulation results illustrate the feasibility of the proposed control law.

  6. Assessment of quality control approaches for metagenomic data analysis

    PubMed Central

    Zhou, Qian; Ning, Kang

    2014-01-01

    Currently there is an explosive increase of the next-generation sequencing (NGS) projects and related datasets, which have to be processed by Quality Control (QC) procedures before they could be utilized for omics analysis. QC procedure usually includes identification and filtration of sequencing artifacts such as low-quality reads and contaminating reads, which would significantly affect and sometimes mislead downstream analysis. Quality control of NGS data for microbial communities is especially challenging. In this work, we have evaluated and compared the performance and effects of various QC pipelines on different types of metagenomic NGS data and from different angles, based on which general principles of using QC pipelines were proposed. Results based on both simulated and real metagenomic datasets have shown that: firstly, QC-Chain is superior in its ability for contamination identification for metagenomic NGS datasets with different complexities with high sensitivity and specificity. Secondly, the high performance computing engine enabled QC-Chain to achieve a significant reduction in processing time compared to other pipelines based on serial computing. Thirdly, QC-Chain could outperform other tools in benefiting downstream metagenomic data analysis. PMID:25376098

  7. Assessment of quality control approaches for metagenomic data analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Qian; Su, Xiaoquan; Ning, Kang

    2014-11-01

    Currently there is an explosive increase of the next-generation sequencing (NGS) projects and related datasets, which have to be processed by Quality Control (QC) procedures before they could be utilized for omics analysis. QC procedure usually includes identification and filtration of sequencing artifacts such as low-quality reads and contaminating reads, which would significantly affect and sometimes mislead downstream analysis. Quality control of NGS data for microbial communities is especially challenging. In this work, we have evaluated and compared the performance and effects of various QC pipelines on different types of metagenomic NGS data and from different angles, based on which general principles of using QC pipelines were proposed. Results based on both simulated and real metagenomic datasets have shown that: firstly, QC-Chain is superior in its ability for contamination identification for metagenomic NGS datasets with different complexities with high sensitivity and specificity. Secondly, the high performance computing engine enabled QC-Chain to achieve a significant reduction in processing time compared to other pipelines based on serial computing. Thirdly, QC-Chain could outperform other tools in benefiting downstream metagenomic data analysis.

  8. Simulation of Greenhouse Climate Monitoring and Control with Wireless Sensor Network and Event-Based Control

    PubMed Central

    Pawlowski, Andrzej; Guzman, Jose Luis; Rodríguez, Francisco; Berenguel, Manuel; Sánchez, José; Dormido, Sebastián

    2009-01-01

    Monitoring and control of the greenhouse environment play a decisive role in greenhouse production processes. Assurance of optimal climate conditions has a direct influence on crop growth performance, but it usually increases the required equipment cost. Traditionally, greenhouse installations have required a great effort to connect and distribute all the sensors and data acquisition systems. These installations need many data and power wires to be distributed along the greenhouses, making the system complex and expensive. For this reason, and others such as unavailability of distributed actuators, only individual sensors are usually located in a fixed point that is selected as representative of the overall greenhouse dynamics. On the other hand, the actuation system in greenhouses is usually composed by mechanical devices controlled by relays, being desirable to reduce the number of commutations of the control signals from security and economical point of views. Therefore, and in order to face these drawbacks, this paper describes how the greenhouse climate control can be represented as an event-based system in combination with wireless sensor networks, where low-frequency dynamics variables have to be controlled and control actions are mainly calculated against events produced by external disturbances. The proposed control system allows saving costs related with wear minimization and prolonging the actuator life, but keeping promising performance results. Analysis and conclusions are given by means of simulation results. PMID:22389597

  9. Model based controls and the AGS booster controls system architecture

    SciTech Connect

    Casella, R.A.

    1987-08-18

    The Heavy Ion Transfer Line used to inject heavy ions created at the Tandem Van de Graaff into the Alternating Gradient Synchrotron (AGS) is briefly discussed, particularly as regards its control system. (LEW)

  10. Economic analysis of HPAI control in the Netherlands II: comparison of control strategies.

    PubMed

    Longworth, N; Mourits, M C M; Saatkamp, H W

    2014-06-01

    A combined epidemiological-economic modelling approach was used to analyse strategies for highly pathogenic avian influenza (HPAI) control for the Netherlands. The modelling framework used was InterSpread Plus (ISP), a spatially based, stochastic and dynamic simulation model. A total of eight control strategies were analysed, including pre-emptive depopulation and vaccination strategies. The analysis was carried out for three different regions in the Netherlands: high-, medium- and low-density areas (HDA, MDA and LDA, respectively). The analysis included the veterinary impact (e.g. number of infected premises and duration), but was particularly focused on the impact on direct costs (DC) and direct consequential costs. The efficient set of control strategies for HDA and MDA included strategies based on either pre-emptive depopulation only or combined vaccination and pre-emptive depopulation: D2 (pre-emptive depopulation within a radius of 2 km), RV3 + D1 (ring vaccination within a radius of 3 km and additional pre-emptive depopulation within a radius of 1 km) and PV + D1 (preventive vaccination in non-affected HDAs and pre-emptive depopulation within a radius of 1 km in the affected HDA). Although control solely based on depopulation in most cases showed to be effective for LDA, pre-emptive depopulation showed to have an additional advantage in these areas, that is, prevention of 'virus jumps' to other areas. The pros and cons of the efficient control strategies were discussed, for example, public perception and risk of export restrictions. It was concluded that for the Netherlands control of HPAI preferably should be carried out using strategies including pre-emptive depopulation with or without vaccination. Particularly, the short- and long-term implications on export, that is, indirect consequential costs (ICC) and aftermath costs of these strategies, should be analysed further. PMID:23206287

  11. Analysis of Controller Communication in En Route Air Traffic Control.

    ERIC Educational Resources Information Center

    Seamster, Thomas L.; And Others

    To contribute to an understanding of the elements of good air traffic controller communication with the objective of providing recommendations to improve controller communication training, two studies analyzed team communication, ground-air communication, and ground-line communication. The simulated and live traffic analyses examined established…

  12. Controlling biofilm with evidence-based dentifrices.

    PubMed

    Ciancio, Sebastian G

    2011-01-01

    This review summarizes research that has assessed the effectiveness of various antimicrobial-containing dentifrices in preventing and/or reducing a number of oral health problems facing our patients today. The results of these studies indicate that, when compared with a conventional fluoride dentifrice, the triclosan/copolymer/fluoride dentifrice is the one with the most evidence to support its ability to deliver significant oral health benefits with no adverse effects. The benefits maybe summarized as follows: improved levels ofsupragingival plaque control; improved gingival health; reducedlikelihood of gingivitis progressing to periodontitis; arrest progression of periodontitis; prevention of supragingival calculus; and reduction in oral malodor. With increased interest in the association of oral health with systemic health, this dentifrice is well-positioned to help reduce the likelihood of gingivitis establishing itself and possibly developing into periodontitis (Figure 1). It also has the potential to have beneficial effects on general health because of its anti-inflammatory properties. Based on the results presented in this article, it is clear that the general population can derive significant clinical benefits from the daily use of a triclosan/copolymer/fluoride dentifrice. The dental profession should feel confident to recommend its use to patients to improve oral health and maintain or promote overall health. PMID:21462625

  13. Water-based interventions for schistosomiasis control

    PubMed Central

    Evan Secor, William

    2014-01-01

    Mass drug administration with praziquantel is the mainstay of programs for the control of schistosomiasis morbidity. However, there is a growing recognition that treatment alone will not be sufficient for eventually effecting elimination and that additional measures will be required to interrupt transmission. In the absence of a safe and an effective vaccine for human schistosomiasis, the strategies to reduce infection levels will necessarily involve some interventions that affect the water-related stages of the schistosome life cycle: by reducing exposure to infectious water, by moderating availability of the intermediate snail host, or by decreasing contamination of water with egg-containing excreta. While much research on the importance of water on schistosomiasis has been performed, advances in these areas have perhaps languished with the ready availability of a cost-effective treatment. As some endemic areas near a shift to an elimination goal, a better understanding of water-based interventions that can be used alone or in concert with treatment will be needed. Reinvigoration of laboratory, field, and human behavioral aspects of this research now will ensure that the appropriate strategies are available by the time their implementation becomes necessary. PMID:25175875

  14. DC-based magnetic field controller

    DOEpatents

    Kotter, D.K.; Rankin, R.A.; Morgan, J.P.

    1994-05-31

    A magnetic field controller is described for laboratory devices and in particular to dc operated magnetic field controllers for mass spectrometers, comprising a dc power supply in combination with improvements to a Hall probe subsystem, display subsystem, preamplifier, field control subsystem, and an output stage. 1 fig.

  15. DC-based magnetic field controller

    DOEpatents

    Kotter, Dale K.; Rankin, Richard A.; Morgan, John P,.

    1994-01-01

    A magnetic field controller for laboratory devices and in particular to dc operated magnetic field controllers for mass spectrometers, comprising a dc power supply in combination with improvements to a hall probe subsystem, display subsystem, preamplifier, field control subsystem, and an output stage.

  16. Smart Engines Via Advanced Model Based Controls

    SciTech Connect

    Allain, Marc

    2000-08-20

    A ''new'' process for developing control systems - Less engine testing - More robust control system - Shorter development cycle time - ''Smarter'' approach to engine control - On-board models describe engine behavior - Shorter, systematic calibration process - Customer and legislative requirements designed-in.

  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 concept for aiding air traffic controllers in efficiently spacing traffic and meeting scheduled arrival times at a metering fix was developed and tested in a real time simulation. The automation aid, referred to as the ground based 4-D descent advisor (DA), is based on accurate models of aircraft performance and weather conditions. The DA generates suggested clearances, including both top-of-descent-point and speed-profile data, for one or more aircraft in order to achieve specific time or distance separation objectives. The DA algorithm is used by the air traffic controller to resolve conflicts and issue advisories to arrival aircraft. A joint simulation was conducted using a piloted simulator and an advanced concept air traffic control simulation to study the acceptability and accuracy of the DA automation aid from both the pilot's and the air traffic controller's perspectives. The results of the piloted simulation are examined. 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 + or - 20 sec at the metering fix. An analysis of errors generated in turns resulted in further enhancements of the algorithm to improve the predictive accuracy. Evaluations by pilots indicate general support for the concept and provide specific recommendations for improvement.

  18. Robustness analysis applied to substructure controller synthesis

    NASA Technical Reports Server (NTRS)

    Gonzalez-Oberdoerffer, Marcelo F.; Craig, Roy R., Jr.

    1993-01-01

    The stability and robustness of the controlled system obtained via the substructure control synthesis (SCS) method of Su et al. (1990) were examined using a six-bay truss model, and employing an LQG control design method to obtain controllers for two separate structures. It is found that the assembled controller provides a stability in this instance. A qualitative assessment of the stability robustness of the system with controller designed with the SCS method is provided by obtaining a controller using the complete truss model and comparing the robustness of the corresponding closed-loop systems.

  19. Adaptive control of a Stewart platform-based manipulator

    NASA Technical Reports Server (NTRS)

    Nguyen, Charles C.; Antrazi, Sami S.; Zhou, Zhen-Lei; Campbell, Charles E., Jr.

    1993-01-01

    A joint-space adaptive control scheme for controlling noncompliant motion of a Stewart platform-based manipulator (SPBM) was implemented in the Hardware Real-Time Emulator at Goddard Space Flight Center. The six-degrees of freedom SPBM uses two platforms and six linear actuators driven by dc motors. The adaptive control scheme is based on proportional-derivative controllers whose gains are adjusted by an adaptation law based on model reference adaptive control and Liapunov direct method. It is concluded that the adaptive control scheme provides superior tracking capability as compared to fixed-gain controllers.

  20. PROBABILITY BASED CORROSION CONTROL FOR WASTE TANKS - PART II

    SciTech Connect

    Hoffman, E.; Edwards, T.

    2010-12-09

    As part of an ongoing study to evaluate the discontinuity in the corrosion controls at the SRS tank farm, a study was conducted this year to assess the minimum concentrations below 1 molar nitrate, see Figure 1. Current controls on the tank farm solution chemistry are in place to prevent the initiation and propagation of pitting and stress corrosion cracking in the primary steel waste tanks. The controls are based upon a series of experiments performed with simulated solutions on materials used for construction of the tanks, namely ASTM A537 carbon steel (A537). During FY09, an experimental program was undertaken to investigate the risk associated with reducing the minimum molar nitrite concentration required to confidently inhibit pitting in dilute solutions (i.e., less than 1 molar nitrate). The experimental results and conclusions herein provide a statistical basis to quantify the probability of pitting for the tank wall exposed to various solutions with dilute concentrations of nitrate and nitrite. Understanding the probability for pitting will allow the facility to make tank-specific risk-based decisions for chemistry control. Based on previous electrochemical testing, a statistical test matrix was developed to refine and solidify the application of the statistical mixture/amount model to corrosion of A537 steel. A mixture/amount model was identified based on statistical analysis of recent and historically collected electrochemical data. This model provides a more complex relationship between the nitrate and nitrite concentrations and the probability of pitting than is represented by the model underlying the current chemistry control program, and its use may provide a technical basis for the utilization of less nitrite to inhibit pitting at concentrations below 1 molar nitrate. FY09 results fit within the mixture/amount model, and further refine the nitrate regime in which the model is applicable. The combination of visual observations and cyclic

  1. Investigating the capability of a control chart based on functional data for daily PM10 monitoring

    NASA Astrophysics Data System (ADS)

    Shaadan, Norshahida; Jemain, Abdul Aziz; Deni, Sayang Mohd

    2015-02-01

    A control chart based on functional data (FD) has been proposed to be used as a tool for detecting anomalies and for assessing the trend of daily PM10. In this study, the capability of the FD control chart is investigated. The performance of the FD control chart is compared to the control charts based on the average (AV) and multivariate (MV) data. Daily PM10 indices for AV control chart are the average values while the indices for the MV and FD control charts are computed based on the Principal Component Analysis (PCA) model. The experimentation is conducted using real PM10 data from the Shah Alam air quality monitoring station located at the west of Peninsular Malaysia to investigate the performance of the control charts. The results of the first stage analysis have shown that the FD control chart outperforms the AV and MV control charts in detecting PM10 anomalies of extreme levels. Using a similar number of principal components, it is also found that the PCA model based on FD is able to capture more information compared to the PCA model based on MV. By means of the operating characteristics (OC) curve, the results from the subsequent analysis also reveal that the FD control chart is more sensitive to the changes in the control limits. Overall, the study results have indicated that the FD control chart is worth pursuing.

  2. Single-agent bortezomib or bortezomib-based regimens as consolidation therapy after autologous hematopoietic stem cell transplantation in multiple myeloma: a meta-analysis of randomized controlled trials

    PubMed Central

    Gao, Minjie; Yang, Guang; Han, Ying; Kong, Yuanyuan; Wu, Huiqun; Tao, Yi; Zhan, Fenghuang; Shi, Jumei; Wu, Xiaosong

    2015-01-01

    The efficacy and safety of single-agent bortezomib or bortezomib-based regimens as consolidation therapy after autologous hematopoietic stem cell transplantation (ASCT) in patients with multiple myeloma (MM) has been in question. To address the issue, we conducted a meta-analysis of two randomized double-blind placebo-controlled studies involving a total of 691 patients. The primary outcomes of interest were progression-free survival (PFS) and response rate. Secondary outcomes included overall survival (OS) and adverse events. There was a marked benefit in 3-year PFS with bortezomib (Odds Ratio [OR] = 1.52, 95% confidence interval [CI] = 1.11 to 2.08), whereas there was no difference in 3-year overall survival (OS; OR = 0.91, 95% CI = 0.60 to 1.37). More bortezomib-treated paitents achieved at least a very good partial response (≥ VGPR) (OR = 1.73, 95% CI = 1.19 to 2.51). The rate of complete response or near-complete response (CR/nCR) was significantly higher with bortezomib consolidation therapy (OR = 1.62, 95% CI = 1.18 to 2.22). For adverse events, more patients in the bortezomib consolidation therapy arm experienced peripheral neuropathy (OR = 4.03, 95% CI = 2.72 to 5.96). Significant differences were also seen with those experiencing peripheral neuropathy greater than grade 2 (OR = 4.26, 95% CI = 1.06 to 17.11). Based on these results, we conclude that single-agent bortezomib or bortezomib-based regimens as consolidation therapy after ASCT in patients with MM was effective in the improvement of PFS and response rate. However, peripheral neuropathy must be closely monitored. PMID:26550130

  3. Adaptive muffler based on controlled flow valves.

    PubMed

    Šteblaj, Peter; Čudina, Mirko; Lipar, Primož; Prezelj, Jurij

    2015-06-01

    An adaptive muffler with a flexible internal structure is considered. Flexibility is achieved using controlled flow valves. The proposed adaptive muffler is able to adapt to changes in engine operating conditions. It consists of a Helmholtz resonator, expansion chamber, and quarter wavelength resonator. Different combinations of the control valves' states at different operating conditions define the main working principle. To control the valve's position, an active noise control approach was used. With the proposed muffler, the transmission loss can be increased by more than 10 dB in the selected frequency range. PMID:26093462

  4. Design and Performance Analysis of Incremental Networked Predictive Control Systems.

    PubMed

    Pang, Zhong-Hua; Liu, Guo-Ping; Zhou, Donghua

    2016-06-01

    This paper is concerned with the design and performance analysis of networked control systems with network-induced delay, packet disorder, and packet dropout. Based on the incremental form of the plant input-output model and an incremental error feedback control strategy, an incremental networked predictive control (INPC) scheme is proposed to actively compensate for the round-trip time delay resulting from the above communication constraints. The output tracking performance and closed-loop stability of the resulting INPC system are considered for two cases: 1) plant-model match case and 2) plant-model mismatch case. For the former case, the INPC system can achieve the same output tracking performance and closed-loop stability as those of the corresponding local control system. For the latter case, a sufficient condition for the stability of the closed-loop INPC system is derived using the switched system theory. Furthermore, for both cases, the INPC system can achieve a zero steady-state output tracking error for step commands. Finally, both numerical simulations and practical experiments on an Internet-based servo motor system illustrate the effectiveness of the proposed method. PMID:26186798

  5. Algorithm for calculating torque base in vehicle traction control system

    NASA Astrophysics Data System (ADS)

    Li, Hongzhi; Li, Liang; Song, Jian; Wu, Kaihui; Qiao, Yanjuan; Liu, Xingchun; Xia, Yongguang

    2012-11-01

    Existing research on the traction control system(TCS) mainly focuses on control methods, such as the PID control, fuzzy logic control, etc, aiming at achieving an ideal slip rate of the drive wheel over long control periods. The initial output of the TCS (referred to as the torque base in this paper), which has a great impact on the driving performance of the vehicle in early cycles, remains to be investigated. In order to improve the control performance of the TCS in the first several cycles, an algorithm is proposed to determine the torque base. First, torque bases are calculated by two different methods, one based on states judgment and the other based on the vehicle dynamics. The confidence level of the torque base calculated based on the vehicle dynamics is also obtained. The final torque base is then determined based on the two torque bases and the confidence level. Hardware-in-the-loop(HIL) simulation and vehicle tests emulating sudden start on low friction roads have been conducted to verify the proposed algorithm. The control performance of a PID-controlled TCS with and without the proposed torque base algorithm is compared, showing that the proposed algorithm improves the performance of the TCS over the first several cycles and enhances about 5% vehicle speed by contrast. The proposed research provides a more proper initial value for TCS control, and improves the performance of the first several control cycles of the TCS.

  6. Thermal modeling, analysis and control of a space suit

    NASA Astrophysics Data System (ADS)

    Campbell, Anthony Bruce

    The thermal dynamics of two space suits, the Space Shuttle EMU and the MPLSS Advanced Space Suit, are considered as they relate to astronaut thermal comfort control. The activities documented in this dissertation cover three related areas, modeling, analysis, and control. A detailed dynamic lumped capacitance thermal model of the operational Space Shuttle EMU is used to analyze the thermal dynamics of the system with observations verified using experimental and flight data. Prior to using the model to define performance characteristics and limitations for the space suit, the model is first evaluated and improved. This evaluation includes determining the effect of various model parameters on model performance and quantifying various temperature prediction errors in terms of heat transfer and heat storage. The thermal dynamics and design of an Advanced Space Suit are next considered. A transient model of the MPLSS Advanced Space Suit design is developed and implemented using MATLAB/Simulink, to help with sizing, with design evaluation, and with the development of an automatic thermal comfort control strategy. The model is described and the thermal characteristics of the Advanced Space Suit are investigated including various parametric design studies. The steady state performance envelope for the Advanced Space Suit is defined in terms of the thermal environment and human metabolic rate and the transient response of the human-suit-MPLSS system is analyzed. The observations and insights about the thermal dynamics of a space suit are then applied to the automatic thermal comfort control of the MPLSS Advanced Space Suit. Automatic thermal comfort control for the Advanced Space Suit is investigated using three proposed strategies. These strategies use a transient thermal comfort definition based on body heat storage. The first strategy is measurement based using a proposed body heat storage estimation method to determine the astronaut's thermal state. The second strategy

  7. Model analysis and nonlinear control of air compressors

    NASA Astrophysics Data System (ADS)

    Sari, Gholam-Reza

    For decades, gas turbines have been important, widespread, and reliable devices in the field of power generation, petrochemical industry, and aeronautics. They employ centrifugal and axial compressors which suffer from aerodynamic instabilities, namely, surge and rotating stall. These performance limiting instabilities can cause component stress, lifespan reduction, noise, and vibration. Furthermore, in variable speed axial compressors (VSACs), speed variations affect the system stability and can lead to surge and rotating stall. This limits the rate of speed variations and results in important performance penalties. The present work firstly addresses the bifurcation analysis of VSACs' model to investigate the impact of speed dynamics on the stability of efficient operating points. Here, the rate of speed variations (acceleration rate) is defined as a new parameter of the model and a detailed numerical bifurcation analysis is provided. The results of time-domain simulations not only validate the results of bifurcation analysis, but also broaden our knowledge about the transient response of the model, which is a matter of importance as well. The analysis reveals that speed variations can lead to a fully developed rotating stall as well as the previously reported temporary stall developments. The results show that the developed instabilities depend to a great extent on the acceleration rate. The impact of other key issues such as throttle gain, viscosity factor, initial speed, final speed, and the contribution of stall modes are also explored. From the control point of view, despite reported achievements, robust control design for compression systems remains a challenging problem. In this work, at first, two nonlinear approaches are proposed to tackle the stability problem of constant-speed axial compressors (CSACs). The first approach is a robust passivity-based control and the second one is a second order sliding mode control. The approaches tackle the challenging

  8. Model-Based, Multiscale Self-Tuning Controller Developed for Active Combustion Control

    NASA Technical Reports Server (NTRS)

    Le, Dzu K.

    2005-01-01

    New challenges concerning system health-monitoring and life-extending robust controls for the Ultra-Efficient Engine Technology Project, as well as other advanced engine and power system concepts at NASA and elsewhere, have renewed the control community s interest in smart, model-based methods. In particular, these challenges have further motivated efforts at the NASA Glenn Research Center to exploit the versatility and superiority of the dynamic features extraction of multiscale analysis for controls--such as with "wavelets" and "wavelet filter-banks.' The accomplishments reported herein pertain to the active suppression of combustion instabilities in liquid-fuel combustors via fuel modulation. The fundamentals and initial success of this innovation were reported for a unique demonstration of active combustion control (a research collaboration of NASA Glenn with Pratt & Whitney and the United Technologies Research Center, UTRC). This demonstration, conducted in 2002 at UTRC on the NASA single nozzle rig (SNR) combustor, was the first known suppression of high-frequency instability with a liquid-fueled combustor. The SNR is based on a high-powered military engine combustor that exhibited well-known instabilities.

  9. Analysis of virtual passive controllers for flexible space structures

    NASA Technical Reports Server (NTRS)

    Williams, Trevor W.

    1992-01-01

    The dynamics of flexible spacecraft are not usually well known before launch. This makes it important to develop controllers for such systems that can never be destabilized by perturbations in the structural model. Virtual passive controllers, or active vibration absorbers, possess this guaranteed stability property; they mimic a fictitious flexible structure attached to the true physical one. This report analyzes the properties of such controllers, and shows that disturbance absorption behavior can be naturally described in terms of a set of virtual zeros that they introduce into the closed-loop dynamics of the system. Based on this analysis, techniques are then derived for selecting the active vibration absorber internal parameters, i.e., the gain matrices of such controllers, so as to achieve specified control objectives. Finally, the effects on closed-loop stability of small delays in the feedback loop are investigated. Such delays would typically be introduced by a digital implementation of an active vibration absorber. It is shown that these delays only affect the real parts of the eigenvalues of a lightly-damped structure. Furthermore, it is only the high-frequency modes that are destabilized by delays; low-frequency modes are actually made more heavily damped. Eigenvalue perturbation methods are used to obtain accurate predictions of the critical delay at which a given system will become unstable; these methods also determine which mode is critical.

  10. Analysis of design control values for TEP

    SciTech Connect

    Carlson, Bryan J

    2008-01-01

    The Tokamak Exhaust Processing (TEP) Performance Requirements Report (USITER-13201-TD0005-R00), date May 29, 2007 defined feed sources for TEP quantities and approximate flow rate of gases from these individual sources. In addition, the report identified the approximate periods of time (during Burn and Dwell, 'Silent Shift', etc.) that these gases would be transferred to TEP. This report did not take into account the detailed, time dependent, sequencing options for receiving gases from these feed sources. Sequencing is critical in defining the actual design basis values (flow rates, etc.) for TEP. This report analyzes the time dependent sequencing of feed flows to TEP and defines the ,design basis values. This analysis is based on the values presented in the TEP Performance Requirements Report (TEP PRR), and indicates that the ITER Burn and Dwell, Silent Shift Following 16 hours of Burn and Dwell, Glow Discharge Cleaning (GDC), and Silent Shift following 100 hours of GDC scenarios are the limiting scenarios from which the design basis values will be defined.

  11. Supercritical carbon dioxide cycle control analysis.

    SciTech Connect

    Moisseytsev, A.; Sienicki, J. J.

    2011-04-11

    This report documents work carried out during FY 2008 on further investigation of control strategies for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converters. The main focus of the present work has been on investigation of the S-CO{sub 2} cycle control and behavior under conditions not covered by previous work. An important scenario which has not been previously calculated involves cycle operation for a Sodium-Cooled Fast Reactor (SFR) following a reactor scram event and the transition to the primary coolant natural circulation and decay heat removal. The Argonne National Laboratory (ANL) Plant Dynamics Code has been applied to investigate the dynamic behavior of the 96 MWe (250 MWt) Advanced Burner Test Reactor (ABTR) S-CO{sub 2} Brayton cycle following scram. The timescale for the primary sodium flowrate to coast down and the transition to natural circulation to occur was calculated with the SAS4A/SASSYS-1 computer code and found to be about 400 seconds. It is assumed that after this time, decay heat is removed by the normal ABTR shutdown heat removal system incorporating a dedicated shutdown heat removal S-CO{sub 2} pump and cooler. The ANL Plant Dynamics Code configured for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) was utilized to model the S-CO{sub 2} Brayton cycle with a decaying liquid metal coolant flow to the Pb-to-CO{sub 2} heat exchangers and temperatures reflecting the decaying core power and heat removal by the cycle. The results obtained in this manner are approximate but indicative of the cycle transient performance. The ANL Plant Dynamics Code calculations show that the S-CO{sub 2} cycle can operate for about 400 seconds following the reactor scram driven by the thermal energy stored in the reactor structures and coolant such that heat removal from the reactor exceeds the decay heat generation. Based on the results, requirements for the shutdown heat removal system may be defined

  12. Using Conceptual Analysis To Build Knowledge Bases.

    ERIC Educational Resources Information Center

    Shinghal, Rajjan; Le Xuan, Albert

    This paper describes the methods and techniques called Conceptual Analysis (CA), a rigorous procedure to generate (without involuntary omissions and repetitions) knowledge bases for the development of knowledge-based systems. An introduction is given of CA and how it can be used to produce knowledge bases. A discussion is presented on what is…

  13. Sensory-based expert monitoring and control

    NASA Astrophysics Data System (ADS)

    Yen, Gary G.

    1999-03-01

    Field operators use their eyes, ears, and nose to detect process behavior and to trigger corrective control actions. For instance: in daily practice, the experienced operator in sulfuric acid treatment of phosphate rock may observe froth color or bubble character to control process material in-flow. Or, similarly, (s)he may use acoustic sound of cavitation or boiling/flashing to increase or decrease material flow rates in tank levels. By contrast, process control computers continue to be limited to taking action on P, T, F, and A signals. Yet, there is sufficient evidence from the fields that visual and acoustic information can be used for control and identification. Smart in-situ sensors have facilitated potential mechanism for factory automation with promising industry applicability. In respond to these critical needs, a generic, structured health monitoring approach is proposed. The system assumes a given sensor suite will act as an on-line health usage monitor and at best provide the real-time control autonomy. The sensor suite can incorporate various types of sensory devices, from vibration accelerometers, directional microphones, machine vision CCDs, pressure gauges to temperature indicators. The decision can be shown in a visual on-board display or fed to the control block to invoke controller reconfigurration.

  14. Composition and analysis of a model waste for a CELSS (Controlled Ecological Life Support System)

    NASA Technical Reports Server (NTRS)

    Wydeven, T. J.

    1983-01-01

    A model waste based on a modest vegetarian diet is given, including composition and elemental analysis. Its use is recommended for evaluation of candidate waste treatment processes for a Controlled Ecological Life Support System (CELSS).

  15. New Applications of Variational Analysis to Optimization and Control

    NASA Astrophysics Data System (ADS)

    Mordukhovich, Boris S.

    We discuss new applications of advanced tools of variational analysis and generalized differentiation to a number of important problems in optimization theory, equilibria, optimal control, and feedback control design. The presented results are largely based on the recent work by the author and his collaborators. Among the main topics considered and briefly surveyed in this paper are new calculus rules for generalized differentiation of nonsmooth and set-valued mappings; necessary and sufficient conditions for new notions of linear subextremality and suboptimality in constrained problems; optimality conditions for mathematical problems with equilibrium constraints; necessary optimality conditions for optimistic bilevel programming with smooth and nonsmooth data; existence theorems and optimality conditions for various notions of Pareto-type optimality in problems of multiobjective optimization with vector-valued and set-valued cost mappings; Lipschitzian stability and metric regularity aspects for constrained and variational systems.

  16. Systems Analysis for Material Control and Accountancy Technology (SAMCAT)

    SciTech Connect

    Persiani, P.J., Bucher, R.G.; Rothman, A.B.; Cha, B.K.

    1990-01-01

    The Systems Analysis for Material Control and Accountancy Technology (SAMCAT) is an interactive computer-based management system developed for the Department of Energy Office of Safeguards and Security, to assist in defining and prioritizing measurement upgrades programs for Material Control and Accountancy (MC A). The accountancy upgrades options evaluated by SAMCAT in this study are: (1) improvement of the uncertainties in the SNM measurement methods, (2) reduction of throughputs and/or inventories of SNM, and (3) reduction of the material balance accounting period. The goals of the MC A upgrades program are reduced inventory differences and associated uncertainties, improved detection probabilities for theft/diversion, decreased operating costs, and enhanced material traceability. 6 refs., 3 figs., 2 tabs.

  17. Bounded Linear Stability Margin Analysis of Nonlinear Hybrid Adaptive Control

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.; Boskovic, Jovan D.

    2008-01-01

    This paper presents a bounded linear stability analysis for a hybrid adaptive control that blends both direct and indirect adaptive control. Stability and convergence of nonlinear adaptive control are analyzed using an approximate linear equivalent system. A stability margin analysis shows that a large adaptive gain can lead to a reduced phase margin. This method can enable metrics-driven adaptive control whereby the adaptive gain is adjusted to meet stability margin requirements.

  18. Spectral radiative property control method based on filling solution

    NASA Astrophysics Data System (ADS)

    Jiao, Y.; Liu, L. H.; Hsu, P.-f.

    2014-01-01

    Controlling thermal radiation by tailoring spectral properties of microstructure is a promising method, can be applied in many industrial systems and have been widely researched recently. Among various property tailoring schemes, geometry design of microstructures is a commonly used method. However, the existing radiation property tailoring is limited by adjustability of processed microstructures. In other words, the spectral radiative properties of microscale structures are not possible to change after the gratings are fabricated. In this paper, we propose a method that adjusts the grating spectral properties by means of injecting filling solution, which could modify the thermal radiation in a fabricated microstructure. Therefore, this method overcomes the limitation mentioned above. Both mercury and water are adopted as the filling solution in this study. Aluminum and silver are selected as the grating materials to investigate the generality and limitation of this control method. The rigorous coupled-wave analysis is used to investigate the spectral radiative properties of these filling solution grating structures. A magnetic polaritons mechanism identification method is proposed based on LC circuit model principle. It is found that this control method could be used by different grating materials. Different filling solutions would enable the high absorption peak to move to longer or shorter wavelength band. The results show that the filling solution grating structures are promising for active control of spectral radiative properties.

  19. Microturbine control based on fuzzy neural network

    NASA Astrophysics Data System (ADS)

    Yan, Shijie; Bian, Chunyuan; Wang, Zhiqiang

    2006-11-01

    As microturbine generator (MTG) is a clean, efficient, low cost and reliable energy supply system. From outside characteristics of MTG, it is multi-variable, time-varying and coupling system, so it is difficult to be identified on-line and conventional control law adopted before cannot achieve desirable result. A novel fuzzy-neural networks (FNN) control algorithm was proposed in combining with the conventional PID control. In the paper, IF-THEN rules for tuning were applied by a first-order Sugeno fuzzy model with seven fuzzy rules and the membership function was given as the continuous GAUSSIAN function. Some sample data were utilized to train FNN. Through adjusting shape of membership function and weight continually, objective of auto-tuning fuzzy-rules can be achieved. The FNN algorithm had been applied to "100kW Microturbine control and power converter system". The results of simulation and experiment are shown that the algorithm can work very well.

  20. Tikhonov regularization-based operational transfer path analysis

    NASA Astrophysics Data System (ADS)

    Cheng, Wei; Lu, Yingying; Zhang, Zhousuo

    2016-06-01

    To overcome ill-posed problems in operational transfer path analysis (OTPA), and improve the stability of solutions, this paper proposes a novel OTPA based on Tikhonov regularization, which considers both fitting degrees and stability of solutions. Firstly, fundamental theory of Tikhonov regularization-based OTPA is presented, and comparative studies are provided to validate the effectiveness on ill-posed problems. Secondly, transfer path analysis and source contribution evaluations for numerical cases studies on spherical radiating acoustical sources are comparatively studied. Finally, transfer path analysis and source contribution evaluations for experimental case studies on a test bed with thin shell structures are provided. This study provides more accurate transfer path analysis for mechanical systems, which can benefit for vibration reduction by structural path optimization. Furthermore, with accurate evaluation of source contributions, vibration monitoring and control by active controlling vibration sources can be effectively carried out.

  1. Performance Analysis: Work Control Events Identified January - August 2010

    SciTech Connect

    De Grange, C E; Freeman, J W; Kerr, C E; Holman, G; Marsh, K; Beach, R

    2011-01-14

    , training of the workforce began and as of the time of this report more than 50% of authorized Integration Work Sheets (IWS) use the activity-based planning process. In 2010, LSO independently reviewed the work planning and control process and confirmed to the Laboratory that the Integrated Safety Management (ISM) System was implemented. LLNL conducted a cross-directorate management self-assessment of work planning and control and is developing actions to respond to the issues identified. Ongoing efforts to strengthen the work planning and control process and to improve the quality of LLNL work packages are in progress: completion of remaining actions in response to the 2009 DOE Office of Health, Safety, and Security (HSS) evaluation of LLNL's ISM System; scheduling more than 14 work planning and control self-assessments in FY11; continuing to align subcontractor work control with the Institutional work planning and control system; and continuing to maintain the electronic IWS application. The 24 events included in this analysis were caused by errors in the first four of the five ISMS functions. The most frequent cause was errors in analyzing the hazards (Function 2). The second most frequent cause was errors occurring when defining the work (Function 1), followed by errors during the performance of work (Function 4). Interestingly, very few errors in developing controls (Function 3) resulted in events. This leads one to conclude that if improvements are made to defining the scope of work and analyzing the potential hazards, LLNL may reduce the frequency or severity of events. Analysis of the 24 events resulted in the identification of ten common causes. Some events had multiple causes, resulting in the mention of 39 causes being identified for the 24 events. The most frequent cause was workers, supervisors, or experts believing they understood the work and the hazards but their understanding was incomplete. The second most frequent cause was unclear, incomplete or

  2. An enhanced 8086-based CAMAC crate controller

    SciTech Connect

    Dawson, J.W.; Bayer, J.B.; Chan, L.; Ciarlette, D.; Haberichter, W.N.; Stanek, R.W.

    1987-02-01

    An enhanced CAMAC crate controller (ECC) has been developed for data handling for Fermilab experiment E-704. The module also is currently used in an experiment to make a precise measurement of the weak vector coupling constant. The ECC incorporates hardware to do block transfers (DMA) of CAMAC modules within the crate at several times effective CAMAC rates, or it may e programmed to do individual CAMAC transfers. If desired, data may be rippled out an ECL port to fast ECL devices, or may be written in RAM for processing within the controller itself. The EEC is implemented with the CAMAC Request/Grant protocol for use with an A-2 crate controller, allowing the ECC to be used either as an auxiliary controller or crate controller. Trigger logic in the controller allows the device to respond to any of three triggers by initiating a DMA, or dedicated crates may be daisy-chained, one crate providing a trigger to the next at the conclusion of each DMA. The device is built as much as possible in High Performance CMOS logic using surface mount techniques, on two 8-layer printed circuit cards.

  3. Manufacturing control: A basis for analysis

    NASA Astrophysics Data System (ADS)

    Bugg, N.

    1989-11-01

    The application of elementary control theory to manufacturing systems demonstrating how the organization of basic shop-floor logistics can be optimized prior to the introduction of computer technology is explored. A control structure is introduced and applied to manufacturing systems, breaking the problem into its constituent parts in such a way that the advantages of improved control technology become more apparent and more readily implementable.

  4. Economic analysis of HPAI control in the Netherlands I: epidemiological modelling to support economic analysis.

    PubMed

    Longworth, N; Mourits, M C M; Saatkamp, H W

    2014-06-01

    Economic analysis of control strategies for contagious diseases is a necessity in the development of contingency plans. Economic impacts arising from epidemics such as highly pathogenic avian influenza (HPAI) consist of direct costs (DC), direct consequential costs (DCC), indirect consequential costs (ICC) and aftermath costs (AC). Epidemiological models to support economic analysis need to provide adequate outputs for these critical economic parameters. Of particular importance for DCC, ICC and AC is the spatial production structure of a region. Spatial simulation models are therefore particularly suited for economic analysis; however, they often require a large number of parameters. The aims of this study are (i) to provide an economic rationale of epidemiological modelling in general, (ii) to provide a transparent description of the parameterization of a spatially based epidemiological model for the analysis of HPAI control in the Netherlands and (iii) to discuss the validity and usefulness of this model for subsequent economic analysis. In the model, HPAI virus transmission occurs via local spread and animal movements. Control mechanisms include surveillance and tracing, movement restrictions and depopulation. Sensitivity analysis of key parameters indicated that the epidemiological outputs with the largest influence on the economic impacts (i.e. epidemic duration and number of farms in the movement restriction zone) were more robust than less influential indicators (i.e. number of infected farms). Economically relevant outputs for strategy comparison were most sensitive to the relative role of the different transmission parameters. The default simulation and results of the sensitivity analysis were consistent with the general outcomes of known HPAI models. Comparison was, however, limited due to the absence of some economically relevant outputs. It was concluded that the model creates economically relevant, adequate and credible output for subsequent use in

  5. Control of a mechanical aeration process via topological sensitivity analysis

    NASA Astrophysics Data System (ADS)

    Abdelwahed, M.; Hassine, M.; Masmoudi, M.

    2009-06-01

    The topological sensitivity analysis method gives the variation of a criterion with respect to the creation of a small hole in the domain. In this paper, we use this method to control the mechanical aeration process in eutrophic lakes. A simplified model based on incompressible Navier-Stokes equations is used, only considering the liquid phase, which is the dominant one. The injected air is taken into account through local boundary conditions for the velocity, on the injector holes. A 3D numerical simulation of the aeration effects is proposed using a mixed finite element method. In order to generate the best motion in the fluid for aeration purposes, the optimization of the injector location is considered. The main idea is to carry out topological sensitivity analysis with respect to the insertion of an injector. Finally, a topological optimization algorithm is proposed and some numerical results, showing the efficiency of our approach, are presented.

  6. Uncertainty Modeling for Structural Control Analysis and Synthesis

    NASA Technical Reports Server (NTRS)

    Campbell, Mark E.; Crawley, Edward F.

    1996-01-01

    The development of an accurate model of uncertainties for the control of structures that undergo a change in operational environment, based solely on modeling and experimentation in the original environment is studied. The application used throughout this work is the development of an on-orbit uncertainty model based on ground modeling and experimentation. A ground based uncertainty model consisting of mean errors and bounds on critical structural parameters is developed. The uncertainty model is created using multiple data sets to observe all relevant uncertainties in the system. The Discrete Extended Kalman Filter is used as an identification/parameter estimation method for each data set, in addition to providing a covariance matrix which aids in the development of the uncertainty model. Once ground based modal uncertainties have been developed, they are localized to specific degrees of freedom in the form of mass and stiffness uncertainties. Two techniques are presented: a matrix method which develops the mass and stiffness uncertainties in a mathematical manner; and a sensitivity method which assumes a form for the mass and stiffness uncertainties in macroelements and scaling factors. This form allows the derivation of mass and stiffness uncertainties in a more physical manner. The mass and stiffness uncertainties of the ground based system are then mapped onto the on-orbit system, and projected to create an analogous on-orbit uncertainty model in the form of mean errors and bounds on critical parameters. The Middeck Active Control Experiment is introduced as experimental verification for the localization and projection methods developed. In addition, closed loop results from on-orbit operations of the experiment verify the use of the uncertainty model for control analysis and synthesis in space.

  7. Route-Based Control of Hybrid Electric Vehicles: Preprint

    SciTech Connect

    Gonder, J. D.

    2008-01-01

    Today's hybrid electric vehicle controls cannot always provide maximum fuel savings over all drive cycles. Route-based controls could improve HEV fuel efficiency by 2%-4% and help save nearly 6.5 million gallons of fuel annually.

  8. Stability analysis and controller synthesis for hybrid dynamical systems.

    PubMed

    Heemels, W P M H; De Schutter, B; Lunze, J; Lazar, M

    2010-11-13

    Wherever continuous and discrete dynamics interact, hybrid systems arise. This is especially the case in many technological systems in which logic decision-making and embedded control actions are combined with continuous physical processes. Also for many mechanical, biological, electrical and economical systems the use of hybrid models is essential to adequately describe their behaviour. To capture the evolution of these systems, mathematical models are needed that combine in one way or another the dynamics of the continuous parts of the system with the dynamics of the logic and discrete parts. These mathematical models come in all kinds of variations, but basically consist of some form of differential or difference equations on the one hand and automata or other discrete-event models on the other hand. The collection of analysis and synthesis techniques based on these models forms the research area of hybrid systems theory, which plays an important role in the multi-disciplinary design of many technological systems that surround us. This paper presents an overview from the perspective of the control community on modelling, analysis and control design for hybrid dynamical systems and surveys the major research lines in this appealing and lively research area. PMID:20921005

  9. UHB demonstrator interior noise control flight tests and analysis

    NASA Technical Reports Server (NTRS)

    Simpson, M. A.; Druez, P. M.; Kimbrough, A. J.; Brock, M. P.; Burge, P. L.; Mathur, G. P.; Cannon, M. R.; Tran, B. N.

    1989-01-01

    The measurement and analysis of MD-UHB (McDonnell Douglas Ultra High Bypass) Demonstrator noise and vibration flight test data are described as they relate to passenger cabin noise. The analyses were done to investigate the interior noise characteristics of advanced turboprop aircraft with aft-mounted engines, and to study the effectiveness of selected noise control treatments in reducing passenger cabin noise. The UHB Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB engine. For these tests, the UHB engine was a General Electric Unducted Fan, with either 8x8 or 10x8 counter-rotating propeller configurations. Interior noise level characteristics were studied for several altitudes and speeds, with emphasis on high altitude (35,000 ft), high speed (0.75 Mach) cruise conditions. The effectiveness of several noise control treatments was evaluated based on cabin noise measurements. The important airborne and structureborne transmission paths were identified for both tonal and broadband sources using the results of a sound intensity survey, exterior and interior noise and vibration data, and partial coherence analysis techniques. Estimates of the turbulent boundary layer pressure wavenumber-frequency spectrum were made, based on measured fuselage noise levels.

  10. UHB demonstrator interior noise control flight tests and analysis

    NASA Astrophysics Data System (ADS)

    Simpson, M. A.; Druez, P. M.; Kimbrough, A. J.; Brock, M. P.; Burge, P. L.; Mathur, G. P.; Cannon, M. R.; Tran, B. N.

    1989-10-01

    The measurement and analysis of MD-UHB (McDonnell Douglas Ultra High Bypass) Demonstrator noise and vibration flight test data are described as they relate to passenger cabin noise. The analyses were done to investigate the interior noise characteristics of advanced turboprop aircraft with aft-mounted engines, and to study the effectiveness of selected noise control treatments in reducing passenger cabin noise. The UHB Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB engine. For these tests, the UHB engine was a General Electric Unducted Fan, with either 8x8 or 10x8 counter-rotating propeller configurations. Interior noise level characteristics were studied for several altitudes and speeds, with emphasis on high altitude (35,000 ft), high speed (0.75 Mach) cruise conditions. The effectiveness of several noise control treatments was evaluated based on cabin noise measurements. The important airborne and structureborne transmission paths were identified for both tonal and broadband sources using the results of a sound intensity survey, exterior and interior noise and vibration data, and partial coherence analysis techniques. Estimates of the turbulent boundary layer pressure wavenumber-frequency spectrum were made, based on measured fuselage noise levels.

  11. Integrated Attitude Control Based on Momentum Management for Space Station

    NASA Astrophysics Data System (ADS)

    Zhou, Li-Ni

    An integrated attitude control for attitude control, momentum management and power storage is proposed as a momentum-management-based IPACS. The integrated attitude control combines ACMM and IPACS to guarantees the momentum of CMGs and flywheels within acceptable limits as well as satisfying the requirements of attitude control and power storage. The later objective is to testify the foundation of the integrated attitude control by the fact that the momentum management of the integrated attitude control is able to keep the momentum exchange actuators including flywheels and VSCMG out of singularity. Finally, the space station attitude control task during assembly process is illustrated to testify the effectiveness of the integrated attitude control.

  12. Model based control of dynamic atomic force microscope

    SciTech Connect

    Lee, Chibum; Salapaka, Srinivasa M.

    2015-04-15

    A model-based robust control approach is proposed that significantly improves imaging bandwidth for the dynamic mode atomic force microscopy. A model for cantilever oscillation amplitude and phase dynamics is derived and used for the control design. In particular, the control design is based on a linearized model and robust H{sub ∞} control theory. This design yields a significant improvement when compared to the conventional proportional-integral designs and verified by experiments.

  13. Model based control of dynamic atomic force microscope.

    PubMed

    Lee, Chibum; Salapaka, Srinivasa M

    2015-04-01

    A model-based robust control approach is proposed that significantly improves imaging bandwidth for the dynamic mode atomic force microscopy. A model for cantilever oscillation amplitude and phase dynamics is derived and used for the control design. In particular, the control design is based on a linearized model and robust H(∞) control theory. This design yields a significant improvement when compared to the conventional proportional-integral designs and verified by experiments. PMID:25933864

  14. Estimator Based Controller for High Speed Flywheel Magnetic Bearing System

    NASA Technical Reports Server (NTRS)

    Dever, Timothy P.; Brown, Gerald V.; Jansen, Ralph H.

    2002-01-01

    A flywheel system and its operator interface are described. Measurements of magnetic bearing negative stiffness are performed. Two digital magnetic bearing control algorithms (PD and estimator based) are defined and their implementations are described. Tuning of each controller is discussed. Comparison of the two controllers' stability, damping noise, and operating current are described. Results describing the superiority of the estimator-based controller are presented and discussed.

  15. Attainability analysis in stochastic controlled systems

    SciTech Connect

    Ryashko, Lev

    2015-03-10

    A control problem for stochastically forced nonlinear continuous-time systems is considered. We propose a method for construction of the regulator that provides a preassigned probabilistic distribution of random states in stochastic equilibrium. Geometric criteria of the controllability are obtained. Constructive technique for the specification of attainability sets is suggested.

  16. Orientation-Based Control of Microfluidics.

    PubMed

    Norouzi, Nazila; Bhakta, Heran C; Grover, William H

    2016-01-01

    Most microfluidic chips utilize off-chip hardware (syringe pumps, computer-controlled solenoid valves, pressure regulators, etc.) to control fluid flow on-chip. This expensive, bulky, and power-consuming hardware severely limits the utility of microfluidic instruments in resource-limited or point-of-care contexts, where the cost, size, and power consumption of the instrument must be limited. In this work, we present a technique for on-chip fluid control that requires no off-chip hardware. We accomplish this by using inert compounds to change the density of one fluid in the chip. If one fluid is made 2% more dense than a second fluid, when the fluids flow together under laminar flow the interface between the fluids quickly reorients to be orthogonal to Earth's gravitational force. If the channel containing the fluids then splits into two channels, the amount of each fluid flowing into each channel is precisely determined by the angle of the channels relative to gravity. Thus, any fluid can be routed in any direction and mixed in any desired ratio on-chip simply by holding the chip at a certain angle. This approach allows for sophisticated control of on-chip fluids with no off-chip control hardware, significantly reducing the cost of microfluidic instruments in point-of-care or resource-limited settings. PMID:26950700

  17. Orientation-Based Control of Microfluidics

    PubMed Central

    Norouzi, Nazila; Bhakta, Heran C.; Grover, William H.

    2016-01-01

    Most microfluidic chips utilize off-chip hardware (syringe pumps, computer-controlled solenoid valves, pressure regulators, etc.) to control fluid flow on-chip. This expensive, bulky, and power-consuming hardware severely limits the utility of microfluidic instruments in resource-limited or point-of-care contexts, where the cost, size, and power consumption of the instrument must be limited. In this work, we present a technique for on-chip fluid control that requires no off-chip hardware. We accomplish this by using inert compounds to change the density of one fluid in the chip. If one fluid is made 2% more dense than a second fluid, when the fluids flow together under laminar flow the interface between the fluids quickly reorients to be orthogonal to Earth’s gravitational force. If the channel containing the fluids then splits into two channels, the amount of each fluid flowing into each channel is precisely determined by the angle of the channels relative to gravity. Thus, any fluid can be routed in any direction and mixed in any desired ratio on-chip simply by holding the chip at a certain angle. This approach allows for sophisticated control of on-chip fluids with no off-chip control hardware, significantly reducing the cost of microfluidic instruments in point-of-care or resource-limited settings. PMID:26950700

  18. Controller design approach based on linear programming.

    PubMed

    Tanaka, Ryo; Shibasaki, Hiroki; Ogawa, Hiromitsu; Murakami, Takahiro; Ishida, Yoshihisa

    2013-11-01

    This study explains and demonstrates the design method for a control system with a load disturbance observer. Observer gains are determined by linear programming (LP) in terms of the Routh-Hurwitz stability criterion and the final-value theorem. In addition, the control model has a feedback structure, and feedback gains are determined to be the linear quadratic regulator. The simulation results confirmed that compared with the conventional method, the output estimated by our proposed method converges to a reference input faster when a load disturbance is added to a control system. In addition, we also confirmed the effectiveness of the proposed method by performing an experiment with a DC motor. PMID:23910155

  19. Total energy based flight control system

    NASA Technical Reports Server (NTRS)

    Lambregts, Antonius A. (Inventor)

    1985-01-01

    An integrated aircraft longitudinal flight control system uses a generalized thrust and elevator command computation (38), which accepts flight path angle, longitudinal acceleration command signals, along with associated feedback signals, to form energy rate error (20) and energy rate distribution error (18) signals. The engine thrust command is developed (22) as a function of the energy rate distribution error and the elevator position command is developed (26) as a function of the energy distribution error. For any vertical flight path and speed mode the outerloop errors are normalized (30, 34) to produce flight path angle and longitudinal acceleration commands. The system provides decoupled flight path and speed control for all control modes previously provided by the longitudinal autopilot, autothrottle and flight management systems.

  20. Average-cost based robust structural control

    NASA Technical Reports Server (NTRS)

    Hagood, Nesbitt W.

    1993-01-01

    A method is presented for the synthesis of robust controllers for linear time invariant structural systems with parameterized uncertainty. The method involves minimizing quantities related to the quadratic cost (H2-norm) averaged over a set of systems described by real parameters such as natural frequencies and modal residues. Bounded average cost is shown to imply stability over the set of systems. Approximations for the exact average are derived and proposed as cost functionals. The properties of these approximate average cost functionals are established. The exact average and approximate average cost functionals are used to derive dynamic controllers which can provide stability robustness. The robustness properties of these controllers are demonstrated in illustrative numerical examples and tested in a simple SISO experiment on the MIT multi-point alignment testbed.

  1. Rule-based fault-tolerant flight control

    NASA Technical Reports Server (NTRS)

    Handelman, Dave

    1988-01-01

    Fault tolerance has always been a desirable characteristic of aircraft. The ability to withstand unexpected changes in aircraft configuration has a direct impact on the ability to complete a mission effectively and safely. The possible synergistic effects of combining techniques of modern control theory, statistical hypothesis testing, and artificial intelligence in the attempt to provide failure accommodation for aircraft are investigated. This effort has resulted in the definition of a theory for rule based control and a system for development of such a rule based controller. Although presented here in response to the goal of aircraft fault tolerance, the rule based control technique is applicable to a wide range of complex control problems.

  2. Observer-based controller for nonlinear analytical systems

    NASA Astrophysics Data System (ADS)

    Elloumi, S.; Belhouane, M. M.; Benhadj Braiek, N.

    2016-06-01

    In this paper, we propose to design a polynomial observer-based control for nonlinear systems and to determine sufficient linear matrix inequality (LMI) global stabilisation conditions of the polynomial controlled system augmented by its observer. The design of the observer-based control leverages some notations from the Kronecker product and the power of matrices properties for the state space description of polynomial systems. The stability study of the polynomial controlled system augmented by its observer is based on the Lyapunov stability direct method. Intensive simulations are performed to illustrate the validity and the effectiveness of the polynomial approach used to design the control.

  3. Universal power transistor base drive control unit

    DOEpatents

    Gale, A.R.; Gritter, D.J.

    1988-06-07

    A saturation condition regulator system for a power transistor is disclosed which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition. 2 figs.

  4. Universal power transistor base drive control unit

    DOEpatents

    Gale, Allan R.; Gritter, David J.

    1988-01-01

    A saturation condition regulator system for a power transistor which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition.

  5. JAVA based LCD Reconstruction and Analysis Tools

    SciTech Connect

    Bower, G.

    2004-10-11

    We summarize the current status and future developments of the North American Group's Java-based system for studying physics and detector design issues at a linear collider. The system is built around Java Analysis Studio (JAS) an experiment-independent Java-based utility for data analysis. Although the system is an integrated package running in JAS, many parts of it are also standalone Java utilities.

  6. Neural network based optimal control of HVAC&R systems

    NASA Astrophysics Data System (ADS)

    Ning, Min

    Heating, Ventilation, Air-Conditioning and Refrigeration (HVAC&R) systems have wide applications in providing a desired indoor environment for different types of buildings. It is well acknowledged that 30%-40% of the total energy generated is consumed by buildings and HVAC&R systems alone account for more than 50% of the building energy consumption. Low operational efficiency especially under partial load conditions and poor control are part of reasons for such high energy consumption. To improve energy efficiency, HVAC&R systems should be properly operated to maintain a comfortable and healthy indoor environment under dynamic ambient and indoor conditions with the least energy consumption. This research focuses on the optimal operation of HVAC&R systems. The optimization problem is formulated and solved to find the optimal set points for the chilled water supply temperature, discharge air temperature and AHU (air handling unit) fan static pressure such that the indoor environment is maintained with the least chiller and fan energy consumption. To achieve this objective, a dynamic system model is developed first to simulate the system behavior under different control schemes and operating conditions. The system model is modular in structure, which includes a water-cooled vapor compression chiller model and a two-zone VAV system model. A fuzzy-set based extended transformation approach is then applied to investigate the uncertainties of this model caused by uncertain parameters and the sensitivities of the control inputs with respect to the interested model outputs. A multi-layer feed forward neural network is constructed and trained in unsupervised mode to minimize the cost function which is comprised of overall energy cost and penalty cost when one or more constraints are violated. After training, the network is implemented as a supervisory controller to compute the optimal settings for the system. In order to implement the optimal set points predicted by the

  7. Stability analysis of automobile driver steering control

    NASA Technical Reports Server (NTRS)

    Allen, R. W.

    1981-01-01

    In steering an automobile, the driver must basically control the direction of the car's trajectory (heading angle) and the lateral deviation of the car relative to a delineated pathway. A previously published linear control model of driver steering behavior which is analyzed from a stability point of view is considered. A simple approximate expression for a stability parameter, phase margin, is derived in terms of various driver and vehicle control parameters, and boundaries for stability are discussed. A field test study is reviewed that includes the measurement of driver steering control parameters. Phase margins derived for a range of vehicle characteristics are found to be generally consistent with known adaptive properties of the human operator. The implications of these results are discussed in terms of driver adaptive behavior.

  8. Analysis of inventory difference using fuzzy controllers

    SciTech Connect

    Zardecki, A.

    1994-08-01

    The principal objectives of an accounting system for safeguarding nuclear materials are as follows: (a) to provide assurance that all material quantities are present in the correct amount; (b) to provide timely detection of material loss; and (c) to estimate the amount of any loss and its location. In fuzzy control, expert knowledge is encoded in the form of fuzzy rules, which describe recommended actions for different classes of situations represented by fuzzy sets. The concept of a fuzzy controller is applied to the forecasting problem in a time series, specifically, to forecasting and detecting anomalies in inventory differences. This paper reviews the basic notion underlying the fuzzy control systems and provides examples of application. The well-known material-unaccounted-for diffusion plant data of Jaech are analyzed using both feedforward neural networks and fuzzy controllers. By forming a deference between the forecasted and observed signals, an efficient method to detect small signals in background noise is implemented.

  9. Calculation of the ELISA's cut-off based on the change-point analysis method for detection of Trypanosoma cruzi infection in Bolivian dogs in the absence of controls.

    PubMed

    Lardeux, Frédéric; Torrico, Gino; Aliaga, Claudia

    2016-07-01

    In ELISAs, sera of individuals infected by Trypanosoma cruzi show absorbance values above a cut-off value. The cut-off is generally computed by means of formulas that need absorbance readings of negative (and sometimes positive) controls, which are included in the titer plates amongst the unknown samples. When no controls are available, other techniques should be employed such as change-point analysis. The method was applied to Bolivian dog sera processed by ELISA to diagnose T. cruzi infection. In each titer plate, the change-point analysis estimated a step point which correctly discriminated among known positive and known negative sera, unlike some of the six usual cut-off formulas tested. To analyse the ELISAs results, the change-point method was as good as the usual cut-off formula of the form "mean + 3 standard deviation of negative controls". Change-point analysis is therefore an efficient alternative method to analyse ELISA absorbance values when no controls are available. PMID:27384081

  10. Tobacco control in the Russian Federation- a policy analysis

    PubMed Central

    2013-01-01

    Background The Russian Federation (Russia) has one of the highest smoking rates in the world. The purpose of this study is to analyze past and current trends of the tobacco epidemic in the Russian Federation, review current tobacco control policy responses, and identify areas of opportunity for policy priorities. Methods We used a policy triangle as analytical framework to examine content, context, and processes of Russian tobacco control policy. The analysis was based on secondary data on supply and demand sides of the Russian tobacco epidemic, tobacco-related economic and health effects during Russia’s economic transition, and compliance of Russian tobacco policy with international standards and regulations. Results Tobacco-promoting strategies have specifically targeted women and youth. Russia’s approval of a “National Tobacco Control Concept” and draft for a comprehensive tobacco control bill increasingly align national legislature with the WHO Framework Convention on Tobacco Control (FCTC). However, several structural and cultural factors represent substantial barriers to the policy process. The influence of transnational tobacco companies on policy processes in Russia has so far impeded a full implementation of the FCTC mandates. Conclusions Several strategies have been identified as having the potential to reduce the prevalence of tobacco use in Russia and decrease tobacco-related national health and economic burden: adjusting national tobacco policy by raising tobacco tax from the current lowest level in Europe to at least 70%; consequent enforcement of a complete smoking ban in public places; marketing restrictions; and smoking cessation interventions integrated into primary care. Russia’s tobacco control efforts need to target women and youths specifically to efficiently counter industry efforts. PMID:23339756

  11. Torque Ripple Reduction in Direct Torque Control Based Induction Motor using Intelligent Controllers

    NASA Astrophysics Data System (ADS)

    Sudhakar, Ambarapu; Vijaya Kumar, M.

    2015-09-01

    This paper presents intelligent control scheme together with conventional control scheme to overcome the problems with uncertainties in the structure encountered with classical model based design of induction motor drive based on direct torque control (DTC). It allows high dynamic performance to be obtained with very simple hysteresis control scheme. Direct control of the torque and flux is achieved by proper selection of inverter voltage space vector through a lookup table. This paper also presents the application of intelligent controllers like neural network and fuzzy logic controllers to control induction machines with DTC. Intelligent controllers are used to emulate the state selector of the DTC. With implementation of intelligent controllers the system is also verified and proved to be operated stably with reduced torque ripple. The proposed method validity and effectiveness has been verified by computer simulations using Matlab/Simulink®. These results are compared with the ones obtained with a classical DTC using proportional integral speed controller.

  12. Adaptive control based on retrospective cost optimization

    NASA Technical Reports Server (NTRS)

    Santillo, Mario A. (Inventor); Bernstein, Dennis S. (Inventor)

    2012-01-01

    A discrete-time adaptive control law for stabilization, command following, and disturbance rejection that is effective for systems that are unstable, MIMO, and/or nonminimum phase. The adaptive control algorithm includes guidelines concerning the modeling information needed for implementation. This information includes the relative degree, the first nonzero Markov parameter, and the nonminimum-phase zeros. Except when the plant has nonminimum-phase zeros whose absolute value is less than the plant's spectral radius, the required zero information can be approximated by a sufficient number of Markov parameters. No additional information about the poles or zeros need be known. Numerical examples are presented to illustrate the algorithm's effectiveness in handling systems with errors in the required modeling data, unknown latency, sensor noise, and saturation.

  13. Neural network based diagonal decoupling control of powered wheelchair systems.

    PubMed

    Nguyen, Tuan Nghia; Su, Steven; Nguyen, Hung T

    2014-03-01

    This paper proposes an advanced diagonal decoupling control method for powered wheelchair systems. This control method is based on a combination of the systematic diagonalization technique and the neural network control design. As such, this control method reduces coupling effects on a multivariable system, leading to independent control design procedures. Using an obtained dynamic model, the problem of the plant's Jacobian calculation is eliminated in a neural network control design. The effectiveness of the proposed control method is verified in a real-time implementation on a powered wheelchair system. The obtained results confirm that robustness and desired performance of the overall system are guaranteed, even under parameter uncertainty effects. PMID:23981543

  14. Towards a controlled sensitivity analysis of model development decisions

    NASA Astrophysics Data System (ADS)

    Clark, Martyn; Nijssen, Bart

    2016-04-01

    The current generation of hydrologic models have followed a myriad of different development paths, making it difficult for the community to test underlying hypotheses and identify a clear path to model improvement. Model comparison studies have been undertaken to explore model differences, but these studies have not been able to meaningfully attribute inter-model differences in predictive ability to individual model components because there are often too many structural and implementation differences among the models considered. As a consequence, model comparison studies to date have provided limited insight into the causes of differences in model behavior, and model development has often relied on the inspiration and experience of individual modelers rather than a systematic analysis of model shortcomings. This presentation will discuss a unified approach to process-based hydrologic modeling to enable controlled and systematic analysis of multiple model representations (hypotheses) of hydrologic processes and scaling behavior. Our approach, which we term the Structure for Unifying Multiple Modeling Alternatives (SUMMA), formulates a general set of conservation equations, providing the flexibility to experiment with different spatial representations, different flux parameterizations, different model parameter values, and different time stepping schemes. We will discuss the use of SUMMA to systematically analyze different model development decisions, focusing on both analysis of simulations for intensively instrumented research watersheds as well as simulations across a global dataset of FLUXNET sites. The intent of the presentation is to demonstrate how the systematic analysis of model shortcomings can help identify model weaknesses and inform future model development priorities.

  15. Relationship of Oct-4 to malignant stage: a meta-analysis based on 502 positive/high Oct-4 cases and 522 negative/low case-free controls

    PubMed Central

    Zheng, Fangfang; Zheng, Xiaobin; Huang, Rijiao; Yang, Weilin; Chen, Zhenguang

    2016-01-01

    Background Octamer 4 (Oct-4), an important member of the POU domain transcription factor family, has been suggested to function as a master switch during differentiation of human somatic cells and more recently has come to be linked with neoplastic properties. The aim of this study was to evaluate the relationship between Oct-4 and cancer stage using a meta-analysis approach. Materials and Methods Relevant articles published as of May 2015 were retrieved from the following databases: PubMed, ISI Web of Knowledge, Embase, and Chinese National Knowledge Infrastructure (CNKI). The strengths of relationship for outcomes of interest were estimated based on odds ratios (ORs) and 95% confidence intervals (CIs). Results A total of 11 articles on Oct-4 and cancer staging that collectively included 502 positive/high Oct-4 cases and 522 negative/low case-free controls were chosen. Positive/high Oct-4 was significantly associated with cancer stage in several kinds of cancer. Specifically, positive/high Oct-4 was associated with cancer stage III/IV (fixed effects: OR = 1.53, 95% CI = 1.12–2.10), primary tumor (T3–4) (random effects: OR = 1.93, 95% CI = 0.99–3.77), and cancer grade of differentiation (intermediate-poor) (random effects: OR = 3.45, 95% CI = 1.5–7.61). Conclusion These findings suggest that positive/high Oct-4 is more strongly linked to stage III/IV cancer and cancer grade of differentiation, and is correlated with malignant characteristics that lead to poor prognosis in different types of cancer, especially in Asian. Given variability related to ethnicity and differences in cancer types, additional studies are warranted to establish the generalizability of our findings. PMID:26575328

  16. Analysis of the impact of controlled release formulations on oral drug absorption, gut wall metabolism and relative bioavailability of CYP3A substrates using a physiologically-based pharmacokinetic model.

    PubMed

    Olivares-Morales, Andrés; Kamiyama, Yoshiteru; Darwich, Adam S; Aarons, Leon; Rostami-Hodjegan, Amin

    2015-01-25

    Controlled release (CR) formulations are usually designed to achieve similar exposure (AUC) levels as the marketed immediate release (IR) formulation. However, the AUC is often lower following CR compared to IR formulations. There are a few exceptions when the CR formulations have shown higher AUC. This study investigated the impact of CR formulations on oral drug absorption and CYP3A4-mediated gut wall metabolism. A review of the current literature on relative bioavailability (Frel) between CR and IR formulations of CYP3A substrates was conducted. This was followed by a systematic analysis to assess the impact of the release characteristics and the drug-specific factors (including metabolism and permeability) on oral bioavailability employing a physiologically-based pharmacokinetic (PBPK) modelling and simulation approach. From the literature review, only three CYP3A4 substrates showed higher Frel when formulated as CR. Several scenarios were investigated using the PBPK approach; in most of them, the oral absorption of CR formulations was lower as compared to the IR formulations. However, for highly permeable compounds that were CYP3A4 substrates the reduction in absorption was compensated by an increase in the fraction that escapes from first pass metabolism in the gut wall (FG), where the magnitude was dependent on CYP3A4 affinity. The systematic simulations of various interplays between different parameters demonstrated that BCS class 1 highly-cleared CYP3A4 substrates can display up to 220% higher relative bioavailability when formulated as CR compared to IR, in agreement with the observed data collected from the literature. The results and methodology of this study can be employed during the formulation development process in order to optimize drug absorption, especially for CYP3A4 substrates. PMID:25444842

  17. Analysis of Alternative Mercury Control Strategies

    EIA Publications

    2005-01-01

    This analysis responds to a September 14, 2004, request from Chairmen James M. Inhofe and George V. Voinovich asking the Energy Information Administration (EIA) to analyze the impacts of different approaches for removing mercury from coal-fired power plants.

  18. An Analysis of the Control Hierarchy Modelling of the CMS Detector Control System

    NASA Astrophysics Data System (ADS)

    Hwong, Yi Ling; Willemse, Tim; Kusters, Vincent; Bauer, Gerry; Beccati, Barbara; Behrens, Ulf; Biery, Kurt; Bouffet, Olivier; Branson, James; Bukowiec, Sebastian; Cano, Eric; Cheung, Harry; Ciganek, Marek; Cittolin, Sergio; Coarasa, Jose Antonio; Deldicque, Christian; Dupont, Aymeric; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gomez-Reino, Robert; Holzner, Andre; Hatton, Derek; Masetti, Lorenzo; Meijers, Frans; Meschi, Emilio; Mommsen, Remigius K.; Moser, Roland; O'Dell, Vivian; Orsini, Luciano; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Raginel, Olivier; Sakulin, Hannes; Sani, Matteo; Schieferdeckerb, Philipp; Schwick, Christoph; Shpakov, Dennis; Simon, Michal; Sumorok, Konstanty

    2011-12-01

    The supervisory level of the Detector Control System (DCS) of the CMS experiment is implemented using Finite State Machines (FSM), which model the behaviours and control the operations of all the sub-detectors and support services. The FSM tree of the whole CMS experiment consists of more than 30.000 nodes. An analysis of a system of such size is a complex task but is a crucial step towards the improvement of the overall performance of the FSM system. This paper presents the analysis of the CMS FSM system using the micro Common Representation Language 2 (mcrl2) methodology. Individual mCRL2 models are obtained for the FSM systems of the CMS sub-detectors using the ASF+SDF automated translation tool. Different mCRL2 operations are applied to the mCRL2 models. A mCRL2 simulation tool is used to closer examine the system. Visualization of a system based on the exploration of its state space is enabled with a mCRL2 tool. Requirements such as command and state propagation are expressed using modal mu-calculus and checked using a model checking algorithm. For checking local requirements such as endless loop freedom, the Bounded Model Checking technique is applied. This paper discusses these analysis techniques and presents the results of their application on the CMS FSM system.

  19. Spacelab data analysis and interactive control study

    NASA Technical Reports Server (NTRS)

    Tarbell, T. D.; Drake, J. F.

    1980-01-01

    The study consisted of two main tasks, a series of interviews of Spacelab users and a survey of data processing and display equipment. Findings from the user interviews on questions of interactive control, downlink data formats, and Spacelab computer software development are presented. Equipment for quick look processing and display of scientific data in the Spacelab Payload Operations Control Center (POCC) was surveyed. Results of this survey effort are discussed in detail, along with recommendations for NASA development of several specific display systems which meet common requirements of many Spacelab experiments.

  20. Knowledge base for expert system process control/optimization

    NASA Astrophysics Data System (ADS)

    Lee, C. W.; Abrams, Frances L.

    An expert system based on the philosophy of qualitative process automation has been developed for the autonomous cure cycle development and control of the autoclave curing process. The system's knowledge base in the form of declarative rules is based on the qualitative understanding of the curing process. The knowledge base and examples of the resulting cure cycle are presented.

  1. A multi-mode operation control strategy for flexible microgrid based on sliding-mode direct voltage and hierarchical controls.

    PubMed

    Zhang, Qinjin; Liu, Yancheng; Zhao, Youtao; Wang, Ning

    2016-03-01

    Multi-mode operation and transient stability are two problems that significantly affect flexible microgrid (MG). This paper proposes a multi-mode operation control strategy for flexible MG based on a three-layer hierarchical structure. The proposed structure is composed of autonomous, cooperative, and scheduling controllers. Autonomous controller is utilized to control the performance of the single micro-source inverter. An adaptive sliding-mode direct voltage loop and an improved droop power loop based on virtual negative impedance are presented respectively to enhance the system disturbance-rejection performance and the power sharing accuracy. Cooperative controller, which is composed of secondary voltage/frequency control and phase synchronization control, is designed to eliminate the voltage/frequency deviations produced by the autonomous controller and prepare for grid connection. Scheduling controller manages the power flow between the MG and the grid. The MG with the improved hierarchical control scheme can achieve seamless transitions from islanded to grid-connected mode and have a good transient performance. In addition the presented work can also optimize the power quality issues and improve the load power sharing accuracy between parallel VSIs. Finally, the transient performance and effectiveness of the proposed control scheme are evaluated by theoretical analysis and simulation results. PMID:26686458

  2. A Voting Protocol Based on the Controlled Quantum Operation Teleportation

    NASA Astrophysics Data System (ADS)

    Tian, Juan-Hong; Zhang, Jian-Zhong; Li, Yan-Ping

    2016-05-01

    Based on the controlled quantum operation teleportation, a secure voting protocol is proposed in this paper. Genuine four-qubit entangled state functions as the quantum channel. The eligible voter's quantum operation which represents his vote information can be transmitted to the tallyman Bob with the help of the scrutineer Charlie. Voter's quantum identity authentication provides the anonymity of voters'ID, which is ensured by a zero-knowledge proof of the notary organization CA. Charlie's supervision in the whole voting process can make the protocol satisfy verifiability and non-reusability so as to avoid Bob's dishonest behaviour. The security analysis shows that the voting protocol satisfies unforgeability, and has great advantages over some relevant researches. Additionally, the quantum operation can be transmitted successfully with the probability 1, which can make the protocol reliable and practical.

  3. An interferometer-based phase control system

    NASA Technical Reports Server (NTRS)

    Ott, J. H.; Rice, J. S.

    1981-01-01

    A system for focusing and pointing the SPS power beam is discussed. The system is ground based and closed loop. One receiving antenna is required on earth. A conventional uplinked data channel transmits an 8-bit phase error correction back to the SPS for sequential calibration of each power module. Beam pointing resolution is better than 140 meters at the rectenna.

  4. An interferometer-based phase control system

    NASA Technical Reports Server (NTRS)

    Ott, J. H.; Rice, J. S.

    1980-01-01

    A system for focusing and pointing the SPS power beam is discussed. The system is ground based and closed loop. One receiving antenna is required on Earth. A conventional uplink data channel transmits an 8-bit phase error correlation back to the SPS for sequential calibration of each power module. Beam pointing resolution is better than 140 meters at the Rectenna.

  5. Data-Based Predictive Control with Multirate Prediction Step

    NASA Technical Reports Server (NTRS)

    Barlow, Jonathan S.

    2010-01-01

    Data-based predictive control is an emerging control method that stems from Model Predictive Control (MPC). MPC computes current control action based on a prediction of the system output a number of time steps into the future and is generally derived from a known model of the system. Data-based predictive control has the advantage of deriving predictive models and controller gains from input-output data. Thus, a controller can be designed from the outputs of complex simulation code or a physical system where no explicit model exists. If the output data happens to be corrupted by periodic disturbances, the designed controller will also have the built-in ability to reject these disturbances without the need to know them. When data-based predictive control is implemented online, it becomes a version of adaptive control. One challenge of MPC is computational requirements increasing with prediction horizon length. This paper develops a closed-loop dynamic output feedback controller that minimizes a multi-step-ahead receding-horizon cost function with multirate prediction step. One result is a reduced influence of prediction horizon and the number of system outputs on the computational requirements of the controller. Another result is an emphasis on portions of the prediction window that are sampled more frequently. A third result is the ability to include more outputs in the feedback path than in the cost function.

  6. Effect of hand-based sensors on manipulator control performance

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.

    1977-01-01

    Manipulator task categories and motion phases require various hand-based information systems to meet the control performance requirements. The effect of proximity, tactile and force/torque sensors on the performance of remote manipulator control is discussed. An overview is presented on various experimental hand-based information systems which provide the manipulator controller some non-visual 'awareness' of the task environment. The rest of the paper describes and evaluates various control experiments performed at JPL using hand-mounted proximity sensors to guide and control hand motion near solid objects.

  7. HIV control in vivo: Dynamical analysis

    NASA Astrophysics Data System (ADS)

    Gumel, A. B.; Moghadas, S. M.

    2004-10-01

    A deterministic model for the immunological and therapeutic control of human immunodeficiency virus (HIV) in vivo is studied qualitatively. In addition to analyzing the local stability of the equilibria, the global stability of the infection-free equilibrium is established. The optimal efficacy level of anti-retroviral therapy needed to eradicate HIV from the body of an HIV-infected individual is obtained.

  8. Using social network analysis to inform disease control interventions.

    PubMed

    Marquetoux, Nelly; Stevenson, Mark A; Wilson, Peter; Ridler, Anne; Heuer, Cord

    2016-04-01

    Contact patterns between individuals are an important determinant for the spread of infectious diseases in populations. Social network analysis (SNA) describes contact patterns and thus indicates how infectious pathogens may be transmitted. Here we explore network characteristics that may inform the development of disease control programes. This study applies SNA methods to describe a livestock movement network of 180 farms in New Zealand from 2006 to 2010. We found that the number of contacts was overall consistent from year to year, while the choice of trading partners tended to vary. This livestock movement network illustrated how a small number of farms central to the network could play a potentially dominant role for the spread of infection in this population. However, fragmentation of the network could easily be achieved by "removing" a small proportion of farms serving as bridges between otherwise isolated clusters, thus decreasing the probability of large epidemics. This is the first example of a comprehensive analysis of pastoral livestock movements in New Zealand. We conclude that, for our system, recording and exploiting livestock movements can contribute towards risk-based control strategies to prevent and monitor the introduction and the spread of infectious diseases in animal populations. PMID:26883965

  9. Calculation of the ELISA’s cut-off based on the change-point analysis method for detection of Trypanosoma cruzi infection in Bolivian dogs in the absence of controls

    PubMed Central

    Lardeux, Frédéric; Torrico, Gino; Aliaga, Claudia

    2016-01-01

    In ELISAs, sera of individuals infected by Trypanosoma cruzi show absorbance values above a cut-off value. The cut-off is generally computed by means of formulas that need absorbance readings of negative (and sometimes positive) controls, which are included in the titer plates amongst the unknown samples. When no controls are available, other techniques should be employed such as change-point analysis. The method was applied to Bolivian dog sera processed by ELISA to diagnose T. cruzi infection. In each titer plate, the change-point analysis estimated a step point which correctly discriminated among known positive and known negative sera, unlike some of the six usual cut-off formulas tested. To analyse the ELISAs results, the change-point method was as good as the usual cut-off formula of the form “mean + 3 standard deviation of negative controls”. Change-point analysis is therefore an efficient alternative method to analyse ELISA absorbance values when no controls are available. PMID:27384081

  10. An expert system based intelligent control scheme for space bioreactors

    NASA Technical Reports Server (NTRS)

    San, Ka-Yiu

    1988-01-01

    An expert system based intelligent control scheme is being developed for the effective control and full automation of bioreactor systems in space. The scheme developed will have the capability to capture information from various resources including heuristic information from process researchers and operators. The knowledge base of the expert system should contain enough expertise to perform on-line system identification and thus be able to adapt the controllers accordingly with minimal human supervision.

  11. Robust Mediation Analysis Based on Median Regression

    PubMed Central

    Yuan, Ying; MacKinnon, David P.

    2014-01-01

    Mediation analysis has many applications in psychology and the social sciences. The most prevalent methods typically assume that the error distribution is normal and homoscedastic. However, this assumption may rarely be met in practice, which can affect the validity of the mediation analysis. To address this problem, we propose robust mediation analysis based on median regression. Our approach is robust to various departures from the assumption of homoscedasticity and normality, including heavy-tailed, skewed, contaminated, and heteroscedastic distributions. Simulation studies show that under these circumstances, the proposed method is more efficient and powerful than standard mediation analysis. We further extend the proposed robust method to multilevel mediation analysis, and demonstrate through simulation studies that the new approach outperforms the standard multilevel mediation analysis. We illustrate the proposed method using data from a program designed to increase reemployment and enhance mental health of job seekers. PMID:24079925

  12. Control Statistics Process Data Base V4

    Energy Science and Technology Software Center (ESTSC)

    1998-05-07

    The check standard database program, CSP_CB, is a menu-driven program that can acquire measurement data for check standards having a parameter dependence (such as frequency) or no parameter dependence (for example, mass measurements). The program may be run stand-alone or leaded as a subprogram to a Basic program already in memory. The software was designed to require little additional work on the part of the user. The facilitate this design goal, the program is entirelymore » menu-driven. In addition, the user does have control of file names and parameters within a definition file which sets up the basic scheme of file names.« less

  13. Space Station Environment Control and Life Support System Pressure Control Pump Assembly Modeling and Analysis

    NASA Technical Reports Server (NTRS)

    Schunk, R. Gregory

    2002-01-01

    This paper presents the Modeling and Analysis of the Space Station Environment Control and Life Support System Pressure Control Pump Assembly (PCPA). The contents include: 1) Integrated PCPA/Manifold Analyses; 2) Manifold Performance Analysis; 3) PCPA Motor Heat Leak Study; and 4) Future Plans. This paper is presented in viewgraph form.

  14. Dynamic Curvature Steering Control for Autonomous Vehicle: Performance Analysis

    NASA Astrophysics Data System (ADS)

    Aizzat Zakaria, Muhammad; Zamzuri, Hairi; Amri Mazlan, Saiful

    2016-02-01

    This paper discusses the design of dynamic curvature steering control for autonomous vehicle. The lateral control and longitudinal control are discussed in this paper. The controller is designed based on the dynamic curvature calculation to estimate the path condition and modify the vehicle speed and steering wheel angle accordingly. In this paper, the simulation results are presented to show the capability of the controller to track the reference path. The controller is able to predict the path and modify the vehicle speed to suit the path condition. The effectiveness of the controller is shown in this paper whereby identical performance is achieved with the benchmark but with extra curvature adaptation capabilites.

  15. Transition from Persistent to Anti-Persistent Correlations in Postural Sway Indicates Velocity-Based Control

    PubMed Central

    Delignières, Didier; Torre, Kjerstin; Bernard, Pierre-Louis

    2011-01-01

    The displacement of the center-of-pressure (COP) during quiet stance has often been accounted for by the control of COP position dynamics. In this paper, we discuss the conclusions drawn from previous analyses of COP dynamics using fractal-related methods. On the basis of some methodological clarification and the analysis of experimental data using stabilogram diffusion analysis, detrended fluctuation analysis, and an improved version of spectral analysis, we show that COP velocity is typically bounded between upper and lower limits. We argue that the hypothesis of an intermittent velocity-based control of posture is more relevant than position-based control. A simple model for COP velocity dynamics, based on a bounded correlated random walk, reproduces the main statistical signatures evidenced in the experimental series. The implications of these results are discussed. PMID:21390333

  16. Spacecraft attitude control momentum requirements analysis

    NASA Technical Reports Server (NTRS)

    Robertson, Brent P.; Heck, Michael L.

    1987-01-01

    The relationship between attitude and angular momentum control requirements is derived for a fixed attitude, Earth orbiting spacecraft with large area articulating appendages. Environmental effects such as gravity gradient, solar radiation pressure, and aerodynamic forces arising from a dynamic, rotating atmosphere are examined. It is shown that, in general, each environmental effect contributes to both cyclic and secular momentum requirements both within and perpendicular to the orbit plane. The gyroscopic contribution to the angular momentum control requirements resulting from a rotating, Earth oriented spacecraft is also discussed. Special conditions are described where one or more components of the angular momentum can be made to vanish, or become purely cyclical. Computer generated plots for a candidate space station configuration are presented to supplement the analytically derived results.

  17. Magnetic field regulation control system analysis

    SciTech Connect

    Badelt, Steven W.

    1996-05-01

    This study comprises (1) an analytical characterization of the Cameca ion microscope`s magnetic field regulation circuitry and (2) comparisons between the analytical predictions and the measured performance of the control system. It is the first step in a project to achieve routine field regulation better than 10ppm. The control loop was decomposed into functional subcircuits and simulated in SPICE to determine DC, AC, and transient response. Transfer functions were extracted from SPICE, simplified, and analyzed in MATLAB. Both SPICE and MATLAB simulations were calculated for step inputs, and these results were compared to actual measurements. Magnetic field fluctuations were measured at high mass resolving power. The frequency spectrum of the fluctuations was analyzed by FFT. Difficulties encountered and implications for future work are discussed.

  18. Information fusion based optimal control for large civil aircraft system.

    PubMed

    Zhen, Ziyang; Jiang, Ju; Wang, Xinhua; Gao, Chen

    2015-03-01

    Wind disturbance has a great influence on landing security of Large Civil Aircraft. Through simulation research and engineering experience, it can be found that PID control is not good enough to solve the problem of restraining the wind disturbance. This paper focuses on anti-wind attitude control for Large Civil Aircraft in landing phase. In order to improve the riding comfort and the flight security, an information fusion based optimal control strategy is presented to restrain the wind in landing phase for maintaining attitudes and airspeed. Data of Boeing707 is used to establish a nonlinear mode with total variables of Large Civil Aircraft, and then two linear models are obtained which are divided into longitudinal and lateral equations. Based on engineering experience, the longitudinal channel adopts PID control and C inner control to keep longitudinal attitude constant, and applies autothrottle system for keeping airspeed constant, while an information fusion based optimal regulator in the lateral control channel is designed to achieve lateral attitude holding. According to information fusion estimation, by fusing hard constraint information of system dynamic equations and the soft constraint information of performance index function, optimal estimation of the control sequence is derived. Based on this, an information fusion state regulator is deduced for discrete time linear system with disturbance. The simulation results of nonlinear model of aircraft indicate that the information fusion optimal control is better than traditional PID control, LQR control and LQR control with integral action, in anti-wind disturbance performance in the landing phase. PMID:25440950

  19. Engine control system having speed-based timing

    DOEpatents

    Willi, Martin L.; Fiveland, Scott B.; Montgomery, David T.; Gong, Weidong

    2012-02-14

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

  20. Fuzzy decoupling controller based on multimode control algorithm of PI-single neuron and its application

    NASA Astrophysics Data System (ADS)

    Zhang, Xianxia; Wang, Jian; Qin, Tinggao

    2003-09-01

    Intelligent control algorithms are introduced into the control system of temperature and humidity. A multi-mode control algorithm of PI-Single Neuron is proposed for single loop control of temperature and humidity. In order to remove the coupling between temperature and humidity, a new decoupling method is presented, which is called fuzzy decoupling. The decoupling is achieved by using a fuzzy controller that dynamically modifies the static decoupling coefficient. Taking the control algorithm of PI-Single Neuron as the single loop control of temperature and humidity, the paper provides the simulated output response curves with no decoupling control, static decoupling control and fuzzy decoupling control. Those control algorithms are easily implemented in singlechip-based hardware systems.

  1. Rule-based analysis of pilot decisions

    NASA Technical Reports Server (NTRS)

    Lewis, C. M.

    1985-01-01

    The application of the rule identification technique to the analysis of human performance data is proposed. The relation between the language and identifiable consistencies is discussed. The advantages of production system models for the description of complex human behavior are studied. The use of a Monte Carlo significance testing procedure to assure the validity of the rule identification is examined. An example of the rule-based analysis of Palmer's (1983) data is presented.

  2. Synchronization analysis and control of three eccentric rotors in a vibrating system using adaptive sliding mode control algorithm

    NASA Astrophysics Data System (ADS)

    Kong, Xiangxi; Zhang, Xueliang; Chen, Xiaozhe; Wen, Bangchun; Wang, Bo

    2016-05-01

    In this paper, self- and controlled synchronizations of three eccentric rotors (ERs) in line driven by induction motors rotating in the same direction in a vibrating system are investigated. The vibrating system is a typical underactuated mechanical-electromagnetic coupling system. The analysis and control of the vibrating system convert to the synchronization motion problem of three ERs. Firstly, the self-synchronization motion of three ERs is analyzed according to self-synchronization theory. The criterions of synchronization and stability of self-synchronous state are obtained by using a modified average perturbation method. The significant synchronization motion of three ERs with zero phase differences cannot be implemented according to self-synchronization theory through analysis and simulations. To implement the synchronization motion of three ERs with zero phase differences, an adaptive sliding mode control (ASMC) algorithm based on a modified master-slave control strategy is employed to design the controllers. The stability of the controllers is verified by using Lyapunov theorem. The performances of the controlled synchronization system are presented by simulations to demonstrate the effectiveness of controllers. Finally, the effects of reference speed and non-zero phase differences on the controlled system are discussed to show the strong robustness of the proposed controllers. Additionally, the dynamic responses of the vibrating system in different synchronous states are analyzed.

  3. Extended State Observer based control for coaxial-rotor UAV.

    PubMed

    Rida Mokhtari, M; Choukchou Braham, Amal; Cherki, Brahim

    2016-03-01

    This paper considers the problem of controlling the position and the orientation of a Coaxial-Rotor Unmanned Aerial Vehicle -CRUAV- despite unknown aerodynamic efforts. A hierarchical flight controller is designed, allowing the trajectory tracking and the stabilization of the vehicle. The designed controller is build through a hierarchical approach yielding two control loops, an inner one to control the attitude and an outer one to control the translational trajectory of the rotorcraft. An Extended State Observer -ESO- is used to estimate the state and the unknown aerodynamic disturbances. 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. PMID:26708305

  4. Camera-Based Control for Industrial Robots Using OpenCV Libraries

    NASA Astrophysics Data System (ADS)

    Seidel, Patrick A.; Böhnke, Kay

    This paper describes a control system for industrial robots whose reactions base on the analysis of images provided by a camera mounted on top of the robot. We show that such control system can be designed and implemented with an open source image processing library and cheap hardware. Using one specific robot as an example, we demonstrate the structure of a possible control algorithm running on a PC and its interaction with the robot.

  5. Data acquisition, control, and analysis for the Argonne Advanced Accelerator Test Facility (AATF)

    SciTech Connect

    Schoessow, P.

    1989-01-01

    The AATF has been used to study wakefield acceleration and focusing in plasmas and rf structures. A PC-based system is described which incorporates the functions of beamline control and acquisition, storage, and preliminary analysis of video images from luminescent screen beam diagnostics. General features of the offline analysis of wakefield data are also discussed. 4 refs., 3 figs.

  6. Highly accurate coating composition control during co-sputtering, based on controlling plasma chromaticity

    SciTech Connect

    Anguita, J.V.; Thwaites, M.; Holton, B.; Hockley, P.; Holton, B.; Rand, S.

    2005-03-01

    Highly accurate control of sputtering processes is of paramount importance to industry. Plasma diagnostic equipment based on spectroscopic methods such as optical emission spectroscopy (OES) have been commercially available for many years and have the ability to deliver a high level of accuracy. Despite this, their complexity, demand for operator time, and disregard for the vast majority of the optical emission spectrum have rendered them as unpopular, and they are rarely used in manufacturing lines. This article introduces the measurement of the chromaticity of the plasma as a new method of analysis, as an alternative to OES. This method is simple, while maintaining a high level of sensitivity. Chromaticity monitors a wide range of the optical emission spectrum, obtaining a large amount of process information. It also averages and simplifies the data, making them easier to analyze.

  7. Transaction-Based Building Controls Framework, Volume 1: Reference Guide

    SciTech Connect

    Somasundaram, Sriram; Pratt, Robert G.; Akyol, Bora A.; Fernandez, Nicholas; Foster, Nikolas AF; Katipamula, Srinivas; Mayhorn, Ebony T.; Somani, Abhishek; Steckley, Andrew C.; Taylor, Zachary T.

    2014-04-28

    This document proposes a framework concept to achieve the objectives of raising buildings’ efficiency and energy savings potential benefitting building owners and operators. We call it a transaction-based framework, wherein mutually-beneficial and cost-effective market-based transactions can be enabled between multiple players across different domains. Transaction-based building controls are one part of the transactional energy framework. While these controls realize benefits by enabling automatic, market-based intra-building efficiency optimizations, the transactional energy framework provides similar benefits using the same market -based structure, yet on a larger scale and beyond just buildings, to the society at large.

  8. Rate-Based Model Predictive Control of Turbofan Engine Clearance

    NASA Technical Reports Server (NTRS)

    DeCastro, Jonathan A.

    2006-01-01

    An innovative model predictive control strategy is developed for control of nonlinear aircraft propulsion systems and sub-systems. At the heart of the controller is a rate-based linear parameter-varying model that propagates the state derivatives across the prediction horizon, extending prediction fidelity to transient regimes where conventional models begin to lose validity. The new control law is applied to a demanding active clearance control application, where the objectives are to tightly regulate blade tip clearances and also anticipate and avoid detrimental blade-shroud rub occurrences by optimally maintaining a predefined minimum clearance. Simulation results verify that the rate-based controller is capable of satisfying the objectives during realistic flight scenarios where both a conventional Jacobian-based model predictive control law and an unconstrained linear-quadratic optimal controller are incapable of doing so. The controller is evaluated using a variety of different actuators, illustrating the efficacy and versatility of the control approach. It is concluded that the new strategy has promise for this and other nonlinear aerospace applications that place high importance on the attainment of control objectives during transient regimes.

  9. A Novel Control algorithm based DSTATCOM for Load Compensation

    NASA Astrophysics Data System (ADS)

    R, Sreejith; Pindoriya, Naran M.; Srinivasan, Babji

    2015-11-01

    Distribution Static Compensator (DSTATCOM) has been used as a custom power device for voltage regulation and load compensation in the distribution system. Controlling the switching angle has been the biggest challenge in DSTATCOM. Till date, Proportional Integral (PI) controller is widely used in practice for load compensation due to its simplicity and ability. However, PI Controller fails to perform satisfactorily under parameters variations, nonlinearities, etc. making it very challenging to arrive at best/optimal tuning values for different operating conditions. Fuzzy logic and neural network based controllers require extensive training and perform better under limited perturbations. Model predictive control (MPC) is a powerful control strategy, used in the petrochemical industry and its application has been spread to different fields. MPC can handle various constraints, incorporate system nonlinearities and utilizes the multivariate/univariate model information to provide an optimal control strategy. Though it finds its application extensively in chemical engineering, its utility in power systems is limited due to the high computational effort which is incompatible with the high sampling frequency in these systems. In this paper, we propose a DSTATCOM based on Finite Control Set Model Predictive Control (FCS-MPC) with Instantaneous Symmetrical Component Theory (ISCT) based reference current extraction is proposed for load compensation and Unity Power Factor (UPF) action in current control mode. The proposed controller performance is evaluated for a 3 phase, 3 wire, 415 V, 50 Hz distribution system in MATLAB Simulink which demonstrates its applicability in real life situations.

  10. Personal Computer Based Controller For Switched Reluctance Motor Drives

    NASA Astrophysics Data System (ADS)

    Mang, X.; Krishnan, R.; Adkar, S.; Chandramouli, G.

    1987-10-01

    Th9, switched reluctance motor (SRM) has recently gained considerable attention in the variable speed drive market. Two important factors that have contributed to this are, the simplicity of construction and the possibility of developing low cost con-trollers with minimum number of switching devices in the drive circuits. This is mainly due to the state-of-art of the present digital circuits technology and the low cost of switching devices. The control of this motor drive is under research. Optimized performance of the SRM motor drive is very dependent on the integration of the controller, converter and the motor. This research on system integration involves considerable changes in the control algorithms and their implementation. A Personal computer (PC) based controller is very appropriate for this purpose. Accordingly, the present paper is concerned with the design of a PC based controller for a SRM. The PC allows for real-time microprocessor control with the possibility of on-line system parameter modifications. Software reconfiguration of this controller is easier than a hardware based controller. User friendliness is a natural consequence of such a system. Considering the low cost of PCs, this controller will offer an excellent cost-effective means of studying the control strategies for the SRM drive intop greater detail than in the past.

  11. Effects of Locus of Control and Learner-Control on Web-Based Language Learning

    ERIC Educational Resources Information Center

    Chang, Mei-Mei; Ho, Chiung-Mei

    2009-01-01

    The study explored the effects of students' locus of control and types of control over instruction on their self-efficacy and performance in a web-based language learning environment. A web-based interactive instructional program focusing on the comprehension of news articles for English language learners was developed in two versions: learner-…

  12. An averaging analysis of discrete-time indirect adaptive control

    NASA Technical Reports Server (NTRS)

    Phillips, Stephen M.; Kosut, Robert L.; Franklin, Gene F.

    1988-01-01

    An averaging analysis of indirect, discrete-time, adaptive control systems is presented. The analysis results in a signal-dependent stability condition and accounts for unmodeled plant dynamics as well as exogenous disturbances. This analysis is applied to two discrete-time adaptive algorithms: an unnormalized gradient algorithm and a recursive least-squares (RLS) algorithm with resetting. Since linearization and averaging are used for the gradient analysis, a local stability result valid for small adaptation gains is found. For RLS with resetting, the assumption is that there is a long time between resets. The results for the two algorithms are virtually identical, emphasizing their similarities in adaptive control.

  13. Robust power system controller design based on measured models

    SciTech Connect

    Fatehi, F.; Smith, J.R.; Pierre, D.A.

    1996-05-01

    This paper presents combined system identification and controller design methods to dampen low-frequency oscillations in multimachine power systems. An iterative closed-loop identification method is used to find a linear model for the power system. Linear quadratic Gaussian controller design with loop transfer recovery (LQG/LTR), based on a generalized technique for the nonminimum phase (NMP) power system model, is used to design controllers. Simulation results are presented to demonstrate the robustness of controllers based on closed-loop identified plant models and the amount of loop transfer recovery that is possible for NMP plant models.

  14. Control of large antennas based on electromagnetic performance criteria

    NASA Technical Reports Server (NTRS)

    Lin, Y. H.; Hamidi, M.; Manshadi, M.

    1985-01-01

    The electromagnetic (EM) performance of large flexible antennas is traditionally achieved by imposing stringent geometric restrictions on the structural distortions from a nominal optimum configuration. An approach to alleviate the stringency of the geometrical criteria of satisfactory performance is presented. The approach consists of generating a linear optimal control problem with quadratic cost functional where the cost functional is obtained from the EM characteristics of the antenna and the dynamic system constraint is given by the structural model of the antenna. It is established that the EM based optimal controller is considerably more efficient than the traditional geometrical based controllers. The same EM performance can be achieved with a much reduced control effort.

  15. Engine control system having fuel-based adjustment

    DOEpatents

    Willi, Martin L.; Fiveland, Scott B.; Montgomery, David T.; Gong, Weidong

    2011-03-15

    A control system for an engine having a cylinder is disclosed having an engine valve configured to affect a fluid flow of the cylinder, an actuator configured to move the engine valve, and an in-cylinder sensor configured to generate a signal indicative of a characteristic of fuel entering the cylinder. The control system also has a controller in communication with the actuator and the sensor. The controller is configured to determine the characteristic of the fuel based on the signal and selectively regulate the actuator to adjust a timing of the engine valve based on the characteristic of the fuel.

  16. Automatic analysis of the control of metabolic networks.

    PubMed

    Bayram, M

    1996-09-01

    In this paper we apply computer algebra techniques to analyze the control of metabolic networks. For this purpose, a computer program based on metabolic control theory was developed. When a stoichiometry matrix of the metabolic networks is given, the program calculates all the control coefficients (flux and metabolic control coefficients, summation and connectivity relationships) using elasticity coefficients. The program can be applied to any metabolic network which includes unlimited steps and intermediate metabolites. PMID:8889337

  17. Analysis and control of cavity flow

    NASA Astrophysics Data System (ADS)

    Kourta, A.; Vitale, E.

    2008-07-01

    A flow above a cavity leads to an unsteady separated flow. This configuration exhibits an intense aeroacoustic coupling, where very intense aerodynamic noise can be emitted. Moreover, a majority of tangential flow above a cavity has an oscillatory character, resulting from a strong coupling between the acoustic and the flow dynamics. In the present work, we are interested in characterizing the dynamics and the frequency distribution of a cavity flow. First, the dynamics of the cavity are analyzed and the frequency distribution is established, which is followed by a study of nonlinear interaction. An open loop control using a synthetic jet is then applied in order to reduce noise generation. Finally, by choosing suitable jet parameters a significant noise reduction is obtained.

  18. Fuzzy Current-Mode Control and Stability Analysis

    NASA Technical Reports Server (NTRS)

    Kopasakis, George

    2000-01-01

    In this paper a current-mode control (CMC) methodology is developed for a buck converter by using a fuzzy logic controller. Conventional CMC methodologies are based on lead-lag compensation with voltage and inductor current feedback. In this paper the converter lead-lag compensation will be substituted with a fuzzy controller. A small-signal model of the fuzzy controller will also be developed in order to examine the stability properties of this buck converter control system. The paper develops an analytical approach, introducing fuzzy control into the area of CMC.

  19. Glycerin-Based Hydrogel for Infection Control

    PubMed Central

    Stout, Edward I.; McKessor, Angie

    2012-01-01

    Problem Infection is a major problem in the health and wellbeing of patients in hospitals, nursing homes, and other medical facilities as well as the homecare patients and the general public. According to Scientia Advisors, wound care costs the healthcare system over $7 billion in 2009. After adding the cost associated with potential complications such as infections, extended physician care, and lengthy hospital stays, the annual wound care expenditures well exceeded over $20 billion.1 There are 20 million reported cases of diabetes per year and more every day. Because of the fact that leg ulcers are the number one health problem of men coupled with the rise in drug resistance of infections, the importance of providing the professional and the public with relatively simple and affordable wound care is of extreme importance. Often the wounds can become chronic wounds, which then result in long-term nursing expense in time and supplies or, worse yet, can result in expensive amputations ranging from $5000 to $40,000 per patient. Solution There are many dressing options now available for treating wounds with components such as glycerin, honey, salt, and many other natural products, with some dressings being more appropriate than others. In 1988, a patented glycerin-based dressing was introduced to the market, called Elasto-Gel™.2 New Technology Elasto-Gel™ is a glycerin-based gel sheet (65%) combined with a hydrophilic polymer that causes the sheet to absorb the exudate from the wound and simultaneously release the glycerin from the gel, which adds many benefits to the wound for excellent healing outcomes. The gel sheet is 1/8th of an inch thick with a four-way stretch backing. It has the ability to absorb 3–4 times its own weight of fluids. The dressing will not dry out or allow the exudate to dry out, thus keeping the dressing from becoming bonded to the wound or the surrounding tissue. It does not have adhesive properties and, therefore, will not cause damage

  20. Context-Based E-Health System Access Control Mechanism

    NASA Astrophysics Data System (ADS)

    Al-Neyadi, Fahed; Abawajy, Jemal H.

    E-Health systems logically demand a sufficiently fine-grained authorization policy for access control. The access to medical information should not be just role-based but should also include the contextual condition of the role to access data. In this paper, we present a mechanism to extend the standard role-based access control to incorporate contextual information for making access control decisions in e-health application. We present an architecture consisting of authorisation and context infrastructure that work cooperatively to grant access rights based on context-aware authorization policies and context information.

  1. Robust identification of backbone curves using control-based continuation

    NASA Astrophysics Data System (ADS)

    Renson, L.; Gonzalez-Buelga, A.; Barton, D. A. W.; Neild, S. A.

    2016-04-01

    Control-based continuation is a recently developed approach for testing nonlinear dynamic systems in a controlled manner and exploring their dynamic features as system parameters are varied. In this paper, control-based continuation is adapted to follow the locus where system response and excitation are in quadrature, extracting the backbone curve of the underlying conservative system. The method is applied to a single-degree-of-freedom oscillator under base excitation, and the results are compared with the standard resonant-decay method.

  2. Abstracting event-based control models for high autonomy systems

    NASA Technical Reports Server (NTRS)

    Luh, Cheng-Jye; Zeigler, Bernard P.

    1993-01-01

    A high autonomy system needs many models on which to base control, management, design, and other interventions. These models differ in level of abstraction and in formalism. Concepts and tools are needed to organize the models into a coherent whole. The paper deals with the abstraction processes for systematic derivation of related models for use in event-based control. The multifaceted modeling methodology is briefly reviewed. The morphism concepts needed for application to model abstraction are described. A theory for supporting the construction of DEVS models needed for event-based control is then presented. An implemented morphism on the basis of this theory is also described.

  3. Extremum seeking-based adaptive control for electromagnetic actuators

    NASA Astrophysics Data System (ADS)

    Benosman, Mouhacine; Atınç, Gökhan M.

    2015-03-01

    In this paper, we present a learning-based adaptive method to solve the problem of robust trajectory tracking for electromagnetic actuators. We merge a nonlinear backstepping controller that ensures bounded input/bounded states stability, with a multi-variable extremum seeking model-free learning algorithm. The learning algorithm is used to estimate online the uncertain parameters of the model, in this sense, we propose a learning-based adaptive controller. We present a proof of stability of this learning-based nonlinear controller when considering uncertainties with linear parametrisation. The efficiency of this approach is shown on a numerical example.

  4. Structural controllability of complex networks based on preferential matching.

    PubMed

    Zhang, Xizhe; Lv, Tianyang; Yang, XueYing; Zhang, Bin

    2014-01-01

    Minimum driver node sets (MDSs) play an important role in studying the structural controllability of complex networks. Recent research has shown that MDSs tend to avoid high-degree nodes. However, this observation is based on the analysis of a small number of MDSs, because enumerating all of the MDSs of a network is a #P problem. Therefore, past research has not been sufficient to arrive at a convincing conclusion. In this paper, first, we propose a preferential matching algorithm to find MDSs that have a specific degree property. Then, we show that the MDSs obtained by preferential matching can be composed of high- and medium-degree nodes. Moreover, the experimental results also show that the average degree of the MDSs of some networks tends to be greater than that of the overall network, even when the MDSs are obtained using previous research method. Further analysis shows that whether the driver nodes tend to be high-degree nodes or not is closely related to the edge direction of the network. PMID:25375628

  5. Structural Controllability of Complex Networks Based on Preferential Matching

    PubMed Central

    Zhang, Xizhe; Lv, Tianyang; Yang, XueYing; Zhang, Bin

    2014-01-01

    Minimum driver node sets (MDSs) play an important role in studying the structural controllability of complex networks. Recent research has shown that MDSs tend to avoid high-degree nodes. However, this observation is based on the analysis of a small number of MDSs, because enumerating all of the MDSs of a network is a #P problem. Therefore, past research has not been sufficient to arrive at a convincing conclusion. In this paper, first, we propose a preferential matching algorithm to find MDSs that have a specific degree property. Then, we show that the MDSs obtained by preferential matching can be composed of high- and medium-degree nodes. Moreover, the experimental results also show that the average degree of the MDSs of some networks tends to be greater than that of the overall network, even when the MDSs are obtained using previous research method. Further analysis shows that whether the driver nodes tend to be high-degree nodes or not is closely related to the edge direction of the network. PMID:25375628

  6. Wavelet-based image analysis system for soil texture analysis

    NASA Astrophysics Data System (ADS)

    Sun, Yun; Long, Zhiling; Jang, Ping-Rey; Plodinec, M. John

    2003-05-01

    Soil texture is defined as the relative proportion of clay, silt and sand found in a given soil sample. It is an important physical property of soil that affects such phenomena as plant growth and agricultural fertility. Traditional methods used to determine soil texture are either time consuming (hydrometer), or subjective and experience-demanding (field tactile evaluation). Considering that textural patterns observed at soil surfaces are uniquely associated with soil textures, we propose an innovative approach to soil texture analysis, in which wavelet frames-based features representing texture contents of soil images are extracted and categorized by applying a maximum likelihood criterion. The soil texture analysis system has been tested successfully with an accuracy of 91% in classifying soil samples into one of three general categories of soil textures. In comparison with the common methods, this wavelet-based image analysis approach is convenient, efficient, fast, and objective.

  7. Advanced stability analysis for laminar flow control

    NASA Technical Reports Server (NTRS)

    Orszag, S. A.

    1981-01-01

    Five classes of problems are addressed: (1) the extension of the SALLY stability analysis code to the full eighth order compressible stability equations for three dimensional boundary layer; (2) a comparison of methods for prediction of transition using SALLY for incompressible flows; (3) a study of instability and transition in rotating disk flows in which the effects of Coriolis forces and streamline curvature are included; (4) a new linear three dimensional instability mechanism that predicts Reynolds numbers for transition to turbulence in planar shear flows in good agreement with experiment; and (5) a study of the stability of finite amplitude disturbances in axisymmetric pipe flow showing the stability of this flow to all nonlinear axisymmetric disturbances.

  8. Flame spectral analysis for boiler control

    SciTech Connect

    Metcalfe, C.I.; Cole, W.E.; Batra, S.K.

    1987-09-01

    An instrument has been developed by Tecogen, Inc., to determine the combustion characteristics of individual burners in multiburner installations. The technology is based on measuring the emissions in the ultraviolet (uv) and infrared (ir) spectral range from the flames and using these measurements to determine the burner operating conditions. Two prototype instruments have been installed on package boilers at a Con Edison powerplant and a Polaroid facility, and their performance has been evaluated. These instruments provide data relating to the variations in the ir and uv spectrum with a change in the combustion condition in individual burners. This paper describes the instrument's operation and these tests. 2 refs.

  9. Disturbance Rejection Based Test Rocket Control System Design and Validation

    NASA Astrophysics Data System (ADS)

    Yang, H.; Zhang, S.; Li, T.; Zhang, Y.

    2015-09-01

    This paper presents a novel design and validation for the three-channel attitude controller of a STT test rocket based on the extended state observer approach. The uniform second order integral-chain state space model is firstly established for the control variable of the angle of attack, angle of sideslip and roll angle. Combined with the pole placement, the extended state observer is applied to the disturbance rejection design of the attitude controller. Through numerical and hardware-in-the-loop simulation with uncertainties considered, the effectiveness and robustness of the controller are illustrated and verified. Finally, the performance of the controller is validated by flight-test with satisfactory results.

  10. Structural analysis and design of multivariable control systems: An algebraic approach

    NASA Technical Reports Server (NTRS)

    Tsay, Yih Tsong; Shieh, Leang-San; Barnett, Stephen

    1988-01-01

    The application of algebraic system theory to the design of controllers for multivariable (MV) systems is explored analytically using an approach based on state-space representations and matrix-fraction descriptions. Chapters are devoted to characteristic lambda matrices and canonical descriptions of MIMO systems; spectral analysis, divisors, and spectral factors of nonsingular lambda matrices; feedback control of MV systems; and structural decomposition theories and their application to MV control systems.

  11. Progress towards SAR based ecosystem analysis

    NASA Technical Reports Server (NTRS)

    Ranson, K. Jon; Sun, Guoqing

    1991-01-01

    Recent progress towards a synthetic aperture radar (SAR) based system for determining forest ecosystem attributes is discussed. Our SAR data processing and analysis sequence, from calibration through classification, is described. In addition, the usefulness of SAR image data for identifying ecosystem classes is discussed.

  12. Emotional Learning Based Intelligent Controllers for Rotor Flux Oriented Control of Induction Motor

    NASA Astrophysics Data System (ADS)

    Abdollahi, Rohollah; Farhangi, Reza; Yarahmadi, Ali

    2014-08-01

    This paper presents design and evaluation of a novel approach based on emotional learning to improve the speed control system of rotor flux oriented control of induction motor. The controller includes a neuro-fuzzy system with speed error and its derivative as inputs. A fuzzy critic evaluates the present situation, and provides the emotional signal (stress). The controller modifies its characteristics so that the critics stress is reduced. The comparative simulation results show that the proposed controller is more robust and hence found to be a suitable replacement of the conventional PI controller for the high performance industrial drive applications.

  13. Energy-saving technology of vector controlled induction motor based on the adaptive neuro-controller

    NASA Astrophysics Data System (ADS)

    Engel, E.; Kovalev, I. V.; Karandeev, D.

    2015-10-01

    The ongoing evolution of the power system towards a Smart Grid implies an important role of intelligent technologies, but poses strict requirements on their control schemes to preserve stability and controllability. This paper presents the adaptive neuro-controller for the vector control of induction motor within Smart Gird. The validity and effectiveness of the proposed energy-saving technology of vector controlled induction motor based on adaptive neuro-controller are verified by simulation results at different operating conditions over a wide speed range of induction motor.

  14. Aircraft Accident Prevention: Loss-of-Control Analysis

    NASA Technical Reports Server (NTRS)

    Kwatny, Harry G.; Dongmo, Jean-Etienne T.; Chang, Bor-Chin; Bajpai, Guarav; Yasar, Murat; Belcastro, Christine M.

    2009-01-01

    The majority of fatal aircraft accidents are associated with loss-of-control . Yet the notion of loss-of-control is not well-defined in terms suitable for rigorous control systems analysis. Loss-of-control is generally associated with flight outside of the normal flight envelope, with nonlinear influences, and with an inability of the pilot to control the aircraft. The two primary sources of nonlinearity are the intrinsic nonlinear dynamics of the aircraft and the state and control constraints within which the aircraft must operate. In this paper we examine how these nonlinearities affect the ability to control the aircraft and how they may contribute to loss-of-control. Examples are provided using NASA s Generic Transport Model.

  15. A system framework of inter-enterprise machining quality control based on fractal theory

    NASA Astrophysics Data System (ADS)

    Zhao, Liping; Qin, Yongtao; Yao, Yiyong; Yan, Peng

    2014-03-01

    In order to meet the quality control requirement of dynamic and complicated product machining processes among enterprises, a system framework of inter-enterprise machining quality control based on fractal was proposed. In this system framework, the fractal-specific characteristic of inter-enterprise machining quality control function was analysed, and the model of inter-enterprise machining quality control was constructed by the nature of fractal structures. Furthermore, the goal-driven strategy of inter-enterprise quality control and the dynamic organisation strategy of inter-enterprise quality improvement were constructed by the characteristic analysis on this model. In addition, the architecture of inter-enterprise machining quality control based on fractal was established by means of Web service. Finally, a case study for application was presented. The result showed that the proposed method was available, and could provide guidance for quality control and support for product reliability in inter-enterprise machining processes.

  16. Design of a nonlinear backstepping control strategy of grid interconnected wind power system based PMSG

    NASA Astrophysics Data System (ADS)

    Errami, Y.; Obbadi, A.; Sahnoun, S.; Benhmida, M.; Ouassaid, M.; Maaroufi, M.

    2016-07-01

    This paper presents nonlinear backstepping control for Wind Power Generation System (WPGS) based Permanent Magnet Synchronous Generator (PMSG) and connected to utility grid. The block diagram of the WPGS with PMSG and the grid side back-to-back converter is established with the dq frame of axes. This control scheme emphasises the regulation of the dc-link voltage and the control of the power factor at changing wind speed. Besides, in the proposed control strategy of WPGS, Maximum Power Point Tracking (MPPT) technique and pitch control are provided. The stability of the regulators is assured by employing Lyapunov analysis. The proposed control strategy for the system has been validated by MATLAB simulations under varying wind velocity and the grid fault condition. In addition, a comparison of simulation results based on the proposed Backstepping strategy and conventional Vector Control is provided.

  17. A reinforcement learning-based architecture for fuzzy logic control

    NASA Technical Reports Server (NTRS)

    Berenji, Hamid R.

    1992-01-01

    This paper introduces a new method for learning to refine a rule-based fuzzy logic controller. A reinforcement learning technique is used in conjunction with a multilayer neural network model of a fuzzy controller. The approximate reasoning based intelligent control (ARIC) architecture proposed here learns by updating its prediction of the physical system's behavior and fine tunes a control knowledge base. Its theory is related to Sutton's temporal difference (TD) method. Because ARIC has the advantage of using the control knowledge of an experienced operator and fine tuning it through the process of learning, it learns faster than systems that train networks from scratch. The approach is applied to a cart-pole balancing system.

  18. Modeling mandatory access control in role-based security systems

    SciTech Connect

    Nyanchama, M.; Osborn, S.

    1996-12-31

    This paper discusses the realization of mandatory access control in role-based protection systems. Starting from the basic definitions of roles, their application in security and the basics of the concept of mandatory access control, we develop a scheme of role-based protection that realizes mandatory access control. The basis of this formulation develops from the recognition that roles can be seen as facilitating access to some given information context. By handling each of the role contexts as independent security levels of information, we simulate mandatory access by imposing the requirements of mandatory access control. Among the key considerations, we propose a means of taming Trojan horses by imposing acyclic information flow among contexts in role-based protection systems. The acyclic information flows and suitable access rules incorporate secrecy which is an essential component of mandatory access control.

  19. Cognitive Task Analysis of Prioritization in Air Traffic Control.

    ERIC Educational Resources Information Center

    Redding, Richard E.; And Others

    A cognitive task analysis was performed to analyze the key cognitive components of the en route air traffic controllers' jobs. The goals were to ascertain expert mental models and decision-making strategies and to identify important differences in controller knowledge, skills, and mental models as a function of expertise. Four groups of…

  20. Manual-control Analysis Applied to the Money-supply Control Task

    NASA Technical Reports Server (NTRS)

    Wingrove, R. C.

    1984-01-01

    The recent procedure implemented by the Federal Reserve Board to control the money supply is formulated in the form of a tracking model as used in the study of manual-control tasks. Using this model, an analysis is made to determine the effect of monetary control on the fluctuations in economic output. The results indicate that monetary control can reduce the amplitude of fluctuations at frequencies near the region of historic business cycles. However, with significant time lags in the control loop, monetary control tends to increase the amplitude of the fluctuations at the higher frequencies. How the investigator or student can use the tools developed in the field of manual-control analysis to study the nature of economic fluctuations and to examine different strategies for stabilization is examined.

  1. VIEW TO WEST FROM AIRFIELD APRON, SHOWING BASE OPERATIONS CONTROL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW TO WEST FROM AIRFIELD APRON, SHOWING BASE OPERATIONS CONTROL TOWER (FACILITY NO. 365), AND RESERVOIR HILL BEYOND Hangar NO. 9, AT RIGHT - Hamilton Field, East of Nave Drive, Novato, Marin County, CA

  2. A Design and Control Environment for Internet-Based Telerobotics

    NASA Technical Reports Server (NTRS)

    Oboe, Roberto; Fiorini, Paolo

    1997-01-01

    This paper describes an environment for the design, simulation and control of Internet-based force-relflecting telerobotc systems. We define these systems as using a segment of the computer network to connect the master to the slave.

  3. Ethernet Based Embedded IOC for FEL Control Systems

    SciTech Connect

    Yan, Jianxun; Sexton, Daniel; Grippo, Albert; Moore, Steven; Jordan, Kevin

    2008-01-01

    An Ethernet based embedded Input Output Controller (IOC) has been developed as part of an upgrade to the control system for the Free Electron Laser Project at Jefferson Lab. Currently most of the FEL systems are controlled, configured and monitored using a central VME bus-based configuration. These crate based systems are limited in growth and usually interleave multiple systems. In order to accommodate incremental system growth and lower channel costs, we developed a stand-alone system, an Ethernet based embedded controller called the Single Board IOC (SBIOC). The SBIOC is a module which integrates an Altera FPGA and the Arcturus uCdimm Coldfire 5282 Microcontroller daughter card into one module, which can be easily configured for different kinds of I/O devices. The microcontroller is a complete System-on-Module, including three highly integrated functional blocks, the core processor, memory, and Ethernet communication. A real-time operating system, RTEMS is cross compiled with

  4. Multiple channel coincidence detector and controller for microseismic data analysis

    DOEpatents

    Fasching, George E.

    1976-11-16

    A multiple channel coincidence detector circuit is provided for analyzing data either in real time or recorded data on a magnetic tape during an experiment for determining location and progression of fractures in an oil field or the like while water is being injected at high pressure in wells located in the field. The circuit is based upon the utilization of a set of parity generator trees combined with monostable multivibrators to detect the occurrence of two events at any pair of channel input terminals that are within a preselected time frame and have an amplitude above a preselected magnitude. The parity generators perform an exclusive OR function in a timing circuit composed of monostable multivibrators that serve to yield an output when two events are present in the preselected time frame. Any coincidences falling outside this time frame are considered either noise or not otherwise useful in the analysis of the recorded data. Input pulses of absolute magnitude below the low-level threshold setting of a bipolar low-level threshold detector are unwanted and therefore rejected. A control output is provided for a utilization device from a coincidence hold circuit that may be used to halt a tape search unit at the time of coincidence or perform other useful control functions.

  5. Smart microneedle coatings for controlled delivery and biomedical analysis.

    PubMed

    Khan, H; Mehta, P; Msallam, H; Armitage, D; Ahmad, Z

    2014-11-01

    The work presented demonstrates an unconventional approach in the preparation of smart microneedle (MN) coatings utilising electrohydrodynamic atomisation (EHDA) principles. Stainless steel (600-900 µm in height) MNs were coupled to a ground electrode (in the EHDA coating set-up) with the deposition distance and collecting methodology varied for an ethanol:methanol (50:50) vehicle system. The preparation of nano- and micrometre-scaled pharmaceutical coatings was achieved. Fluorescein dye (serving as potential drug, sensory materials or disease state markers) and polyvinylpyrrolidone (PVP, polymer matrix system) formed the remaining components of the coating formulation. Based on these excipients and by varying the coating process, particles (100 nm to 3 µm) and fibres (400 nm to 1 µm) were deposited directly on MNs in controlled and selectable fashion (flow rates variable ∼ 5-50 µL/min, applied voltage variable 6-19 kV). These demonstrated options for multiple targeting and analysis applications. The underlying EHDA process permits room temperature fabrication, controlled output and scale-up potential for emerging MN devices as drug systems or lab-chip testing devices. PMID:24892742

  6. Fault tolerant control based on interval type-2 fuzzy sliding mode controller for coaxial trirotor aircraft.

    PubMed

    Zeghlache, Samir; Kara, Kamel; Saigaa, Djamel

    2015-11-01

    In this paper, a robust controller for a Six Degrees of Freedom (6 DOF) coaxial trirotor helicopter control is proposed in presence of defects in the system. A control strategy based on the coupling of the interval type-2 fuzzy logic control and sliding mode control technique are used to design a controller. The main purpose of this work is to eliminate the chattering phenomenon and guaranteeing the stability and the robustness of the system. In order to achieve this goal, interval type-2 fuzzy logic control has been used to generate the discontinuous control signal. The simulation results have shown that the proposed control strategy can greatly alleviate the chattering effect, and perform good reference tracking in presence of defects in the system. PMID:26428878

  7. EPROM-based LSI-11 for distributed instrumentation control

    SciTech Connect

    Hunt, D.N.

    1981-11-11

    The LLNL Nuclear Chemistry Counting Facility (NCCF) is being converted to a modern production facility. A computer network has been designed and built to implement this conversion. The outermost node of the computer network is a dedicated EPROM-based controller. The controller handles the details of driving the attached nuclear instrumentation, providing a standard interface to the remainder of the network. This paper addresses the design and the implementation of the dedicated instrumentation controller.

  8. Observer-based controller design for networked control systems with sensor quantisation and random communication delay

    NASA Astrophysics Data System (ADS)

    Liu, Ming; You, Jia

    2012-10-01

    This article addresses the study of observer-based controller design for network-based control systems in the presence of output quantisation and random communication delay simultaneously. In the communication channel, the output measurement are quantised before transmission, and two kinds of network-induced delays are taken into account simultaneously: (i) random delay from sensor to controller and (ii) random delay from controller to actuator. These two types of random delays are modelled as two independent Bernoulli distributed white sequences. The observer-based controller is synthesised to stabilise the networked closed-loop system in the sense of stochastic stability. Sufficient conditions for the existence of the controller are provided by stochastic Lyapunov method. An illustrative numerical example is employed to demonstrate the applicability and flexibility of the proposed design strategy.

  9. A PC-Based Controller for Dextrous Arms

    NASA Technical Reports Server (NTRS)

    Fiorini, Paolo; Seraji, Homayoun; Long, Mark

    1996-01-01

    This paper describes the architecture and performance of a PC-based controller for 7-DOF dextrous manipulators. The computing platform is a 486-based personal computer equipped with a bus extender to access the robot Multibus controller, together with a single board computer as the graphical engine, and with a parallel I/O board to interface with a force-torque sensor mounted on the manipulator wrist.

  10. Biotechnology-based odour control: design criteria and performance data.

    PubMed

    Quigley, C; Easter, C; Burrowes, P; Witherspoon, J

    2004-01-01

    As neighbouring areas continue to encroach upon wastewater treatment plants, there is an increasing need for odour control to mitigate potential negative offsite odorous impacts. One technology that is gaining widespread acceptance is biotechnology, which utilises the inherent ability of certain microorganisms to biodegrade offensive odorous compounds. Two main advantages of this form of treatment over other odour control technologies include the absence of hazardous chemicals and relatively low operation and maintenance requirements. The purpose of this paper is to provide information related to odour control design criteria used in sizing/selecting biotechnology-based odour control technologies, and to provide odour removal performance data obtained from several different biotechnology-based odour control systems. CH2M HILL has collected biotechnology-based odour control performance data over the last several years in order to track the continued performance of various biofilters and biotowers over time. Specifically, odour removal performance data have been collected from soil-, organic- and inorganic-media biofilters and inert inorganic media biotowers. Results indicate that biotechnology-based odour control is a viable and consistent technology capable of achieving high removal performance for odour and hydrogen sulphide. It is anticipated that the information presented in this paper will be of interest to anyone involved with odour control technology evaluation/selection or design review. PMID:15484776

  11. Connected Dominating Set Based Topology Control in Wireless Sensor Networks

    ERIC Educational Resources Information Center

    He, Jing

    2012-01-01

    Wireless Sensor Networks (WSNs) are now widely used for monitoring and controlling of systems where human intervention is not desirable or possible. Connected Dominating Sets (CDSs) based topology control in WSNs is one kind of hierarchical method to ensure sufficient coverage while reducing redundant connections in a relatively crowded network.…

  12. Internet-Based Treatment for Insomnia: A Controlled Evaluation

    ERIC Educational Resources Information Center

    Strom, Lars; Pettersson, Richard; Andersson, Gerhard

    2004-01-01

    This study investigated the effects of an Internet-based intervention for insomnia. Participants who met criteria for insomnia (N = 109) were randomly assigned to either a cognitive-behavioral self-help treatment or a waiting list control condition. The 5-week intervention mainly consisted of sleep restriction, stimulus control, and cognitive…

  13. Robust observer-based adaptive fuzzy sliding mode controller

    NASA Astrophysics Data System (ADS)

    Oveisi, Atta; Nestorović, Tamara

    2016-08-01

    In this paper, a new observer-based adaptive fuzzy integral sliding mode controller is proposed based on the Lyapunov stability theorem. The plant is subjected to a square-integrable disturbance and is assumed to have mismatch uncertainties both in state- and input-matrices. Based on the classical sliding mode controller, the equivalent control effort is obtained to satisfy the sufficient requirement of sliding mode controller and then the control law is modified to guarantee the reachability of the system trajectory to the sliding manifold. In order to relax the norm-bounded constrains on the control law and solve the chattering problem of sliding mode controller, a fuzzy logic inference mechanism is combined with the controller. An adaptive law is then introduced to tune the parameters of the fuzzy system on-line. Finally, for evaluating the controller and the robust performance of the closed-loop system, the proposed regulator is implemented on a real-time mechanical vibrating system.

  14. Active control of vibration using a fuzzy control method based on scaling universes of discourse

    NASA Astrophysics Data System (ADS)

    Si, Hongwei; Li, Dongxu

    2007-06-01

    Large flexible space structures are complex in structural dynamic characteristics. The control method based on custom control theory and modern control theory is difficult to solve for the complex problem. The fuzzy controller is not dependent on the accurate model. But the precision of a conventional fuzzy controller is not good, and the adaptive ability of a conventional fuzzy controller is limited. The fuzzy controller can make the system surge. Scaling universes of discourse is an effective method to improve the performance of the fuzzy controller. This paper is aimed at the difficult problem of designing a stable adaptive controller based on scaling universes of discourse, and letting input membership function and output membership function be denoted as input universes of discourse and the center value of output membership function, respectively. A kind of Lyapunov function, designed as an adaptive law of input universes of discourse and the center value of output membership function, was then adopted. A kind of stable self-adaptive fuzzy controller based on scaling universes of discourse is designed in this paper for the vibration control of a large flexible space truss driven by piezoelectric sensors and actuators (PZTs).

  15. Ontology-Based Analysis of Microarray Data.

    PubMed

    Giuseppe, Agapito; Milano, Marianna

    2016-01-01

    The importance of semantic-based methods and algorithms for the analysis and management of biological data is growing for two main reasons. From a biological side, knowledge contained in ontologies is more and more accurate and complete, from a computational side, recent algorithms are using in a valuable way such knowledge. Here we focus on semantic-based management and analysis of protein interaction networks referring to all the approaches of analysis of protein-protein interaction data that uses knowledge encoded into biological ontologies. Semantic approaches for studying high-throughput data have been largely used in the past to mine genomic and expression data. Recently, the emergence of network approaches for investigating molecular machineries has stimulated in a parallel way the introduction of semantic-based techniques for analysis and management of network data. The application of these computational approaches to the study of microarray data can broad the application scenario of them and simultaneously can help the understanding of disease development and progress. PMID:25971913

  16. Spatially-based quality control for daily precipitation datasets

    NASA Astrophysics Data System (ADS)

    Serrano-Notivoli, Roberto; de Luis, Martín; Beguería, Santiago; Ángel Saz, Miguel

    2016-04-01

    There are many reasons why wrong data can appear in original precipitation datasets but their common characteristic is that all of them do not correspond to the natural variability of the climate variable. For this reason, is necessary a comprehensive analysis of the data of each station in each day, to be certain that the final dataset will be consistent and reliable. Most of quality control techniques applied over daily precipitation are based on the comparison of each observed value with the rest of values in same series or in reference series built from its nearest stations. These methods are inherited from monthly precipitation studies, but in daily scale the variability is bigger and the methods have to be different. A common character shared by all of these approaches is that they made reconstructions based on the best-correlated reference series, which could be a biased decision because, for example, a extreme precipitation occurred in one day in more than one station could be flagged as erroneous. We propose a method based on the specific conditions of the day and location to determine the reliability of each observation. This method keeps the local variance of the variable and the time-structure independence. To do that, individually for each daily value, we first compute the probability of precipitation occurrence through a multivariate logistic regression using the 10 nearest observations in a binomial mode (0=dry; 1=wet), this produces a binomial prediction (PB) between 0 and 1. Then, we compute a prediction of precipitation magnitude (PM) with the raw data of the same 10 nearest observations. Through these predictions we explore the original data in each day and location by five criteria: 1) Suspect data; 2) Suspect zero; 3) Suspect outlier; 4) Suspect wet and 5) Suspect dry. Tests over different datasets addressed that flagged data depend mainly on the number of available data and the homogeneous distribution of them.

  17. Control of Space-Based Electron Beam Free Form Fabrication

    NASA Technical Reports Server (NTRS)

    Seifzer. W. J.; Taminger, K. M.

    2007-01-01

    Engineering a closed-loop control system for an electron beam welder for space-based additive manufacturing is challenging. For earth and space based applications, components must work in a vacuum and optical components become occluded with metal vapor deposition. For extraterrestrial applications added components increase launch weight, increase complexity, and increase space flight certification efforts. Here we present a software tool that closely couples path planning and E-beam parameter controls into the build process to increase flexibility. In an environment where data collection hinders real-time control, another approach is considered that will still yield a high quality build.

  18. Electroencephalography (EEG) Based Control in Assistive Mobile Robots: A Review

    NASA Astrophysics Data System (ADS)

    Krishnan, N. Murali; Mariappan, Muralindran; Muthukaruppan, Karthigayan; Hijazi, Mohd Hanafi Ahmad; Kitt, Wong Wei

    2016-03-01

    Recently, EEG based control in assistive robot usage has been gradually increasing in the area of biomedical field for giving quality and stress free life for disabled and elderly people. This study reviews the deployment of EGG based control in assistive robots, especially for those who in need and neurologically disabled. The main objective of this paper is to describe the methods used for (i) EEG data acquisition and signal preprocessing, (ii) feature extraction and (iii) signal classification methods. Besides that, this study presents the specific research challenges in the designing of these control systems and future research directions.

  19. System safety analysis of well-control equipment

    SciTech Connect

    Fowler, J.H.; Roche, J.R.

    1994-09-01

    In the wake of recent disasters in the oil and gas E and P and petrochemical industries, the importance of system safety analysis is becoming recognized. Reliability assessment techniques, which were developed in the nuclear-power-generation and defense industries, are potentially valuable tools for engineers in the offshore oil and gas business. BOP's and their control systems used on offshore rigs are typically made up of several subsystems. Hydraulic, pneumatic, and electronic modules are interfaced to provide functional control and monitoring of the mechanical BOP's and valves. Two techniques are used for reliability analysis of a blowout preventer (BOP) and a hydraulic control system. Failure modes and effects analysis (FMEA) examines each part and the consequences of its malfunction. Fault tree analysis (FTA) traces undesired events to their causes. Reliability calculations and data sources are addressed.

  20. DSP based lunar sampling control system for the coiling-type sampler

    NASA Astrophysics Data System (ADS)

    Ling, Yun; Song, Aiguo; Lu, Wei

    2011-12-01

    The paper develops a control system based on DSP28334 for lunar sampling, and provides the main structure of it. The critical hardware and software design of the system are introduced in detail. The emphasis is placed on the design and realization of the vibration control of the coiling-type sampler in the process of lunar sampling. A control strategy which combines manual-control and local autonomous control is applied for the lunar sampling control. And the sampling mechanism being controlled can realizes multi-motor units working at time-sharing, which reduces the power comsumption and increases the stability of the sampling system greatly. The practical application of the control strategy used for the coiling-type sampler is verified by the finite element analysis. The experiments results show that the system works with low power consumption and high efficiency, and the proposed strategy enables greater depth and better efficiency during sampling.

  1. WELDSMART: A vision-based expert system for quality control

    NASA Astrophysics Data System (ADS)

    Andersen, Kristinn; Barnett, Robert Joel; Springfield, James F.; Cook, George E.

    1992-09-01

    This work was aimed at exploring means for utilizing computer technology in quality inspection and evaluation. Inspection of metallic welds was selected as the main application for this development and primary emphasis was placed on visual inspection, as opposed to other inspection methods, such as radiographic techniques. Emphasis was placed on methodologies with the potential for use in real-time quality control systems. Because quality evaluation is somewhat subjective, despite various efforts to classify discontinuities and standardize inspection methods, the task of using a computer for both inspection and evaluation was not trivial. The work started out with a review of the various inspection techniques that are used for quality control in welding. Among other observations from this review was the finding that most weld defects result in abnormalities that may be seen by visual inspection. This supports the approach of emphasizing visual inspection for this work. Quality control consists of two phases: (1) identification of weld discontinuities (some of which may be severe enough to be classified as defects), and (2) assessment or evaluation of the weld based on the observed discontinuities. Usually the latter phase results in a pass/fail judgement for the inspected piece. It is the conclusion of this work that the first of the above tasks, identification of discontinuities, is the most challenging one. It calls for sophisticated image processing and image analysis techniques, and frequently ad hoc methods have to be developed to identify specific features in the weld image. The difficulty of this task is generally not due to limited computing power. In most cases it was found that a modest personal computer or workstation could carry out most computations in a reasonably short time period. Rather, the algorithms and methods necessary for identifying weld discontinuities were in some cases limited. The fact that specific techniques were finally developed and

  2. WELDSMART: A vision-based expert system for quality control

    NASA Technical Reports Server (NTRS)

    Andersen, Kristinn; Barnett, Robert Joel; Springfield, James F.; Cook, George E.

    1992-01-01

    This work was aimed at exploring means for utilizing computer technology in quality inspection and evaluation. Inspection of metallic welds was selected as the main application for this development and primary emphasis was placed on visual inspection, as opposed to other inspection methods, such as radiographic techniques. Emphasis was placed on methodologies with the potential for use in real-time quality control systems. Because quality evaluation is somewhat subjective, despite various efforts to classify discontinuities and standardize inspection methods, the task of using a computer for both inspection and evaluation was not trivial. The work started out with a review of the various inspection techniques that are used for quality control in welding. Among other observations from this review was the finding that most weld defects result in abnormalities that may be seen by visual inspection. This supports the approach of emphasizing visual inspection for this work. Quality control consists of two phases: (1) identification of weld discontinuities (some of which may be severe enough to be classified as defects), and (2) assessment or evaluation of the weld based on the observed discontinuities. Usually the latter phase results in a pass/fail judgement for the inspected piece. It is the conclusion of this work that the first of the above tasks, identification of discontinuities, is the most challenging one. It calls for sophisticated image processing and image analysis techniques, and frequently ad hoc methods have to be developed to identify specific features in the weld image. The difficulty of this task is generally not due to limited computing power. In most cases it was found that a modest personal computer or workstation could carry out most computations in a reasonably short time period. Rather, the algorithms and methods necessary for identifying weld discontinuities were in some cases limited. The fact that specific techniques were finally developed and

  3. Cognitive control predicts use of model-based reinforcement learning.

    PubMed

    Otto, A Ross; Skatova, Anya; Madlon-Kay, Seth; Daw, Nathaniel D

    2015-02-01

    Accounts of decision-making and its neural substrates have long posited the operation of separate, competing valuation systems in the control of choice behavior. Recent theoretical and experimental work suggest that this classic distinction between behaviorally and neurally dissociable systems for habitual and goal-directed (or more generally, automatic and controlled) choice may arise from two computational strategies for reinforcement learning (RL), called model-free and model-based RL, but the cognitive or computational processes by which one system may dominate over the other in the control of behavior is a matter of ongoing investigation. To elucidate this question, we leverage the theoretical framework of cognitive control, demonstrating that individual differences in utilization of goal-related contextual information--in the service of overcoming habitual, stimulus-driven responses--in established cognitive control paradigms predict model-based behavior in a separate, sequential choice task. The behavioral correspondence between cognitive control and model-based RL compellingly suggests that a common set of processes may underpin the two behaviors. In particular, computational mechanisms originally proposed to underlie controlled behavior may be applicable to understanding the interactions between model-based and model-free choice behavior. PMID:25170791

  4. A Modelica-based Model Library for Building Energy and Control Systems

    SciTech Connect

    Wetter, Michael

    2009-04-07

    This paper describes an open-source library with component models for building energy and control systems that is based on Modelica, an equation-based objectoriented language that is well positioned to become the standard for modeling of dynamic systems in various industrial sectors. The library is currently developed to support computational science and engineering for innovative building energy and control systems. Early applications will include controls design and analysis, rapid prototyping to support innovation of new building systems and the use of models during operation for controls, fault detection and diagnostics. This paper discusses the motivation for selecting an equation-based object-oriented language. It presents the architecture of the library and explains how base models can be used to rapidly implement new models. To demonstrate the capability of analyzing novel energy and control systems, the paper closes with an example where we compare the dynamic performance of a conventional hydronic heating system with thermostatic radiator valves to an innovative heating system. In the new system, instead of a centralized circulation pump, each of the 18 radiators has a pump whose speed is controlled using a room temperature feedback loop, and the temperature of the boiler is controlled based on the speed of the radiator pump. All flows are computed by solving for the pressure distribution in the piping network, and the controls include continuous and discrete time controls.

  5. Tensor Product Model Transformation Based Adaptive Integral-Sliding Mode Controller: Equivalent Control Method

    PubMed Central

    Zhao, Guoliang; Li, Hongxing

    2013-01-01

    This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model. PMID:24453897

  6. Performance analysis of reactive congestion control for ATM networks

    NASA Astrophysics Data System (ADS)

    Kawahara, Kenji; Oie, Yuji; Murata, Masayuki; Miyahara, Hideo

    1995-05-01

    In ATM networks, preventive congestion control is widely recognized for efficiently avoiding congestion, and it is implemented by a conjunction of connection admission control and usage parameter control. However, congestion may still occur because of unpredictable statistical fluctuation of traffic sources even when preventive control is performed in the network. In this paper, we study another kind of congestion control, i.e., reactive congestion control, in which each source changes its cell emitting rate adaptively to the traffic load at the switching node (or at the multiplexer). Our intention is that, by incorporating such a congestion control method in ATM networks, more efficient congestion control is established. We develop an analytical model, and carry out an approximate analysis of reactive congestion control algorithm. Numerical results show that the reactive congestion control algorithms are very effective in avoiding congestion and in achieving the statistical gain. Furthermore, the binary congestion control algorithm with pushout mechanism is shown to provide the best performance among the reactive congestion control algorithms treated here.

  7. Using new aggregation operators in rule-based intelligent control

    NASA Technical Reports Server (NTRS)

    Berenji, Hamid R.; Chen, Yung-Yaw; Yager, Ronald R.

    1990-01-01

    A new aggregation operator is applied in the design of an approximate reasoning-based controller. The ordered weighted averaging (OWA) operator has the property of lying between the And function and the Or function used in previous fuzzy set reasoning systems. It is shown here that, by applying OWA operators, more generalized types of control rules, which may include linguistic quantifiers such as Many and Most, can be developed. The new aggregation operators, as tested in a cart-pole balancing control problem, illustrate improved performance when compared with existing fuzzy control aggregation schemes.

  8. The design of the elevator control based on PLC

    NASA Astrophysics Data System (ADS)

    Zheng, Yanling; Ning, Xin; Wang, Zhankui

    2011-10-01

    Elevator is the vertical vehicle of modern high building,which has close relationship with the life of people.The elevator developed very quickly with the increasing demand of people.The drag of elevator developed to use the frequency conversion and voltage transformation to realize the speed regulation.The logic control of elevator is accomplished by PLC instead of relay control.The article uses the PLC to control the elevator based on existed current frequency transformer.Through the resonable choice and design,we can increase the control level of the elevator,and improve the safety and comfortable feeling of elevator,and obtain perfect contrl effect.

  9. Expectation-Based Control of Noise and Chaos

    NASA Technical Reports Server (NTRS)

    Zak, Michael

    2006-01-01

    A proposed approach to control of noise and chaos in dynamic systems would supplement conventional methods. The approach is based on fictitious forces composed of expectations governed by Fokker-Planck or Liouville equations that describe the evolution of the probability densities of the controlled parameters. These forces would be utilized as feedback control forces that would suppress the undesired diffusion of the controlled parameters. Examples of dynamic systems in which the approach is expected to prove beneficial include spacecraft, electronic systems, and coupled lasers.

  10. Engine control system having fuel-based timing

    DOEpatents

    Willi, Martin L.; Fiveland, Scott B.; Montgomery, David T.; Gong, Weidong

    2012-04-03

    A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a sensor configured to generate a signal indicative of an amount of an air/fuel mixture remaining within the cylinder after completion of a first combustion event and a controller in communication with the actuator and the sensor. The controller may be configured to compare the amount with a desired amount, and to selectively regulate the actuator to adjust a timing of the engine valve associated with a subsequent combustion event based on the comparison.

  11. Effects of joint controller on analytical modal analysis of rotational flexible manipulator

    NASA Astrophysics Data System (ADS)

    Chu, Ming; Zhang, Yanheng; Chen, Gang; Sun, Hanxu

    2015-04-01

    Modal analysis is a fundamental and important task for modeling and control of the flexible manipulator. However, almost all of the traditional modal analysis methods view the flexible manipulator as a pure mechanical structure and neglect feedback action of joint controller. In order to study the effects of joint controller on the modal analysis of rotational flexible manipulator, a closed-loop analytical modal analysis method is proposed. Firstly, two exact boundary constraints, namely servo feedback constraint and bending moment constraint, are derived to solve the vibration partial differential equation. It is found that the stiffness and damping gains of joint controller are both included in the boundary conditions, which lead to an unconventional secular term. Secondly, analytical algorithm based on Ritz approach is developed by using Laplace transform and complex modal approach to obtain the natural frequencies and mode shapes. And then, the numerical simulations are performed and the computational results show that joint controller has pronounced influence on the modal parameters: joint controller stiffness reduces the natural frequency, while joint controller damping makes the shape phase non-zero. Furthermore, the validity of the presented conclusion is confirmed through experimental studies. These findings are expected to improve the performance of dynamics simulation systems and model-based controllers.

  12. Transaction-Based Controls for Building-Grid Integration: VOLTTRON™

    SciTech Connect

    Akyol, Bora A.; Haack, Jereme N.; Hernandez, George; Katipamula, Srinivas; Widergren, Steven E.

    2015-07-01

    The U.S. Department of Energy’s (DOE’s) Building Technologies Office (BTO) is supporting the development of a “transactional network” concept that supports energy, operational, and financial transactions between building systems (e.g., rooftop units -- RTUs), and the electric power grid using applications, or 'agents', that reside either on the equipment, on local building controllers, or in the Cloud. The transactional network vision is delivered using a real-time, scalable reference platform called VOLTTRON that supports the needs of the changing energy system. VOLTTRON is an agent execution and an innovative distributed control and sensing software platform that supports modern control strategies, including agent-based and transaction-based controls. It enables mobile and stationary software agents to perform information gathering, processing, and control actions.

  13. [Long-term pediatric opioid based pain control. Case reports].

    PubMed

    Zernikow, B; Schiessl, C; Wamsler, C; Griessinger, N; Sittl, R

    2005-10-01

    Based on 4 case reports we focus on the peculiarities of long-term pediatric opioid based pain control. Case report #1, emphasizing the importance of adequate opioid dosing with reference to body weight, illustrates that with adequate management oral sustained-release opioid therapy is safe even in infants less than one year old. Case report #2 is the first report on the usage of buccal fentanyl citrate for pediatric break-through pain control. Case report #3 focuses on the adverse effects of opioid pain control in an infant with neurological impairment. Case report #4 reports on the successful tumor pain control using transdermal buprenorphine. We conclude that proven therapeutic strategies for opioid pain control as applied in adults may be adopted for the usage on children in pediatrics. However, it is mandatory to take into account both the pharmacokinetic and pharmacodynamic peculiarities of childhood. PMID:16080016

  14. REAL-TIME MODEL-BASED ELECTRICAL POWERED WHEELCHAIR CONTROL

    PubMed Central

    Wang, Hongwu; Salatin, Benjamin; Grindle, Garrett G.; Ding, Dan; Cooper, Rory A.

    2009-01-01

    The purpose of this study was to evaluate the effects of three different control methods on driving speed variation and wheel-slip of an electric-powered wheelchair (EPW). A kinematic model as well as 3-D dynamic model was developed to control the velocity and traction of the wheelchair. A smart wheelchair platform was designed and built with a computerized controller and encoders to record wheel speeds and to detect the slip. A model based, a proportional-integral-derivative (PID) and an open-loop controller were applied with the EPW driving on four different surfaces at three specified speeds. The speed errors, variation, rise time, settling time and slip coefficient were calculated and compared for a speed step-response input. Experimental results showed that model based control performed best on all surfaces across the speeds. PMID:19733494

  15. Analysis and design of robust decentralized controllers for nonlinear systems

    SciTech Connect

    Schoenwald, D.A.

    1993-07-01

    Decentralized control strategies for nonlinear systems are achieved via feedback linearization techniques. New results on optimization and parameter robustness of non-linear systems are also developed. In addition, parametric uncertainty in large-scale systems is handled by sensitivity analysis and optimal control methods in a completely decentralized framework. This idea is applied to alleviate uncertainty in friction parameters for the gimbal joints on Space Station Freedom. As an example of decentralized nonlinear control, singular perturbation methods and distributed vibration damping are merged into a control strategy for a two-link flexible manipulator.

  16. Adaptive control with an expert system based supervisory level. Thesis

    NASA Technical Reports Server (NTRS)

    Sullivan, Gerald A.

    1991-01-01

    Adaptive control is presently one of the methods available which may be used to control plants with poorly modelled dynamics or time varying dynamics. Although many variations of adaptive controllers exist, a common characteristic of all adaptive control schemes, is that input/output measurements from the plant are used to adjust a control law in an on-line fashion. Ideally the adjustment mechanism of the adaptive controller is able to learn enough about the dynamics of the plant from input/output measurements to effectively control the plant. In practice, problems such as measurement noise, controller saturation, and incorrect model order, to name a few, may prevent proper adjustment of the controller and poor performance or instability result. In this work we set out to avoid the inadequacies of procedurally implemented safety nets, by introducing a two level control scheme in which an expert system based 'supervisor' at the upper level provides all the safety net functions for an adaptive controller at the lower level. The expert system is based on a shell called IPEX, (Interactive Process EXpert), that we developed specifically for the diagnosis and treatment of dynamic systems. Some of the more important functions that the IPEX system provides are: (1) temporal reasoning; (2) planning of diagnostic activities; and (3) interactive diagnosis. Also, because knowledge and control logic are separate, the incorporation of new diagnostic and treatment knowledge is relatively simple. We note that the flexibility available in the system to express diagnostic and treatment knowledge, allows much greater functionality than could ever be reasonably expected from procedural implementations of safety nets. The remainder of this chapter is divided into three sections. In section 1.1 we give a detailed review of the literature in the area of supervisory systems for adaptive controllers. In particular, we describe the evolution of safety nets from simple ad hoc techniques, up

  17. A new class of energy based control laws for revolute robot arms - Tracking control, robustness enhancement and adaptive control

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Kreutz, Kenneth; Bayard, David S.

    1988-01-01

    A class of joint-level control laws for all-revolute robot arms is introduced. The analysis is similar to the recently proposed energy Liapunov function approach except that the closed-loop potential function is shaped in accordance with the underlying joint space topology. By using energy Liapunov functions with the modified potential energy, a much simpler analysis can be used to show closed-loop global asymptotic stability and local exponential stability. When Coulomb and viscous friction and model parameter errors are present, a sliding-mode-like modification of the control law is proposed to add a robustness-enhancing outer loop. Adaptive control is also addressed within the same framework. A linear-in-the-parameters formulation is adopted, and globally asymptotically stable adaptive control laws are derived by replacing the model parameters in the nonadaptive control laws by their estimates.

  18. Controllable Solid Propulsion Combustion and Acoustic Knowledge Base Improvements

    NASA Technical Reports Server (NTRS)

    McCauley, Rachel; Fischbach, Sean; Fredrick, Robert

    2012-01-01

    Controllable solid propulsion systems have distinctive combustion and acoustic environments that require enhanced testing and analysis techniques to progress this new technology from development to production. In a hot gas valve actuating system, the movement of the pintle through the hot gas exhibits complex acoustic disturbances and flow characteristics that can amplify induced pressure loads that can damage or detonate the rocket motor. The geometry of a controllable solid propulsion gas chamber can set up unique unsteady flow which can feed acoustic oscillations patterns that require characterization. Research in this area aids in the understanding of how best to design, test, and analyze future controllable solid rocket motors using the lessons learned from past government programs as well as university research and testing. This survey paper will give the reader a better understanding of the potentially amplifying affects propagated by a controllable solid rocket motor system and the knowledge of the tools current available to address these acoustic disturbances in a preliminary design. Finally the paper will supply lessons learned from past experiences which will allow the reader to come away with understanding of what steps need to be taken when developing a controllable solid rocket propulsion system. The focus of this survey will be on testing and analysis work published by solid rocket programs and from combustion and acoustic books, conference papers, journal articles, and additionally from subject matter experts dealing currently with controllable solid rocket acoustic analysis.

  19. Implementation of hazard analysis critical control point in jameed production.

    PubMed

    Al-Saed, A K; Al-Groum, R M; Al-Dabbas, M M

    2012-06-01

    The average of standard plate count and coliforms, Staphylococcus aureus and Salmonella counts for three home-made jameed samples, a traditional fermented dairy product, before applying hazard analysis critical control point system were 2.1 × 10(3), 8.9 × 10(1), 4 × 10(1) and less than 10 cfu/g, respectively. The developed hazard analysis critical control point plan resulted in identifying ten critical control points in the flow chart of jameed production. The critical control points included fresh milk receiving, pasteurization, addition of starter, water and salt, straining, personnel hygiene, drying and packaging. After applying hazard analysis critical control point system, there was significant improvement in the microbiological quality of the home-made jameed. The standard plate count was reduced to 3.1 × 10(2) cfu/g whereas coliform and Staphylococcus aureus counts were less than 10 cfu/g and Salmonella was not detected. Sensory evaluation results of color and flavor of sauce prepared from jameed showed a significant increase in the average scores given after hazard analysis critical control point application. PMID:22701056

  20. Effects of a 3-Year Nurse-Based Case Management in Aged Patients with Acute Myocardial Infarction on Rehospitalisation, Mortality, Risk Factors, Physical Functioning and Mental Health. A Secondary Analysis of the Randomized Controlled KORINNA Study

    PubMed Central

    Kirchberger, Inge; Hunger, Matthias; Stollenwerk, Björn; Seidl, Hildegard; Burkhardt, Katrin; Kuch, Bernhard; Meisinger, Christa; Holle, Rolf

    2015-01-01

    Background Home-based secondary prevention programs led by nurses have been proposed to facilitate patients’ adjustment to acute myocardial infarction (AMI). The objective of this study was to conduct secondary analyses of the three-year follow-up of a nurse-based case management for elderly patients discharged from hospital after an AMI. Methods In a single-centre randomized two-armed parallel group trial of hospitalized patients with AMI ≥65 years, patients hospitalized between September 2008 and May 2010 in the Hospital of Augsburg, Germany, were randomly assigned to case management or usual care. The case-management intervention consisted of a nurse-based follow-up for three years including home visits and telephone calls. Study endpoints were time to first unplanned readmission or death, clinical parameters, functional status, depressive symptoms and malnutrition risk. Persons who assessed three-year outcomes and validated readmission data were blinded. The intention-to-treat approach was applied to the statistical analyses which included Cox Proportional Hazards models. Results Three hundred forty patients were allocated to receive case-management (n = 168) or usual care (n = 172). During three years, in the intervention group there were 80 first unplanned readmissions and 6 deaths, while the control group had 111first unplanned readmissions and 3 deaths. The intervention did not significantly affect time to first unplanned readmission or death (Hazard Ratio 0.89, 95% confidence interval (CI) 0.67–1.19; p = 0.439), blood pressure, cholesterol level, instrumental activities of daily life (IADL) (only for men), and depressive symptoms. However, patients in the intervention group had a significantly better functional status, as assessed by the HAQ Disability Index, IADL (only for women), and hand grip strength, and better SCREEN-II malnutrition risk scores than patients in the control group. Conclusions A nurse-based management among elderly patients with

  1. An Information-Based Learning Approach to Dual Control.

    PubMed

    Alpcan, Tansu; Shames, Iman

    2015-11-01

    Dual control aims to concurrently learn and control an unknown system. However, actively learning the system conflicts directly with any given control objective for it will disturb the system during exploration. This paper presents a receding horizon approach to dual control, where a multiobjective optimization problem is solved repeatedly and subject to constraints representing system dynamics. Balancing a standard finite-horizon control objective, a knowledge gain objective is defined to explicitly quantify the information acquired when learning the system dynamics. Measures from information theory, such as entropy-based uncertainty, Fisher information, and relative entropy, are studied and used to quantify the knowledge gained as a result of the control actions. The resulting iterative framework is applied to Markov decision processes and discrete-time nonlinear systems. Thus, the broad applicability and usefulness of the presented approach is demonstrated in diverse problem settings. The framework is illustrated with multiple numerical examples. PMID:25730828

  2. Independent Orbiter Assessment (IOA): Analysis of the guidance, navigation, and control subsystem

    NASA Technical Reports Server (NTRS)

    Trahan, W. H.; Odonnell, R. A.; Pietz, K. C.; Hiott, J. M.

    1986-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) is presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results corresponding to the Orbiter Guidance, Navigation, and Control (GNC) Subsystem hardware are documented. The function of the GNC hardware is to respond to guidance, navigation, and control software commands to effect vehicle control and to provide sensor and controller data to GNC software. Some of the GNC hardware for which failure modes analysis was performed includes: hand controllers; Rudder Pedal Transducer Assembly (RPTA); Speed Brake Thrust Controller (SBTC); Inertial Measurement Unit (IMU); Star Tracker (ST); Crew Optical Alignment Site (COAS); Air Data Transducer Assembly (ADTA); Rate Gyro Assemblies; Accelerometer Assembly (AA); Aerosurface Servo Amplifier (ASA); and Ascent Thrust Vector Control (ATVC). The IOA analysis process utilized available GNC hardware drawings, workbooks, specifications, schematics, and systems briefs for defining hardware assemblies, components, and circuits. Each hardware item was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

  3. Chapter 11. Community analysis-based methods

    SciTech Connect

    Cao, Y.; Wu, C.H.; Andersen, G.L.; Holden, P.A.

    2010-05-01

    Microbial communities are each a composite of populations whose presence and relative abundance in water or other environmental samples are a direct manifestation of environmental conditions, including the introduction of microbe-rich fecal material and factors promoting persistence of the microbes therein. As shown by culture-independent methods, different animal-host fecal microbial communities appear distinctive, suggesting that their community profiles can be used to differentiate fecal samples and to potentially reveal the presence of host fecal material in environmental waters. Cross-comparisons of microbial communities from different hosts also reveal relative abundances of genetic groups that can be used to distinguish sources. In increasing order of their information richness, several community analysis methods hold promise for MST applications: phospholipid fatty acid (PLFA) analysis, denaturing gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (TRFLP), cloning/sequencing, and PhyloChip. Specific case studies involving TRFLP and PhyloChip approaches demonstrate the ability of community-based analyses of contaminated waters to confirm a diagnosis of water quality based on host-specific marker(s). The success of community-based MST for comprehensively confirming fecal sources relies extensively upon using appropriate multivariate statistical approaches. While community-based MST is still under evaluation and development as a primary diagnostic tool, results presented herein demonstrate its promise. Coupled with its inherently comprehensive ability to capture an unprecedented amount of microbiological data that is relevant to water quality, the tools for microbial community analysis are increasingly accessible, and community-based approaches have unparalleled potential for translation into rapid, perhaps real-time, monitoring platforms.

  4. Is there a place for hair analysis in doping controls?

    PubMed

    Rivier, L

    2000-01-10

    The actual antidoping control rules applied in sports (as established by the International Olympic Committee and the International Sport Federations) state that a positive case is chemically established by the unequivocal detection of a forbidden parent molecule and/or any of its metabolite(s) in urine, no matter the amounts which were administered and when the drug was taken. Screening is accomplished most of the time by using GC-MS procedures. These have been optimized to detect most if not all of the forbidden compounds which are put on a list. Recently, attempts have been made on scalp hair to demonstrate the value of this matrix as a possible means for differentiating between therapeutic use and doping abuse. In particular, GC-mass selective detector and GC-high resolution MS were successfully applied to treated animals and body-builders for anabolic agents (steroids and beta-2-agonists) at high sensitivity detection (low ng/g level). Naturally occurring molecules, like testosterone and its metabolites, could also be differentiated from their synthetic counterparts. Positive cases are more often challenged in courts and retrospectivity in time of the drug(s) intake is becoming an important issue for evaluating the responsibility of the person. This is can be based on hair analyses if the drugs have been taken at regular intervals. Stimulants and narcotics are often used in sports like drug of abuse in the ordinary social contexts. On the other hand, anabolic agents, when taken to improve the physical performances, follow complex regimens with the mixing of various formulas and dosages. Scalp hair references ranges for these as well as for endogenous substances still wait to be established statistically for competing, well-trained athletes. The incorporation rate into blond or gray hair is poorer than that of dark colored hair raising the question of individuals equality against the controls, a very important matter of concern for the sport's governing bodies

  5. Low-Cost Undergraduate Control Systems Experiments Using Microcontroller-Based Control of a DC Motor

    ERIC Educational Resources Information Center

    Gunasekaran, M.; Potluri, R.

    2012-01-01

    This paper presents low-cost experiments for a control systems laboratory module that is worth one and a third credits. The experiments are organized around the microcontroller-based control of a permanent magnet dc motor. The experimental setups were built in-house. Except for the operating system, the software used is primarily freeware or free…

  6. An Entry Flight Controls Analysis for a Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Calhoun, Philip

    2000-01-01

    The NASA Langley Research Center has been performing studies to address the feasibility of various single-stage to orbit concepts for use by NASA and the commercial launch industry to provide a lower cost access to space. Some work on the conceptual design of a typical lifting body concept vehicle, designated VentureStar(sup TM) has been conducted in cooperation with the Lockheed Martin Skunk Works. This paper will address the results of a preliminary flight controls assessment of this vehicle concept during the atmospheric entry phase of flight. The work includes control analysis from hypersonic flight at the atmospheric entry through supersonic speeds to final approach and landing at subsonic conditions. The requirements of the flight control effectors are determined over the full range of entry vehicle Mach number conditions. The analysis was performed for a typical maximum crossrange entry trajectory utilizing angle of attack to limit entry heating and providing for energy management, and bank angle to modulation of the lift vector to provide downrange and crossrange capability to fly the vehicle to a specified landing site. Sensitivity of the vehicle open and closed loop characteristics to CG location, control surface mixing strategy and wind gusts are included in the results. An alternative control surface mixing strategy utilizing a reverse aileron technique demonstrated a significant reduction in RCS torque and fuel required to perform bank maneuvers during entry. The results of the control analysis revealed challenges for an early vehicle configuration in the areas of hypersonic pitch trim and subsonic longitudinal controllability.

  7. Cost-effectiveness analysis of optimal control measures for tuberculosis.

    PubMed

    Rodrigues, Paula; Silva, Cristiana J; Torres, Delfim F M

    2014-10-01

    We propose and analyze an optimal control problem where the control system is a mathematical model for tuberculosis that considers reinfection. The control functions represent the fraction of early latent and persistent latent individuals that are treated. Our aim was to study how these control measures should be implemented, for a certain time period, in order to reduce the number of active infected individuals, while minimizing the interventions implementation costs. The optimal intervention is compared along different epidemiological scenarios, by varying the transmission coefficient. The impact of variation of the risk of reinfection, as a result of acquired immunity to a previous infection for treated individuals on the optimal controls and associated solutions, is analyzed. A cost-effectiveness analysis is done, to compare the application of each one of the control measures, separately or in combination. PMID:25245395

  8. Vision-based control in driving assistance of agricultural vehicles

    SciTech Connect

    Khadraoui, D.; Martinet, P.; Bonton, P.; Gallice, J.; Debain, C.; Rouveure, R.

    1998-10-01

    This article presents a real-time control system for an agricultural mobile machine (vehicle) based on an on-board vision system using a single camera. This system has been designed to help humans in repetitive and difficult tasks in the agricultural domain. The aim of the robotics application concerns the control of the vehicle with regard to the reap limit detected in image space. The perception aspect in relation to the application has been described in previous work, and here the authors deal with the control aspect. They integrate image features issues from the modeling of the scene in the control loop to perform an image-based servoing technique. The vehicle behavior described here concerns bicycle and neural models, and three control laws are then synthesized. The first and the second are modeling approaches and use an interaction between the scene and the image space. They are based on the regulation of a task function. The third is a black-box modeling technique, and is based on a neural network. Finally, experimental results obtained with these different control laws in different conditions are presented and discussed.

  9. Knowledge-based processing for aircraft flight control

    NASA Technical Reports Server (NTRS)

    Painter, John H.; Glass, Emily; Economides, Gregory; Russell, Paul

    1994-01-01

    This Contractor Report documents research in Intelligent Control using knowledge-based processing in a manner dual to methods found in the classic stochastic decision, estimation, and control discipline. Such knowledge-based control has also been called Declarative, and Hybid. Software architectures were sought, employing the parallelism inherent in modern object-oriented modeling and programming. The viewpoint adopted was that Intelligent Control employs a class of domain-specific software architectures having features common over a broad variety of implementations, such as management of aircraft flight, power distribution, etc. As much attention was paid to software engineering issues as to artificial intelligence and control issues. This research considered that particular processing methods from the stochastic and knowledge-based worlds are duals, that is, similar in a broad context. They provide architectural design concepts which serve as bridges between the disparate disciplines of decision, estimation, control, and artificial intelligence. This research was applied to the control of a subsonic transport aircraft in the airport terminal area.

  10. Structural control design based on reduced-order observer

    NASA Technical Reports Server (NTRS)

    Su, Tzu-Jeng; Craig, Roy R., Jr.

    1991-01-01

    An observer-based structural control design method is proposed in this paper. The method is a semi-inverse design procedure in that the control law is not designed before the observer system, but is a result that comes from the observer design. However, the observer design is not completely independent of the control design either, but seeks to yield a control law that is close to a prescribed control law. First, the observer design problem is considered as the reconstruction of a linear function of the state vector. The linear state function to be reconstructed is the given control law. Then, based on the derivation for linear state function observers, the observer design is formulated as a parameter optimization problem. The optimization objective is to generate a matrix that is close to the optimal feedback gain matrix. Based on that matrix, the form of the observer and a new control law can be determined. The semi-inverse design procedure can yield a reduced-order observer with dimension considerably smaller than that of the system. Two examples are used to demonstrate the proposed design procedure.

  11. Network-based modular latent structure analysis

    PubMed Central

    2014-01-01

    Background High-throughput expression data, such as gene expression and metabolomics data, exhibit modular structures. Groups of features in each module follow a latent factor model, while between modules, the latent factors are quasi-independent. Recovering the latent factors can shed light on the hidden regulation patterns of the expression. The difficulty in detecting such modules and recovering the latent factors lies in the high dimensionality of the data, and the lack of knowledge in module membership. Methods Here we describe a method based on community detection in the co-expression network. It consists of inference-based network construction, module detection, and interacting latent factor detection from modules. Results In simulations, the method outperformed projection-based modular latent factor discovery when the input signals were not Gaussian. We also demonstrate the method's value in real data analysis. Conclusions The new method nMLSA (network-based modular latent structure analysis) is effective in detecting latent structures, and is easy to extend to non-linear cases. The method is available as R code at http://web1.sph.emory.edu/users/tyu8/nMLSA/. PMID:25435002

  12. A disturbance based control/structure design algorithm

    NASA Technical Reports Server (NTRS)

    Mclaren, Mark D.; Slater, Gary L.

    1989-01-01

    Some authors take a classical approach to the simultaneous structure/control optimization by attempting to simultaneously minimize the weighted sum of the total mass and a quadratic form, subject to all of the structural and control constraints. Here, the optimization will be based on the dynamic response of a structure to an external unknown stochastic disturbance environment. Such a response to excitation approach is common to both the structural and control design phases, and hence represents a more natural control/structure optimization strategy than relying on artificial and vague control penalties. The design objective is to find the structure and controller of minimum mass such that all the prescribed constraints are satisfied. Two alternative solution algorithms are presented which have been applied to this problem. Each algorithm handles the optimization strategy and the imposition of the nonlinear constraints in a different manner. Two controller methodologies, and their effect on the solution algorithm, will be considered. These are full state feedback and direct output feedback, although the problem formulation is not restricted solely to these forms of controller. In fact, although full state feedback is a popular choice among researchers in this field (for reasons that will become apparent), its practical application is severely limited. The controller/structure interaction is inserted by the imposition of appropriate closed-loop constraints, such as closed-loop output response and control effort constraints. Numerical results will be obtained for a representative flexible structure model to illustrate the effectiveness of the solution algorithms.

  13. Implementing context and team based access control in healthcare intranets.

    PubMed

    Georgiadis, Christos K; Mavridis, Ioannis K; Nikolakopoulou, Georgia; Pangalos, George I

    2002-09-01

    The establishment of an efficient access control system in healthcare intranets is a critical security issue directly related to the protection of patients' privacy. Our C-TMAC (Context and Team-based Access Control) model is an active security access control model that layers dynamic access control concepts on top of RBAC (Role-based) and TMAC (Team-based) access control models. It also extends them in the sense that contextual information concerning collaborative activities is associated with teams of users and user permissions are dynamically filtered during runtime. These features of C-TMAC meet the specific security requirements of healthcare applications. In this paper, an experimental implementation of the C-TMAC model is described. More specifically, we present the operational architecture of the system that is used to implement C-TMAC security components in a healthcare intranet. Based on the technological platform of an Oracle Data Base Management System and Application Server, the application logic is coded with stored PL/SQL procedures that include Dynamic SQL routines for runtime value binding purposes. The resulting active security system adapts to current need-to-know requirements of users during runtime and provides fine-grained permission granularity. Apart from identity certificates for authentication, it uses attribute certificates for communicating critical security metadata, such as role membership and team participation of users. PMID:12507264

  14. Neural Network-Based Resistance Spot Welding Control and Quality Prediction

    SciTech Connect

    Allen, J.D., Jr.; Ivezic, N.D.; Zacharia, T.

    1999-07-10

    This paper describes the development and evaluation of neural network-based systems for industrial resistance spot welding process control and weld quality assessment. The developed systems utilize recurrent neural networks for process control and both recurrent networks and static networks for quality prediction. The first section describes a system capable of both welding process control and real-time weld quality assessment, The second describes the development and evaluation of a static neural network-based weld quality assessment system that relied on experimental design to limit the influence of environmental variability. Relevant data analysis methods are also discussed. The weld classifier resulting from the analysis successfldly balances predictive power and simplicity of interpretation. The results presented for both systems demonstrate clearly that neural networks can be employed to address two significant problems common to the resistance spot welding industry, control of the process itself, and non-destructive determination of resulting weld quality.

  15. Monitoring and Control Interface Based on Virtual Sensors

    PubMed Central

    Escobar, Ricardo F.; Adam-Medina, Manuel; García-Beltrán, Carlos D.; Olivares-Peregrino, Víctor H.; Juárez-Romero, David; Guerrero-Ramírez, Gerardo V.

    2014-01-01

    In this article, a toolbox based on a monitoring and control interface (MCI) is presented and applied in a heat exchanger. The MCI was programed in order to realize sensor fault detection and isolation and fault tolerance using virtual sensors. The virtual sensors were designed from model-based high-gain observers. To develop the control task, different kinds of control laws were included in the monitoring and control interface. These control laws are PID, MPC and a non-linear model-based control law. The MCI helps to maintain the heat exchanger under operation, even if a temperature outlet sensor fault occurs; in the case of outlet temperature sensor failure, the MCI will display an alarm. The monitoring and control interface is used as a practical tool to support electronic engineering students with heat transfer and control concepts to be applied in a double-pipe heat exchanger pilot plant. The method aims to teach the students through the observation and manipulation of the main variables of the process and by the interaction with the monitoring and control interface (MCI) developed in LabVIEW©. The MCI provides the electronic engineering students with the knowledge of heat exchanger behavior, since the interface is provided with a thermodynamic model that approximates the temperatures and the physical properties of the fluid (density and heat capacity). An advantage of the interface is the easy manipulation of the actuator for an automatic or manual operation. Another advantage of the monitoring and control interface is that all algorithms can be manipulated and modified by the users. PMID:25365462

  16. Monitoring and control interface based on virtual sensors.

    PubMed

    Escobar, Ricardo F; Adam-Medina, Manuel; García-Beltrán, Carlos D; Olivares-Peregrino, Víctor H; Juárez-Romero, David; Guerrero-Ramírez, Gerardo V

    2014-01-01

    In this article, a toolbox based on a monitoring and control interface (MCI) is presented and applied in a heat exchanger. The MCI was programed in order to realize sensor fault detection and isolation and fault tolerance using virtual sensors. The virtual sensors were designed from model-based high-gain observers. To develop the control task, different kinds of control laws were included in the monitoring and control interface. These control laws are PID, MPC and a non-linear model-based control law. The MCI helps to maintain the heat exchanger under operation, even if a temperature outlet sensor fault occurs; in the case of outlet temperature sensor failure, the MCI will display an alarm. The monitoring and control interface is used as a practical tool to support electronic engineering students with heat transfer and control concepts to be applied in a double-pipe heat exchanger pilot plant. The method aims to teach the students through the observation and manipulation of the main variables of the process and by the interaction with the monitoring and control interface (MCI) developed in LabVIEW©. The MCI provides the electronic engineering students with the knowledge of heat exchanger behavior, since the interface is provided with a thermodynamic model that approximates the temperatures and the physical properties of the fluid (density and heat capacity). An advantage of the interface is the easy manipulation of the actuator for an automatic or manual operation. Another advantage of the monitoring and control interface is that all algorithms can be manipulated and modified by the users. PMID:25365462

  17. SENNA: device for explosives' detection based on nanosecond neutron analysis

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Andrey; Evsenin, Alexey; Osetrov, Oleg; Vakhtin, Dmitry; Gorshkov, Igor

    2006-05-01

    Portable device for explosives' detection (SENNA) based on Nanosecond Neutron Analysis (NNA) / Associated Particles Technique (APT) has been created and tested. SENNA is a single suitcase weighting 35 kg; it is remotely controlled from any PC-compatible computer. Inside is an APT neutron generator with a 3×3 matrix of semiconductor detectors of associated alpha-particles, two BGO-based detectors of gamma-rays, fully-digital data acquisition electronics, data analysis and decision-making software, and batteries. Detection technology is based on determining chemical composition of the concealed substance by analyzing secondary gamma-rays from interaction of tagged fast neutrons with its material. A combination of position-sensitive alpha-detector and time-of-flight analysis allows one to determine the location of the detected material within the inspected volume and its approximate mass. Fully digital data acquisition electronics is capable of performing alpha-gamma coincidence analysis at very high counting rates, which leads to reduction of the detection time down to dozens of seconds. SENNA's scenario-driven automatic decisionmaking algorithm based of "fuzzy logic" mechanism allows one to detect not only standard military or industrial explosives, but also improvised explosives (including those containing no nitrogen), even if their chemical composition differs from that of standard explosives. SENNA can also be "trained" to detect other hazardous materials, such as chemical/toxic materials, if their chemical composition is in any way different from that of the surrounding materials.

  18. Planner-Based Control of Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Muscettola, Nicola; Kortenkamp, David; Fry, Chuck; Bell, Scott

    2005-01-01

    The paper describes an approach to the integration of qualitative and quantitative modeling techniques for advanced life support (ALS) systems. Developing reliable control strategies that scale up to fully integrated life support systems requires augmenting quantitative models and control algorithms with the abstractions provided by qualitative, symbolic models and their associated high-level control strategies. This will allow for effective management of the combinatorics due to the integration of a large number of ALS subsystems. By focusing control actions at different levels of detail and reactivity we can use faster: simpler responses at the lowest level and predictive but complex responses at the higher levels of abstraction. In particular, methods from model-based planning and scheduling can provide effective resource management over long time periods. We describe reference implementation of an advanced control system using the IDEA control architecture developed at NASA Ames Research Center. IDEA uses planning/scheduling as the sole reasoning method for predictive and reactive closed loop control. We describe preliminary experiments in planner-based control of ALS carried out on an integrated ALS simulation developed at NASA Johnson Space Center.

  19. Mercury Control with Calcium-Based Sorbents and Oxidizing Agents

    SciTech Connect

    Thomas K. Gale

    2005-07-01

    This Final Report contains the test descriptions, results, analysis, correlations, theoretical descriptions, and model derivations produced from many different investigations performed on a project funded by the U.S. Department of Energy, to investigate calcium-based sorbents and injection of oxidizing agents for the removal of mercury. Among the technologies were (a) calcium-based sorbents in general, (b) oxidant-additive sorbents developed originally at the EPA, and (c) optimized calcium/carbon synergism for mercury-removal enhancement. In addition, (d) sodium-tetrasulfide injection was found to effectively capture both forms of mercury across baghouses and ESPs, and has since been demonstrated at a slipstream treating PRB coal. It has been shown that sodium-tetrasulfide had little impact on the foam index of PRB flyash, which may indicate that sodium-tetrasulfide injection could be used at power plants without affecting flyash sales. Another technology, (e) coal blending, was shown to be an effective means of increasing mercury removal, by optimizing the concentration of calcium and carbon in the flyash. In addition to the investigation and validation of multiple mercury-control technologies (a through e above), important fundamental mechanism governing mercury kinetics in flue gas were elucidated. For example, it was shown, for the range of chlorine and unburned-carbon (UBC) concentrations in coal-fired utilities, that chlorine has much less effect on mercury oxidation and removal than UBC in the flyash. Unburned carbon enhances mercury oxidation in the flue gas by reacting with HCl to form chlorinated-carbon sites, which then react with elemental mercury to form mercuric chloride, which subsequently desorbs back into the flue gas. Calcium was found to enhance mercury removal by stabilizing the oxidized mercury formed on carbon surfaces. Finally, a model was developed to describe these mercury adsorption, desorption, oxidation, and removal mechanisms, including

  20. Position Sensorless Control of IPMSMs Based on a Novel Flux Model Suitable for Maximum Torque Control

    NASA Astrophysics Data System (ADS)

    Matsumoto, Atsushi; Hasegawa, Masaru; Matsui, Keiju

    In this paper, a novel position sensorless control method for interior permanent magnet synchronous motors (IPMSMs) that is based on a novel flux model suitable for maximum torque control has been proposed. Maximum torque per ampere (MTPA) control is often utilized for driving IPMSMs with the maximum efficiency. In order to implement this control, generally, the parameters are required to be accurate. However, the inductance varies dramatically because of magnetic saturation, which has been one of the most important problems in recent years. Therefore, the conventional MTPA control method fails to achieve maximum efficiency for IPMSMs because of parameter mismatches. In this paper, first, a novel flux model has been proposed for realizing the position sensorless control of IPMSMs, which is insensitive to Lq. In addition, in this paper, it has been shown that the proposed flux model can approximately estimate the maximum torque control (MTC) frame, which as a new coordinate aligned with the current vector for MTPA control. Next, in this paper, a precise estimation method for the MTC frame has been proposed. By this method, highly accurate maximum torque control can be achieved. A decoupling control algorithm based on the proposed model has also been addressed in this paper. Finally, some experimental results demonstrate the feasibility and effectiveness of the proposed method.